US 12,322,651 B2
Etching to reduce line wiggling
Kuan-Wei Huang, Taoyuan (TW); Cheng-Li Fan, New Taipei (TW); and Yu-Yu Chen, Hsinchu (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Co., Ltd., Hsinchu (TW)
Filed on Jan. 27, 2022, as Appl. No. 17/586,412.
Application 17/586,412 is a continuation of application No. 16/679,940, filed on Nov. 11, 2019, granted, now 11,244,858.
Application 16/679,940 is a continuation of application No. 15/726,035, filed on Oct. 5, 2017, granted, now 10,475,700, issued on Nov. 12, 2019.
Claims priority of provisional application 62/552,490, filed on Aug. 31, 2017.
Prior Publication US 2022/0148918 A1, May 12, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H01L 21/786 (2006.01); H01L 21/033 (2006.01); H01L 21/311 (2006.01); H01L 21/768 (2006.01); H01L 23/522 (2006.01); H01L 23/532 (2006.01); H01L 23/535 (2006.01)
CPC H01L 21/76877 (2013.01) [H01L 21/0332 (2013.01); H01L 21/0337 (2013.01); H01L 21/31138 (2013.01); H01L 21/31144 (2013.01); H01L 21/76829 (2013.01); H01L 21/76841 (2013.01); H01L 23/5226 (2013.01); H01L 23/53228 (2013.01); H01L 23/53257 (2013.01); H01L 23/535 (2013.01); H01L 21/31111 (2013.01); H01L 21/31116 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
depositing a first mask over a first patterning layer, the first mask having a first thickness as deposited, wherein the first mask is comprised of one or more sub-masks;
forming a first set of openings extending to a first depth in the first mask, the first set of openings having respective bottoms defined by a surface of the first mask material;
thinning the first mask to a second thickness, less than the first thickness, after the step of forming a first set of openings in the first mask and before a step of forming a set of extended openings in the first mask, wherein at least a portion of each sub-mask of the one or more sub-masks remains after the step of thinning the first mask;
after thinning the first mask, forming the set of extended openings in the first mask by etching the surface of the first mask material, the set of extended openings extending from the first depth to a second depth greater than the first depth;
after forming the set of extended openings in the first mask, forming a second set of openings in the first patterning layer by extending the set of extended openings into the first patterning layer, the second set of openings being defined by respective opening sidewalls of the first patterning layer;
widening the second set of openings at a rate greater than widening the first set of extended openings, while at least a portion of the first mask is over the first patterning layer;
using the first patterning layer in a patterning process to pattern an underlying layer; and
removing the first mask.