Research Papers

The Zygo research team is committed to publishing their latest research in the scientific and optical metrology communities.

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Research Paper

Step height measurements using a combination of a laser displacement gage and a broadband interferometric surface profiler

This article describes techniques for measuring step heights between separated, nominally plane-parallel surface regions of a precision-engineered part. Our technique combines a broadband, 10-micron wavelength scanning interferometric profiler with a HeNe laser displacement gage.

Jun 19, 2002

Research Paper

Absolute distance measurements using FTPSI with a widely tunable IR laser

This article describes how fourier transform phase-shifting interferometry is further developed and applied to the absolute measurement of interferometer cavities.

Jun 19, 2002

Research Paper

Combined advanced finishing and UV-laser conditioning for producing UV-damage-resistant fused-silica optics

This article lays out details of the advanced finishing procedures are described and comparisons are made between the procedures based upon large area 3(omega) damage performance, polishing layer contamination, and optical subsurface damage.

Apr 9, 2002

Research Paper

New algorithm for optical photomask CD metrology for the 100-nm node

This paper presents a new CD metrology algorithm that is highly linear and largely insensitive to the influence of OPE while maintaining high precision and repeatability. The algorithm has been implemented on the new 244nm DUV optical metrology tool, the KMS-100. Demonstrated performance for the new algorithm on the DUV tool on binary masks shows better than 1.5nm, 3 sigma static repeatability down to 0.25um.

Mar 11, 2002

Research Paper

Multiple-surface phase-shifting interferometry

The author shows how phase shifting interferometry can be extended to account for multiple interference effects using a Fourier based analysis technique combined with wavelength tuning and a particular four-surface interferometer geometry.

Dec 27, 2001

Research Paper

Interferometric measurements of back focal length and insertion loss of precision microlens arrays

In this paper, we describe interferometric techniques for measuring the BFL and IL of all elements in a microlens array, and we document the measurement precision.

Nov 13, 2001

Research Paper

Unusual techniques for absolute distance measurement

In this article, the author describes four unusual laser systems for absolute measures of linear distance.

Jan 1, 2001

Research Paper

Measurement of Transparent Plates with Wavelength-Tuned Phase-Shifting Interferometry

This article analyzes when a wavelength-toned Fizeau interferometer is applied to the problem of flatness testing of transparent plates.

Jul 1, 2000

Research Paper

Diffractive grazing-incidence interferometer

In this article, the author proposes a symmetric geometry for grazing-incidence interferometry of flat surfaces using diffraction gratings for beam splitting and recombination.

Apr 1, 2000

Research Paper

Optical proximity effects in submicron photomask CD metrology

This paper models several imaging systems using the Optical Transfer Function analysis method and discusses some results from an ongoing study to devise methods for calibrating CD mask metrology tools, and evaluates several different imaging objects and line measurement algorithms as to their sensitivity to the influences of OPE in the measurement of binary masks.

Feb 3, 2000

Research Paper

Geometrically desensitized interferometry for shape measurement of flat surfaces and 3-D structures

In this article, the authors construct an interferometer for flatness testing of precision-engineered objects such as rigid disk drive platters, pump parts, and fuel injectors.

Jan 1, 2000

Research Paper

A High-Accuracy Multi-Channel Fiber-Based Displacement Distance Measuring Interferometer System

This paper describes a high-accuracy, high stability multi-channel fiber-based interferometer system with compact sensors that combines high-accuracy displacement and absolute distance measuring capability.

Jan 1, 2000