| 摘要 |
PURPOSE:To form a recess on a substrate field region by thermally oxidizing a mask layer on an active region as a mask to form a thick oxide film on the surface of the substrate of the region to become a field, and then removing the oxide film. CONSTITUTION:A thin silicon oxide film 12 is thermally grown on the surface of a silicon substrate 11, a nitride film 13 is formed by a CVD thereon, and a nitride film 13 except the active region and a silicon oxide film 12 are then selectively removed. Then, with the film 13 as a thermal oxide mask the substrate 11 is thermally oxidized to form an oxide film 14 of approx. 2,000Angstrom on the surface of the substrate. Thereafter, the film 14 is removed by an etchant of fluoric acid to form a recess 15 on the field region of the substrate 11. |
