Improved reliability characteristics of Ge MOS devices by capping Hf or Zr on interfacial layer

Abstract Ultralow equivalent oxide thickness and excellent reliability characteristics in Ge MOS devices with ZrO 2 gate dielectrics are achieved by capping Hf or Zr on interfacial layer. Device with a Hf-cap layer demonstrates the lowest interface trap density and stress-induced leakage current. On the other hand, device with a Zr-cap layer exhibits the lowest hysteresis effects and stress-induced voltage shifts. The HfGeO x IL of high quality and ZrGeO x IL with few oxide traps are promising to improve reliability characteristics in Ge MOS devices.