A multiple gate field effect transistor and a planar field effect transistor formed in the same substrate each have a top planar surface underneath each corresponding gate that are co-planar with one another and also co-planar with a top surface of a shallow trench isolation region located therebetween. The relatively older planar FET fabrication technology has added to it the relatively newer MUGFET fabrication technology without disruption to the planar fabrication technology and with relatively little added cost.