| US 7,612,404 B2 | ||
| Semiconductor device | ||
| Akihito Yamamoto, Naka-gun (Japan); Masayuki Tanaka, Yokohama (Japan); Katsuyuki Sekine, Yokohama (Japan); Daisuke Nishida, Yokohama (Japan); Ryota Fujisuka, Yokohama (Japan); Katsuaki Natori, Yokohama (Japan); Hirokazu Ishida, Yokohama (Japan); and Yoshio Ozawa, Yokohama (Japan) | ||
| Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan) | ||
| Filed on Apr. 13, 2007, as Appl. No. 11/783,933. | ||
| Claims priority of application No. 2006-112190 (JP), filed on Apr. 14, 2006. | ||
| Prior Publication US 2007/0241388 A1, Oct. 18, 2007 | ||
| Int. Cl. H01L 29/788 (2006.01) | ||
| U.S. Cl. 257—321 [257/316; 257/325; 257/E29.3] | 20 Claims |
| 1. A semiconductor device comprising:
a semiconductor substrate;
an isolation insulating film provided on the semiconductor substrate;
a plurality of nonvolatile memory cells provided on the semiconductor substrate,
each of the plurality of nonvolatile memory cells comprising:
a tunnel insulating film provided on the semiconductor substrate,
a floating gate electrode provided on the tunnel insulating film,
a control gate electrode provided above the floating gate electrode,
an interelectrode insulating film provided between the control gate electrode and the floating gate electrode and including
a first insulating film and a second insulating film provided on the first insulating film and having higher permittivity
than the first insulating film, the interelectrode insulating film being provided on a side wall of the floating gate electrode
in a cross-section view of a channel width direction of the nonvolatile memory cell, thickness of the interelectrode insulating
film increasing from an upper portion of the side wall toward a lower portion of the side wall, thickness of the second insulating
film on an upper corner of the floating gate electrode being thicker than thickness of the second insulating film on the other
portions of the side wall of the floating gate electrode in the cross-section view of the channel width direction.
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