Semiconductor structures having a gate field plate and methods for forming such structure

摘要

A field effect transistor structure having a semiconductor having a source region, a drain region, and a gate contact region disposed between the source region and the drain region; and a gate electrode having a stem section extending from a top section of the gate electrode to, and in Schottky contact with, the gate contact region. The stem section has an upper portion terminating at the top portion of the gate electrode and a bottom portion narrower than the upper portion, the bottom portion terminating at the gate contact region. The bottom portion of the stem has a step between the upper portion of the stem section and the bottom portion of the stem section in only one side of the stem section. The step of the stem section provides an asymmetric field plate for the field effect transistor.

主权项

1. A field effect transistor structure, comprising:
a semiconductor having a source region, a drain region, and a gate contact region disposed between the source region and the drain region; a gate electrode having a stem section extending from a top section of the gate electrode to, and in Schottky contact with, the gate contract region; wherein the stem section has an upper portion terminating at the top portion of the gate and a bottom portion narrower than the upper portion, the bottom portion terminating at the gate contact region; wherein the bottom portion the stem has a step between the upper portion of the stem section and the bottom portion of the stem section in only one side of the stem section including a pair of dielectric spacers disposed on sides of the stem section, the pair of dielectric spacers having different etch rates to a predetermined etchant, one of the pair of dielectric spacers being shorter than the other one of the dielectric spacers.