论文信息 - Reduction of Vth variation by work function optimization for 45-nm node SRAM cell

Reduction of Vth variation by work function optimization for 45-nm node SRAM cell

Work function (WF) control is a key technology for the reduction of channel impurity concentration, which results in the decrease in intrinsic random dopant variation (IRDV). It is demonstrated that saturation Vth is affected not only by IRDV but also by S factor variation owing to fluctuation of DIBL. While channel impurity reduction by WF control decreases IRDV, DIBL is degraded in turn, and this enhances S factor variation. The optimal DeltaVFB by WF control is determined by two competing factors, S factor variation and IRDV. With this technique sigmaVth of 45-nm SRAM comparable to 65-nm, despite cell size reduction is obtained.

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