FinFETs with Strained Well Regions

摘要

A device includes a substrate and insulation regions over a portion of the substrate. A first semiconductor region is between the insulation regions and having a first conduction band. A second semiconductor region is over and adjoining the first semiconductor region, wherein the second semiconductor region includes an upper portion higher than top surfaces of the insulation regions to form a semiconductor fin. The semiconductor fin has a tensile strain and has a second conduction band lower than the first conduction band. A third semiconductor region is over and adjoining a top surface and sidewalls of the semiconductor fin, wherein the third semiconductor region has a third conduction band higher than the second conduction band.

主权项

1. A method comprising:
depositing a first semiconductor layer on a top surface and sidewalls of a semiconductor fin, wherein the semiconductor fin protrudes over top surfaces of isolation regions proximal the semiconductor fin, and the first semiconductor layer is undoped with n-type impurities during the depositing; depositing a second semiconductor layer over the first semiconductor layer, with the second semiconductor layer doped with an n-type impurity; depositing a third semiconductor layer over the second semiconductor layer; forming a gate dielectric over the third semiconductor layer; forming a gate electrode over the gate dielectric; and forming a source region and a drain region on opposite sides of the semiconductor fin.