US 12,142,519 B2
Etch stop detection structure and etch stop detection method
Runshun Wang, Singapore (SG); Mengkai Zhu, Singapore (SG); Zhuona Ma, Singapore (SG); and Hua-Kuo Lee, Singapore (SG)
Assigned to United Microelectronics Corp., Hsinchu (TW)
Filed by United Microelectronics Corp., Hsinchu (TW)
Filed on May 19, 2022, as Appl. No. 17/748,047.
Claims priority of application No. 202210431449.8 (CN), filed on Apr. 22, 2022.
Prior Publication US 2023/0343639 A1, Oct. 26, 2023
Int. Cl. H01L 21/768 (2006.01); H01L 21/66 (2006.01); H01L 23/522 (2006.01); H01L 23/532 (2006.01)
CPC H01L 21/7682 (2013.01) [H01L 21/76829 (2013.01); H01L 22/30 (2013.01); H01L 23/53295 (2013.01); H01L 22/26 (2013.01); H01L 23/5226 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An etch stop detection structure, comprising:
a substrate comprising a device region and a detection region;
a first dielectric layer located on the substrate;
a first stop layer located on the first dielectric layer; and
a second dielectric layer located on the first stop layer, wherein
there is a first air gap in the first dielectric layer and the first stop layer in the device region,
there is a trench in the second dielectric layer in the detection region, and
the trench exposes the first stop layer.