Effect of reverse body bias on hot-electron-induced punchthrough reliability of pMOSFETs with thin gate dielectric at high temperatures

摘要

The effect of the reverse body bias V-SB on the hot-electron-induced punch-through (HEIP) reliability of pMOSFETs with a thin gate dielectric at high temperatures was investigated for the first time. Experimental results indicate that the reverse V-SB increased the HEIP degradation for a thin pMOSFET because of the increase in the maximum electric field E-m due to the increase in the threshold voltage V-th. The sensitivity of HEIP degradation to V-SB increased with increasing body effect coefficient gamma at a given oxide thickness T-ox. However, a thin device (22 angstrom) showed a much stronger dependence of HEIP degradation on V-SB due to the decrease in the velocity saturation length l, although it had a smaller. than a thick device (60 angstrom). These new observations suggest that the body bias technique for improving circuit performance can cause a reliability problem of nanoscale pMOSFETs at high temperatures and impose a significant limitation on CMOS device scaling. (C) 2016 The Japan Society of Applied Physics