Threshold voltage tunability of p-channel metal oxide semiconductor field-effect transistor with ternary Hf_xMo_yN_z metal gate and Gd₂O₃ high-κ gate dielectric

p-channel metal oxide semiconductor field-effect transistor (pMOSFET) devices with a ternary HfxMoyNz metal gate and a Gd₂O₃ high-κ gate dielectric have been demonstrated for the first time. The nitrogen-concentration-control method is a simple and cost-effective technique for metal work-function modulation. HfxMoyNz thin films were cosputtered from pure hafnium (Hf) and molybdenum (Mo) targets in nitrogen (N2) and argon (Ar) mixtures. The HfxMoyNz thin films have low resistivity and high thermal stability up to 950 °C. The threshold voltage (Vth) of the HfxMoyNz/ Gd ₂O₃ pMOSFET can be tuned from -0:6 to -0:08 V by controlling the nitrogen flow ratio. Moreover, there is little negative bias temperature instability (NBTI) degradation of the HfxMoyNz/Gd₂O ₃ pMOSFET device. Compared with the Hf_xMo _yNz/SiO₂ pMOSFET, the Hf_xMo_yN _z/Gd₂O₃ pMOSFET has a small threshold voltage modulation owing to the extrinsic Fermi level effect at the HfxMoyNz and Gd ₂O₃ interface. A physical model has been proposed to explain the extrinsic Fermi level pinning effect of the Hf_xMo _yN_z/Gd₂O₃ pMOSFET device.