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

Autor:	Krishna C. Saraswat, Takao Yonehara, Ammar Nayfeh, Chi On Chui
Rok vydání:	2004
Předmět:	Surface diffusion Materials science Physics and Astronomy (miscellaneous) Diffusion barrier Silicon business.industry Annealing (metallurgy) Gate dielectric Analytical chemistry chemistry.chemical_element Germanium Surface finish chemistry Surface roughness Optoelectronics business
Zdroj:	Applied Physics Letters. 85:2815-2817
ISSN:	1077-3118 0003-6951
DOI:	10.1063/1.1802381
Popis:	We have studied the effect of hydrogen annealing on the surface roughness of germanium (Ge) layers grown by chemical vapor deposition on silicon using atomic force microscopy and cross-sectional high resolution scanning electron microscopy (HR-SEM). Our results indicate a strong reduction of roughness that approaches 90% at 825°C. The smoother Ge surface allowed for the fabrication of metal-oxide-semiconductor capacitors using germanium oxynitride (GeOxNy) 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 800°C, indicating a barrier reduction of ∼92meV.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::f8b795ea19f503bcc2de7624c3e54566 https://doi.org/10.1063/1.1802381 Zobrazit plný text záznamu