JP3936067B2 - Combustion equipment for semiconductor manufacturing - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor manufacturing combustion apparatus for generating water vapor by introducing hydrogen and oxygen into a combustion pipe by a double pipe having an inner pipe for introducing hydrogen and an outer pipe for introducing oxygen, and burning the hydrogen. In particular, the present invention relates to a semiconductor manufacturing combustion apparatus suitably used for forming an oxide film or diffusing impurities.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a technique for performing oxidation and heat treatment of a semiconductor wafer surface using water vapor generated by reacting (combusting) hydrogen and oxygen is widely known. In this technique, a combustion apparatus as shown in FIG. 10 is frequently used.
[0003]
In the figure, 1 is a combustion tube, and 2 is a double tube for introducing hydrogen and oxygen into the combustion tube 1. In this case, the inner tube 3 is for introducing hydrogen and the outer tube 4 is for introducing oxygen. Around the double pipe 2, a heater 5 for heating hydrogen and oxygen released into the combustion pipe 1 is arranged. Therefore, the hydrogen flame 6 combusted by reaction with oxygen in the combustion pipe 1 is usually formed at the tip of the inner pipe 3. The generated water vapor is sent through a supply pipe 7 into a semiconductor processing furnace (not shown).
[0004]
Incidentally, the combustion tube 1 and the double tube 2 are generally made of quartz. The reason for this is that it has heat resistance and that impurities that are inconvenient for wafer processing are not easily mixed in the water vapor generated by the hydrogen flame 6.
[0005]
However, in the combustion apparatus having such a configuration, the heat of the hydrogen flame 6 causes a problem that the tip portion of the inner tube 3 becomes particularly hot and melts, and sends particles and quartz contamination into the furnace. There was a problem of deteriorating the characteristics of the semiconductor.
[0006]
As a means for solving this problem, for example, there is a technique described in JP-A-8-008241. In this technology, a cylindrical cover is attached to the tip of the nozzle for introducing hydrogen so that the high temperature part of the hydrogen flame is separated from the tip of the nozzle. Further, the nozzle tip is changed to a heat-resistant material such as SiC so that the deterioration of the nozzle tip is reduced.
[0007]
[Problems to be solved by the invention]
However, the technique described in Japanese Patent Laid-Open No. 8-008241 has a problem that it is necessary to provide an extra member for attaching a cylindrical cover to the tip of the nozzle. In addition, the method of attaching the cylindrical cover in this way can be easily attached to a single tube nozzle, but is not suitable for a double tube structure. This is because the cylindrical cover must be attached to the inner tube, in which case it must not adversely affect the presence and function of the outer tube.
[0008]
Also, by attaching this cylindrical cover, when the high temperature portion of the hydrogen flame is separated from the tip of the nozzle, the temperature of the nozzle tip will slightly decrease, but the hydrogen flame itself is in contact with the nozzle tip. Therefore, the temperature is still high, and it is not effective to the extent that it is possible to effectively prevent the tip and the deterioration of the nozzle tip.
[0009]
The present invention has been made in consideration of the above points, and is a technique capable of effectively preventing the firmness and deterioration of the inner pipe tip of the double pipe for introducing hydrogen and oxygen by a simple method. The issue is to provide.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention makes it desirable for the combustion tube to have a double-ended pipe opening having an inner pipe for introducing hydrogen and an outer pipe for introducing oxygen, and discharges hydrogen from the tip of the inner pipe. In the semiconductor manufacturing combustion apparatus that generates water vapor by burning, a cooling means for cooling the vicinity of the tip of the inner tube is provided on the outer peripheral portion of the inner tube.
[0011]
As the cooling means, it is very preferable to have a configuration including an uneven surface formed on the outer peripheral portion of the inner tube and oxygen flowing in the outer tube. In that case, the cooling means may be configured to include a plurality of annular cooling fins that make a round along the circumferential direction of the inner tube and that are formed at intervals in the axial direction of the inner tube. The cooling means may include a plurality of rib-shaped cooling fins extending in the axial direction of the inner tube and formed at intervals in the circumferential direction of the inner tube.
[0012]
Further, in the present invention, the tip opening of the double pipe having the inner pipe for introducing hydrogen and the outer pipe for introducing oxygen is desired in the combustion pipe, and the hydrogen released from the tip of the inner pipe is burned to produce water vapor. In the combustion apparatus for manufacturing a semiconductor that generates the tip, the tips of the inner tube and the outer tube are tapered. Here, the diameter of the tip of the inner tube that is tapered is set so that the hydrogen flame burns at a position away from the tip of the inner tube in relation to the flow rate of hydrogen released from the tip. Is preferred.
[0013]
Further, in the present invention, a semiconductor manufacturing combustion apparatus that generates water vapor by introducing and burning hydrogen and oxygen into a combustion pipe by a double pipe having an inner pipe for introducing hydrogen and an outer pipe for introducing oxygen. Then, a heating element arranged in the combustion tube and a laser for irradiating this heating element with a laser beam to generate heat above the ignition point temperature of hydrogen in the combustion tube are provided. In that case, the combustion tube may be formed of a transparent heat-resistant material, and the heating element may be irradiated with laser light from the outside of the combustion tube. Also, SiC can be used as the material of the heating element.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
1 is an overall configuration diagram of a semiconductor manufacturing combustion apparatus according to a first embodiment of the present invention, FIG. 2 is an enlarged plan view of a tip opening of a double tube, and FIG. 3 is surrounded by A in FIG. It is an expanded sectional view of the tip opening part of a double tube.
[0016]
In these figures, reference numeral 1 denotes a combustion tube, which is made of heat-resistant quartz or the like. A double pipe 2 is connected to one end side 11 of the combustion pipe 1, and a distal end opening 21 of the double pipe 2 is desired in the combustion pipe 1. A supply pipe 13 for introducing water vapor to a semiconductor processing furnace (not shown) is provided on the other end side 12 of the combustion pipe 1.
[0017]
The double pipe 2 has an inner pipe 3 for introducing hydrogen and an outer pipe 4 for introducing oxygen. Hydrogen (H ₂ ) and oxygen (O ₂ ) are respectively supplied to the inner pipe 3 and the outer pipe 4 from a supply facility (not shown).
[0018]
A heater 5 for heating hydrogen and oxygen released into the combustion tube 1 is disposed around the double tube 2. The temperature of the heater 5 is around 800 ° C. Therefore, the hydrogen flame 6 combusted by the reaction with oxygen in the combustion pipe 1 is formed at the tip (opening 3a portion) of the inner pipe 3.
[0019]
The first embodiment is greatly characterized in that a cooling means for cooling the vicinity of the tip of the inner tube 3 is provided on the outer peripheral portion of the inner tube 3. As for the cooling means, a concept of using a combination of the uneven surface formed on the outer peripheral portion of the inner tube 3 and oxygen flowing in the outer tube 4 is adopted.
[0020]
That is, as shown in FIG. 2 and FIG. 3, the uneven surface as the main body of the cooling means makes a round along the circumferential direction of the inner tube 3, and a plurality of annular surfaces arranged at intervals in the axial direction of the inner tube 3. It is formed by cooling fins 31. In the illustrated example, these annular cooling fins 31 are formed by increasing the thickness near the tip of the inner tube 3 or the entire thickness and providing an annular groove in the outer peripheral portion. Needless to say, the annular cooling fin 31 may have a configuration in which the thickness of the inner tube 3 is normal and protrudes from the outer peripheral surface of the inner tube 3. In any case, it is preferable to form it integrally with the inner tube 3 from the viewpoints of heat conduction and heat dissipation.
[0021]
Although both the inner tube 3 and the outer tube 4 can be made of quartz, it is preferable that at least the inner tube 3 is made of silicon carbide (SiC) having higher heat resistance than quartz.
[0022]
According to the first embodiment, since the plurality of annular cooling fins 31 are formed in the outer peripheral portion near the distal end portion of the inner tube 3, the heat dissipation effect is increased, and the distal end portion of the inner tube 3 is accordingly increased. To be cooled. At this time, the oxygen flowing in the outer tube 4 acts as a refrigerant, and a so-called heat exchange action that continuously takes away the heat of the cooling fins 31 is actively performed. Therefore, the tip of the inner tube 3 is effectively cooled.
[0023]
As a result, it is possible to efficiently prevent the distal end portion of the inner tube 3 from being melted and being deteriorated as in the prior art. In addition, since the oxygen flowing in the outer tube 4 is used as a refrigerant, the inner tube 3 can be simply configured by simply providing the cooling fins 31 in this way.
[0024]
4 and 5 are a plan view and a cross-sectional view, respectively, showing a second embodiment of the present invention. In this embodiment, the uneven surface as the main body of the cooling means is constituted by a plurality of vertical rib-shaped cooling fins 32 extending in the axial direction of the inner tube 3 and arranged at intervals in the circumferential direction of the inner tube 3. is there.
[0025]
Since the cooling fin 32 extends in the axial direction of the double pipe 2, the oxygen flowing through the outer pipe 4 can be increased even if the length of the cooling fin 32 protruding outward in the radial direction of the inner pipe 3 is increased. The problem of blocking the flow path does not occur. Accordingly, there is an advantage that the length of the cooling fin 32 protruding outward in the radial direction of the inner tube 3 can be increased to further enhance the heat dissipation effect.
[0026]
When paying attention to this point, for example, as shown in FIG. 6 as the third embodiment, a part or all of each cooling fin 33 may be abutted against the inner surface of the outer tube 4. In this way, the heat dissipation effect can be further enhanced, and the cooling fin 33 can also have a function as a spacer for positioning the inner tube 3 and the outer tube 4.
[0027]
6 shows an example in which the inner tube 3 and the outer tube 4 are configured as separate members, they may be integrally formed as one member. If it does so, it will become a very preferable structure also in terms of manufacturability.
[0028]
7 and 8 are an overall configuration diagram and an enlarged cross-sectional view of the main part showing a fourth embodiment of the present invention, respectively. This embodiment is characterized in that the tip opening of the double pipe 2 having the inner pipe 3 for introducing hydrogen and the outer pipe 4 for introducing oxygen is tapered. That is, the tip portions of both the inner tube 3 and the outer tube 4 are actively tapered.
[0029]
The diameter of the tip of the inner tube 3 to be tapered (the diameter of the opening 3a) is related to the flow rate of hydrogen released from the opening 3a at a position where the hydrogen flame 6 is away from the tip of the inner tube 3. It is set to burn. Since other configurations are the same as those of the previous embodiment, the same reference numerals are given and description thereof is omitted.
[0030]
When the front end opening 21 of the double pipe 2 is configured in this way, the flow velocity at which hydrogen and oxygen are released becomes faster, and therefore, the fire is ignited away from the front end of the inner pipe 3 and the hydrogen flame 6 is generated there. It is formed. Therefore, since the temperature of the tip of the inner tube 3 does not rise abnormally, the tip of the inner tube 3 does not become stiff, thereby preventing particles and contamination from being fed into the furnace. Moreover, since the flow rates of hydrogen and oxygen are fast, the danger of hydrogen flowing back and exploding can be fundamentally eliminated.
[0031]
FIG. 9 is an overall configuration diagram showing a fifth embodiment of the present invention. In this embodiment, the ignition method for introducing and burning hydrogen and oxygen into the combustion pipe 1 by the double pipe 2 having the inner pipe 3 for introducing hydrogen and the outer pipe 4 for introducing oxygen is devised. There is a feature in the point.
[0032]
That is, as shown in the previous embodiment, instead of arranging the heater 5 which is a heating means for hydrogen and oxygen, the heating element 7 disposed in the combustion tube 1 and the heating element 7 are irradiated with the laser beam 8a. And a laser 8 for generating heat above the ignition point temperature of hydrogen in the combustion tube 1.
[0033]
In that case, the combustion tube 1 is formed of a transparent heat-resistant material (transparent quartz glass or the like), and is configured to irradiate the heating element 7 with the laser beam 8 a from the outside of the combustion tube 1. As the laser beam, an infrared laser beam having an excellent heating effect is preferably used. Reference numeral 9 denotes a heater arranged to heat the combustion tube 1 instead of the heater that heats the double tube. The temperature of the heater 9 is kept around 200 ° C.
The material of the heating element 7 is not particularly limited as long as it is a material that does not generate impurities even when heat is generated at a temperature higher than the ignition temperature of hydrogen and has a low reflectance of infrared laser light, but is not limited to SiC (silicon carbide) or colored materials. Sapphire, silicon (Si), etc. are used.
[0034]
Although the heat generating body 7 is arrange | positioned in the center part in the combustion pipe 1, this position can also be changed suitably. However, although not particularly illustrated, the member that supports the heating element 7 also needs to be disposed in the combustion tube 1. This support member is preferably configured to support the heating element 7 from below. This is because it can be considered that the thermal effect of the hydrogen flame 6 is hardly received.
[0035]
This support member is also preferably made of a material having substantially the same performance as the heating element 7. Of course, the heating element 7 and the support member can also be configured by coating the surface of a base material made of another material with the above heat-resistant material.
[0036]
According to this embodiment, the hydrogen flame 6 ignited using the heating element 7 heated by the laser beam 8 a as a heat source burns at a position away from the tip of the inner tube 3. Therefore, the temperature of the tip of the inner tube 3 does not rise abnormally, so that the tip does not stay steady. Thereby, it is possible to prevent particles and contamination from being fed into the furnace.
[0037]
Further, since the heating element 7 serving as a heat source for ignition is present in the combustion pipe 1, a heater disposed around the double pipe 2 as in the previous embodiment can be eliminated. From this point of view, the heater 9 for heating the combustion tube 1 is basically unnecessary. However, this is effective from the viewpoint of keeping the temperature of the double pipe 2 itself so as not to decrease too much. The reason for this is that hydrogen ignition, combustion, and end of combustion are usually repeated, and the temperature change at that time can be reduced.
[0038]
In the above embodiment, an example in which the present invention is applied to a combustion apparatus outside the semiconductor processing furnace has been described. However, the present invention can also be applied to an apparatus in which this combustion apparatus is provided inside the semiconductor processing furnace.
[0039]
【The invention's effect】
As described above, according to the present invention, an apparatus for generating water vapor by introducing and burning hydrogen and oxygen into a combustion pipe by a double pipe having an inner pipe for introducing hydrogen and an outer pipe for introducing oxygen. The cooling means for cooling the vicinity of the tip portion of the inner tube is provided on the outer peripheral portion of the inner tube, so that it is possible to effectively prevent the inner tube tip portion due to hydrogen flame from being worn and deteriorated by a simple method. it can.
[0040]
Also, by actively tapering the tips of the inner and outer tubes, the flow rate at which hydrogen and oxygen are released can be increased, and a hydrogen flame can be formed away from the tip of the inner tube. it can. Accordingly, since the temperature of the tip of the inner tube does not rise abnormally, the tip of the inner tube does not become persistent, thereby preventing particles and contamination from being fed into the furnace. Moreover, since the flow rates of hydrogen and oxygen are fast, the danger of hydrogen flowing back and exploding can be fundamentally eliminated.
[0041]
Further, according to the present invention, when hydrogen and oxygen are introduced into a combustion tube and burned by a double tube having an inner tube for introducing hydrogen and an outer tube for introducing oxygen, the heating element disposed in the combustion tube Since the hydrogen flame is separated from the tip portion of the inner tube by irradiating the laser beam with the laser beam, it is possible to further reliably prevent the inner tube tip portion from being moistened and deteriorated.
[Brief description of the drawings]
1 is an overall configuration diagram of a semiconductor manufacturing combustion apparatus according to a first embodiment of the present invention;
FIG. 2 is a plan view showing the tip opening of the double pipe of the semiconductor manufacturing combustion apparatus according to the first embodiment of the present invention.
FIG. 3 is a cross-sectional view showing the tip opening of the double pipe of the semiconductor manufacturing combustion apparatus according to the first embodiment of the present invention.
FIG. 4 is a plan view showing a tip opening of a double pipe of a semiconductor manufacturing combustion apparatus according to a second embodiment of the present invention.
FIG. 5 is a cross-sectional view showing a tip opening of a double pipe of a semiconductor manufacturing combustion apparatus according to a second embodiment of the present invention.
FIG. 6 is a plan view showing a tip opening of a double pipe of a semiconductor manufacturing combustion apparatus according to a third embodiment of the present invention.
FIG. 7 is an overall configuration diagram of a semiconductor manufacturing combustion apparatus according to a fourth embodiment of the present invention.
FIG. 8 is a cross-sectional view showing a tip opening of a double pipe of a semiconductor manufacturing combustion apparatus according to a fourth embodiment of the present invention.
FIG. 9 is an overall configuration diagram of a semiconductor manufacturing combustion apparatus according to a fifth embodiment of the present invention.
FIG. 10 is an overall configuration diagram of a conventional combustion apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Combustion pipe 2 Double pipe 3 Inner pipe 3a Opening 4 Outer pipe 5 Heater 6 Hydrogen flame 7 Supply pipe 8 Laser 8a Laser light 9 Heater 11 One end side 12 Other end side 13 Supply pipe 21 Tip opening 31 Annular cooling fin (cooling) means)
32, 33 Rib-shaped cooling fin (cooling means)

Claims (8)

For manufacturing semiconductors that produce a water vapor by burning the hydrogen released from the tip of the inner tube, with the tip opening of the double tube having an inner tube for introducing hydrogen and an outer tube for introducing oxygen in the combustion tube in the combustion apparatus, the outer peripheral portion of the inner tube, characterized in that a plurality of cooling fins is a cooling means for cooling the vicinity of the distal end portion of the inner tube, semiconductor manufacture combustion device.   2. The semiconductor manufacturing combustion according to claim 1, wherein the cooling means is composed of a plurality of annular cooling fins that make a round along a circumferential direction of the inner pipe and are spaced apart in an axial direction of the inner pipe. apparatus.   2. The combustion apparatus for manufacturing a semiconductor device according to claim 1, wherein the cooling means includes a plurality of vertical rib-shaped cooling fins extending in an axial direction of the inner pipe and arranged at intervals in a circumferential direction of the inner pipe. .   4. The semiconductor manufacturing combustion apparatus according to claim 3, wherein the cooling means is configured such that a part or all of the vertical rib-shaped cooling fins abut against an inner surface of the outer tube. For manufacturing semiconductors that produce a water vapor by burning the hydrogen released from the tip of the inner tube, with the tip opening of the double tube having an inner tube for introducing hydrogen and an outer tube for introducing oxygen in the combustion tube A combustion device,
A heating element disposed in the combustion tube, the heating element disposed at a position spaced from the tip of the inner tube;
A semiconductor manufacturing combustion apparatus comprising: a laser for irradiating the heating element with a laser beam to generate heat above the ignition point temperature of hydrogen in the combustion tube.   6. The semiconductor manufacturing combustion apparatus according to claim 5, wherein the heating element is arranged at a position where a hydrogen flame ignited as a heat source burns at a position away from a tip portion of the inner tube.   7. The semiconductor manufacturing combustion apparatus according to claim 5, wherein the tip opening is formed in a tapered shape.   The combustion apparatus for manufacturing a semiconductor according to any one of claims 1 to 7, wherein the inner pipe is formed of silicon carbide.

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