Near IR Refractive Index for GaInN Heavily Doped with Silicon

G. Cywińskia, R. Kudrawiecb, W. Rzodkiewiczc, M. Kryśkoa, E. Litwin Staszewska a, J. Misiewiczb and C. Skierbiszewskia a Institute of High Pressure Physics, Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland b Institute of Physics, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland c Institute of Electron Technology, al. Lotników 32/46, 02-668 Warsaw, Poland

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The authors report on growth and results of infrared measurements of GaInN heavily doped with silicon. The lattice matched to GaN epitaxial layer of Ga0.998In0.002N:Si has been grown in plasma assisted molecular beam epitaxy in the metal rich conditions. The room temperature Hall concentration and mobility of electrons are 2× 1020 cm-3 and 67 cm2/(Vs), respectively. The refractive index has been determined by variable angle spectroscopic ellipsometry. The refractive index exhibited a significant reduction of its value (from 2.25 to 2 at 1.55 μm) at near IR range where are the main interests of potential applications for nitride based intersubband devices. Reported here values of refractive indices at 1.55 and 1.3 μm are appropriate for fabrication of cladding layers with the required contrast to GaN for intersubband devices. The observed drop of refractive index is attributed to the carrier induced plasma edge effect, which has been directly observed in reflectance spectrum.

DOI: 10.12693/APhysPolA.116.936 PACS numbers: 61.72.uj, 78.66.Fd, 81.15.Hi, 68.55.-a, 78.20.-e