With the development of science and technology, the precision requirements of products in various fields are getting higher and higher. After continuous research and development and testing, the Atometrics technical team officially released the [Film Thickness Measuring Instrument AF-3000 Series]. The ultra-high precision measurement parameters and multi-layer film measurement capabilities meet the film measurement needs of various industries, and help the manufacturing and iteration of products in various industries and the progress of the times.

Want to know how Atometrics thin film measuring instrument measures the thickness of thin films? How thin a film can it measure? Today, Dr. Atometrics will answer your questions!

01 Measurement Principle

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

When the phase difference is an integer multiple of the wavelength, constructive superposition occurs, and the reflectivity is maximum at this time;

When the phase difference is half a wavelength, destructive superposition occurs, and the reflectivity is lowest;

The superposition of integer multiples and half a wavelength has a reflectivity between the maximum and minimum reflection.

The change of this phase difference depends on the thickness d of the film and the refractive index n. The optical parameter (n,k) value of the known material can deduce the reflectivity R (λ, d, n, k) of this optical system.

When the optical parameters (n, k) are assigned in the device, the reflectivity R can be calculated and compared with the reflectivity R' measured by the device. When the reflectivity curve R and the measured reflectivity R' curve are perfectly fitted, the thickness d of the film can be obtained by analyzing the interference pattern.

Schematic diagram of the principle of the Atometrics film thickness measuring instrument

In summary, theoretically, only films made of transparent or translucent materials can be penetrated by light waves, and thus can be measured with a film thickness measuring instrument. However, some opaque materials, such as metals, can also be measured under certain circumstances. When the metal film is only a few hundred nanometers or even a few nanometers thin, it can also be partially penetrated by light waves, and the thickness of the film can then be accurately measured.

02 Product Advantages

(1) Ultra-high precision, resolution 1Å

The Atometrics AF-3000 series abandons the traditional overall band fitting and adopts a unique "band-by-band fitting algorithm" to accurately correct the deviation and significantly reduce the deviation of the ultraviolet band, thus achieving an ultra-high resolution of 1Å.

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

(2) Multi-layer measurement, stable spectrum

The Atometrics AF-3000 series abandons the traditional LED light source and adopts "deuterium lamp" and "tungsten halogen lamp" with uniform light intensity and stable channels. It supports the measurement of single-layer film, multi-layer film, liquid film, air gap layer, rough/smooth layer, refractive index, and can measure up to 10 layers of film. One machine covers the measurement range of multiple machines, and the measurement results are more accurate.

(3) Applicable to multiple scenario configurations

The Atometrics AF-3000 series supports multiple measurement scenarios including offline, online, mapping mode, and fully automatic. It can also be customized to meet customers' additional needs for actual applications. It also provides after-sales debugging and software development assistance services.

03 Application fields and industry needs

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

Silicon dioxide film and calcium fluoride film in the precision optics industry;

Case 1:

Recently, Atometrics received a sample from a university, hoping to measure the metal nickel film on the surface of the silicon wafer for research purposes. The thickness is only a few nanometers! After learning the customer's needs, the engineer used the Atometrics film thickness measurement AF-3000 series to test the customer and obtained the following results:

It can be seen that the AF-3000 series has very stable light waves during the measurement process, and the thickness of the Ni film detected is about 3.5nm, with a matching degree of 0.009081!

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

"I didn't expect Atometrics to have such a high level of attainment in the field of film thickness measurement, and the measurement results are so accurate. This is of great help to our research. Thank you very much for the professionalism and timeliness of Atometrics engineers." After receiving the test report, the customer praised the Atometrics film thickness measuring instrument.

Case 2:

A research institute hopes to detect the thickness of PI film with an accuracy requirement of 0.1nm. After learning the customer's needs, the Atometrics engineer used the Atometrics film thickness measurement AF-3000 series to test the customer and obtained the following test results:

 Thickness measurement results of PI film on ceramic substrate

Thickness measurement results of PI film on copper

As can be seen in the figure, the thickness of the PI film on the ceramic substrate is 4602.4nm, and the matching degree is 0.009079! The thickness of the PI film on the copper is 29657.2nm, and its matching degree is 0.291977.

The thin film thickness measuring instrument of Atometrics can measure up to 10 layers of film. No matter how many layers of film there are, it cannot hinder the accuracy of Atometrics's measurement!