Growth of highly (111)-oriented, highly coalesced diamond films on platinum (111) surface: A possibility of heteroepitax
- PDF / 120,547 Bytes
- 2 Pages / 612 x 792 pts (letter) Page_size
- 79 Downloads / 232 Views
MATERIALS RESEARCH
Welcome
Comments
Help
Growth of highly (111)-oriented, highly coalesced diamond films on platinum (111) surface: A possibility of heteroepitaxy Yoshihiro Shintani Department of Electric and Electronic Engineering, Faculty of Engineering, The University of Tokushima, 2-1, Minami-josanjima-cho, Tokushima 770, Japan (Received 9 October 1995; accepted 8 August 1996)
A highly (111)-oriented, highly coalesced diamond film was grown on platinum (111) surface by microwave plasma chemical vapor deposition (MPCVD). Scanning electron microscopy and x-ray diffraction analyses revealed that the (111) diamond facets were azimuthally oriented epitaxially with respect to the orientation of the Pt(111) domain underneath, with the neighboring facets of diamond being coalesced with each other. The film was confirmed as diamond using Raman spectroscopy.
This communication reports a discovery of the growth of a highly (111)-oriented, highly coalesced diamond film on platinum (111) surface by microwave plasma chemical vapor deposition (MPCVD). So far, significant numbers of studies have been done about diamond CVD on Pt, but it was only randomly oriented polycrystalline diamond films that have resulted.1–5 By contrast, it was found by the present author that diamond films grown on Pt(111) surface by MPCVD using proper growth conditions have (111) diamond facets that were azimuthally oriented epitaxially with respect to the orientation of the Pt(111) domain underneath, with the neighboring facet of diamond being coalesced with each other, as seen in Fig. 1. In order to prepare Pt with (111) domains, a Pt foil about 0.5 mm thick was thinned by a rolling machine, followed by an overnight thermal annealing in air at about 1500 ±C. It was found that after the thinningannealing process was repeated for several times until the foil thickness became less than about 0.2 mm, the surface of the Pt foil consisted of microstructures of single crystal domains of about 0.1 mm2 , more than 30% of which had (111) surfaces. The (111) orientation of those domains was confirmed by electron channeling pattern (ECP) measurements. Subsequently, the surface of the thinned Pt foil was ultrasonically scratched in ethanol mixed with diamond powder for 10–30 min in order to increase the nucleation density of diamond in CVD. The Pt foil thus treated was cut into pieces of about 1 cm2 and placed in a NIRIM-type (National Institute for Research in Inorganic Materials, Tsukuba, Japan) MPCVD reactor for diamond CVD. The growth conditions were as follows: the source gas was methane diluted to 0.2 –0.3% with hydrogen, the gas flow rate was 100 standard cubic centimeters per minute (sccm), the gas pressure was 60 Torr (8.0 kPa), the input microwave power was 350 –400 W, the substrate temperature, monitored by an optical pyrometer without emissivity correcJ. Mater. Res., Vol. 11, No. 12, Dec 1996
http://journals.cambridge.org
Downloaded: 17 Mar 2015
tion, was 870 –880 ±C, and finally the growth time was 24 –50 h. As a result, a diamond film of a
Data Loading...
