NBT导致的深亚微米PMOS器件退化与物理机理

研究了深亚微米PMOS器件在负偏压温度(negative bias temperature, NBT) 应力前后的电流电压特性随应力时间的退化，重点分析了NBT应力对PMOS器件阈值电压漂移的影响，通过实验证明了在栅氧化层和衬底界面附近的电化学反应和栅氧化层内与氢相关的元素的扩散，是PMOS器件中NBT效应产生的主要原因.指出NBT导致的PMOS器件退化依赖于反应机理和扩散机理两种机理的平衡. 关键词： 深亚微米PMOS器件 负偏压温度不稳定性 界面态 氧化层固定正电荷

Degradation and physical mechanism of NBT in deep submicron PMOSFET's

This paper investigates the dependence of current and voltage characterizations on stress time in deep submicron PMOSFET's before and after negative bias temperature (NBT) stress, we mainly focus on the threshold voltage shift under NBT stress. It is experimentally demonstrated that the electrochemical reactions at the interface between gate oxide and substrate and the diffusion of hydrogen related species in the oxide are the major causes of the NBT in PMOSFET's. PMOSFET degradation caused by NBT depends on the balance of reaction limited and diffusion limited mechanisms.