Silicon Wafer Microscope

The Clear Choice For Your Innovative Applications

n&k Technology, Inc., of San Jose, California, was founded in 1992 by Drs. Rahim Forouhi and Iris Bloomer. The company manufactures exceptionally high resolution, state-of-the-art scatterometry (OCD) and thin film metrology tools for the semiconductor, photomask, data storage, flat panel display and solar cell industries. n&k’s large family of tools provide measurements for a large range of OCD and thin film structures that cover current and future applications, and are used for the most challenging applications of today’s high tech industries.

The n&k Premise

THE Recipe for Successful Scatterometry and Thin Film Measurements:

Optimal Raw Data:

Start with excellent raw data with optimized signal-to-noise ratio over the widest possible wavelength range, either from 190nm –1,000nm or 190nm – 15,000nm.

Optical design involves n&k’s patented reflective optics to optimize the number of photons (signal) reaching the detector, thus creating excellent signal-to-noise of the measured raw data.

Combined With Analysis

The physically valid Forouhi-Bloomer (F-B) Dispersion Equations for n and k, are utilized for thin film analysis.

The F-B equations are combined with the physically valid Rigorous Coupled Wave Analysis (RCWA) for analysis of OCD structures (2D trenches and 3D holes).

Precise Actionable Results

Accurate and precise measurements of the most challenging OCD and thin film structures that cover current and future applications.

Satisfying the n&k premise ensures valid, actionable results.

What They Are Saying

What They Are Saying

The accuracy, speed & ease-of-use of the n&k analyzer was far superior to standard ellipsometry. Quite frankly, I don’t know of any other machine which can provide so much information, so accurately and so quickly.
Dr. Joseph Kennedy
Product Integration Manager
Honeywell Corporation
What I really like about the n&k system is its very powerful engine but at the same time it’s very user friendly. The technical support from n&k is great when something does go wrong, which is rare, as good as the machine is.
Robert Herrick
Process Engineer, R&D Group
Fairchild Semiconductor, Utah
RTC recently bought a 1512-RT n&k tool for phase, transmission, reflectivity, and resist thickness measurements and it’s a great tool. Greg Hughes, Jeff Myron, and myself have all worked with it recently and can’t say enough good
things about it.
Dr. Rusty Cantrell
Member of Technical Staff
Du Pont Photomask (now Toppan) Round Rock, Texas
Thank you for your e-mail. I’m also thanking your company and all members of your company. It’s no problem to write about our experience of your RT system, because I personally think that your system was greatly helpful in my research and to our company.
Dr. Donggun Lee
Senior Engineer, Photomask Team
Samsung Electronics, Korea
Faculty and students at Fudan University are making extensive use of the n&k 8000 for thin film measurements and also when conducting research, writing technical papers and theses. Thank you very much for your support.
Dr. Sue Jiang
Professor of Materials Science
Fudan University, Shanghai, China
A CD measurement with the n&k analyzer provides a high throughput, non-destructive and accurate method for the determination of the critical dimensions and depths of periodic structures like trenches and resist gratings.
Dr. Franz Heider et al,
Principal Specialist Metrology, Infineon Technologies AG
2012 SEMI Advanced Semiconductor Manufacturing Conference (ASMC)

Our Executive Team

Dr. Rahim Forouhi

Co-Founder and Chief Executive Officer

Dr. Rahim Forouhi is responsible for overseeing n&k’s overall business direction as well as driving the technical expertise in broadband spectrophotometry, semiconductor processing and optical instrumentation.

Dr. Forouhi holds a patent based on what is known in current scientific literature as the Forouhi-Bloomer optical dispersion equations. Together with n&k co-founder Dr. Iris Bloomer, he developed the patented “n&k Method,” a spectrophotometric method utilizing the Forouhi-Bloomer optical dispersion equations for simultaneously determining thickness, index of refraction, extinction coefficient and the energy band gap for a variety of thin films, semiconductors, optical coatings and flat panel displays. A pioneer in his field, Dr. Forouhi has authored or co-authored 42 issued patents for semiconductor processing, optical instrumentation and optical characterization of materials, and has written numerous technical publications.

Dr. Forouhi received his Ph.D. in Materials Science from the University of California, Berkeley. He holds a Masters in Physics from the University of Oslo, Norway, and a Bachelor of Science degree in Physics from the first graduating class of Aryamehr University of Technology in Tehran, Iran.

Dr. Iris Bloomer

Co-Founder and Executive Vice President

Dr. Iris Bloomer is responsible for n&k’s strategic sales and marketing direction. Before co-founding n&k Technology, Dr. Bloomer spent the past 17 years as Professor of Physics at San Jose State University and is currently Professor-Emerita. She has authored numerous technical publications and serves on the technical advisory board of Vacuum & Thin Film.

Dr. Bloomer holds a patent for what is known in current scientific literature as the Forouhi-Bloomer optical dispersion equations. Together with n&k co founder, Dr. Rahim Forouhi, she developed the patented “n&k Method” a spectrophotometric method utilizing the Forouhi-Bloomer optical dispersion equations for simultaneously determining thickness, index of refraction, extinction coefficient and the energy band gap for a variety of thin films, Semiconductors, Optical Coatings and Flat Panel Displays.

Dr. Bloomer received her doctorate in Physics in the area of General Relativity from the University of London and was awarded a Masters degree in Physics, instead of the Bachelor of Arts degree, by Temple University.

Company History

Until the early 1980s mathematical algorithms not derived from first principles, such as the Cauchy equations, were used to determine the refractive index (n) and the extinction coefficient (k) as a function of wavelength. Such equations were valid only for a very limited range of wavelengths, and became difficult to apply as technology advanced.

Dr. Rahim Forouhi, President and co-founder of n&k, starting from first principles, deduced physically valid equations for the calculations of n and k. These equations are referred to, in current scientific literature, as Forouhi-Bloomer Equations, as n&k co-founder Dr. Iris Bloomer was simultaneously working with Dr. Forouhi to develop the physical significance of the equations.

The Forouhi-Bloomer model is a physically valid universal set of equations for n and k as functions of wavelengths that require far fewer parameters than any other model to fit experimental data over any wavelength, from the Extreme Ultra-Violet (EUV) to Infra-Red (IR) regime. These equations are applicable to all thin film materials and substrates, even inhomogeneous films.

It was obvious to Dr. Forouhi and Dr. Bloomer that even with their discovery of universal equations for n and k, unless the measured raw data had excellent signal-to-noise ratio, poor results would be obtained. They solved the problem by introducing their patented all-reflective optics that contain no light absorbing components such as refractive lenses and beam splitters. Most of the collected light reaches the detector to produce the strongest signal-to-noise ratio available in the industry today. With the Forouhi-Bloomer Equations for n and k combined with innovative all-reflective optics, it became possible for the first time in history, to accurately analyze measured reflectance of thin films, data collected over the entire DUV-Vis-NIR regime, with one single set of equations, and simultaneously determine film thickness and n and k spectra, from 190nm to 1000nm. Recognizing the potential market opportunity that their discovery created, Forouhi and Bloomer founded n&k Technology in 1992.
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