PROCESS AND APPARATUS FOR ETCHING OF THIN, DAMAGE SENSITIVE LAYERS USING HIGH FREQUENCY PULSED PLASMA

摘要

Disclosed is a system for etching thin damage sensitive layers with a plasma. The invention finds particular application for etching damage sensitive thin films such as Gallium Arsenide on Aluminum Gallium Arsenide. Damage to sensitive thin films is avoided by lowering the DC bias of the cathode (24). The low DC bias is achieved by increasing the frequency of the power source (26) producing the plasma. A reduced etch rate, suitable for etching thin layers, is achieved by pulsing the RF power source (26) between a high power and a low power at a selected duty cycle.