JPH07249587A - Member for liquid phase epitaxial growth and its manufacturing method - Google Patents

Abstract

PURPOSE:To obtain a member for liquid phase epitaxial growth without causing an impurity adsorbed inside to appear on the surface by eliminating an open pore by forming polycarbodiimide resin with a high carbon content after baking carbonization for carbonization to form a glass-shaped carbon. CONSTITUTION:A boat member 1 for liquid phase epitaxial growth device, a slider 2, and a boat lid 3 are created as follows. Namely, polycarbodiimide resin liquid solution is injected into each corresponding metal mold, is formed at 60 deg.C for 20 hours and 120 deg.C for 10 hours, and then is taken out of the mold. After that, it is heat-treated at 200 deg.C for 10 hours, thus carbonizing resin. Round holes 4 are punched at two locations in the boat member 1 and at the same time a space 5 for inserting the slider 2 is provided near the bottom surface, thus eliminating the round holes 4 of the boat member 1 and preventing the run-off of a liquid solution in the round hole 4 by the slider 2. Also, the slider 2 is in 15 mm (Width) X 200m (Length) X 3mm (Thickness) and a recess 6 for receiving a single crystal is provided on it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a member used for liquid phase epitaxial growth of a compound semiconductor (using indium, gallium, arsenic and phosphorus) and a method for manufacturing the member. No pores,
The present invention relates to a member for liquid phase epitaxial growth represented by boats, sliders and other jigs, in which no separation of powder is observed, and a method for manufacturing the member.

[0002]

2. Description of the Related Art Liquid phase epitaxial growth is a kind of thin film growth technique in the manufacturing process of semiconductor devices, and is a method of growing a thin film directly on a semiconductor substrate using a supersaturated melt such as gallium.

In the slide boat method, the apparatus for the liquid phase epitaxial growth is composed of a boat for inserting a supersaturated melt, a slider for moving a semiconductor substrate, and other jigs. These boat, slider and Conventionally, graphite having high purity and high density has been used for other jigs.

[0004]

However, although the above graphite has the characteristics of high thermal conductivity, high purity, high thermal shock resistance, and low reactivity with metals, its surface has Since there are open pores, there is a problem that impurities are adsorbed or phosphorus or arsenic enters, and these come into contact with the growth film during liquid phase epitaxial growth, which deteriorates the characteristics of the epitaxial film.

[0005] Further, graphite further has a defect that the graphite powder is easily detached from the surface, but this graphite powder has also been a cause of deteriorating the characteristics of the epitaxial film.

From the above, pitch obtained by incompletely pyrolyzing an organic polymer (vinyl chloride) is mixed with an aromatic solvent to form a slurry, and the slurry is appropriately molded by a graphite material department. It has been attempted to coat the molded product with glassy carbon to prevent the generation of graphite powder by, for example, a method of applying it to the product and then firing it (see Japanese Patent Publication No. 52-39684). According to the method, a thick coating could not be formed or a crack was generated, so that a sufficient effect could not be obtained.

The present invention solves the above-mentioned problems in the prior art, and is for liquid phase epitaxial growth represented by boats, sliders and other jigs, which has no open pores and no separation of powder is observed. It is made for the purpose of providing a member.

[0008]

The constitution of the member for liquid phase epitaxial growth adopted by the present invention to achieve the above object is characterized in that it is made of glassy carbon derived from a polycarbodiimide resin. Further, in order to achieve the above object, the constitution of the method for producing a liquid phase epitaxial growth member adopted by the present invention, a composition comprising a polycarbodiimide resin or a polycarbodiimide resin is molded into a liquid phase epitaxial growth member shape, Then, the molded product is carbonized.

That is, the inventors of the present invention pay attention to a polycarbodiimide resin which is a resin having a high carbon content after firing and carbonization and a high yield, and molding this resin into a member for liquid phase epitaxial growth. If carbonized and made into glassy carbon, I got the idea that a member for liquid phase epitaxial growth without open pores and without separation of powder could be obtained, and as a result of further research, The present invention has been completed.

The present invention will be described in detail below.

The liquid phase epitaxial growth member to be used in the present invention is mainly used in the slide boat method, and as described above, it includes a boat for inserting a supersaturated melt and a semiconductor substrate. It includes sliders and other jigs for moving, and these members are usually manufactured by processing graphite.

In the present invention, the member for liquid phase epitaxial growth is formed of glassy carbon derived from carbonized polycarbodiimide resin.

The above-mentioned polycarbodiimide resin itself is well-known, or can be produced in the same manner as well-known ones [US Pat. No. 2,941,95].
6, Japanese Patent Publication No. 47-33279, J. Or
g. Chem. , 28 , 2069-2075 (196
3) Chemical Review l98l, vo
l. 8l. No. 4, 619 to 62l, etc.}, for example, it can be easily produced by a condensation reaction involving decarbonization of an organic diisocyanate in the presence of a carbodiimidization catalyst.

The organic diisocyanate used for producing the above polycarbodiimide resin may be of any type such as aliphatic type, alicyclic type, aromatic type and aromatic-aliphatic type. Used alone, or
You may use it as a copolymer combining 2 or more types.

Thus, the polycarbodiimide resin used in the present invention has the following formula -RNN = C = N- (wherein R in the formula represents an organic diisocyanate residue).
The homopolymers or copolymers of at least 1 type of repeating unit represented by

As R in the above formula, which is an organic diisocyanate residue, an aromatic diisocyanate residue is particularly preferable (here, the organic diisocyanate residue is obtained by removing two isocyanate groups (NCO) from the organic diisocyanate molecule). I say the rest). The following can be mentioned as specific examples of such a polycarbodiimide resin.

[Chemical 1]

In each of the above formulas, n is 10 to 10,0.
It is in the range of 00, preferably in the range of 50 to 5,000, and the end of the polycarbodiimide resin may be blocked with monoisocyanate or the like.

The above polycarbodiimide resin can be obtained as a solution as it is or as a powder precipitated from the solution, and the polycarbodiimide resin thus obtained is a liquid obtained polycarbodiimide resin.
In the case of a polycarbodiimide resin obtained as it is or after distilling off the solvent, or as a powder, it may be used as it is or after being dissolved in a solvent to form a liquid.

In the present invention, a molded product in the shape of a member for liquid phase epitaxial growth represented by a boat, a slider and other jigs is first molded from the above polycarbodiimide resin or the polycarbodiimide resin solution. As a method for molding a molded article, a method generally used in such a step can be used, and there is no particular limitation, and examples thereof include injection molding, compression molding, cast molding, vacuum molding and the like. .

Next, the formed product formed in the shape of the member for liquid phase epitaxial growth as described above is heated to carbonize the polycarbodiimide resin into glassy carbon, whereby the target liquid of the present invention is obtained. A member for phase epitaxial growth can be obtained. This carbonization process
It can be carried out in an inert atmosphere such as vacuum or nitrogen gas, and the final firing temperature at that time is preferably 100.
It is 0 ° C to 3000 ° C.

The temperature rising rate up to the final calcination temperature in the carbonization step is preferably 2 ° C./hour or less, and when the final calcination temperature is reached too early, open pores are formed in the glassy carbon. It is not preferable.

As described above, since the obtained member for liquid phase epitaxial growth of the present invention is composed of glassy carbon derived from polycarbodiimide resin, there are no open pores found in graphite products, and Also, phosphorus, arsenic and other impurities do not enter inside. In addition, the bulk density is 1.51 to 1.8 g / cm compared to ordinary graphite materials.
Despite being as small as ² , the bending strength is 1800-40
00 kg / cm ² , Shore hardness of 121-140,
In addition, since it has a denseness (homogeneity) that there is no defective portion such as open pores, it is a good one in which cracks are not generated and the powder does not separate at all.

Next, the present invention will be described in more detail with reference to examples.

[0024]

【Example】

Example 1 Mixture of 2,4-tolylene diisocyanate / 2,6-tolylene diisocyanate (80:20) (TDI) 5
In 500 ml of tetrachloroethylene, 4 g of carbodiimidization catalyst (1-phenyl-3-methylphosphorene oxide) was added. A reaction was carried out with 12 g at 120 ° C. for 4 hours to obtain a polycarbodiimide resin solution.

Next, the board member 1, slider 2 and boat lid 3 for the liquid phase epitaxial growth apparatus shown in FIG.
Was created as follows.

That is, the polycarbodiimide resin solution is added to the board member 1, the slider 2 and the boat lid 3.
Were poured into metal molds (not shown) corresponding to the above shapes, molded at 60 ° C. for 20 hours and 120 ° C. for 10 hours, and then taken out of the molds. After that, heat treatment is performed at 200 ° C. for 10 hours, and this is heated at 2 ° C./hour in nitrogen for 2
The temperature was raised to 000 ° C. to carbonize the polycarbodiimide resin, and an example of the intended member for liquid phase epitaxial growth of the present invention was obtained. No pores were observed or measured on the surface of this product. The bulk density is 1.55 and the bending strength is 270.
The Shore hardness was 0 kg / cm ² and the Shore hardness was 130.

The boat member 1 has a total length of 75 mm and a width of 30 mm.
The round holes 4 of the boat member 1 are formed by providing the round holes 4 at two positions and the gap 5 for inserting the slider 2 into the boat member 1 near the bottom surface of the board member 1. , 4 has no bottom, and the slider 2 prevents the solution from flowing out of the round holes 4, 4.
The slider 2 has a width of 15 mm, a length of 200 mm, and a thickness of 3 mm, and a recess 6 for mounting a single crystal is provided on the slider 2.
Further, the lid 3 of the boat member 1 is a plate having a diameter of 15 mm.

Next, liquid phase epitaxial growth was carried out as follows using an example of the liquid phase epitaxial growth member of the present invention.

Metallic gallium was placed in the round holes 4 and 4 of the boat body 1 and the lid 3 was covered, and in the recess 6 of the slider 2, the gallium-arsenic substrate and the gallium-arsenic substrate for liquid phase epitaxial growth were placed. The slider 2 was adjusted so that the lower portions of the round holes 4 and 4 did not come into contact with any of the substrates, and the slider 2 was placed in a quartz tube to create a vacuum. Next, hydrogen gas was flown into the electric furnace to raise the temperature. When the gallium was melted, the slider 2 was moved to saturate the gallium-arsenic in the gallium-arsenic substrate, and then cooling was started. Next, the gallium-arsenic substrate for liquid phase epitaxial growth under the circular holes 4 and 4 is moved, cooling is continued, and
Arsenic was grown, and liquid phase epitaxial growth was performed three times under the same method and under the same conditions. The conductivity type, carrier concentration, mobility, carbon concentration and oxygen concentration of gallium-arsenic obtained by this method were measured. The results are shown in Table 1.

Example 2 A liquid phase epitaxial growth member having no pores on its surface was produced in the same manner as in Example 1 except that the temperature rising rate was 1 ° C./hour. No pores were observed on the surface of this product, the bulk density was 1.56, and the bending strength was 2700 kg / c.
The m ² and the Shore hardness were 130. Table 1 shows the results of use in liquid phase epitaxial growth in the same manner as in Example 1.

COMPARATIVE EXAMPLE A graphite material (specific gravity: 1.85) made by Toyo Tanso Co., Ltd. was used to form a member for liquid phase epitaxial growth similar to that in the above-mentioned embodiment.
Liquid phase epitaxial growth was performed three times under the same conditions as in the example. Gallium-arsenic conductivity type obtained by this method,
The carrier concentration, mobility, carbon concentration and oxygen concentration were measured. The results are shown in Table 1 (note that the conductivity types of the comparative examples are all p-type due to the influence of impurities in graphite).

[0032]

[Table 1]

[0033]

As shown in Table 1 above, since the member for liquid phase epitaxial growth of the present invention is made of glassy carbon derived from polycarbodiimide resin, the powder is separated from the surface or the member is made of graphite. Since phosphorus, arsenic, and other impurities that have penetrated into the interior and adsorbed do not come out on the surface, it is possible to create a good semiconductor with low carrier concentration, high mobility, and few impurities. is there.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional side view showing an example of a liquid phase epitaxial growth member of the present invention.

[Explanation of symbols]

 1 Boat member 2 Slider 3 Boat lid 4, 4 Round hole 6 Recess

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C30B 19/06

Claims (9)

[Claims] 1. A member for liquid phase epitaxial growth comprising glassy carbon derived from a polycarbodiimide resin. 2. The member for liquid phase epitaxial growth according to claim 1, which is a boat, a slider and other jigs. 3. The member for liquid phase epitaxial growth according to claim 1, wherein the glassy carbon is obtained by carbonizing a polycarbodiimide resin in a vacuum or an inert atmosphere. 4. The liquid phase epitaxial growth member according to claim 1, wherein the surface has no open pores. 5. A method for producing a member for liquid phase epitaxial growth, which comprises molding a polycarbodiimide resin or a composition mainly composed of polycarbodiimide resin into a shape of a member for liquid phase epitaxial growth, and then carbonizing the molded product. . 6. The method for producing a member for liquid phase epitaxial growth according to claim 5, wherein the member for liquid phase epitaxial growth is a boat, a slider and other jigs. 7. The method for producing a member for liquid phase epitaxial growth according to claim 5, wherein carbonization of the molded product is performed in a vacuum or in an inert atmosphere. 8. The carbonization of the molded product is 1000 ° C. to 300 ° C.
The method for producing a liquid phase epitaxial growth member according to claim 7, wherein the method is performed in a temperature range of 0 ° C. 9. The method for producing a member for liquid phase epitaxial growth according to claim 8, wherein the rate of temperature increase up to the carbonization temperature is 2 ° C./hour or less.