Electrical and optical characterization of 4H-SiC diodes for particle detection
2005 (English)In: Journal of Applied Physics, ISSN 0021-8979, Vol. 97, no 10, 103539- p.Article in journal (Refereed) Published
The electronic and optical properties of several (medium to high quality) 4H-SiC epitaxial sensors for particle detection have been studied. The samples are n -doped Schottky diodes with different nitrogen concentrations (6× 1013 cm-3 -5× 1015 cm-3) and thicknesses (20-40 µm). A full electrical and optical characterization has been performed by capacitance versus voltage measurements and near-band-edge low-temperature photoluminescence. The effective doping along the epilayer and the depletion width have been determined and data are consistent with the charge collection efficiency characterization performed with a minimum ionizing ? -source. All the investigated samples exhibit a 100% collection efficiency. In particular, the best samples yield a highly reproducible signal, well separated from the pedestal. Photoluminescence results show a linear relationship between the effective doping and the ratio of nitrogen-bound excitonic emission (Q0) and free excitonic line (I76), in agreement with a previous work on 4H-SiC with a higher doping concentration [I. G. Ivanov, C. Hallin, A. Henry, O. Kordina, and E. Janzn, J. Appl. Phys. 80, 3504 (1996)]. Moreover we show that the dependence of the major spectral features as a function of the penetration depth of the exciting laser beam can quantitatively provide information on substrate contribution to the photoluminescence. In conclusion, we bring evidence that a detailed characterization of SiC-based detectors, by all optical techniques, yields an accurate value for the net doping and gives a qualitative information on the epilayer thickness prior to any electrical wafer tests. © 2005 American Institute of Physics.
Place, publisher, year, edition, pages
2005. Vol. 97, no 10, 103539- p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-45444DOI: 10.1063/1.1906294OAI: oai:DiVA.org:liu-45444DiVA: diva2:266340