Patent ID: 6734113
Filing Date: 2004-05-11
Classification: H01L,Y10S

Abstract:
A method for forming multiple oxide layers, comprising the steps of:forming a first gate oxide layer with a first predetermined thickness on a semiconductor substrate; forming a first masking layer on the first gate oxide layer, the first masking layer defining a first region of the first gate oxide layer; performing nitridation to a surface of a second region of the first gate oxide layer exposed by the first masking layer; removing the first masking layer; forming a second masking layer covering the first and the second regions of the first gate oxide layer but exposing a partial portion of the second region, the partial portion being defined as a third region of the first gate oxide layer; exposing a surface of the semiconductor substrate by etching the third region of the first gate oxide layer exposed by the second masking layer; and forming a second gate oxide layer with a second predetermined thickness on the exposed semiconductor substrate and the first region of the first gate oxide layer to thereby form a third gate oxide layer on the first region with a thickness combined of the first predetermined thickness and the second predetermined thickness.