Effects of hydrogen annealing on heteroepitaxial-Ge layers on Si: Surface roughness and electrical quality

Ammar Nayfeh, Chi On Chui, Krishna C. Saraswat, Takao Yonehara

Research output: Contribution to conferencePaperpeer-review

1 Scopus citations

Abstract

We have studied the effect of hydrogen annealing on the surface roughness of Germanium (Ge) layers grown by CVD on silicon using atomic force microscopy (AFM) and cross-sectional High Resolution Scanning Electron Microscopy (HR-SEM). Our results indicate a strong reduction of roughness that approaches 90 percent at 825°C. The smoother Ge surface allowed for the fabrication metal-oxide-semiconductor (MOS) capacitors using germanium oxynitride (GeO xN y) as the gate dielectric. Electrical quality was studied using high frequency capacitance-voltage characteristic of epi-Ge showing negligible hysteresis. We discuss the results in terms of Ge-H cluster formation, which lowers the diffusion barrier, allowing for higher diffusivity and surface mobility. The temperature dependence shows tapering off for temperatures exceeding 825°C, indicating a barrier reduction of ∼70 meV.

Original languageBritish English
Pages1189-1192
Number of pages4
StatePublished - 2004
EventSiGe: Materials, Processing, and Devices - Proceedings of the First Symposium - Honolulu, HI, United States
Duration: 3 Oct 20048 Oct 2004

Conference

ConferenceSiGe: Materials, Processing, and Devices - Proceedings of the First Symposium
Country/TerritoryUnited States
CityHonolulu, HI
Period3/10/048/10/04

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