A method of making material layers for semiconductor devices by metal organic vapor phase epitaxy includes the steps of wafer preparation, oxide desorption, growth and post growth with an accompanying reduction of a residual sheet charge at the substrate-epitaxy interface. During the oxide desorption step, a substrate is heated to a temperature minimlly necessary to remove oxide from the substrate. In accordance with such method, material layers for a low noise high electron mobility transistor (HEMT) can be grown without a bulk, buffer layer immediately adjacent the substrate. Rather, a super lattice structure is immediately adjacent to and between the substrate and a channel layer.