Annealing effects on the bonding structures, optical and mechanical properties for radio frequency reactive sputtered germanium carbide films
| Autor: | Jiecai Han, Jiaqi. Q. Zhu, Chaoquan Hu, Weitao. T. Zheng |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Materials science
Hydrogen Annealing (metallurgy) Metallurgy Analytical chemistry General Physics and Astronomy chemistry.chemical_element Germanium Surfaces and Interfaces General Chemistry Condensed Matter Physics Surfaces Coatings and Films Carbide chemistry Sputtering Radio frequency Thin film Refractive index |
| Zdroj: | Applied Surface Science. 255:3552-3557 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/j.apsusc.2008.08.115 |
| Popis: | The effects of thermal annealing in vacuum on the bonding structures, optical and mechanical properties for germanium carbide (Ge 1− x C x ) thin films, deposited by radio frequency (RF) reactive sputtering of pure Ge(1 1 1) target in a CH 4 /Ar mixture discharge, are investigated. We find that there are no significant changes in the bonding structure of the films annealed below 300 °C. The fraction of Ge–H bonds for the film annealed at temperatures ( T a ) above 300 °C decreases, whereas that of C–H bonds show a decrease only when T a exceeds 400 °C. The out-diffusion of hydrogen promotes the formation of Ge–C bonds at T a above 400 °C and thus leads to a substantial increase in the compressive stress and hardness for the film. The refractive indices and optical gaps for Ge 1− x C x films are almost constant against T a , which can be ascribed to the unchanged ratios of Ge/C and sp 2 -C/sp 3 -C concentrations. Furthermore, we also find that the excellent optical transmission for an antireflection Ge 1− x C x double-layer film on ZnS substrate is still maintained after annealing at 700 °C. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect