Snapback应力对90nm nMOSFET栅氧化层完整性的影响

基于测试对snapback应力引起的栅氧化层损伤特性和损伤位置进行了研究．研究发现应力期间产生的损伤引起器件特性随应力时间以近似幂指数的关系退化．应力产生的氧化层陷阱将会引起应力引起的泄漏电流增加，击穿电荷减少，也会造成关态漏泄漏电流的退化．栅氧化层损伤不仅在漏区一侧产生，而且也会在源区一侧产生．热空穴产生的三代电子在指向衬底的电场作用下向Si-SiO2界面移动，这解释了源区一侧栅氧化层损伤的产生原因．

Effect of Snapback Stress on Gate Oxide Integrity of nMOSFET in 90nm Technology

By measurement,we investigate the characteristics and location of gate oxide damage induced by snapback stress.The damage incurred during stress causes device degradation that follows an approximate power law with stress time.Oxide traps generated by stress will cause the increase of stress-induced leakage current and the decrease of Qbd (charge to breakdown),and it may also cause the degradation of off-state drain leakage current.Stress-induced gate oxide damage is located not only in the drain side but also in the source side.The tertiary electrons generated by hot holes move toward Si-SiO2 interface under the electrical field toward the substrate,which explains the source side gate oxide damage.