Source-channel junction for iii-v metal-oxide-semiconductor field effect transistors (mosfets)

A method for forming a semiconductor device, the method comprising:

• forming a channel area above a substrate, wherein the channel area includes a channel III-V material;
• forming a second portion of a source area above the substrate adjacent to the channel area, wherein the second portion of the source area includes a second III-V material;
• and
• forming a first portion of the source area above the substrate adjacent to the second portion of the source area, wherein the first portion of the source area includes a first III-V material;
• wherein the channel III-V material has a channel material bandgap and a lattice constant, the first III-V material has a first bandgap and the lattice constant, the second III-V material has a second bandgap and the lattice constant, and the channel material bandgap, the second bandgap, and the first bandgap form a monotonic sequence of bandgaps.

A computing device, comprising:

• a processor;
• and
• a memory device coupled to the processor, wherein the memory device or the processor includes a transistor comprising:
• a substrate;
• a channel area above the substrate and including a channel III-V material;
• and
• a source area above the substrate including a first portion and a second portion of the source area, wherein an interface between the channel area and the source area includes the channel III-V material, the second portion of the source area is adjacent to the interface between the channel area and the source area, the first portion of the source area is separated from the interface between the channel area and the source area by the second portion of the source area, the first portion of the source area includes a first III-V material, and the second portion of the source area includes a second III-V material, and wherein the channel III-V material has a channel material bandgap and a lattice constant, the first III-V material has a first bandgap and the lattice constant, the second III-V material has a second bandgap and the lattice constant, and the channel material bandgap, the second bandgap, and the first bandgap form a monotonic sequence of bandgaps.