Influence of reactive ion etching on the microwave trap noise generated inPt/n-GaAs Schottky diode interfaces

This work presents a systematic investigation of the influence of reactive ion etching (RIE) on the microwave noise performance of GaAs Schottky diode s. A number of devices has been fabricated by making use of RIE techniques in the anode window definition. The noise temperature measurements have rev ealed a strong degradation of the noise performance with RIE time, but no s ignificant changes have been observed on the barrier height. Different refi nements to the fabrication process that are typically utilized to reduce th e effects of RIE damage were tested. The use of thermal treatment at 400 de greesC after the RIE process was found to be the most effective procedure t o remove the sources of the measured excess noise, which are attributed to anomalies in the Ga coverage at the metal-semiconductor interface.