Improved Ge Surface Passivation with Ultrathin $ hbox{SiO}_{X}$ Enabling High-Mobility Surface Channel pMOSFETs Featuring a HfSiO/WN Gate Stack Academic Article uri icon


  • To realize high-mobility surface channel pMOSFETs on Ge, a 1.6-nm-thick SiOx passivation layer between the bulk Ge substrate and HfSiO gate dielectric was introduced. This approach provides a simple alternative to epitaxial Si deposition followed by selective oxidation and leads to one of the highest peak hole mobilities reported for unstrained surface channel pMOSFETs on Ge: 332cm2 · V-1 · s-1 at 0.05 MV/cm - a 2× enhancement over the universal Si/SiO2 mobility. The devices show well-behaved output and transfer characteristics, an equivalent oxide thickness of 1.85 nm and an ION/IOFF ratio of 3 × 103 without detectable fast transient charging. The high hole mobility of these devices is attributed to adequate passivation of the Ge surface. © 2007 IEEE.

author list (cited authors)

  • Joshi, S., Krug, C., Heh, D., Na, H. J., Harris, H. R., Oh, J. W., ... Banerjee, S. K.

citation count

  • 30

publication date

  • April 2007