arXiv subjects

Rohit Guttal

Publications and source records attributed to Rohit Guttal.

4 recordsLinked to original sources

arXiv2018

Modeling and Simulation of Electromigration Behavior for Via Array Structure

In this paper, we develop a analytical model and algorithm for calculating uneven current distribution in via array structures. We propose a stress time translation formula and cumulative failure distribution equation to model the memory effect of electro migration stress or damage on a via array structure. We develop a method to project via array electromigration (EM) lifetime based on an arbitrary via failure sequence, and demonstrate that the proposed via array EM lifetime distribution trend correlates well with experimental results.

physics.app-ph↗

arXiv2018

A Machine Learning Framework for Register Placement Optimization in Digital Circuit Design

In modern digital circuit back-end design, designers heavily rely on electronic-design-automoation (EDA) tool to close timing. However, the heuristic algorithms used in the place and route tool usually does not result in optimal solution. Thus, significant design effort is used to tune parameters or provide user constraints or guidelines to improve the tool performance. In this paper, we targeted at those optimization space left behind by the EDA tools and propose a machine learning framework that helps to define what are the guidelines and constraints for registers placement, which can yield better performance and quality for back-end design. In other words, the framework is trying to learn what are the flaws of the existing EDA tools and tries to optimize it by providing additional information. We discuss what is the proper input feature vector to be extracted, and what is metric to be used for reference output. We also develop a scheme to generate perturbed training samples using existing design based on Gaussian randomization. By applying our methodology, we are able to improve the design runtime by up to 36% and timing quality by up to 23%.

cs.LG↗

arXiv2017

Uneven Current Distribution Modeling and Random Walk based Variation Analysis for interconnect Electromigration Estimation

In this paper, we modeled and simulated uneven current distribution for on-die interconnect structure. We show significant difference when considering uneven current distribution. Finite Element Method approach is used to analyze various variation effects. Blech length effect and analytical EM lifetime calculation is used to quickly identify on-die EM weak wires. We propose a random walk based approach to evaluate on-die variation impact on electromigration reliability. Experimental results show substantial EM degradation with variation effects present.

physics.app-ph↗

arXiv2017

Chip-Level Electromigration Reliability Evaluation with Multiple On-Die Variation Effects

In this paper, we briefly introduce physical foundations of electromigration (EM) and present a few classical EMrelated theories. We discuss physical parameters affecting EM wire lifetime and we introduce some background related to the existing EM physical simulators. In our work, for EM physical simulation we adopt the atomic concentration balance-based model. We discuss the simulation setup and results. We present a variation-aware electromigration (EM) analysis tool for power grid wires. The tool considers process variations caused by the chemical-mechanical polishing (CMP) and edge placement error (EPE). It uses a compact model that features critical region extraction and variation coefficient calculation.

physics.app-ph↗