JP2004162124A - Substrate processing apparatus and processing method - Google Patents

Abstract

An object of the present invention is to provide a substrate processing apparatus capable of reliably and efficiently decomposing and removing organic substances attached to a substrate by using excited oxygen.
A substrate processing apparatus for decomposing and removing organic substances attached to a substrate with excited oxygen is provided.
A chamber 1 to which the substrate is supplied, a low-pressure mercury lamp 7 that excites oxygen in the chamber to generate excited oxygen, and an oxygen in the chamber by controlling the amount of an inert gas supplied to the chamber. A control device 15 for setting the concentration within a predetermined range.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a substrate processing apparatus and method for decomposing and removing organic substances attached to a substrate by excited oxygen generated by exciting oxygen.
[0002]
[Prior art]
For example, in a manufacturing process of a semiconductor device or a liquid crystal display device, there are a film forming process and a photo process for forming a circuit pattern on a substrate such as a semiconductor wafer or a rectangular glass substrate for a liquid crystal display. In these processes, a chemical treatment, a cleaning treatment with a cleaning liquid, a drying treatment, and the like of the substrate are repeatedly performed.
[0003]
In order to enhance the cleanliness of the substrate, there is a step of decomposing and removing organic substances attached to the substrate before or after the above-described various treatments. Organic substances are decomposed and removed by excited oxygen generated by exciting oxygen.
[0004]
That is, the substrate is transferred into the chamber, an ultraviolet lamp such as a low-pressure mercury lamp or an excimer lamp provided in the chamber is turned on, and the inside of the chamber is irradiated with ultraviolet light emitted from the ultraviolet lamp. A lamp used for decomposing and removing organic substances excites oxygen in a chamber to generate excited oxygen.
[0005]
Therefore, when the inside of the chamber is irradiated with the ultraviolet rays emitted from the ultraviolet lamp, excited oxygen is generated in the chamber, and the organic substances attached to the substrate can be decomposed and removed by the excited oxygen.
[0006]
[Problems to be solved by the invention]
By the way, when the inside of the chamber is irradiated with ultraviolet rays, in order to generate excited oxygen in this chamber, oxygen must be present in the chamber as described above, while ultraviolet rays are easily absorbed by oxygen. Therefore, if the oxygen concentration in the chamber is simply increased, the ultraviolet rays are absorbed by oxygen before reaching the substrate and are reduced.
[0007]
Therefore, the amount of ultraviolet light reaching the substrate is reduced, and the amount of ultraviolet light that excites oxygen on the upper surface of the substrate is reduced. Therefore, the amount of excited oxygen is also reduced, and organic substances attached to the substrate cannot be reliably decomposed and removed. There is that.
[0008]
It is an object of the present invention to provide a substrate processing apparatus and a processing method capable of reliably generating excited oxygen for decomposing and removing organic substances attached to a substrate in a chamber.
[0009]
[Means for Solving the Problems]
The invention according to claim 1 is a substrate processing apparatus for decomposing and removing organic substances attached to a substrate with excited oxygen,
A chamber in which the substrate is supplied,
An excitation unit that excites oxygen in the chamber to generate excited oxygen;
Control means for controlling the amount of inert gas supplied into the chamber to set the oxygen concentration in the chamber;
A substrate processing apparatus comprising:
[0010]
A second aspect of the present invention is the substrate processing apparatus according to the first aspect, wherein the control means sets the oxygen concentration in the chamber to a range larger than 0 and smaller than 5%.
[0011]
According to a third aspect of the present invention, the control means includes an exhaust device for exhausting the atmosphere in the chamber at a constant flow rate, a supply unit for supplying an inert gas to the chamber via a flow control valve, and A control device for controlling the opening of the flow control valve so that the supply amount of the inert gas supplied from the exhaust device is reduced by a predetermined amount from the exhaust amount of the exhaust device,
And a substrate processing apparatus.
[0012]
According to a fourth aspect of the present invention, there is provided a substrate processing method for decomposing and removing an organic substance attached to a substrate with excited oxygen.
Supplying the substrate into the chamber;
Supplying an inert gas into the chamber, and controlling the supply amount of the inert gas to set an oxygen concentration in the chamber;
Exciting the oxygen in the chamber to generate the excited oxygen,
A method for processing a substrate, comprising:
[0013]
According to a fifth aspect of the present invention, there is provided the substrate processing method according to the fourth aspect, wherein the oxygen concentration in the chamber is set to a range larger than 0 and smaller than 5%.
[0014]
According to the present invention, by controlling the supply amount of the inert gas supplied into the chamber and setting the oxygen concentration in the chamber, it is possible to prevent the ultraviolet rays from being excessively absorbed by the oxygen and to surely generate the excited oxygen. Can be done.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0016]
1 to 3 show a first embodiment of the present invention. FIG. 1 shows a substrate processing apparatus, which has a chamber 1 whose internal space is open to the atmosphere. At one end of the chamber 1, a carry-in port 2a is formed, and at the other end, a carry-out port 2b is formed at substantially the same height. The entrance 2a and the exit 2b are each opened and closed by a shutter 3.
[0017]
A plurality of transport shafts 5 having transport rollers 4 are arranged in the chamber 1 with their axes substantially parallel to each other. The transport shaft 5 is driven to rotate by a drive source (not shown). Thereby, the substrate W carried into the chamber 1 from the carry-in port 2a is carried out from the carry-out port 2b.
[0018]
In the chamber 1, a plurality of low-pressure mercury lamps 7 constituting an excitation means are arranged. The low-pressure mercury lamp 7 has a length substantially equal to the width dimension of the substrate W, and is disposed above the substrate W transported by the transport roller 4 at predetermined intervals along the transport direction of the substrate W. .
[0019]
The low-pressure mercury lamp 7 outputs ultraviolet light having two peaks, a wavelength for exciting oxygen to ozone gas and a wavelength for exciting ozone gas to generate excited oxygen. That is, the low-pressure mercury lamp 7 outputs ultraviolet light having a wavelength in the range of 158 to 300 nm, and has peaks at 184.9 nm and 253.7 nm. Ultraviolet light having a wavelength of 184.9 nm excites oxygen to generate ozone gas, and ultraviolet light having a wavelength of 253.7 nm excites ozone gas to generate excited oxygen.
[0020]
An inert gas, such as N ₂ , Ne, Ar, or H _2, which is not excited by ultraviolet rays, is supplied into the chamber 1 by the main supply pipe 11. That is, the distal end side of the main supply pipe 11 is branched into a plurality of branch pipes 11a, and each of the branch pipes 11a communicates with the inside of the chamber 1 from both side walls. The base end of the main supply pipe 11 is connected to a supply section 14A of an inert gas such as a cylinder via a flow meter 12 and a flow control valve 13.
[0021]
An exhaust device 14 is provided at the bottom of the chamber 1 so that the atmosphere in the chamber 1 can be exhausted at a constant flow rate per unit time.
[0022]
The supply amount of the inert gas supplied into the chamber 1 from the supply unit 14A is detected by the flow meter 12. The detection signal from the flow meter 12 is input to the control device 15. The control device 15 controls the opening degree of the flow control valve 13, and the amount of the inert gas supplied to the chamber 1 is slightly smaller than the exhaust amount of the atmosphere in the chamber 1 exhausted from the exhaust device 14. Set to be.
[0023]
Thereby, the difference between the supply amount of the inert gas supplied into the chamber 1 and the exhaust amount in the chamber 1 exhausted by the exhaust device 14 is set in the chamber 1 from the carry-in port 2 and the carry-out port 3. Since the outside air flows, the amount of oxygen in the chamber 1 is set according to the difference. In this embodiment, the supply amount of the inert gas is controlled such that the oxygen concentration in the chamber 1 is in a range larger than 0 and smaller than 10%, preferably in a range larger than 0 and smaller than 5%. Is done.
[0024]
Next, the operation when the organic substance on the substrate W is decomposed by the processing apparatus having the above configuration will be described.
[0025]
When the substrate W is carried into the chamber 1 from the carry-in port 2, the substrate W is transported to a position below the low-pressure mercury lamp 7 and stopped, and the low-pressure mercury lamp 7 is turned on. Thereby, ultraviolet rays are emitted from each low-pressure mercury lamp 7.
[0026]
Ultraviolet light emitted from the low-pressure mercury lamp 7 has two peaks, a wavelength at which oxygen is excited to be converted into ozone gas and a wavelength at which ozone gas is excited to generate excited oxygen. Therefore, when ultraviolet rays are radiated into the chamber 1, oxygen in the chamber 1 is excited to be converted into ozone gas, and then the ozone gas is excited to generate excited oxygen. Organic matter is decomposed and removed.
[0027]
The atmosphere in the chamber 1 is controlled by an inert gas so that the oxygen concentration is in a range of more than 0 and less than 10%, and in this embodiment, in a range of more than 0 and 5% or less. Experiments have confirmed that by setting the oxygen concentration in the chamber 1 in this manner, organic substances attached to the substrate W can be efficiently decomposed and removed.
[0028]
That is, when the oxygen concentration is 0, no ozone gas is generated, and accordingly no excited oxygen is generated. Therefore, it is impossible to decompose and remove the organic matter attached to the substrate W.
[0029]
When the oxygen concentration becomes 10% or more, the amount of generated ozone gas is sufficient, but since the amount of oxygen is too large, ultraviolet rays having a wavelength for exciting the ozone gas are absorbed by oxygen, and the ultraviolet rays having that wavelength reach the upper surface of the substrate W. It becomes difficult.
[0030]
As a result, the ultraviolet light is diluted near the upper surface of the substrate W, and the ultraviolet light hardly excites the ozone gas. As a result, excited oxygen is less likely to be efficiently generated in the vicinity of the upper surface of the substrate W, so that organic substances attached to the substrate W cannot be decomposed and removed efficiently and reliably.
[0031]
However, in the present invention, as described above, the oxygen concentration in the chamber 1 is set to a range in which excited oxygen acting on the substrate W is generated in the chamber 1 by the irradiation of the ultraviolet rays. That is, the oxygen concentration was set to a range larger than 0 and smaller than 10%, and preferably set to a range larger than 0 and smaller than 5%.
[0032]
Therefore, the atmosphere in the chamber 1 in which the oxygen concentration is set to the above-described concentration by the inert gas is excited by the ultraviolet light output from the low-pressure mercury lamp 12, so that the excited oxygen is reliably generated in the chamber 1. Therefore, organic substances attached to the plate surface of the substrate W can be decomposed and removed by the excited oxygen.
[0033]
That is, according to the processing apparatus having the above configuration, the oxygen concentration in the chamber 1 is controlled by controlling the supply amount of the inert gas to the chamber 1 in accordance with the exhaust amount from the chamber 1. The concentration is set such that excited oxygen is reliably generated.
[0034]
Therefore, the excited oxygen can reliably act on the substrate W transferred into the chamber 1, so that the organic substances attached to the substrate W can be reliably decomposed and removed.
[0035]
The graph of FIG. 3 shows the result of measuring the relationship between the oxygen concentration in the chamber 1 and the contact angle value indicating the state of removal of the organic substances attached to the substrate W. In the graph of FIG. 3, the vertical axis represents the contact angle value indicating the wettability of the substrate W after the treatment, and the smaller the value, the smaller the amount of organic substances remaining on the substrate W.
[0036]
That is, as can be seen from FIG. %, The contact angle of the substrate W was about 3 °. The contact angle value was 2 ° when the treatment was performed at an oxygen concentration of 3%, and the contact angle value was about 3 ° when the treatment was performed at an oxygen concentration of 5%. As described above, organic substances were successfully removed from the substrate W when the oxygen concentration was larger than 0 and within 5%.
[0037]
When the substrate W is processed with the oxygen concentration in the chamber 1 set to 10%, the contact angle value of the processed substrate W is about 9 °, which is smaller than the case where the oxygen concentration is smaller than 5%. Although increased, the state of removal of organic substances from the substrate W was within a range in which there was no problem in practical use.
[0038]
On the other hand, if the oxygen concentration exceeds 10%, the contact angle increases, and the amount of organic substances remaining on the substrate W increases. Therefore, it is desirable that the oxygen concentration in the chamber 1 be 10% or less. For example, it was confirmed that when the oxygen concentration was 20%, the contact angle value was about 11 °, and when the oxygen concentration was larger than 10%, the contact angle value was correspondingly increased.
[0039]
From the above experimental results, if the supply of the inert gas to the chamber 1 is controlled so that the oxygen concentration in the chamber 1 becomes smaller than 10%, the organic substances attached to the substrate W can be removed satisfactorily. Furthermore, it was confirmed that when the oxygen concentration in the chamber 1 was smaller than 5%, the removal of organic substances could be performed more reliably.
[0040]
The present invention is not limited to the above-described first embodiment, and as an excitation means for generating excited oxygen, for example, as shown in FIG. Thus, a window 21 is formed, and a lamp accommodating chamber 22 is formed above the window 21. Then, instead of the low-pressure mercury lamp as the excitation means, an excimer lamp 7A that outputs ultraviolet light having a wavelength of 172 nm may be housed in the lamp housing chamber 22.
[0041]
In the case of the excimer lamp 7A, after oxygen is ozonized by ultraviolet light having a wavelength of 172 nm, excited oxygen is generated. Therefore, even when the excimer lamp 7A is used, excited oxygen can be generated as in the first embodiment.
[0042]
In order to control the oxygen concentration in the chamber 1, the amount of exhaust gas from the chamber 1 is fixed and the supply amount of the inert gas is controlled. However, the amount of exhaust gas is controlled to supply the inert gas. The amount may be made constant, and it is essential that the oxygen concentration in the chamber 1 be controlled. Further, the lower limit of the oxygen concentration in the chamber 1 is not limited to 1%, and if it is larger than 0 and smaller than 10%, excited oxygen can be generated in the chamber 1 without fail.
[0043]
FIG. 5 shows a third embodiment of the present invention. In this embodiment, the length of the chamber 1A is set to be shorter than the length of the substrate W in the transport direction, and the upper surface of the substrate W transported by the transport rollers 4 of the chamber 1A is excited. A first electrode 31 and a second electrode 32 constituting the means are arranged to face each other at a predetermined interval. The first electrode 31 is grounded via a high frequency power supply 33, and the second electrode 32 is grounded.
[0044]
The branch pipe 11a branched from the main supply pipe 11 is connected to a portion corresponding to between the pair of electrodes 31 and 32, and an inert gas is supplied into the chamber 1A from a space between the electrodes 31 and 32, and the chamber 1A Is set to a predetermined value. As the type of the inert gas supplied to the chamber 1A, a type that is not excited by plasma generated between the pair of electrodes 31 and 32 is used.
Note that the carry-in port 2a and the carry-out port 2b of the chamber 1A are open. The oxygen concentration in the chamber 1A is set in the same manner as in the first embodiment by the supply amount of the inert gas and the exhaust amount by the exhaust device 14.
[0045]
According to such a configuration, when a high-frequency voltage is applied to the pair of electrodes 31 and 32, plasma is generated between the electrodes and the plasma excites oxygen in the chamber 1A. Excited oxygen can be generated to decompose and remove organic substances attached to the substrate W.
[0046]
Therefore, if the substrate W is passed through the chamber 1A while being transported at a predetermined speed, the organic substances attached to the substrate W can be decomposed and removed. In this case, as in the first embodiment, since the contact angle value of the processed substrate W is determined according to the oxygen concentration in the chamber 1A, the oxygen concentration is set to a value larger than 0 and smaller than 10%. By setting the value to preferably less than 5%, it is possible to reliably perform the decomposition and removal of organic substances.
[0047]
FIG. 6 shows a fourth embodiment of the present invention. This embodiment is different from the third embodiment shown in FIG. 5 in the arrangement of the first electrode 31 and the second electrode 32. That is, the first electrode 31 is provided above the substrate W to be transferred, and the second electrode 32 is provided below. The inert gas is supplied from both sides of the first electrode 31 toward the substrate W by the branch pipe 11a.
[0048]
Even in such a structure, similarly to the third embodiment shown in FIG. 5, excited oxygen for decomposing and removing organic substances attached to the substrate W is generated by plasma generated between the pair of electrodes 31 and 32. Can be.
[0049]
【The invention's effect】
As described above, according to the present invention, the oxygen concentration in the chamber is set by controlling the amount of the inert gas supplied into the chamber. Excited oxygen for removal can be reliably generated.
[Brief description of the drawings]
FIG. 1 is a side sectional view of a processing apparatus according to a first embodiment of the present invention.
FIG. 2 is a plan view of the processing apparatus of FIG. 1;
FIG. 3 is a graph showing the relationship between the oxygen concentration in a chamber and the contact angle value of a substrate after processing.
FIG. 4 is a longitudinal sectional view showing a processing apparatus according to a second embodiment of the present invention.
FIG. 5 is a side sectional view showing a processing apparatus according to a third embodiment of the present invention.
FIG. 6 is a side sectional view showing a processing apparatus according to a fourth embodiment of the present invention.
[Explanation of symbols]
1 chamber 7 low-pressure mercury lamp (excitation means)
7A: Excimer lamp (excitation means)
13. Flow control valve (control means)
14 Exhaust device (control means)
15 ... Control device (control means)
31, 32 ... electrodes (excitation means)

Claims (5)

In a substrate processing apparatus for decomposing and removing organic substances attached to a substrate with excited oxygen,
A chamber in which the substrate is supplied,
An excitation unit that excites oxygen in the chamber to generate excited oxygen;
Control means for controlling the amount of inert gas supplied into the chamber to set the oxygen concentration in the chamber;
A substrate processing apparatus, comprising: 2. The substrate processing apparatus according to claim 1, wherein the control unit sets the oxygen concentration in the chamber to a range larger than 0 and smaller than 5%. An exhaust device for exhausting the atmosphere in the chamber at a constant flow rate, a supply unit for supplying an inert gas to the chamber via a flow control valve, and an inert gas supplied from the supply unit A control device that controls the opening of the flow control valve so that the supply amount of the exhaust gas is smaller than the exhaust amount of the exhaust device by a predetermined amount,
A substrate processing apparatus characterized by comprising: In a substrate processing method of decomposing and removing organic substances attached to a substrate with excited oxygen,
Supplying the substrate into the chamber;
Supplying an inert gas into the chamber, and controlling the supply amount of the inert gas to set the oxygen concentration in the chamber;
Exciting the oxygen in the chamber to generate the excited oxygen,
A method for processing a substrate, comprising: 5. The substrate processing method according to claim 4, wherein the oxygen concentration in the chamber is set in a range larger than 0 and smaller than 5%.

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