PROPERTIES OF SILICON PULSE-DOPED INGAP LAYERS GROWN BY LP-MOCVD

Silicon doped In0.49Ga0.51P layers were grown at 560 degrees C and 50 mbar by low pressure metal organic chemical vapour deposition (LP-MOCV D). A delta-doping technique was used for the doping of the InGaP laye rs. The sheet carrier concentration increases linearly with the silane mole fraction in the feed gas. The highest value of the sheet concent ration obtained was 5.9 x 10(12)cm(-2), which corresponds to a 3D-conc entration of 1.5 x 10(19) cm(-3). The width of doping profiles ranges between 3 and 6 nm, indicating low diffusion of silicon in the InGaP. The Hall electron mobility at 300 K was only slightly dependent on the doping level, and it was between 680 and 480 cm(2) V-1 s(-1). The low electron mobility is due to a high concentration of native background accepters originating from growth gases. A strong band-acceptor (e-A( 0)) transition, appearing in the photoluminescence (PL) spectra, confi rms the presence of accepters at a high density. (C) 1997 Elsevier Sci ence S.A.