Impact of process variations and long term degradation on 6T-SRAM cells

[摘要] In modern deep-submicron CMOS technologies voltage scaling can not keep upwith the scaling of the dimensions of transistors. Therefore the electricalfields inside the transistors are not constant anymore, while scaling downthe device area. The rising electrical fields bring up reliability problems,such as hot carrier injection. Also other long term degradation mechanismslike Negative Bias Temperature Instability (NBTI) come into the focus ofcircuit design.

Along with process device parameter variations (threshold voltage, mobility),variations due to the degradation of devices form a big challenge fordesigners to build circuits that both yield high under the influence ofprocess variations and remain functional with respect to long term devicedrift.

In this work we present the influence of long term degradation and processvariations on the performance of SRAM core-cells and parametric yield of SRAMarrays. For different use cases we show the performance degradation dependingon temperature and supply voltage.

[学科分类] 电子、光学、磁材料