| 摘要 |
PURPOSE:To enable a heterojunction semiconductor device to operate at a high speed by using the heterojunction consisting of an InP layer and AlxGa1-xAsySb1-y (y=0.044X+0.52) layers. CONSTITUTION:An undoped InP layer 12, an undoped AlxGa1-xAsySb1-y layer 13 and an Si-doped N<+>-type AlxGa1-xAsySb1-y layer 14 are made to grow in order on a semiinsulative InP substrate 11 and electrodes 15, 16 and 17 are provided on the layer 14. According to this constitution, as the electron affinity of the InP layer is large, electrons, which are fed by donors in the layer 14, are attracted to the side of the InP layer and an electron accumulated layer is formed. As an impurity is not doped in the layer 12, the effect of the formation of the electron accumulated layer is large in the low-temperature layer 12, wherein a scattering of the ionized impurity becomes dominative, and a high-electron mobility is obtainable. Moreover, the InP layer can take a high impressing voltage as the threshold electric field thereof is high and the peak- electron rate thereof is large. |
