“…[20][21][22] In the case of fluctuation of gate-leakage current of an SRAM cell, the gateoxide thickness of a 90-nm-node SRAM cell is less than 2 nm; therefore, leakage current through the gate oxide is due to direct tunneling, and it fluctuates at an amplitude greater than 1 nA. 20,21) In regard to trap-assisted tunneling current of a MOS capacitor with gate oxide thicker than 5 nm, fluctuation of stress-induced leakage current (SILC 23) ), called "variable SILC" (V-SILC), has been reported. 22) V-SILC is considered to be a possible origin of erratic bits, such as moving bits, [24][25][26][27] fast bits, 28) and anomalous cells, 29,30) in advanced floating-gate-type flash memories.…”