Technique for purifying and recovering argon gas by rare earth lanthanide series radical alloy degasser in single-crystal silicon preparation

Abstract

The invention discloses a rare earth lanthanide base alloy getter (CF01 agent), comprising 65% of rare earth lanthanide and 35% metal element. Said rare earth lanthanide includes lanthanum, cerium, praseodymium and Neodymium; and said metal element concludes ferric, titanium, magnesium, copper and zinc. The invention also discloses a method for purifying argon gas with CF01 agent during high-purity argon gas preparation, which comprises following steps: (1) preparing high-purity argon gas through purifying cheap and non-high purity argon gas by using CF01 agent, and applying it into single-crystal silicon preparing process; (2) purifying and cyclic recovering argon gas from mono-crystal single-crystal silicon with CF01 agent; (3) purifying and cyclic recovering argon gas from czochralski single-crystal silicon with CF01 agent; (4) purifying and recovering (not cyclic) argon gas from mono-crystal and czochralski single-crystal silicon and preparing regenerative high-purity argon gas. The CF01 agent is characterized in that the comprehensive gettering performance and ratio of performance to price are better than that of current ones, and it can also recover argon gas discharged in single-crystal silicon preparation process, which can not only increase economic benefit, but also save energy and protect environment.

Description

technical field [0001] The invention relates to the purification and recovery of argon, more specifically, the preparation process of using a rare earth lanthanide-based alloy getter to purify argon and recover argon in the preparation of single crystal silicon. Background technique [0002] Argon is an inert gas and does not react chemically with any substance. Therefore, it is widely used in many industries of the national economy as protective gas, carrier gas, and dilution gas, such as electronics, metallurgy, chemical industry, physical and chemical analysis, light source, welding , Monocrystalline silicon preparation, etc. In the application, its inertness is mainly used, so the purity of argon is required to be as high as possible, and the impurities contained in it are as small as possible, so as not to lose the protective effect due to the reaction of impurities with the protected substance. Among them, single crystal silicon is the basic material of the electronic...

AI Technical Summary

Problems solved by technology

(Rare Metals, Volume 12, Issue 5, 1988. Zhang Yiyan, "Selection of Argon Purification and Recovery Schemes in Silicon Single Crystal Plants") But this technology still has the following shortcomings: 1. Mixed rare earths are difficult to process, and the relatively large surface area affects the purification efficiency

2 Mixed rare earths are very active and easily oxidized in the air, making it difficult to preserve

It is easy to catch fire when filling, so it is not safe

3 Sponge titanium is only used as a filler to increase porosity, and the gas absorption efficiency is not high at 400 ° C. If the temperature is too high, the rare earth will be sintered

4Mixed rare earth and sponge titanium are semi-finished products, and the high impurity content may affect the quality of monocrystalline silicon

5 Silicon single crystal argon recovery process uses the above-mentioned purifying agent, so in the whole recovery and purification process, a multi-stage process with the final check of mixed rare earth is adopted, and the process flow is very complicated

At that time, it was impossible to purchase a suitable small oil-free compressor, so the conventional oil-free compressor could only be sealed in the box. The cooling problem of the compression process was not completely solved, and the compressor was often damaged.

Frequent replacement of multiple presses has caused instability to the process

The labor intensity of workers is relatively high, and a little carelessness may cause a major accident, which directly affects the stability of the monocrystalline silicon process and product quality, causing great economic losses

Images