Patent ID: 6635945
Filing Date: 2003-10-21
Classification: H01L

Abstract:
A semiconductor device, which comprises being produced by forming a pad oxide film on the circuit-forming side of a semiconductor substrate; forming an oxidation prevention film on the pad oxide film; removing the oxidation prevention film and the pad oxide film at a desired position, thereby exposing the surface of the semiconductor substrate; horizontally recessing the pad oxide film; etching the exposed surface of the semiconductor substrate in a T/R ratio of 1.5-2.5 by isotropic etching, where T is a horizontally recessing amount of the pad oxide film and R is an etching amount of the exposed surface of the semiconductor substrate, after said horizontally recessing the pad oxide film; after the isotropic etching, forming a trench to a desired depth, using said oxidation prevention film as a mask; horizontally recessing the pad oxide film; oxidizing the trench formed in the semiconductor substrate; embedding an embedding isolation film in the oxidized trench; removing the embedding isolation film formed on the oxidation prevention film; removing the oxidation prevention film formed on the circuit-forming side of the semiconductor substrate; and removing the pad oxide film formed on the circuit-forming side of the semiconductor substrate, whereby upper edges of the trench are round.