Patent ID: 6265743
Filing Date: 2001-07-24
Classification: H01L

Abstract:
A trench type element isolation structure comprising: (a) an imbedded oxide film projecting upward from a silicon substrate surface and being imbedded in a groove formed on said silicon substrate through (b) a thermal oxidation film, said thermal oxidation film comprising:first thermal oxidation film portion formed higher than said silicon substrate surface; anda second thermal oxidation film portion formed on the surface of said groove lower than said silicon substrate surface, wherein each of the film thicknesses of said first thermal oxidation film and said second thermal oxidation film has an overhang part gradually overhanging outward in the vicinity of said silicon substrate surface, so that the film thicknesses of said second and first thermal oxidation film portions in a direction perpendicular to a wall of said groove are maximized in the vicinity of said silicon substrate surface.