Low band gap semiconductor devices having reduced gate induced drain leakage (gidl) and their methods of fabrication

A method of forming a device comprising:

• forming a first semiconductor material above a substrate, the first semiconductor material having a first band gap;
• forming a gate dielectric on a surface of the first semiconductor material;
• forming a gate electrode on the gate dielectric layer;
• forming a second semiconductor material having a second band gap on the first semiconductor material on opposite sides of the gate electrode, the second band gap greater than the first bandgap;
• and
• forming a third semiconductor material having a third band gap on the second semiconductor material on opposite sides of the gate electrode.

A device comprising:

• a fin comprising a first semiconductor material having a first band gap, the fin having a top and laterally opposite sidewalls;
• a gate dielectric layer on the top and laterally opposite sidewalls of the fin;
• a gate electrode on the gate dielectric layer on the top and laterally opposite sidewalls of the fin;
• a pair of source/drain region on opposite sides of the gate electrode, the pair of source/drain regions comprising a second semiconductor material having a second band gap, and a third semiconductor material having a third band gap, wherein the second semiconductor material is between the first semiconductor material and the third semiconductor material, and wherein the second band gap is greater than the first band gap.