1.5 nm direct-tunneling gate oxide Si MOSFET's

In this paper, normal operation of a MOSFET with an ultra-thin direct-tunneling gate oxide is reported for the first time. These high current drive n-MOSFET's were fabricated with a 1.5 nm direct-tunneling gate oxide. They operate well at gate lengths of around 0.1 /spl mu/m, because the gate leakage current falls in proportional to the gate length, while the drain current increases in inverse proportion. A current drive of more than 1.0 mA//spl mu/m and a transconductance of more than 1,000 mS/mm were obtained at a gate length of 0.09 /spl mu/m at room temperature. These are the highest values ever obtained with Si MOSFET's at room temperature. Further, hot-carrier reliability is shown to improve as the thickness of the gate oxide is reduced, even in the 1.5 nm case. This work clarifies that excellent performance-a transconductance of over 1,000 mS/mm at room temperature-can be obtained with Si MOSFET's if a high-capacitance gate insulator is used.