A MOS transistor array with pico-ampere order precision for accurate characterization of leakage current variation

Transistor array design for accurate sub-threshold current measurement is proposed. The proposed array achieves both compact layout area and pico-ampere order precision, which is particularly useful in off-state current variation characterization. The effect of masking current caused by the transistors that share the same measurement PAD is carefully eliminated using leakage cut-off switches and potential equalizing supply. Experimental array design consisting of 1023 low threshold voltage devices demonstrated accurate measurement of subthreshold leakage current with precision of 10-pA.