Comparison of homogeneously grown and temperature-graded InAlAs buffers inthe range 400-560 degrees C: effects on surface morphology and layer stability

We studied the surface morphology and layer stability of InGaAs/InAlAs/InP heterostructures with their InAlAs buffers grown at temperatures in the ran ge T-g = 400-560 degrees C, We compared samples with a temperature-graded b uffer to those with a homogeneous buffer grown at constant temperature. Our results demonstrate that, although the bulk of the buffer was grown at low or high T-g, the introduction of a few nanometers grown at optimum growth temperature improved the quality of HEMT heterostructures. (C) 1999 Elsevie r Science S.A. All rights reserved.