Reactive ion-etching-induced damage in silicon using SF6 gas mixtures

Abstract

Damage introduced in silicon during reactive‐ion etching (RIE) in SI6 gas containing 10 Vol % of H2, He, N2, O2, or Ar has been investigated using Schottky barrier measurements and Rutherford backscattering. RIE was performed at 0.1 Watt cm−2 power density with the radio frequancy (rf) cathode covered with a quartz plate. The annealing effect on damage was studied at various temperatures up to 800 °C in dry N2. The results indicate that the damage has two components namely, a shallow near‐surface region with lattice damage and a deep layer containing discrete defect centers which act as donors. The extent of the deep damage layer is the net balance between two competing processes: (a) the etch rate, and (b) the rate of damage migration into silicon. However, the damage has been found to reach a saturation level after RIE for 1 min in all the gas mixtures studied. The results also suggest that RIE in SF6+10% H2 gas mixture causes a deep damage layer which could, however, be annealed at 150 °C aided signifi...