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Popular Science | How thin can the Atometrics Film Thickness Gauge AF-3000 Series measure?


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With the increasing development of science and technology, the precision requirements of products in various fields are getting higher and higher. After continuous research and development and experimentation, UCOMETRIC technical team has officially released [Film Thickness Measuring Instrument AF-3000 Series], with ultra-high precision measurement parameters and multi-layer film measurement capability, which meets the film measurement needs of various industries, and assists in the manufacturing and iteration of products and the progress of the times in various industries.

Want to know how Atometrics' Thin Film Gauge measures film thickness? How thin a film can it actually measure? Today Dr. Youkai is here to answer your questions!

01 Measurement Principles

The AF-3000 series instruments emit light waves of different wavelengths to penetrate the sample membrane layer, and the reflected light from the upper and lower surfaces of the membrane is received by the instrument, and the phase difference between the reflected light and each other is enhanced or weakened.

Constructive superposition occurs when the phase difference is an integer multiple of the wavelength, when the reflectivity is greatest;

A phase difference of half a wavelength produces a destructive superposition with the lowest reflectance;

A superposition of an integer multiple of half a wavelength, where the reflectivity is between the maximum and minimum reflectivity.

The variation of this phase difference, depending on the thickness d of the film and the refractive index n the value of the optical parameter (n,k) of the known material, allows the derivation of the reflectivity R(λ,d,n,k) of this optical system.

When the optical parameter (n,k) is assigned a value in the device, the reflectance R can be calculated so that it is compared with the measured reflectance R' of the device, which is calculated by a strong algorithm, and when the reflectance curve R is perfectly fitted to the measured reflectance R' curve, the thickness d of the film can be obtained by analyzing the interference pattern.

Schematic diagram of Ucometer Film Thickness Gauges

In summary, theoretically, only films made of transparent or semi-transparent materials can be penetrated by light waves, and thus can be measured with a film thickness gauge. But some opaque materials, such as metal in some cases can also be measured, when the metal film is only a few hundred nanometers or even a few nanometers thin, can also be part of the light wave penetration, which will be able to accurately measure the thickness of the film.

02 Product Advantages

(1) Ultra-high precision 1Å resolution

The Atometrics AF-3000 series abandons the traditional whole-band fitting and adopts a unique "split-band fitting algorithm", with precise bias correction and a significant reduction in UV band bias, thus realizing ultra-high resolution 1Å.

What is the concept of 1Å? The diameter of a normal human hair is about 60 μm, and 1Å is equivalent to one six hundred thousandth of the diameter of a hair!

(2) Multi-layer measurement Spectral stabilization

The Atometrics AF-3000 series uses deuterium and tungsten halogen lamps with uniform light intensity and channel stability, instead of traditional LED light sources, and supports the measurement of monolayers, multilayers, liquid membranes, air gaps, rough/smooth layers, refractive index, and refractive index of up to 10 layers. The machine supports the measurement of single-layer films, multi-layer films, liquid films, air-gap layers, rough/smooth layers, refractive index, and up to 10 layers. One machine covers the measurement range of several machines, which makes the measurement results more accurate.

(3) Suitable for multi-scenario configuration

The Atometrics AF-3000 series supports a wide range of measurement scenarios, including offline, inline, Mapping mode, fully automated, and can be customized to meet additional needs for real-world applications. We also provide after-sales commissioning and assistance in software development.

03 Areas of application and industry needs

Currently, film thickness measurement has a wide range of applications in various industries involving:

Silicon Dioxide film and Calcium Fluoride film in the precision optics industry, etc;

Quantum dot chips, photoresists, GaN coatings, etc. for the semiconductor industry;

Chalcogenide, ITO, etc. for new energy/photovoltaic industry;

Coated films, micro runners, etc. for the display panel industry;

Surface coating layer for the tool industry;

PI film in the polymer material industry and so on.

04 Applications

Case 1:

Recently, Atometrics received a sample from a university to measure a nickel metal film coated on the surface of a silicon wafer for research use, with a thickness of only a few nanometers! Engineers learned of the customer's needs, the use of UCOMETRIC film thickness measurement AF-3000 series for the customer to do the test, resulting in the test is as follows:

Nickel Film Thickness Measurement Results

It can be seen that the AF-3000 series has a very stable light wave during the measurement process and detects the Ni film thickness of about 3.5nm with a match of 0.009081!

Even though a few nanometers of metal film is very thin, this is not the limit of Atometrics' measurement capabilities! Atometrics' film thickness gauges have an ultra-high resolution of 1Å and an accuracy of 0.1nm, which means that even if the film is only 1nm thick, our gauges can accurately measure it!

     "I didn't expect Atometrics to have such high attainments in film thickness measurement and such accurate measurement results, which will be of great help to our research, many thanks to Atometrics engineers for their professionalism and promptness." The customer received the test report and was full of praise for Atometrics' film thickness gauges.

Case 2

A research institute wanted to test the film thickness of PI film with an accuracy of 0.1 nm. After learning about the customer's needs, UCOMETRIC engineers used Atometrics Film Thickness Measurement AF-3000 series to do the test for the customer, and the test results are as follows:

Measurement results of PI film thickness on ceramic substrate

Measurement results of PI film thickness on copper

As can be seen in the figure, the PI film thickness on the ceramic substrate is detected as 4602.4nm, with a match of 0.009079! The film thickness of the PI film on the copper is detected as 29657.2nm, with a match of 0.291977.

     Atometrics' Film Thickness Gauges measure up to 10 layers of film, so no number of layers can stop the accuracy of Ucometer's measurements!

If you are interested in the above applications.

Welcome to call 400-0803885 service number.

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