Scaling of Si and GaAs trench etch rates with aspect ratio, feature width, and substrate temperature

Abstract

The dependence of Si and GaAs trench rates on aspect ratio, french width and substrate temperature was investigated under constant Ar/Cl2 electron cyclotron resonance plasma conditions. Results showed that at higher substrate temperature, etching rates for both Si and GaAs scaled only with aspect ratio. At lower temperature (-45°C), etching rates scaled with both aspect ratio and trench width. The dependence of Si etch rate on feature dimension, however, was stronger than that of GaAs.