| 摘要 |
PURPOSE:To form a thin and uniformly thick resist layer and, e.g., to form an accurate mask for impurity region formation use on an uneven face of a semiconductor substrate by a method wherein, before the resist layer is formed, a substratum layer used to level and flatten an uneven part of the semiconductor substrate is formed. CONSTITUTION:V-grooves 2 are formed on the surface of an N<-> type silicon semiconductor substrate 1. Then, a liquid spin-coating material for SiO2 film formation use is spin-coated on the whole surface; it is dried; a substratum layer 3 is formed on the surface of the substrate 1; the surface is flattened. A resist layer 4 is formed on it; while a pattern film is applied, the layer is irradiated with light and exposed to light; it is removed selectively; a window 5 is opened. Since the resist layer 4 is thin and uniformly thick, an exposure operation can be executed satisfactorily; the window 5 can be opened as desired; a minute mask 6 can be completed. In succession, the substratum layer 3 is etched and removed selectively by using the mask 6. An N-type impurity is ion-implanted; the mask 6 and the substratum layer 3 are removed; an insulating layer 8 is formed on the surface of the semiconductor substrate 1; a polysilicon support layer 9 is formed on it; the rear of the semiconductor substrate 1 is polished; the bottom of the grooves 2 is exposed; thus an insulating-layer isolation substrate (D) is completed. |
