Atomic layer deposition of insulating nitride interfacial layers for germanium metal oxide semiconductor field effect transistors with high-κ oxide/tungsten nitride gate stacks

Atomic layer deposition (ALD) was used to deposit passivating interfacial nitride layers between Ge and high-kappa oxides. High-kappa oxides on Ge surfaces passivated by ultrathin (1-2 nm) ALD Hf3N4 or AlN layers exhibited well-behaved C-V characteristics with an equivalent oxide thickness as low as 0.8 nm, no significant flatband voltage shifts, and midgap density of interface states values of 2x10(12) cm(-1) eV(-1). Functional n-channel and p-channel Ge field effect transistors with nitride interlayer/high-kappa oxide/metal gate stacks are demonstrated. (c) 2007 American Institute of Physics.