Comparison of homogeneously grown and temperature-graded InAlAs buffers in the range 400-560 °C: Effects on surface morphology and layer stability

The surface morphology and layer stability of InGaAs/InAlAs/InP heterostructures with their InAlAs buffers grown at temperatures in the range T g = 400-560 °C were studied. Samples with a temperature-graded buffer were compared to those with a homogeneous buffer grown at constant temperature. Results show 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 high electron mobility transistor (HEMT) structures