Multiparameter measurements of thin films using beam-profile reflectometry

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

doi:10.1063/1.352421

Cited by 29 publications

(15 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Introduced by Therma-Wave Inc. in 1991 6,7 , this technology uses a laser beam incident upon a sample through a high numerical aperture lens to provide illumination at a range of angles-of-incidence (typically from normal up to around 60°) simultaneously. The spatial profiles of the reflected laser beam along its two principal axes (parallel and perpendicular to the polarization direction) are analyzed in order to obtain plots of reflectance as a function of angle of incidence for s and p polarized light independently.…”

Section: Beam Profile Reflectometry (Bpr)mentioning

confidence: 99%

A laser reflectometry technique for on-device coating thickness measurements

Morris¹

2010

SPIE Proceedings

View full text Add to dashboard Cite

We demonstrate the use of Beam Profile Reflectometry (BPR) to measure coating thicknesses on small, highly curved devices such as cardiac stents. BPR has long been used in the semiconductor industry as a powerful technique for measuring the thickness and refractive index of transparent films. The method uses a diffraction-limited focused laser beam to provide light at multiple angles-of-incidence simultaneously within a sub-micron measurement area. By analyzing the reflected light as a function of angle-of-incidence and polarization, robust and deterministic measurements of film-thickness and refractive index can be obtained taking proper account of birefringence.For the current work, the technique has been implemented in a compact desktop configuration suitable, for example, for the in-line monitoring of coating thickness and composition as part of a stent manufacturing process. Provision is made for the alignment and manipulation of the small and fragile samples, and for the location of the measurement spot at the appropriate site on the stent's surface.Validation measurements on stent-like reference samples, comparing results from the technique with destructive measurements on the same samples, show correlation of better than 99% over a range of coating thicknesses and sample morphologies down to curvature radii of ~50μm.

show abstract

Section: Beam Profile Reflectometry (Bpr)mentioning

confidence: 99%

A laser reflectometry technique for on-device coating thickness measurements

Morris¹

2010

SPIE Proceedings

View full text Add to dashboard Cite

show abstract

“…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

View full text Add to dashboard Cite

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.

show abstract

“…Eq. (1) has been previously applied for measuring the thickness and optical properties of films in stacks using different techniques as beam profile reflectometry, beam profile ellipsometry or spectroscopic beam profile ellipsometry [13,14].…”

Section: í Id Model Explanationmentioning

confidence: 99%

Efficient design and optimization of bio-photonic sensing cells (BICELLs) for label free biosensing

Lavín¹,

Casquel²,

Sanza³

et al. 2013

Sensors and Actuators B: Chemical

View full text Add to dashboard Cite

In previous works we demonstrated the benefits of using micro-nano patterning materials to be used as bio-photonic sensing cells (BICELLs), referred as micro-nano photonic structures having immobilized bioreceptors on its surface with the capability of recognizing the molecular binding by optical transduction. Gestrinone/anti-gestrinone and BSA/anti-BSA pairs were proven under different optical configurations to experimentally validate the biosensing capability of these bio-sensitive photonic architectures. Moreover, Three-Dimensional Finite Difference Time Domain (FDTD) models were employed for simulating the optical response of these structures. For this article, we have developed an effective analytical simulation methodology capable of simulating complex biophotonic sensing architectures. This simulation method has been tested and compared with previous experimental results and FDTD models. Moreover, this effective simulation methodology can be used for efficiently design and optimize any structure as BICELL. In particular for this article, six different BICELL' S types have been optimized. To carry out this optimization we have considered three figures of merit: optical sensitivity, Q-factor and signal amplitude. The final objective of this paper is not only validating a suitable and efficient optical simulation methodology but also demonstrating the capability of this method for analyzing the performance of a given number of BICELLs for label-free biosensing.

show abstract

Multiparameter measurements of thin films using beam-profile reflectometry

Cited by 29 publications

References 4 publications

A laser reflectometry technique for on-device coating thickness measurements

A laser reflectometry technique for on-device coating thickness measurements

Sub-micrometric reflectometry for localized label-free biosensing

Efficient design and optimization of bio-photonic sensing cells (BICELLs) for label free biosensing

Contact Info

Product

Resources

About