New Insight Into PBTI Evaluation Method for nMOSFETs With Stacked High-k/IL Gate Dielectric

作者：Lee Sang Kyung^*; Jo Minseok; Sohn Chang Woo; Kang Chang Yong; Lee Jack C; Jeong Yoon Ha; Lee Byoung Hun

来源：IEEE Electron Device Letters, 2012, 33(11): 1517-1519.

DOI：10.1109/LED.2012.2211072

• HfO2
• lifetime
• nMOSFET
• positive bias temperature instability (PBTI)
• trap cluster

In this letter, a strategy to minimize the error in lifetime projections using a positive bias temperature instability (PBTI) test has been proposed. Two distinctly different projection slopes were observed in a plot of time to failure versus oxide electric field. A small slope in the high-field region, which means weaker electric field dependence, led to an underestimation of lifetime. This result was attributed to a filled trap cluster at a specific trap energy level, locally reducing the oxide electric field. Thus, different lifetimes can be projected depending on stress bias. Maintaining a PBTI stress bias range below this trap energy level is recommended for accurate projections.

• 出版日期2012-11