1. 1 Copyright © 2011, Elsevier Inc. All rights Reserved. Chapter 3 Methods for Monitoring and Measuring Cleanliness of Surfaces Rajiv Kohli

2. 2 Copyright © 2011, Elsevier Inc. All rights Reserved. FIGURE 3.1 Dust tape test kit. Courtesy of Elcometer, U.K.

3. 3 Copyright © 2011, Elsevier Inc. All rights Reserved. FIGURE 3.2 Contact angle as an indicator of surface cleanliness. The right figure has a low contact angle indicating a clean surface, while the left figure shows a high contact angle on a contaminated surface.

4. 4 Copyright © 2011, Elsevier Inc. All rights Reserved. FIGURE 3.3 Schematic diagram of the DOCC system [82].

5. 5 Copyright © 2011, Elsevier Inc. All rights Reserved. FIGURE 3.4 MESERAN calibration curve for Krytox fluorinated grease on 304 L stainless steel [88].

6. 6 Copyright © 2011, Elsevier Inc. All rights Reserved. FIGURE 3.5 GA-FTIR device on a tripod oriented to analyze the underside of a wing of an A-10 aircraft [105].

7. 7 Copyright © 2011, Elsevier Inc. All rights Reserved. FIGURE 3.6 Integrated circuit in (a) bright field, (b) dark field, and (c) differential interference contrast with reflected light. Courtesy of Nikon, Japan.

8. 8 Copyright © 2011, Elsevier Inc. All rights Reserved. FIGURE 3.7 Appearance of TEM asbestos specimens prepared by direct-transfer (left) and indirect-transfer (right) preparation methods from an air filter collected during abrasion of a gasket. Courtesy of E. Chatfield.

9. 9 Copyright © 2011, Elsevier Inc. All rights Reserved. FIGURE 3.8 Schematic arrangement of a hot-electron microcalorimeter system.

10. 10 Copyright © 2011, Elsevier Inc. All rights Reserved. FIGURE 3.9 Microcalorimeter EDS spectrum of a tungsten particle on a silicon substrate [176]. Courtesy of NIST.

11. 11 Copyright © 2011, Elsevier Inc. All rights Reserved. FIGURE 3.10 Schematic diagram of a plasma chromatography-mass spectrometry system for monitoring cleanliness of surfaces [212].

12. 12 Copyright © 2011, Elsevier Inc. All rights Reserved. FIGURE 3.11 High-sensitivity depth profiling of phosphorus on a silicon substrate. A sputter rate higher than 0.5 μm/min and a detection limit of 5 10 13 at/ cm 3 (1 ppb) were achieved [246].

13. 13 Copyright © 2011, Elsevier Inc. All rights Reserved. FIGURE 3.12 Raman image of polystyrene (PS) beads demonstrates the spatial resolution of the technique at sub-micrometer scale. Courtesy of Horiba, Japan.

14. 14 Copyright © 2011, Elsevier Inc. All rights Reserved. FIGURE 3.13 White contaminant particle found in a factory producing resin identified as a titanium species by micro-XRF, and TiO 2 by Raman microscopy. (a) Optical image. (b) Micro-XRF image. (c) Raman spectrum of the particle and reference TiO 2 spectrum. Courtesy of Horiba, Japan.

15. 15 Copyright © 2011, Elsevier Inc. All rights Reserved. FIGURE 3.14 Micro-CT scan of a used filter from a vacuum cleaner with dust particles. (a) SEM secondary electron image. (b) X-ray image through the sample; (c) 3D rendered front view with the particles shown in red; (d) semi-transparent 3D rendered side view. Courtesy of SKYSCAN, Kontich, Belgium.

16. 16 Copyright © 2011, Elsevier Inc. All rights Reserved. FIGURE 3.15 Hafnium silicate spectrum with Ir–L α source irradiation. The sample was a 2 nm hafnium silicate film intentionally contaminated with 5 × 10 11 atoms of Ti, Cr, Fe, Ni, and Cu [300].