Mechanism and Principles of Post Etch Al Cleaning With Inorganic Acids

摘要

Dilute sulfuric acid solutions have become very popular for post Al etch cleaning. Post Al etch cleaning is still very important for most memory fabrication and for bond pad cleaning. Traditionally hydrogen peroxide has been added to sulfuric acid to increase the etch rate of aluminum and hence the cleaning. However, cleaning without hydrogen peroxide (sulfuric acid/HF only) is perfectly possible and in most cases adequate. The comparison with and without hydrogen peroxide is shown in fig. 7 (with hydrogen peroxide) and in fig. 8 (without hydrogen peroxide).