Selective chemically assisted ion beam etching of Si, polysilicon, and SiO2 using Ni-Cr masks and Cl2

Journal article, 1990

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 Cl2 gas flow rate, Ar+ ion beam energy, and beam current density. Selectivities of Ni-Cr:Si, Ni-Cr:poly, and Ni-Cr:SiO2 of 1:10, 1:9, and 1:4 were determined. Vertical profiles were obtained down to at least 100 nm linewidths using CAIBE