Comparison and distribution of minimum operation voltage in fully depleted silicon-on-thin-buried-oxide and bulk static random access memory cells

The minimum operation voltage (V_min) of intrinsic channel fully depleted (FD) silicon-on-thin-buried-oxide (SOTB) static random access memory (SRAM) cells are measured and compared with those of conventional bulk SRAM cells in order to directly compare the worst cells. It is confirmed that the worst V_min of 1 kbit SOTB SRAM cells is half that of 1 kbit bulk cells. The distribution of V_min of 48 kbit SOTB and bulk SRAM cells are also measured and compared. The results show a great advantage of SOTB SRAM cells for lower power and lower voltage operation upon introducing SOTB, because of reduced V_TH variability.