Papers by Author: Augustinas Galeckas

Paper TitlePage

Authors: Vytautas Grivickas, Augustinas Galeckas, Paulius Grivickas, Jan Linnros
Authors: John Österman, Anders Hallén, Mikael Jargelius, Uwe Zimmermann, Augustinas Galeckas, Bo Breitholtz
Authors: Augustinas Galeckas, Jan Linnros, Vytautas Grivickas, Ulf Lindefelt, Christer Hallin
Authors: Augustinas Galeckas, Jan Linnros, P. Pirouz
Authors: Augustinas Galeckas, Jan Linnros, Bo Breitholtz, H. Bleichner
Authors: O. Tornblad, Augustinas Galeckas, Jan Linnros, Bo Breitholtz, Ulf Lindefelt
Authors: Augustinas Galeckas, H. K.-Nielsen, Jan Linnros, Anders Hallén, Bengt Gunnar Svensson, P. Pirouz
Abstract: The effects of hydrogen and proton irradiation on stacking fault formation in 4H-SiC are investigated by an optical pump-probe method of imaging spectroscopy. We report optically stimulated nucleation and expansion of stacking faults (SFs) in 0.6 keV 2H+ implanted n-/n+ and p+/n-/n+ structures. The activation enthalpy for recombination enhanced dislocation glide (REDG) in hydrogenated samples (~0.25 eV) is found to be similar to that in a virgin material. Our results indicate that SFs mainly nucleate at the internal n-/n+ interface, beyond reach of hydrogen, thus justifying minor SF passivation effect. No REDG could be initiated optically in 2.5 MeV proton irradiated samples due to radiation defects providing alternative recombination channels to bypass the REDG mechanism. The radiation damage was verified by DLTS, revealing several new levels below EC in the range 0.4-0.80 eV, and by PL, showing the onset of D-center related luminescence band and concurrent increase of the nonradiative recombination rate.
Authors: Augustinas Galeckas, Anders Hallén, Adolf Schöner, Jan Linnros, P. Pirouz
Abstract: We investigate the possibility of controlling formation of stacking faults (SFs) at the interface region by implanting the 4H-SiC substrate with low-energy antimony ions (75 keV Sb+) prior to conventional CVD growth of the homoepitaxial layers. This approach is based on the solidsolution hardening concept, according to which interaction of impurity atoms with dislocations makes the motion of the latter more difficult. Photoluminescence imaging spectroscopy is employed to investigate incorporation of Sb+ implants at the buried interface and also to assess its impact on structural degradation. Spectral results are analyzed considering both the onset of n-type doping and irradiation damage. The latter factor was estimated separately from supplementary measurements of high-energy (2.5 MeV H+) proton-irradiated 4H-SiC epilayers. We compare results of optically stimulated SF formation in virgin and Sb implanted regions and provide a comprehensive picture of the defect evolution, including microscopic details of the imminent nucleation sites.
Showing 1 to 10 of 15 Paper Titles