Fitting of optical model with diffraction effects to measured spectrum

Patent metadata

Field	Value
Publication number	US-9011202-B2
Application number	US-201213456035-A
Country	US
Kind code	B2
Filing date	Apr 25, 2012
Priority date	Apr 25, 2012
Publication date	Apr 21, 2015
Grant date	Apr 21, 2015

Abstract

A method of controlling a polishing operation includes obtaining a sequence over time of measured spectra with an in-situ optical monitoring system during polishing. For each measured spectrum from the sequence an optical model is fit. The optical model includes dimensions of a repeating structure and the fitting includes calculating a output spectrum using diffraction effects of the repeating structure, and parameters of the optical model include an endpoint parameter and a parameter of the repeating structure. The fitting generates the sequence of fitted endpoint parameter values, and at least one of a polishing endpoint or an adjustment of a pressure to the substrate is determined from the sequence of fitted endpoint parameter values.

First claim

What is claimed is:

1. A method of controlling a polishing operation, comprising:
polishing a first layer of a substrate;
during polishing, obtaining a sequence over time of measured spectra with an in-situ optical monitoring system;
for each measured spectrum from the sequence of measured spectra, fitting an optical model to the measured spectrum, the fitting including finding parameters that provide a minimum difference between an output spectrum of the optical model and the…

Assignees

• David Jeffrey Drue
• Applied Materials Inc

Inventors

• David Jeffrey Drue

Classifications

• B24B49/12 Primary

  Operations & Transport · mapped topic

• B24B37/013

  Operations & Transport · mapped topic

• H10P52/00 Primary

  Electricity · mapped topic