JP3154339B2 - Method for purifying germanium hydride - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for purifying germanium hydride, and more particularly to a method for purifying germanium hydride which can remove oxygen contained in germanium hydride as an impurity to an extremely low concentration. Germanium hydride is important as a raw material for manufacturing germanium semiconductors, etc., and its usage is increasing year by year.At the same time, with the advancement of semiconductors, extremely low impurity content is required. ing.

[0002]

2. Description of the Related Art In general, germanium hydride used in the production of semiconductors is commercially available in the form of pure germanium hydride, or diluted with a hydrogen gas or an inert gas and filled in a cylinder. These germanium hydrides include:
Oxygen and moisture are contained as impurities, of which moisture can be removed by a dehumidifier such as synthetic zeolite. The oxygen content in commercially available germanium hydride is usually 10 ppm or less, but a relatively low level of 0.1 to 0.5 ppm, such as recent bottled hydrogenated germanium, is also commercially available. There is almost no known technique for efficiently removing oxygen contained in germanium hydride.

[0003]

Recently, silane, arsine, phosphine, and hydrogen selenide used in the production of semiconductors can be purified to a high degree of purity. For example, oxygen contained as impurities has a purity of 0.01 ppm or less. Can be obtained. Therefore, germanium hydride having an oxygen content of 0.01 ppm or less is strongly desired. In addition, since these gases may be contaminated by impurities such as air during the supply process to the semiconductor manufacturing apparatus such as when connecting cylinders or switching pipes, it is desirable that these gases be finally removed immediately before the apparatus.

[0004]

The present inventors have conducted intensive studies to efficiently remove oxygen contained in germanium hydride to an extremely low concentration. As a result, germanium hydride was converted into nickel or copper germanium. It has been found that the oxygen concentration can be reduced to 0.1 ppm or less and further to 0.01 ppm or less by contact with a compound, thereby completing the present invention. That is, the present invention is a method for purifying germanium hydride, which comprises contacting crude germanium hydride with germanide of nickel or copper to remove oxygen contained in the crude germanium hydride. The present invention relates to germanium hydride alone, germanium hydride diluted with hydrogen (based on hydrogen gas) and an inert gas such as nitrogen or argon (based on inert gas) (hereinafter collectively referred to as crude germanium hydride). It is applied to the removal of oxygen contained in.

In the present invention, nickel germanide is Ge ₂ Ni ₅ , Ge ₃ Ni ₅ , GeNi ₂ , Ge
Nickel germanide commonly known as Gex Niy such as Ni, and germanium bonded to nickel in various other forms. In addition, the copper of germanium hydride such as Cu ₄ Ge, Cu ₃ Ge Cux
Copper germanide, commonly known as Gey, and germanium bonded to copper in various other forms. There are various methods for obtaining germanium hydride of nickel or copper. Among these, as a simple method, for example, germanium hydride can be easily obtained by contacting nickel or copper with germanium hydride. Nickel in this case may be metal nickel or a nickel oxide, and copper may be nickel or copper compounds which are easily reduced, such as metal copper or a copper oxide. Further, chromium, iron, cobalt, or the like may be used in a small amount as a metal component other than nickel or copper.

[0006] These nickel or copper can be used alone.
May be used, and also supported on a catalyst carrier or the like.
It may be used in the form
For the purpose of increasing the contact efficiency, etc., usually a catalyst carrier etc.
It is used in a form supported on. Nickel supported on carrier
As a method of causing the same, for example, in an aqueous solution of nickel salt
Diatomaceous earth, alumina, silica alumina, aluminosilicate
Dispersion of carrier powders such as calcium and calcium silicate
And further add alkali to add nickel to the carrier powder.
Precipitate the components, then filter and wash if necessary with water
After drying the obtained cake at 120 to 150 ° C, 300 ° C or more
And crush the baked product or use NiC
O_Three, Ni (OH)_Two, Ni (NO_Three)_Two Such as inorganic
Salt, NiC_TwoO _Four, Ni (CH_ThreeCOO)_TwoSuch as organic
After baking and crushing the salt, mix it with heat-resistant cement
And firing. These are usually
It is molded by extrusion molding, tablet molding, etc.
Is used by being crushed to an appropriate size if necessary.
As a molding method, a dry method or a wet method can be used.
In this case, a small amount of water, a lubricant, or the like may be used.

Further, as the nickel-based catalyst, for example, a steam conversion catalyst, C11-2-03 (NiO-cement),
11-2-06 (NiO-refractory), C11-2 (Ni
-Calcium aluminate), C11-9 (Ni-alumina); hydrogenation catalyst, C46-7 (Ni-diatomaceous earth), C
46-8 (Ni-silica), C36 (Ni-Co-Cr)
-Alumina); gasification catalyst, XC99 (NiO); hydrogenation shift catalyst, C20-7 (Ni-Mo-alumina) [all manufactured by Toyo CCI Co., Ltd.] and hydrogenation catalyst, N-11
1 (Ni-diatomaceous earth); gasification shift catalyst, N-174 (N
iO); various catalysts such as a gasification catalyst and N-185 (NiO) (both manufactured by JGC Corporation) are commercially available, and an appropriate one may be selected from these and used. There are various methods for obtaining copper oxides.For example, copper oxides are added by adding alkalis such as caustic soda, caustic potash, sodium carbonate, and ammonia to copper nitrates, sulfates, chlorides, and organic acid salts. , And the resulting precipitate is calcined. These are usually formed into a molded product by extrusion molding, tablet molding, or the like, and are used as they are or crushed to an appropriate size as needed. As a molding method, a dry method or a wet method can be used, and in that case, a small amount of water, a lubricant, or the like may be used. Further, since there are various types such as commercially available copper oxide catalysts, those selected from them may be used.

In short, it is only necessary that reduced nickel, nickel oxide, reduced copper, copper oxide and the like are finely dispersed and have a large surface area and a high contact efficiency with gas. The specific surface area of these nickel or copper catalysts is usually
In the range of 10 to 300 m ² / g by the BET method, it is preferably in the range of 30~250m ² / g. Also,
The content of nickel or copper is usually 5 to 95 wt%, preferably 20 to 95 wt% in terms of metallic nickel or copper.
%. If the content of nickel or copper is less than 5 wt%, the deoxygenation capacity is reduced, and 95 wt%
If it is higher than that, sintering may occur during reduction with hydrogen, and the activity may be reduced.

The conversion of nickel or copper to germanium can be usually carried out by bringing germanium hydride into contact with reduced nickel, nickel oxide, reduced copper, copper oxide, etc., but in the case of nickel oxide, copper oxide, etc. Reduced nickel or reduced copper may be previously obtained by hydrogen reduction. At the time of hydrogen reduction, for example, 350 ° C.
The linear gas velocity (LV) of the hydrogen-nitrogen mixed gas is about
It can be done by passing it at about 5 cm / sec,
Care must be taken to avoid a sudden rise in temperature due to the exothermic reaction. In addition, by performing the reduction with a hydrogen-based germanium hydride, germanium conversion can be performed at the same time, which is convenient.

[0010] Germanium conversion is generally carried out by filling nickel, copper or a carrier thereof with a carrier into a cylinder such as a purification cylinder, and passing germanium hydride or a gas containing germanium hydride through the cylinder. The concentration of germanium hydride used for germanification is usually 0.1% or more, preferably 1% or more. If the concentration of germanium hydride is lower than 0.1%, it takes time to complete the reaction, which is uneconomical. Although germanification can be performed at room temperature, it is an exothermic reaction, and the temperature is easily increased as the concentration of germanium hydride is higher.
It is preferable to adjust the flow rate of the gas so that the temperature is maintained at a temperature of not more than ℃. The end of germanium conversion can be known by a decrease in the calorific value and an increase in the amount of outflow of germanium hydride from the outlet of the cylinder. In the present invention,
Nickel or copper that has been converted to germanium may be filled in another purification cylinder again, and oxygen may be removed and purified through crude germanium hydride.However, germanium compounds are highly toxic and require careful handling. It is preferable that the germanium conversion be performed from the beginning in a germanium hydride purification column, and after the completion of the germanium conversion, the crude hydrogen hydride be subsequently supplied to carry out the oxygen removal purification.

[0011] Purification of germanium hydride is usually carried out by flowing crude germanium hydride through a purification cylinder filled with nickel or copper germanide.
Oxygen contained as an impurity in the crude germanium hydride is removed by the contact of the crude germanium with germanium nickel or copper. The oxygen concentration in the crude germanium hydride applied to the present invention is usually 100 ppm or less. If the oxygen concentration is higher than this, the calorific value increases, so a heat removal means is required depending on the conditions. The filling length of the nickel or copper germanium compound filled in the purification cylinder is usually 50 to 1500 in practice.
mm. If the filling length is shorter than 50 mm, the oxygen removal rate may decrease. If the filling length is longer than 1500 mm, the pressure loss may become too large. Vacancy linear velocity of crude germanium hydride during refining (L
V) depends on the oxygen concentration in the supplied germanium hydride and the operating conditions, etc., and cannot be specified unconditionally.
Usually 100 cm / sec or less, preferably 30 cm / sec
sec or less. The contact temperature of the germanium hydride and the germanium compound of nickel or copper is the temperature of the gas supplied to the inlet of the refining column, and is about 200 ° C. or less, preferably 100 ° C. or less. do not need. There is no particular restriction on the pressure, normal pressure, reduced pressure,
The treatment can be carried out by any of pressure, but usually 20kg
/ Cm 2 abs or less, preferably 0.1 to 10 kg / c
m2abs.

In addition, even if a small amount of water is contained in the hydrogenated germanium, the deoxidizing ability is not adversely affected, and when a carrier is used, the water is also removed depending on the type. Is done. In the present invention, it is also possible to appropriately combine the water removal step with a dehumidifier such as a synthetic zeolite, if necessary, to the oxygen removal step with germanium nitride of nickel or copper,
As a result, water is completely removed, and purified germanium hydride with extremely high purity can be obtained.

[0013]

【Example】

Example 1 (Nickel reduction treatment) A commercially available nickel catalyst (N-111, manufactured by JGC Corporation) was used. Its composition is N
In the form of i + NiO, 45 to 47 wt% as Ni,
Cr 2-3 wt%, Cu 2-3 wt%, diatomaceous earth 27-2
9 wt% and graphite 4-5 wt%, specific surface area 150 m
² / g, a molded body having a diameter of 5 mm and a height of 4.5 mm. 63 ml of this nickel catalyst crushed to 8 to 10 mesh was packed in a stainless steel purification cylinder having an inner diameter of 16.4 mm and a length of 400 mm, and a filling length of 300 mm (filling density:
1.0 g / ml). Hydrogen was added thereto under normal pressure at a temperature of 150 ° C. and a flow rate of 456 ml / min (LV = 3.6 cm).
/ Sec) for 3 hours, and then cooled to room temperature. (Germanium compound of nickel) 2vol
% Of germanium hydride at 380 cc /
min (LV = 3 cm / sec) to convert nickel into germanium. The room temperature at this time was 25 ° C., but the temperature of the gas at the outlet of the cylinder rose to about 50 ° C. due to the heat generated by the conversion to germanium. Thereafter, the temperature of the outlet gas gradually decreased, and after 5 hours, returned to room temperature, thereby terminating the germanium treatment. In this state, nitrogen purge was further performed for 3 hours to prepare for germanium hydride purification. (Purification of germanium hydride) Subsequently, purification of germanium hydride was performed. 1 vol% of germanium hydride and 0.50 ppm as impurities
Of oxygen-containing hydrogen-based crude germanium hydride at a rate of 1266 cc / min (LV = 10 cm / min) at room temperature (20 ° C.) to cause a yellow phosphorus emission type oxygen analyzer (measurement lower limit concentration: 0.01 ppm). As a result, no oxygen was detected and the content was 0.01 ppm or less. After 100 minutes from the start of the purification, the oxygen concentration of the outlet gas was 0.01 ppm or less even when the gas flow rate was quadrupled.

Example 2 Commercially available copper oxide catalyst (G10 manufactured by Nissan Gardler Co., Ltd.)
8) was used. It uses SiO ₂ as a carrier, has a Cu content of 30%, a diameter of 5 mm and a height of 4.5.
mm. This copper oxide catalyst is 8-10mes
h, crushed to 63 ml, inner diameter 19 ml, length 400
A stainless steel purification cylinder having a packing length of 300 mm (a packing density of 1.0 g / ml) was packed. (Germanium compound of copper) Nitrogen containing 2 vol% of germanium hydride was supplied to this purification cylinder at 380 cc / min.
(LV = 3 cm / sec) to make nickel into germanium. At this time, the room temperature was 25 ° C., but the temperature of the gas at the outlet of the cylinder rose to about 55 ° C. due to the heat generated by the formation of germanium. Thereafter, the temperature of the outlet gas gradually decreased, and after 7 hours, returned to room temperature, and the germanium treatment was completed. In this state, nitrogen purge was further performed for 3 hours to prepare for germanium hydride purification. (Purification of germanium hydride) Subsequently, purification of germanium hydride was performed. In this purifier, a crude hydrogen-based germanium hydride containing 1 vol% of germanium hydride and 0.50% of oxygen as an impurity was added.
When measured at room temperature (20 ° C.) at a flow rate of 66 cc / min (LV = 10 cm / min) using a yellow phosphorus luminescence type oxygen analyzer (measurement lower limit concentration: 0.01 ppm), no oxygen was detected. It was less than 01 ppm. After 100 minutes from the start of the purification, the oxygen concentration of the outlet gas was 0.01 ppm or less even when the gas flow rate was quadrupled.

Comparative Example 1 35 g of activated carbon (coconut shell charcoal) crushed to 8 to 24 mesh was placed in the same purifying cylinder as in Example 1 at 300 mm.
(Filling density: 0.57 g / ml), the mixture was heated in a helium gas stream at 270 to 290 ° C. for 4 hours, and then cooled to room temperature. 1 vol% of the same germanium hydride used in Example 1 and 0.50 ppm as impurities
Of hydrogen-containing crude germanium hydride containing oxygen at a flow rate of 1266 cc / min (LV = 10 cm / min) at room temperature and measured using a yellow phosphorus emission type oxygen analyzer (measurement lower limit concentration: 0.01 ppm). , 0.50p
pm, and the flow was continued for 2 hours in this state, but no change in oxygen concentration was observed.

[0016] Example 3 Al (NO ₃₎ in water (nickel Preparation of Catalyst) 3L ₃ 9
454 g of H ₂ O were dissolved and cooled to 5-10 ° C. in an ice bath. While stirring vigorously, add 200g of NaOH to this
Was dissolved in 1 L of water and a solution cooled to 5 to 10 ° C. was added dropwise over 2 hours to obtain sodium aluminate. next,
Ni (NO ₃ ) ₂ .6H ₂ O, 101 g, was dissolved in 600 ml of water, and 45 ml of concentrated nitric acid was added thereto.
The solution cooled to ° C. was added to the sodium aluminate solution over 1 hour with vigorous stirring. The resulting precipitate was filtered, and the obtained precipitate was stirred six times in 2 L of water for 15 minutes and washed to make the precipitate neutral. The obtained precipitate was subdivided, dried in an air bath at 105 ° C. for 16 hours, and then pulverized, and sieved to collect 12 to 24 mesh. It contained 29.5 wt% nickel oxide (NiO). (Reduction treatment of nickel) 63 ml of this was packed in the same purification cylinder as used in Example 1 (packing density: 0.77 g)
/ Ml) and hydrogen at normal pressure at a temperature of 350 ° C and a flow rate of
After reducing at a flow rate of 3 cc / min (LV = 1 cm / sec) for 16 hours, nickel was converted to germanium under the same conditions as in Example 1. (Purification of germanium hydride) Subsequently, purification of germanium hydride was performed. 1266 cc / m2 of the same crude germanium hydride used in Example 1 was added to this purification cylinder.
in (LV = 10 cm / min) at room temperature (20
° C) and a yellow phosphorus emission type oxygen analyzer (measurement lower limit concentration: 0.
As a result, no oxygen was detected and the content was 0.01 ppm or less. In this state, the flow was continued for 10 hours, but the oxygen concentration of the outlet gas was 0.01 ppm or less.

Example 4 (Adjustment of Copper Oxide Catalyst) 20 wt% of sodium carbonate was added to a 20 wt% aqueous solution of copper sulfate until the pH became 9 to 10, to precipitate crystals of basic copper carbonate. The crystals are repeatedly filtered, washed, dried at 130 ° C. in an air stream, and then dried.
Calcination at 0 ° C. produced copper oxide. This copper oxide was treated with alumina sol (Cataloid-A, manufactured by Kasei Kagaku Kogyo KK).
S-2) was mixed and kneaded with a kneader. Subsequently, it was dried at 130 ° C. in the air, and further calcined at 350 ° C., and the calcined product was crushed into granules. This was formed into a cylindrical pellet having a diameter of 6 mm and a height of 4 mm by tableting. This was crushed and shaken to collect 12-24 mesh. (Germanium compound of copper) 63 ml (100 g, packing density of 1.6) was placed in the same purification cylinder as used in Example 1.
g / ml) and filled with 380 cc / min of nitrogen containing 10 vol% of germanium hydride (LV = 3
(cm / sec) for 3 hours to convert copper into germanium. (Purification of germanium hydride) The same crude germanium hydride used in Example 1 was added to this purification cylinder at 1266 cc / m2.
in (LV = 10 cm / min) at room temperature (20
° C) and the oxygen concentration was measured. As a result, no oxygen was detected and the concentration was 0.01 ppm or less. In this state, the flow was continued for 10 hours, but the oxygen concentration of the outlet gas was 0.01 ppm or less.

[0018]

According to the present invention, it is possible to remove oxygen in germanium hydride, which was difficult to remove conventionally, to an extremely low concentration of 0.1 ppm or less, and even 0.01 ppm or less. As a result, it has become possible to obtain ultra-high-purity purified germanium hydride that has been demanded.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-170405 (JP, A) JP-A-60-16802 (JP, A) JP-A-2-204304 (JP, A) (58) Field (Int. Cl. ⁷ , DB name) C01G 17/00 C01B 6/34

Claims (3)

(57) [Claims] 1. A method for purifying germanium hydride, comprising contacting crude germanium hydride with germanium nickel or copper to remove oxygen contained in the crude germanium hydride. 2. The germanide of nickel or copper,
The method for purifying germanium hydride according to claim 1, which is obtained by bringing nickel or copper into contact with germanium hydride. 3. The method for purifying germanium hydride according to claim 1, wherein the contact temperature between the crude germanium hydride and germanium nickel or copper is 200 ° C. or less.