| 摘要 |
PURPOSE:To reduce the gate length beyond photolithography by a method wherein the first thin film is formed very fine beyond photolithography and replaced with a gate. CONSTITUTION:An insulation film 4 and a resist film 7 formed on the surface of a compound semiconductor substrate 1 are removed so that only an insulation film 6 (first thin film) called 'side wall' may remain on the surface of this substrate 1. Next, an Si3N4 insulation film (second thin film) 9 is formed on this substrate 1, and a resist film 10 is formed on the surface of the substrate 1 by spin-coating or the like. Thereafter, the resist film 7 is thinned by etching, thus exposing the small projection of the insulation film 9 over the insulation film 6. Then, the top of the insulation film 6 that is the first thin film is exposed by etching the exposed projection of the insulation film 9. Besides, the SiO2 insulation film 6 is removed by etching with the mask of the insulation film 9. |
