MOLECULAR-BEAM EPITAXIAL-GROWTH OF HIGH-QUALITY INP LAYERS FROM SOLIDPHOSPHORUS USING A VALVED PHOSPHORUS CRACKER CELL

We report the molecular beam epitaxial (MBE) growth of epitaxial InP u sing a valved phosphorus cracker cell at a range of cracking-zone temp eratures (T-cr = 875-950 degrees C), V/III flux ratios (V/III = 1.2-9. 3) and substrate temperatures ( T-s = 360-500 degrees C). The as-grown epitaxial InP on an InP (100) substrate is found to be n-type from Ha ll measurements. The background electron concentration and mobility ex hibit a pronounced dependence on the cracking-zone temperature, V/III flux ratio and substrate temperature. Using a T-cr of 850 degrees C, t he highest 77 K electron mobility of 40 900 cm(2) (V s)(-1) is achieve d at a V/III ratio of 2.3 and a T-s of 440 degrees C. The correspondin g background electron concentration is 1.74 x 10(15) cm(-3). The photo luminescence (PL) spectra show two prominent peaks at 1.384 and 1.415 eV, with the intensity of the low-energy peak becoming stronger at hig her cracking-zone temperatures. The lowest PL FWHM achieved at 5 K is 5.2 meV. Within the range of substrate temperatures investigated, the effect on the crystalline quality determined from X-ray diffracton (XR D) measurements is not significant. (C) 1998 Elsevier Science S.A. All rights reserved.