Method for forming semiconductor integrated circuit microelectronic fabrication having multiple gate dielectric layers with multiple thicknesses

Abstract

Within a method for forming a series of gate dielectric layers having a plurality of thicknesses upon a semiconductor substrate, there is sequentially selectively stripped only a series of sacrificial gate dielectric layers only in locations where new gate dielectric layers are desired to be formed, rather masking a only a portion of a partially sacrificial gate dielectric layer which is desired to be retained and stripping a sacrificial remainder of the gate dielectric layer. By employing the sequential selective stripping method, a semiconductor integrated circuit microelectronic fabrication is formed with enhanced reliability insofar as there is attenuated over etching into isolation regions which separate active regions of a semiconductor substrate.