SI AND C DELTA-DOPING OF GAAS GROWN BY METAL-ORGANIC VAPOR-PHASE EPITAXY FOR FABRICATION OF NIPI DOPING SUPERLATTICES

The growth conditions for Si and C delta-doped nipi doping superlattic es in GaAs have been optimised at the growth temperature of 630 degree s C. We found that the Si delta-doping concentration can be significan tly changed by delta-doping time over the range of 10(12)-10(13) cm(-2 ) at the optimised gas flow velocity. The similar range of the free ho le density in C delta-doped GaAs has also been obtained simply by vary ing the TMAl flow rate during the delta-doping step. The full compensa tion of free electron and hole density in the Si and C delta-doped nip is can be achieved by choosing proper Si delta-doping time and TMAl fl ow rate. Growth of one Si and C delta-doped nipi in GaAs was demonstra ted. Apart from the well-known effect of photo-excitation intensity on the effective band gap energy, the time-resolved photoluminescence re veals that the photoluminescence peak wavelength significantly increas es in the relaxation process of the photo-excited nipi doping superlat tice. (C) 1998 Elsevier Science S.A. All rights reserved.