Optical critical dimension metrology

Patent metadata

Field	Value
Publication number	US-2016363484-A1
Application number	US-201515120847-A
Country	US
Kind code	A1
Filing date	Feb 23, 2015
Priority date	Feb 23, 2014
Publication date	Dec 15, 2016
Grant date	—

Abstract

A metrology system is presented for measuring parameters of a structure. The system comprises: an optical system and a control unit. The optical system is configured for detecting light reflection of incident radiation from the structure and generating measured data indicative of angular phase of the detected light components corresponding to reflections of illuminating light components having different angles of incidence. The control unit is configured for receiving and processing the measured data and generating a corresponding phase map indicative of the phase variation along at least two dimensions, and analyzing the phase map using modeled data for determining one or more parameters of the structure.

First claim

1 . A metrology system for measuring parameters of a structure, the system comprising:
an optical system configured for detecting light reflection of incident radiation from the structure and generating measured data indicative of angular phase of the detected light components corresponding to reflections of illuminating light components having different angles of incidence, and a control unit configured for receiving and processing the measured data and generating a corresponding phase map indicative of the phase variation along at least two dimensions, and analyzing the phase map using modeled data for determining one or more parameters of the structure.

2 . A metrology system according to claim 1 , wherein said at least two dimensions comprise angular data on the structure along the two axis.

3 . A metrology system according to claim 1 , wherein said at least two dimensions comprise angular data on the structure along one axis and spectral data.

4 . A metrology system according to claim 2 , wherein said at least two dimensions comprise position data on the structure along the two axis and additionally comprise spectral data.

5 . A metrology system according to any one of the preceding Claims, wherein said optical system is configured and operable for illuminating the structure with one or more wavelength, and detecting the light reflection for said one or more wavelengths.

6 . A metrology system according to claim 5 , wherein said optical system is configured and operable for illuminating the structure with multiple wavelength, either concurrently or sequentially.

7 . A metrology system according to any one of the preceding claims, wherein the optical system is configured for illuminating the sample with light of a specific polarization, and detecting reflected light of orthogonal polarization.

8 . A metrology system of any one of the preceding claims, wherein the optical system comprises a phase detector.

9 . A method for use in measurements of one or more parameters of a structure, the method comprising:
providing measured data indicative of angular phase of light components corresponding to reflections of illuminating light components having different angles of incidence onto the structure; processing the measured data and determining a corresponding phase map indicative of the phase variation along at least two dimensions, and analyzing the phase map using modeled data for determining one or more parameters of the structure.

Assignees

• Nova Measuring Instr Ltd

Inventors

• Barak Gilad
• Shafir Dror
• Grossman Danny

Classifications

• G01N21/21

  Polarisation-affecting properties (G01N21/19 takes precedence) · CPC title

• G01J9/00 Primary

  Measuring optical phase difference (devices or arrangements for controlling the phase of light beams G02F1/01); Determining degree of coherence; Measuring optical wavelength (spectrometry G01J3/00) · CPC title

• G01B2210/56

  Measuring geometric parameters of semiconductor structures, e.g. profile, critical dimensions or trench depth · CPC title

• G01N2201/12

  Circuits of general importance; Signal processing · CPC title

• G01B11/02

  for measuring length, width or thickness (G01B11/08 takes precedence) · CPC title