| 摘要 |
PURPOSE:To improve the integration degree by eliminating bird beaks by a method wherein a buffer oxide film, an oxidation resistant film having an aperture in part, a field oxide film via aperture, and a selective etching coating film on the aperture are successively formed on a semiconductor substrate, and these films are removed by etching by using the coating film as a mask. CONSTITUTION:A thermal oxide film is formed on the Si substrate 21 and made as the buffer oxide film 22. An Si nitride film 23 is deposited thereon. The aperture 24 is provided by the method of photoetching. The field oxide film 25 is provided by steam oxidation of the substrate 21 from the aperture 24. The selective etching coating film 26 is deposited on the film 23 and the aperture 24. The film 26 is left only on the aperture 24 by RIE. The films 22 and 25 are etched by RIE. Since the polycrystalline film 26 serves as a mask, the field oxide film 25 is etched away only at the part of bird beak. Thereby, the integration degree improves. |
