A method to improve the planarity of a semiconductor wafer and an assembly made from the method. In a preferred embodiment of the method, a compressive PECVD oxide layer such as SiO2 having a predetermined thickness or pattern is deposited on the second surface of a semiconductor wafer having an undesirable warp or bow. The thickness or pattern of the deposited oxide layer is determined by the measured warp or bow of the semiconductor wafer. The compressive oxide layer induces an offsetting compressive force on the second surface of the semiconductor wafer to reduce the warp and bow across the major surface of the semiconductor wafer.