US 9,812,488 B2
Backside illuminated image sensor and method of manufacturing the same
Tsung-Han Tsai, Miaoli County (TW); Yun-Wei Cheng, Taipei (TW); Chun-Hao Chou, Tainan (TW); Kuo-Cheng Lee, Tainan (TW); Yung-Lung Hsu, Tainan (TW); and Hsin-Chi Chen, Tainan (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD., Hsinchu (TW)
Filed by TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD., Hsinchu (TW)
Filed on Sep. 15, 2015, as Appl. No. 14/854,672.
Claims priority of provisional application 62/163,548, filed on May 19, 2015.
Prior Publication US 2016/0343752 A1, Nov. 24, 2016
Int. Cl. H01L 27/146 (2006.01)
CPC H01L 27/1464 (2013.01) [H01L 27/1463 (2013.01); H01L 27/14614 (2013.01); H01L 27/14638 (2013.01); H01L 27/14689 (2013.01); H01L 27/14621 (2013.01); H01L 27/14627 (2013.01); H01L 27/14643 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An image sensor including a pixel array, wherein the pixel array comprises a plurality of pixels, and wherein each of the plurality of pixels includes:
a semiconductor substrate having a first surface and a second surface opposite to the first surface;
a photosensitive element in the semiconductor substrate;
a gate structure partially over the first surface of the semiconductor substrate; and
a temporary carrier depository in proximity to the first surface of the semiconductor substrate,
wherein the gate structure comprises a plug portion extending from the first surface toward the second surface, a section of the plug portion being laterally coupled to the photosensitive element by means of having a semiconductor substrate separation between the section of the plug portion and the photosensitive element, and
wherein the photosensitive element comprises a doping concentration profile having a doping concentration at a bottom of the photosensitive element greater than a doping concentration at a top of the photosensitive element.