DRY-ETCHING OF III V-SEMICONDUCTORS - FINE-TUNING OF PATTERN TRANSFERAND PROCESS-CONTROL/

Progress in dry etching processes [reactive ion etching (RIE) and elec tron cyclotron resonance etching, (ECRE)] is described, concerning etc h geometry and fidelity of pattern transfer by using advanced techniqu es to produce masks of photoresist and Al2O3 or SiO2. In contrast to c apacitively coupled hydrogen/methane discharges, in which the etch rat e of GaAs is significantly lower than that of InP, in ECR discharges b y the simple variation of the gas composition, the etch rate of GaAs c an be driven to values comparable with InP. The different on-line moni toring techniques are compared. It is shown that optical emission spec troscopy can be applied successfully even with sample areas of about 2 cm(2) at etch rates of 50 nm/min.