We discuss the growth of InxGa1-xP quantum dots on nominally (1 0 0)-oriented GaP substrates by low-pressure metal organic vapor phase epitaxy. Parameters like the growth temperature, thickness of the InGaP layer, strain, via the indium composition of InxGa1-xP, and the post-growth ripening time have been varied to study their effect on the growth of self-assembled InGaP quantum dots in Stranski-Krastanow mode. Under optimized conditions quantum dots with lateral dimension similar to50nm and height similar to5nm and a density >10(10) cm(2) have been achieved. Surface photovoltage spectroscopy is shown to be a convenient and sensitive technique to monitor the various stages in the growth of quantum dot structures. (C) 2002 Elsevier Science B.V. All rights reserved.