Alternative surface passivation on germanium for metal-oxide-semiconductor applications with high-k gate dielectric

Abstract

An alternative surface passivation process for high-k Ge metal-oxide-semiconductor (MOS) device has been studied. The surface SiH 4 annealing was implemented prior to HfO 2 deposition. X-ray photoelectron spectroscopy analysis results show that the SiH 4 surface passivation can greatly prevent the formation of unstable germanium oxide at the surface and suppress the Ge out-diffusion after the HfO 2 deposition. The electrical measurement shows that an equivalent oxide thickness of 13.5 Å and a leakage current of 1.16 × 10 -5 A/cm 2 at 1 V gate bias was achieved for TaN/HfO 2/Ge MOS capacitors with the SiH 4 surface treatment. © 2004 American Institute of Physics.