High-resolution X-ray diffraction. Hall effect and secondary ion mass spectrometry measurements (SIMS) were used to study the effect of carbon doping on the lattice constant of GaSb. A linear increase in tensile strain as a function of carbon concentration was observed in the range from 1 x 10(19) to 1 x 10(20) cm The observed strains are consistent with carbon incorporating as a simple substitutional acceptor up to at least 1 x 10(20) cm(-3), SIMS measurements show that the total carbon concentration is linearly proportional to the CCl4 source flows. Whereas the hydrogen concentration increases super-linearly. Nevertheless. the ratio of hydrogen to carbon is no greater than 9% of the maximum incorporated carbon concentration. (C) 2002 Elsevier Science B.V. All rights reserved.