Modeling of mismatch and across-chip variations in compact device models

Abstract

Pelgrom characterized device mismatch between two devices separated by a finite distance Dij as (a2 /WL + b2 D ij2) While the modeling of adjacent mismatch (D ij ≈ 0) in compact models is straightforward, the modeling of distance-dependent mismatch {Dij > 0) among several devices remains a challenge. Further, mismatch and intra-die/across-chip variations (ACV) are generally treated as two separate problems. In this paper, for the first time, we (i) link characterizations among adjacent mismatch, finite-distance mismatch, ACV, and correlation into a unified concept and description and improve Pelgrom's mismatch characterization, (ii) highlight the challenges in implementing Pelgrom's distance-dependent mismatch characterization in compact models, and (iii) present a set of compact solutions for modeling mismatch and ACV.