Patent ID: 8372699

Claim:
A method of forming a semiconductor device, the method comprising: forming a first semiconductor layer over a substrate; forming a first photoresist layer over the first semiconductor layer; using only a first single mask, patterning the first photoresist layer to form a first patterned photoresist layer; using the first patterned photoresist layer, etching the first semiconductor layer to form a select gate; forming a charge storage layer over the select gate and a portion of the substrate; forming a second semiconductor layer over the charge storage layer; forming a second photoresist layer over the second semiconductor layer; using only a second single mask patterning the second photoresist layer to form a second patterned photoresist layer; forming a control gate by anisotropically etching the second semiconductor layer and then subsequently, with the second patterned photoresist layer removed, isotropically etching the second semiconductor layer using etching processes that do not remove the charge storage layer, wherein a portion of the control gate overlaps the select gate, and wherein the method for forming the semiconductor device has only two masking steps; and after anisotropically etching and isotropically etching the second semiconductor layer to form the control gate, removing portions of the charge storage layer that are not covered by the control gate.