A Closer Look at Silicon Wafer Grades


August 16, 2021

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Did you know that the silicon wafer can come in different grades on the basis of quality? When it comes to properties and applications, each grade is unique. Let’s talk about the different types of wafer grades.

Silicone wafer under the microscope

What Are the Different Types of Silicon Wafer Grades?

Prime Wafers

Known as the highest possible grade of a silicon wafer, true prime wafers or device-quality wafers are more expensive compared to other silicon grades. However, these wafers are worth their price because of their exceptional performance, excellent quality, perfectly polished surface, ability to offer tight resistivity specs, and extended lifespan. Some of the applications of prime wafers include particle monitors, semiconductor manufacturing, and photolithography.

Test Wafers

Since most test wafers are wafers that have failed one or more specifications, they have much looser tolerances compare to prime wafers. Moreover, test wafers are less stringent in terms of bulk, physical, and surface properties. Besides having a wider resistivity range, these wafers don’t have specs for flatness and backsides.Test wafers generally work well for processes that aren’t highly sensitive to uniformity. For this reason, they’re often used for testing equipment and semiconductor fabrication control management.

Reclaimed Wafers

The development of silicon wafers with larger diameters caused a spike in the cost of producing wafers. In an attempt to create a cost-effective alternative to standard wafers, manufacturers came up with the wafer reclaim process. When wafers that have been used in a semiconductor manufacturing process are stripped of contaminants, cleaned, and repolished or refinished to a test-grade quality, they become reclaimed wafers.Since reclaimed wafers become thinner with each re-polish, they can only be used up to three or four times. When it comes to resistivity, these wafers are usually sold without tight restrictions.

Silicon Wafer in carriers

Looking for High-Quality Silicon Wafer?

At Wafer World, we offer high-quality silicon wafers at a reasonable price. Contact us to learn more about our products or to request a quote!