JPS60215515A - Preparation of synthetic quartz mass and device therefor - Google Patents

Abstract

PURPOSE:To obtain foamless synthetic quartz mass in high yield, by feeding a volatile silicon compound and an oxygen gas at the center of a burner, feeding an oxygen gas and a hydrogen gas around the center, feeding a sealing gas at the outside. CONSTITUTION:A volatile silicon compound is fed from the inner pipe 16 of double pipe structure and an oxygen gas from the outer pipe 17 at the central part of a burner. An oxygen gas is fed from the pipes 18 set at symmetrical positions around the center, and a hydrogen gas is fed from the pipe 19 to gaps between the oxygen gas streams. At the outermost side, an inert sealing gas is fed the space between the double outer pipes 15 and 20. The burner having this structure is used, silicon dioxide fine particles are formed in an oxyhydrogen flame, they are jetted to the target base plate, synthetic quartz mass is melted and formed. By this method, attachment of the silicon dioxide fine powder to the outer pipes is eliminated, and occurrence of remaining foams in the quartz mass is extremely reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a 1i1 method for manufacturing negative quartz fiber, which is a raw material for semiconductor/mask substrates, optical lenses, etc., and an apparatus therefor.

Conventional technology and its disadvantages Conventional methods for producing synthetic quartz include gas-phase hydrolysis of volatile silicon halogens such as silicon tetrachloride in an oxyhydrogen flame, and the generated silicon dioxide wood particles are heated using combustion heat. The most common method of manufacturing is by blowing onto a rotating target substrate of quartz glass or q synthetic quartz glass heated to 1,800'C or higher and causing it to melt and grow.

According to the above method, J! ! By using synthetic quartz in the burner, it is possible to reduce the content of
, and the purity of the product is dramatically improved compared to when using conventional natural crystal as raw material.
The production of high-purity synthetic quartz blocks with few residual air bubbles has become an OT capability. However, when this synthetic quartz block is used for optical purposes, a small amount of remaining air bubbles causes defect scattering, which causes a decrease in light transmittance.

@Figure 1 is a schematic diagram of the entire device for implementing the above method, Figure 2 is fal, (b), and Figure 3 is fat, lb.
) are schematic diagrams showing conventional burners, respectively.

In Figure 1, 1 is a burner, 2 is a furnace lid, 3 is a furnace body, 4 is a monitoring window, 5 is an exhaust port, 6 is a furnace stand, 7 support rods, 8Fi support stand, 9 support rods, 10 is synthetic quartz The elementary mass, 11.13, is oxygen gas, 12 silicon tetrachloride, and 4 hydrogen gas. In FIGS. 2 and 3, id: 15 +- is an outer tube, 16 is an inner tube, 17 is an outer tube, 18 is an oxygen gas supply tube, and 19 is a hydrogen gas passage.

Purpose of the Invention The present inventors conducted research with the aim of reducing such residual air (ijl). Due to fluctuations in the internal pressure of the furnace, gas pressure, vibrations of the equipment, etc., fine particles of silicon dioxide adhering to the silica particles fell onto the molten surface of the 41. (Going to Step 1, it was determined that this is due to thermal expansion of the gas adhering to the coalesced surface of the fine particles as time passes.)

Therefore, in order to prevent fine particles of silicon dioxide, which is one of the causes of bubble formation, from adhering to the outermost wall of the quartz glass burner,
As shown in Figure 4, a burner was manufactured in which a sealing outer tube 20 was arranged vertically on the outside of an outer tube 15. A non-flammable gas such as clean air, oxygen, or argon is passed through this sealing outer cylinder 'If2 (), and the hydrogen gas flowing inside is wrapped around it to prevent natural diffusion of the hydrogen gas. When we produced a raw mass, we confirmed that there was no adhesion of silicon dioxide fine particles and the generation of residual air bubbles was drastically reduced.
The invention has been completed.

According to the structure of the present invention, that is, according to the production method of the present invention, volatile silicon compound and oxygen gas and oxygen gas and hydrogen gas are blown out from a gas burner to generate silicon dioxide fine particles in an oxyhydrogen flame. In the manufacturing method of synthetic quartz blocks, which involves spraying and melting growth on a rotating target base, a volatile silicon compound and oxygen gas are supplied in a double tube at the center of the burner, and around the Oxygen gas is supplied to the center in a symmetrical position, and hydrogen gas is supplied to the gap between the If elementary gas flows, and furthermore, an inert sealing gas is supplied to the outermost part in a double tube shape. According to the apparatus of the present invention, a method for producing a synthetic quartz block is obtained, which is characterized by using a burner that supplies volatile silicon compounds and oxygen gas, as well as oxygen gas and hydrogen gas. Receive the burner and generated silicon dioxide fine particles.

In an apparatus f for producing a synthetic quartz block, which includes a rotating target disk for producing a synthetic quartz block, a monopolymer silicon compound arranged in a double-tube structure at the center of the burner is placed in the center of the burner. A plurality of tubes arranged symmetrically with respect to the center of the burner are arranged in the space between the outer tube for supplying oxygen gas, the outer fl-!f, the nuclear outer g, and the nuclear outer segment tube 1111 provided surrounding the outer tube. Oxygen gas supply 'g and hydrogen gas jIt line means with a gap between the oxygen gas supply metering as a flow path and the outside of the pipe are provided,
A synthetic stone/A:51c block) manufacturing apparatus is equipped with a burner comprising a sealing outer tube through which an inert sealing gas flows between the outer tube and the outer tube.

As an example of the burner of the present invention, in FIG. There are no restrictions on the position or number of reaction gas supply pipes, and it is important that the outer cylinder '915 has a 21-pipe structure with the sealing outer cylinder pipe 2o. As shown in FIGS. 4 and 5, the tubes may be parallel to each other or may be inclined.

Various heat-resistant ceramics can be used as the material for the reaction gas supply pipe, but synthetic quartz is free from the risk of contamination with impurities, and if the tip becomes damaged due to long-term use, the tip can be cut and reused. This is suitable because it can also be used.

The gases flowing to each part of the reaction tube are normally supplied with oxygen gas from the reaction gas supply pipe, and hydrogen gas is supplied from the surroundings to ignite it. When the target substrate 9 reaches a predetermined temperature, the reaction gas supply from the center is carried out. Switch the tube from oxygen gas to a volatile silicon compound such as dichlorsilane or monosilane, or a silicon compound such as a hydride, generate silicon dioxide with an oxyhydrogen flame, and melt and deposit it on the base plate 9. In this way, a synthetic quartz block was produced. At this time, the inert sealing gas flowing into the sealing outer tube 20 is clean air,
Nitrogen% oxygen, helium, argon, etc. are preferable; if hydrogen is used, the adhesion of silicon dioxide particles to the outer tube 15 is reduced, but due to the action of hydrogen in a certain temperature range, the quartz outer tube 15 is This is undesirable because the tip deteriorates significantly (-), which shortens the life of the burner.According to the method of the present invention, hydrogen gas is trapped in the inert sealing gas and reacts completely with oxygen gas. It is estimated that this will occur.

As described above, the present invention provides a method and apparatus d for producing a synthetic quartz block containing no air bubbles, and its industrial value is extremely large.

Next, the present invention will be specifically explained using actual examples, but the present invention is not limited by the following embodiments unless it exceeds the gist thereof.

Example A synthetic silica glass ingot was manufactured using the transparent quartz burner shown in FIG. 4 (outer diameter of sealing outer tube 20: 80 i++w).

Oxygen gas -*a*0.
7 Oxygen gas in Nrn3/H1 reaction gas supply 117
ease O03Nm' /Hr reaction reaction gas pipe supply pipe 1
8 elemental gas 11111111 2.5 NIn'/)I
r Outer tube 15 around the reactant gas co-supply 18 ``''i4. o
Hydrogen gas in Nm, A (r (outer diameter 70 mm)) First, an oxyhydrogen flame is formed in the burner at the above flow rate, and after the rotating target base is sufficiently heated to the melting temperature button, the reaction gas is Rectified silicon tetrachloride gas was fed into the supply pipe 16 at an average rate of 1,700 g/Hr, and in a reaction time of 7 hours, a bullet-shaped synthetic quartz glass ingot of 3,150 g with an outer diameter of 100 inches and a height of 110 mm was produced. .

Ratio:l! Example 12 @ Figure 4 A synthetic quartz block was produced using a fat transparent quartz burner (outer cylinder, g15 outer diameter: 70 mm).

Oxygen gas in the reaction gas supply pipe 16... Bone O-7N
ma Al into the reaction gas supply f17 with oxygen gas...
... 0.3 Nm"/■r Reaction gas supply pipe 18 internal gas ... 3.5 Nm" /) (rHydrogen gas in the outer cylindrical pipe 15 around the above reaction gas supply pipe 18 ...
・] 5. ONm4(r) First, form an oxyhydrogen flame in the burner at the above flow rate.

After the rotating target base is sufficiently heated to the melting temperature, rectified silicon tetrachloride gas is fed into the reaction gas supply f]6 at an average rate of 1,1 (10, j/ /) (r). , reaction time 6:1141, outer diameter 90 mm, height 120 m
A bullet-shaped @-Nariishi capsule east 1.1110.11' of m was sown. Comparison E was made as follows for the combination Jzk stone key element 1 obtained in the FII 3 actual example and the comparative example.

First, with regard to air bubbles, approximately 1() of each size was introduced into the sample of the comparative example by parsimony by adding %l''. On the other hand, no bubbles were observed in the sample of 1 case, and the sealing outer cylinder tube was hot, hot and dry.

Regarding the strained veins, Mitsubishi Sake 118-tillL/
~Using strain test 4, 54! Leprosy and comparison $+1
Each sample was examined, but nothing was found.

As mentioned above, after one use of the sealing outer cylinder g, the adhesion of the silicon dioxide imitation to the outer cylinder "U" disappeared completely, and as a result, air bubbles were sometimes observed in the synthesized quartz bulk. Well, we were able to achieve a modest improvement in yield to IJ.

[Brief explanation of drawings]

Figure 8g1 is a schematic diagram of a general synthetic quartz block manufacturing device, and Figure 2ial is a cross-sectional view of an example of a conventional burner.
+1311d A sectional view taken along line A-A of fal, Figure 3 ial is a cross-sectional view of another conventional burner, the same <(b) is a BB sectional view of fal, and Figure 4 ial is a cross-sectional view of an actual case of the present invention. Cross-sectional view of the burner, same < (b) is ta) υ) C-C cross-sectional view, Fig. 5 fa) k Cross-sectional view of the burner of another embodiment of the invention, same 1]-D sectional view of if;+l. In the figure: ]...-Base 11.13-...Oxygen gas supply pipe 2...Furnace lid 12...Volatile silicon compound supply pipe 3...Furnace body 7°°° ° Support salary 17... Outer tube (Oxygen gas 8... Support stand supply pipe) 9 -----, [l? J base 18...Oxygen gas supply pipe] ()...Synthetic quartz block 19°---Hydrogen"X4 path 20...Outer tube for sealing 2100 Inert sealing gas (a-) $31 (b) ■Purchase U /6 /A, (a-9

Claims (1)

[Claims] 111 Volatile silicon compound and oxygen gas as well as oxygen gas and hydrogen gas are blown out from a burner to generate silicon dioxide fine particles in an oxyhydrogen flame, and the silicon dioxide fine particles are blown onto a rotating target base. In the manufacturing method of synthetic quartz blocks, which involves attaching, melting, and growing, a volatile silicon compound and oxygen gas are supplied in a double tube form at the center of the burner, and around the burner, volatile silicon compounds and oxygen gas are supplied at symmetrical positions with respect to the center of the filament. Synthetic quartz characterized by using a burner that supplies oxygen gas in a double tube shape at the outermost side, supplies hydrogen gas in the gap between the oxygen gas flows, and further supplies inert sealing gas in a double tube shape at the outermost side. Manufacturing method of raw blocks. (2) In a synthetic stone quartz production device comprising a volatile silicon compound and oxygen gas, a burner that blows out oxygen gas and hydrogen gas, and a rotating target base that receives the generated silicon dioxide X fine particles and converts them into a synthetic quartz block, An inner tube for supplying a volatile silicon compound and an outer tube for supplying lv gas arranged in the center of the burner in a double-layer structure, and an outer cylinder tube provided surrounding the outer core. and the outer cylinder quality + f, tff
A plurality of oxygen gas It-supply pipes are arranged in a space symmetrically with respect to the center of the burner, and a hydrogen gas supply means with a gap P between the oxygen gas supply pipes as a flow path, and a nuclear outer segment pipe. 1. An apparatus for producing a synthetic quartz block, characterized in that it is equipped with a bath consisting of a sealing outer tube provided on the outside and inert sealing gas flowing between the outer tube and the outer tube.