III-V semiconductor device dry etching using ECR discharges

Abstract
Electron cyclotron resonance (ECR) discharges are characterized by high ion densities (12 cm-3) at low pressure ( approximately 1 mTorr) and by low ion energies (4/H2 plasmas and GaAs-based devices in CCl2F2 or PCl3 plasmas. The systematics of damage introduction into HEMTs and HBTs using these mixtures have been studied and the authors slow that it is possible to dry etch such devices without creating ion-induced surface damage. A feature of ECR etching is the highly anisotropic nature of the pattern transfer. The role of the masking material in the subsequent morphology of the sidewall is also discussed.