| US 7,531,407 B2 | ||
| Semiconductor integrated circuit devices having high-Q wafer backside inductors and methods of fabricating same | ||
| Lawrence Clevenger, LaGrangeville, N.Y. (US); Timothy Joseph Dalton, Ridgefield, Conn. (US); Louis Hsu, Fishkill, N.Y. (US); Carl Radens, LaGrangeville, N.Y. (US); Vidhya Ramachandran, Ossining, N.Y. (US); Keith Kwong Hon Wong, Wappingers Falls, N.Y. (US); and Chih-Chao Yang, Poughkeepsie, N.Y. (US) | ||
| Assigned to International Business Machines Corporation, Armonk, N.Y. (US) | ||
| Filed on Jul. 18, 2006, as Appl. No. 11/488,242. | ||
| Prior Publication US 2008/0020488 A1, Jan. 24, 2008 | ||
| Int. Cl. H01L 21/8234 (2006.01) | ||
| U.S. Cl. 438—238 [438/381; 257/E21.022] | 11 Claims |
| 1. A method of forming a semiconductor device, comprising:
forming an integrated circuit on a frontside of a semiconductor substrate;
forming an integrated inductor within a backside insulating layer on a backside of the semiconductor substrate;
forming an interconnection structure through a buried insulating layer interposed between the frontside and backside of the
semiconductor substrate, which connects the integrated inductor to the integrated circuit;
forming a ground plane within the backside insulating layer on the backside of the semiconductor substrate,
wherein forming the integrated inductor structure comprises:
filling a first plurality of via holes etched in a the backside insulating layer to form backside contact plugs;
filling a trench etched in the backside insulating layer to form an inductor coil, wherein the backside contact plugs form
part of the interconnection structure for connecting the inductor coil to the frontside integrated circuit;
filling a second plurality of via holes in the backside insulating layer to form backside dummy contact plugs to support the
integrated inductor, wherein the backside dummy contact plugs each have one end embedded in the backside of the semiconductor
substrate and do not form part of the interconnection structure for connecting the inductor coil to the frontside integrated
circuit; and
forming an air gap surrounding the integrated inductor by removing insulation material from the backside insulating layer.
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