Semiconductor device including a gate electrode on a protruding group III-V material layer and method of manufacturing the semiconductor device

A method of manufacturing a semiconductor device, the method comprising:

• forming a base insulation layer on a substrate;
• exposing a portion of the substrate;
• forming a group III-V material layer on the exposed portion of the substrate, the group III-V material layer having a portion that protrudes above the base insulation layer;
• forming a barrier layer, on the group III-V material layer, the barrier layer covering the side and upper surfaces of the protruding portion of the group III-V material layer and having a bandgap larger than that of the group III-V material layer;
• forming a gate insulation film on the barrier layer;
• forming a gate electrode on the gate insulation film;
• and
• forming source and drain electrodes spaced apart from the gate electrode on the group III-V material layer,
• wherein the overall composition of the group III-V material layer is uniform;
• wherein the protruding portion of the group III-V material layer is substantially defect-free;
• and
• wherein the source and drain electrodes are formed to physically contact the barrier layer and the gate insulation film.

A semiconductor device comprising:

• a substrate;
• at least two insulation layer portions spaced apart on the substrate;
• a group III-V material layer filling the space between the insulation layer portions, the group III-V material layer including a portion protruding higher than the insulation layer portions;
• a barrier layer covering the side and upper surfaces of the protruding portion of the group III-V material layer and having a bandgap larger than a bandgap of the group III-V material layer;
• a gate insulation film covering the surface of the barrier layer;
• a gate electrode on the gate insulation film;
• and
• source and drain electrodes disposed apart from the gate electrode,
• wherein the overall composition of the group III-V material layer is uniform;
• wherein the protruding portion of the group III-V material layer is substantially defect-free;
• wherein the source and drain electrodes physically contact the barrier layer and the gate insulation film;
• wherein the barrier layer comprises a group III-V material forming a quantum well;
• and
• wherein the group III-V material layer is a compound semiconductor layer including at least one group III element and at least one group V element.