Method of increasing end point detection capability of reactive ion

Abstract

A method of forming a semiconductor device includes forming of layers of polysilicon and dielectric layers in manufacturing a semiconductor device and patterning the layers into devices using phototlithography and etching process steps. End point mode detection is used in the etching process in a way in which the area exposed during etching is increased to enhance the end point detection capacity, by adding a surplus pad area before pad formation. Specifically an EPROM device is formed with a first level of polysilicon above a gate oxide layer patterned into a floating gate electrode of an EPROM device. Then form an ONO layer above the floating gate electrode. Define array protection, grow a second gate oxide layer, deposit a second level of polysilicon, define peripheral gates from the second level of polysilicon, and define an EPROM transistor gate electrode from the second level of polysilicon.