Semiconductor resistors formed at a lower height level in a semiconductor device comprising metal gates

Abstract

In sophisticated semiconductor devices comprising high-k metal gate electrode structures formed on the basis of a replacement gate approach, semiconductor-based resistors may be provided without contributing to undue process complexity in that the resistor region is recessed prior to depositing the semiconductor material of the gate electrode structure. Due to the difference in height level, a reliable protective dielectric material layer is preserved above the resistor structure upon exposing the semiconductor material of the gate electrode structure and removing the same on the basis of selective etch recipes. Consequently, well-established semiconductor materials, such as polysilicon, may be used for the resistive structures in complex semiconductor devices, substantially without affecting the overall process sequence for forming the sophisticated replacement gate electrode structures.