Nonvolatile floating gate transistor structure

Claim 1

A transistor comprising: a region of semiconductor material; a source formed within said semiconductor material; a drain formed within said semiconductor material; a floating gate formed above at least a portion of the part of said semiconductor material between said source and drain; and means for preventing light from reaching said floating gate, said means for preventing comprising: a control gate, said control gate extending over said floating gate, said source, said drain, and the portion of said semiconductor material surrounding said floating gate, said control gate being opaque, said control gate hindering light from reaching said floating gate and removing electrical charge stored on said floating gate; and an opaque cover formed on said transistor, said opaque cover also preventing light from reaching said floating gate and removing electrical charge stored on said floating gate, said transistor further comprising a first insulation layer for insulating said control gate from said opaque cover, a portion of said opaque cover laterally surrounding said transistor and being in direct contact with said semiconductor material, and wherein said drain extends outwardly beyond the edge of said opaque cover, the portion of said drain at said edge of said opaque cover being separated from said opaque cover by a second insulation layer formed on said drain and a second opaque layer formed between said second insulation layer and said opaque cover, said second opaque layer being formed from the same material as said control gate.