| 摘要 |
PURPOSE:To realize sufficient withstand voltage and sufficient low values of Rs even with gate lengths of 0.5mum or less by a method wherein a gate electrode is chemically etched in a slight amount. CONSTITUTION:First an n type active layer 12 is formed on the surface of a semi-insulator GaAs substrate 11, and further a tentative gate electrode 13 is formed. Next, an n<+> layer 14 is ion-implanted with the mask of the tentative gate electrode 13, and annealing is carried out after a coat of annealing protection film 15. Then, after removal of the annealing protection film 15, the electrode 13 is made slightly smaller than original by slight chemical etching. The whole surface is coated with a photo resist film 16, and the electrode 13 is exposed by removing the photo resist film 16 located thereon. This electrode 13 is removed by chemical etching, and the photo resist film 16 is lifted OFF by evaporating a gate metal 18 from above, thereby forming a gate electrode 19. |
