Separation method of quartz and silicon material in single crystal silicon crucible backing material

Abstract

The invention relates to a separation method of quartz and a silicon material in a single crystal silicon crucible backing material and belongs to the technical field of semiconductor separation. The invention aims to provide a method with short time and low energy consumption for separating quartz and a silicon material in a single crystal silicon crucible backing material. The technical scheme adopted by the invention is as follows: 1) crushing the crucible backing material to be separated into particles of which the particle size is no more than 10mm; 2) using pure water at 50 DEG C to prepare 50L of 10wt% alkaline solution; 3) in a constant temperature water bath, pouring 10kg of the crushed crucible backing material into the 50L of alkaline solution prepared in the step 2, and stirring; 4) adding 10ml of foaming agent into the alkaline solution; 5) pumping air into the alkaline solution so as to ensure that the silicon material can float on the liquid level along with bubbles generated on the surface of the silicon material, collecting the floating silicon material; and 6) recycling the quartz at the bottom after collecting the floating silicon material. The separation methodis used for separating the quartz from the silicon material in the single crystal silicon crucible backing material.

Description

technical field [0001] The invention discloses a method for separating quartz from silicon material in the bottom material of a single crystal silicon crucible, belonging to the technical field of semiconductor separation, in particular to a process for separating quartz in the bottom material of a single crystal silicon crucible. Background technique [0002] In the production of single crystal silicon rods, some residual silicon materials will inevitably be produced, and these residual silicon materials on the bottom of the pot are called pot bottom materials. When pulling single crystal silicon, the silicon material will be melted on the bottom of the quartz crucible, so there will be white quartz crucible residues attached to the gray silicon material, and these silicon materials with quartz attached are all primary waste. Silicon material. In order to make full use of the silicon material, the quartz and silicon material in the bottom material of the pot must be separa...

AI Technical Summary

Problems solved by technology

This method not only takes a long time, but also consumes a lot of hydrofluoric acid, and the investment in environmental protection is large.

Another method is to realize separation by heating and cooling according to the different expansion coefficients of quartz and silicon materials, and to realize separation by remelting using the different melting points of quartz and silicon materials, but these two methods not only require a large amount of high-temperature heat energy , and it takes a long time. In addition, high temperature treatment is also likely to cause impurities to diffuse into the silicon material, reducing the quality of the recovered silicon material