In semiconductor chip manufacturing, the thickness error of photoresist needs to be controlled within 0.1 nanometers; In the field of perovskite solar cells, the thickness of the functional layer directly affects the photoelectric conversion efficiency; In the aerospace field, the uniformity of composite material coatings is crucial for flight safety, and the common requirements of these scenarios have driven thin film thickness gauges to become precision detection equipment in modern industry. From nano level ultra-thin films to millimeter level thick coatings, thin film thickness gauges have constructed a measurement system covering the entire thickness range through diverse technical paths.

1、 Technical principle: The leap from contact to non-contact

The technological evolution history of thin film thickness gauges is essentially a game between accuracy and efficiency. Early mechanical contact thickness gauges used pressure sensors to contact the surface of thin films and calculated thickness using voltage signals generated by elastic deformation. Their resolution could reach 0.1 micrometers, but they had defects such as scratching the sample and slow measurement speed. Taking the CHY-C2A model as an example, its measurement pressure needs to be accurately controlled at 17.5 ± 1kPa, with a contact area of 50mm ². Although it meets the GB/T 6672 standard, it still shows limitations in the detection of ultra-thin flexible materials.

2、 Application scenario: Full domain penetration from micro to macro

In the field of semiconductor manufacturing, thin film thickness gauges are the "quality gatekeepers" of photolithography processes. In TSMC's 3nm process, each wafer needs to undergo 12 layers of photoresist coating, and the thickness error of each layer needs to be controlled within ± 0.5nm. The Filmetrics KLA series uses spectroscopic ellipsometry technology, which can complete single point measurements within 0.3 seconds, increasing production line yield by 2.3%.

The new energy sector also relies on high-precision thickness measurement technology. The thickness of the amorphous silicon passivation layer directly affects the open circuit voltage in HJT batteries produced by LONGi Green Energy. The Atometics AM series white light interferometer equipped with its detection line can monitor the dynamic changes of 200nm thickness in real time by analyzing the displacement of interference fringes, and compress the standard deviation of film thickness uniformity from 1.2nm to 0.5nm.

3、 Technological Trend: Dual Transformation of Intelligence and Integration

Currently, the thin film thickness gauge is undergoing a transformation from a single detection tool to an intelligent detection system. The 3D measuring instrument launched by Keyence combines purple laser scanning with AI algorithms to simultaneously obtain data on film thickness, surface roughness, and morphology. In flexible circuit board testing, the detection efficiency is increased by 5 times.

The trend towards integration is also significant. The valve island thickness measurement system developed by an enterprise integrates multiple sensors and control modules into a single module. During the reconstruction of the steel caster hydraulic system, the pipeline length was reduced by 70%, the leakage point was reduced by 90%, and the maintenance cycle was extended from once a month to once a half year.

4、 Market pattern: Global competition and technological barriers coexist:

Core algorithms: such as wavelength demodulation algorithm for spectral confocal method and phase extraction algorithm for optical interferometry, which require decades of technical accumulation;

Material database: The refractive index, extinction coefficient, and other parameters of different materials require massive experimental data support;

Environmental adaptability: The adaptive design of industrial scenarios such as high temperature, high pressure, and strong electromagnetic interference poses a major obstacle for new entrants.

From nanoscale chip manufacturing to millimeter scale composite material processing, thin film thickness gauges are measuring every microscopic detail of modern industry with an accuracy step of 0.01 micrometers. With the integration of AI algorithms and quantum sensing technology, this field may usher in a revolutionary change in the next decade, with measurement accuracy exceeding 0.001 microns and detection speed increasing by 100 times, providing key support for cutting-edge industries such as intelligent manufacturing and quantum computing.