Abstract: Epitaxial growth of semiconductor materials is carried out by introducing two or more reaction gases along with their carrier gas into a reaction chamber via one or more concentric pipe inlets and a plurality of separately distributed injection ports with a gas distribution system. The reaction gas can be injected into the reaction chamber either continuously or in pulse mode, wherein reaction gases are mixed together or injected alternately into the reaction chamber. The semiconductor materials are deposited on the substrates which are located on the rotating heated susceptor within the reaction chamber.