Ultra-thin Ta2O5/SiO2 gate insulator with TiN gate technology for 0.1 mu m MOSFETs

We have developed a new Ta2O5/SiO2 gate insulator with a TiN gate electrode technology to break through the limitation of a thin SiO2 gate insulator with a poly-Si electrode. Wa successfully fabricated nMOSFETs with stable operation and high drive current for the first time. Ultra thin chemically oxidized SiO2 (less than 2 nm) combined with Ta2O5 provides a stable interface which improves Gm and reliability of transistor. High drive current (Idmax = 0.74 mA/mu m at Vg = Vd = 3.0V) and good sub-threshold slope (S-factor = 76 mV/dec.) were obtained with Teq of 2.8nm and gate length of 0.35 mu m nMOSFETs.