Combining phase and coherence information for improved precision in white-light interference microscopy requires a robust strategy dealing with the inconsistencies between these two types of information. We correct on every measurement by direct analysis difference map profiles. The algorithm adapts to surface texture noise level dynamically compensates optical aberrations, distortions, diffraction, dispersion that would otherwise lead incorrect fringe order. same also provides absolute...

We propose a computationally efficient theoretical model for low-coherence interferometric profilers that measure surface heights by scanning the optical path difference of interferometer. The incorporates both geometric and spectral effects means an incoherent superposition ray bundles through interferometer spanning range wavelengths, incident angles, pupil plane coordinates. This sum is efficiently performed in frequency domain, followed Fourier transform to generate desired simulated...

We propose a practical theoretical model of an interference microscope that includes the imaging properties optical systems with partially coherent illumination. show effects on measured topography spatially extended, monochromatic light source at low numerical apertures can be approximated in simplified assumes and linear, locally shift-invariant transfer function accounts for aberrations attenuation diffracted plane wave amplitudes increasing spatial frequencies. Simulation instrument...

Lateral resolving power is a key performance attribute of Fizeau interferometers, confocal microscopes, interference and other instruments measuring surface form texture. Within well-defined scope applicability, limited by slope, texture, continuity, linear response model provides starting point for characterizing spatial resolution under ideal conditions. Presently, the instrument transfer function (ITF) standardized way to quantify height variations as frequency. In this paper, we build on...

We describe an instrument for the measurement of surface flatness, parallelism, and size (thickness) plane-parallel parts in a single to 1sigma gauge capability 0.02, 0.03, 0.06 microm, respectively. A low-coherence IR profiler viewing both sides part simultaneously, believed be novel, accommodates wide variety industrial finishes, including machined, ground, or lapped parts, with 75-mm field view 15,000 pixels per side. heterodyne laser displacement together integrated zeroing system allows...

A white-light interferometer with new signal analysis techniques provides 3D top surface and thickness profiles of transparent films. With an additional change from conventional object imaging to pupil-plane imaging, the same instrument platform detailed properties multilayer film stacks, including material optical properties. These capabilities complement surface-topography measurements on platform, resulting in a highly flexible tool.

The Fourier components of interference signals generated by scanning a high-numerical-aperture objective orthogonal to an object surface correspond different angles incidence on the surface. phase and amplitude these relate structure object, including in particular 3D topography thickness profiles thin-film layers.

Rigorous coupled wave analysis (RCWA) interprets 3D white-light interference microscopy profiles and reveals the dimensions of optically-unresolved surface features. Measurements silicon etch depth a 450-nm pitch grating structure correlate to atomic force with R(2)= 0.995 repeatability 0.11nm. This same technique achieves <1nm sensitivity 80-nm lateral widths 190-nm gratings using 570-nm mean wavelength.

A simple, yet powerful, means of computing the phase fringe patterns depicting dynamic phenomena is presented. It shown that basic principle phase-shifting methods can be extended to case situations. The crux recognize phenomenon under examination itself provide necessary incremental shifts. This new method possesses a very wide range applications in field deformation measurement.

Advances in the implementation of coherence scanning interferometry have dramatically extended range application for this well-known technique. New data acquisition and processing methods significantly improve dynamic range, enabling measurements steeply-sloped surfaces usually considered beyond reach high-NA objectives. Hybrid incorporating sinusoidally-modulated phase shifting reduces signal-to-noise to 0.1 nm/√Hz level, extending technique super-polished surfaces.

We review definitions of optical resolution and how they relate to the Instrument Transfer Function surface profiling interferometers. The corresponding cutoff provides a selection criterion for given metrology application (PSD, waviness).

Interferometers for the measurement of surface form and texture have a reputation high performance. However, results many types features can deviate from expectation one cycle phase shift per half wavelength height. Here we review fundamentals imaging interferometry describe ways defining instrument response, including linear transfer function. These considerations define practical regimes behavior that are usually satisfied traditional uses interferometers; but increasingly challenged by...

The measurement of shape, displacement and deformations is often performed using interferometric methods, featuring nm to mm sensitivities very high spatial temporal resolutions. We first give a brief overview techniques. Emphasis laid on the wide purposes these Then, we present novel method wavelet analysis process live interference patterns. Further developments are then presented. Finally, through two practical examples, intend highlight interest fringe processing by transform.

We report on characterization techniques for microstructures using white-light interference microscopy. Capabilities include surface profilometry, integrated profilometry and lateral metrology full 3D characterization, defect detection, of thin film structures, stroboscopic interferometry vibrating samples, real-time profile snapshots moving MEMS devices.

Pupil-Plane Scanning White-Light Interferometry measures reflectivity as a function of angle incidence, wavelength and polarization in one location an object surface. This information is converted into ellipsometric allows the characterization material optical properties layer thickness case layered structures. We illustrate capability method by measuring refractive index thin film standards. The also used to create accurate 3D topography maps complex

We model the measurement process in an interference microscope and derive libraries of signal signatures corresponding to various types materials thin film structures. These allow calculating top surface topography patterned wafer features as well thickness underlying transparent layer with nanometer height resolution. show applications technique trenches etched SiO2 films, post‐CMP STI patterns line The results optical profiler are good agreement AFM ellipsometer measurements nearby

Optical 3D profilers based on Coherence Scanning Interferometry (CSI) provide high-resolution non-contact metrology for a broad range of applications. Capture true color information together with topography enables the detection defects, blemishes or discolorations that are not as easily identified in data alone. Uses imaging include image segmentation, dissimilar materials and edge enhancement. This paper discusses pros cons capture using standard detectors presents an alternative solution...

We propose a model for coherence scanning interferometry using familiar Fourier optics methods and the spectrum of plane waves case where light source spectral bandwidth limits fringe contrast as function optical path length. The is straightforward to implement, computationally efficient, reveals many common error sources related filtering properties imaging system. quantify applicability geometrical approximations optics, particularly high numerical apertures, when determining surface...

We describe techniques for measuring step heights between separated, nominally plane-parallel surface regions of a precision-engineered part. Our technique combines broadband, 10-micron wavelength scanning interferometric profiler with HeNe laser displacement gage. The infrared accommodates machined metal parts having roughness in excess what would be possible visible-wavelength interferometer. combination broadband interferometry, which removes fringe order ambiguity, gage makes it to...

A theoretical model of the optical system an interference microscope includes both geometrical and spectral contributions to fringe contrast localization. An incoherent superposition patterns over a range wavelengths pupil-plane coordinates predicts frequency-domain portrait phenomenon. inverse Fourier transform then provides simulated signals that correlate very closely experimental data. The is particularly useful for signal prediction, algorithm testing, uncertainty analysis...

We compare two modes of measurement shallow objects using a scanning interference microscope. In one mode the object is moved with respect to Mirau objective while camera records pattern. another beam splitter during scan remains in focus. use both narrowband and broadband extended LED sources for experiments modified 0.8-NA objective. A detailed analysis low-coherence signals spatial spectral domains reveals small differences between mode. However, comparison surface profiles having...