Effect of InSb buffer layer in MIS structures based on InP

Indium phosphide (InP) is a promising semiconductor used as a basic substra te for micro and optoelectronic devices. However, its use to form component s on III-V substrates has provided some technical problems (Bideux L et al. Surf Interface Anal 1993;20:803-7; Hollinger G. J Appl Phys 1990;67:4173). Also, the InP surface must be treated and well passivated before the depos ition of the insulator. We show here that the InSb layer can reduce the pho sphorus atoms migration. In the Al2O3:InSb/InP structure, the electrical C( V) characteristics plotted at 1 MHz give, in the depletion region, a more m ushed slope of the curves. The obtained results show clearly the reduction of the defects and consequently, the state density has been decreased by 30 % when compared to the InP protected by an InSb buffer layer to non-treated surfaces. The interfacial state density N-SS is found to be 6 x 10(11) eV( -1) cm(-2). (C) 2001 Elsevier Science Ltd. All rights reserved.