1. Chapter 03 Dual-Fluid Spray Cleaning Technique for Particle Removal 1Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.

2. FIGURE 3.1 Cleaning process window depicting particle adhesion force distribution (left) compared with structural integrity force (right) with optimized cleaning forces located in between. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.2

3. FIGURE 3.2 Droplet jet and ultrasonic (US) shock wave forces exceeding van der Waals particle attachment force. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.3

4. FIGURE 3.3 Comparison of the shock wave drag force necessary to remove all particles with the structural strengths of bulk and deposited structures. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.4

5. FIGURE 3.4 Test structures of amorphous-Si on SION (a) and polysilicon on SiO 2 (b) surfaces for AFM measurements. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.5

6. FIGURE 3.5 Cleaning process window showing less energy required to remove particles vs damage structures. Figure provided courtesy of Tae-Gon Kim and used with permission. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.6

7. FIGURE 3.6 Examples of spray cleaning nozzles. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.7

8. FIGURE 3.7 (a) Liquid drop impact on solid surface showing formation of a shock front. (b) Close-up view moments after impact and start of sideways liquid jetting. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.8

9. FIGURE 3.8 Photograph of crown resulting from droplet impact on liquid surface. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.9

10. FIGURE 3.9 Droplet impact on liquid layer showing propagation of shock waves. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.10

11. FIGURE 3.10 Pressure curves (in bar) from shock wave formed from droplet impact on a surface coated with a 10 µm liquid film at different velocities with different droplet diameters. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.11

12. FIGURE 3.11 Dynamic pressure curves (in bar) formed from droplet impact on a surface coated with a 10 µm liquid film at different velocities and droplet diameters. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.12

13. FIGURE 3.12 Averaged PRE for removal of silicon nitride particles for various fluids dispensed through Soft Spray nozzle. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.13

14. FIGURE 3.13 Droplet size and velocity distribution from atomized liquid spray with gas flow rate of 25 L/min. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.14

15. FIGURE 3.14 Schematic drawings of Nanospray (a) and Soft Spray (b) nozzles. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.15

16. FIGURE 3.15 (a) Effect of nitrogen flow on droplet size for Soft Spray and Nanospray nozzles. (b) Droplet size distribution for Soft Spray and Nanospray nozzles at 80 L/min nitrogen flow. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.16

17. FIGURE 3.16 Effect of N 2 flow on PRE and typical damage to 70 nm poly lines using Nanospray (a). Example of typical damage to 70 nm poly line (b). James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.17

18. FIGURE 3.17 High-speed camera images of droplets from Nanospray2 (a) and NanosprayÅ (b) nozzles. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.18

19. FIGURE 3.18 Droplet size (a) and velocity distributions (b) for Nanospray2 and NanosprayÅ. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.19

20. FIGURE 3.19 Damage to photoresist structures for two droplet sizes at varying velocity. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.20

21. FIGURE 3.20 Correlation of droplet energy density with number of damage sites. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.21

22. FIGURE 3.21 Threshold energy curve separating damage-free from damage-potential zone. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.22

23. FIGURE 3.22 Damage threshold curve with Nanospray2 droplets. Below the threshold curve is a damage-free zone and above the curve is the damage-potential zone. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.23

24. FIGURE 3.23 Relationship between droplet velocity and number of removed 78 nm SiO 2 particles. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.24

25. FIGURE 3.24 Relationship between droplet energy density and PRE. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.25

26. FIGURE 3.25 Threshold curves for particle removal and pattern damage generation with dual-fluid Nanospray2 and NanosprayÅ nozzles. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.26

27. FIGURE 3.26 The PRE performance of Nanospray2 and NanosprayÅ nozzles for removal of PSL spheres. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.27

28. FIGURE 3.27 PRE results from removal of PSL spheres using conventional dual-fluid spray cleaning and frozen water. James T. Snow, Masanobu Sato, Takayoshi Tanaka Chapter 3 - Dual-Fluid Spray Cleaning Technique for Particle Removal Developments in Surface Contamination and Cleaning - Methods of Cleaning and Cleanliness Verification. Pages 107 – 138 http://dx.doi.org/10.1016/B978-1-4377-7879-3.00003-0 Copyright owned by James T. Snow, Masanobu Sato, and Takayoshi Tanaka.28