A gate electrode structure may be formed on the basis of a silicon nitride cap material in combination with a very thin yet uniform silicon oxide based etch stop material, which may be formed on the basis of a chemically driven oxidation process. Due to the reduced thickness, a pronounced material erosion, for instance, during a wet chemical cleaning process after gate patterning, may be avoided, thereby not unduly affecting the further processing, for instance with respect to forming an embedded strain-inducing semiconductor alloy, while nevertheless providing the desired etch stop capabilities during removing the silicon nitride cap material.