US 11,720,031 B2
Overlay design for electron beam and scatterometry overlay measurements
Inna Steely-Tarshish, Yokneam Ilit (IL); Stefan Eyring, Weilburg (DE); Mark Ghinovker, Yoqneam Ilit (IL); Yoel Feler, Haifa (IL); Eitan Hajaj, Ashqelon (IL); Ulrich Pohlmann, Jena (DE); Nadav Gutman, Zichron Ya'aqov (IL); Chris Steely, Yokneam Ilit (IL); Raviv Yohanan, Qiryat Motzkin (IL); and Ira Naot, Milpitas, CA (US)
Assigned to KLA Corporation, Milpitas, CA (US)
Filed by KLA Corporation, Milpitas, CA (US)
Filed on Sep. 28, 2021, as Appl. No. 17/487,725.
Claims priority of provisional application 63/215,551, filed on Jun. 28, 2021.
Prior Publication US 2022/0413394 A1, Dec. 29, 2022
Int. Cl. G03F 7/00 (2006.01); G01N 21/47 (2006.01); G01N 21/95 (2006.01); G03F 7/20 (2006.01)
CPC G03F 7/70633 (2013.01) [G01N 21/4785 (2013.01); G01N 21/4788 (2013.01); G01N 21/9501 (2013.01); G03F 7/70625 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A target comprising:
a first periodic structure formed on a first layer of a semiconductor device, wherein each of a plurality of gratings in the first periodic structure has a first width along a first axis and a first height along a second axis, wherein the first periodic structure has a first pitch;
a second periodic structure formed on a second layer of the semiconductor device, wherein each of a plurality of gratings in the second periodic structure has a second width along the first axis and a second height along the second axis, wherein the second width is narrower than the first width, wherein the second periodic structure has a second pitch less than the first pitch, and wherein the gratings of the first periodic structure are positioned to overlap with the gratings of the second periodic structure, wherein the second periodic structure extends beyond the first periodic structure along the first axis, and wherein the first periodic structure and the second periodic structure are in a first array;
a second array of the first periodic structure and a second of the second periodic structure, wherein the second periodic structure in the second array extends beyond the first periodic structure in a direction along the second axis from that of the first array; and
a third array of the first periodic structure and a third and fourth array of the second periodic structure, wherein the first height is longer than the second height, and wherein the gratings of the first periodic structure in the third array extend over the third and fourth arrays of the second periodic structure along the second axis;
wherein the first periodic structure and the second periodic structure provide electron beam overlay measurements and scatterometry overlay measurements.