Patent ID: 7663179
Filing Date: 2010-02-16
Classification: H01L

Abstract:
1. A semiconductor device comprising a rewritable nonvolatile memory cell including a first field effect transistor for memory, a circuit including a second field effect transistor and a circuit including a third field effect transistor, wherein the first field effect transistor comprises a first gate insulating film formed over a semiconductor substrate, a first gate electrode formed over the first gate insulating film, and first sidewall spacers formed over sidewalls of the first gate electrode, wherein the second field effect transistor comprises a second gate insulating film formed over the semiconductor substrate, a second gate electrode formed over the second gate insulating film, and second sidewall spacers formed over sidewalls of the second gate electrode, wherein the third field effect transistor comprises a third gate insulating film formed over the semiconductor substrate, a third gate electrode formed over the third gate insulating film, and third sidewall spacers formed over sidewalls of the third gate electrode, wherein the third gate insulating film has a thickness larger than the thickness of the second gate insulating film, wherein the third gate electrode has a gate length smaller than the gate length of the first gate electrode and larger than the gate length of the second gate electrode, and wherein the first sidewall spacers and the third sidewall spacers have a width larger than the width of the second sidewall spacers, in the gate length direction, respectively, wherein the first gate insulating film comprises a first insulating film formed over the semiconductor substrate, a charge storage film formed over the first insulating film and a second insulating film formed over the charge storage film, wherein the first gate electrode is formed over the second insulating film, wherein first sidewall spacers comprise a first silicon oxide film formed over the semiconductor substrate and over each of the side walls of the first gate electrode, a first silicon nitride film formed over the first silicon oxide film and a second silicon oxide film formed over the first silicon nitride film, and wherein the first silicon oxide film has a thickness larger than the thickness of the first insulating film, wherein the thickness of the first silicon nitride film is larger than that of the first silicon oxide film, wherein the charge storage film is formed of a insulating film having a discrete trap level, and wherein charges are stored in the discrete trap level.