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Electrical characterization of 4H‐SiC Schottky diodes with RuWO x Schottky contacts before and after irradiation by fast electrons
Author(s) -
Benkovska Jana,
Stuchlikova Lubica,
Buc Dalibor,
Čaplovic Lubomir
Publication year - 2012
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201127559
Subject(s) - schottky diode , irradiation , saturation current , equivalent series resistance , schottky barrier , materials science , analytical chemistry (journal) , diode , deep level transient spectroscopy , reverse leakage current , electron , capacitance , activation energy , saturation (graph theory) , optoelectronics , silicon , chemistry , voltage , electrical engineering , physics , electrode , organic chemistry , chromatography , quantum mechanics , nuclear physics , engineering , mathematics , combinatorics
The impact of radiation damage on the device performance of 4H‐SiC Schottky barrier diodes (SBDs) with RuWO x Schottky contacts, which were irradiated at room temperature with 9 MeV electrons (absorbed dose of 50 Gy), is studied by current–voltage ( I – V ) and capacitance–voltage ( C – V ) methods measured in the temperature range of 85–400 K. We have observed the radiation‐induced decrease of the Schottky barrier height (SBH) from original Φ b = 1.13–1.06 eV, increase of the ideality factor from n = 1.14 to 1.39 and the noticeable increase of the saturation current from I S = 7.29 to 77.31 pA and the series resistance from R S = 2.9 to 7.9 Ω calculated from I – V measurements at T = 300 K. As a result of electron irradiation deep energy levels originated in the structure and caused the increase of serial resistance and leakage current. The DLTS results have shown several deep energy levels, e.g ., E C – 0.637 eV pointing to radiation‐induced Z 1/2 structural defects in SiC. No degradation is observed from the measured C – V curves. The experimental value of the effective Richardson constant A * = 50.68 A/cm 2 /K 2 for the irradiated sample was calculated from the modified Richardson plot.