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

Abstract

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