公开(公告)号：US20190079410A1

公开(公告)日：2019-03-14

申请号：US16124492

申请日：2018-09-07

Applicant: ASML Netherlands B.V.

Inventor： Niels Geypen

IPC: G03F7/20 ,  G03F9/00

CPC classification number: G03F7/70633 ,  G03F7/70491 ,  G03F7/705 ,  G03F7/70508 ,  G03F7/70616 ,  G03F9/7092

Abstract: A method of aligning a pair of complementary diffraction patterns having a first complementary diffraction pattern and a second complementary diffraction pattern, the pair of complementary diffraction patterns obtained from performance of a metrology process on a structure formed by a lithographic process. The method includes performing at least a fine alignment stage to align the pair of complementary diffraction patterns. The alignment stage includes: interpolating measured values of the first complementary diffraction pattern over at least a portion of a detector area; and minimizing a residual between measured values in the second complementary diffraction pattern and corresponding interpolated values from the interpolation of the first complementary diffraction pattern, by one or both of translation and rotation of the second complementary diffraction pattern.

公开(公告)号：US10126662B2

公开(公告)日：2018-11-13

申请号：US15912036

申请日：2018-03-05

Applicant: ASML Netherlands B.V.

Inventor： Scott Anderson Middlebrooks ,  Niels Geypen ,  Hendrik Jan Hidde Smilde ,  Alexander Straaijer ,  Maurits Van Der Schaar ,  Markus Gerardus Martinus Maria Van Kraaij

IPC: G03F7/20

Abstract: Disclosed is a method of measuring a parameter of a lithographic process, and associated inspection apparatus. The method comprises measuring at least two target structures on a substrate using a plurality of different illumination conditions, the target structures having deliberate overlay biases; to obtain for each target structure an asymmetry measurement representing an overall asymmetry that includes contributions due to (i) the deliberate overlay biases, (ii) an overlay error during forming of the target structure and (iii) any feature asymmetry. A regression analysis is performed on the asymmetry measurement data by fitting a linear regression model to a planar representation of asymmetry measurements for one target structure against asymmetry measurements for another target structure, the linear regression model not necessarily being fitted through an origin of the planar representation. The overlay error can then be determined from a gradient described by the linear regression model.