Highly selective etch process for the manufacture of GaAs power MESFET's

Abstract

In this paper, a highly selective etch process for the manufacture of GaAs power metal-semiconductor field-effect transistor (MESFET's) has been developed. The selective etch process using citric acid/potassium citrate/hydrogen peroxide solutions were studied. The experimental results were utilized to the gate recess process of the GaAs MESFET's for advanced wireless communication applications. When operating at a drain bias of 10 V and a frequency of 1.88 GHz, the 14.7-mm-wide MESFET's provided a maximum output power (Pout) of 38.8 dBm with a power-added efficiency (PAE) of 49.5% and a gain of 8.42 dB. The linear gain was 12.2 dB and the Pout at l-dB compression was 37.7 dBm with a PAE of 50.7%. The maximum PAE was 52.5%.