W. Vonmunch et S. Wiebach, PRODUCTION OF BETA-SIC BUFFER LAYERS FOR CVD DIAMOND THIN-FILMS BY ION-IMPLANTATION, DIAMOND AND RELATED MATERIALS, 3(4-6), 1994, pp. 500-505
The difference between the lattice constants of silicon and diamond is
approximately 52%. Therefore a heteroepitaxial buffer layer on the si
licon substrate should improve the crystallization behaviour of diamon
d obtained by chemical vapour deposition (CVD). Beta-SiC has a lattice
constant which is just between these two materials. A 100 keV ion imp
lanter has been used to attempt the generation of an SiC buffer layer.
C-12 ions were implanted into a silicon target at different energies
(40 and 100 keV), ion doses (between 3.3 x 10(18) and 1.0 x 10(18) cm-
2) and target temperatures (liquid-nitrogen temperature to 900-degrees
-C). Some samples were annealed at 1200-degrees-C in an N2 atmosphere.
[100]-oriented silicon as well as [111]-oriented silicon was used as
target materials. A wet-etching process in a KOH solution was employed
to expose the implanted beta-SiC layer. CVD diamond films were deposi
ted on substrates which were pre-treated by these methods. Subsequent
to the implantation and annealing processes the specimens were investi
gated by means of X-ray diffraction, Raman spectroscopy and Rutherford
backscattering spectroscopy. The investigation demonstrate that, alth
ough defective, endotaxial beta-SiC layers can be formed by ion implan
tation of C-12 in silicon substrates.