Combined chemical mechanical polishing and reactive ion etching process

A process of planarizing the surface of a semiconductor substrate. The process begins by forming patterned raised and recessed regions on the surface of the semiconductor substrate. A layer of material then is formed over the patterned raised and recessed regions. The layer is subjected to a chemical mechanical planarizing (CMP) process step until all of the raised regions are at least partially removed from the layer. Finally, the surface of the polished substrate is etched with a reactive ion etching (RIE) process.