| 摘要 |
PURPOSE:To improve characteristics by superposing first and second compound semiconductors in high concentration onto a substrate in low impurity concentration, forming a hetero-junction, shaping a Schottky gate electrode and using even a two-element electron gas in a section adjacent to the hetero-junction as a channel. CONSTITUTION:GaAs 2, Al0.3Ga0.7As 11 and n-type Al0.3Ga0.7As 12 are superposed onto a semi-insulator GaAs substrate 1 and employed as buffers, and n-type GaAs 3 is superposed through a non-added thin AlxGa1-xAs spacer 13. A Schottky gate electrode 4 consisting of Ti/Pt/Au and source-drain electrodes 5, 6 composed of AuGe/Ni are attached onto the layer 3. A two-element electron gas layer 15 is formed to an adjacent section by a difference between the electron affinity of the layers 12 and 3 in a hetero-junction shaped by the layers 12, 13, 3, a substantial channel is constituted together with an n channel in the layer 3, electron mobility mu in the substantial channel is increased, operation at high speed is enabled, and electronic concentration in the layer 3 adjacent to the hetero-junction 14 is also augmented, thus improving FET characteristics under the state in which a depletion layer 10 is pinched off. |
