Impact of subthreshold hump on bulk-bias dependence of offset voltage variability in weak and moderate inversion regions

This paper analyzes impact of subthreshold hump on bulk-bias dependence of offset-voltage variability σ(ΔVg) in weak and moderate inversion regions. In nanometer scaled MOSFET with STI structure, full suppression of subthreshold hump is difficult. As a result, σ(ΔVg) behavior differs for every wafer also at operation current level of sub μA. By using ring gate structure, we have found that bulk-bias dependence of σ(ΔVg) becomes predictable even at operation current level of sub nA.