US 12,322,590 B2
Semiconductor device and method
Ching-Yu Chang, Taipei (TW); Jei Ming Chen, Tainan (TW); and Tze-Liang Lee, Hsinchu (TW)
Assigned to Taiwan Semiconductor Manufacturing Co., Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Co., Ltd., Hsinchu (TW)
Filed on Nov. 30, 2023, as Appl. No. 18/525,473.
Application 18/525,473 is a continuation of application No. 17/874,614, filed on Jul. 27, 2022, granted, now 11,854,798.
Application 17/874,614 is a continuation of application No. 16/916,499, filed on Jun. 30, 2020, granted, now 11,482,411, issued on Oct. 25, 2022.
Prior Publication US 2024/0112905 A1, Apr. 4, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H01L 21/02 (2006.01); H01L 21/3065 (2006.01); H01L 21/308 (2006.01); H01L 21/768 (2006.01)
CPC H01L 21/02274 (2013.01) [H01L 21/3065 (2013.01); H01L 21/308 (2013.01); H01L 21/76802 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
forming on a substrate a layer;
forming a patterned layer by patterning the layer to have first trenches extending in a first direction;
conformally depositing a first mask layer over the patterned layer, the first mask layer extending into the first trenches;
depositing a second mask layer on the first mask layer;
patterning the second mask layer to have second trenches extending at least partially through the second mask layer, respective second trenches extending in a second direction and having an aspect ratio in a range of from about 3.5 to about 13 in at least one direction;
filling respective second trenches with fill material;
removing the second mask layer while leaving the fill material in place, the fill material forming respective hard mask structures extending in the second direction within respective first trenches in the first patterned layer;
anisotropically etching the first mask layer to remove horizontal surfaces of the first mask layer while leaving remnants of the first mask layer along sidewalls of the first trenches and under the hard mask structures; and
forming third trenches in the substrate using the patterned layer, the hard mask structures and the remnants of the first mask layer as a hard mask to prevent removal of portions of the substrate underlying the hard mask structures and underlying the remnants of the first mask layer.