JPS58161981A - Manufacture of silicon nitride-clad ceramic base material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a method of manufacturing a ceramic substrate coated with electrified silicon. [Technical landscape of the invention and its points of interest] The molded body of Kaihua silicon has a heat resistance temperature of 1900°C.

[0], it can be produced relatively easily and easily, and has excellent heat shock resistance and chemical stability. High hardness, A
- Since it has excellent properties such as good insulation properties, it is widely used in gas transporting vibrators, crucibles for semiconductor baths, containers for crystal growth, and high-temperature mechanical parts. Generally, silicon nitride molded bodies are manufactured by the methods shown in (1) and (2) below. (1) MgO1A in electrified silicon (steN4) powder
JL Os + G A few sintering aids such as tOH
Blend - under normal pressure or pressurized atmosphere, 1700 to 20
Q sintered at 1aLM of 00 ("O) or filled with the above composition into the wrinkles of graphite, pressure 200-400
(&, 9/cd), 1700 ~ tsoo ('O'l). , hydrogen and ammonia are heat-treated in a mixture of nitrogen, hydrogen, and 01 gas at a temperature of about 1400 ('O)'' to nitride the metallic silicon of the molded body (reactive sintering method). The silicon nitride molded body obtained by method 1 has 3 ゜ of the sintering aid on each side as an impurity as described above, so it cannot be used as a high-purity container in an S-type container, such as a crucible for melting germanium or silicon semiconductors. In addition, the silicon nitride molded body obtained by the second method has a relative wj degree < m-density &3.1811
It has a porous structure with a low phase and sealing wax) of 85 to 60 [u], making it unsuitable for applications that require high density, such as corrosive gas transport pipes in crucibles for molten metal.
Ru. In addition, in order to remove impurities from a silicon nitride molded body, a purity treatment is usually performed in which the molded body is cleaned with hydrogen chloride, chlorine, etc. perpendicular to the III axis using a gas or wet method.
In this case, in order to perform high-purity treatment to the inside of the molded body, it is essential that the molded body has 411 pores. Therefore, the high purity of the material obtained by the first method is uniform. Therefore, in order to solve the above-mentioned problems and obtain an electrified silicon molded tube that retains the original characteristics of electrified silicon, a method has been proposed in which the surface of the ceramic is covered with a dense silicon nitride layer. In this case, the silicon nitride Jllri, 800~
A 3-component mixed gas of 1 bulk tetrachloride (St (J4), or silicon hydride (sta4), 2 hydrogen, and ammonia) was brought into contact with the surface of the porous valued silicon molded body heated to a temperature of 1400 ('O). The dense silicon nitride layer thus obtained is formed by a chemical vapor deposition method (CVD method) in which Sl.
It does not contain any impurities and is extremely thin. However, this type of method has the following drawbacks. That is, when the pre-articulated W negative silicon layer is formed from the α- or β-melon crystal phase, the f! The bonding force between the surface and the silicon nitride layer is weak,
As a result, there is a risk that the dense silicon nitride layer may peel off from the ceramic lI surface.In addition, if the formed dense silicon nitride layer is amorphous, the bonding force with the ceramic lI surface is strong. However, when the material is put into practical use, problems arise.For example, when used as a crucible for melting silicon semiconductors, the densified atomized silicon is corroded by the silicon melt, and the mechanical strength of the crucible deteriorates. [Objective of the Invention] The object of the present invention is to strengthen the bonding force between the dense silicon nitride layer and the Cefix surface when producing a ceramic base material coated with silicon nitride. It is an object of the present invention to provide a method for producing a ceramic base material coated with nitrogen nitride, which has excellent corrosion resistance and improved corrosion resistance. [Summary of the Invention] This invention produces a silicon nitride value-reduced ceramic base material, and the surface of the ceramic has a density of 9! Coating with high quality, non-contaminated silicon nitride, for example, using the CVD method, coating the ceramics with high quality amorphous silicon nitride at a temperature of 1000 to 1200 ('0) in a non-containing atmosphere containing ViIg. After removing the thin film, place III on the cough thin film! L-density negative Shao crystal negative silicon nitride coating, such as the above and lI! This is a method in which a thin film of dense crystalline silicon nitride is formed on the silicon nitride thin film at a temperature of 1200 to 1500 C''0) using IJ's CVD method. However, you can translate it appropriately depending on the purpose. In general, electrified silicon, aluminum nitride, silicon dispersion, aluminum oxide, zirconium oxide, carbon, sintered body of electrified element, etc., or quartz W The various sintered bodies mentioned above are preferably made of glass or the like, but the various sintered bodies mentioned above are not necessarily dense bodies, and may be formed from porous bodies.In addition, in the CVD method, the above-mentioned ceramic substrates are placed in a closed reactor. The next layer is stored, and the ceramic is heated to 1000 to 1200 ('O
'3, and then silicon tetrachloride or water volumized silicon,
Reactant gas containing nitrogen and ammonia
As a result, 51 mN4 is generated as a reaction product, and this S 1 s N4 is ceramic #! The heat treatment f! degree is xo
In oo('c)gh, the reaction is rapid and does not overfill, and 12
If it exceeds 00 ("O), crystalline silicon nitride will be formed and the bonding force with ceramics will be weakened. The thickness of the amorphous silicon nitride to be formed is not particularly limited, but it is between 1000 and 10 μm. Next, the ceramic is heated to 1 degree in the reaction vessel.
200-1500 [℃], preferably 1300-145
The temperature is raised to a range of 0 ('O), and the above reaction gas is introduced. Due to this, 811N4 is produced as an anti-46 product, and this 5isNa permeates the ceramic surface to form a crystalline silicon nitride layer. Here, the sword Ω heat treatment once is 120
0] or less, Ti amorphous silica is formed, leading to deterioration of corrosion resistance. Furthermore, the thermal expansion after heating is 1500 ('O)
When bonito is cooked, the whiskers are suppressed by the formation of vertical beams of small crystals in the six-dimensional structure. Causes deterioration. [Effects of the Invention] According to the present invention, dense amorphous IX is formed on the surface of ceramics.
Since a silicon nitride layer is formed, the bonding force between the silicon nitride layer and the seven foxes is sufficiently strong.Furthermore, a dense crystalline silicon layer is formed on the surface of the electrified silicon layer. So,
The bonding force between each silicon nitride layer is extremely large, and this makes it possible to sufficiently increase the bonding force between the dense noble crystal noble silicon nitride layer and the ceramic. Therefore, there is no risk of peeling between the ceramic and each of the silicon nitride layers, and the heat attack resistance can be improved. Moreover, the entire table Ifi is 17 itv! Since it becomes a crystalline silicon nitride layer, it has effects such as improved corrosion resistance. [Embodiments of the Invention] Hereinafter, the first to sixth embodiments that apply the present invention 1 will be explained. =3
A sintered silicon nitride plate (ceramics) 1 with a diameter of 0 (m) and a height D = 6 [■] was prepared. A smooth lead plate (not shown) was pressed onto one side of the sintered silicon nitride plate 10. , CVD these
It was placed in a reactor. Then hydrogenation ii bulk, ammonia and nitrogen 3ji! once at 1150(1))! Separate reaction gas (volume ratio of silica hydride lA = ammonia dielectric volume =
3:4:8) was uniformly flowed into the reactor for 60 minutes. As a result, the WM graphite plate of the silicon nitride sintered plate 1 is not pressure-welded. []K% As shown in FIG. 2, a dense silicon nitride layer 2 with a thickness of about 1 f) was formed. Next, at a temperature of 1350 °0, the three-component yarn reaction gas was passed through at the same volume ratio for 6 hours.
As shown in the figure, about 700 [μm] on the first silicon nitride layer 2.
An island 2 of silicon nitride'lA layer 3 having a thickness of 2 was formed. Fitting surface of the thus obtained hardened silicon-covered ceramic base material
Elemental analysis of the -5iL portion by a well-known method revealed that S
Furthermore, X-leg diffraction confirmed that it was α-type, that is, the silicon nitride layer 3 of ag2 was crystalline. In addition, in the first half of the process, phase fi-j le 1inl 150 ('O)
When K off CVD was performed separately and the formed dense part was subjected to elemental analysis, it was confirmed that it was Sl and N4. Furthermore, when this nt-x m diffraction was performed, no diffraction line of the crystal phase was observed.
was confirmed to be amorphous. Next, 50 sheets of silicon nitride laminated horizontal ceramic substrates prepared by the method described above were prepared, and a 0 thermal shock 1c test was performed in which each molded body was rapidly heated to 1000 ('0) K. After that, the rapid heating-quick cooling cycle is carried out for 5 times.
This is done 0 times, and at this time, the dense part (silicon nitride layer 2.
3) A method of fixing damage and peeling at the interface between ceramics 1 and ceramics 1 was used. The results are shown in the first diagram. For comparison, the gvB crystalline layer formed by the conventional CVD method also showed 1W1.
A similar test was conducted and the results are also listed. Table 1 From this table as well, the characteristic effects of the example base materials are clear. <Example 2> Baked in the same manner as in Example 1) with outer diameter of 80 [simplified],
A burnt MN silica crucible with an inner diameter of 70°, a depth of SO (simple), and a wall thickness of 5° was prepared. This crucible was placed in a heating furnace and heated to 1150° (O). Chlorinated wood 1 (%) + m volume 99 [%] of gas was properly placed in the same furnace and treated under the conditions of heating for 5 hours.Next, using the CVD method in the same manner as in Example 1, A dense amorphous electrified silicon layer with a thickness of 200 μm was formed on the inner wall surface of the crucible, and a dense crystalline silicon nitride layer was further formed with a thickness of 700 μm on the li! surface. The thus obtained crucible 51- was washed again with hydrofluoric acid (1:3 in volume ratio of hydrofluoric acid:@m) for 1 minute and used to improve the color of a metallic silicon single crystal, with good results in both cases. On the other hand, as a comparative example, one of the crucibles was
On one side, only 9 layers of nearly dense amorphous silicon are formed using the CVD method.
When 5 pieces formed with a thickness of 0.00 [Kishuma] were cleaned using the above method and then subjected to rice pulling for Kinkei silicon single crystals, 4 of them leaked due to poor corrosion resistance. . Furthermore, when 5 pieces of a crucible in which only a dense crystalline silicon nitride layer was formed to a thickness of 900 μm on the inner surface of the crucible in the same manner as above were used for pulling a cleaned metal silicon single crystal. Four of the seven beams and two leaked fluid. Example 3 An aluminum oxide sintering machine having the same dimensions as the silicon nitride sintered plate of Example 1 was prepared. Next, in the same manner as in Example 1, a dense amorphous silicon nitride layer with a thickness of 200 μm was formed on the aluminum oxide sintering process, and a layer of 700 μm thick was formed on the surface of this silicon nitride layer. A thermal shock test was conducted on 20 substrates each having a #ik-quality crystalline IX silicon nitride layer formed thereon. The thermal shock test was conducted on each ceramic substrate at 250 ('O)
A rapid heating-quenching cycle was performed 50 times, in which the sample was rapidly heated to a temperature of 100% and then taken out into the atmosphere, using the same rc@ detection method as in Example 1. The results are shown in Table 2. For comparison, a similar test was conducted on a sample in which a dense crystalline layer was formed by the conventional CVD method, and the results are also shown. Summary 2 Table <Example 4> A boron nitride sintered plate having the same dimensions as the silicon nitride sintered plate of Example 1 was prepared. Next, in the same manner as in Example 1, a dense crystalline silicon nitride layer of 200 [μm] was formed on the surface of the electrified boron sintered plate.
700 μm on the surface of this silicon nitride layer.
A base material on which a dense crystalline silicon nitride layer was formed with a thickness of 20
I conducted a thermal shock test on the sheet fJP. The thermal shock test involved heating each ceramic substrate to 1000 (O)K and then performing a rapid heating-quenching cycle 50 times, using the same observation method as in Example 1. The results are shown in Table 3.For comparison, a uniform test was also conducted on a material in which a dense crystalline layer was formed by the conventional CVD method, and the results are also listed. Print <Example 5> Same as Example 2, on tsI and outside diameter 80 [■],
A sintered carbon crucible with an inner pole of 70 cm, a depth of 80 cm, and a wall thickness of 5 cm was prepared. This crucible was placed in a heating furnace and heated to fL1150 ('O')C, and the gas of chloride water turbine 1 [shi] 10 nitrogen 99 [many] was passed into the furnace and heated for 5 hours to achieve high purity. The counterfeit was processed. Next, using the same CVD method as in Example 2, dense amorphous silicon nitride 1- is formed on the inner wall surface of the crucible to a thickness of 200 μm, and dense crystals are further formed on the & surface. A silicon nitride layer with a thickness of 700 μm was formed. Five of the crucibles thus obtained were washed again with fluoronitric acid (1:3 in the ratio of 1:3) for 1 minute, and then used for pulling the metal silicon single crystal. It showed good results. On the other hand, five specific soft ψIJs were prepared by forming only a dense amorphous silicon nitride layer with a thickness of 900 μm on the inner wall surface of the crucible by the KCVD method in the same manner as above, and after cleaning them by the above method). When used to protect metal silicon single crystals, four of them had poor corrosion resistance and leaked. Furthermore, six pieces of dense crystalline silicon nitride layers with a thickness of 900 [μ islands] formed on the inner surface of the crucible in the same manner as above were cleaned and then used for pulling up metal silicon single crystals. In four out of seven cases, cracks caused people to leak. <Example 6> Example 2 and Mr. M have an outer diameter of 80 [■] and an inner diameter of 70 (II
B) A quartz crucible with a wall thickness of 5 [■] was prepared. ◎Put this crucible into a heating furnace.
L11SO('O)K was sent out and the chloride book fil [u]◆-
Then, Example 2 and uniform KC
Using the VD method, dense amorphous electrification i! A base layer is formed with a thickness of 200 (x), and further
700 [#+1110] dense crystalline silicon nitride layer on Sayama
It was formed with a thickness. After washing the thus obtained crucible 5II with resaka fluorinitrate (volume ratio 弗#t: nitratetsuchu 1 = 3) for 1 minute, metal silicon single crystal 0! Good results were obtained for H, ξ, -. On the other hand, as a comparative IR example, five crucibles in which only a dense amorphous silicon nitride layer was formed by the CVD method to a thickness of 900 [Koejima] on the inner wall surface of the crucible were subjected to JjfIF and cleaning by the above method. After that, metal silicon 105
When subjected to 111 tests, four of them had poor corrosion resistance and leaked. In the same manner as above, only the 11thiK dense crystalline silicon nitride layer in the crucible was heated to 9Go.
It was formed with a thickness of Cμ! When s pieces were washed and subjected to pulling of metal silicon single crystals, 4 of them were
In some cases, cracks occurred and leakage occurred. It should be noted that the present invention is not limited to the above-mentioned 11V embodiments, but can be implemented with considerable modification without departing from the spirit of the invention. For example, as the ceramic structure, other than those used in the examples, oxidized aluminum,
A sintered body of silicon dioxide, zirconium oxide, or the like may also be used. Furthermore, the means for forming the silicon nitride layer is not necessarily the CVD method.
Rather than coating the material with C@, it is sufficient to use a method that allows coating the amorphous material first and then the crystalline material. Furthermore, it goes without saying that the temperature, treatment time, etc. during the heat treatment may be determined as appropriate depending on the specifications. 4.i! Figures 1 to 3 are perspective views showing the manufacturing process of an electrified silicone-coated base material according to an embodiment of the present invention. 1.・Silicon nitride sintered plate (Ceramittas), !1. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3

Claims (3)

[Claims] (1) A silicon nitride characterized in that the surface of the ceramic is coated with dense, amorphous electrified silicon, and then the surface of the amorphous silicon nitride is coated with dense, crystalline electrified silicon. A method for producing a ceramic base material. (2) As a means for coating each silicon nitride,
Claim No. 1, characterized in that the CVD method is used (
1) A method for manufacturing a silicon nitride-coated ceramitus base material. (3) The treatment temperature when coating the amorphous silicon nitride is 1000 to 1200 ('O), and the treatment mii* when coating the crystalline silicon nitride is 1200
1500 ('0), respectively. A method for producing a nitride-1-arsenic fused ceramic base material as described in item (1) or item (2) of the desired range of 'WffM.