US 11,782,411 B2
System and method for mitigating overlay distortion patterns caused by a wafer bonding tool
Franz Zach, Los Gatos, CA (US); Mark D. Smith, San Jose, CA (US); and Roel Gronheid, Leuven (BE)
Assigned to KLA Corporation, Milpitas, CA (US)
Filed by KLA Corporation, Milpitas, CA (US)
Filed on Jan. 31, 2022, as Appl. No. 17/589,516.
Claims priority of provisional application 63/226,635, filed on Jul. 28, 2021.
Prior Publication US 2023/0035201 A1, Feb. 2, 2023
Int. Cl. G05B 19/18 (2006.01); H01L 21/67 (2006.01)
CPC G05B 19/188 (2013.01) [H01L 21/67121 (2013.01); H01L 21/67288 (2013.01); G05B 2219/45031 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A system comprising:
a wafer shape metrology sub-system configured to perform one or more shape measurements on a pair of pre-bonding wafers and a corresponding post-bonding pair of wafers; and
a controller communicatively coupled to the wafer shape metrology sub-system, the controller including one or more processors configured to execute a set of program instructions stored in a memory, the set of program instructions configured to cause the one or more processors to:
receive a set of measured bonding distortions;
apply a bonder control model to the measured bonding distortions, wherein the bonder control model is generated by bonding wafer pairs with different settings of one or more adjustors of a bonder tool to generate a set of overlay distortion patterns; measuring at least some of the overlay distortion patterns of the set of overlay distortion patterns using the wafer shape metrology sub-system; extracting actuator-induced changes as the difference in the overlay distortion patterns relative to a set of control adjustor positions; and generating a set of stored orthogonal wafer signatures based on the actuator-induced changes;
determine whether a set of predicted overlay distortion signatures associated with the set of measured bonding distortions are outside tolerance limits by comparing the set of predicted overlay distortion signatures to the stored orthogonal wafer signatures; and
provide one or more feedback adjustments to the bonder tool to adjust one or more bonder tool adjustors when the set of predicted overlay distortion signatures are outside tolerance limits.