Browse by author
Lookup NU author(s): Dr Rajat Mahapatra, Professor Nick Wright
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
Open-volume (vacancy-type) point defects have been observed in ∼80-nm -thick titanium dioxide films grown on silicon dioxide 4H silicon carbide substrates as stacks with high dielectric constant for power device applications, using variable-energy positron annihilation spectroscopy. The concentration of vacancies decreases as the titanium dioxide growth temperature is increased in the range from 700 to 1000 °C, whereas grain boundaries form in the polycrystalline material at the highest growth temperatures. It is proposed that the optimal electrical performance for films grown at 800 °C reflects a balance between decreasing vacancy concentration and increasing grain boundary formation. The concentration of vacancies at the silicon dioxidesilicon carbide interface appears to saturate after 2.5 h oxidation at 1150 °C. A supplementary result suggests that the quality of the 10-μm -thick deposited silicon carbide epilayer is compromised at depths of about 2 μm and beyond, possibly by the migration of impurities andor other defects from the standard-grade highly doped 4H silicon carbide wafer beneath the epilayer during oxidation. © 2007 American Institute of Physics.
Author(s): Coleman PG, Burrows CP, Mahapatra R, Wright NG
Publication type: Article
Publication status: Published
Journal: Journal of Applied Physics
Year: 2007
Volume: 102
Issue: 1
ISSN (print): 0021-8979
ISSN (electronic): 1089-7550
Publisher: American Institute of Physics
URL: http://dx.doi.org/10.1063/1.2752129
DOI: 10.1063/1.2752129
Altmetrics provided by Altmetric
