Boiko V.M.,Karpov Institute of Physical Chemistry |
Brudnyi V.N.,Tomsk State University |
Verevkin S.S.,Karpov Institute of Physical Chemistry |
Ermakov V.S.,Karpov Institute of Physical Chemistry |
And 3 more authors.
Semiconductors | Year: 2014
The effect of irradiation with full-spectrum reactor neutrons and predominantly fast reactor neutrons (up to a fluence of 8 × 1018 cm-2) on the electrical properties of epitaxial p-GaN(Mg) films at different initial doping levels (in the range of hole concentrations p = 1017-1019 cm-3) is analyzed. It is found that neutron irradiation induces an increase in the resistivity of the initial material to 1010 Ω cm at 300 K. It is shown that, at high neutron fluences, the resistivity of the material decreases because of the hopping conduction of charge carriers over radiation defect states. The study of isochronous annealing at 100-1000°C reveals stages of donor-defect (100-300°C, 500-700°C, 750-850°C) and acceptor-defect (300-500°C, 650-800°C) annealing in the neutron-irradiated p-GaN(Mg) samples. © 2014 Pleiades Publishing, Ltd.
Prostomolotov A.I.,Russian Academy of Sciences |
Verezub N.A.,Russian Academy of Sciences |
Mezhennii M.V.,Joint Stock Company Giredmet |
Reznik V.Y.,Joint Stock Company Giredmet
Journal of Crystal Growth | Year: 2011
In this article, we consider a number of questions related to the thermal optimization of 200 mm diameter Si Czochralski (CZ) single-crystal growth process using the new Redmet-90M puller and the rapid thermal annealing (RTA) of Si wafers cut from single crystals. The article includes results of the CZ numerical modeling of heat transfer, which takes into account the special thermal shield assemblies (with and without water cooling). The influences of various crucible rotation rates on the distribution of the azimuthal velocity of the melt and on the liquidsolid interface were also investigated. Differences in axial temperature profiles of the growing crystal were analyzed depending on whether the thermal shield was used with or without its water-cooling system and depending on the various crucible rotation rates. A numerical diffusionrecombination model of intrinsic point defects (vacancies and interstitial Si atoms), which takes into account the vacancy cluster formation, was applied for RTA optimization. Vacancy concentration, density and sizes of vacancy clusters were calculated along the thickness of a wafer. An experimental study on the defect structure in the annealed Si wafers was carried out by the light microscopy and the transmission electron microscopy. The type, density and morphology of defects in the thickness of a wafer were also analyzed. The experimental distribution of total defect density in the thickness of a wafer was compared with the calculated vacancy cluster density. © 2010 Elsevier B.V. All rights reserved.