Patent ID: 6867439
Filing Date: 2005-03-15
Classification: H01L

Abstract:
1. A high electron mobility transistor us a Group III-V compound semiconductor, comprising: an undoped second channel layer laminated on an InP substrate via a buffer layer; an undoped first channel layer laminated on said second channel layer; and an electron-supplying layer laminated in contact with said first channel layer, wherein said first channel layer is composed of In said second channel layer is composed of a Group III-V compound semiconductor using a Group V element other than P, has an energy level of conduction band higher than that of the first channel layer, has a band gap wider than that of the first channel layer, and has a thickness larger than that of the first channel layer, wherein said first and second channel layers are formed to have a thickness small enough to have discrete quantum levels, a first quantum level with the lowest energy level being formed only in the first channel layer, and a second quantum level with the second lowest energy level being formed in both the first and second channel layers.