V_(TH) 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.