Amorphous silicon-carbon thin films
This study has shown that it is possible to produce nearly stoichiometric films of a-SiC:H with high hydrogen content by rf sputtering in an atmosphere of argon, propane, and hydrogen. The a-SiC films adhere to a variety of substrates and exhibit better thermal stability than a-Si:H films. The index of refraction is 2.8. The optical gap energy of these films is between 2.0 and 2.2 eV. A series of isochronal annealing steps show that optical gap energies decrease, optical absorption edge widths increase, and that the minimum optical density in the low absorption region increases with annealing above 450/sup 0/C. Infrared measurements show large absorptions at 2100, 1000, 750, and 650 cm/sup -1/ corresponding to SiH stretch, CH wagging, SiC stretch, and SiH wagging vibrational modes. The CH/sub n/ stretch mode near 2900 cm/sup -1/ is very small. Isochronal annealing causes a nearly continuous decrease in the integrated intensity of the SiH stretch mode at 2100 cm/sup -1/. The 2100 absorption peak shape may indicate the presence of SiH/sub 2/ in the film. Comparison of the 2100 and 750 absorption peaks show that the Si-C bonds are more heat resistant than the Si-H bonds. Annealing experiments reveal that the decrease in optical gap energy with increasing annealing temperature is probably not due to change in the Si-H bonds. Rather, the decrease is most likely due to changes or breaks in the C-H bonds and possibly the Si-C bonds. NMR results show that the films have high hydrogen concentrations. Also, NMR results and the integrated intensity for the SiH stretch mode give correct order of magnitude determination of the number and concentration of Si-H bonds in the a-SiC:H films.
- Research Organization:
- Ames Lab., IA (USA)
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 5306967
- Report Number(s):
- IS-T-1090; ON: DE84007369
- Resource Relation:
- Other Information: Thesis
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SILICON CARBIDES
INFRARED SPECTRA
OPTICAL PROPERTIES
PRODUCTION
AMORPHOUS STATE
ANNEALING
HYDROGEN
HYDROGENATION
NUCLEAR MAGNETIC RESONANCE
SILANES
SPUTTERING
THIN FILMS
CARBIDES
CARBON COMPOUNDS
CHEMICAL REACTIONS
ELEMENTS
FILMS
HEAT TREATMENTS
HYDRIDES
HYDROGEN COMPOUNDS
MAGNETIC RESONANCE
NONMETALS
PHYSICAL PROPERTIES
RESONANCE
SILICON COMPOUNDS
SPECTRA
360601* - Other Materials- Preparation & Manufacture