Semiconductor device

Claim 1

In a semiconductor device using the quantum effect of one dimension, said device comprising a substrate, a first electrode formed under said substrate, a device structure selected from a quantum well structure, a superlattice structure, and a modulation-doped heterostructure disposed on said substrate, and a second electrode formed on said device structure, the device wherein said quantum effect of one dimension based on said device structure arises in the direction vertical to the plane of said substrate on which said device structure is disposed, and wherein the plane of said substrate is substantially the (111) plane, where said quantum well structure comprises successively a first cladding layer, a quantum well layer having a thickness of about 100 Å or less, and a second cladding layer; said superlattice structure including a multiple well structure comprises a first cladding layer, a multi-layered well layer comprising alternate layers of well layers and barrier layers having a thickness of about 200 Å or less formed on said first cladding layer, and a second cladding layer formed on said multi-layered well layer; and said modulation-doped heterostructure comprises an undoped layer of a first semiconductor, an undoped spacing layer of a second semiconductor having a thickness of about 200 Å or less formed on said undoped layer, and a doped carrier supplying layer of the second semiconductor formed on said undoped spacing layer.