화학공학소재연구정보센터
Journal of Crystal Growth, Vol.251, No.1-4, 449-454, 2003
Surfactant enhanced growth of GaNAs and InGaNAs using bismuth
Dilute nitride GaNAs thin films and InGaNAs single quantum wells (QWs) have been grown by molecular beam epitaxy with a concurrent bismuth flux. Bi does not incorporate into the films and acts as a surfactant. Atomic force microscopy images reveal that, at sufficiently high bismuth flux, step flow growth occurs in GaN0.004As0.996 even at substrate temperatures as low as 460degreesC. This results in an order of magnitude decrease in the surface roughness. A similar smoothing effect is obtained when growing GaAs and AlGaAs thin films with bismuth. Furthermore, Bi is found to enhance the incorporation of nitrogen into GaNAs. The peak photo luminescence intensity from an In0.26Ga0.74N0.01As0.989 QW is increased by more than a factor of two with the surfactant. We conclude that Bi reduces the incorporation of defects and/or impurities in the dilute GaNAs based alloys. (C) 2002 Elsevier Science B.V. All rights reserved.