| US 7,554,158 B2 | ||
| Semiconductor device having analog and digital circuits | ||
| Ryota Yamamoto, Kanagawa (Japan); and Kuniko Kikuta, Kanagawa (Japan) | ||
| Assigned to NEC Electronics Corporation, Kanagawa (Japan) | ||
| Filed on Jan. 25, 2006, as Appl. No. 11/338,641. | ||
| Claims priority of application No. 2005-040499 (JP), filed on Feb. 17, 2005. | ||
| Prior Publication US 2006/0180871 A1, Aug. 17, 2006 | ||
| Int. Cl. H01L 29/76 (2006.01) | ||
| U.S. Cl. 257—357 [257/355; 257/356; 257/E21.632; 257/E27.064] | 11 Claims |
| 1. A semiconductor device comprising:
a semiconductor substrate of a first conductivity type;
a digital circuit part and an analog circuit part provided on said semiconductor substrate, wherein at least one of the digital
circuit part and the analog circuit part include a plurality of circuit elements;
a plurality of wells of said first conductivity type which correlate to the plurality of circuit elements formed in either
said analog circuit part or said digital circuit part; and
a first deep well of a second conductivity type, which is an opposite conductivity type to said first conductivity type, wherein
the first deep well isolates less then all of the plurality of circuit elements of at least one of the digital circuit part
and the analog circuit part from said semiconductor substrate.
|