Measurement Sensors for the Semiconductor Industry

Modern electronics are getting smaller, more powerful and more energy efficient each year. For example, in 2005 the Intel Pentium 4 670 was a single-core CPU with approximately 169 million transistors on its die. For comparison, the Intel Core i9-11900K (released in 2021) is a 10-core CPU with 10.2 billion transistors.

Due to these miniaturizations, lithography manufacturing demands increasingly higher degrees of precision. Advanced measurement sensors are required to ensure precise wafer alignment, increase traceability, and optimize the manufacturing and inspection processes.

The semiconductor industry relies on complex manufacturing steps, which are accompanied by several inspection processes. KEYENCE’s CL-3000 Series confocal laser displacement sensors feature sub-micron accuracy, and they’re most commonly used to inspect the results of the lapping process as well as the height and uniformity of subsequently added spin coating.

Measuring the groove depth after etching the silicon is crucial to ensure that the etched patterns are of the correct dimensions, and KEYENCE’s WI-5000 Series offers automated groove depth measurement of both mirrored and transparent surfaces while also reducing cycle time, human error, and inconsistent inspection.

Subsequent manufacturing processes in the semiconductor industry include wafer edge profile measurement and finding the wafer notch position for dicing. These inspection steps are typically done with devices such as KEYENCE’s LJ-X8000 Series, which offers 3200 data points per profile.

Precision in the semiconductor industry greatly depends on proper equipment calibration and positioning, which implies occasional inspection and continuous monitoring. KEYENCE’s Spectral-interference laser displacement meter, the SI-F1000 Series, can track stage positioning with a resolution of 1nm without generating any heat that could potentially cause measurement or positioning error.

Wafer cutting is an extremely important process that relies on saw wires mounted on rollers. The pitch of the wires varies with temperature and the form of the main roller, which can affect the quality of the product. The wire pitch can be monitored using the LS-9000 Series, which can detect the changes in wire diameter and, thus, the pitch.

Semiconductors, particularly silicon wafers and exposed dies, are sensitive to physical touch—even a microscopic dust particle can cause defects in the semiconductor wafers—which is why the semiconductor industry relies on non-contact measuring methods.

These methods often rely on laser displacement technology, which can be used to measure distance, thickness, profiles, displacement and deformations, and surface roughness, and they’re used in 3D scanning and imaging. The main benefits of KEYENCE’s products are their accuracy, which is in the µm range—some products go as low as 1 nm—and their non-contact measurement approach.

These sensors ensure the efficiency of the semiconductor manufacturing process, lower cost of production, and the enhanced quality of the overall product.

If you want to learn more about various measurement sensors used in the semiconductor industry, contact KEYENCE. Our trained staff will answer all your inquiries regarding measurement sensors and their integration within your existing manufacturing layout.