Method and apparatus for angular-resolved spectroscopic lithography characterization

Patent metadata

Field	Value
Publication number	US-10955353-B2
Application number	US-201916270155-A
Country	US
Kind code	B2
Filing date	Feb 7, 2019
Priority date	Aug 16, 2004
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

An apparatus and method to determine a property of a substrate by measuring, in the pupil plane of a high numerical aperture lens, an angle-resolved spectrum as a result of radiation being reflected off the substrate. The property may be angle and wavelength dependent and may include the intensity of TM- and TE-polarized radiation and their relative phase difference.

First claim

The invention claimed is:

1. A method, comprising:
placing a wavelength multiplexer between a radiation source and a substrate;
placing a wavelength demultiplexer between the substrate and a detector located in a pupil plane of a high numerical aperture lens;
directing a radiation beam from the radiation source toward the substrate;
detecting, using the detector, an angle-resolved spectrum of the radiation beam reflected from a surface of the substrate; and
measuring asymmetries between intensities of corresponding diffraction orders in the reflected angle-resolved spectrum to measure a property of the substrate.

2. The method of claim 1 , wherein the measuring comprises measuring at least one of:
an intensity of a transverse magnetic and a transverse electric polarized light, and
a phase difference between the transverse magnetic and the transverse electric polarized light.

3. The method of claim 1 , further comprising:
coupling off a portion of the radiation beam emitted from the radiation source for a separate measurement.

4. A method, comprising:
placing a knife edge in one of opposite halves of an intermediate object plane associated with a lens;
directing, using the lens, a radiation beam from a radiation source toward a pattern formed on a substrate; and
measuring asymmetries between intensities of corresponding diffraction orders in an angle-resolved spectrum of a radiation beam diffracted from the pattern, at a plurality of angles and a plurality of wavelengths substantially simultaneously to measure a property of the substrate.

5. The method of claim 4 , wherein the measuring asymmetries comprises measuring at least one of:
an intensity of a transverse magnetic and a transverse electric polarized light, and
a phase difference between the transverse magnetic and the transverse electric polarized light.

6. The method of claim 4 , further comprising:
coupling off a portion of the radiation beam emitted from the radiation source for a separate measurement.

7. A method, comprising:
placing a wavelength multiplexer between a radiation source and a substrate;
placing a wavelength demultiplexer between the substrate and a detector located in a pupil plane of a high numerical aperture lens;
placing a knife edge in one of opposite halves of an intermediate object plane associated with the high numerical aperture lens;
directing, using the high numerical aperture lens, a radiation beam from the radiation source toward the substrate; and
measuring, using the detector, an asymmetry in an angle-resolved spectrum of a radiation beam reflected from a surface of the substrate, at a plurality of angles and a plurality of wavelengths substantially simultaneously to measure a property of the substrate.

Assignees

• Asml Netherlands Bv

Inventors

• Den Boef Arie Jeffrey
• Bleeker Arno Jan
• Van Dommelen Youri Johannes Laurentius Maria
• Dusa Mircea
• Kiers Antoine Gaston Marie
• Luehrmann Paul Frank
• Pellemans Henricus Petrus Maria
• Van Der Schaar Maurits
• Grouwstra Cedric Desire
• Van Kraaij Markus Gerardus Martinus Maria

Classifications

• G03F7/706849

  Irradiation branch, e.g. optical system details, illumination mode or polarisation control · CPC title

• G03F7/706851

  Detection branch, e.g. detector arrangements, polarisation control, wavelength control or dark/bright field detection · CPC title

• G03F9/7034

  Leveling · CPC title

• G03F7/7065

  Defects, e.g. optical inspection of patterned layer for defects · CPC title

• G03F7/70633

  Overlay, i.e. relative alignment between patterns printed by separate exposures in different layers, or in the same layer in multiple exposures or stitching · CPC title