| 摘要 |
An active layer of a field effect transistor disposed on an InP substrate (101) comprises at least an InAs layer (105) and two InGaAs layers (104, 106). The InGaAs layer (104) is InxGa1-xAs (wherein 0.55 < x < 1) and the InGaAs layer (106) is InyGa1-yAs (wherein 0.55 < y < 1). The active layer comprises, for example, In0. 53Ga0. 47As layer (103) / In0. 8Ga0. 2As layer (104) / InAs layer (105) / In0. 8Ga0. 2As layer (106) / In0. 53Ga0. 47As layer (107). Electrons which have been leached out of the InAs layer (105) are confined into the InGaAs layers (104, 106), and about 90 % of the active electrons are accumulated in the layers (104, 105, 106) to achieve an excellent electron transport performance, so that an excellent high frequency characteristic can be obtained exhibiting a high cut-off frequency and an improved transconductance. <IMAGE> |
