Siltronic evaluating Altatech Semiconductor's wafer-inspection system

MONTBONNOT, FRANCE: Siltronic AG, one of the leading suppliers of silicon wafers, is evaluating an AltaSight SL300 inspection system from Altatech Semiconductor S.A. to verify the tool's capabilities for use in wafer manufacturing.

The 300 mm system's combined capabilities in reflectivity, topographical and dark-field inspection as well as its 100-wafers-per-hour throughput and reliability in a cleanroom environment are being tested at Siltronic's facility in Burghausen, Germany.

AltaSight's system architecture incorporates several different inspection technologies, which are used in combination to precisely identify, locate and classify a wide range of defects on semiconductor wafers. Altatech's patented phase-shift illumination technology generates topographical maps with nanometer resolution.

In addition, a global light-absorption analyzer measures the amplitude of multiple wavelengths of light, searching for any non-topographical defects. Ultrafast dark-field technology is used to inspect each wafer's surfaces for particles and scratches, while Altatech's patented EyeEdge optical sensors identify defects along a wafer's edge.

The data collected from these complementary inspection methods is then compared and analyzed to produce a comprehensive wafer map in less than 25 seconds.

AltaSight's automated defect-classification capabilities are specifically designed to address the needs of silicon wafer suppliers such as Siltronic. The system can detect slip lines inside a wafer's crystalline structure with a vertical sensitivity of 2 nm as well as perform front-side, back-side and edge inspection in one pass. Wafers pass vertically through AltaSight's Class 1 measurement chamber, where full-field optics can detect defects as small as 2 nm.

"Siltronic's close examination of our AltaSight platform's overall performance is a major step toward proving its production-worthiness," said Jean-Luc Delcarri, president of Altatech Semiconductor.

To date, Altatech has installed multiple AltaSight units at customers' facilities worldwide, where they are being used in R&D and pilot-line productions.

"As a leading silicon wafer producer, our manufacturing process also comprises highly sophisticated inspection steps to verify and secure outgoing product quality in order to constantly meet our customers' specific requirements," said Dr. Frank Laube, senior manager, wafer surface inspection at Siltronic. "The high-speed defect-detection and classification technologies offered by Altatech have been shown to be an attractive and powerful new method for wafer inspection."

"We've worked closely with Siltronic to understand all of the requirements for silicon wafer production. In terms of inspection capabilities as well as the silicon wafer manufacturing process flow and cost-of-ownership models, we believe we provide a very attractive solution," Delcarri said.