Patent ID: 8368127

Claim:
A method of forming a tunneling field effect (TFET) semiconductor device, the method comprising: providing a substrate comprising a first substrate material; providing a gate structure on the substrate, the gate structure comprising a gate and a gate dielectric; forming a drain region of a first conductivity type adjacent the gate structure; forming a source region adjacent the gate structure, wherein at least a portion of the source region is positioned underneath the gate dielectric such that the gate dielectric overlaps the source region, and wherein forming the source region further comprises, forming a first source region having a layer of undoped silicon germanium (SiGe), and forming above the first source region a second source region having a layer of doped SiGe of a second conductivity type; and wherein forming the source region further comprises: forming amorphous germanium on a surface of the doped SiGe layer, and annealing the amorphous germanium to drive germanium into the doped SiGe layer thereby increasing germanium content of the doped SiGe layer.