Low voltage timing characterization of 40 nm standard cell library

Abstract

This master's thesis describes the creation and application of a simulation environment for characterizing the standard cell library for the 40-nanometer semiconductor manufacturing process. This is done by creating a workflow for industry-standard characterization software Cadence Liberate to generate timing models essential for digital circuit design. The core work included integrating the specific 40 nm process design kit data and configurating the necessary simulations to accurately simulate cell behaviour under various operation conditions.

A wide range of characterization simulations were executed with the Liberate environment. These included simulation runs covering standard combinations of process variations, operating voltages, and temperatures to create library models. To analyse complex temperature-related timing effects particularly at lower voltages the specific investigations were also performed through targeted sweep simulations across voltage and temperature. Key results from the characterization software were verified against Cadence Spectre circuit simulations to ensure accuracy and reliability of the generated standard cell library models.

The main outcome of this work was a validated characterization flow and set of generated timing models for the 40 nm standard cell library. The simulations provided detailed description how the cell delays respond to temperature changes, particularly at low voltage conditions where behaviour deviated from typical trends. Also, the statistical variations in timing across different manufacturing and operating conditions were analysed. This characterization work provided crucial data and models necessary for the accurate timing analysis and reliable design of complex integrated circuits using this technology.