Product Briefing Outline: Tordivel Solar introduce a new generation of optical contamination inspection solutions for mono and poly-crystalline wafers. The Wafer Surface Instrument (WSI) performs an automatic surface quality control of wafers, which can be characterized based on cosmetic surface effects: large area contamination, small area contamination, lines and spots, dark spots, suction cup marks and shiny patches.
Problem: The increased focus on cosmetic surface effects like wafer contamination is due to the higher awareness to quality and is one of the most significant contributors to wafer returns. The Tordivel Solar instrument for contamination detection is a very cost effective measure to reduce wafer returns due to surface effects.
Solution: The system is using a combination of angled lighting and omnidirectional uniform illumination together with two line scan cameras per side and a PC for image collection, processing, user interface and process interface software. The special lighting removes crystals in the image and the cosmetic surface effects like contamination and shiny patches are clearly visible on the wafer image. The 4 MPixel images are captured using line-scan cameras with 80 micrometer resolution. Combining the high-quality images with state of the art image processing algorithms ensures higher sensitivity and selectivity. All the data from the different inspections is fed to the central data processing unit of the Surface Inspection instrument, the Surface Inspection Master. Based on a set of configurable and predefined rules, the information is screened. The information needed as input to the overall classification matrix is transferred by the in Surface Inspection Master to the Wafer Inspection System Master (WISM). In a line configuration, the WISM classify the characterized wafers based quality class specifications and communicate the result to the sorter.
Applications: Mono and poly-crystalline wafers.
Platform: The system is sold as a stand-alone system, as part of the Surface Instrument or as part of the Tordivel Solar WIS – Wafer Inspection System. The characterization instrument is delivered as a one-sided or a two-sided version. The throughput is typically one wafer per second.
Availability: June 2010 onwards.