Improved drain current of diamond metal–semiconductor field-effect transistor by selectively grown p+ contact layer

Abstract

Diamond metal–semiconductor FETs are attractive for high-temperature, high-radiation proof electronics. However, in the lateral-channel structure, source/drain contacts directly deposited on the drift layer induce a high series resistance. To maximize the drain current, herein a heavily-boron-doped (p+) contact layer was introduced underneath the source/drain contacts by selective-area growth. The RT drain current density was effectively increased from 0.06 to 0.2 mA mm−1. Moreover, the contact resistance between the selectively grown p+ layer and the drift layer was evaluated by the transmission line model.