Hydrogen Silsesquioxane (HSQ) Etching Resistance Dependence on Substrate During Dry Etching

Abstract

This work demonstrates hydrogen silsesquioxane (HSQ) etching resistance dependence on substrate. It is found that HSQ is barely etched on SiO2/Si substrate, while ≈15 and ≈70 nm HSQ is etched on Si and GaSb substrate by inductively coupled plasma (ICP) dry etching. The difference in the etching rate of HSQ can be ascribed to the conductivity variance of the substrates. The higher substrate conductivity, the higher self-bias is formed at the substrate surface, resulting in a stronger ion bombardment.