THE REMOVAL OF HARD MASKS IN SEMICONDUCTOR PROCESSING

Semiconductor fabrication relies on masking layers to protect underlyi ng structures in many operations. The familiar photolithographic soft masks are primarily composed of organic materials. Hard masks, like th e SiN layer used in local oxidation (LOCOS), are mainly inorganic and are able to withstand more severe process environments. Thus, they req uire unique removal techniques. This article discusses wet and dry har d mask stripping methods.