We have studied the thermochemical characteristics of ZrO x(Ny)/Ge and Si interfaces by employing postdeposition annealing. We found that Ge oxide species severely desorbed from the inherent interfacial layer, which was speculated to retard the formation of Zr germanate during high-temperature processing. These unique features enable ZrO x(Ny)/Ge gate stack to show a better equivalent-oxide-thickness scalability as compared to ZrOx(N y)/Si gate stack. However, the volatilization of GeO x-contained interfacial layer also caused the formation of small pits and/or holes in the overlying ZrOx(Ny) gate dielectrics, which was expected to cause deterioration in the electrical properties of fabricated high-k/Ge devices.
|Journal||Applied Physics Letters|
|State||Published - 14 Jul 2006|