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Identification of a Donor State of Substitutional Cadmium in Silicon
Author(s) -
Näser A.,
Gehlhoff W.,
Overhof H.,
Yankov R.A.
Publication year - 1998
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/(sici)1521-3951(199812)210:2<753::aid-pssb753>3.0.co;2-h
Subject(s) - silicon , electron paramagnetic resonance , doping , annealing (glass) , acceptor , dopant , cadmium , ground state , density functional theory , singlet state , shallow donor , materials science , spectral line , chemistry , atomic physics , condensed matter physics , molecular physics , crystallography , computational chemistry , nuclear magnetic resonance , physics , excited state , metallurgy , astronomy
The structural and electronic properties of cadmium in p‐type silicon were studied by means of EPR. Cd was diffused in one set of samples whereas in a second set we used high energy implantations in the MeV range for doping, followed by a high temperature annealing step at 1200 °C. The angular variations of the corresponding spectra show cubic symmetry and can be explained with an S = 3/2 orbital singlet ground state. From comparison of the EPR results obtained from samples with different shallow p‐dopants (B, Al, Ga, In) and doping levels it can be concluded, that the spectra arise from the Cd + donor state with an energy level above the In acceptor level. These experimental findings were compared with theoretical predictions of electronic structure calculations based on the Local Density Approximation of the Density Functional Theory using the LMTO‐ASA scheme. The comparison shows that the donor state must be due to substitutional Cd.