Silicon material cleaning method

Abstract

The invention discloses a silicon material cleaning method, belongs to the technical field of semiconductor silicon materials, and solves the problems that cleanness of a traditional silicon materialcleaning method is not high, the purity of a cleaned silicon material is not high, and the performance of a product using a silicon material as a raw material is seriously affected. The method mainlyincludes grinding, acid washing, alkali washing, cleaning, wet oxygen impurity removal, washing and drying and other operational processes. The invention has high cleanliness and high purity of the cleaned silicon material, and the high-purity silicon material greatly improves the performance of the product using the silicon material as a raw material. The silicon obtaining rate is high, the silicon material running away in the cleaning process can be recycled, the effects of low carbon, energy saving and environment protection are achieved, considerable economic and social benefits can be created for enterprises, and thus the silicon material cleaning method is of great significance in the technical field of semiconductor silicon material.

Description

technical field [0001] The invention belongs to the technical field of semiconductor silicon materials, and in particular relates to a method for cleaning silicon materials. Background technique [0002] The purpose of cleaning the silicon material is to make the surface of the silicon material clean and free from impurity pollution, so as to ensure the purity of the silicon material, ensure the quality of the silicon material, and prevent pollutants from affecting the quality of products that use silicon material as raw material. According to the causes of pollutants, they can be roughly divided into particulate impurities, organic impurities, metal pollutants and other impurities with large segregation coefficients. Common particulate impurities include silicon nitride powder, dust, and fine sand; organic impurities exist in various forms on silicon materials, such as human skin oil, anti-rust oil, lubricating oil, rosin, wax, etc.; metal pollutants It exists on the silic...

AI Technical Summary

Problems solved by technology

Common particulate impurities include silicon nitride powder, dust, and fine sand; organic impurities exist in various forms on silicon materials, such as human skin oil, anti-rust oil, lubricating oil, rosin, wax, etc.; metal pollutants It exists on the silicon material in three surface forms of van der Waals attraction, covalent bond and electron transfer, which has a great impact on the minority carrier lifetime of the silicon ingot and will reduce the minority carrier lifetime

The cleanliness of silicon materials directly affects the performance of products using silicon materials as raw materials, such as solar cells; traditional silicon materials are mainly cleaned by pickling, but the acidic process is only good for cleaning metal pollutants, and for sticky Organic matter such as oil stains and fingerprints attached to the surface of polysilicon materials cannot be removed, nor can impurities such as boron and phosphorus with large segregation coefficients be removed

It can be seen that the traditional polysilicon material cleaning method has a low degree of cleanliness. The low degree of cleanliness and the low purity of the cleaned silicon material have seriously affected the performance of products using silicon material as raw material.