| US 7,468,546 B2 | ||
| Semiconductor device with a noise prevention structure | ||
| Sheng-Yow Chen, Taichung (Taiwan); and Dichi Tsai, Cingshuei Township, Taichung County (Taiwan) | ||
| Assigned to Airoha Technology Corp., Hsinchu (Taiwan) | ||
| Filed on Aug. 25, 2005, as Appl. No. 11/211,187. | ||
| Claims priority of application No. 93125487 A (TW), filed on Aug. 26, 2004. | ||
| Prior Publication US 2006/0046405 A1, Mar. 02, 2006 | ||
| Int. Cl. H01L 23/58 (2006.01); H01L 23/62 (2006.01) | ||
| U.S. Cl. 257—665 [257/781; 257/506; 257/459] | 6 Claims |
| 1. A semiconductor device, comprising:
a substrate of a first semiconductor type comprising a pad region, the pad region comprising an outer ring-shaped doping region
of the first semiconductor type, a central doping region of a second semiconductor type, and a first well of the first semiconductor
type interposed therebetween;
a pad overlying the pad region, wherein the central doping region is electrically connected to the pad;
a dielectric layer at least between the substrate and pad; and
a noise prevention structure in the substrate, on at least one side of the pad region,
wherein the noise prevention structure is further formed substantially across the pad region,
wherein the noise prevention structure comprises a second well, and
wherein the second well of the second semiconductor type is located between the first well and the substrate and isolates
the first well from the substrate.
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