JP2676405B2 - Quartz glass for semiconductor manufacturing equipment or jig and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention relates to a quartz glass body used for manufacturing a semiconductor manufacturing apparatus or a jig whose at least one surface side is exposed to a high temperature of approximately 1000 ° C or more, and its manufacture. More particularly, the present invention relates to a quartz glass body used as a crucible for pulling a single crystal, a port used for a high temperature reaction treatment of a wafer, a furnace core tube, a carrying jig, and a manufacturing method thereof.

“Prior Art” Conventionally, a wafer heat treatment apparatus such as oxidation, diffusion, vapor phase growth or the like for producing an oxide film, an insulating film, a single crystal film or the like on the surface of a semiconductor wafer in a high temperature atmosphere has been known, and such a heat treatment In a boat, furnace core tube, transfer jig, etc. used in the apparatus, a high-purity quartz glass material having high chemical stability is generally used in order to prevent adhesion or intrusion of impurities to the surface of the formed film.

On the other hand, although the temperature in the heat treatment furnace is increasing to about 1300 ° C. in proportion to the high integration of the chip memory, the high-purity quartz glass material such as the boat exposed to the atmosphere is It softens at temperatures around 1150 ° C and becomes extremely deformable at around 1300 ° C.

Therefore, under such a treatment step, not only the durability of various jigs such as the boat becomes extremely short and the manufacturing cost rises, but also the deformation and the like of the wafer and the like supported and mounted on the boat due to the deformation. Occurs and the product yield decreases.

Various countermeasures have been taken in the past to solve such a drawback.

For example, in Japanese Utility Model Publication No. 58-92729, a boat in which a heat-resistant SiC rod or other heat-resistant core is inserted in the quartz glass tube is disclosed, but the heat-resistant core is made of quartz glass. Since the thermal expansion is remarkably large in comparison, a gap interval must be provided between the both members, and as a result, the two members collide with each other during handling at room temperature such as washing and drying, and damage or damage occurs. Cracks are likely to occur.

In order to eliminate such drawbacks, a device in which heat-resistant powder having a cushioning effect is filled between the both members (Shokai Sho-58-
No. 166032) exists, but in such a device, when the outer quartz glass tube is cracked, the powder is scattered to the outside, and the wafer is apt to be contaminated.

For this reason, a technique of inserting a low-purity quartz glass tube or rod functioning as a reinforcing material inside high-purity synthetic quartz glass without using different materials having different coefficients of thermal expansion as described above (Actual publication) No. 60-15336) is disclosed, but even with the same kind of material, it is impossible to completely avoid the contact between the two members with the structure in which the core body is inserted.

Also, since each of the above techniques is a combination of a plurality of members formed separately, it cannot be applied to a jig having a complicated shape requiring welding or the like.

Therefore, as described above, without forming heat resistance by using a plurality of members, for example, crystalline quartz particles are filled in a cylindrical heating device and heated to form a crystalline quartz body having a transparent quartz glass layer on the surface layer portion. Proposed quartz instrument (Japanese Patent Laid-Open No. 56-
No. 145123) is a crystalline quartz body having a transparent quartz glass layer on the surface layer, but even if it is heated by complicated thermal processing or heating by welding, the crystalline quartz body part of the inner layer is made transparent quartz glass. As a result, there was a problem that the heat resistance effect of the crystalline quartz body could not be obtained in the processing and heating section.

In addition, even if it is a non-processed portion in such a conventional technique, since the transparent quartz layer formed on the surface layer is a thin layer, when a holding groove for holding a wafer is engraved on the peripheral surface like a wafer support board. Not only the sintered portion is exposed to reduce the strength, especially during cleaning, the cleaning liquid and contaminants enter from the exposed sintered portion, which makes smooth cleaning difficult, and heat treatment. Occasionally, if the residue leaks out, the resulting film on the wafer surface is adversely affected.

In view of the above-mentioned drawbacks of the prior art, the present invention provides a quartz glass body having heat resistance that does not tend to soften even in a heat treatment atmosphere by using one member made of quartz glass, and a method for producing the same. To aim.

Another object of the present invention is to ensure the smoothness of the engraved portion even if a part of it is engraved so that the heat resistance is not impaired by the heat processing and the heat processing welding is facilitated. It is an object of the present invention to provide a quartz glass body and a method for producing the same that can achieve sufficient strength and easy cleaning even when the quartz glass body functions as a wafer holding groove.

"Means for solving the problem" The present invention, as shown in the following examples, for example, the soot method and VAD method and sol-gel method, which are known synthetic quartz glass manufacturing methods, or a predetermined mixture in a high-purity quartz tube. The heat-resistant fine powder or heat-resistant fiber made of silicon, carbon, or a compound thereof is added to the entire area of the quartz glass body or the inner area or the surface area extending along a predetermined direction by heating and stretching the powder-filled state. The particles are dispersed at a predetermined ratio (hereinafter, the dispersed portion is referred to as a dispersed portion).

That is, in the quartz glass body according to claim 1, a dispersion, which is a molten powder of heat-resistant fine powder or heat-resistant fibers dispersed in quartz glass powder at a predetermined ratio, is located on the center side and has a high purity. The quartz glass is located on the surface layer side, and both are integrally fused.

In this case, the heat-resistant fine powder or heat-resistant fiber is silicon,
When carbon or these compounds are used, since it does not become a semiconductor poison, the product yield does not decrease,
preferable.

A method for producing such a quartz glass body is disclosed in the invention according to claim 2, that is, a mixture of heat-resistant fine powder or heat-resistant fibers dispersed in quartz glass powder at a predetermined ratio in a high-purity quartz tube. By heating and stretching the powder in a filled state, the high-purity quartz glass located on the surface side and the dispersion, which is a melt of the mixed powder located on the center side, are integrally fused and formed. .

Further, the invention according to claims 3 and 4, the whole area of the quartz glass body or the inner area or the surface area extending along a predetermined direction,
The present invention relates to a method for dispersing heat-resistant fine powder or heat-resistant fiber made of silicon, carbon or a compound thereof at a predetermined ratio. For example, in the invention according to claim 3, silicon, carbon, or a compound thereof and Si
A quartz glass body in which a mixed soot body made of O ₂ is formed, the mixed soot body is passed through a heating source, and the heat-resistant fine powder or heat-resistant fiber made of the silicone, carbon, or a compound thereof is dispersed in the entire area. According to such a manufacturing method, the manufacturing method of the solid quartz glass body is easy.

The invention according to claim 4 is suitable for manufacturing a hollow quartz glass body, and for example, heat-resistant fine powder or heat-resistant fiber is added to quartz glass powder on the inner surface of a heat-resistant mold body rotated by a drive system. After uniformly mixing the mixed powder into a cylindrical powder by centrifugal force, the heat source inserted into the center while the heat-resistant cylindrical body is rotated by the drive system is heated from the central region side and melted and integrated. By doing so, a heat-resistant fine powder or heat-resistant fiber is dispersed in the entire area to form a hollow quartz glass body.

"Operation" The present invention, for example, even when using a synthetic quartz glass having a high purity, which is easily softened at around 1150 ° C, heat-resistant fine powder such as silicon, carbon, or silicon carbide in the quartz glass at a predetermined ratio. It was focused on the fact that the apparent viscosity is improved by dispersing it, and by doing so, it is possible to obtain a quartz glass body that has sufficient heat resistance strength even in a high temperature atmosphere of around 1300 ° C and does not easily deform. Can be done.

Further, since silicon, silicon carbide and the like have different thermal expansion coefficients as compared with quartz glass as described above, when they are enclosed in a core like the prior art described above, the difference in thermal expansion coefficient is naturally. However, since the heat-resistant material is finely pulverized or made into fibers and dispersed integrally in the quartz glass body, the degree of expansion of the powder body or the fiber body itself is caused. Is so small that it can be ignored, so there is no risk of cracks or the like occurring on the quartz glass side.

In this case, if the particle diameter of the powder body or the wire diameter of the fibrous body is too large, or if the dispersion ratio of the powder body or the fibrous body becomes large, cracks or the like may occur on the quartz glass side. Alternatively, it is preferable that the dispersion ratio of the fibers is 5% by weight or less and the particle size thereof is 100 μm or less. Further, when the dispersion ratio of the fine powder or fiber is 0.01% by weight or less, the dispersion effect of the fine powder or the fibrous body is reduced, the heat resistance strength in a high-tone atmosphere is reduced, the dispersion ratio is 0.01. ~ 5
It is good to set to the weight percent. It is preferable that the fine powder is formed in a spherical shape having no protrusions as much as possible in order to prevent cracking of the quartz glass due to thermal expansion.

Further, since silicon, silicon carbide and the like are not semiconductor poisons which adversely affect the formed film on the surface of the wafer, the product yield does not decrease even when the dispersed portion is exposed on the surface.

Therefore, although it is possible to form the dispersion portion over the surface layer, the inside or the entire area of the quartz glass body according to the desired quartz jig, the above effect of increasing the heat resistance strength is smoothly achieved. In order to achieve this, for example, in the case of a quartz body formed in a shaft shape or a cylindrical shape, it is necessary to extend the dispersion site along the axial direction, and in the case of a hemisphere or a plate body, along the surface direction thereof. is there.

Further, since the dispersion portion is integrated with the quartz glass body, it is naturally easy to weld and heat-process, and a jig having a complicated shape or a large jig can be formed without impairing heat resistance.

Further, as shown in the examples below, the dispersion portion may be formed not only as a solid substance but also as a porous material having a large number of minute voids by selecting a manufacturing method.

"Example" Hereinafter, a quartz glass body according to an example of the present invention will be described based on a manufacturing method.

However, the material of the components described in this example,
Unless otherwise specified, the mixing ratio and the like are not intended to limit the scope of the present invention thereto, but are merely illustrative examples.

First, a high-purity hollow cylindrical quartz glass tube 12 is manufactured based on a known synthesis method, and then one end side thereof is sealed and the following mixed powder 13 is filled from the other end side.

The mixed powder 13 to be filled inside is silicon carbide Si whose particle size is adjusted to about 5 to 80 μm in high-purity synthetic quartz glass powder.
Prepare a mixture formed by uniformly mixing C powder in an amount of 1 to 2% by weight, 5% by weight, and 10% by weight, respectively.

The quartz glass tube 12 filled with the mixed powder is
As shown in FIG. 3B, both ends are supported by using a heat resistant support member 16, and a decompression device 17 is connected to the opening side of the quartz glass tube 12. And slowly rotate the quartz glass tube 12,
While heating the quartz glass tube 12 end side to around 2000 ° C. by the oxygen-hydrogen gas burner 15 while depressurizing from the depressurizing device 17, the one end side is stretched and stretched through the heat resistant support member 16, A quartz glass rod 1A having a reduced diameter is formed.

Looking at the cross-sectional structure of the quartz glass rod 1A thus formed, the porous glass heat-resistant dispersion portion 11 in which the SiC powder 2 is evenly dispersed is integrally formed in the quartz glass tube 10. Was confirmed.

Further, in the same manner, even when using a silicon carbide SiC fiber having a wire diameter of 5 to 80 μm instead of the silicon carbide SiC powder,
Similarly, when the cross-sectional structure of the quartz glass rod was observed, it was confirmed that a porous heat-resistant dispersion portion in which SiC fibers were uniformly dispersed was integrally formed in the quartz glass tube.

Next, five quartz glass rods 1A each containing 1 to 2% by weight, 5% by weight, and 10% by weight of SiC powder in the dispersion part 11 were heated in a heating furnace at 1300 ° C. for 10 hours, and then at room temperature. (About 20
After repeating 10 times the cycle of gradually cooling to (° C) and again heating in a heating furnace at 1300 ° C for 10 hours, about 10% by weight of the quartz glass rod 1A contained 2 out of 5 cracks. Things have been confirmed.

Next, 1 to 2 wt% of SiC powder with a particle size of 110 to 150 μm is dispersed and mixed, heated in a heating furnace at 1300 ° C for 10 hours, then slowly cooled to room temperature (about 20 ° C) and heated again to 1300 ° C. When the cycle of heating for 10 hours in the furnace was repeated 10 times, it was confirmed that all the quartz glass rods 1A had cracks.

FIG. 2 shows a method for producing a solid quartz glass body 1B in which the SiC powder 2 is dispersed over the entire area. As shown in FIG. 2 (b), silicon tetrachloride SiC ₄ is burned with an oxygen-hydrogen flame. By a VAD method using a burner 21 and a burner 22 that burns the SiCl ₄ with a carbon monoxide-oxygen flame, a SiO ₂ —SiC mixed soot body is formed while adjusting the supply amounts of the raw material gas and the combustion gas and passes through a heating source. By doing so, it is possible to manufacture the solid quartz glass body 1B shown in FIG. In this case, the dispersion ratio of the SiC powder 2 can be freely adjusted by adjusting the combustion amount of the burner 22 that burns SiCl ₄ with a carbon monoxide-oxygen flame.

Therefore, the dispersion ratio of the SiC powder 2 is 0.5%, 0.05%, 0.00
We made 5% quartz glass body 1B that does not disperse at all and manufactured a vertical boat using each quartz glass body and actually loaded a 5 ″ wafer in a heating furnace at 1300 ° C. for 120 hours. When the degree of deformation of the wafer holding part was observed by heating, the wafers with the SiC powder 2 having a dispersion ratio of 0.005% and those not dispersed at all were deformed so much that they could not be taken out from the holding part. Dispersion ratio is 0.5%, 0.
It was confirmed that the effect of 05% was remarkably improved, as the degree of deformation was extremely small and there was no problem in taking it out from the holding part.

FIG. 3 shows a method for producing a hollow quartz glass body 1C in which the SiC powder 2 shown in FIG.
Briefly explaining the constitutional action with reference to FIG. 2B, quartz glass powder, silicon carbide SiC powder or silicon carbide SiC fiber is uniformly applied to the inner surface of the heat-resistant cylindrical body 31 rotated by the drive system 30. The mixed powder is blown by a centrifugal force into a cylindrical powder 32, and then the heat-resistant cylindrical body 31 is rotated by the drive system 30 and heated from the central region side by the heating source 33 inserted in the central part to melt and integrate. Can be easily converted into SiC
It is possible to manufacture a hollow quartz glass body 1C in which the powder 2 is dispersed all over. Incidentally, 34 is a power source.

Further, the dispersed silica glass body can be easily formed by other silica glass manufacturing methods such as a sol-gel method using a metal alkoxide as a starting material.

[Advantages of the Invention] As described above, according to the present invention, it is possible to form a quartz glass body that does not have sufficient heat resistance strength and deformation even in a high temperature atmosphere of about 1300 ° C., and that cracks due to thermal expansion do not occur. , The dispersion site being present only in the central region according to its use (the invention according to claims 1 and 3),
In addition, it is possible to manufacture those existing in the entire area (the inventions according to claims 2, 4 and 5), and also those having a porous shape or a solid shape.

Further, since the dispersed parts are integrated as a quartz glass body, heat processing and welding are easy, and as a result, a jig having a complicated shape can be easily manufactured.

Further, when silicon, carbon, or a compound thereof is used as the fine powder dispersed in the quartz glass body, it does not become a semiconductor poison, so that the product yield does not decrease.

And so on.

[Brief description of the drawings]

1 (a) (b) to 3 (a) (b) are schematic views showing a quartz glass body manufacturing apparatus according to an embodiment of the present invention and a quartz glass body manufactured by the apparatus. is there.

Claims (4)

(57) [Claims] 1. A quartz glass body used for manufacturing a semiconductor manufacturing apparatus or a jig, at least one side of which is exposed to a high temperature, wherein heat-resistant fine powder or heat-resistant fibers are dispersed in quartz glass powder at a predetermined ratio. A quartz glass body, characterized in that the dispersion, which is a melt of the mixed powder, is located on the center side, the high-purity quartz glass is located on the surface layer side, and both are integrally fused. 2. A method for manufacturing a quartz glass body used for manufacturing a semiconductor manufacturing apparatus or a jig, at least one surface of which is exposed to high temperature, wherein a heat-resistant fine powder or heat-resistant fiber is placed in a high-purity quartz tube. Heat-stretched in a state where the mixed powder dispersed at a predetermined ratio in the quartz glass powder is filled, and high-purity quartz glass located on the surface layer side, and a dispersion which is a melt of the mixed powder located on the center side. A method for producing a quartz glass body, characterized in that the above are integrally fused. 3. A method for manufacturing a quartz glass body used for manufacturing a semiconductor manufacturing apparatus or a jig, at least one surface of which is exposed to high temperature, wherein silicon, carbon, or a compound thereof and SiO _{2 are used.}
Forming a mixed soot body consisting of, and passing the mixed soot body through a heating source to form a quartz glass body in which the heat-resistant fine powder or heat-resistant fiber made of the above-mentioned silicon, carbon, or a compound thereof is dispersed in the entire area. A method of manufacturing a quartz glass body, which comprises: 4. A method for manufacturing a quartz glass body used for manufacturing a semiconductor manufacturing apparatus or a jig, at least one surface of which is exposed to high temperature, wherein quartz glass is formed on an inner surface of a heat-resistant mold body rotated by a drive system. A heat source that is formed by spraying a heat-resistant fine powder or a mixed powder of heat-resistant fibers uniformly into a powder by a centrifugal force to form a cylindrical powder, and then inserting the heat-resistant cylindrical body in the center while rotating the drive system. A heat-resistant fine powder or heat-resistant fibers are dispersed in the whole area to form a hollow quartz glass body by heating from the central region side and melt-integrated, thereby producing a quartz glass body.