THE CURRENT-CARRYING CORNER INHERENT TO TRENCH ISOLATION

In this paper it is shown for the first time how the characteristics o f the corner MOSFET inherent to trench isolation can be extracted from hardware measurements and how the corner device must be taken into ac count when extracting MOSFET channel characteristics. For NFET's it is found that the corner's threshold voltage, substrate sensitivity, and sensitivity to well doping are all smaller than the channel's. The re sults imply that for low standby power logic applications requiring hi gh performance, it may become necessary to locally control the well do ping at the corner. However, the corner's reduced substrate sensitivit y and width independence can provide a significant advantage in a DRAM cell.