Beam profile reflectometry: A new technique for dielectric film measurements

Rosencwaig, Allan; Opsal, Jon; Willenborg, D. L.; Kelso, S. M.; Fanton, J. T.

doi:10.1063/1.107323

Cited by 50 publications

(18 citation statements)

References 3 publications

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“…16,17 It measures reflectance for different wavelength to calculate thickness. This technique can only determine the film thickness and it is a point detection technique. Recently, reflectometry and spectrally resolved white light interferometry were combined for measurement of film thickness and surface profile using Linnik interferometer.…”

Section: Introductionmentioning

confidence: 99%

Determination of film thickness and surface profile using reflectometry and spectrally resolved phase shifting interferometry

Debnath

You

Kim

2009

Int. J. Precis. Eng. Manuf.

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Surface profiling and film thickness measurement play an important role for inspection in semi conductor industry. White light source had been used as scanning white light interferometry and spectrally resolved white light interferometry for determining surface and film thickness profile. These techniques however failed for thinner film. Recently, reflectometry and spectrally resolved white light interferometry was combined for the same. This technique used Fourier Transform for the calculation of phase in spectral domain with the use of Linnik interferometer. In this method a large amount of carrier offset (carrier fringes) is required to be effective. This carrier fringes in spectrally resolved white light interferometry was achieved by increasing the optical path difference between the test and the reference surface. But, Linnik interferometer cause defocusing problem to create these carrier fringes. We propose in this paper to combine reflectometry and spectrally resolved phase shifting interferometry for measurement of surface and film thickness profile with the use of Michelson objective. Michelson objective will be convenient to implement as compared to the Linnik type and the use of phase shifting interferometry does not necessarily need large number of fringes in the spectral domain.

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Section: Introductionmentioning

confidence: 99%

Determination of film thickness and surface profile using reflectometry and spectrally resolved phase shifting interferometry

Debnath

You

Kim

2009

Int. J. Precis. Eng. Manuf.

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“…The reflected beam goes through several beam splitters (BS4, BS2 and BS3), and then pass through a quarter wave plate, before being collected by a high resolution CCD camera. This optical characterization technique, that we call Reflectometry at Profile Level (RPL), was developed in collaboration with Nightingale EOS [9], and it is a variation of two former techniques, Beam Profile Reflectometry and Beam Profile Ellipsometry [10][11][12]. The more remarkable characteristics are that the system collects the reflectivity of a variety of angles of incidence and polarization states with a single measurement, and with a sub-micrometric spot size.…”

Section: Methodsmentioning

confidence: 99%

Sub-micrometric reflectometry for localized label-free biosensing

Casquel¹,

Soler²,

Holgado³

et al. 2015

Opt. Express

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In this work we present an optical technique for characterizing sub-micrometric areas based on reflectivity of the light as a function of angle of incidence for the two pure polarizations s and p, covering a range of angles of incidence from −71.80° to 71.80° with a resolution of 0.1°. Circular areas with a diameter in the order of 600 nm can be characterized, and the spectra for the two polarizations can be obtained with a single measurement. For biosensing purposes, we have fabricated several Bio Photonic Sensing Cells (BICELLs) consisting of interferometers of 1240 nm of SU-8 polymer over silicon. An indirect immunoassay is performed over these BICELLs and compared experimentally with FT-VIS-NIR spectrometry and theoretical calculations. The Limit of Detection (LoD) achieved is comparable with standard high resolution spectrometry, but with the capability of analyzing sub-micrometric domains for immunoassays reactions onto a sensing surface.

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“…Reflection spectrophotometry is very limited making simultaneous optical parameter measurements because of the dispersion of the index of refraction and coefficient of extinction with wavelength. (62) This technique also requires that the film surface is relatively smooth, as rough surfaces will contribute significant error to the measurement. However, despite these shortcomings, reflection spectrophotometry is an extremely robust and cost effective technique for thickness measurements when appropriate parameters are present.…”

Section: 23layer Thicknessmentioning

confidence: 99%

“…In contrast to reflection spectrophotometry, measurements are made at various angles at a particular wavelength. (62) Multi-angle measurements are usually made simultaneously using a microscope objective. This technique provides greater precision and reliability then reflection spectrophotometry.…”

Section: 23layer Thicknessmentioning

confidence: 99%