Out-of-town plenary meeting of the Scientific Council of the USSR Academy of Sciences on the Problem of Coherent and Nonlinear Optics, Kishinev, December 3–5, 1984

Abstract

Erosion and changes in the sidewall smoothness d masking layers commonty used as dry etch masks for iil-V semiconductors have been studied for U?-, F2-and CHa/HZ-based discharges. A panicular problem with photoresist masks is the introduction of sidewall roughness which i s transferred into the underlying dielectric or semiconductor. Distortion of the resist mask also occurs during high DC bias dry etching, leading to feature widths wider than the original mask dimension. Both d these phenomena are minimized with the use d low (-100 V DC) seif-bias during the etching. Dielectric layers such as SiOl display erosion and faceting d the mask edges during extended high-bias dry etching and for small (< 1 pm) feature widths this can lead to trenching at the base of the sidewalls. Metal-based (AI, TilAu) masks are much more resistant to erosion and appear to be favoured when etching deep (> 2 pm) features into both GaAs and InP Anenide and Relared Compounds 1985 (Inst. Phys. Cant Sec 79) ed M Fujimoto (Bristol: Institute of Physics) p 367 Vodjani N and Parrens P 1987 1. V a c Sci Technol. B 5 Katz A, Pearton S J and Geva M 1990 J. AppL PiIys. 68 3110 Katz A, Pearton S J and Geva M 1991 AppL P / y s Lett. 59 286