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 micron level 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.

Laser snapshot sensors for the semiconductor industry are used in measurement applications such as the manufacturing of silicon wafers. The sensors can measure the thickness, bow, flatness, notch alignment, and warp of wafers with micron-level accuracy and repeatability. Such precision is crucial in the production of transistors and other miniaturized components.

Apart from dimensional measurement, snapshot sensor solutions help with polishing pad inspections. Using snapshot sensors, manufacturers can scan the surface profile and texture of wafer polishing pads to check for wear and the presence of defects such as cracks, scratches, and foreign particles that can affect the operation of finished products. This allows for timely maintenance and replacement of polishing pads, resulting in improved yield and reduced downtime.

Snapshot sensors also play a crucial role in the die application inspection process. Die application refers to the process of attaching individual semiconductor chips onto a substrate, such as a lead frame. This requires precise and accurate placement of the chip onto the substrate, as well as ensuring that there are no defects in the adhesive used to bond them together.

During die application, snapshot sensors can be utilized to measure the dimensions of the adhesive layer, ensuring that it is within the specified tolerances. They can also detect any bubbles or voids in the adhesive, which can cause delamination and lead to product failure.

3D Laser snapshot sensors for the semiconductor industry play a crucial role in wafer inspection and defect detection. With their high-speed capture capability, they can quickly scan the surface of wafers to identify any defects or abnormalities that may affect the performance of semiconductor devices. This enables manufacturers to catch potential issues early on and take appropriate measures to prevent them from causing major problems down the line.

Identifying many of these defects can’t be achieved with conventional means or through manual inspection. Using 3D laser snapshot systems like the LJ-S8000 Series enables manufacturers to carry out inspections down to micron level accuracy. Accurate inspections help identify components and products with issues, preventing problematic areas from getting to final assembly.

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.

• Semiconductor Wafer Defect Inspection
• Wafer Notch Detection and Measurement
• Lead Frame Inspection and Measurement

Production lines in the semiconductor industry must be well equipped with the right measurement and inspection systems to accurately detect tiny defects or deviations from product tolerances and other inconsistencies.

KEYENCE LJ-S8000 Series comes with standard and advanced functions for accurate 3D measurements and inspections. Unlike other solutions requiring external lighting, a staging device, and an encoder, the LJ-S8000 Series line of laser snapshot sensors feature an internal laser lighting source and scanning mechanism. This means there is no requirement for external head rotation. With imaging as fast as 0.2 seconds and repeatability of 0.3 µm, the sensor product is ideal for rapid and precision-based dimensioning, shape, appearance, and other inspection needs.

Contact KEYENCE today for more information about our laser snapshot sensors for the semiconductor industry. Our trained staff will answer all your inquiries regarding integration within your existing manufacturing layout.