JPS6278116A - Purification of arsine - Google Patents

Abstract

PURPOSE:To obtain high-purity arsine, by contacting crude arsine with a substance capable of adsorbing arsine, thereby removing oxygen from crude arsine. CONSTITUTION:Crude arsine (AsH3) produced either by decomposing a metal arsenide or by reducing AsCl3 with LiAlH4 is made to contact with a substance capable of adsorbing arsine (e.g. molecular sieve carbon) under a pressure above atmospheric pressure at $030 deg.C- room temperature to effect the removal of oxygen from the crude arsine. If necessary, the treated arsine is further contacted with a substance capable of removing water (e.g. synthetic zeolite) to obtain purified arsine having an oxygen content of <=1ppm and a water- contact of <=1ppm and suitable as a raw material for semiconductor.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention purifies arsine containing impurities into high NU arsine used in semiconductor manufacturing etc. [Prior art] Arsine (arsenic hydride, Demand for A s Hs ) is rapidly increasing in the semiconductor industry as a group V raw material during epitaxial film formation of IV concentrated compound semiconductors or as a doping material during silicon semiconductor manufacturing.

The amount of A*Hs used during the semiconductor manufacturing process is 1 vol ppm (hereinafter referred to as ppm) or less per 1 vol of oxygen in AsH3 in order to improve the mechanical performance and productivity of the semiconductor.

H,01ppm (dew point knee 76°C) or less.

There are many methods for producing A s)l s, but one representative example is: (1) Method of decomposing metal arsenide with dilute hydrochloric acid Room temperature Zn1Ast + 6HCJ - + 2AsHs + 3Zn
Cj! *(2) Method of reducing arsenic trichloride with LIAJ) (, -90℃ 4 A s Cl s + 3L I Al!H4→4
Al) (S+ 3L IAJc74, etc.).

AlH34 synthesized by these methods, deoxygenation with pyrogallol, etc., deoxidation with NaOH water fI solution.
After dehydration with ot, p, o, etc.

Human SH1 with less impurities is obtained. However, this A
@Hs contains some metal of Zn$ introduced from the raw material and 0. ≦20ppm% ≦tooppm, co, ≦10
ppm, CO≦sppm, CH,≦5ppm, kltO
≦aoppm, etc. are included. Human IH3 (hereinafter referred to as crude A s Hs) contains this level of impurities.

It is unsuitable as a raw material for the semiconductor industry, especially I(,0 and 0
, must be removed to below tppm, respectively, as described above. At this time, H,0 can be easily reduced to i ppm or less by adsorption and removal with synthetic zeolite such as M84A and MS5A manufactured by Union Showa Co., Ltd.; No method has been announced to reduce the amount of energy to lppm or less.

[Problem that the invention seeks to solve]

In view of the above circumstances, the present inventors conducted intensive research to remove 0 in Kumite sH3, and as a result, the rough A a Hs t? A
It has been found that when brought into contact with a substance that has adsorption capacity for s Hs, the concentration of O2 contained therein is significantly reduced.

The present invention was developed based on the above knowledge, and it is possible to reduce the Otd degree in crude A s Hs to 1 ppm or less, and to remove H and 0 together.
An object of the present invention is to provide a method for purifying s Hs.

[Problem that the invention seeks to solve]

The present invention has been made to achieve the above object, and its gist is that crude arsine is brought into contact with a substance that has adsorption ability for A@H3. A s to remove
Ha! R manufacturing method and cosmetic arsine, A s Ha
A method for purifying arsine includes contacting the arsine with a substance having an ability to absorb 21F, and then contacting the substance with a substance capable of removing water to remove oxygen and water.

[Specific structure and operation of the invention]

The substances used in the present invention that have adsorption fd for A m Hs (hereinafter referred to as A=Hs adsorbent) include (a)
Activated carbon 1 For example, coal-based activated carbon, petroleum-based activated carbon, molecular sieve carbon (M2O), etc. (cut) Synthetic zeolite, such as Molekira Sieves manufactured by Union Showa Co., Ltd. (M813X%MS10X%M85A)
etc.) O9 ion exchange synthetic zeolites, such as Zn (MS4A4, etc.) activated alumina, etc.

By contacting crude A s Hs with A a H, an adsorbent, 0! The mechanism by which AsH is removed is unclear, but AsH
When O3 diluted with He was passed through the molecular sieve carbon 3A layer, which is an adsorbent, breakthrough occurred in 125 minutes, whereas AS
After diluting H with He, O! The gravity is a, and the above 0. When passed through the A s Hs adsorbent layer at the same concentration and at the same speed, there was no breakthrough of 0 snow for more than 19 hours, so the removal of 0 snow was not just physical adsorption, but the A a Hs 1 person $H1 and 0 due to the catalytic action of the adsorbent
．． It is presumed that this is a reaction.

The above reaction is.

4AsH3+ 3ot→4 A s + 6 Hz O
Or 2AsHs + 30tA@tOs
+ 3Ht O, A s Ha with strong affinity is adsorbed on the surface of the A a Hs adsorbent, and this reacts with O2 to form As.
or generate A s t Os and Hlo and 0. I think that will disappear.

In that case, the boiling point of As, A m @ 03 is As:6
15℃A110! : At 415℃, while A s Hs
Since the temperature is -54.8℃, the difference in vapor pressure is extremely large, and the A s Ha that has passed through the A m Hs adsorbent contains A
s, A I *Os are not included. In addition, since HIO has a steam BE of about 15 to 30 Hg at room temperature, H2O produced by the reaction flows out together with H,0 in the crude A s Ha, but this is removed by a well-known dehydrating agent.
You can search.

Above, 0. The conditions for the removal reaction are not strict, and the purification A s
0.0 in Ha. Although it is relatively easy to reduce the concentration to 1 ppm or less, in order to efficiently remove Os, it is desirable to bring the AsHs adsorbent into contact with the crude As Ha under primary conditions. That is, (1) reaction temperature knee 30
℃ or more.

The reaction temperature can be easily set at a temperature at which As Hs does not liquefy, taking into consideration the pressure, and is usually preferably in the range of -30°C to room temperature. However, the higher the reaction temperature, the more AsH
Perhaps because the reaction rate constant between 3 and Ol becomes larger, 0. The removal rate becomes high, and it becomes possible to take a large Sv.

(11) Reaction pressure crab atmospheric pressure or higher.

If the reaction pressure is lower than atmospheric pressure, air will enter the reaction system, causing contamination within the system. Therefore, it is preferable to keep the pressure inside the system at or above atmospheric pressure. However, the higher the pressure, the more A a
The partial pressure of Hs increases, the adsorption amount of A a Hs increases, and 0. Perhaps because the reaction rate with 0. becomes easier to remove.

The adsorption amount of A s Hs to the OjD A s Hs adsorbent is -30°C% 1.5 kg/crtl G.

1 = 9 kmHs / 10011 AsHs absorption agent or more Tealco is preferable. A to A s Hs adsorbent
If sHs absorption yIIIt is small, O2 in the crude A a He cannot be removed sufficiently. For example, 0 at -30℃! In order to remove the
A a H>The amount of adsorption on the adsorbent is at least 1
,! 9 A a Hs /1009 A Hs adsorbent is preferred.

However, the above conditions are not absolute, and the crude A m H3
It is also adjusted by the feeding speed of 0! concentration lr)
I) It is possible to make it less than or equal to m.

The above removal of Ol is performed using crude A s Hs 1tA s H
When passed through a 3-absorbent adsorbent, A s Hs is initially adsorbed and does not flow out, but after being saturated and adsorbed, 0. A s Hs from which has been removed flows out.

After 0□ is removed, H,0 is removed by a common dehydrating agent, and A s Hs becomes 0! , H2C are both lppm
The following A a Hs is obtained.

As a dehydrating agent, HtO'e in AsHs 11) pm
Any of the following can be used as long as it is removed.

For example, 1 synthetic zeolite (M813X1MSIOX, M85A, MB2,
MS3A, etc.), natural zeolite (mordenite type, phaujasite type), silica gel, activated alumina, activated clay, acid clay, etc. 1. Any of the usual ones can be used.

Some of the above-mentioned physical adsorption dehydrating agents have an ability to adsorb A s Hs. When such an adsorbent is used, 0. is removed, H,0 is also adsorbed and removed, and 0! is removed by one type of adsorbent layer. , H, and 0 are removed, A s Hs is obtained.

[Example, comparative example]

Next, the present invention will be explained by showing examples and comparative examples.

In Examples and Comparative Examples, some of the crude A*H
3 was used, but AsH3 is extremely toxic.

In order to facilitate its handling, most of the tests were carried out by diluting As Hs to 2 to 5 vol% (hereinafter simply referred to as Chi) with He, and diluting As Hs to a concentration that is approximately the same as that of crude As Hs. A model gas to which Ot J (t O, etc.) was added was prepared and used as the raw material gas for the test.

The reason is that crude A s Hs has a high A s Hs d degree, and A s Hs absorbs more S* to ASH and adsorbent than the model gas. Therefore, 0. The reaction between A and Hl is promoted, and 0. The removal efficiency is better than that of the model gas. Therefore, if Ol can be removed by the model gas, applying this to A s Hs, 0
．． It is assumed that the particles are removed efficiently.
Koyoru.

3. The analysis used was A a Hz: J I SK
O102 (diethyldithiocarbamine & 8 method), 02.
Nl: Helium ionization detector method is chromatography (hereinafter referred to as HI D-G C (!: Iu), H, U:
Measurement at point g (using a capacitive dew point meter) was carried out.

[Example 1] An 8 to 24 Messinian crushed product of molecular sieve carbon 3A (1molsibon HGS-062, manufactured by Takeda Pharmaceutical Co., Ltd.) near 0.
8.9 as an A a Hs adsorbent was filled into an adsorption tube with an inner diameter of 31 mm and a length of 20 cIrL, and after heating and activation in a helium stream at 270 to 290 °C for 4 hours, the adsorption tube was heated to 2 kL.
After pressurizing the fi/crtt G, both ends were sealed and cooled to room temperature.

Ol' into the adsorption tube filled with this molecular sieve carbon 3A
29pPrn-N2: 107pprn, As
A raw material gas consisting of Hs: 2.65% Ha: 97.34% was heated at 21°C, 9/altG to 0.3, and gas flow rate:
It was introduced at a rate of 0.4 Nl/m and flowed out from the tube ffl 11 side. A s Hs broke through 40 minutes after the start of feeding. After that, raw materials were continued to be fed for 19 hours, but zero
．． The concentration was less than lppm.

In this case, A sHs adsorbed on three single-molecular sieve carbon
The amount of was 3.59 people sHs/100 Ji' molecular sieve carbon.

[Comparative Example 1] Ot: 29p containing no A s Hs by casting the raw material
The test was conducted under the same conditions and operations as in Example 1, except that pmNt' 1107pp%He:99.99% was used. As a result, after starting feed gas supply, Nt
The breakthrough occurred after 4 minutes and O3 after 125 minutes.

From the results of Example 1 and Comparative Example 1, 0. It can be seen that the removal of is not simply physical adsorption.

[Example 2] Activated carbon (manufactured by Kureha Chemical Co., Ltd., Peace Charcoal MP) 20~
60 mesh spherical product: Fill an adsorption tube with an inner diameter of 74.4 mm and a length of C60 (1111) with 7sg of 'i, 7sg as an A*Hs adsorbent, and heat at 220-240℃ in a helium stream.
After heating and activation for 4 hours, the inside of the adsorption tube was pressurized to 2 to 9/·cdG, and both ends were sealed and cooled to room temperature. In this adsorption tube, Ol
: 47 ppm%N, : 206 ppm, AmHl
A raw material gas consisting of: 1.76%, He: 98.21% was fed at 23°C, 0.3 kg/cdL G, gas flow rate = 0.12 Nl/sIl, and was discharged from the adsorption tube outlet side. . After the start of sending.

AaHa broke through in 64 minutes. After that, the supply continued for 5 hours, but 0! The concentration was 11) pm or less. In this case, the amount of AsHs adsorbed on activated carbon is 9
．． 31 AsH3/100 & activated carbon.

[Example 3] 16 to 24 mesh pieces obtained by crushing 1/16 inch pellets of synthetic zeolite SA (Union Showa Co., Ltd., 5 members of Molecular Sieves) = 5.69 A * H
As an adsorbent, it was filled into an adsorption tube with an inner diameter of 4.4 mm and a length of 2601 mm, heated and activated in a helium stream at 320 to 330°C for 4 hours, and after pressurizing the inside of the adsorption tube to 2#/cdG, both ends were It was sealed and cooled to room temperature.

Into the adsorption tube filled with this synthetic zeolite) 5A, O
@'21 ppm-Nt'98 ppm%H@
0: Crude ksHs f containing 391 points -60℃
, 23"0.0.3 to 9/a/l G, gas flow rate: 0.
It was fed at a rate of 12 Nl/- and flowed out from the outlet of the adsorption tube. After starting to feed crude Asf(s).

Human aL was broken in 5 minutes. Thereafter, the supply was continued for 9 hours, but the 01 concentration in the outflowing A m Ha was less than t ppm, and the dew point was -79°C. In this case, the amount of human aH1 adsorbed on five synthetic zeolites is 229-AsH3
/ 100 & was a synthetic zeolite.

[Example 4] 16-24 mesh crushed product of molecular sieve carbon 5A (Molecibon HGY-318, manufactured by Takeda Pharmaceutical Co., Ltd.) 4.2
The test was conducted under the same conditions and operations as in Example 2, except that Ashs 4.9 was used as the Ashs adsorbent.

AaH broke through 71 minutes after starting feed of the raw material gas.

After that, the supply continued for 3 hours, during which time the O in the outflow gas
The t concentration was below IJ)j)m. In this case, the amount of AaHs adsorbed on the molecular sieve carbon 5 is 11.
51' AsHs/100 g molecular sieve carbon.

[Comparative Example 2] A test was conducted under the same conditions and operations as in Example 2, except that a crushed 5.4511 kAaHs adsorbent obtained by crushing silica gel (manufactured by Mizusawa Chemical Co., Ltd., Neobead N.) beads was used. Ashes broke through 1 minute after starting feed of the raw material gas. After that, the outflow gas was immediately analyzed by HID-GC, and it was found that 0. : 32ppm, N@ : 201
TH)m'. After that, feed of raw material gas was continued for 60 minutes, during which gas analysis was conducted at appropriate times, but 0. :
32-341) 9ff1. N: 201-20
There was no change at 6pPm. In this case, the amount of AsHs adsorbed on the silica gel was less than 063 g/10 silica gel.

[Example 5] Molecular sieves 4A (Zn
Replacement M84A) Yo') Null 16-24 mesh crushed product 19 Jii' f As AiHs adsorbent, inner diameter =
After filling an adsorption tube with a length of 8 cm and a length of 53 cm, and heating and activating it in a helium air stream at 320 to 330 mm at 0% for 4 hours, the adsorption tube was pressurized to 2 kl/cdt G, then both ends were sealed and cooled to room temperature. Furthermore, the upper age sucking tube was cooled down to -30°C with water mK of CaC1,: 30wt@.
, AsH3: 3.2 yen, He: 96.78% raw material gas 1.51c9/C11tG, gas flow rate: 0
．． 0.05 Nll- was introduced and allowed to flow out from the outlet side of the adsorption tube. λs HB broke through 80 minutes after the start of feeding. After that, it was injected for 2 hours, but the O1 degree in the outflow gas was xppm.
It was below. In this case, the basin of A s Hs adsorbed on Zn-exchanged MS4A is 2.09 ksHs/10
0 F,” was the exchange MS4A.

[Comparative Example 3] Molecular sieves with a Zn exchange rate of 4.5% (Zn exchange M
S4A) 16-24 mesh crushed product: 19.8
Example 5 except that g was used as the A@Hs adsorbent.
Seven were tested under the same conditions and operations.

A s Hs broke through 41 minutes after the start of feeding. After that, feed of the raw material gas was continued, and 0.0% in the outflow gas after 50 minutes, 90 minutes, and 110 minutes. The concentration was measured.

0, the concentrations are 6 pI)m and 15 ppm, respectively.
, 19 ppm. In this case, the amount of A s Hs adsorbed on Zn-exchanged MS4A is 111 ・AsH
s/100 Ji, Zn exchanged MS4A.

[Example 6] Inner diameter: 4.4i+m, length = 60 ports, 2 adsorption tubes %B
Prepare a 20-60 mesh spherical product of activated carbon (Peace Charcoal MP manufactured by Kureha Chemical Co., Ltd.) in adsorption tube A: 4.8.9'
ii filled and adsorption tube B was filled with 4 synthetic zeolites (Union Showa gM S 4 A) '/16 Inf Here l'f: Crushed product crushed into 16-24 mesh = 5.
65.9 Fill the adsorption tube A% B? : Piped in series.

Inhale in a helium airflow! After heat activation for 4 hours at 220-250℃ for fA and 320-330℃ for B,
After pressurizing to 9/crltG, both ends were sealed and cooled to room temperature.

In the order of the adsorption tubes A to B, O: 19 ppm.

N: 1105pp, HlO: 8 points -60°C crude As
Hs at 24℃, 0.45/cg/c! /lG, gas flow rate: 0.12Nll/m. At the outlet of the adsorption VB, A@Hs broke through 6 minutes after the start of feeding. After that, the supply continued for 6 hours, but the O in the A a Hs that flowed out
1 concentration was below II)I)m, and the dew point was -82°C.

〔Effect of the invention〕

As described above, the A s Hs n-back method according to the present invention is difficult to remove even though it must be less than 11)I)m for semiconductor raw materials.
can be easily and efficiently removed from crude A s Hs, with a roughness of 0! Since HlO, which must be removed as a semiconductor raw material, can also be removed at the same time, it is a sophisticated method that can easily obtain A s Hs suitable for semiconductor raw materials.

Claims (3)

[Claims] (1) A method for purifying arsine, which comprises bringing crude arsine into contact with a substance that has adsorption ability for arsine to remove oxygen. (2) A method for purifying arsine, which comprises contacting crude arsine with a substance capable of adsorbing arsine and then contacting it with a substance capable of removing moisture to remove oxygen and moisture. (3) The method for purifying arsine according to claim 2, wherein the substance that has the ability to adsorb arsine is a substance that also has the ability to adsorb and remove moisture.