Manufacture of memory cell

Abstract

Abstract PURPOSE:To prevent the shortage of the channel region of a transistor by forming an Si3N4 film on a capacitor when forming a dynamic memory cell formed of a transistor and a capacitor and forming polycrystalline Si electrode only thereon. CONSTITUTION:An SiO2 film 50 is covered on a P<-> type Si substrate 10, <+>B ions are injected therethrough, and a shallow P<+> type layer 52 is formed on the surface layer of the substrate 10. Subsequently, the Si3N4 film 54 is formed only on the capacitor C forming region, is heat treated, and a thick field SiO2 film 56 raised with a layer 52 around the film 54 is formed while retaining the layer 52 under the layer 54. Thereafter, with resist film 58 formed at the end of the film 54 as a mask the film 56 is etched and removed, and a thick film 56 is retained at the end 40 of the film 50 under the film 54. Thereafter, the film 58 is removed, an Si layer is epitaxially grown on the entire surface, monocrystalline layer 36 for forming the source and drain regions are formed on the exposed substrate 10, and a polycrystalline Si electrode layer 38 which is not extended by the film 56 is formed on the film 54.

Inventors

• 👤 Akira Takei

Bibliographic Details