| 摘要 |
PURPOSE:To realize a capacitor free of voltage-withstanding capability degradation and capable of long-standing reliability by a method wherein an insulating film with an opening is provided on a semiconductor substrate and serves as a mask in a dry- etching process whereby an groove is provided, an epitaxial layer is grown on the groove bottom and side wall to reach as far as the substrate surface, and, on the epitaxial layer, a capacitor electrode is installed with an intermediary of another insulating film. CONSTITUTION:On an Si substrate 1, a glass film with its main component SiO2 or synthetic resin is formed to serve as a mask 2 provided with an opening. Directional dry etching is accomplished by using the plasma of a gas based on F or Cl for the provision of a groove 11. A process follows wherein the inner wall of the groove 11 is subjected to etching that is accomplished only lightly, an epitaxial layer is grown, by using SiH4 or the like, to extend from the bottom of the groove 11 to its side wall to the surface of the Si substrate 1. The epitaxial layer develops into an epitaxial layer 3 with its surface very flat, flattening the inner wall with its surface rugged with protrusions and pits. After this, on the epitaxial layer 3 through the intermediary of an insulating film 4 consisting of SiO2, Si3N4, or the like a capacitor electrode 5 is built by deposition of polycrystalline Si. |
