| 摘要 |
PURPOSE:To prevent crystal defects, by making the thickness of the edge part of an Si3N4 film pattern larger and by reducing stress at the time of oxidation treatment. CONSTITUTION:An Si3N4 film 12 is provided on an Si substrate 11. An SiO2 film 13 is used as a mask to etch the former film 12 to reduce its thickness by half. The mask 13 is removed. An SiO2 mask 14 is produced. An opening is made in the Si3N4 film 12. The mask 14 is removed. At that time, the thickness of the edge part of the film 12 is larger than that of its other part. High-temperature treatment with humidification is then effected to produce an SiO2 film 15 with high accuracy on the exposed part of the substrate 11. Since the film 15 is not protruded, snapping is not caused. Since the thickness of the central part of the mask 12 is small, no crystal defects are caused and a selectively oxidized film of high reliability is manufactured. As a result, the degree of integration can be enhanced. |
