| 摘要 |
PURPOSE:To suppress expansion of electron distribution in an electron storing layer by a crystal layer and to suppress the mobility of electrons, by providing a p type semiconductor crystal layer at least at a part between input and output electrodes and between a semi-insulating substrate and an electron running layer. CONSTITUTION:On a semi-insulating GaAs substrate 21, a p type GaAs single crystal 22 is selectively grown by, e.g., a molecular epitaxy (MBE) method with Zn as inpurities to a thickness of 400Angstrom . Then a GaAs single crystal layer 23, in which impurities are not doped, is grown by the MBE method to a thickness of 1mum from the semi-insulating GaAs substrate 21. On the layer 23, an Al0.3Ga0.7 As layer 24 and an electron supplying layer 25 are grown. When the p type GaAs single crystal 22 is provided in the vicinity of a drain electrode 28 of the running layer 23, the electron mobility can suppress the expansion of the electron density distribution caused by a reverse bias voltage between a control electrode 26 and the drain electrode 28. The electron mobility is improved by 1.5-2 times the electron mobility in conventional structures. |
