Patent ID: 6593175
Filing Date: 2003-07-15
Classification: H01L

Abstract:
A method of forming an oxide layer on a semiconductor layer, comprising:providing a substrate with the semiconductor layer, the semiconductor layer having a surface; depositing a mask layer with a predefined thickness over the semiconductor layer; forming an opening in the mask layer by patterning the mask layer so as to expose a portion of the surface of the semiconductor layer, the portion substantially coinciding with an area where the oxide layer is to be formed; performing an ion implantation step with a tilt angle with respect to the surface of the exposed portion of the substrate, thereby using the mask layer as an implantation mask so as to create an inhomogeneous ion concentration in the area of the exposed portion; and oxidizing the exposed portion of the substrate to form the oxide layer, wherein a thickness of the oxide layer in a region of increased ion concentration is reduced due to a reduced oxidation rate.