Annealing of Si damage caused by reactive ion etching in SF6 gas mixtures

Abstract

Damage introduced in silicon during reactive ion etching (RIE) in SF6 gas mixtures has been studied using x-ray photoelectron spectroscopy, Schottky barrier measurements, and Rutherford backscattering. RIE was done at 0.1 W cm−2 power density with the rf cathode covered with a quartz plate, and the annealing behavior of damage was studied at various temperatures up to 800 °C in N2 ambient. The results obtained indicate the following: (a) contamination by F, S, and metal ions is insignificant; (b) lighter atoms such as hydrogen cause higher electrical damage and lower lattice damage, both of which can be annealed at 400 °C; (c) heavier atoms such as argon cause lower electrical damage but higher lattice damage which requires a temperature ≥800 °C for recovery.