Patent ID: 7285794

Claim:
A quantum semiconductor device comprising: a first semiconductor layer formed over a substrate and having a two-dimensional carrier gas formed in; a quantum dot formed over the first semiconductor layer; a second semiconductor layer formed over the first semiconductor layer, burying the quantum dot; a dot-shaped structure formed on the surface of the second semiconductor layer at a position above the quantum dot; a gate electrode electrically connected to the dot-shaped structure; source/drain regions formed in the second semiconductor layer on both sides of the quantum dot; and oxide layers formed on both sides of the dot-shaped structure on the upper surface of the second semiconductor layer, wherein depletion regions are formed in regions of the first semiconductor layer, which are below the oxide layers, the depletion regions define a channel region, and the source/drain regions are connected to both ends of the channel region, and the dot-shaped structure is caused to form on the surface of the second semiconductor layer at a position above the quantum dot due to crystal strains generated in the surface of the second semiconductor layer due to the presence of the quantum dot.