| 摘要 |
PURPOSE:To facilitate the adjustment of transistor characteristics by a method wherein a transparent insulating gate type control electrode is provided on duplicated layers of semiconductors with different electron affinity. CONSTITUTION:A GaAs layer 2 not containing impurity is provided on a semi- insulating GaAs substrate 1 containing Cr or the like and AlGaAs 3 containing N type impurity is further provided thereon. The surface of layer 3 is oxidized to form the insulative film 7 comprising Al2O3 and Ga2O3 and further Al thin film 8 around 100Angstrom thick seeking for transparency. The electron mobility and pinch off voltage may be improved by means of radiating this high mobility transistor held at low temperature around 77 deg.K from electromagnetic wave such as incandescent light or the like. Besides, a hole in electron donative layer 3 may be eliminated to restore the characteristics by means of impressing positive voltage on the control electrode 8. |
