Method for forming gate oxide layers of various predefined thicknesses

摘要

A method is provided for use in semiconductor fabrication processes for forming a plurality of gate oxide layers with various predefined thicknesses in mixed-mode or embedded circuits that are formed in a semiconductor substrate. In particular, the gate oxide layers of various predefined thicknesses are formed by means of separated growth, which allows all the gate oxide layers to be each formed in one single step, instead of combining two or more oxide layers as in conventional processes, so that the thicknesses can be more easily controllable to the desired levels. The quality of the thus-formed gate oxide layers can thus be better assured.