Selective Chemically Assisted Ion Beam Etching of Si, Polysilicon, and SiO2 Using Ni‐Cr Masks and Cl2

Abstract

The etching of single‐crystal silicon, CVD polysilicon, thermally grown silicon oxides, and Ni‐Cr masks have been studied using a chemical‐assisted ion beam etching (CAIBE) process. Etch rates were measured as functions of gas flow rate, Ar+ ion beam energy, and beam current density. Selectivities of Ni‐Cr:Si, Ni‐Cr:poly, and of 1:10, 1:9, and 1:4 were determined. Vertical profiles were obtained down to at least 100 nm linewidths using CAIBE.