Mountain View, CA--June 17, 1996--A system that performsrapid, highly sensitive inspection of unpatterned 300mm wafershas been announced by Tencor Instruments (Mountain View, CA). The system'scapability is critical to the development of emerging 0.25-micronprocess technologies. Called the Surfscan SP1, it uses arotating-wafer method combined with a stationary illuminationbeam, uniform axi-symmetric collection optics, and an optionalbright-field channel to detect surface defects and contaminantson as many as 100 300mm wafers per hour, or 150 wafersper hour when processing 200mm wafers.
The semiconductor industry's development of devices with minimumfeature sizes of less than 0.25 micron is forcing dramaticallytightened design tolerances. At the same time, productivityrequirements are driving the development of larger, 300mm wafers,on which many of these devices will be manufactured. These dualtechnology trends have created demand for an inspection systemthat can reliably and repeatably detect anomalies as small as0.08 micron while still maintaining high throughput on theselarge wafers.
The Surfscan SP1 is the first wafer inspection systemspecifically designed to meet these criteria. During inspection,the SP1's proprietary technology rotates the wafer and moves italong a radius while the laser beam remains stationary. Combinedwith uniform axi-symmetric collection optics, this enablesscattered light to be collected independent of the defectorientation on the wafer. This capability yields greatermeasurement uniformity and superior sensitivity, allowingdetection of particles and other contaminants down to 0.08 micronat a high capture rate. In addition, the SP1 can accuratelydetect and measure haze (a characteristic closely associated withsurface roughness) down to several parts per billion, a notableincrease in capability over previous unpatterned inspectionsystems.
The Surfscan SP1 is optimized to meet the distinctiverequirements of wafer and equipment manufacturers who demandtechnology and throughput capabilities that currently availableinspection systems do not offer.
With its multiple dark-field collection optics and optionalbright field channel based on Nomarski phase contrast technology,the SP1 can provide an unprecedented amount of surfaceinformation in a single wafer pass. This increases productivityby lowering the number of inspection steps.
Use of the bright-field channel also enables detection ofadditional irregularities, and will allow classification ofdefects such as scratches, slip lines, and stacking faults -- acritical capability for wafer manufacturers.
Lisa Gillette (MCA, Inc.)
Tencor Instruments Inc.
Mountain View, CA
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