Patent
1988-07-01
1991-07-23
James, Andrew J.
357 236, 357 2314, 357 30, 357 47, 357 53, 357 54, 357 84, H01L 2968, H01L 2978, H01L 2992, H01L 2714
Patent
active
050347861
ABSTRACT:
A structure for preventing light from reaching and erasing a floating gate comprises a control gate which covers not only the floating gate, but the portion of the semiconductor substrate laterally surrounding the floating gate. In accordance with one novel feature of my invention, a conductive structure also laterally surrounds the floating gate and extends between the semiconductor substrate and the control gate. In one embodiment, the conductive structure is electrically shorted to ground and is constructed from the same layer of material as the floating gate. Of importance, the conductive structure both serves as an additional light blocking structure and also serves as a field plate so that it is not necessary to form a thick field oxide layer surrounding the transistor. Because the conductive structure and the control gate are used as the light blocking structure and the contact metallization layer is not used to form the opaque cover, it is possible to extend contact metallization over the covered floating gate transistor.
REFERENCES:
patent: 3518494 (1970-06-01), James
patent: 3573571 (1971-04-01), Brown et al.
patent: 4258378 (1981-03-01), Wall
patent: 4267558 (1981-05-01), Guterman
patent: 4291326 (1981-09-01), Higuchi et al.
patent: 4302766 (1981-11-01), Guterman et al.
patent: 4317273 (1982-03-01), Guterman et al.
patent: 4376947 (1983-03-01), Chiu et al.
patent: 4376983 (1983-03-01), Tsaur et al.
patent: 4409723 (1983-10-01), Harari
patent: 4519050 (1985-05-01), Folmsbee
patent: 4527259 (1985-07-01), Watanabe
patent: 4536941 (1985-08-01), Kuo et al.
patent: 4581622 (1986-04-01), Takasaki
patent: 4590503 (1986-05-01), Harari et al.
patent: 4758869 (1988-07-01), Eitan et al.
patent: 4805138 (1989-02-01), McElroy et al.
patent: 4825278 (1989-04-01), Hillenius et al.
Folmsbee, "PROM Cell Made with an EPROM Process", International Electron Devices Meeting, 1983, Technical Digest, pp. 574-576.
Spaw et al., "A 128K EPROM with Redundancy" IEEE International Solid-State Circuits Conference Digest of Technical Paper, Feb. 10-12, 1982, pp. 112-113.
James Andrew J.
Kim Daniel Y. J.
Waferscale Integration Inc.
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