Diamond nucleation kinetic at low pressure─the disscussion of residual seeds and defects on substrate surface.
碩士 === 國立成功大學 === 地球科學系 === 81 === A gas mixture of CH/Hwas used to synthesize diamond by hot filament chemical vapor deposition technique.Both chemical (residual seeds) and mechanical imperfections were incorporated onto the substrate surf...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Others |
| Language: | zh-TW |
| Published: |
1993
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| Online Access: | http://ndltd.ncl.edu.tw/handle/94570172001476788285 |
| Summary: | 碩士 === 國立成功大學 === 地球科學系 === 81 === A gas mixture of CH/Hwas used to synthesize diamond by hot
filament chemical vapor deposition technique.Both chemical
(residual seeds) and mechanical imperfections were incorporated
onto the substrate surface inthe present study to compare their
effects on diamond nu--cleation. The characteristic features of
the syhtnetic materials were analyzed with XRD ，SEM ，FTIR ，
RAMAN spectroscopy techniques. XRD was used to analyze crystal
structure ；The morphology and size and nuclei density of the
microcrystallites were calculated based on SEM observation ；
The interface between diamond and substrate was examined with
FTIR ；RAMAN technique was employed to distinguish the
impurities in diamond. The growth parameters varied included
substrate temperature、substrate materials 、and substrate
surface pretreatments. The substrate temperatures were varied
from 650℃ to 950℃. Substrate materials included silicon(100)
wafer and graphite. Substrate surface pretreatments，involved
(1) overlaid tungsten wire on graphite substrate、sintering of
graphite fibers onto graphite substrate in different
orientations、local coating of carbon and goldfilms on silicon
substrate；(2) modifications of surface defects such as
scratching of silicon surface with diff- -erent abrasive
materials、grif size and scratching orientation. The present
results show that different of residuals(seeds) have varied
effects in enhancement on nucleation density of diamonds. Among
them，carbon residuals appear to possess the highest effect in
promoting nucleationdensity of diamond in this study. The
present study also suggests that the nature and the
characteristic features of the residual seeds on yhe substrate
surface are more significant in enhancing the diamond
nucleation.
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