Field effect transistor with elevated active regions and methods of manufacturing the same

Abstract

A field effect transistor having a higher breakdown voltage can be provided by forming a contiguous dielectric material layer over gate stacks, forming via cavities laterally spaced from the gate stacks, selectively depositing a single crystalline semiconductor material, and converting upper portions of the deposited single crystalline semiconductor material into elevated source/drain regions. Lower portions of the selectively deposited single crystalline semiconductor material in the via cavities can have a doping of a lesser concentration, thereby effectively increasing the distance between two steep junctions at edges of a source region and a drain region. Optionally, embedded active regions for additional devices can be formed prior to formation of the contiguous dielectric material layer. Raised active regions contacting a top surface of a substrate can be formed simultaneously with formation of the elevated active regions that are vertically spaced from the top surface.