Quick and accurate non-contact testing of thin films
Eddy current testing is a non-destructive method, which has long proved its effectiveness in aircraft construction, railway transport, pipe production and other industries. Its use for quality control of thin films allows to significantly reduce the time and improve the accuracy of measurements. If at the conventional 4-point-probe testing the sample is inevitably damaged and becomes unusable, then the contactless eddy current method does not affect the characteristics of the controlled object. An important advantage over conventional technologies is also the ability to automate measurements including inline testing using a movable or fixed sensor. In the case of installation of measuring systems in process equipment, the spot check is replaced by a continuous control of each wafer or part, which increases the reliability of the process and product quality. The eddy current method can be used to control various conductive materials from metals and alloys to carbon fibers.
The eddy current method makes it possible to determine the sheet resistance and thickness of thin films. The sheet resistance characterizes the specific electric conductivity of the film, the value of which is especially important for electrodes and conductive layers. Control of sheet resistance and thickness of thin films with the help of our devices allows to switch to using cheaper materials, optimize the size of substrates, increase productivity and reduce costs. Since the time of one measurement is several milliseconds, it is possible to quickly build electrical conductivity maps that make it possible to evaluate the uniformity of a thin film, to reveal thickness deviations and structural defects. Optionally, it is possible to measure the optical transparency of the surface, as well as the electrical anisotropy.
What models of systems are offered to customers?
We supply four series of systems: EddyCus TF portable 1010; EddyCus TF lab for single point measurements in modifications for substrates up to 200Ч200 mm and up to 400Ч400 mm in size; EddyCus TF map SR for obtaining conductivity maps in modifications for substrates up to 250Ч250 mm and up to 500Ч500 mm in size; EddyCus TF inline for inline control.
On the basis of standard tools, special solutions can be created optimized to solve the problems that specific customers face.
In which areas are these systems used?
In total, we have sold more than two thousand systems, quite a large part of which falls on systems using the eddy current testing method. They are in demand in almost all areas where thin films are used, including the production of semiconductor devices, LEDs, optical elements, batteries, displays, 2D materials, sensors, smart glasses, photovoltaics etc.
Interview: Dmitry Gudilin