ELEMENT INCORPORATION IN GAINASP FOR UNIFORM LARGE-AREA MOMBE

In this study we investigated the material incorporation efficiencies in GaInAsP and InAsP layers grown on InP substrates for large area met alorganic molecular-beam epitaxy (MOMBE). We found an optimum growth t emperature for the quaternary material (lambda(G) = 1.55 mu m) around 500-510 degrees C, since in this range the lattice matching shows a te mperature coefficient of about 80-120 ppm only. The P incorporation ef ficiency is improved with increasing growth temperatures (480-520 degr ees C). We found for InAsP and GaInAsP (lambda(G) = 1.05 mu m) a stron g reduction of the P incorporation efficiency with increasing V/III ra tio, which is accompanied by a reduced P content in the layer. Additio nally with this reduced P, the Ga incorporation efficiency for the qua ternary material is improved. Using the same V/III and As/P ratio for the InAsP and GaInAsP material, a higher P content in the InAsP layers is achieved. The results were used as calibration data for the develo pment of a novel type of wafer holder with improved temperature unifor mity. For GaInAsP single layers (lambda G = 1.55 mu m) a standard devi ation in emission wavelength of /Delta lambda/ < 1.5 nm was achieved. From the results for all material compositions a temperature distribut ion with Delta T < 1 degrees C can be inferred across a 2 '' wafer. (C ) 1998 Elsevier Science B.V. All rights reserved.