| 摘要 |
PURPOSE:To limit the extent of a press-in diffusion range 8 by, after stacking SiO, Si3N4 and SiO2 films on a semiconductor substrate making an opening in the uppermost layer SiO2 film of thus-obtained structure and a opening layer by 0.5-2mum than the opening in the Si3N4 film under the SiO2 film, making ion injection using the openings as mask. CONSTITUTION:An SiO2 film 2 is produced on the surface of an Si substrate 1 by thermally oxidizing the substrate 1, an Si3N4 film and an SiO2 film are let make vaporous-phase growth on the SiO2 film 2 and an opening 6 is formed by the selective etching using a reactive ion. Next, An opening larger than the opening 6 by 0.5-2mum is formed in the film 3 exposed in the opening by repeating etching again, a resist film 9 is removed and an impurity ion is injected through the film 2. Thereafter, an SiO2 film 7 is generated in the large opening through selective oxidation and at the same time a press-in diffusion region 8 limited by the film 7 is generated thereunder. |
