Thermochemical reaction of ZrOx(N-y) interfaces on Ge and Si substrates

Abstract

We have studied the thermochemical characteristics of ZrOx(N-y)/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 ZrOx(N-y)/Ge gate stack to show a better equivalent-oxide-thickness scalability as compared to ZrOx(N-y)/Si gate stack. However, the volatilization of GeOx-contained interfacial layer also caused the formation of small pits and/or holes in the overlying ZrOx(N-y) gate dielectrics, which was expected to cause deterioration in the electrical properties of fabricated high-k/Ge devices. (c) 2006 American Institute of Physics.