| 摘要 |
PURPOSE:To obtain a thin oxide film high in hydrophilic nature and free from contamination, by a method wherein when the thin oxide film is formed on the surface of a semiconductor substrate, a photosensitive resin pattern is provided on a film to be etched, which is provided on the substrate, and the film is etched through the resin pattern employed as a mask and is then exposed to a gas plasma containing oxygen, and then, the exposed film is treated with a solution. CONSTITUTION:An Si3N4 film 8 is formed by CVD on the surface of a semiinsulating GaAs substrate 7 provided with an N<+> type region 5 and an N<+> type region 6 for an ohmic contact which are formed by ion implantation. Then, a photosensitive resin 9 having an opening corresponding to the region 6 is provided on the entire surface of the film 8. With the resin 9 employed as a mask, the film 8 is etched by the gas plasma of Freon such as CF4 to expose the surface of the region 6. Thereafter, the surface of the substrate 7 is exposed to the O2 plasma for such a short time that the resin 9 is not substantially etched, that is for about 10sec, thereby to form on the surface of the region 6 a thin oxide film 10 with a thickness of about 50Angstrom . Then, an electrode 11 of an Au-Ge alloy 11 is provided on the oxide film 10. |
