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

Abstract

An alternative surface passivation process for high- k Gemetal-oxide-semiconductor(MOS) device has been studied. The surface Si H 4 annealing was implemented prior to Hf O 2 deposition. X-ray photoelectron spectroscopy analysis results show that the Si H 4 surface passivation can greatly prevent the formation of unstable germanium oxide at the surface and suppress the Ge out-diffusion after the Hf O 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 Ta N ∕ Hf O 2 ∕ Ge MOS capacitors with the Si H 4 surface treatment.