| 摘要 |
PURPOSE:To improve a yield rate by utilizing a process of forming an SiO2 film including impurities on a semiconductor layer in a substrate, a process of eliminating a desired part of the SiO2 film, a process of diffusing impurities, and a processing of forming a gate electrode and ohmic electrodes. CONSTITUTION:Si<+> ions are implanted in a semi-insulating GaAs substrate 1, and an operating layer 17 having a thickness against a desired pinch off voltage and carrier concentration is formed. An SiO2 film 18 including Sn is deposited thereon, and the SiO2 film 18 is etched in an inverted mesa shape with a resist 19 as a mask. The resist 19 is removed, an Si3N4 film 20 is formed on the entire surface, heat treatment is performed, and an ohmic region 21 is formed. The Si3N4 film 20 is removed, and Al 22 is evaporated. The SiO2 film 18 is removed, and an Al Schottky electrode 22 and the two AuGeNi ohmic electrodes 23 and 24 are formed. Thus the Schottky gate FET having excellent microwave characteristics and yield rate is obtained. |
