Quantum wells of lnGaAs clad by lnAlAs were grown on AlGaAsSb buffer layers by molecular beam epitaxy. The buffer layer lattice parameters were near 6.0 angstrom. yielding tensile strains up to 2% in the lnGaAs and lnAlAs. Room-temperature electron mobilities of 9000-11,000 cm(2)/V s were achieved. Field-effect transistors (FETs) were fabricated and exhibited good DC and RF characteristics. Previous work demonstrated compressively-strained GaSb quantum wells on similar buffer layers with high hole mobilities and good transistor performance. Hence, a single buffer layer of AlGaAsSb should be suitable for complementary circuits comprised of n-channel FETs based on the mature InGaAs/InAlAs technology and p-channel FETs based on high-mobility antimonides. Published by Elsevier B.V.