High performance 70 nm gate length germanium-on-insulator pMOSFET with high-k/metal gate

摘要

We demonstrate for the first time 70 nm gate length TiN/HfO_2 pMOSFETs on 200 mm GeOI wafers, with excellent performance: I_(ON) = 260 μAm and I_(OFF) = 500 nA/μm @ V_d = -1.0 V (without germanide). These performance are obtained using adapted counterdoping and pocket implants. We report the best CV/I vs. I_(OFF) trade-off for Ge or CeOI devices: CV/I = 4.4 ps, I_(OFF) = 500 nA/μm @ V_d = -1 V. Moreover, based on fine electrical characterizations (μ, D_(it), R_(access_, etc.) at T= 77-300 K, in-depth analysis of both ON and OFF states were carried out. Besides, calibrated TCAD simulations were performed to predict the performance enhancements which can be theoretically reached after further device optimization. By using germanide and reducing both interface state density and diode leakage we expect I_(ON) = 450 μA/μm, I_(OFF) = 100 nA/μm @ V_d = -1 V for L_g =70 nm.