In the field of precision thin film measurement, measurement accuracy directly determines the level of process control and product yield, making the selection of film thickness gauge brands a focus of attention for many semiconductor, display panel, and new material research and development enterprises. in the marketBrand of film thickness gaugeThere are many different technical routes, and how to evaluate measurement accuracy is an unavoidable issue in procurement decision-making. As a professional service provider with over ten years of experience in precision thin film measurement, Unicon has accumulated rich experience in the selection consultation and technical support of film thickness gauge brands.
1、 The core of precision indicators: nanoscale resolution is the fundamental threshold
To measure the accuracy of a film thickness gauge, it is not enough to rely solely on promotional values. A comprehensive evaluation should be made from four dimensions: resolution, repeatability, accuracy, and stability. Taking the light reflection film thickness gauge as an example, its vertical resolution can reach the nanometer level, with a minimum measurement accuracy of 0.02nm, a minimum stability of 0.05nm, and a maximum accuracy of 1nm or 0.2%. This means that when measuring single-layer transparent films, the device can clearly distinguish thickness differences at the sub nanometer level, which is crucial for process monitoring of key film layers such as semiconductor gate oxide layers and OLED light-emitting layers.
There are significant differences in accuracy indicators among different brands of film thickness gauges. The F20 series universal equipment provided by Nikon has a thickness measurement range of 15nm-70 μ m, which can cover most semiconductor thin film and optical coating scenes; For the F20-UV model designed for ultra-thin films, the lower limit of thickness can be extended to 1nm. The purchaser needs to reverse verify whether the accuracy claimed by the film thickness gauge brand covers the actual measurement range based on their own process nodes.
2、 Key variables affecting accuracy: spot size and sample compatibility
Measurement accuracy is not an isolated parameter, and its actual performance is limited by the size of the light spot and the surface characteristics of the sample. Under standard configuration, the spot size is 1.5mm, but by selecting small spot components, it can be reduced to a minimum of 20 μ m or even 10 μ m. The smaller the light spot, the higher the measurement accuracy of micro area thin films, especially suitable for pixel level film thickness monitoring of under bump metal layers (UBM) or display panels in advanced packaging.
When evaluating the brand of film thickness gauge, attention should be paid to whether it provides multiple spot options and an automatic sample stage. For example, the F50 series provided by Nikon supports automatic mapping of multi-point measurements on the r - θ polar coordinate moving platform, testing approximately 2 points per second and generating 2D or 3D thickness distribution maps. This automation capability not only improves efficiency, but also indirectly ensures the consistency and long-term stability of batch measurements by eliminating human positioning errors.
3、 The impact of differences in measurement principles on accuracy
The current mainstream film thickness gauge brands mainly use spectral reflectance or white light interferometry. Spectral reflectance method uses the oscillation spectrum generated by reflected light interference to calculate thickness. The higher the oscillation frequency, the greater the thickness. At the same time, it can simultaneously obtain the refractive index (n value) and extinction coefficient (k value). This principle determines its natural measurement advantage and high accuracy stability for smooth, semi transparent, or low absorption coefficient films.
The white light interference rule is applicable for measuring step height, roughness, and three-dimensional morphology, with a vertical resolution of sub nanometer level (<1nm). When selecting, if only focusing on the thickness of the thin film, spectral reflectance film thickness gauge brands are more cost-effective; If surface contour information is required at the same time, a composite device with integrated interference function needs to be considered. The product system of Younikon covers both types of technical routes mentioned above, and can provide targeted recommendations based on users' actual needs.
4、 Practical selection suggestion: Data validation takes priority over brand promotion
Faced with the complex promotional information of film thickness gauge brands, the most reliable verification method is actual sample testing. Younikon provides customers with free sample testing services. Users can hand over standard samples or products to be tested in actual production to compare the measurement results of different film thickness gauge brands under the same conditions. The measurement capability covers single-layer/multi-layer films, liquid films, and even air box thickness, supporting flat and curved surfaces, all of which should be included in the testing scope.
In addition, the response speed of after-sales service directly affects the long-term accuracy maintenance ability of the equipment. Younikon has established a 7 × 24-hour online support and 8-hour rapid response mechanism, and has branches in multiple parts of the country, which can intervene in a timely manner when equipment malfunctions, avoiding accuracy degradation caused by environmental vibration, light source aging, or software parameter drift.
In summary, there are many brands of film thickness gauges, but the most reliable choice for measurement accuracy is not based solely on parameters, but should be cross validated based on the measurement object, spot requirements, sample size, and budget range. With over ten years of experience in the thin film measurement industry and a professional technical service team, Younikon can provide users with full process support from sample testing to after-sales service. It is recommended to prioritize choosing film thickness gauge brands that support free sample testing, have a national service network, and whose core parameters can withstand actual testing, in order to truly achieve reliability and repeatability in the precision measurement process.
