Gate Oxide Reliability: Physical and Computational Models

Ensuring that the performance of a microelectronics product remains within the customer’s specifications for a long period of time, or, equally, predicting the working conditions of future generations that guarantee reliable operation becomes increasingly difficult as devices get smaller. The continuous reduction of the gate dielectric physical thickness has raised some questions about the capability of silicon dioxide to continue to meet reliability requirements in future technology generations. In order to address these issues, extensive physical modeling of silicon dioxide breakdown has been carried out to date. This chapter presents the current understanding about gate oxide intrinsic reliability, and discusses the resulting reliability projections. A number of models have been proposed, but a comprehensive model is still lacking. Here, the main physical models will be briefly illustrated. Their basic elements will be discussed in greater detail, with particular attention to possible numerical implementation. Reliability projections provided by different models are then compared to discuss silicon dioxide reliability limits.