JPH11117070A - Chemical vapor deposition equipment - Google Patents

Abstract

(57) [Problem] An object of the present invention is to achieve a reduction in film formation time and a saving of raw materials. SOLUTION: When the inlet valves 17a, 17b, 17c are closed, the chemical vapors generated by the corresponding raw material vapor generators 16a, 16b, 16c are temporarily stored when being disposed on a transportation pipe for transporting the chemical vapors. , Inlet valve 17a, 1
At the time of opening of 7b, 17c, the raw material steam generator 16a,
It is characterized by having raw material vapor storage containers 18a, 18b, 18c for sending the chemical vapor temporarily stored together with the chemical vapor generated in 16b, 16c to the reactor 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical vapor deposition apparatus for forming, for example, a single crystal film or the like by means of intermittent vapor-phase vapor deposition (hereinafter referred to as intermittent CVD).

[0002]

2. Description of the Related Art A single crystal film or a uniaxially oriented polycrystalline film is
Since the crystallinity is more uniform than amorphous films and non-oriented polycrystalline films, the physical properties unique to the material, such as conductivity, dielectric, insulating, ferroelectric, superconductivity, semiconductor properties, and magneto-optical properties It has the feature that various properties and anisotropy of these properties appear strongly and sharply. Therefore, it is useful in various industrial fields, and its realization is desired. In recent years, attempts have been actively made to deposit high-value integrated circuits and smart devices by depositing a single crystal film of a compound or a uniaxial alignment film on a single crystal substrate such as silicon Si or gallium arsenide GaAs. I have.

The intermittent CVD method in which a chemical vapor to be used is intermittently supplied to a reactor to deposit a thin film at an atomic layer level one by one on a substrate is a method of selectively selecting a vapor species matching an atomic layer arrangement of a crystal. Since it can be introduced, it is one of the most suitable methods for forming such a single crystal film or a uniaxial alignment film. As a conventional technique using this intermittent CVD method, for example,
No. 90587 discloses a method of forming a ferroelectric single crystal thin film of lead zirconate titanium (Pb (Zr _x Ti _1-x ) O ₃ ) oriented in the C axis. In this prior art, various organometallic raw material vapors generated by a bubbler in a reactor in an O ₂ or O ₃ atmosphere where a substrate is placed, that is, Pb raw material vapor, Zr raw material vapor, and Ti raw material vapor are shown in FIG. Supply intermittently in such a flow sequence. And while independently controlling the deposition amount and deposition time of the raw material of each constituent element,
TiO ₂ atomic layer, Pb according to atomic layer arrangement in C axis direction
An O atomic layer, a ZrO ₂ atomic layer, and a PbO atomic layer are sequentially deposited, and Pb (Zr _x Ti _1-x ) O ₃ is formed on the substrate in a monomolecular layer or a multilayer according to the stoichiometric composition shown by the molecular formula. By forming and repeating this step a plurality of times until a required film thickness is obtained, a single crystal film or a uniaxial alignment film having a structure in which the molecular layers are stacked is obtained. In this prior art,
Although only organometallic vapor is intermittently supplied, a good quality film can be obtained even if the oxidizing agent O ₂ or O ₃ is intermittently introduced, according to the 1994 Japanese Journal of Applied Ph.
ysics 33, p. 5172. The intermittent CVD method is, of course, extremely effective for forming not only ferroelectric films such as Pb (Zr _x Ti _1-x ) O ₃ but also other crystalline thin films.

[0004]

However, while the conventional intermittent CVD method is useful as a method for forming a high-quality single crystal film or a uniaxially oriented film, it wastes a lot of raw materials, and its solution is strongly desired. Was. Pb (Zr _x Ti _1-x ) described above
This problem is specifically described in the prior art of O ₃ .
When one raw material vapor is introduced into the reaction vessel according to the flow sequence shown in FIG. 4 or when the reaction vessel is evacuated, the remaining raw material vapor is supplied to the reaction vessel in order to avoid instability of the transport amount due to shutoff. It was configured to be bypassed and discarded. For this reason, the consumption of the abatement agent for purifying the raw material and the waste gas has been severe, which has been a factor that increases the process cost. In addition, the intermittent CVD method has a configuration in which chemical vapor is sequentially introduced. Therefore, when a raw material having low volatility is used, the introduction time cannot be sufficiently reduced. There is also a problem that it takes too much time for film formation. When the film shown in FIG.
A cycle = 34 seconds produces a single crystal film of about 8A. This is converted to a growth rate of about 14 A / min. Attempting to obtain a practical film thickness of 1500 A used for a ferroelectric memory or the like at this film forming rate would require 100 minutes or more. This film formation time is too long for use in production, and it has been desired to reduce the film formation time as much as possible.

The present invention has been made in view of such a conventional problem, and can shorten the film forming time and save the raw materials, and can also use two or more chemical vapors at the same timing. An object of the present invention is to provide a chemical vapor deposition apparatus capable of simplifying the apparatus when supplying the same to a reactor.

[0006]

In order to solve the above-mentioned problems, according to the present invention, chemical vapors of different types are respectively generated by a plurality of raw material vapor generators, and the generated chemical vapors are produced. Is transported by a transport pipe, at least one of the plurality of chemical vapors is periodically introduced into the reactor by intermittently opening and closing the inlet valve, and a thin film is formed on a heating substrate provided in the reactor. In the chemical vapor deposition apparatus to be disposed in the middle of the transport pipe, temporarily store the chemical vapor generated in the corresponding raw material steam generator when the inlet valve is closed, and when the inlet valve is opened. The gist of the present invention is to have a raw material vapor storage container for sending the temporarily stored chemical vapor together with the chemical vapor generated by the raw material vapor generator to the reactor. With this configuration, the chemical vapor is continuously generated from the raw material vapor generator during the operation of the apparatus. The chemical vapor is temporarily stored in the raw material vapor storage container during the exhaust period when the inlet valve is closed and the exhaust gas is exhausted from the reactor, and then during the supply period when the inlet valve is opened, the temporarily stored chemical vapor is stored. The vapor and the chemical vapor generated by the raw material vapor generator are simultaneously introduced into the reactor to form a film.

According to a second aspect of the present invention, in the chemical vapor deposition apparatus according to the first aspect, the raw material vapor storage container stores the raw material vapor storage container at a temperature higher than the re-agglomeration temperature of the chemical vapor stored therein. The gist of the invention is to provide a temperature control means for maintaining a constant temperature. According to this configuration, when the chemical vapor has a reagglomeration temperature in a temperature range higher than the normal temperature, the aggregation of the chemical vapor inside the raw material vapor storage container is prevented.

According to a third aspect of the present invention, in the chemical vapor deposition apparatus according to the first aspect, the transportation pipe is provided between a connection point of the raw material vapor storage container and the raw material vapor generator. The gist is that a differential pressure generator for keeping the internal pressure of the raw material steam generator higher than the pressure of the raw material steam storage container is provided. With this configuration, when the inlet valve opens and the pressure in the transport pipe on the reactor side suddenly decreases, the pressure change is suppressed from reaching the raw material steam generator, and chemical vapor is generated at a stable vaporization rate. Will be

According to a fourth aspect of the present invention, in the chemical vapor deposition apparatus according to the first aspect, two or more of the plurality of source steam generators are one source steam storage vessel. And one inlet valve is shared. With this configuration, 2
When two or more kinds of chemical vapors are intermittently supplied to the reactor at the same timing, the second operation is performed by operating one common raw material vapor storage container and opening and closing one inlet valve.
More than one chemical vapor is introduced into the reactor simultaneously.

According to a fifth aspect of the present invention, in the chemical vapor deposition apparatus according to the first aspect, all of the plurality of source vapor generators share one source vapor storage container and one inlet valve. The gist of the invention is that it is configured to With this configuration, when all chemical vapors from a plurality of raw material steam generators are intermittently supplied to the reactor at the same timing, the operation of one common raw material steam storage container and the opening and closing operation of one inlet valve are respectively performed. All the chemical vapors are simultaneously introduced into the reactor.

[0011]

According to the first aspect of the invention, chemical vapor is temporarily stored in the raw material vapor storage container during the exhaust period when the inlet valve is closed, and during the supply period when the inlet valve is opened,
Since the temporarily stored chemical vapor and the chemical vapor generated by the raw material vapor generator are simultaneously introduced into the reactor to form a film, the film formation time can be significantly reduced.
In addition, since the chemical vapor is not drained during the evacuation period, raw materials can be saved.

According to the second aspect of the present invention, the raw material vapor storage container is provided with temperature control means for maintaining the raw material vapor storage container at a constant temperature equal to or higher than the re-coagulation temperature of the chemical vapor to be stored. However, even when the chemical vapor has a re-agglomeration temperature in a temperature range higher than the normal temperature, the chemical vapor is prevented from agglomerating inside the raw material vapor storage container, so the temporarily stored chemical vapor is stored during the supply period. Can be introduced into the reactor, and the film formation time can be reliably reduced.

According to the third aspect of the present invention, the internal pressure of the raw material steam generator can be reduced by changing the internal pressure of the raw material steam generator on the way of the transportation between the connection point of the raw material steam storage container and the raw material steam generator. Since the differential pressure generator that keeps the pressure higher than the side pressure is installed, the chemical vapor is generated at a stable vaporization rate by the raw material vapor generator, and the required amount of chemical vapor is always transported to the raw material vapor storage container and the reactor. And the film formation time can be reliably reduced.

According to a fourth aspect of the present invention, two or more of the plurality of raw material steam generators share one raw material steam storage container and one inlet valve. In the case of forming a film by intermittently supplying a chemical vapor of more than one species to the reactor at the same timing, the supply at the same timing is ensured and the film formation can be surely promoted while simplifying the apparatus configuration.

According to a fifth aspect of the present invention, since all of the plurality of raw material steam generators share one raw material vapor storage container and one inlet valve, all of the plurality of chemical vapors are the same. In the case where the film is formed by intermittent supply to the reactor at the timing, the supply of the plurality of chemical vapors at the same time is guaranteed and the film formation can be surely promoted with further simplification of the apparatus configuration. .

[0016]

Embodiments of the present invention will be described below with reference to the drawings. The chemical vapor deposition apparatus (hereinafter, also referred to as a CVD apparatus) of the present embodiment can be applied to various kinds of CVD raw materials and film types, and therefore, description will be given here with generality. . It is assumed that one or more raw materials A, B, C,... Are used for forming a desired thin film as a premise of the description of each embodiment below.

FIG. 1 to FIG. 8 are views showing a first embodiment of the present invention. First, the overall configuration of the CVD apparatus will be described with reference to FIG. In FIG. 1, reference numeral 1 denotes a reactor system, and the reactor system 1 includes a cold wall type reactor 10 occupying a main part. The reactor 10 includes a susceptor 12 that supports a substrate 11 and maintains the substrate at a predetermined growth temperature, and a chemical vapor (hereinafter, also referred to as a raw material vapor) (A, B,
C,...), An exhaust port 14 serving as an outlet for product gas and unreacted reaction steam, and a pressure gauge 15 for measuring the pressure in the vessel. Although not shown,
The reactor 10 is provided with an access port for taking the substrate 11 out of the reactor. 2 is a raw material vapor supply system.
A raw material supply line 2a, B raw material supply line 2b, C
A raw material supply line 2c is provided. 16a,
Reference numerals 16b, 16c,... Denote raw material steam generators for generating raw material vapor at a predetermined concentration and flow rate. The generated raw material steams A, B, C,. Dedicated remote controllable inlet valve 17
After passing through a, 17b, 17c,..., they are joined and led to the raw material vapor inlet 13. The raw material vapors A, B, C,.
After passing through the inlet valves 17a, 17b, 17c,..., They may be directly introduced into the reactor from respective raw material introduction ports without merging. When a raw material vapor that aggregates at room temperature is used, a heating means is attached to a transport pipe through which the corresponding raw material vapor passes, and the temperature is kept at or above the aggregation temperature. Inlet valve 1
7a, 17b, 17c,... And the raw material steam generators 16a, 1
6b, 16c,... Are provided with dedicated raw material vapor storage containers 18a, 18b, 18c,.
9a, 19b, 19c,... These are important components that characterize the present embodiment. When the inlet valves 17a, 17b, 17c,... Are closed, the raw material vapor storage containers 18a, 18b, 18c,.
The purpose is to temporarily store the raw material steam delivered from the raw material steam generators 16a, 16b, 16c,... The structure is a hollow container that is sealed except for the steam port. The volume is controlled by the inlet valves 17a, 17
, 17c,... and the raw material steam generators 16a, 16b, 16
c, which is sufficiently (for example, 5 times or more) larger than the total internal volume of the transport pipe connecting the c. The raw material vapor storage containers 18a, 18b, 18c,... Using the raw material vapor which is coagulable at room temperature are provided with a heating means having a temperature control function to prevent internal coagulation. On the other hand, the purpose of the differential pressure generators 19a, 19b, 19c,... Is that when the inlet valves 17a, 17b, 17c,. To be transmitted to the containers 16a, 16b, 16c,... Raw material steam generator 16a,
The flow rates and vaporization rates that determine the raw material transport amounts 16b, 16c,... Are extremely sensitive to the pressure in the transport pipe and are unstable with respect to the changes. Differential pressure generators 19a, 19
By providing b, 19c,..., this adverse effect can be avoided. Although any mechanism capable of generating a differential pressure may be used, the simplest and practical differential pressure generator is a needle valve. In the raw material vapor supply line where the vapor is continuously supplied to the reactor, the raw material vapor storage container and the differential pressure generator described here can be omitted. 3 is an evacuation system. A thick stainless steel exhaust pipe connects the exhaust port 14 of the reactor 1 and the vacuum exhaust device 22 via a pair of exhaust main valves 20 and exhaust sub-valves 21 arranged in parallel. The exhaust sub-valve 21 is used in place of the exhaust main valve 20 when forming a film while suppressing the exhaust speed of the vacuum exhaust device 22, and is designed so that the opening diameter at the time of opening can be arbitrarily reduced. . The gas and the like discharged from the evacuation device 22 are purified by an abatement device (not shown) and then discharged to the atmosphere. Reference numeral 4 denotes a valve control device, which includes inlet valves 17a, 17b, 17c,
... The opening / closing timing of the exhaust main valve 20 and the exhaust auxiliary valve 21 is precisely controlled by a program.

The configuration of the raw material steam generators 16a, 16b, 16c,... Will be described in more detail with reference to FIGS. Raw materials used for film formation are originally classified into gaseous ones and ones which vaporize liquids or solids and turn them into vapor. FIG. 2 (a) shows a raw material steam generator of a gaseous raw material (which is not strictly a raw material, but also includes an inert gas introduced into the reactor as a buffer gas). 24 is a raw material cylinder filled with a gas raw material, 25 is a raw material cylinder 24
Is a pressure regulator for making the outlet pressure of the fuel cell constant, and 26 is a mass flow regulator. The raw material gas in the raw material cylinder 24 is supplied to the pressure regulator 2
After the pressure is adjusted in 5, the flow rate is adjusted to a predetermined flow rate by the mass flow controller 26 and transported to the reactor 10. FIG. 2 (b)
Shows a raw material steam generator for liquid raw materials and solid raw materials. 27 gas cylinder filled Ar, He, an inert carrier gas such as N _2, 28 is a gas cylinder 27
Is a pressure regulator for keeping the outlet pressure constant, 29 is a mass flow controller, and 30 is a raw material container having a temperature regulating function. The raw material container 30 is filled with the raw material to be used from the filling port 31 in advance. After the pressure of the carrier gas in the gas cylinder 27 is adjusted by the pressure regulator 28, the carrier gas is adjusted to a predetermined flow rate by the mass flow controller 29, enters the raw material container 30 through the carrier gas inlet 32, and stays in the raw material container 30. The steam is taken in and exits from the raw material steam outlet 33. Thereafter, the raw material vapor and the carrier gas are transported to the reactor 10.

Next, first to third intermittent CVD methods using the above-configured CVD apparatus will be described in order.

The first intermittent CVD method will be described with reference to FIGS. This intermittent CVD method is the simplest method of periodically supplying one type of raw material vapor to the reactor 10 to deposit a thin film. However, there is no unused material supply line.

After the washed substrate 11 is placed on the susceptor 12 heated to a predetermined temperature, the inlet valves 17a,
7b, 17c,... Are all closed, the main exhaust valve 20 is opened, and the vacuum exhaust device 22 is operated to temporarily evacuate the inside of the reactor 10. When the temperature of the substrate 11 is stabilized, the exhaust main valve 20 is closed, the exhaust sub-valve 21 is opened, and thereafter, the reactor 10 is exhausted via the exhaust sub-valve 21. This is the pre-film formation step. The basic operation of the film forming pre-process is substantially the same in the second and subsequent methods described later, and the description thereof will be omitted. When the work of the pre-film formation step is completed, the film formation main step is executed to deposit a thin film on the substrate 11.

FIG. 3 shows the raw material vapor delivered from the raw material vapor generator in the film formation main process (here, the raw material vapor generator 16
FIG. 6 is a time chart of a flow rate L of an A valve from a to a) and an opening / closing state of an inlet valve 17a. t _V is an exhaust period. During this period t _V , the supply of the raw material vapor to the reactor 10 is stopped by closing the inlet valve 17a. t _A is a supply period. During this period t _A , the inlet valve 17a is opened and the supply of the raw material vapor to the reactor 10 is performed. L
= L _A but is delivery rate of the raw material steam generator 16a, it is desirable in the case of a solid or liquid is vaporized steam generator for generating steam is the flow rate of the maximum possible stable supply. The origin of the time axis is A when the raw material steam generator 16a operates.
This is the point in time at which steam delivery starts. First, the raw material steam generator 16a is operated to start sending out the raw material steam _A at the flow rate LA. The raw material vapor A sent from the raw material vapor generator 16a is stored in the raw material vapor storage container 18a for a time t _V. Subsequently, the inlet valve 17a is controlled by a command from the valve controller 4.
Is opened, the A raw material vapor stored in the raw material vapor storage container 18a is sent out to the reactor 10 in a relatively short time, and the A raw material vapor sent out from the raw material steam generator 16a is also supplied to the reactor 10. Supplied directly. Supply time is t _A
It is. Due to the opening of the inlet valve 17a, the pressure inside the raw material vapor storage vessel 18a and the inside of the transport pipe connected to the raw material vapor storage vessel suddenly decrease. However, since the differential pressure generator 19a is provided, the raw material vapor generator 16a is affected by pressure fluctuation. Without receiving
During this time, the raw material vapor can be continuously delivered at a stable transportation speed. Following the inlet valve 17a and closing by a command of the valve control device 4 shifts to an exhaust period t _V. The raw material vapor is discharged from the reactor 10, and the raw material vapor is stored again in the raw material vapor storage container 18a. When the evacuation period t _V ends, the inlet valve 17a is opened, and the supply period t
_Move to _A. A accumulated in the raw material vapor storage container 18a
The raw material vapor and the raw material vapor A sent from the raw material vapor generator 16a are supplied to the reactor 10 again. Thereafter, t _V + t _A
Is defined as one cycle, and this cycle operation is repeated a desired number of times, whereby the film growth proceeds. After the last operation of t _V + t _A is completed, a post-film formation process is started. In the subsequent step, the operation of the raw material vapor generator 16a is stopped, the supply of the raw material vapor is stopped, the exhaust sub-valve 21 is closed, the exhaust main valve 20 is opened, and the inside of the reactor 10 is once evacuated. Thereafter, the main exhaust valve 20 is closed, the reactor 10 is brought to the atmospheric pressure, and the substrate 11 is taken out of the reactor 10. Since the basic operation of the post-film formation process is substantially the same in the second and subsequent methods described later, the description will not be repeated. Thus, all the steps of the first intermittent CVD method are completed.

The effect of the first intermittent CVD method will be described. During the exhaust period t _v in the conventional CVD method, transport of the raw material steam generator in order to (flow rate or vaporization rate) stability, discarded raw steam generated in the raw material steam generator diverts reactor I was shedding. In the first intermittent CVD method according to the present embodiment, the raw material vapor is temporarily stored in the raw material vapor storage container during the period t _V , and is entirely stored in the reactor together with the vapor sent from the raw material vapor generator during the next t _A period. It has a configuration to be introduced. Therefore, there is no waste of the raw material steam, and the raw material consumption is t _A /
(T _A + t _V ). Further, in the present embodiment, since the raw material vapor is no longer abandoned, the consumption of the harm-removing agent used for processing the abandoned raw material vapor in the conventional technique can be completely reduced to zero. further,
The first intermittent CVD method according to the present embodiment has an excellent feature that the processing time for film formation using a liquid or solid material in which a high transport speed is difficult to obtain can be significantly reduced. In order to clarify the effect, the first intermittent CVD method (FIG. 3) in the present embodiment will be compared with a conventional CVD method (FIG. 4). In FIG. 4, t _V ′ is an exhaust period,
t _A ′ is the supply period of the A raw material vapor. To make a fair comparison, we make the following assumptions: In both periods, the same film thickness can be generated in one period. This may be restated as an equal amount of feed vapor being supplied to the reactor during one cycle.
The length of the evacuation period is equal for both (ie, t _V ′ =
t _V ). The raw material steam generator used is a widely used bubbler device, and both use the same one.
Bubbler carrier gas flow rate is saturated carrier gas flow rate L
_It is set to _max . Here, the saturated carrier gas flow rate is the maximum flow rate at which the transport rate of the raw material vapor is proportional to the carrier gas flow rate. Even if the flow rate of the carrier gas is increased to _Lmax or more, the transport speed does not increase above this since the evaporation speed of the raw material controls the transport speed. Since a certain period of time is required for the transfer of gas from the raw material vapor storage container to the reactor, a lower limit is set for t _A in the present embodiment, and this is defined as t _AO .

[0024] In this embodiment, t A raw steam supplied to the reactor in period _A, t _A period and the raw material vapor sent directly from the raw material steam generator, a raw material vapor storage in preceding t _V period This is the sum of the raw material vapors stored in the container, and when expressed numerically with reference to FIG. 3, L _max × (t _A +
t _V ). (Strictly speaking, this value multiplied by the concentration of the raw material vapor is the amount of the raw material vapor). To deposit a thin film having the same thickness as the present embodiment between the conventional one cycle CVD method configured to flow dumped in the exhaust period, during the supply period _{t A 'L max × (t} A + t It is necessary to supply the raw material A of _V ) to the reactor. Since _Lmax is assumed to be constant, in order to realize this, the supply period is set to t _A ′ = t _A
It must be + t _V. By calculating the ratio of one cycle λ of the present embodiment to one cycle λ ′ of the prior art,

[Number 1] _{λ / λ '= (t A} + t V) / (t A' + t V ') = (t A + t V) / (t A + 2t V) <1 ... (1) , and the present embodiment It can be seen that the adoption of (1) has shortened one cycle of the prior art by (t _A + t _V ) / (t _A + 2t _V ). Since the film forming step is an integration time in which the cycle is repeated a predetermined number of times, the time required for the film forming step is also (t _A + t _V ) / (t _A + 2t _V ) by employing this embodiment.
Can only be shortened. The shortest shortening rate is (t _AO + t _V ) / (t _AO + 2t _V ) from the above definition. As described above, the first intermittent CVD method in this embodiment has an effect that the process time required for film formation can be reduced.

The second intermittent CVD method will be described with reference to FIGS. The intermittent CVD method is a method of sequentially supplying three kinds of raw material vapors A, B, and C to the reactor 10 to deposit a thin film. Here, three kinds of raw material vapors are used, but the present invention can be similarly applied to two kinds of raw material vapors and four kinds of raw material vapors.

The substrate 11 is housed in the reactor 10, and after the work of the film forming pre-process, the film forming main process is executed. FIG. 5 shows the flow rates L of the A raw material vapor, B raw material vapor, and C raw material vapor delivered from the raw material vapor generators 16a, 16b, and 16c and the opening and closing states of the inlet valves 17a, 17b, and 17c during the main film forming process. It is a time chart. t _V is an evacuation period. During this period t _V , the supply of all the raw material vapor to the reactor 10 is stopped by closing the inlet valves 17a, 17b, and 17c. t
_A, t _B, t _C, respectively A feedstock vapor, B raw material vapor, C
This is a period during which the raw material vapor is supplied to the reactor 10, and the period t
_A, t _B, t _C, the corresponding inlet valve 17a, 17b,
17 c is opened, and the respective raw material vapors are supplied to the reactor 10. L = L _A , L _B , L _C are A raw material, B raw material, C raw material
The delivery flow rate of the raw material steam generators 16a, 16b, 16c is desirably set to the maximum flow rate at which at least one can be supplied stably. The origin of the time axis is 1
The raw material steam generator 16a of the A raw material vapor
This is the point at which the delivery of the raw material vapor starts. First, the raw material vapor generator 16a is operated to discharge the raw material vapor _A at the flow rate LA. Subsequently, after t _V + t _B , the raw material steam generator 16b
, And after t _V + t _C , the raw material steam generator 16
Activate c. After this, the raw material steam A, the raw material steam B,
The raw material vapor is always temporarily stored in the raw material vapor storage containers 18a, 18b, 18c corresponding to each raw material line while the inlet valves 17a, 17b, 17c are closed. When the raw material steam generator 16a is t from operating _B + t _C + 3t _V time after the inlet valve 17a in the command of the valve control unit 4 is opened by the time t _A, the A raw material vapor that has been stored in the raw material vapor storage container 18a At the same time as being transported to the reactor 10 in a short time, the raw material vapor A delivered from the raw material vapor generator 16a is also directly supplied to the reactor 10. Supply amount of the A material vapor supply period _{(t A + t B + t} C + 3t V) × L A
It is. When the inlet valve 17a is closed, the reactor 10 is evacuated for the time t _V , and the A raw material vapor is completely discharged outside the reactor. T _A + t _C + after the operation of the raw material steam generator 16b
3t _V time after (or inlet valve 17a is after time t _V from the closed), this time by a command of the valve control unit 4 opens only inlet valve 17b is time t _B, have been temporarily stored in the raw material vapor storage container 18b The B raw material vapor and the B raw material vapor delivered from the raw material vapor
To supply. The supply amount during the B raw material vapor supply period is (t _A + t
_B + t _C + 3t _V) is a × L _B. When the inlet valve 17b is closed, the reactor 10 is evacuated for the time t _V , and the B raw material vapor is completely discharged outside the reactor. Raw material steam generator 16c
There after t _A + t _B + 3t _V time after actuation (or inlet valve 17b is after time t _V from the closed), the inlet valve 17c is opened by the time t _C by a command of the valve control device 4, the raw material vapor storage The C raw material vapor temporarily stored in the container 18c and the C raw material vapor directly sent from the raw material vapor generator 16c are supplied to the reactor 10. The supply amount during this C raw material vapor supply period is (t _A + t _B + t _C + 3t _V ) × L _C
It is. When the inlet valve 17c is closed, the reactor 10 is evacuated for the time t _V , and the C raw material vapor is completely discharged outside the reactor. T _B + t since the inlet valve 17a was closed last
After _C + 3t _V time, again inlet valve 17a by a command of the valve control unit 4 is opened by the time t _A, and supplies the A raw steam to the reactor 10. The supply amount of the A material vapor supply period is _{(t A + t B + t} C + 3t V) × L A. When the inlet valve 17a is closed, the reactor 10 is evacuated for the time t _V , and the A raw material vapor is completely discharged outside the reactor. Similarly, after closing the inlet valve 17b lastly, t _A + t _C + 3t _V
After a time, the inlet valve 1 is controlled by a command from the valve controller 4.
7 b is opened for a time t _B to supply the B raw material vapor to the reactor 10. The supply amount during the B raw material vapor supply period is (t _A + t _B
+ T _C + 3t _V) is a × L _B. When the inlet valve 17b is closed, the reactor 10 is evacuated for the time t _V , and the B raw material vapor is completely discharged outside the reactor. Similarly, after a time of t _A + t _B + 3t _V from the last closing of the inlet valve 17c, the inlet valve 17a is again opened for the time t _A by a command from the valve control device 4, and the raw material A vapor is supplied to the reactor 10. . The supply amount during the A raw material vapor supply period is (t _A + t _B + t _C
A + 3t _V) × L _A. When the inlet valve 17b is closed, the reactor 10 is evacuated for the time t _V , and the B raw material vapor is completely discharged outside the reactor. Hereinafter, similarly, the time λ = t
_{V + t A + t V +} t B + t V + t C (= t A + t B + t
_By repeating a cycle of one cycle of ( _C + 3t _V ) a predetermined number of times, a thin film having a desired thickness grows. When the last C raw material vapor supply period is over, the process enters a post-film formation step. Thus, all the steps of the second intermittent CVD method are completed.

The effect of the second intermittent CVD method will be described. In the conventional CVD method, the transport amount (flow rate and vaporization rate) of the raw material vapor generator is during the exhaust period t _V and the supply period of other raw material vapor, for example, during the time t _B + t _C +3 t _{V in the case} of the raw material vapor A. A) to stabilize
The raw material vapor was bypassed to the reactor and discarded. In the second intermittent CVD method according to the present embodiment, the raw material vapor during this period is temporarily stored in the raw material vapor storage container _A , and is supplied to the reactor during the subsequent supply period tA. Therefore, there is no waste of raw material vapor, as compared to the prior art material consumed can be greatly reduced to _{t A / (t A + t} B + t C + 3t V). Further, in the present embodiment, since the raw material vapor is no longer abandoned, the consumption of the harm-removing agent used for processing the abandoned raw material vapor in the conventional technique can be completely reduced to zero. Further, in the second intermittent CVD method according to the present embodiment, the processing time for film formation using a liquid or a solid raw material, for which a high transport speed is difficult to obtain, can be significantly reduced. In order to clarify the effect, the second intermittent CVD method in this embodiment (FIG. 5) and the conventional C
The VD method (FIG. 6) will be described in comparison. In FIG. 6, t _V ′ is an exhaust period, and t _A ′, t _B ′, and t _C ′ are supply periods of A raw material vapor, B raw material vapor, and C raw material vapor. L _A ′,
L _B ′ and L _C ′ are the delivery flow rates of the raw material vapors A, B, and C. To make a fair comparison, we make the following assumptions: , And are the same as the premise in the first intermittent CVD method.
Long raw material bubbler carrier gas flow rate of the most supply period in the prior art is set in the saturated carrier gas flow rate L _max. In this comparison, it is assumed that t _A ′> t _B ′, t _C ′, and that the A raw material vapor is set to L _Amax .
The bubbler carrier gas flow rate of the A raw material steam generator of the present embodiment is set to L _Amax or less. That is, L _A ≦ L _A ′
= _LAmax . Since a certain period of time is required for the transfer of the gas from the raw material vapor storage container to the reactor, the supply periods t _A , t _B , and t _C of the present embodiment have lower limits. Here, the minimum length of the supply period is uniformly defined as t _SO regardless of the type of the raw material. The actual value of t _{SO is} a value of about 1 second to 2 seconds.

In order to generally prove the effect of shortening the film forming step of the second intermittent CVD method in the present embodiment, the length λ of one cycle (= t _A + t _B + t _C + 3t _V ) and the raw material vapor The generator delivery flow rates L _A , L _B , L _C and the raw material supply periods t _A , t _B , t _C are defined by the parameters t _A ′, t _B ′, t _C ′, L _A ′, L _B ′, L _C ′ and λ _min . Here, λ _min is a minimum length λ _min = 3t _SO that can take one cycle in the present embodiment according to the above assumption.
A + 3t _V. Since the supply amount of the steam per cycle of this embodiment is the same as in the _{premise, λ × L A = t A} '× L A' ... (2) λ × L B = t B '× L _B ′ (3) λ × L _C = t _C ′ × L _C ′ (4) holds, and λ ≧ λ _min (5) must be satisfied. The film forming parameters of this embodiment are determined so as to satisfy the premise and these. The relationship between the supply period t _A ′ of the prior art A raw material steam and λ _min is
Depending on whether t _A ′> λ _min or λ _min > t _A ′, for example, the values shown in Table 1 can be taken.

[0029]

[Table 1] However, the parameter values in Table 1 are examples, and other values can be used. From the values in the table, it is found that
Calculating the ratio of the period to one period of the prior art, t _A ′> λ
_{When min}

Λ / λ ′ = t _A ′ / (t _A ′ + t _B ′ + t _C ′ + 3t _V ′) (6) When λ _min > t _A ′,

Λ / λ ′ = (3t _SO + 3t _V ′) / (t _A ′ + t _B ′ + t _C ′ + 3t _V ′) (7) Since t _SO is, by definition, the minimum value of each raw material supply period, it can be understood that in any case, the present embodiment greatly shortens one cycle of the prior art. It can be seen that the cycle shortening rate is increased as compared with the first intermittent CVD method. As a general tendency, the cycle shortening rate increases remarkably as the number of raw material systems supplied at independent timing increases. Thus, the present embodiment has an effect that the process time required for film formation can be reduced.

The third intermittent CVD method will be described with reference to FIGS. This intermittent CVD method is a method in which three types of raw material vapors A, B, and C are used and sequentially supplied to the reactor 10 in one cycle such as A → B → A → C to deposit a thin film. . Pb (Zr _x T) exemplified as the prior art
i _1-x ) When forming an O ₃ film, the third intermittent CV
Use the D method. Here, the case of three types of raw material vapors is used, but the same can be applied to the case of a combination of four or more types of raw material vapors.

The substrate 11 is housed in the reactor 10, and after the work of the pre-film formation step, the main film formation step is executed. FIG. 7 shows the flow rates L of the A raw material vapor, B raw material vapor, and C raw material vapor delivered from the raw material vapor generators 16a, 16b, and 16c and the opening and closing states of the inlet valves 17a, 17b, and 17c. It is a time chart. t _V is an evacuation period. During this period t _V , the supply of all the raw material vapor to the reactor 10 is stopped by closing the inlet valves 17a, 17b, and 17c. t
_A, t _B, t _C, respectively A feedstock vapor, B raw material vapor, C
This is a period during which the raw material vapor is supplied to the reactor 10, and the period t
_A, t _B, t _C, the corresponding inlet valve 17a, 17b,
17 c is opened, and the respective raw material vapors are supplied to the reactor 10. L = L _A , L _B , L _C are A raw material, B raw material, C raw material
The delivery flow rate of the raw material steam generators 16a, 16b, 16c is desirably set to the maximum flow rate at which at least one can be supplied stably. The origin of the time axis is B
This is the point in time when the raw material vapor generator 16b of the raw material vapor is operated to start sending out the B raw material vapor. First, the raw material steam generator 1
6b actuates the thereby sending the B material vapor at a flow rate L _B to.
Subsequently, the raw material steam generator 16a is operated after t _V + t _C , and the raw material steam generator 16c is operated after t _V + t _A + t _B. Thereafter, the raw material steam A, the raw material B, and the raw material C are always supplied to the raw material vapor storage containers 18 corresponding to the raw material lines while the inlet valves 17a, 17b, and 17c are closed.
a, 18b, and 18c. When the raw material steam generator 16b is an inlet valve 17a by a command t _A + t _C + 3t _V time after the valve control device 4 operates is opened by the time t _A, the A raw material vapor that has been stored in the raw material vapor storage container 18a A raw material vapor which is transported to the reactor 10 and simultaneously sent out from the raw material vapor generator 16a is also directly supplied to the reactor 10. The supply amount during this A raw material vapor supply period is (t
Is an _{A + t C + 2t V)} × L A. When the inlet valve 17a is closed, the reactor 10 is evacuated for the time t _V , and the A raw material vapor is completely discharged outside the reactor. At time t _V after the closing of the inlet valve 17a, the inlet valve 17b is now opened for a time t _B by a command from the valve control device 4, and the B raw material vapor and the raw material vapor temporarily stored in the raw material vapor storage container 18b. The B raw material vapor sent from the generator 16b is supplied to the reactor 10. The supply amount during the B raw material vapor supply period is (2 t
It is _{A + t B + t C +} 4t V) × L B. Inlet valve 1
When 7b is closed, the reactor 10 is evacuated for a time t _V ,
The B raw material vapor is completely discharged outside the vessel. Inlet valve 17
At time t _V after the valve b is closed, the inlet valve 17a is opened for the time t _A by a command from the valve control device 4, and the raw material vapor A and the raw material vapor generator 16a temporarily stored in the raw material vapor storage container 18a are opened. The raw material A vapor directly delivered is supplied to the reactor 10. Supply amount of the A material vapor supply period is _{(t A + t B + 2t} V) × L A. When the inlet valve 17a is closed, the reactor 10 is evacuated for the time t _V , and the raw material A vapor is completely discharged outside the reactor. At time t _V after the closing of the inlet valve 17a, the inlet valve 17c is now opened for the time t _C by a command of the valve control device 4 and the _C temporarily stored in the raw material vapor storage container 18c.
The raw material vapor and the C raw material vapor delivered from the raw material vapor generator 16c are supplied to the reactor 10. The supply amount of C material vapor supply period is _{(2t A + t B + t} C + 4t V) × L C.
When the inlet valve 17c is closed, the reactor 10 is evacuated for the time t _V , and the C raw material vapor is completely discharged outside the reactor. After the inlet valve 17c is then closed t _V time, the inlet valve 17a is opened by the time t _A by a command of the valve control device 4, supplies the A raw steam to the reactor 10. The supply amount of the A material vapor supply period is _{(t A + t C + 2t} V) × L A. When the inlet valve 17a is closed, the reactor 10 operates at time t.
Only _{V is} exhausted, and the A raw material vapor is completely discharged outside the vessel. At time t _V after closing the inlet valve 17a, the inlet valve 17b is again opened for the time t _B by the command of the valve control device 4, and the B raw material vapor is supplied to the reactor 10. The supply amount during the B raw material vapor supply period is (2t _A + t _B + t
It is a _{C + 4t V) × L B} . When the inlet valve 17b is closed, the reactor 10 is evacuated for the time t _V , and the B raw material vapor is completely discharged outside the reactor. At time t _V after the inlet valve 17b is closed, the inlet valve 17a is opened for a time t _A by a command of the valve control device 4 to supply the raw material A vapor to the reactor 10. The supply amount during the A raw material vapor supply period is (t
Is an _{A + t B + 2t V)} × L A. When the inlet valve 17a is closed, the reactor 10 is evacuated for the time t _V , and the raw material A vapor is completely discharged outside the reactor. At time t _V after the inlet valve 17a is closed, the inlet valve 17c is opened again for the time t _C by a command from the valve control device 4, and the C raw material vapor is supplied to the reactor 10. The supply amount of C material vapor supply period is _{(2t A + t B + t} C + 4t V) × L C.
When the inlet valve 17c is closed, the reactor 10 is evacuated for the time t _V , and the C raw material vapor is completely discharged outside the reactor. Hereinafter, similarly, the time λ = t _V + t _A + t _V + t _B + t
_{V + t A + t V +} t C (= 2t A + t B + t C +4
A cycle having t _V ) as one cycle is repeated a predetermined number of times, whereby a thin film having a desired thickness is grown. When the last C raw material vapor supply period is over, the process enters a post-film formation step. Thus, all the steps of the third intermittent CVD method are completed.

The effect of the third intermittent CVD method will be described. When a film is formed by the conventional CVD method in the same sequence as that shown in FIG. 7, a period between the evacuation period t _V and the supply period of the other source vapor, for example, a period between t _V + t _C + t _{V in} the case of the A source vapor. During t _V + t _B + t _V , the generated A raw material vapor was discarded by bypassing the reactor. In the third intermittent CVD method in the present embodiment, the raw material vapor during this period is A
Feedstock vapor storage containers leave temporarily stored, and taking and supplied to the reactor at the subsequent supply period t _A. For this reason,
No waste of raw material vapor can be compared to the prior art the raw material consumption is greatly reduced to _{2t A / (2t A + t} B + t C + 4t V) times. Further, in the present embodiment, since the raw material vapor is no longer abandoned, the consumption of the harm-removing agent used for processing the abandoned raw material vapor in the conventional technique can be completely reduced to zero. Further, in the third intermittent CVD method according to the present embodiment, the processing time for film formation using a liquid or a solid raw material, for which a high transport speed is difficult to obtain, can be significantly reduced. In order to clarify the effect, a description will be given by comparing the film forming main step by the third intermittent CVD method (FIG. 7) and the film forming main step by the conventional CVD method (FIG. 8) in the present embodiment. In FIG. 8, t _V ′ is the exhaust period, t _A ′, t
_B ′ and t _C ′ are supply periods of the A raw material vapor, the B raw material vapor, and the C raw material vapor. L _A ′, L _B ′, and L _C ′ are the delivery flow rates of the source A vapor, the source B vapor, and the source C vapor. To make a fair comparison, we make the following assumptions: ,
About in the first intermittent CVD method,
, The same as the premise. Bubbler carrier gas flow rate of up supply period starting material in the prior art is set in the saturated carrier gas flow rate L _max. t _A ′> t _B ′ and t
_{When A} ′> t _C ′, the A raw material vapor reaches L _Amax and t _B ′> t
_{When A} ′ or t _C ′> t _A ′, the A raw material vapor is set to L _Bmax or L _Cmax . The bubbler carrier gas flow rate of the raw material steam generator according to the present embodiment is set to L _Amax or less. The lower limits are set for the supply periods t _A , t _B , and t _C in the present embodiment. Here, all the raw material vapors are defined as t _SO regardless of the type of the raw material. The actual value of t _{SO is} a value of about 1 second to 2 seconds.

In order to generally show the effect of shortening the film forming step of the third intermittent CVD method in this embodiment, the length λ of one cycle of this embodiment (= 2t _A + t _B + t _C +4)
t _V) as the raw material steam generator delivery rate L _A, L _B, L _C and duration of the feed period t _A, t _B, the parameter t _A of t _C of the prior art (FIG. _{8) ', t B',} t C ', L _A ', L _B ', L
_C ′ and λ _min . Here, λ _min is a minimum length λ _min that can take one cycle of the present embodiment according to the above assumption.
= 4t _SO + 4t _V. Since the supply amount of the steam per cycle of the supply amount and the prior art the steam per cycle of this embodiment is the same as in the _{premise, λ × L A = 2t A} '× L A' be a _{... (8) λ × L B} = t B '× L B' ... (9) λ × L C = t C '× L C' ... (10) is _{satisfied, λ ≧ λ min ... (11} ) Must. To satisfy the assumptions and these,
As an example, each film forming parameter of the present embodiment is determined as follows. When t _A ′> t _B ′ and t _A ′> t _C ′, the total supply period 2 t _A ′ of the A raw material vapor of the prior art and λ
Depending on whether the relation of _min is 2t _A ′> λ _min or λ _min > 2t _A ′, values can be taken as shown in Table 2 depending on the case.

When t _A ′> t _B ′ and t _A ′> t _C ′

[Table 2] On the other hand, when t _B ′> t _A ′ or t _C ′> t _A ′, the total supply period 2 of the prior art B raw material vapor (or C raw material vapor) is 2
The relation between t _A ′ and λ _min is t _B ′ (or t _C ′)> λ
Depending on whether _min or λ _min > t _B ′ (or t _C ′), values as shown in Table 3 can be taken as an example.

When t _B ′> t _A ′ or t _C ′> t _A ′

[Table 3] However, the above parameter values are merely examples, and other values can be used. L _A , L _B , L _C , t _A , t _B , t
The values of _C are all smaller than those of the prior art. When the ratio of one cycle of the present embodiment to one cycle of the prior art is calculated using the values of λ in Tables 2 and 3, t _A ′> t _B ′ and t
_{When A} ′> t _C ′ and 2t _A ′> λ _min ,

Equation 4] _{λ / λ '= 2t A'} / (2t A '+ t B' + t C '+ 4t V') ... (12) in the same case as the above case of λ _min ≧ 2t _A ',

Equation 5] _{λ / λ '= (4t SO} + 4t V') / (2t A '+ t B' + t C '+ 4t V') ... (13) t B '> t A' or t _C '> t _A' 2t _A ′>
At λ _min ,

Λ / λ ′ = t _B ′ / (2t _A ′ + t _B ′ + t _C ′ + 4t _V ′) (14) In the same case as above, when λ _min ≧ 2t _A ′,

Equation 7] _{λ / λ '= (4t SO} + 4t V' _{becomes) / (2t A '+ t} B' + t C '+ 4t V') ... (15). Since t _SO is the minimum value of each raw material supply period by definition, it is understood that the present embodiment greatly shortens one cycle of the prior art in any case. The first intermittent C
It can be seen that the period shortening rate is increased as compared with the VD method. Thus, the present embodiment has an effect that the process time required for film formation can be reduced.

In the prior art shown in FIG. 14, the main steps of film formation can be greatly reduced by employing this embodiment. According to the definition of the present embodiment, the value of each parameter in FIG.
t _V ′ = 2 seconds, t _A ′ = 8 seconds, t _B ′ = 5 seconds, t _C ′ =
5 seconds and t _SO = 2 seconds, λ _min ≧ 2t in Table 2
_This corresponds to the case of _A '. If you assign a numerical value, λ = λ _{mi n}
= 16 seconds. By adopting this embodiment,
It can be seen that the film forming process of the prior art (λ ′ = 34 seconds) can be reduced to half or less. When this embodiment is adopted, the flow rates of continuously supplied oxygen and nitrogen are λ /
It is desirable to set λ ′ = about 2.1 times. Thus, even if the flow rates of oxygen and nitrogen are increased, the time of the film formation main process is λ.
/ Λ ', the consumption of both gases does not increase.

FIG. 9 shows a second embodiment of the present invention. In the present embodiment, the reactor is a hot wall type. In the figure, reference numeral 40 denotes a hot-wall type reactor, which comprises a sealed quartz tube 41 and a cylindrical electric furnace 42 surrounding the quartz tube 41 and heating at a predetermined temperature Tg. During film formation, the substrate 11 is placed inside the quartz tube 41.
A susceptor (or boat) 45 for supporting the cradle is placed. At one end of the quartz tube 41, a vapor inlet 4 for introducing one or more raw material vapors (A, B, C,...) Used for film formation.
3 is provided, and the other end is provided with an exhaust port 44 for discharging generated gas and unreacted reaction vapor to the outside of the device.
The other parts are substantially the same in configuration and function as those in FIG. 1, and thus are denoted by the same reference numerals and description thereof will be omitted.

The CVD apparatus of this embodiment can perform all of the first to third intermittent CVD methods in the first embodiment. In the execution of these CVD methods, when a raw material vapor that is coagulable at room temperature is used, the raw material vapor is prevented from aggregating on the inner wall of the reactor 40, and the effect of reliably promoting film formation can be obtained. is there.

FIGS. 10 to 12 show a third embodiment of the present invention. This embodiment simplifies the configuration of the raw material vapor supply system when a plurality of raw material vapors are intermittently supplied to the reactor at the same timing. First, the configuration of the CVD apparatus will be described with reference to FIG. In the example shown in the figure, the B raw material vapor and the C raw material vapor are intermittently supplied to the reactor 10 at the same timing. FIG. 1
The parts denoted by the same reference numerals are the same, and here, only the different parts will be described. The B raw material vapor and the C raw material vapor that have passed through the two differential pressure generators 19b and 19c merge and are introduced into the reactor 10 via a common inlet valve 17bc. Reference numeral 18bc denotes a raw material vapor storage container for temporarily storing a mixed vapor of the B and C raw materials transported from the raw material vapor generators 16b and 16c when the inlet valve 17bc is closed. The raw material vapor stored in the raw material vapor storage container 18bc is supplied to the inlet valve 17b by a command from the valve control device 4.
When c is opened, it is sent to the reactor 10 within a short time.

Comparing the raw material supply systems of this embodiment with the first embodiment (FIG. 1) or the second embodiment (FIG. 9), the present embodiment shows that the inlet valve and the raw material vapor storage The containers are simplified one by one. Such simplification is similarly effective in a system in which two or more kinds of raw material vapors are simultaneously intermittently introduced. In a system in which n raw material vapors are simultaneously supplied, it is possible to reduce the number of n-1 inlet valves and raw material vapor storage containers.

Next, the intermittent CVD method using the above-configured CVD apparatus will be described with reference to FIGS. This intermittent CVD method comprises three types of raw material vapors A, B,
Among C, B and C are supplied at the same timing (hereinafter, B
+ C) and A and B + C are alternately supplied to the reactor 10 to deposit a thin film. Here, the case of three types of raw material vapor is used, but the same can be applied to the case of four or more types of raw material vapor.

The substrate 11 is housed in the reactor 10, and after the work of the film forming pre-process, the film forming main process is executed. FIG. 11 is a time chart of the flow rates L of the raw material vapors A, B, and C transmitted from the raw material vapor generators 16a, 16b, 16c and the opening and closing states of the inlet valves 17a, 17bc during the main film forming process. It is. t _V is an exhaust period. During this period t _V , the inlet valves 17a and 17bc are closed and the reactor 1
The supply of all raw material vapors to 0 is stopped. t _A , t
_{B + C} is the supply period of each A feedstock vapor, B raw material vapor, into the reactor 10 of the C material vapor, the period t _A,
At t _{B + C} , the corresponding inlet valves 17a and 17bc are opened, and the respective raw material vapors are supplied to the reactor 10. L =
L _A , L _B , and L _C are the delivery flow rates of the raw material steam generators 16a, 16b, and 16c for the raw material A, the raw material B, and the raw material C, and at least one of them is set to the maximum flow that can be stably supplied. It is desirable. The origin of the time axis is the time when the first raw material steam generator 16a for the raw material A operates and starts to supply the raw material A vapor. First, the raw material vapor generator 16a is operated to discharge the raw material vapor _A at the flow rate LA. Subsequently, the raw material steam generators 16b and 16c are operated after t _{B + C} + t _V. Thereafter, the raw material vapors A, B and C are continuously supplied to the raw material vapor storage containers 18 corresponding to the respective raw material lines while the inlet valves 17a and 17bc are closed.
a, temporarily stored at 18bc. Raw material steam generator 16a
T _{B + C} + the 2t _V time after the inlet valve 17a in the command of the valve control unit 4 is opened by the time t _A, the reactor in a short period of time A raw material vapor that has been stored in the raw material vapor storage container 18a from but operating 10 and at the same time, the raw material A vapor delivered from the raw material vapor generator 16a is also supplied to the reactor 10
Supplied directly to Supply amount of the A material vapor supply period is _{(t A + t B + C} + 2t V) × L A. Inlet valve 1
When 7a is closed, the reactor 10 is evacuated for a time t _V ,
A Raw material vapor is completely discharged outside the vessel. Raw material steam generator 1
6b and 16c t from is actuated _{A + t B + C + 2t} V time after (or from inlet valve 17a is closed time t _V
After this, the inlet valve 17bc is opened for a time t _{B + C} by a command from the valve control device 4 and sent out from the A + B raw material vapor and the raw material vapor generators 16b, 16c temporarily stored in the raw material vapor storage container 18bc. B raw material steam and C
The raw material vapor is supplied to the reactor 10. The supply amount during the B + C raw material vapor supply period is (t _A + t _{B + C} + 2t _V ) × (L _B + L
_C ). When the inlet valve 17bc is closed, the reactor 1
0 is exhausted for the time t _V , and the A + B raw material vapor is completely exhausted outside the vessel. T after the inlet valve 17bc is closed
After time _V , the inlet valve 17a is again opened for the time t _A by a command from the valve control device 4, and the raw material vapor storage container 1 is opened.
A raw material vapor temporarily stored in 8a and A raw material vapor directly sent from the raw material vapor generator 16a are supplied to the reactor 10. The supply amount during the A raw material vapor supply period is (t _A + t
_B is a _{+ C + 2t V) × L} A. When the inlet valve 17a is closed, the reactor 10 is evacuated for the time t _V , and the raw material A vapor is completely discharged outside the reactor. Similarly, the inlet valve 17a
At time t _V after the valve is closed, the inlet valve 17bc is opened again for the time t _{B + C} again by a command from the valve control device 4, and A temporarily stored in the raw material vapor storage container 18bc.
The + B raw material vapor and the B raw material vapor and the C raw material vapor sent from the raw material vapor generators 16b and 16c are supplied to the reactor 10. The supply amount during the B + C raw material vapor supply period is (t _A + t _{B + C}
+ 2t _V ) × (L _B + L _C ). Inlet valve 17b
When c is closed, the reactor 10 is evacuated for a time t _V and A
+ B raw material vapor is completely discharged outside the vessel. Hereinafter, similarly, the time λ = t _A + t _V + t _{B + C} + t _V (= t _A + t
A cycle having ( _{B + C} + 2t _V ) as one cycle is repeated a predetermined number of times, whereby a thin film having a desired film thickness is grown. After the last supply period t _{B + C} of the C raw material vapor and the B raw material vapor, a post-film formation process is started. Thus, all the steps of the intermittent CVD method in the present embodiment are completed.

Intermittent CVD in this embodiment described above
Explain the effect of the law. In the conventional CVD method, the transport amount (flow rate and vaporization rate) of the raw material vapor generator during the evacuation period t _V and the supply period of another raw material vapor, for example, the time t _{B + C} + 2t _V for the raw material vapor A. In order to stabilize), the generated A raw material vapor was discarded by bypassing the reactor.
In the intermittent CVD method of the present embodiment, the raw material vapor during this period is temporarily stored in the raw material vapor storage container _A , and is supplied to the reactor during the subsequent supply period tA. Therefore, there is no waste of raw material vapor, as compared to the prior art the raw material consumption can be greatly reduced to _{t A / (t A + t} B + C + 2t V). Further, in the present embodiment, since the raw material vapor is no longer abandoned, the consumption of the harm-removing agent used for processing the abandoned raw material vapor in the conventional technique can be completely reduced to zero. Furthermore, the intermittent CV of the present embodiment
In the method D, the time required for the main film formation step using a liquid or a solid raw material, for which a high transport speed is difficult to obtain, can be greatly reduced. In order to clarify the effect, a description will be given of a comparison between the main film forming step (FIG. 11) in the intermittent CVD method according to the present embodiment and the main film forming step (FIG. 12) in the conventional CVD method. FIG.
Here, t _V ′ is an exhaust period, t _A ′ is a supply period of A raw material vapor, and t _{B + C} ′ is a supply period of B raw material vapor and C raw material vapor. L _A ′, L _B ′, and L _C ′ are the delivery flow rates of the source A vapor, the source B vapor, and the source C vapor. To make a fair comparison, we make the following assumptions: ,..., The second intermittent C in the first embodiment.
This is the same as the premise of the VD method. Since a certain period of time is required to transfer gas from the raw material vapor storage container to the reactor, the supply period t _A ,
There is a lower limit on the length of t _{B + C.} Here, the minimum length of the supply period is uniformly defined as t _SO regardless of the type of the raw material. The actual value of t _{SO is} a value of about 1 second to 2 seconds.

In order to generally prove the effect of shortening the film forming process of the intermittent CVD method in the present embodiment, the length of one cycle λ (= t _A + t _{B + C} + 2t _V ) and the raw material steam generator The delivery flow rates L _A , L _B , L _C and the raw material supply periods t _A , t _{B + C} are defined by parameters t _A ′, t _{B + C} ′, L of the prior art (FIG. 12).
_A ′, L _B ′, L _C ′ and λ _min . Where λ
According to the above premise, _min is the minimum length λ _min = 2t _SO + 2t _V that can take one cycle of the present embodiment. Since the supply amount of the steam per cycle of this embodiment is the same as in the _{premise, λ × L A = t A} '× L A' ... (16) λ × L B = t B + C _{'× L B' ... (17} ) λ × L C = t B + C '× L C' ... (18) is satisfied, should be _{λ ≧ λ min ... (19)} . The film forming parameters of this embodiment are determined so as to satisfy the premise and these. The relationship between the supply period t _A ′ of the prior art A raw material steam and λ _min is
Depending on whether t _A ′> λ _min or λ _min > t _A ′, for example, the values shown in Table 4 can be taken.

[0045]

[Table 4] However, the parameter values in Table 4 are merely examples, and other values can be used. From the values in the table, it is found that
Calculating the ratio of the period to one period of the prior art, t _A ′> λ
_{When min}

Λ / λ ′ = t _A ′ / (t _A ′ + t _{B + C} ′ + 3t _V ′) (20) When λ _min > t _A ′,

Equation 9] _{λ / λ '= (2t SO} + 2t V' _{becomes) / (t A '+ t} B + C' + 2t V ') ... (21). Since t _SO is, by definition, the minimum value of each raw material supply period, it can be understood that in any case, the present embodiment greatly shortens one cycle of the prior art. It can be seen that the cycle shortening rate is increased as compared with the first intermittent CVD method in the first embodiment. As a general tendency, the cycle shortening rate increases remarkably as the number of raw material systems supplied at independent timing increases. Thus, the present embodiment has an effect that the process time required for film formation can be reduced.

The above-mentioned intermittent CVD method uses the first,
It can also be performed using the CVD apparatus of the second embodiment. Further, the CVD apparatus of the present embodiment can also perform the first intermittent CVD method of the first embodiment.

FIG. 13 shows a fourth embodiment of the present invention. The present embodiment further simplifies the configuration of the raw material vapor supply system when all of the plural raw material vapors are intermittently supplied to the reactor at the same timing. That is,
In the example of the third embodiment shown in FIG. 10, among the raw material vapors of A, B, and C, the raw material vapor B and the raw material C are intermittently supplied to the reactor at the same timing.
In the present embodiment, all three raw material vapors A, B, and C are intermittently supplied to the reactor at the same timing. The configuration of the CVD apparatus according to the present embodiment will be described with reference to FIG. In the example shown in the figure, three raw material vapors A, B and C are all intermittently supplied to the reactor 10 at the same timing. Three differential pressure generators 19a,
The three raw material vapors A, B and C having passed through 19b and 19c are merged and introduced into the reactor 10 through a common inlet valve 17abc. 18abc is the raw material steam generator 16a when the inlet valve 17abc is in the closed state,
This is a raw material vapor storage container for temporarily storing a mixed vapor of three raw materials A, B, and C transported from 16b and 16c.
The raw material vapor stored in the raw material vapor storage container 18abc is sent to the reactor 10 within a short time when the inlet valve 17abc is opened according to a command from the valve control device 4.

This embodiment and the third embodiment (FIG. 1)
Comparing the raw material supply system of 0), in the present embodiment, the inlet valve and the raw material vapor storage container are further simplified one by one. Further, in comparison with the raw material supply system of the first embodiment (FIG. 1) or the second embodiment (FIG. 9), in the present embodiment, the inlet valve and the raw material vapor storage container are simplified by two. Have been. In the present embodiment, along with the simplification of the apparatus configuration, when all of the plurality of raw material vapors are intermittently supplied to the reactor 10 at the same timing to form a film, the simultaneous processing of all the plurality of raw material vapors is performed. Is guaranteed, and film formation can be surely promoted.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a chemical vapor deposition apparatus according to the present invention.

FIG. 2 is a configuration diagram showing a raw material steam generator in FIG. 1 in detail.

FIG. 3 is a diagram illustrating a first intermittent CV according to the first embodiment;
6 is a timing chart for explaining a D method.

FIG. 4 is a timing chart in the related art shown as a comparative example of FIG. 3;

FIG. 5 is a diagram illustrating a second intermittent CV according to the first embodiment.
6 is a timing chart for explaining a D method.

FIG. 6 is a timing chart in the related art shown as a comparative example of FIG. 5;

FIG. 7 shows a third intermittent CV in the first embodiment.
6 is a timing chart for explaining a D method.

FIG. 8 is a timing chart in the related art shown as a comparative example of FIG. 7;

FIG. 9 is a configuration diagram showing a second embodiment of the present invention.

FIG. 10 is a configuration diagram showing a third embodiment of the present invention.

FIG. 11 is a timing chart for explaining an intermittent CVD method according to the third embodiment.

FIG. 12 is a timing chart in the related art shown as a comparative example of FIG. 11;

FIG. 13 is a configuration diagram showing a fourth embodiment of the present invention.

FIG. 14 is a view for explaining a CVD method in a conventional chemical vapor deposition apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Reactor system 2 Raw material vapor supply system 3 Vacuum exhaust system 10, 40 Reactor 11 Substrate 16a, 16b, 16c Raw material vapor generator 17a, 17b, 17c, 17bc, 17abc Inlet valve 18a, 18b, 18c, 18bc, 18abc Raw material Steam storage container 19a, 19b, 19c Differential pressure generator

Claims (5)

[Claims] A plurality of different types of chemical vapors are respectively generated by a plurality of raw material steam generators, the generated chemical vapors are transported by a transport pipe, and an inlet valve is opened and closed intermittently to generate a plurality of the chemical vapors. In a chemical vapor deposition apparatus for periodically introducing at least one kind of chemical vapor into a reactor and forming a thin film on a heating substrate provided in the reactor, the chemical vapor deposition apparatus is disposed on the transportation pipe, and the inlet When the valve is closed, temporarily store the chemical vapor generated by the corresponding raw material vapor generator,
Chemical vapor deposition comprising: a raw material vapor storage container that sends the temporarily stored chemical vapor to the reactor together with the chemical vapor generated by the raw material vapor generator when the inlet valve is opened. apparatus. 2. The raw material vapor storage container comprises a temperature control means for maintaining the raw material vapor storage container at a constant temperature equal to or higher than the re-agglomeration temperature of the chemical vapor to be stored. Chemical vapor deposition equipment. 3. A differential pressure generator for keeping the internal pressure of the raw material steam generator higher than the pressure of the raw material steam storage container on the way of the transportation between the connection point of the raw material vapor storage container and the raw material steam generator. 2. A container is provided.
A chemical vapor deposition apparatus as described. 4. The method according to claim 1, wherein at least two of the plurality of raw material steam generators share one raw material steam storage container and one inlet valve. The chemical vapor deposition apparatus according to claim 1. 5. The chemical vapor generator according to claim 1, wherein all of the plurality of raw material steam generators are configured to share one raw material vapor storage container and one inlet valve. Phase growth equipment.