Measurement of Subthreshold Current Variability at 1.5 K Using Addressable MOSFET Array

Variability of 65 nm bulk MOSFETs in subthreshold region was measured at 300 K and 1.5 K using addressable transistor arrays. It was confirmed that variability of current onset voltage (COV) significantly increases at 1.5 K. It is shown that the cut-off performance of the FETs at 1.5 K is governed by variability of subthreshold current including COV, rather than steep minimum subthreshold slope.