Method of forming an electrode with adjusted work function

Abstract

A method forms a gate stack for a semiconductor device with a desired work function of the gate electrode. The work function is adjusted by changing the overall electronegativity of the gate electrode material in the region that determines the work function of the gate electrode during the gate electrode deposition. The gate stack is deposited by an atomic layer deposition type process and the overall electronegativity of the gate electrode is tuned by introducing at least one pulse of an additional precursor to selected deposition cycles of the gate electrode. The tuning of the work function of the gate electrode can be done not only by introducing additional material into the gate electrode, but also by utilizing the effects of a graded mode deposition and thickness variations of the lower gate part of the gate electrode in combination with the effects that the incorporation of the additional material pulses offers.

Dependencies are inferred from the claim text.