| 摘要 |
PURPOSE:To obtain a high performance field effect transistor, by using polycrystalline Si instead of metal for a Schottky junction, doping phosphorus or arsenic in the polycrystalline Si, and making resistance low. CONSTITUTION:In a semi-insulating GaAs substrate 11, N-GaAS 12 and N<+> GaAs 13 are formed by ion implanting technology. Thereafter, heat annealing is performed in order to activate implanted Si ions. Then, polycrystalline Si 17 is deposited to a thickness of 2,000Angstrom by a sputtering method, and phosphorus ions are implanted to the polycrystalline Si. Thus the resistance of the polycrystalline Si 17 is made low. Thereafter, a gate pattern is formed so as to obtain a gate electrode. When the polycrystalline Si 17 and a photoresist film as masks, dry etching is performed. Thereafter, an insulating film SiO2 18 is formed by a thermal decomposition method using SiH4 gas. After a pattern, which is to become source and drain electrodes 15 and 16 is formed, an ohmic electrode is obtained. |
