| 摘要 |
PURPOSE:To obtain electrodes which have preferable GaAs/Ga boundary and Ge/W-Al boundary even if activated and annealed after electrode materials are covered by constructing electrodes of W-Al film of high melting point metal and an N<++>Ge film due to As ion implantation disposed under the W-Al film when forming ohmic electrodes at an FET. CONSTITUTION:Two Ge films 2 are formed on the ohmically contacting surface of a semi-insulating GaAs substrate 1, the region except this is covered with Ni mask 4, N type ions are implanted to alter the film 2 into N<++> type film 2', and N<++> type region 5 is formed under the film 2'. Then, the mask 4 is removed, a resist film 6 is covered from the film 2' on the outside, and a shallow N type region 7 is formed by ion implanting on the surface layer of the substrate 1 surrounded by the film 2'. Then, the both ends of the region 7 are altered to the N<+> type region 11 connected to the region 5, a gate electrode 8a and an ohmic electrode 8b made of W-Al are mounted on the region 7 and the film 2, and the entire surface is protected with the SiO2 film 12. |
