| 摘要 |
PURPOSE:To form high concentration N<+> type conductive layers to be used as a source part and a drain part with high precision, having favorable reproducibility and by selfalignment up to the neighborhood of a gate electrode at a Schottky barrier gate field effect transistor. CONSTITUTION:A gate pattern 21 and a mask 22 to cover the peripheral part of an FET are formed on the plasma nitride film 23 of an N type active layer 5. The surfaces of the patterns 21, 22 thereof are covered with a silicon oxide film 24. Then only the amount of thickness of the oxide film 24 is removed according to parallel electrode type dry etching to leave the side walls 24 of the oxide film on the sides of the Mo gate pattern 21, and Si ions are implanted through the plasma nitride film 23 to form high concentration impurity layers 6 using the remaining side walls as masks. Then crystallinities of the active layer 5 and the high concentration conductive layers 6 are recovered by heat treatment, a silicon oxide film 26 is covered thereon as a coating film, and a photo resist film 27 is applied to be dried. Accordingly, the surface of the photo resist film 27 is smoothed, and the photo resist film 27 on the gate pattern 21 is thinned. The whole surface is etched according to parallel electrode type dry etching to expose the Mo gate pattern 21. |
