2014
Volume 14, Number 1/2, pp. 18–21
Chemical passivation of the InAs (100) surface by aqueous sodium sulfide solutions
V.L. Berkovits,1 P.A. Dement’ev,1 T.V. L’vova,1 I.V. Sedova,1 V.P. Ulin,1 G.N. Iluridze,2 A.V. Gigineishvili,2 P.J. Kervalishvili2, * and T.A. Minashvili2
1 A.F. Ioffe Physico-Technical Institute, 194021 St Petersburg, Russia
2 Georgian Technical University, 0175 Tbilisi, Georgia
The effect of a wet chemical treatment in a 1 M aqueous Na2S solution on the chemical composition, photoluminescence intensity and structure of InAs (100) surfaces was studied. We show that the treatment removes surface oxide and forms instead a continuous sulfide chemisorbed surface layer, thus producing an effective surface passivation. The sulfide layer desorbs from the InAs surface upon annealing at 400 °C, uncovering the clean In-rich surface with (4×2) reconstruction. The surface obtained is atomically flat with a high crystalline quality and, can, therefore, be used as a substrate for the epitaxial growth of semiconductor heterostructures. Sulfide-passivated InAs samples demonstrate a remarkable increase of photoluminescence, evidencing surface electronic passivation.
Keywords: atomic force microscopy, Auger electron spectroscopy, indium arsenide, passivation, photoluminescence, sodium sulfide solution, surface structure