Vth fluctuations due to random telegraph signal on work function control in Hf-doped silicate gate stack

摘要

We investigated V_th fluctuations due to random telegraph signal (RTS) on gate work function control in Hf-doped silicate gate stack compared with the conventional impurity doping. Complex RTS were recognized for both n- and p-MOSFET. The WFC does not appreciably affect V_th fluctuations for n-and p-MOSFET. However, dopant contributes to V_th fluctuation, especially for the p-MOSFET. We found it is caused by change in V_fb fluctuation due to increase of the trap density.