OnWafer Technologies Gets Inside the Process Zone

By Scott Eldredge, Hacienda Network Staff Writer

Company Leads Way in Wafer-Level Yield Enhancement During Semiconductor Fabrication

OnWafer Technologies, which moved into a new 12,000 square foot facility in Hacienda this year, is leading semiconductor production into the next generation with the development of metrology tools that measure what occurs on the surface of a wafer during manufacturing. Yield-enhancing data is collected in real time to enable more precise control and increased productivity. Customers for OnWafer's products include device manufacturers, the companies that produce computer chips, and manufacturers of chip-making capital equipment around the globe.

In the semiconductor industry, the size of chip features is called the critical dimension (CD). Smaller CDs allow the development of faster and more powerful processors and chipsets. Manufacturing yield and cost is determined by the ability to maintain CD accuracy and uniformity, something that has become increasingly difficult as CDs have become smaller. The ability to measure and control manufacturing conditions is a limiting factor. OnWafer Technologies was founded to develop a solution to this problem, and it is succeeding.

Historically, CD control has been accomplished with metrology tools that measure characteristics on the silicon wafers produced. The causes of unwanted variances are inferred from the results, and manufacturing parameters are adjusted - a difficult task because of the complexity of the equipment and the fact that the final result is measured, not characteristics of the process itself. OnWafer solved this problem by embedding on the surface of a standard wafer sensors that actually measure conditions in the production environment - the process zone.

"The primary advantage of OnWafer is that we can measure in situ the processes being used today. We build a precision instrumented wireless sensor network and electronics package onto the surface of the wafer," says Paul MacDonald, director of marketing. "Carefully selected materials allow accurate measurement in a variety of process environments; from highly corrosive plasma processes to the most critical baking processes."

When the SensorWafer is utilized, the sensors record and transmit critical information such as temperature at the wafer surface; a good indicator of the state of the entire process. The data is monitored for conformance to process control specifications and analyzed with a suite of software applications. No changes are required to the manufacturing environment, and the test wafers are reusable, making OnWafer's approach low cost and adaptable to different manufacturing techniques.

OnWafer was founded in 2000 by academia and industry experts. Its first products were in use by 2001, and the company continues to grow both in terms of customers and revenue. The company continues to add to its sensor technology offerings with the internal development of sensors and targeted acquisitions, such as a division of Advanced Energy (Colorado).

Photo: OnWafer Technologies recently moved into this 12,000 square foot facility, which serves as their company headquarters.

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