JP2000223430A - Heat treatment apparatus and cleaning method thereof - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To easily remove a reaction product attached to the inside of a reaction chamber in a short time. SOLUTION: During the film forming process, the pressure in a reaction tube 11 is controlled by a combination valve CV, hydrocarbons and the like are removed by a hot disk trap TRP1, and ammonium chloride is removed by a switching trap TRP2. Next, the reaction chamber 11 and the pipe 63a are heated to 100 ° C. to 150 ° C., and the combination valve CV is used to heat the pipe 63a.
While maintaining the inside at a pressure of 10 kPa to 30 kPa, hydrogen fluoride of the gas source 35 d is supplied from the inlets 64 a to 64 c to the portions where the conductance and the temperature of the exhaust gas decrease, and the exhaust gas is washed. Also, the combination valve C
Cleaning may be performed by supplying hydrogen fluoride while changing the inside of the pipe 63a between 0.1 kPa and 30 kPa with V. Further, after completion of the cleaning, the hydrogen fluoride used for the cleaning is efficiently removed by supplying the alkoxysilane for a predetermined time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment apparatus and a cleaning method thereof, and more particularly, to a heat treatment apparatus and a cleaning method thereof capable of preventing reaction products from adhering to the inside of the apparatus.

[0002]

2. Description of the Related Art In general, a vertical heat treatment apparatus reacts a cylindrical reaction tube (reactor) made of quartz or the like, a heater, and a semiconductor substrate (wafer) as an object to be processed mounted on a wafer boat. A loading mechanism for loading into the tube and unloading the processed wafer boat from within the reaction tube;
A gas supply pipe for supplying a processing gas into the reaction tube and an exhaust pipe for exhausting gas in the reaction pipe are provided.

A semiconductor substrate to be processed is placed on a wafer boat and loaded into a reaction tube. A processing gas is supplied to the reaction tube under heating, and the semiconductor substrate and the processing gas react with each other or the processing gases are separated from each other. In response, a film forming process is performed on the surface of the semiconductor substrate. After the film forming process, the wafer board is unloaded from the reaction tube, the semiconductor substrate is pulled out from the wafer boat, and the semiconductor substrate is transported to the next step.

However, in the film forming process performed in the vertical heat treatment apparatus, a reaction by-product is generated. The generated reaction by-products are adsorbed on the semiconductor substrate, which is one of the causes of particle generation. For example, a silicon nitride film (Si
₃ During formation of the N ₄ film), ammonium chloride _(NH 4 C
l) solidifies at a low temperature in the reaction tube. When the ammonium chloride sublimes during the loading of the semiconductor substrate and is adsorbed on the semiconductor substrate, in the subsequent film forming process, the ammonium chloride becomes a seed and particles may be formed on the substrate surface. In addition, particles formed by the reaction between sublimed ammonium chloride and moisture in the atmosphere may be adsorbed to the semiconductor substrate to cause defects. Therefore, it may be difficult to manufacture a high-quality semiconductor device at a high yield rate.

[0005] In order to reduce this problem, it is necessary to remove the reaction products in the reaction tube and the exhaust pipe in the configuration of the vertical heat treatment apparatus. For this reason, conventionally, by providing a disk trap or a water trap in the flow path of the exhaust gas,
The reaction products in the exhaust gas were removed.

The disk trap has, for example, a structure in which a large number of disk-shaped members (disks) are arranged in the flow path. As a result, exhaust gas flowing in the flow path having reduced conductance comes into contact with the disk. The reaction by-products are deposited on the disk of (1), and the reaction products are removed from the exhaust gas.

The water trap has a structure in which a water-cooled cooling pipe or the like is arranged in a flow path. Exhaust gas flowing in the flow path exchanges heat with the cooling pipe or the like, and as a result, a reaction is generated on the cooling pipe. By-products are precipitated, thereby removing the products from the exhaust gas.

[0008]

However, even if by-products are removed by a trap or the like, it is inevitable that reaction products (main products and by-products) adhere to the heat treatment apparatus. In particular, a large amount of reaction products adhere to the vicinity of the manifold section and the exhaust section of the reaction tube and the exhaust pipe since the temperature is lower and the exhaust conductance is lower than the film formation processing area where the wafer boat is disposed. Would.

The adhering reaction products become particles during the loading and unloading into the reaction tube of the wafer boat, and are adsorbed on the semiconductor substrate, or the adsorbed products generate new particles with the nuclei.
Therefore, in the conventional vertical heat treatment apparatus, it is necessary to clean every predetermined period to remove the deposits. Conventionally, for cleaning, large-scale maintenance involving a long-term stoppage of operation is required, such as disassembling the apparatus and wet-cleaning each component using a hydrofluoric acid (HF) acid solution. For this reason, the operation rate of the device has been reduced.

The present invention has been made in view of the above circumstances, and can easily remove reaction products adhered to the inside in a short time, thereby preventing the reaction products from adhering in the exhaust gas flow path. It is an object of the present invention to provide a heat treatment apparatus and a cleaning method thereof.

[0011]

In order to achieve the above object, a heat treatment apparatus according to a first aspect of the present invention comprises a reaction chamber capable of storing an object to be processed and an exhaust pipe connected to the reaction chamber. Exhaust pipe for exhausting gas in the reaction chamber, and HF connected to a hydrogen fluoride gas source.
A HF valve installed in the HF pipe to control the supply of hydrogen fluoride gas from the gas source; and supplying hydrogen fluoride supplied from the gas source through the HF pipe into the exhaust pipe. And / or an HF gas supply unit having an inlet leading into the reaction chamber, a heating unit for heating the exhaust pipe, and a pressure control unit for controlling a pressure in the exhaust pipe.

According to the heat treatment apparatus having this configuration, the reaction products (including by-products) attached to the inside of the reaction chamber and the exhaust pipe are easily removed in a short time by the hydrogen fluoride supplied by the HF gas supply means. Is done. Also, during cleaning with HF gas,
The heating means heats the exhaust pipe to be cleaned and the pressure control means controls the pressure in the exhaust pipe, so that cleaning can be performed appropriately.

When the exhaust pipe has a bent portion, it is preferable that the inlet is disposed near the bent portion of the exhaust pipe and upstream of the flow path as viewed from the reaction chamber. As a result, the places where reaction products are particularly likely to adhere due to a decrease in the temperature of the exhaust gas or a decrease in the conductance are mainly washed, the efficiency of the washing is improved, and the operation of the heat treatment apparatus becomes more efficient. .

[0014] A trap means for removing a reaction product in the exhaust pipe may be provided in the exhaust pipe. A plurality of the trap means may be arranged according to the material of the film formation target. The pressure control means is disposed between the plurality of traps in consideration of the type and characteristics of a reaction by-product.
In this case, it is desirable that the inlet is disposed near the trap of the exhaust pipe and upstream of the flow path viewed from the reaction chamber.

[0015] The reaction chamber is, for example, an apparatus for forming a silicon oxide film on the object by decomposition of alkoxysilane and / or forming a silicon nitride film on the object by reaction of ammonia and dichlorosilane. It is composed of

The pressure control means maintains the pressure in the exhaust pipe constant, for example, by adjusting the degree of opening of the exhaust pipe. Such a configuration can be realized, for example, by detecting the pressure in the exhaust pipe and automatically controlling the opening degree of the valve based on a deviation between the detected pressure and a set pressure. The pressure control means simplifies the structure of the exhaust pipe, and prevents a place where reaction products are particularly likely to adhere due to a decrease in the temperature of the exhaust gas or a decrease in conductance.

The pressure control means may control the partial pressure of hydrogen fluoride in the exhaust pipe by, for example, 10 k
It is maintained at Pa or more.

[0018] Further, a temperature raising means for raising the temperature of the reaction chamber is provided, and the heating means sets the exhaust pipe at 100 ° C to 200 ° C.
C., and the pressure control means
The pressure may be maintained at kPa to 30 kPa. Under such conditions, cleaning can be performed efficiently.

On the other hand, the pressure control means may include means for changing a pressure of a hydrogen fluoride atmosphere in the exhaust pipe. As a result, the hydrogen fluoride gas easily permeates (attains) into a portion having a low conductance such as an uneven portion, so that cleaning can be performed more efficiently and corrosion of the material can be prevented.

In this case, the pressure control means may be, for example,
The pressure in the exhaust pipe is varied between 0.1 kPa and 30 kPa. Further, the pressure control means varies the pressure in the exhaust pipe so that a period in which the pressure in the exhaust pipe is equal to or higher than 10 kPa and a period in which the pressure in the exhaust pipe is lower than 10 kPa are repeated. Hydrogen fluoride exerts a cleaning action when the pressure is 10 kPa, so that the period in which the pressure is 10 kPa or more is longer than the period in which the pressure is less than 10 kPa,
It is desirable to vary the pressure.

The hydrogen fluoride used for the cleaning must be finally discharged out of the heat treatment apparatus. In order to perform this discharge process efficiently in a short time, the inside of the exhaust pipe and / or
Or a film forming gas supply unit for supplying a film forming gas into the reaction chamber, and into the exhaust pipe and / or into the reaction chamber.
After the purge gas supply means for supplying the purge gas and the HF gas supply means stop supplying hydrogen fluoride,
The supply and exhaust of the purge gas into and from the exhaust pipe and / or the reaction chamber are repeated a plurality of cycles by the purge gas supply unit and the exhaust unit, and the film formation gas supply is performed during the plurality of cycles. And a control means for supplying a film-forming gas by means. By supplying the deposition gas between the supply and the exhaust of the purge gas, the hydrogen fluoride is easily exhausted, and the hydrogen fluoride can be efficiently exhausted in a short time.

The film forming gas supply means is desirably the same as the film forming gas to be formed (formed) by this heat treatment apparatus. According to this configuration, hydrogen fluoride can be efficiently exhausted using the original film forming gas without disposing a special exhaust device.

The film forming gas supply means supplies, for example, alkoxysilane (preferably tetraethoxysilane) which is a raw material of a silicon oxide film as a film forming gas, and the purge gas supply means, for example, nitrogen gas as a purge gas. Supply.

A cleaning method according to a second aspect of the present invention is a cleaning method for cleaning at least one of a reaction chamber of a heat treatment apparatus and an exhaust pipe connected to the reaction chamber. Cleaning by heating at least one of the tubes and supplying hydrogen fluoride gas to at least one of the reaction chamber and the exhaust tube while evacuating while maintaining the pressure of the exhaust tube constant. I do. According to this cleaning method, the reaction products (main products and by-products) attached to the reaction chamber and the exhaust pipe are easily removed in a short time by the hydrogen fluoride.

For cleaning, for example, the pressure of the exhaust pipe is set to 10 kP.
This is performed by supplying hydrogen fluoride gas to at least one of the reaction chamber and the exhaust pipe while maintaining the value of a or more. In this case, the temperature of the reaction chamber was raised, and the exhaust pipe was heated to 100 ° C to 200 ° C.
And the pressure in the exhaust pipe is increased from 10 kPa to 30 kP.
By maintaining at a, cleaning can be performed efficiently.

A cleaning method according to a third aspect of the present invention is a cleaning method for cleaning at least one of a reaction chamber of a heat treatment apparatus and an exhaust pipe connected to the reaction chamber. At least one of the tubes is heated, and while varying the pressure in the exhaust pipe, hydrogen fluoride gas is supplied to at least one of the reaction chamber and the exhaust pipe to perform cleaning.
It is characterized by the following. According to this cleaning method, the hydrogen fluoride gas easily penetrates into a portion where the conductance is low, and cleaning can be performed efficiently.

The cleaning is performed, for example, by reducing the pressure in the exhaust pipe to 0.1.
This is performed by supplying hydrogen fluoride gas to the reaction chamber and the exhaust pipe while changing the pressure between kPa and 30 kPa. Further, the pressure in the exhaust pipe is changed so that a period in which the pressure in the exhaust pipe is 10 kPa or more and a period in which the pressure in the exhaust pipe is less than 10 kPa are repeated. Hydrogen fluoride exerts a cleaning action when its pressure is 10 kPa. Therefore, it is desirable to change the pressure so that a period in which the pressure is 10 kPa or more is longer than a period in which the pressure is less than 10 kPa.

In the invention according to the second and third aspects, before cleaning, a silicon oxide film is formed on the object by decomposition of alkoxysilane and / or a reaction of ammonia and dichlorosilane forms the object. After the silicon nitride film is formed thereon, the object to be processed is taken out of the reaction chamber after the formation, and after the object to be processed is taken out, hydrogen fluoride gas is supplied to wash the reaction chamber and the exhaust pipe. Good.

At a plurality of locations in the exhaust pipe, impurities in the exhaust gas are removed by traps, and the pressure of the hydrogen fluoride gas is controlled by controlling the degree of opening of the exhaust pipe between the plurality of traps. You may do so.

In order to efficiently discharge the hydrogen fluoride used for cleaning, the supply of hydrogen fluoride gas is stopped, the pressure in the exhaust pipe is reduced, and the supply of purge gas and the pressure in the exhaust pipe are performed a predetermined number of times. Alternatively, a film forming gas may be supplied to at least one of the reaction chamber and the exhaust pipe, and the supply of the purge gas and the pressure reduction in the exhaust pipe may be repeated a predetermined number of times. By employing this removal method, the hydrogen fluoride gas used for cleaning can be removed in a short time.

The purge gas is composed of, for example, nitrogen gas, and the film forming gas is composed of alkoxysilane (for example,
(Tetraethoxysilane).

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a configuration of a vertical heat treatment apparatus according to a first embodiment of the present invention. This vertical heat treatment apparatus is shown in FIG.
As shown in FIG. 1, a cylindrical reaction tube (reaction chamber) 11 whose longitudinal direction is directed vertically is provided. The reaction tube 11 includes an outer cylinder 12 having a lower end opening made of a heat-resistant material, for example, quartz,
It has a double-pipe structure comprising an outer cylinder 12 and an inner cylinder 13 with upper and lower openings that are concentrically housed and separated from the inner wall of the outer cylinder 12 as appropriate.

A wafer boat (heat treatment boat) 14 made of quartz or the like is provided in the reaction tube 11. In the wafer boat 14, semiconductor substrates (semiconductor wafers) 15 as objects to be processed are stacked and housed at predetermined intervals in the vertical direction.

At the periphery of the reaction tube 11, there is provided a temperature increasing heater 16 formed of a resistance heating element or the like formed so as to surround the reaction tube 11.

Below the outer cylinder 12 and the inner cylinder 13, an outer cylinder 1 is provided.
A stainless steel manifold 17 that supports the inner cylinder 2 and the inner cylinder 13 is provided. A flange 18 is formed in an annular shape at the upper end of the manifold 17, and is configured to be hermetically sealed via a flange 19 formed at a lower end of the outer cylinder 12 and an O-ring 20 made of an elastic member. ing. The lower end of the inner cylinder 13 is placed on a support 21 formed to protrude inward from the inner wall of the manifold 17.

On one side surface of the manifold 17, there are first and second made of quartz or the like bent toward the heat treatment section (upward).
Third gas supply pipes 31a, 31b and 31c are inserted through seal members.

The first gas supply pipe 31a has a joint 32
The first gas pipe 33a is connected via a. The first gas pipe 33a is connected to a first gas source 35a via a mass flow controller (MFC) 34a for adjusting a gas flow rate and a valve VB1 for controlling a gas flow. The first gas source 35a is, for example, a gas source of dichlorosilane (SiH ₂ Cl ₂ ). The first gas pipe 33a is also connected to the nitrogen gas source 36a via the MFC 34a and the valve VB3.

The second gas supply pipe 31b has a joint 32
The second gas pipe 33b is connected via b. The second gas pipe 33b is connected to a second gas source 35b via a mass flow controller (MFC) 34b for adjusting a gas flow rate and a valve VB2 for controlling a gas flow. The second gas source 35b includes, for example, ammonia (NH
₃ ) The gas source. The second gas pipe 33b is
Nitrogen gas source 36b via MFC 34b and valve VB4
Is also connected.

The third gas supply pipe 31c has a joint 32
The third gas pipe 33c is connected via the “c”. The third gas pipe 33c is connected to the third gas source 35c via the MFC 34c and the valve VB5. The third gas source 35c is, for example, an alkoxysilane, desirably,
It is a gas source of tetraethoxysilane (hereinafter simply referred to as TEOS).

A disc-shaped lid 51 is provided on the flange 22 formed at the lower end of the manifold 17 so as to be hermetically sealed via an O-ring 52 made of an elastic member.
A heat insulating cylinder 53 is disposed on the upper surface of the lid 51, and the heat insulating cylinder 53 is provided.
A wafer boat 14 is placed on the table. Lid 51
Is mounted on an elevating mechanism 54 that moves vertically to load and unload (load / unload) the heat retaining cylinder 53 and the wafer boat 14 placed on the lid 51 to and from the reaction tube 11.

An inlet 64a for guiding cleaning hydrogen fluoride (HF) into the reaction tube 11 is connected to a lower end portion of the manifold 17, and the inlet 64a is connected to a fourth gas pipe 33d and a valve VB6. Is connected to a fourth gas source 35d which is a gas source of hydrogen fluoride. The fourth gas source 35d is also connected to an inlet 64b described later via a valve VB6 and a fifth gas pipe 33e, and is connected to an inlet described later via a valve VB6 and a sixth gas pipe 33f. 64c.

An exhaust pipe 61 is connected to the other side of the manifold 17. The exhaust pipe 61 is made of stainless steel or the like, and is connected via a joint 62 to an exhaust pipe 63 for exhausting exhaust gas to the outside.

The exhaust pipe 63 has pipes 63a to 63c. The pipe 63a is connected to the exhaust pipe 61 via the joint 62, and guides exhaust gas from the reaction pipe 11 to the pipe 63b. The pipe 63b guides the exhaust gas from the hot disk trap TRP1 to the suction port of the vacuum pump VP via the combination valve CV and the switching trap TRP2 sequentially. One end of the pipe 63c is connected to the exhaust port of the vacuum pump VP, and the other end is branched into two. In addition, piping 6
A factory exhaust pipe 63d that guides exhaust gas passing through the pipe 63a to so-called factory exhaust is connected to a predetermined position of 3a. An open / close factory exhaust valve EV and a damper (not shown) are disposed in the factory exhaust pipe 63d. Further, this vertical heat treatment apparatus includes an exhaust path heater 6 for heating the pipe 63a and the combination valve CV.
5 is provided.

The pipe 63a has a bent portion, and an inlet 64b for leading hydrogen fluoride into the pipe 63a is connected near the upstream of the bent portion as described above. The inlet 64b is connected to the fifth gas pipe 33e and the valve V
It is connected to the fourth gas source 35d via B6.

An inlet 64c for introducing hydrogen fluoride into the hot disk trap TRP1 is connected near the upstream side of the gas inlet of the hot disk trap TRP1 in the pipe 63a. Inlet 64c
As described above, the sixth gas pipe 33f and the valve V
It is connected to the fourth gas source 35d via B6.

The hot disk trap TRP1 has a TE
It adsorbs hydrocarbons and the like, which are products generated when OS ₂ is produced from the OS. For example, a housing having gas inlets and gas outlets at both ends where exhaust gas flows in and out, and this housing A disk assembly and a cover housed therein; and a heater. The gas inlet is connected to the pipe 63a, and the gas outlet is connected to the combination valve CV via the pipe 63b.
It is connected to the.

The disk assembly has a cylindrical shape with both ends open, and a plurality of disks made of a disk-shaped adsorbent having an opening, for example, are placed in a gas inlet through a gas outlet while facing each other. It is held so as to form a line at predetermined intervals toward. The open end of the disk assembly on the side desired for the gas inlet is closed by a cover. The heater heats the disk to prevent NH ₄ Cl from adhering to the disk held by the disk assembly, and may be configured to surround the periphery of the housing. It may be provided inside.

The gas flowing from the gas inlet flows into the gap between the disk assembly and the inner wall of the housing.
The gas flows into the space inside the disk assembly through the gap between the disks held by the disk assembly, and then is discharged from the gas outlet. TEOS
Hydrocarbons C _x H _y (x and y are natural numbers) and the like, which are reaction by-products generated when SiO ₂ is produced from the gas, are discharged to each disk when the exhaust gas passes through a gap between the disks. Adsorbed.

The switching trap TRP2 is used for detecting the N 2 in the exhaust gas.
It is for adsorbing H ₄ Cl, and includes a plurality of water-cooled traps arranged in parallel and for adsorbing NH ₄ Cl in the exhaust gas passing therethrough, a switching unit, and a cleaning chamber.

Each water-cooled tiger included in the switching trap TRP2
The gas inlet and the gas inlet and outlet for exhaust gas
A housing having a discharge port and disposed within the housing
Cooling section and the inflow / outflow section of cooling water circulating in the cooling section
It has. Cooling part is cooling water cooled by cooling water
Circulation unit and multiple cooling units provided on the surface of cooling water circulation unit
With fins. Gas flowing from gas inlet
Hits the cooling part and is cooled by contacting the cooling fins.
Substances which can be attached by cooling, such as
Silicon nitride film by the reaction of near and dichlorosilane
Ammonium chloride, a by-product of the reaction
Um NH₄Cl precipitates on the cooling section, which causes exhaust gas
From NH ₄Cl is removed. NH₄Cl is removed
Exhaust gas is discharged from the gas outlet to the vacuum pump VP.
It is.

One of the switching traps TRP2 is
When the exhaust gas is passing, the switching unit is operated by the operator.
So that the exhaust gas passes through other traps
And then the one from which the exhaust gas has passed
The exhaust gas flowing to the wrap is shut off and the trap is cleaned.
Connect to room. Then, the water stored in the washing room,
It is pressurized by the pump provided in the cleaning chamber and connected to the cleaning chamber.
Into the trap. The incoming water is trapped in this trap
Collected by NH₄Wash off the Cl and return to the washing room to wash
It is drained from the chamber and fresh water is stored in the washing room. This
By repeating such a procedure, the switching trap TR
Each trap of P2 is any other trap
Is cleaned while passing exhaust gas, thus switching
The trap TRP2 allows exhaust gas to pass through without interruption and exhaust
NH in gas ₄Adsorb Cl.

The combination valve CV is connected to the reaction tube 1
It is provided to perform exhaust while automatically controlling the pressure in the inside 1. The combination valve CV includes a valve,
A valve control unit and a pressure detection unit are provided. The pressure detection unit detects the pressure in the pipes 63a and 63b and notifies the valve control unit, and the valve control unit adjusts the opening degree of the valve so that the pressure notified by the pressure detection unit converges to a predetermined value. By doing so, the flow rate of exhaust gas flowing from the hot disk trap TRP1 to the switching trap TRP2 is controlled.

By such an operation, the combination valve CV can increase the pressure in the pipes 63a and 63b to an arbitrary value substantially in the range of 0 to 1013 hPa without using another valve or the like arranged in parallel with itself. Adjust to value and maintain. Therefore, the mechanism for opening and closing the flow path of the exhaust gas is simply configured by using the combination valve CV, and is complicated and includes a plurality of valves and a pipe for guiding the exhaust gas to the plurality of valves in parallel. Moreover, a configuration that causes a decrease in the conductance of the flow path becomes unnecessary. As a result, a portion where the conductance is reduced is prevented from being formed in the flow path of the exhaust gas, and an increase in locations where products generated during a film forming process described later are attached is suppressed.

The vacuum pump VP has an intake port and an exhaust port, and has an exhaust capacity of about 15,000 to 20,000 liters / minute. The exhaust port of the vacuum pump VP is connected to one end of the pipe 63c. The other end of the pipe 63c is branched into two, one of which forms a first exhaust port for exhausting an exhaust gas when generating the silicon oxide film SiO ₂ and the silicon nitride film Si ₃ N _4. The other forms a second exhaust port for discharging the hydrogen fluoride gas used for cleaning.
The pipe 63c is provided with a valve 69, and the exhaust gas discharged from the vacuum pump VP is discharged from the first or second exhaust port which is selected by switching the valve 69.

Next, the operation of this vertical heat treatment apparatus is described in a case where a silicon oxide film SiO ₂ and a silicon nitride film Si ₃ N ₄ are formed, and after the film formation processing is completed, the inside of the vertical heat treatment apparatus is cleaned. Will be described as an example.

The heating heater 16, the mass flow controllers 34a to 34c, the combination valve C
V, gas sources 35a to 35d, 36a, 36b, valve V
B1 to VB6, the elevating mechanism 54, the vacuum pump VP, and the exhaust path heater 65 are connected to a controller (not shown) for controlling them. The controller measures the temperature, pressure, and the like of each part of the vertical heat treatment apparatus using a sensor (not shown), and automatically controls a series of processes described below by supplying a control signal or the like to each part.

First, as shown in FIG. 2, in a state where the elevating mechanism 54 is lowered, the wafer boat 14 on which the semiconductor substrate 15 is mounted is mounted on the heat insulating cylinder 53 on the lid 51. You. At this time, the heating heater 16 is set to about 700
Heat to between 800C and 800C. Next, the lifting mechanism 54 is raised to move the lid 51 and the wafer boat 14 upward, thereby loading the wafer boat 14 into the reaction tube 11. At this time, while the factory exhaust valve EV is closed, the vacuum pump VP is driven and the opening of the combination valve CV is controlled, so that a pressure difference of about -500 Pa with respect to the pressure (atmospheric pressure) in the reaction tube 11 is obtained. Reaction tube 11
The wafer boat 14 is loaded while sucking the gas inside. As a result, as schematically shown in FIG.
1 is sucked to prevent the particles from adhering to the semiconductor substrate 15.

When the loading of the wafer boat 14 into the reaction tube 11 is completed and the flange 22 and the lid 51 formed at the lower end of the manifold 17 reach an airtight state via the O-ring 52, the combination valve CV is opened. The opening degree is controlled to slow the exhaust (that is, the semiconductor substrate 15 to be processed).
Of the reaction tube 11 and evacuation at an evacuation speed such that the reaction product is not wound up in the reaction tube 11), and the pressure inside the reaction tube 11 is reduced to a predetermined pressure, for example, 0.5 to 0.7 Pa.

When the pressure in the reaction tube 11 reaches a predetermined value,
By opening the valves VB1 and VB2, NH ₃ is supplied from the first gas source 35a and SiH ₂ Cl ₂ is supplied from the second gas source 35b into the reaction tube 11, and the temperature of the semiconductor substrate 15 is reduced by the heater 16 for heating. The temperature is adjusted to 600 to 700 ° C., and the exhaust path heater 65 heats the pipe 63 a and the combination valve CV to about 100 to 150 ° C.
The valve 69 of c selects a flow path so that the exhaust gas is discharged from the first exhaust port. Further, the opening degree of the combination valve CV is controlled so that the pressure in the reaction tube 11 is 25 to
The evacuation is continued while controlling the pressure to about 50 Pa, and this state is maintained for a predetermined time, for example, 2 hours. During this time, the reaction tube 1
1, a reaction represented by the chemical formula 1 occurs, and the semiconductor substrate 1
5, a silicon nitride film (Si ₃ N ₄ film) is formed.

[0060]

Embedded image 10NH ₃ + 3SiH ₂ Cl ₂ → Si ₃ N ₄ +6
NH ₄ Cl + 6H ₂

During this film forming process, the heating section of the hot disk trap TRP1
1 is heated to about 100 ° C. to 150 ° C.
This prevents the exhaust gas from being cooled by these disks, and thus the by-product N in the exhaust gas
H ₄ Cl is prevented from sticking to these disks.

The by-product NH ₄ Cl in the exhaust gas is cooled and collected by the switching trap TRP2 during the film forming process. The exhaust gas flowing out of the switching trap TRP2 is sucked by the vacuum pump VP, discharged to the pipe 63c, and discharged from the first exhaust port of the pipe 63c.

After the film formation of the silicon nitride film Si ₃ N ₄ is completed, the valves VB 1 and VB 2 are closed, the supply of the reaction gas is stopped, and the opening of the combination valve CV is controlled while the vacuum pump VP is driven. Then, the pressure inside the reaction tube 11 is reduced again to about 0.1 Pa by performing slow exhaust.

When the pressure in the reaction tube 11 reaches a predetermined value,
By opening the valve VB5, alkoxysilane (preferably TEOS) is supplied into the reaction tube 11 from the third gas source 35c, and the semiconductor substrate 15 is heated by the heater 16 for temperature rise.
Is adjusted to about 700 ° C. In addition, the exhaust path heater 65 keeps the piping 63a and the combination valve CV at about 100C to 150C. Then, the evacuation is continued while controlling the opening of the combination valve CV to control the pressure in the reaction tube 11 to about 60 Pa, and this state is maintained for a predetermined time, for example, 20 minutes. Third gas source 35
When the gas supplied from c is TEOS, the reaction tube 11
The reaction shown in Chemical Formula 2 occurs in the semiconductor substrate 15
A silicon oxide film (SiO ₂ film) is formed on the surface of the substrate.

[0065]

## STR2 ## _{TEOS → SiO 2 + C x H} y + H 2 O x, y are natural numbers

The hydrocarbon C _x which is a by-product in the exhaust gas
H _y, in order to decrease the exhaust conductance in the hot disk trap TRP1, attached to each disc, is removed from the exhaust gas. On the other hand, the exhaust gas also NH 4 _Cl caused such NH 4 _Cl was relatively fixed low temperature portion of the manifold 17 and the like near the exhaust pipe 61 between the film forming process the Si ₃ N ₄ film is sublimated include. However, NH ₄
Cl means that the heating unit of the hot disk trap TRP1 heats each disk of the hot disk trap TRP1 at 100 ° C.
Since it is heated to about 150 ° C., it does not adhere to each disk and is collected by the switching trap TRP2. The exhaust gas flowing out of the switching trap TRP2 passes through the vacuum pump VP and is exhausted from the first exhaust port selected by the valve 69 of the pipe 63c.

However, during this film forming process, silicon oxide SiO ₂ adheres to the inner surface of the reaction tube 11, the lower end of the manifold 17, the bent portion of the pipe 63 a, the inside of the hot disk trap TRP 1, etc. Silicon oxide SiO ₂ , hydrocarbons C _x H _{y, and the} like adhere to some extent to a portion where the conductance of the flow channel is low.

After the film forming process is completed, the supply of the reaction gas is stopped by closing the valve VB5, and the pressure inside the reaction tube 11 is reduced again to 0.5 to 0.7 Pa by the vacuum pump VP. Subsequently, the combination valve CV is closed, and the valve VB3 is closed.
And VB4 are opened to supply nitrogen gas into the reaction tube 11 from the nitrogen gas sources 36a and 36b, thereby returning the inside of the reaction tube 11 to a normal pressure state (atmospheric pressure). Thereafter, for a predetermined time, for example, 15
Let cool for minutes.

Thereafter, the combination valve CV is opened, and while controlling the opening degree, the gas in the reaction tube 11 is sucked at a pressure difference of about -500 Pa with respect to the pressure in the reaction tube 11 (that is, the atmospheric pressure). Then, the lifting mechanism 54 is driven to move the wafer boat 14 to the reaction tube 11 as shown in FIG.
To unload and unload the semiconductor substrate 15. When the wafer boat 14 is unloaded, NH ₄ Cl adhering to a low-temperature portion or the like in the reaction tube 11 sublimes when the high-temperature semiconductor substrate 15 after the heat treatment passes in the vicinity, and the sublimation gas causes moisture in the atmosphere. May react with and generate particles. However, by employing such an unloading method, as schematically shown in FIG. 3, sublimation gas and particles are gently sucked, and the semiconductor substrate 15
Exhausted without adhering to

Next, the semiconductor substrate 1 together with the wafer boat 14 is
The semiconductor substrate 15 is unloaded and, if necessary, the semiconductor substrate 15 is transferred to a cassette or the like.

Subsequently, in order to clean the inside of the vertical heat treatment apparatus, the elevating mechanism 54 is raised, the lid 51 is moved upward, and the flange 22 of the manifold 17 and the lid 51 are moved.
Reach an airtight state via the O-ring 52.
When the wafer boat 14 is also cleaned, the wafer boat 14 after the transfer of the semiconductor substrate 15 is placed in the heat retaining cylinder 53. Further, the valve 69 of the pipe 63c selects a flow path so that exhaust gas is discharged from the second exhaust port.

While the vacuum pump VP is activated, the combination valve CV is controlled so that the piping 63a
The pressure is reduced to about Pa to 30 kPa. Further, the inside of the reaction tube 11 is heated to about 50 ° C. by the heater 16 for temperature rise,
The heating unit of the hot disk trap TRP1 is used to heat each disk of the hot disk trap TRP1 from 100 ° C. to
The heating is continued to about 0 ° C.
Also, the piping 63a and the combination valve CV
Continue heating to 00-150 ° C.

Next, the valve VB6 is opened, and hydrogen fluoride is supplied to the inlets 64a to 64c for a predetermined time, for example, about 1 hour.
Feed for 0 minutes. Hydrogen fluoride flows into the lower end of the manifold 17 from the inlet 64a, and flows into the inlet 64a.
b flows into the upstream side of the bent portion of the pipe 63a, flows from the inlet 64c into the gas inlet of the hot disk trap TRP1, and flows toward the vacuum pump VP.

The hydrogen fluoride supplied to the inlets 64 a to 64 c causes the silicon oxide SiO ₂ itself adhered to the inner surface of the reaction tube 11, the lower end of the manifold 17,
The bent portion of the pipe 63a or the hot disk trap TRP
And internal one, hydrocarbons C _x H _y such that the conductance of the channel is attached to the lower part is separated from these parts (i.e. washed), via a vacuum pump VP, are selected by the valve 69 of the pipe 63c Is discharged from the second exhaust port.

After the cleaning is completed, the supply of hydrogen fluoride is stopped by closing the valve VB6, and the reaction tube 1 is turned on by the vacuum pump VP.
The pressure in 1 is reduced to 0.5 to 0.7 Pa. Subsequently, the valves VB3 and VB4 are opened, and the nitrogen gas sources 36a and 36b are opened.
Then, nitrogen gas is supplied into the reaction tube 11 to perform purging.
This is repeated several times, and then the inside of the reaction tube 11 is returned to the normal pressure state (atmospheric pressure).

As described above, according to the vertical heat treatment apparatus according to the first embodiment, in the heat treatment apparatus for forming a plurality of types of films, the reaction by-products contained in the exhaust gas during the film formation are reduced. , And the attached products (main products and reaction by-products) can be easily washed without decomposing and desorbing the apparatus. Therefore,
It is possible to improve the utilization efficiency of the device and reduce the maintenance cost.

At the time of cleaning, a mixed gas of hydrogen fluoride and another gas may be supplied to the reaction pipe 11 and the exhaust pipe 63. For example, during cleaning, valves VB6 and VB3 (or
B4) may be opened to introduce hydrogen fluoride and nitrogen into the reaction tube 11 and the exhaust pipe 63. The temperature of the reaction tube 50 at the time of washing is not limited to 50 ° C.
It can be set appropriately between about 0 and 200 ° C.

(Second Embodiment) In the first embodiment, when cleaning is performed by supplying hydrogen fluoride to the inlets 64a to 64c after the film forming process is completed, the inside of the pipe 63a is set to 10 kP.
a is maintained at about 30 kPa.

In general, when cleaning by supplying hydrogen fluoride as described above, the cleaning effect appears at 10 kPa or more.
At a pressure of about 20 kPa, the adhered matter is most easily separated. However, if the pressure is maintained at a constant value of about 10 kPa to 30 kPa, hydrogen fluoride hardly reaches a part where the conductance is low or a part where the gas flow is stagnant, and the attached matter may remain without being separated. . For example, the manifold 17 at the lower end of the reaction tube 11 is
Since 1a to 31c are inserted and the like, there are many irregularities, and hydrogen fluoride gas does not easily permeate. Similarly, it is difficult for hydrogen fluoride to reach the vicinity of the bent portion in the exhaust pipe 63 and the connecting portion of the pipe. For this reason, the products (main products and reaction by-products) attached to the inner surfaces of the manifold 17 and the exhaust pipe 63 may remain and may not be properly removed.

Therefore, in the vertical heat treatment apparatus according to the second embodiment of the present invention, at the time of cleaning, the pressure in the reaction tube 11 is repeatedly changed to promote the penetration of the hydrogen fluoride gas, and Can be more appropriately removed.

The vertical heat treatment apparatus according to the second embodiment of the present invention has the same configuration as the vertical heat treatment apparatus according to the first embodiment.

At the time of cleaning, as in the case of the first embodiment, the lifting mechanism 54 is raised, the lid 51 is moved upward, and the flange 22 of the manifold 17 and the lid 51 are connected by an O-ring. An airtight state is reached via 52. When the wafer boat 14 is also cleaned, the wafer boat 14 after the transfer of the semiconductor substrate 15 is placed in the heat retaining cylinder 53. Also, the valve 69 of the pipe 63c
Selects a flow path such that exhaust gas is discharged from the second exhaust port.

Next, with the vacuum pump VP activated, the combination valve CV is controlled to reduce the pressure in the pipe 63a to about 10 kPa. Further, the heater 16 for raising the temperature
As a result, the inside of the reaction tube 11 is heated to about 50 ° C., and the heating unit of the hot disk trap TRP1 continues to heat each disk of the hot disk trap TRP1 to about 100 ° C. to 150 ° C. Also, the piping 63a and the combination valve CV are kept at about 100 ° C.
Continue heating to 150 ° C.

Next, the valve VB6 is opened, and hydrogen fluoride is supplied to the inlets 64a to 64c for a predetermined time, for example, about 1 hour.
Feed for 0 minutes. Hydrogen fluoride flows into the lower end of the manifold 17 from the inlet 64a, and flows into the inlet 64a.
b flows into the upstream side of the bent portion of the pipe 63a, flows from the inlet 64c into the gas inlet of the hot disk trap TRP1, and flows toward the vacuum pump VP.

The hydrogen oxide supplied to the inlets 64 a to 64 c causes the silicon oxide SiO ₂ itself adhered to the inner surface of the reaction tube 11, the lower end of the manifold 17,
The bent portion of the pipe 63a or the hot disk trap TRP
And internal one, hydrocarbons C _x H _y such that the conductance of the channel is attached to the lower part is separated from these parts (i.e. washed), via a vacuum pump VP, are selected by the valve 69 of the pipe 63c Is discharged from the second exhaust port.

At this time, by controlling the combination valve CV, the pressure in the pipe 63a is set to, for example, 0.1 kPa
It fluctuates between about 30 kPa. That is, the opening of the combination valve CV is increased, the pressure in the pipe 63a is reduced by the vacuum pump VP, and the pressure is reduced to about 0.1 kPa. Then, the opening of the combination valve CV is reduced to reduce the pressure in the pipe 63a. The pressure is increased to about 20 to 30 kPa.

The range in which the pressure in the pipe 63a fluctuates is
It depends on the evacuation capacity of the vacuum pump VP, etc.
It suffices if hydrogen fluoride gas can penetrate into the portion 1 and the low conductance in the exhaust pipe 63. In particular, the lower limit of the range of the pressure fluctuation is not limited to 0.1 kPa, but may be any pressure at which the permeation of hydrogen fluoride can be promoted to perform appropriate cleaning, for example, 2 kPa (1 to 3 kPa). I just need.

FIG. 4 is a diagram showing an example of the pressure fluctuation of the pipe 63a when the washing is performed by repeatedly changing the pressure in the reaction tube 11. As shown in FIG. In the illustrated example, the pipe 63
The pressure in a is varied between about 2 kPa and 30 kPa. Further, the pressure in the pipe 63a is changed so that a period in which the pressure in the pipe 63a is 10 kPa or more and a period in which the pressure is less than 10 kPa are periodically repeated.

At this time, as described above, the effect of the cleaning by supplying the hydrogen fluoride gas appears at 10 kPa or more. Therefore, while the hydrogen fluoride gas is convected, the piping 6
It is preferable to control the combination valve CV and the vacuum pump VP so that the period during which the pressure in 3a is 10 kPa or more is as long as possible.

As described above, by varying the pressure in the reaction tube 11, hydrogen fluoride gas penetrates into the reaction tube 11 and the low-conductance portion in the exhaust pipe 63, and the adhered products are effectively removed. Can be removed.

(Third Embodiment) As a method for removing the hydrogen fluoride gas used for cleaning in the first and second embodiments, the supply of nitrogen gas (purge gas) and the evacuation are alternately performed. There is a method that can be repeated.

For example, as shown in the sequence diagram of FIG. 5, after cleaning with hydrogen fluoride gas and subsequent evacuation, supply of nitrogen gas and evacuation are performed 11 times (1.
1 cycle) to repeat the reaction pipe 11 and the exhaust pipe 63
It is conceivable to remove hydrogen fluoride gas remaining in the gas. However, hydrogen fluoride stays in a portion with low conductance or is adsorbed in the reaction tube 11 or the exhaust pipe 63, and is efficiently removed only by alternately repeating the supply of the nitrogen gas and the evacuation. Can not do. For example, in the process shown in the sequence diagram of FIG. 5, 10 ppm or more of hydrogen fluoride remains in the reaction tube 11 and the exhaust pipe 63 despite about 5 hours.

Therefore, the vertical heat treatment apparatus according to the third embodiment of the present invention is provided with an alkoxysilane (preferably T
Using EOS, hydrogen fluoride remaining in the reaction tube 11 or the like after cleaning can be removed in a short time.

The vertical heat treatment apparatus according to the third embodiment of the present invention has the same configuration as the vertical heat treatment apparatuses according to the first and second embodiments.

FIG. 6 is a sequence diagram showing the operation of the vertical heat treatment apparatus for removing the hydrogen fluoride gas used for cleaning. Hereinafter, the operation of the vertical heat treatment apparatus shown in the sequence diagram of FIG. 6 will be described.

In this vertical heat treatment apparatus, after cleaning the inside of the reaction tube 11 and the exhaust pipe 63 with hydrogen fluoride, the valve VB6 is closed to stop the supply of hydrogen fluoride, and the vacuum pump VP is started. The pressure inside the reaction tube 11 is reduced.

Next, while the vacuum pump VP is running, the valves VB3 and VB4 are opened, and the nitrogen gas sources 36a and 36B are opened.
b, a nitrogen gas is supplied into the reaction tube 11 to control the opening degree of the combination valve CV so that the inside of the reaction tube 11
Return to about kPa. Further, the inside of the reaction tube 11 is heated to about 650 ° C. by the heater 16 for temperature rise. Thereafter, the valves VB3 and VB4 are closed, the supply of nitrogen gas into the reaction tube 11 is stopped, and the reaction tube 1 is again turned on by the vacuum pump VP.
Reduce the pressure inside 1. As described above, the pressure reduction in the reaction tube 11 and the supply of the nitrogen gas are repeated a predetermined number of times, for example, three times (three cycles).

After the pressure in the reaction tube 11 and the supply of nitrogen gas are repeated in this manner, the valve VB5 is opened while the pressure in the reaction tube 11 is reduced, and the alkoxysilane, preferably, is supplied from the third gas source 35c. TEOS is supplied into the reaction tube 11. Then, the evacuation is continued while controlling the opening of the combination valve CV to control the pressure in the reaction tube 11 to about 133 Pa, and this state is maintained for a predetermined time, for example, 2 minutes.

Next, the supply of the reaction gas is stopped by closing the valve VB5, the valves VB3 and VB4 are opened, nitrogen gas is supplied from the nitrogen gas sources 36a and 36b into the reaction tube 11, and the opening of the combination valve CV is reduced. By controlling, the inside of the reaction tube 11 is returned to about 30 kPa. After that, it is left to cool for a predetermined time, for example, 15 minutes.

Then, the vacuum pump VP and the valve VB3
By controlling VB4 and the combination valve CV, the pressure reduction in the reaction tube 11 and the supply of the nitrogen gas are repeated a predetermined number of times, for example, three times (three cycles). Thereby, the hydrogen fluoride remaining in the reaction tube 11 can be completely removed in about 4 hours. That is, the time required to remove the reaction product adhered inside can be reduced.

The number and duration of nitrogen gas supply and evacuation cycles before and after TEOS supply are not limited to 72 minutes each in three cycles, but may be any number of cycles and duration if hydrogen fluoride can be removed. Can be set to time. Further, the gas supplied for removing hydrogen fluoride is not limited to alkoxysilane for forming a silicon oxide film, but may be NH ₃ and SiH ₂ Cl ₂ for forming a silicon nitride film. That is, a film forming gas to be formed in the reaction tube 11 can be supplied.

The present invention is not limited to the first to third embodiments, and various modifications and applications are possible. For example, in the above embodiment, the combination valve CV was used to open and close the flow path from the reaction tube 11 to the vacuum pump VP. However, instead of the combination valve CV, the main valve and its own flow path were opened and closed. And a bypass pipe that is provided across the main valve. In such a configuration, when slow exhaust is performed in the above-described film forming process, or when exhaust is performed when the semiconductor substrate 15 is unloaded, by adjusting the opening of the sub-valve while the main valve is closed, Slow exhaust and exhaust at the time of unloading may be performed.

Further, the injection position of hydrogen fluoride for cleaning is arbitrary, and the products generated during the film forming process for lowering the temperature of the exhaust gas and the conductance of the exhaust gas are reduced. An inlet is provided at any place where there is a danger of sticking, and through these inlets, the fourth
May be injected into the flow path of the exhaust gas.

For example, as shown in FIG.
Instead of 4a, an inlet 64d may be provided at a position adjacent to the joint 62 to clean only the inside of the exhaust pipe 63. Alternatively, only the inlet 64a may be arranged, hydrogen fluoride may be injected into the reaction tube 11, and the exhaust pipe 63 may be washed with hydrogen fluoride flowing out of the reaction tube 11. Further, the deposition gas at the time of discharging the hydrogen fluoride may be supplied to the reaction tube 11 and / or the exhaust piping 63 from a pipe separate from the original deposition gas.

Further, in place of the switching trap TRP2, for example, one water-cooled trap substantially the same as that provided in the switching trap TRP2 may be provided. Also,
A pipe that connects the hot disk trap TRP1 and the combination valve CV to each other,
Combination valve CV and switching trap TRP2
Are connected to each other during the same period as when the exhaust path heater 65 is heating, for example, 10
You may make it heat at 0 degreeC-150 degreeC. Accordingly, hydrocarbons _C x _{H y} or the like and _NH 4 Cl may decrease to adhere to these pipes.

In the above embodiment, the semiconductor substrate 15 is loaded or unloaded into the reaction tube 11 while evacuating with the vacuum pump VP. However, the method of evacuating the reaction tube 11 is arbitrary. For example, when loading / unloading the wafer boat 14, the combination valve CV is closed and the factory exhaust valve EV is opened so that the gas in the reaction tube 11 has a pressure difference of about -50 to -700 Pa with respect to the atmospheric pressure. Alternatively, the exhaust may be controlled by a damper.

In the above embodiment, the present invention has been described by taking as an example the case of forming a silicon nitride film and a silicon oxide film. However, the present invention is not limited to the above embodiment, and various film forming processes can be performed. Applicable to For example, TiCl
₄ gas and NH ₃ gas are reacted to form TiN on the substrate to be processed.
It can also be used when a film is formed (NH ₄ Cl is produced as a reaction by-product). Further, the present invention can be applied to a case where an organic silicon compound other than alkoxysilane is used as a source gas. Further, it can also be used for forming a thin film other than the multilayer insulating film. Further, in the above-described embodiment, the present invention has been described with an example of a heat treatment apparatus for forming a film on a semiconductor substrate (semiconductor wafer). However, the present invention is applicable to an apparatus for forming a film on an arbitrary object such as a glass substrate. Applicable.

In the above embodiment, the nitrogen gas source 3
Although it has been described that nitrogen gas is supplied by 6a and 36b, the present invention is not limited to this. For example, as shown in FIG. 8, a nitrogen gas source 36 is connected to a pipe 33d via a valve VB7.
c, the opening degree of the valve VB7 may be controlled by a controller to supply nitrogen gas.

[0109]

As described above, according to the present invention,
A heat treatment apparatus capable of easily removing reaction products adhered to the inside in a short time and preventing the reaction products from adhering in a flow path of exhaust gas, and a cleaning method thereof are realized.

[Brief description of the drawings]

FIG. 1 is a diagram showing a structure of a vertical heat treatment apparatus according to an embodiment of the present invention.

FIG. 2 is a view showing a state where a wafer boat for heat treatment is taken out of the vertical heat treatment apparatus of FIG. 1;

FIG. 3 is a view schematically showing a state in which particles in a reaction tube are exhausted.

FIG. 4 is a diagram showing pressure fluctuations when cleaning the inside of a reaction tube of a vertical heat treatment apparatus according to a second embodiment of the present invention.

FIG. 5 is a sequence diagram for explaining an operation of the vertical heat treatment apparatus according to the third embodiment of the present invention.

FIG. 6 is a sequence diagram for explaining an operation of the vertical heat treatment apparatus according to the third embodiment of the present invention.

FIG. 7 is a view showing a modification of the vertical heat treatment apparatus according to the embodiment of the present invention.

FIG. 8 is a view showing a modification of the vertical heat treatment apparatus according to the embodiment of the present invention.

DESCRIPTION OF SYMBOLS 11 Reaction tube 12 Outer tube 13 Inner tube 14 Wafer boat 15 Semiconductor substrate 16 Heating heater 17 Manifold 31a to 31c Gas supply tube 32a to 32c Joint 33a to 33f Gas piping 34a to 34c MFC 35a to 35d Gas Sources 36a to 36c Nitrogen Gas Source 51 Lid 53 Heat Insulation Cylinder 54 Elevating Mechanism 61 Exhaust Pipe 63 Exhaust Pipe 63a to 63c Pipe 64a to 64d Inlet 65 Exhaust Path Heater 69 Valve TRP1 Hot Disk Trap TRP2 Switching Trap VB1 to VB7 Valve VP Vacuum pump

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/28 301 H01L 21/28 301R (72) Inventor Hiroyuki Yamamoto 1-2-2 Machiya, Shiroyama, Tsukui-gun, Kanagawa Prefecture No. 41 Tokyo Electron Tohoku Co., Ltd. Sagami Office

Claims (24)

[Claims] 1. A reaction chamber capable of accommodating an object to be processed, an exhaust pipe connected to the reaction chamber, exhaust means for exhausting gas in the reaction chamber, and a gas source of hydrogen fluoride HF piping, and the H
An HF valve installed in the F pipe for controlling the supply of hydrogen fluoride gas from the gas source, and supplying the hydrogen fluoride supplied from the gas source through the HF pipe to the inside of the exhaust pipe and / or the reaction. A heat treatment apparatus comprising: an HF gas supply unit having an inlet leading to a room; a heating unit for heating the exhaust pipe; and a pressure control unit for controlling a pressure in the exhaust pipe. 2. The exhaust pipe has a bent portion, and the inlet is disposed near the bent portion of the exhaust pipe and upstream of the flow path as viewed from a reaction chamber. 2. The heat treatment apparatus according to 1. 3. The heat treatment apparatus according to claim 1, further comprising a trap disposed in the exhaust pipe to remove a reaction product in the exhaust pipe. 4. The apparatus according to claim 3, wherein said trap means includes a plurality of traps disposed in said exhaust pipe, and said pressure control means is disposed between said plurality of traps. 3. The heat treatment apparatus according to item 1. 5. The heat treatment apparatus according to claim 3, wherein the inlet is disposed near a trap of the exhaust pipe and upstream of a flow path viewed from a reaction chamber. 6. An apparatus for forming a silicon oxide film on an object to be processed by decomposing alkoxysilane and / or forming a silicon nitride film on an object to be processed by a reaction between ammonia and dichlorosilane. The heat treatment apparatus according to any one of claims 1 to 5, further comprising: 7. The apparatus according to claim 1, wherein said pressure control means includes means for maintaining a constant pressure in said exhaust pipe by adjusting an opening degree of an exhaust pipe. The heat treatment apparatus according to claim 1. 8. The pressure control means comprises:
The heat treatment apparatus according to claim 7, wherein the pressure is maintained at kPa or more. 9. The heating apparatus further comprises a temperature raising means for raising the temperature of the reaction chamber, wherein the heating means heats the exhaust pipe to 100 ° C. to 200 ° C .;
The heat treatment apparatus according to any one of claims 1 to 8, wherein the pressure is maintained at kPa. 10. The heat treatment apparatus according to claim 1, wherein said pressure control means includes means for changing a pressure of a hydrogen fluoride atmosphere in said exhaust pipe. 11. The heat treatment apparatus according to claim 10, wherein the pressure control means changes the pressure in the exhaust pipe between 0.1 kPa and 30 kPa. 12. The pressure control means repeats a period in which the pressure in the exhaust pipe is equal to or higher than 10 kPa and a period in which the pressure in the exhaust pipe is lower than 10 kPa.
The heat treatment apparatus according to claim 10, wherein the pressure in the exhaust pipe is changed so that a period in which the pressure is equal to or higher than Pa is longer than a period in which the pressure is lower than 10 kPa. 13. A film forming gas supply means for supplying a film forming gas into the exhaust pipe and / or into the reaction chamber, and a purging gas supplying a purge gas into the exhaust pipe and / or into the reaction chamber. After the gas supply unit and the HF gas supply unit stop supplying hydrogen fluoride, the supply of the purge gas into the exhaust pipe and / or the reaction chamber is performed by the purge gas supply unit and the exhaust unit. 13. A control unit, comprising: repeating a plurality of cycles of exhausting, and supplying a film forming gas by the film forming gas supply unit during the plurality of cycles. The heat treatment apparatus according to claim 1. 14. The film forming gas supply means supplies alkoxysilane as the film forming gas, and the purge gas supply means supplies nitrogen gas as a purging gas. 3. The heat treatment apparatus according to item 1. 15. A cleaning method for cleaning at least one of a reaction chamber of a heat treatment apparatus and an exhaust pipe connected to the reaction chamber, wherein at least one of the reaction chamber and the exhaust pipe is heated, and a pressure of the exhaust pipe is increased. Cleaning by supplying hydrogen fluoride gas to at least one of the reaction chamber and the exhaust pipe while evacuating while maintaining the pressure constant. 16. The cleaning method according to claim 16, wherein hydrogen fluoride gas is supplied to at least one of the reaction chamber and the exhaust pipe while maintaining the pressure in the exhaust pipe at 10 kPa or more. Cleaning method. 17. The temperature of the reaction chamber is raised, and the exhaust pipe is
The cleaning method according to claim 15, wherein the cleaning method is performed by heating to 00 ° C. and maintaining a pressure in the exhaust pipe at 10 kPa to 30 kPa. 18. A cleaning method for cleaning at least one of a reaction chamber of a heat treatment apparatus and an exhaust pipe connected to the reaction chamber, wherein at least one of the reaction chamber and the exhaust pipe is heated, and a pressure in the exhaust pipe is increased. Cleaning by supplying hydrogen fluoride gas to at least one of the reaction chamber and the exhaust pipe while changing the pressure. 19. The pressure in the exhaust pipe is 0.1 kPa to 30 k
19. The cleaning method according to claim 18, wherein the cleaning is performed by supplying hydrogen fluoride gas to at least one of the reaction chamber and the exhaust pipe while changing the pressure between Pa and Pa. 20. A period in which the pressure in the exhaust pipe is 10 kPa or more and a period in which the pressure in the exhaust pipe is less than 10 kPa are repeated, and a period in which the pressure in the exhaust pipe is 10 kPa or more is longer than a period in which the pressure in the exhaust pipe is less than 10 kPa. The cleaning method according to claim 18, wherein the pressure is changed. 21. An object to be processed is accommodated in a reaction chamber, a silicon oxide film is formed on the object to be processed by decomposition of alkoxysilane, and / or silicon is formed on the object to be processed by a reaction between ammonia and dichlorosilane. Forming a nitride film, taking out the object to be processed from the reaction chamber after the formation, taking out the object to be processed, supplying hydrogen fluoride gas, and cleaning at least one of the reaction chamber and the exhaust pipe. The cleaning method according to any one of claims 15 to 20, wherein 22. The pressure of the hydrogen fluoride gas is reduced by removing impurities in the exhaust gas by traps at a plurality of locations in the exhaust pipe and controlling the degree of opening of the exhaust pipe between the plurality of traps. The cleaning method according to any one of claims 15 to 21, wherein the cleaning method is controlled. 23. After the supply of hydrogen fluoride gas is stopped, the pressure inside the exhaust pipe is reduced, and the supply of the purge gas and the pressure inside the exhaust pipe are performed a predetermined number of times, and then a film is formed in at least one of the reaction chamber and the exhaust pipe. The cleaning according to any one of claims 15 to 22, wherein a gas is supplied, and the supply of the purge gas and the pressure reduction in the exhaust pipe are repeated a predetermined number of times to remove the hydrogen fluoride gas. Method. 24. The cleaning method according to claim 23, wherein said purge gas is composed of nitrogen gas, and said film forming gas contains alkoxysilane.