Cleaning method capable of improving quality of oxide layer

Abstract

The invention relates to a cleaning method capable of improving the quality of an oxide layer. The cleaning method is characterized by comprising the following steps that (1) a silicon wafer used before a growth process of the oxide layer is cleaned in DHF1 acid mixed liquor which is obtained by mixing HF and H2O of which the mass ratio is 1:20-30, and then the silicon wafer is washed cleanly with deionized water; (2) the silicon wafer is cleaned in APM acid mixed liquor which is obtained by mixing NH4OH, H2O2 and H2O of which the mass ratio is 1:2:12-15, and then the silicon wafer is washed cleanly with deionized water; (3) the silicon wafer is cleaned in SPM acid mixed liquor which is obtained by mixing H2SO4 and H2O2 of which the mass ratio is 3:1, and then the silicon wafer is washed cleanly with deionized water; (4) finally, the silicon wafer is cleaned in DHF2 acid mixed liquor which is obtained by mixing HF and H2O2 of which the mass ratio is 1:20-25, and then the silicon wafer is dried after being washed cleanly with deionized water. According to the cleaning method, conventional semiconductor equipment is adopted, and Cu and other precious metal impurities can be removed effectively.

Description

Technical field [0001] The invention relates to a cleaning method for silicon wafers before an oxide layer production process, in particular to a cleaning method that can improve the quality of the oxide layer. Background technique [0002] Looking at the development of semiconductor technology today, the critical dimensions of circuits are getting smaller and smaller, and the requirements for the quality of the oxide layer are getting higher and higher. As we all know, there are many factors that affect the quality of the oxide layer, but the impact of metal impurities has always been the key object of prevention and control in the process line oxidation process, because the contamination of metal impurities will cause a significant drop in oxide layer breakdown and an increase in leakage current. Traditional methods such as RCA, SC-1, SC-2 and other cleaning processes before oxidation growth can effectively remove the contamination effects of metal impurities. However, these c...

AI Technical Summary

Problems solved by technology

However, these cleaning processes are relatively weak in removing Cu and other precious metal impurities. At the same time, due to the development and diversification of the process, many small process lines use multiple process processing platforms at the same time, which can easily lead to Cu and other precious metal impurities. introduce

Although advanced cleaning equipment and technology can be used for treatment and anti-blocking, these methods must first invest in cleaning equipment (such as FSI), resulting in equipment capital investment, ultra-clean room equipment space occupation, equipment spare parts maintenance and Continuous consumption and other issues are unbearable for many small processing lines