DPSS Lasers for Semiconductor Inspection and Metrology
What is semiconductor inspection?
Semiconductor inspection is a crucial process during the manufacturing of integrated circuits, often called microchips. It involves using various techniques, often centred around lasers, to meticulously examine semiconductor wafers and other components for any defects or imperfections that could compromise the final product's performance or functionality.
Lasers play a critical role in ensuring the quality and precision of modern semiconductors. These tiny electronic workhorses rely on incredibly small features and structures, and lasers provide the accuracy, control, and non-destructive capabilities needed to inspect and measure them effectively.
Why is Semiconductor Inspection Important?
Microscopic Precision
Modern integrated circuits contain incredibly tiny transistors and features, often measured in nanometers (billionths of a meter). Even a single defect can disrupt the delicate electrical pathways within the chip, causing it to malfunction.
Yield Management
The fabrication process for semiconductors involves hundreds of steps. Early detection of defects prevents wasted effort on processing faulty wafers further down the line, improving overall production yield.
Quality and Reliability
Semiconductor devices power everything from smartphones to medical equipment. Thorough inspection ensures the final product meets stringent quality standards and functions reliably.
Key Properties of Lasers for Semiconductor Applications
Single Frequency
Semiconductor features are microscopic, so lasers with a very precise, single wavelength are crucial. This ensures sharp focus and minimises errors during measurements.
High Stability
Consistent output power and minimal fluctuations in wavelength are essential for reliable and repeatable measurements.
Controllable Power
The ability to precisely control the laser's intensity allows for fine-tuned interaction with the semiconductor material.
Laser Applications in Semiconductor Inspection and Metrology
Lasers excite the semiconductor material with light, causing it to emit its own light (photoluminescence). This emitted light reveals information about the material's properties and defects. Variations in the emitted light can indicate impurities, strain, or other issues
Lasers are used in various interferometric techniques to precisely measure the dimensions of semiconductor features. By splitting a laser beam and analyzing the interaction of the separated beams after they interact with the sample, minute variations in height or thickness can be measured with extreme accuracy.
Optical Critical Dimension (OCD) Metrology
This technique uses lasers to measure the critical dimensions (width, height) of features on a semiconductor wafer. Accurate OCD metrology is essential for ensuring the proper functioning of the final electronic device.
Surface Roughness Measurement
Lasers can be used to analyze the surface roughness of semiconductor materials. Even slight variations in surface smoothness can impact device performance.
Skylark Lasers are specifically designed for semiconductor inspection
The Skylark NX lasers offer ultra-stable, high power, single frequency laser sources that stand out for their exceptional wavelength stability, narrow linewidth, and long coherence length. Ideal for a broad range of semiconductor material and structure analysis applications as well as select wafer inspection techniques:
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Wafer metrology
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Wafer defect detection
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Thin film metrology
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Semiconductor material analysis
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Photoluminescence spectroscopy
For semiconductor inspection applications, our ultraviolet lasers at 320 and 349 nm are ideal.
