Predicting the effects of plasma-induced damage on p–n junction leakage and its application in the characterization of defect distribution

Abstract

Understanding the effects of defect creation during plasma exposure is crucial for designing future ultra-low leakage current devices. Created defects play a role as carrier conduction paths, leading to an increase in the p–n junction leakage current (ΔJpn). Herein, we propose a model focusing on the effects of created defects on ΔJpn in combination with technology computer-aided design simulations. Three different defect spatial distributions, ndam(x), (linear, exponential, and Gaussian) were implemented for predicting ΔJpn under various operating conditions. It was confirmed that ΔJpn is strongly dependent on ndam(x), in addition to the total number of defects and generally accepted energy levels. The prediction model was implemented to experimentally assign the profile of defects created by an emerging mechanism—lateral straggling of incident ions—under fluorocarbon-containing plasma exposure, which is commonly employed in electrical contact opening steps. Devices with various lateral p–n junction widths and contact opening areas were exposed to the plasma. The experimental results of ΔJpn revealed that the profile of defects in the lateral direction was exponential. The proposed model prediction scheme is useful for designing plasma processes and circuit layouts to realize future ultra-low leakage current devices.