| 摘要 |
PURPOSE: To reduce the resistance and parasitic capacitance of a fine gate by irradiating the upper and lower parts of the gate with an electron beam having different intensity of energy. CONSTITUTION: A two-dimensional electron gas layer 2, an AlGaAs layer 3 and a doped Schottky layer, i.e., a cap layer 4, are formed sequentially on a substrate 1 followed by formation of ohmic layers 5a, 5b. A resist 6 is then applied to the cap layer 4 and heat treated. Subsequently, a second resist 7 is applied onto the first resist 6 and an exposure step is executed using an electron beam having uneven energy. In order to form a T type gate, first and third electron beams 8a, 8c have energy of such intensity as exposing only the second resist 7 while a second electron beam 8b has energy of such intensity the first and second resists 6, 7 can be exposed entirely. |
