Physics-Based Hot-Carrier Degradation Modeling

Abstract

We present a thorough analysis of physics-based hot-carrier degradation (HCD) models. We discuss the main features of HCD such as its strong localization at the drain side of the device, the weakening of the degradation at higher temperatures, and the change of the worst-case condition in small devices. The first feature is related to "hot" carriers, while the second is controlled by the fraction of "colder" particles. The latter feature is related to the change of the silicon-hydrogen bond-breakage mechanism from the single- to multiple-carrier process. All these findings suggest that the interface state creation process is controlled by the manner how the carriers are distributed over energy, that is, by the carrier energy distribution function. We distinguish between three main aspects of the physical picture behind hot-carrier degradation: carrier transport, microscopic mechanisms of defect creation and simulation of degraded devices. Therefore, we analyze and classify the existing HCD models in this context. Finally we present our hot-carrier degradation model based on a thorough evaluation of this distribution function by means of full-band Monte-Carlo device simulator. Our approach tries to address the whole hierarchy of physical phenomena in order to capture all the essential aspects of hot-carrier degradation.