Method and apparatus for estimating model parameters of and controlling a lithographic apparatus by measuring a substrate property and using a polynomial model

Patent metadata

Field	Value
Publication number	US-8947642-B2
Application number	US-201113010402-A
Country	US
Kind code	B2
Filing date	Jan 20, 2011
Priority date	Feb 17, 2010
Publication date	Feb 3, 2015
Grant date	Feb 3, 2015

Abstract

System and methods estimate model parameters of a lithographic apparatus and control lithographic processing by a lithographic apparatus. An exposure is performed using a lithographic apparatus across a wafer. A set of predetermined wafer measurement locations is obtained. Discrete orthonormal polynomials are generated using the predetermined substrate measurement locations. The overlay errors arising from the exposure are measured at the predetermined locations to obtain overlay measurements. The estimated model parameters of the lithographic apparatus are calculated from the overlay measurements by using the discrete orthogonal polynomials as a basis function to model the overlay across the wafer. Finally, the estimated model parameters are used to control the lithographic apparatus in order to provide corrected overlay across the wafer.

First claim

What is claimed is:

1. A method comprising:
performing a lithographic process using a lithographic apparatus across a substrate;
using predetermined substrate measurement locations to generate discrete orthogonal polynomials;
measuring a substrate property arising from the lithographic process at locations of the substrate corresponding to the predetermined measurement locations to obtain substrate property measurements;
calculating estimated model parameters of the lithogra…

Assignees

• Middlebrooks Scott Anderson
• Asml Netherlands Bv

Inventors

• Middlebrooks Scott Anderson

Classifications

• G03F7/70633 Primary

  Physics · mapped topic

• G03F7/70616

  Physics · mapped topic

• G03F7/705

  Physics · mapped topic