Heterojunction device

摘要

A metal-insulator-semiconductor field effect transistor using an undoped AlGaAs layer as an insulator over an n-type GaAs channel. The high breakdown field of the wide-bandgap AlGaAs results in a very high gate breakdown voltage and a low prebreakdown gate leakage current. The presence of the gate insulator also reduces the gate capacitance, Cgs. Moreover, the electron density in the channel is not all concentrated next to the heterojunction, which means that the series resistance of the channel is low, and also means that channel mobility will not be degraded by a less-than-perfect interface at the heterojunction.