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Title: Donor and double-donor transitions of the carbon vacancy related EH{sub 6∕7} deep level in 4H-SiC

Abstract

Using medium- and high-resolution multi-spectra fitting of deep level transient spectroscopy (DLTS), minority carrier transient spectroscopy (MCTS), optical O-DLTS and optical-electrical (OE)-MCTS measurements, we show that the EH{sub 6∕7} deep level in 4H-SiC is composed of two strongly overlapping, two electron emission processes with thermal activation energies of 1.49 eV and 1.58 eV for EH{sub 6} and 1.48 eV and 1.66 eV for EH{sub 7}. The electron emission peaks of EH{sub 7} completely overlap while the emission peaks of EH{sub 6} occur offset at slightly different temperatures in the spectra. OE-MCTS measurements of the hole capture cross section σ{sub p0}(T) in p-type samples reveal a trap-Auger process, whereby hole capture into the defect occupied by two electrons leads to a recombination event and the ejection of the second electron into the conduction band. Values of the hole and electron capture cross sections σ{sub n}(T) and σ{sub p}(T) differ strongly due to the donor like nature of the deep levels and while all σ{sub n}(T) have a negative temperature dependence, the σ{sub p}(T) appear to be temperature independent. Average values at the DLTS measurement temperature (∼600 K) are σ{sub n2+}(T) ≈ 1 × 10{sup −14} cm{sup 2}, σ{sub n+}(T) ≈ 1 × 10{sup −14} cm{sup 2}, and σ{sub p0}(T) ≈ 9 × 10{sup −18} cm{sup 2} for EH{sub 6} and σ{submore » n2+}(T) ≈ 2 × 10{sup −14} cm{sup 2}, σ{sub n+}(T) ≈ 2 × 10{sup −14} cm{sup 2}, σ{sub p0}(T) ≈ 1 × 10{sup −20} cm{sup 2} for EH{sub 7}. Since EH{sub 7} has already been identified as a donor transition of the carbon vacancy, we propose that the EH{sub 6∕7} center in total represents the overlapping first and second donor transitions of the carbon vacancy defects on both inequivalent lattice sites.« less

Authors:
; ; ; ;  [1];  [1];  [2]
  1. Department of Physics, Chemistry and Biology (IFM), Semiconductor Materials Division, Linköping University, 581 83 Linköping (Sweden)
  2. (Iceland)
Publication Date:
OSTI Identifier:
22596823
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 119; Journal Issue: 23; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ACTIVATION ENERGY; CARBON; CARRIERS; CROSS SECTIONS; DEEP LEVEL TRANSIENT SPECTROSCOPY; ELECTRON CAPTURE; ELECTRON EMISSION; HOLES; HYDROGEN 4; RECOMBINATION; SILICON CARBIDES; TEMPERATURE DEPENDENCE; VACANCIES

Citation Formats

Booker, I. D., E-mail: ianbo@ifm.liu.se, Janzén, E., E-mail: erija@ifm.liu.se, Son, N. T., Hassan, J., Stenberg, P., Sveinbjörnsson, E. Ö., E-mail: einars@hi.is, and Science Institute, University of Iceland, IS-107 Reykjavik. Donor and double-donor transitions of the carbon vacancy related EH{sub 6∕7} deep level in 4H-SiC. United States: N. p., 2016. Web. doi:10.1063/1.4954006.
Booker, I. D., E-mail: ianbo@ifm.liu.se, Janzén, E., E-mail: erija@ifm.liu.se, Son, N. T., Hassan, J., Stenberg, P., Sveinbjörnsson, E. Ö., E-mail: einars@hi.is, & Science Institute, University of Iceland, IS-107 Reykjavik. Donor and double-donor transitions of the carbon vacancy related EH{sub 6∕7} deep level in 4H-SiC. United States. doi:10.1063/1.4954006.
Booker, I. D., E-mail: ianbo@ifm.liu.se, Janzén, E., E-mail: erija@ifm.liu.se, Son, N. T., Hassan, J., Stenberg, P., Sveinbjörnsson, E. Ö., E-mail: einars@hi.is, and Science Institute, University of Iceland, IS-107 Reykjavik. 2016. "Donor and double-donor transitions of the carbon vacancy related EH{sub 6∕7} deep level in 4H-SiC". United States. doi:10.1063/1.4954006.
@article{osti_22596823,
title = {Donor and double-donor transitions of the carbon vacancy related EH{sub 6∕7} deep level in 4H-SiC},
author = {Booker, I. D., E-mail: ianbo@ifm.liu.se and Janzén, E., E-mail: erija@ifm.liu.se and Son, N. T. and Hassan, J. and Stenberg, P. and Sveinbjörnsson, E. Ö., E-mail: einars@hi.is and Science Institute, University of Iceland, IS-107 Reykjavik},
abstractNote = {Using medium- and high-resolution multi-spectra fitting of deep level transient spectroscopy (DLTS), minority carrier transient spectroscopy (MCTS), optical O-DLTS and optical-electrical (OE)-MCTS measurements, we show that the EH{sub 6∕7} deep level in 4H-SiC is composed of two strongly overlapping, two electron emission processes with thermal activation energies of 1.49 eV and 1.58 eV for EH{sub 6} and 1.48 eV and 1.66 eV for EH{sub 7}. The electron emission peaks of EH{sub 7} completely overlap while the emission peaks of EH{sub 6} occur offset at slightly different temperatures in the spectra. OE-MCTS measurements of the hole capture cross section σ{sub p0}(T) in p-type samples reveal a trap-Auger process, whereby hole capture into the defect occupied by two electrons leads to a recombination event and the ejection of the second electron into the conduction band. Values of the hole and electron capture cross sections σ{sub n}(T) and σ{sub p}(T) differ strongly due to the donor like nature of the deep levels and while all σ{sub n}(T) have a negative temperature dependence, the σ{sub p}(T) appear to be temperature independent. Average values at the DLTS measurement temperature (∼600 K) are σ{sub n2+}(T) ≈ 1 × 10{sup −14} cm{sup 2}, σ{sub n+}(T) ≈ 1 × 10{sup −14} cm{sup 2}, and σ{sub p0}(T) ≈ 9 × 10{sup −18} cm{sup 2} for EH{sub 6} and σ{sub n2+}(T) ≈ 2 × 10{sup −14} cm{sup 2}, σ{sub n+}(T) ≈ 2 × 10{sup −14} cm{sup 2}, σ{sub p0}(T) ≈ 1 × 10{sup −20} cm{sup 2} for EH{sub 7}. Since EH{sub 7} has already been identified as a donor transition of the carbon vacancy, we propose that the EH{sub 6∕7} center in total represents the overlapping first and second donor transitions of the carbon vacancy defects on both inequivalent lattice sites.},
doi = {10.1063/1.4954006},
journal = {Journal of Applied Physics},
number = 23,
volume = 119,
place = {United States},
year = 2016,
month = 6
}
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  • The effects of hydrostatic pressure on the properties of the deep gold (Au) acceptor level and on the binding energies of shallow donors and acceptors in silicon are presented and discussed. The pressure dependences of the Gibbs free energy, enthalpy, and entropy associated with electron emission from the Au acceptor were determined from measurements of the electron emission rate and electron-capture cross section (sigma/sub n/) as functions of pressure and temperature. The results allow determination of the breathing-mode lattice relaxation accompanying electron emission from this center. The relaxation is found to be relatively large and inward (i.e., contraction). This appearsmore » to be the first quantitative determination of this relaxation for any electronic level in any semiconductor. Other highlights of the results on the Au acceptor are the findings that (i) the energy of this level is pinned to neither the conduction- nor valence-band edges, contrary to earlier belief and (ii) sigma/sub n/, which is known to be temperature independent, is also pressure independent. This latter result is discussed in terms of possible mechanisms for nonradiative electron capture. For the shallow donors and acceptors, the pressure derivatives of the binding energies are over an order of magnitude smaller than those of the energy gap and the Au acceptor, i.e., these levels remain essentially pinned to their corresponding band edges, as expected. These results can be understood in terms of effective-mass theory.« less
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