Characterizations of Hf_xMo_yN_z alloys as gate electrodes for n- and p-channel metal oxide semiconductor field effect transistors

In this article, the work functions (Φ_m) of hafnium-molybdenum (Hf_xMo_y) alloys were modified using nitrogen in dc reactive cosputtering for the first time. The Hf _xMo_yN_z alloys show low resistivity and excellent thermal stability up to 900°C. In addition, the work functions (Φ_m) of the Hf_xMo_yN_z alloys were tuned from the conduction band (4.17 eV) to the valence band (5.16eV) by increasing the nitrogen flow ratio. From the X-ray diffraction (XRD) data, the MoN(200) peak can be observed for samples with a nitrogen ratio higher than 6%, which was responsible for the work function (Φ_m) increase in the Hf_xMo_yN_z alloys.