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United States Patent 5,886,368
Forbes, et. al. Mar. 23, 1999

Transistor with silicon oxycarbide gate and methods of fabrication and use


A CMOS-compatible FET has a reduced electron affinity polycrystalline or microcrystalline silicon oxycarbide (SiOC) gate that is electrically isolated (floating) or interconnected. The SiOC material composition is selected to establish a desired barrier energy between the SiOC gate and a gate insulator. In a memory application, such as a flash EEPROM, the SiOC composition is selected to establish a lower barrier energy to reduce write and erase voltages and times or accommodate the particular data charge retention time needed for the particular application. In a light detector or imaging application, the SiOC composition is selected to provide sensitivity to the desired wavelength of light. Unlike conventional photodetectors, light is absorbed in the floating gate, thereby ejecting previously stored electrons therefrom. Also unlike conventional photodetectors, the light detector according to the present invention is actually more sensitive to lower energy photons as the semiconductor bandgap is increased.

Inventors: Forbes; Leonard (Corvallis, OR); Geusic; Joseph E. (Berkeley Heights, NJ); Ahn; Kie Y. (Chappaqua, NY).
Assignee: Micron Technology, Inc. (Boise, ID).
Appl. No.: 902,132
Filed: Jul. 29, 1997
Intl. Cl. : H01L 31/0312
Current U.S. Cl.:
Field of Search: 257/76, 77, 315, 316, 323, 364, 411, 412

References Cited | [Referenced By]

U.S. Patent Documents
4,460,670Jul., 1984Ogawa et al. 430/57
4,507,673Mar., 1985Aoyama aet al. 357/23.R
4,657,699Apr., 1987Nair 252/513
4,738,729Apr., 1988Yoshida et al. 136/258
4,893,273Jan., 1990Usami 365/185
5,111,430May, 1992Morie 365/185
5,145,741Sept., 1992Quick 428/402
5,260,593Nov., 1993Lee 257/316
5,293,560Mar., 1994Harari 365/185
5,369,040Nov., 1994Halvis et al. 437/3
5,449,941Sept., 1995Yamazaki et al. 257/411
5,465,249Nov., 1995Cooper et al. 365/149
5,477,485Dec., 1995Bergemont et al. 365/185.24
5,508,543Apr., 1996Hartstein et al. 257/314
5,530,581Jun., 1996Cogan 359/265
5,580,380Dec., 1996Liu et al. 117/86
5,670,790Sept., 1997Katoh et al. 257/14
5,801,401Sept., 1998Forbes 257/77

Foreign Patent Documents
3-222367Oct., 1991JP
6-224431Aug., 1994JP
6-302828Oct., 1994JP
8-255878Oct., 1996JP
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Primary Examiner: Crane; Sara
Attorney, Agent or Firm: Schwegman, Lundberg, Woessner & Kluth, P.A.
40 Claims, 19 Drawing Figures

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