US 12,170,302 B2
Increased optical path for long wavelength light by grating structure
Yun-Wei Cheng, Taipei (TW); Chun-Hao Chou, Tainan (TW); and Kuo-Cheng Lee, Tainan (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsin-Chu (TW)
Filed on Feb. 9, 2023, as Appl. No. 18/166,560.
Application 16/578,296 is a division of application No. 15/938,066, filed on Mar. 28, 2018, granted, now 10,504,952, issued on Dec. 10, 2019.
Application 18/166,560 is a continuation of application No. 17/156,851, filed on Jan. 25, 2021, granted, now 11,581,352.
Application 17/156,851 is a continuation of application No. 16/672,814, filed on Nov. 4, 2019, granted, now 10,930,692, issued on Feb. 23, 2021.
Application 16/672,814 is a continuation of application No. 16/578,296, filed on Sep. 21, 2019, granted, now 10,804,307, issued on Oct. 13, 2020.
Claims priority of provisional application 62/552,114, filed on Aug. 30, 2017.
Prior Publication US 2023/0197751 A1, Jun. 22, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H01L 27/146 (2006.01)
CPC H01L 27/14629 (2013.01) [H01L 27/14621 (2013.01); H01L 27/14627 (2013.01); H01L 27/1463 (2013.01); H01L 27/14636 (2013.01); H01L 27/14645 (2013.01); H01L 27/14649 (2013.01); H01L 27/14685 (2013.01); H01L 27/14687 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An image sensor comprising:
a semiconductor substrate having a first side and a second side, wherein a plurality of photodetectors is arranged in the semiconductor substrate between the first side and the second side; and
a grating structure extending from the second side of the semiconductor substrate into a photodetector of the plurality of photodetectors, wherein the grating structure includes one or more first wall features extending along a first direction with respect to a top view and one or more second wall features extending along a second direction perpendicular to the first direction with respect to the top view; and
wherein the one or more first wall features directly contact a doped region of the photodetector.