Method of manufacturing a semiconductor device having field oxide regions formed through oxidation

Abstract

Abstract A method of manufacturing a semiconductor device includes forming field oxide regions (17) in a surface (1) of a silicon body (2) through oxidation, which body is provided with an oxidation mask (15) formed in a layered structure provided on the surface with a lower layer (4) of silicon oxide, an intermediate layer (5) of polycrystalline silicon and an upper layer (6) of a material including silicon nitride in which windows (8) are etched into the upper layer. The intermediate layer is etched away inside the windows and below an edge (10) of the windows, a cavity (11) is formed below the edge, and a material including silicon nitride is provided in the cavity. The material including silicon nitride is provided in the cavity while the surface of the silicon body situated inside the windows is still covered by a layer of silicon oxide, preferably with the lower layer of the layered structure. Field oxide regions can be provided in this way having the same dimensions as the photoresist mask (7) used for etching the window into the upper layer, while in addition a gate oxide (22) free from defects can be provided on the active regions (21) of the silicon body situated between the field oxide regions.

Inventors

• 👤 Paulus A. van der Plas
• 👤 Nicole A. H. F. Wils
• 👤 Andreas H. Montree

Bibliographic Details