Unpatterned Wafer Surface Inspection Systems
The Surfscan® SP5 unpatterned wafer inspection system utilizes enhanced deep ultra-violet (DUV) sensitivity and a throughput up to three times that of its predecessor to reliably detect critical defects and surface quality issues for IC, OEM and substrate manufacturing at the 1Xnm design node. The Surfscan SP5 can provide higher sensitivity on bare wafers and blanket films than that of the previous-generation Surfscan SP3. Alternatively, the Surfscan SP5 can operate at a sensitivity similar to that of the Surfscan SP3, but at much higher throughput, enabling increased sampling for a lower cost of ownership. The tool also includes an integrated, high resolution SURFmonitor module that characterizes and measures surface quality, helping IC modules qualify their process and tools by characterizing wafer surface quality and detecting subtle defects.
Integrated SURFmonitor is a defect/metrology module that utilizes background scattering (haze) data from Surfscan SP5 scans to monitor process signatures and low contrast defects, without affecting inspection throughput. SURFmonitor can correlate haze to process parameters such as surface roughness and grain size, serving as a high speed, full-wafer metrology proxy for bare wafers and blanket films.
Process Tool Monitoring: Within the IC fab, the Surfscan SP5 is used for qualification and monitoring of process tools for the 1Xnm design node. The enhanced DUV sensitivity captures tiny blanket film defects at production speeds, enabling engineers to monitor process tools for defects that may be introduced during film deposition or CMP. In addition, the Surfscan SP5’s tolerance to wafer roughness provides improved sensitivity performance on re-claim wafers, allowing fabs to re-use the wafers more times for significant reclaim wafer cost savings.
Lithography: With its unique DUV sensitivity, the Surfscan SP5 detects defocus, resist streak and other critical issues when serving as a lithography process tool monitor. The Surfscan SP5 has unique incident laser power management schemes for operating at optimal levels that produce maximum sensitivity while protecting lithography film materials. The Surfscan SP5’s integrated SURFmonitor module also helps engineers qualify immersion scanners by detecting immersion-unique defects such as water marks.
Incoming Wafer Qualification: The extended DUV sensitivity of the Surfscan SP5 helps IC manufacturers ensure that incoming wafers meet their strict quality specifications.
Process tool qualification: Defects added by the tool during processing, such as fall-on particles or metal contamination, can adversely affect wafer yield or device performance. Certain process steps like polishing can worsen the wafer surface quality and create anomalous process defect signatures that may render the wafer unsuitable for further processing. Early detection and classification of these subtle conditions is critical to ensure optimal yield. The Surfscan SP5’s DUV defect maps and high-resolution DUV SURFimages provide key information, enabling equipment vendors to build reliable, production-worthy process tools.
Process uniformity monitor: The full-wafer high-resolution SURFimage represents the variations of the wafer surface quality in response to changes in process chemistries or recipes, enabling process optimization and production monitoring. Dark field haze calibration ensures that the haze readings are accurate and repeatable across tools.
For information on Surfscan systems available for substrate manufacturing, please see: Surfscan Series - Wafer Manufacturing
For other unpatterned wafer defect inspection tools, please see K-T Certified.