1. A method implemented in a computer infrastructure having computer executable code tangibly embodied on a computer readable storage medium having programming instructions operable to: receive a number m of individual devices within an ensemble device; identify a sub-threshold slope; determine an uplift factor; separate random variation in a logarithm of a leakage current into a correlated random component and an uncorrelated random component; determine a first standard deviation of the correlated random component for the ensemble device; determine a second standard deviation of the uncorrelated random component for the ensemble device; generate a statistical model for electrical features of the ensemble device, based on the number m of individual devices, the sub-threshold slope, the uplift factor, the first standard deviation, the second standard deviation, and statistical random variables; and determine the electrical features of the ensemble device based on the statistical model for use in fabrication of integrated chips for semiconductor manufacturing.