	US 7,492,048 B2
	CMOS sensors having charge pushing regions
James William Adkisson, Jericho, Vt. (US); Jeffrey Peter Gambino, Westford, Vt. (US); Mark David Jaffe, Shelburne, Vt. (US); Jeffrey Bowman Johnson, Essex Junction, Vt. (US); Jerome Brett Lasky, Essex Junction, Vt. (US); and Richard John Rassel, Colchester, Vt. (US)
Assigned to International Business Machines Corporation, Armonk, N.Y. (US)
Filed on Jan. 10, 2006, as Appl. No. 11/275,497.
Prior Publication US 2007/0158711 A1, Jul. 12, 2007
Int. Cl. H01L 31/062 (2006.01)

U.S. Cl. 257—790 [257/233]

20 Claims

1. A semiconductor structure, comprising:

(a) a photo diode that includes a first semiconductor region and a second semiconductor region,

wherein the first semiconductor region is doped with a first doping polarity,

wherein the second semiconductor region is doped with a second doping polarity, and

wherein the first and second doping polarities are opposite;

(b) a transfer gate that comprises (i) a first extension region, (ii) a second extension region, and (iii) a floating diffusion region,

wherein the first extension region is in direct physical contact with the photo diode, and

wherein the second extension region is in direct physical contact with the floating diffusion region; and

wherein the charge pushing region overlaps the first semiconductor region,

wherein the charge pushing region does not overlap the floating diffusion region, and

wherein the charge pushing region comprises a transparent and electrically conducting material.