Homi E. Nariman

Effect of local interconnect etch-stop layer on channel hot-electron degradation

Routine use of an etch-stop layer during semiconductor processing favors circuit density and performance through the use of local interconnect and similar damascene processes, and also allows the use of manufacturable etch recipes. Previous studies have demonstrated that post transistor definition, topside passivation and deposition techniques can significantly impact device degradation characteristics. This work further investigates the choice of local interconnect etch-stop layer and its effect on channel hot-electron degradation. A reduction in channel hot-electron degradation is demonstrated through the use of N2O anneal gate oxide, and using experimental data a possible degradation mechanism, caused by the presence of the etch-stop layer, is identified. A brief review of the compatibility of etch-stop layers with high performance 0.3 micrometer CMOS devices is presented through interface state and hot-electron stress measurements.