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Title: Electrical and optical characterization of 4H-SiC diodes for particle detection

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 (6x10{sup 13} cm{sup -3}-5x10{sup 15} cm{sup -3}) and thicknesses (20-40 {mu}m). 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 {beta}-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 (Q{sub 0}) and free excitonic line (I{sub 76}), 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. Janzen, 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 themore » 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.« less
Authors:
; ; ; ; ; ;  [1] ;  [2] ;  [3]
  1. Department of Physics, University of Florence, Via Sansone 1, I-50019 Sesto Fiorentino (Italy)
  2. (INFN), University of Florence, Via di Santa Marta 3, I-50139 Florence (Italy)
  3. (Italy)
Publication Date:
OSTI Identifier:
20709652
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 97; Journal Issue: 10; Other Information: DOI: 10.1063/1.1906294; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CAPACITANCE; CHARGE COLLECTION; CHARGED PARTICLE DETECTION; DOPED MATERIALS; ELECTRIC POTENTIAL; ELECTRONIC STRUCTURE; EPITAXY; LAYERS; NITROGEN; OPTICAL PROPERTIES; PENETRATION DEPTH; PHOTOLUMINESCENCE; SCHOTTKY BARRIER DIODES; SEMICONDUCTOR MATERIALS; SIGNALS; SILICON CARBIDES; SUBSTRATES