Formation of Mach angle profiles during wet etching of silica and silicon nitride materials

摘要: Abstract In integrated circuit technology peeling of masking photoresist films is a major drawback during the long-timed wet etching materials. It causes an undesired film underetching, which often accompanied by formation complex etch profiles. Here we report on detailed study wedge-shaped profile in series silicon oxide, oxynitride and nitride materials buffered hydrofluoric acid (BHF) solution. The shape etched profiles reflects time-dependent adhesion properties to particular material can be perfectly circular, purely linear or combination both, separated knee feature. Starting from formal analogy between sonic boom propagation underetching process, model wedge mechanism analytically. This predicts final form as function time fits experimental data perfectly. We discuss how this knowledge extended design realization optical components such highly efficient etch-less vertical tapers for passive photonics.