TiN/HfO[sub 2]/SiO[sub 2]/Si Gate Stack Breakdown: Contribution of HfO[sub 2] and Interfacial SiO[sub 2] Layer

By studying systematically the breakdown mechanisms of HfO 2 and interfacial SiO 2 separately in this work, we have demonstrated that defect generation in the interfacial SiO 2 layer seems to be the leading breakdown mechanism in the metal/high-κ/interfacial layer/Si gate stack. The individual breakdown characteristics of HfO 2 , without any interfacial layer using a metal–insulator–metal capacitor, and an in situ steam-grown SiO 2 metal–oxide–semiconductor capacitor with identical thicknesses and growth conditions, were compared with the gate stack characteristics. The breakdown behavior and stress-induced leakage current measurements suggest that charge trapping and stress-induced trap formation in the interfacial layer continues to be the soft spot for gate stack breakdown.