Surf-Cal, Particle Size Standards, 50ml Volume, Pre-Mixed to 1x10E8 and 1x10E10 Concentration / ml

SURF-CAL™ Particle Size Standards used in size calibration and monitoring of Scanning Surface Inspection Systems (SSIS). Particle sizes below correspond to the calibration particle sizes required by instrument manufacturers. You should complete periodic calibration checks and weekly size and count monitoring to ensure your wafer inspection scanner compares with scanners at other locations. All polystyrene microspheres are suspended in deionized, filtered water in 50mL bottle volume at a concentration of 3 × 10 E8 or 1 × 10 E10 particles per mL. Sizes noted with * are similar to NIST SRM particles at that diameter. Refractive Index is 1.59 @ 589nm (25C) for all polystyrene microspheres below. Each bottle is stable for 12 months and is packaged with a Certificate of Calibration and Traceability to NIST.

By depositing SURF-CAL, NIST traceable PSL (polystyrene latex) spheres on bare silicon and pattern wafers, you can perform periodic size calibration checks on your KLA-Tencor, Hitachi, ADE, Topcon SSIS tools and compare your wafer inspection scanner with scanners at other locations. You can also assess the performance of your SSIS at critical stages in the manufacturing process. All products are suspended in deionized, filtered water (DI water) in 50 mL bottles at a concentration of 3 x10 e10 particles/mL or 1 x10 e10 particles/mL. These Surf-Cal particle size standards are polystyrene microspheres that have been sized by Differential Mobility Analyzer (DMA) or other size exclusionary techniques.

Measurement Methodology:

To assure NIST traceability, the certified diameters of these products were transferred by transmission electron or optical microscopy from NIST standard reference materials (2). The uncertainty was calculated using NIST Technical Note 1297, 1994 Edition "Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results" (4). The uncertainty listed is the expanded uncertainty with a coverage factor of two (K=2). The peak diameter was calculated using approximately the ± 2s range of the particle size distribution. The size distribution was calculated as the standard deviation (SDS) of the whole peak. The Coefficient of Variation (CV) is one standard deviation expressed as a percentage of the peak diameter. The FWHM (full width at Half Maximum) distribution was calculated as the distribution at half of the peak height expressed as a percentage of the peak diameter.

1. "The National Technology Roadmap for Semiconductors", Semiconductor Industry Association (1999)

2. S.D. Duke and E.B. Layendecker, "Internal Standard Method for Size Calibration of Sub-Micron Spherical Particles by Electron Microscopy", Fine Particle Society (1988)

3. SEMI M52 — Guide for Specifying Surface Inspection Systems for Silicon Wafers the 130 nm Technology Generation.

4. Barry N. Taylor and Chris E. Kuyatt, "Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results". NIST Technical Note 1297, 1994 edition, September 1994.