| 摘要 |
PURPOSE:To equalize the gate cut-off voltage by a method wherein an n<+> conductive layer at high concentration to be source and drain part near a gate electrode is selfmatchingly formed with high precision and excellent reproducibility without diffusing a gate metal in an operating layer. CONSTITUTION:A plasma silicon nitride film 23 as a protecting film is grown on a high resistance GaAs substrate 4 implanting Si<+> ion therethrough to form an N type opening layer 5. A silicon oxide film 21 is evaporated and another plasma silicon nitride film 22 is grown to form a pattern covering the peripheral part of the pattern 22 and the N type opening layer 5 to be a gate part on said layer 5. Firstly the film 21 is etched to form the gate pattern 21 further forming a high concentration conductive layer 6 by ion implanting process. Secondly overall surface is covered with a plasma nitride film 24 and after coating and drying up a photoresist film 26, overall surface is etched and the residual photoresist film 26 is removed to form electrodes 1-3. In such a constitution, gate metal may be prevented from diffusing in the operating layer as well as the gate Schottky characteristics from deteriorating to equalize the gate cut-off voltage. |
