High performance nMOSFET with HfSi/subx//HfO/sub 2/ gate stack by low temperature process

We propose HfSi
_x
/HfO
₂
gate stacks as the most suitable combination for high performance nMOSFETs. An equivalent work function (WF) to n
⁺
poly-Si was obtained by controlling Hf/Si ratio of the electrode. The highest electron mobility ever reported was achieved in the thinner Tinv region down to 1.6 nm by low temperature process without using plasma nitridation both for metal and high-k fabrication. As a result, the extremely high drive current of 1.25mA/mum at off-state leakage of 1 nA/mum and low gate leakage current of 0.3A/cm
²
were obtained at Vdd = 1.3V with 65 nm gate length nMOSFETs without strain enhanced technology