Charge trapping and breakdown mechanism in HfAIO/TaN gate stack analyzed using carrier separation

Abstract

Charge trapping and breakdown.:mechanism in p- and n-channel MOSFETs with an HfA1(x)O(y) and TaN metal electrode are investigated. Using carrier separation measurement technique, it is possible to clearly distinguish two different breakdown mechanisms: a high-K bulk initiated and an interfacial layer initiated breakdown. A model of charge trapping at different spatial locations in HfAlx O-y with a TaN gate structure is proposed to explain the polarity dependence of charge trapping characteristics and breakdown mechanisms.