A burner module for delivering a flow of chemical reactants to a combustion site of a chemical vapor deposition process includes a plurality of substantially planar layers. The substantially planar layers are arranged in a generally parallel and fixed relationship and define an inlet, an outlet and a passage fluidly connecting the inlet and outlet. At least one of the layers is a distribution layer having a plurality of apertures therethrough and fluidly communicating with the passage. The plurality of apertures collectively define a non-uniform pattern arranged and configured to improve the uniformity of a flow out through the outlet. Burner adapter and assembly embodiments are also included.