Extended-drain metal-oxide-semiconductor devices with a silicon-germanium layer beneath a portion of the gate

Abstract

Structures for an extended-drain metal-oxide-semiconductor device and methods of forming a structure for an extended-drain metal-oxide-semiconductor device. The structure includes a semiconductor substrate containing a first semiconductor material, a source region and a drain region in the semiconductor substrate, a gate electrode positioned in a lateral direction between the source region and the drain region, and a semiconductor layer positioned on the semiconductor substrate. The semiconductor layer contains a second semiconductor material that differs in composition from the first semiconductor material. The gate electrode includes a first section positioned in a vertical direction over the semiconductor layer and a second section positioned in the vertical direction over the semiconductor substrate.