| 摘要 |
PURPOSE:To improve reproducibility and controllability by a method wherein the first and second metallic films having thermal resistance are successively formed, the source and drain regions are formed by implanting donor ions with the second metallic film as the mask, and the donor ions are activated by removing only the second metallic film. CONSTITUTION:An active layer 22 serving as the channel part of a field effect transistor is kept formed by selectively implanting the donor ions onto a GaAs semi-insulation substrate 21. The W film 23 and the Ni film 24 are successively deposited over the entire surface by electron beam vapor deposition method. The Ni film 24 and the W film 23 are etched by ion milling method with a photo resist 25 as the mask, resulting in the perfect removal of the Ni film 24, and accordingly the W film 23 is etched about half. When plasma etching is performed, the Ni film 24 and the GaAs semi-insulation substrate 21 are not at all affected, but only the W film 23 is etched. The donor ions are implanted at high density, resulting in the formation of N<+> implanted layers 26, the Ni film 24 is removed by chloric acid, and heat treatment is performed by covering the entire surface with an insulation film. |
