Variability aware simulation based design-technology cooptimization (DTCO) Flow in 14 nm FinFET/SRAM cooptimization
Abstract
In this paper, we use an automated tool flow in a 14 nm CMOS fin-shaped field-effect transistor (FinFET)/ static random access memory (SRAM) simulation-based design-technology cooptimization (DTCO) including both process-induced and intrinsic statistical variabilities. A 22 nm FinFET CMOS technology is used to illustrate the sensitivity to process-induced fin shape variation and to motivate this paper. Predictive Technology Computer Aided Design (TCAD) simulations have been carried out to evaluate the transistor performance ahead of silicon. Draft-diffusion simulations calibrated to the ensemble Monte Carlo simulation results are used to explore the process and the statistical variability space. This has been enabled by the automation of the tool flow and the dataset handling. The interplay between the process and the statistical variability has been examined in details. A two-stage compact model strategy is used to capture the interplay between process and statistical variability. To close the DTCO loop, the static noise margin and write noise margin sensitivity to cell design parameters and variability in FinFET-based SRAM designs are studied in details.