| 摘要 |
PURPOSE:To reduce the crystal defects occurred in a semiconductor device during manufacturing of the device by defining the impurity density of a high density region in a boundary between a selective oxide film forming film and a silicon substrate and the thickness of a nitride film used therefor when isolating between the semiconductor elements with the oxide film. CONSTITUTION:An SiO2 film 1 of predetermined pattern is formed on a P-type Si substrate 2, and with the film 1 as a mask a plurality of N-type wells 3 are formed in the substrate 2. Then, the film 1 is removed, an SiO2 film and an Si3N4 film 5 having a thickness of less than 1,300Angstrom are sequentially laminated newly on the entire surface, a mask of a photoresist film 6 is formed thereon, and only the film 5 is selectively etched. Thereafter, with the film 5 as a mask a P-type channel- stopper region 7 is formed in the substrate 2 disposed in the well 3 through the film 4 by an ion implantation, the film 6 is then removed, the film 4 is buried with the SiO2 film 8 between the films 5, and the impurity density of the region 7 is simultaneously controlled to less than 10<18> atoms/cm<3>. Subsequently, the respective regions 9-11 are formed in the well 3 by the conventional method. |
