TY - JOUR
T1 - Hydrogenation effects on carrier transport in boron-doped ultrananocrystalline diamond/amorphous carbon films prepared by coaxial arc plasma deposition
AU - Katamune, Yuki
AU - Takeichi, Satoshi
AU - Ohmagari, Shinya
AU - Yoshitake, Tsuyoshi
N1 - Funding Information:
This work was partly supported by the Grant-in-Aid for Japan Society for the Promotion of Science (JSPS) Fellows (13J07294), the Grant-in-Aid for Science Research (24656389), the Advanced Low Carbon Technology Research and Development Program (ALCA), Japan Science and Technology (JST), a research grant from the Mazda Foundation. The first author (Y.K.) was supported by a research fellowship from the Japan Society for the Promotion of Science for Young Scientists.
Publisher Copyright:
© 2015 American Vacuum Society.
PY - 2015
Y1 - 2015
N2 - Boron-doped ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/ a-C:H) films were deposited by coaxial arc plasma deposition with a boron-blended graphite target at a base pressure of <103 Pa and at hydrogen pressures of 53.3 Pa. The hydrogenation effects on the electrical properties of the films were investigated in terms of chemical bonding. Hydrogen-scattering spectrometry showed that the maximum hydrogen content was 35 at. % for the film produced at 53.3-Pa hydrogen pressure. The Fourier-transform infrared spectra showed strong absorptions by sp3 C-H bonds, which were specific to the UNCD/a-C:H, and can be attributed to hydrogen atoms terminating the dangling bonds at ultrananocrystalline diamond grain boundaries. Temperature-dependence of the electrical conductivity showed that the films changed from semimetallic to semiconducting with increasing hydrogen pressure, i.e., with enhanced hydrogenation, probably due to hydrogenation suppressing the formation of graphitic bonds, which are a source of carriers. Carrier transport in semiconducting hydrogenated films can be explained by a variable-range hopping model. The rectifying action of heterojunctions comprising the hydrogenated films and n-type Si substrates implies carrier transport in tunneling.
AB - Boron-doped ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/ a-C:H) films were deposited by coaxial arc plasma deposition with a boron-blended graphite target at a base pressure of <103 Pa and at hydrogen pressures of 53.3 Pa. The hydrogenation effects on the electrical properties of the films were investigated in terms of chemical bonding. Hydrogen-scattering spectrometry showed that the maximum hydrogen content was 35 at. % for the film produced at 53.3-Pa hydrogen pressure. The Fourier-transform infrared spectra showed strong absorptions by sp3 C-H bonds, which were specific to the UNCD/a-C:H, and can be attributed to hydrogen atoms terminating the dangling bonds at ultrananocrystalline diamond grain boundaries. Temperature-dependence of the electrical conductivity showed that the films changed from semimetallic to semiconducting with increasing hydrogen pressure, i.e., with enhanced hydrogenation, probably due to hydrogenation suppressing the formation of graphitic bonds, which are a source of carriers. Carrier transport in semiconducting hydrogenated films can be explained by a variable-range hopping model. The rectifying action of heterojunctions comprising the hydrogenated films and n-type Si substrates implies carrier transport in tunneling.
UR - http://www.scopus.com/inward/record.url?scp=85058217042&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85058217042&partnerID=8YFLogxK
U2 - 10.1116/1.4931062
DO - 10.1116/1.4931062
M3 - Article
AN - SCOPUS:85058217042
SN - 0734-2101
VL - 33
JO - Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
JF - Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
IS - 6
M1 - 061514
ER -