PWG5™ Wafer Geometry and Nanotopography Metrology System
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PWG5™ Wafer Geometry and Nanotopography Metrology System The PWG5™ patterned wafer geometry metrology platform produces comprehensive wafer warp, bow, dual-sided nanotopography, high-resolution distortion, in-plane displacement and stress measurements for IC manufacturers. Built on the industry-standard WaferSight™ platform, PWG5 incorporates innovative hardware technology and unique features that support patterned wafer applications with repeatable high precision measurements. These measurements support the most extreme wafer warp requirements for R&D and the most cost-effective inline monitoring applications for high volume manufacturing. PWG5 is a single-tool solution for measuring stress-induced wafer shape, wafer shape-induced pattern overlay errors, wafer front and backside nanotopography, and wafer thickness variations. PWG5 enables faster process ramps and higher yields, providing overlay control through process monitoring and data feed forward, lithography focus window control, and inline monitoring for processes such as thin films, etch, CMP and RTP. As the latest-generation PWG system, the PWG5 enables wafer geometry control for both patterned and unpatterned wafers for ≥96 layer 3D NAND devices and ≤1Xnm logic and DRAM design nodes. Compared to previous generation PWG systems, the PWG5 incorporates new hardware technologies and algorithms that enable enhanced capability, including: Industry-best warp dynamic range, up to 1000μm, for inline monitoring and control of wafer warp and stress resulting from advanced 3D NAND deposition processes Spatial resolution of 40μm and high data density for intra-die stress monitoring to counter processinduced overlay variations High throughput for inline measurements that drive process corrections during high volum

Simultaneous measurements of front and back side of wafer With industry-unique vertical wafer hold, PWG5 metrology systems provide full wafer, simultaneous measurement of front and back wafer surfaces without gravitational distortion effects. A single measurement produces the following wafer metrics: Warp and bow In-plane displacement Stress-induced local curvature Wafer thickness and flatness variation Front and back surface Nanotopography (NT) Wafer edge roll-off (ERO) Industry-unique vertical wafer hold minimizes gravitational distortion Many IC process steps can cause wafer warp, bow,...

PWG5 is part of a comprehensive portfolio of metrology and data analytic products that help IC manufacturers maintain tight control of their processes for improved device performance and yield. The PWG5 metrology system outputs measurement results to the fab’s host as well as to KLA’s 5D Analyzer ® advanced data analysis and patterning control software. Using this information, lithography engineers can understand whether shape-induced overlay can be compensated for by adding additional overlay corrections, including corrections to existing APC (Advanced Process Control). Shape overlay...

PWG5 Applications The PWG5 metrology system can be used to qualify, monitor and control processes in both feedback and feed forward modes. Proven metrics enable faster root cause determination, helping fabs reduce process development time. In addition, the PWG5 offers multiple applications that help expand overlay and focus process windows for ≥96 layer 3D NAND device fabrication, and advanced logic and DRAM design nodes. Correction of wafer shape induced overlay error for reduction of wafer-to-wafer and lot-to-lot variability and improvement of final ADI on-product overlay Intra-die stress...