Composite Passivation Process for Nitride FET

摘要

A nitride-based FET device that provides reduced electron trapping and gate current leakage. The device includes a relatively thick passivation layer to reduce traps caused by device processing and a thin passivation layer below the gate terminal to reduce gate current leakage. The device includes semiconductor device layers deposited on a substrate. A plurality of passivation layers are deposited on the semiconductor device layers, where at least two of the layers are made of a different dielectric material to provide an etch stop. One or more of the passivation layers can be removed using the interfaces between the layers as an etch stop so that the distance between the gate terminal and the semiconductor device layers can be tightly controlled, where the distance can be made very thin to increase device performance and reduce gate current leakage.