Why Are Silicon Wafers as Thick as They Are?


March 10, 2023

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As a rule, the material where you use the silicon wafer will determine the thickness you need for your research. Generally, Si wafers have a thickness between 0.5mm and 400 microns (0.4mm). Thin wafers between 2 and 25 microns in thickness can be needed for some scientific purposes. While silicon wafers vary in size, why are some as thick as they are? Here are some facts about Si wafers that will help you learn.

An Si Wafer on top of what it seems a notebook with notes

Silicon Wafer Sizes

Expansion of Wafer Sizes

For more than 40 years, silicon wafers have served as the foundation of the electronics sector. Wafer sizes expanded from 2 inches in diameter in 1970 to 300 millimeters in 2000, greatly boosting chip production productivity. Wafer thickness continuously grew with increasing diameters, peaking at 775 m for wafers with a 300 mm diameter.  

The main driver behind this growth was the necessity to enable safe wafer manufacture without breakage. It was also to offer enough mechanical and thermal stability of the wafers in IC fabrication during the processing steps of lithography and heat treatments. In addition, silicon wafers must satisfy specific defect kinetic parameters during device production, which also depend on wafer thickness. This is essential for device yield and viability from an economic standpoint.

Silicon Wafer Thickness Measurement Using Lasers

The silicon wafer could be utilized as the standard sample for device calibration, according to research showing extremely accurate thickness distributions on the wafer. NIST is creating a new calibration method that precisely measures the thickness of silicon wafers 300 millimeters thick using infrared laser light. To evaluate surface forms from either side of the sample and define thickness, the approach uses light that reflects exclusively from the front surface of the sample.

Close up of an Si Wafer under a miscroscope

Are You Interested in Getting Si Wafers?

At Wafer World, our team can provide high-quality silicon wafers, germanium, and other materials to help your business grow. Give us a call to learn more about the products we offer!