| 摘要 |
PURPOSE:To shorten the time required for production, especially for the growth of a semiconductor layer, by a method wherein a compound semiconductor buffer layer usually not doped is caused to have an N type compound semiconductor buffer layer buried at an appropriate depth. CONSTITUTION:On a GaAs substrate 1, an N type GaAs layer 7 is formed, whereon an undoped GaAs channel layer 4, undoped AlGaAs layer 5, N type AlGaAs electron supplying layer 6 are formed, in that order. In a semiconductor designed as such, donors within the N type compound semiconductor buffer layer a re ionized, which enables the potential to be lowered of the conduction band a short distance from the substrate. Accordingly, neither electron mobility nor electron concentration in the 2DEG layer will be harmed even when the buffer layer in its entirety is made thinner. |
