| 摘要 |
PURPOSE:To prevent disconnection in a metallic interconnecting layer due to difference of levels, by performing a two-step etching process for forming an opening for Schottky barrier diode in a phosphorus-containing glass film, such that the glass film is isotropically etched until the thickness thereof is halved approximately in the first step and then the rest is etched anisotropically in the second step. CONSTITUTION:A semiconductor substrate 1 of one conductivity type is provided with a well 2 of the opposite conductivity type on a principal face thereof. A field oxide film 4 is formed selectively on the surface of the well 2 so as to isolate an element forming region from a contact region, and a first insulating film 3 is provided on the surface of the well 2 surrounded by the field oxide film 4. Then, a phosphorus- containing glass layer 8 is deposited all over the field oxide film 4 and the first insulating film 3. The phorophorus-containing glass layer 8 located on the element forming region is etched isotropically until its thickness is reduced to about a half. Subsequently, the rest of the phosphorus-containing glass layer 8 is removed by anisotropic etching to form an opening having a crateriform cross section. The first insulating film 3 exposed on the element forming region is removed by isotropic etching. In this manner, disconnection of a metallic interconnecting layer can be prevented effectively. |
