The effect of boron doping and gamma irradiation on the structure and properties of microwave chemical vapor deposited boron-doped diamond films
- 1 April 2009
- journal article
- research article
- Published by Springer Science and Business Media LLC in Journal of Materials Research
- Vol. 24 (4), 1498-1512
- https://doi.org/10.1557/jmr.2009.0170
Abstract
We investigated the effects of gamma irradiation doses of 50, 100, and 103 kGy on boron-doped diamond (BDD) thin films synthesized using microwave plasma-assisted chemical vapor deposition with varying boron concentrations of [B]/[C]gas = 100, 1000, 2000, and 4000 ppm. The diamond thin films were characterized prior to and post-irradiation and the influence was assessed in terms of morphology, structure, and physical properties using scanning electron microscopy, atomic force microscopy, x-ray diffraction, vibrational spectroscopy (Raman and IR), x-ray photoelectron spectroscopy, and electrical measurement techniques. The results clearly showed that the response of gamma irradiation on BDD films was distinctive compared to those of undoped diamond films with changes in electronic behavior from metallic (>1019 to 1020 cm–3) to semiconducting (≤1019 cm–3), especially in the case of heavily boron-doped diamond films demonstrated by micro-Raman spectroscopy and electrical property characteristics. In fact, this modification in electrical property behavior induced by “gamma conditioning” can be effectively used to fine control boron doping in chemically vapor deposited diamond much needed for various electronic devices. The “gamma conditioning” refers to material processing by radiation which helps to passivate electrically active boron and defects with hydrogen migration thus fine tunes the boron acceptor concentration albeit that this is difficult to achieve during BDD film deposition. In addition, the results also indicate that almost all of the BDD films studied hereby tend to reach a state of damage saturation when submitted to gamma irradiation of 103 kGy. We discuss our novel findings in terms of the interplay of boron-hydrogen in diamond with possible multiple scenarios: (i) the generation of point/Frenkel defects due to Compton scattered electrons, (ii) the formation of a nonmetallic boron-rich borocarbide (e.g., B13C2) phase, (iii) the passivation of electrically active acceptor (B) sites due to the invariable presence of H in the grains and at the grain boundaries, (iv) the desorption of H from the diamond surface, and (v) the “priming or pumping” effect, which improves the electronic properties by compensating for the shallow boron acceptors to produce semiconducting/insulating material, verified by the cold neutron depth profiling technique.Keywords
This publication has 40 references indexed in Scilit:
- Demonstration of a radiation resistant, high efficiency SiC betavoltaicApplied Physics Letters, 2006
- Nanosecond semiconductor diodes for pulsed power switchingPhysics-Uspekhi, 2005
- Modeling of diamond radiation detectorsJournal of Applied Physics, 2004
- Electron field emission properties of gamma irradiated microcrystalline diamond and nanocrystalline carbon thin filmsJournal of Applied Physics, 2002
- Analysis of the Fano in diamondDiamond and Related Materials, 2001
- Loss of electrical conductivity in boron-doped diamond due to ion-induced damageApplied Physics Letters, 1997
- The migration of interstitial H in diamond and its pairing with substitutional B and N: Molecular orbital theoryJournal of Materials Research, 1994
- Mass assay and uniformity tests of boron targets by neutron beam methodsNuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1993
- Optical absorption and luminescence in diamondReports on Progress in Physics, 1979
- Elements of X-Ray DiffractionAmerican Journal of Physics, 1957