1. 1 Presentation of Super Bubbler3 -Proposal for applying Super Bubbler3 to Hard Disk manufacturing process- Nomura Micro Science Co., Ltd.

2. 2 What kind of problem occurred? -on the Rinsing Process of Hard Disk- n Recent trend: Using ultra pure water for rinse of Hard Disks. n Reason of using UPW: Sharp progress of Hard Disk storage density. n Problem: Decrease of product yields. n Exam.: ‘98- 7G Bits/inch 2, 10,000M Bytes/3.5”, 0.1  m 2 /cell.

3. 3 Reason for occurrence of problems at the process of using UPW. n Electrostatic charge occurs easily by high pressure rinsing etc. because of high resistance of UPW / 18.24Mohm cm. n High voltage electrostatic charge causes various harmful effects. n Ultra pure water dissolves light metals like Al by its strong dissolving power. *UPW destroys O 2 Passivity by hard activity.

4. 4 Harmful effects by electrostatic charge? n A. Breakage of devices: Device destruction effects by discharge of built up high potential static electricity. n B. Electrostatic attraction: Wafers stick the metallic shavings hard to its surfaces by the electrostatic attraction.

5. 5 How to solve? n Best way: To change the ultra pure water to be conductive by re-ionization without de-grading of UPW. n Method of re-ionization: Injection of high purity CO 2 gas by accurate CO 2 injection control. n Results: No electrostatic charge in UPW.

6. 6 Problem of CO 2 injection? -No problem- n A. No residual matter on devices after drying process because of CO 2 re- vaporizing. n B. CO 2 gas is safe for health and economical, also safe for devices.

7. 7 Strong merits of CO 2 water? n CO 2 dissolved water is best for rinsing of light metals like Al because of weak acid character. n CO 2 dissolved water does not dissolve Al because it protects the passivity of Al. n *Exam. of CO 2 water.: Resistivity 0.7-0.3Mohm cm=PH 5.4-4.9

8. 8 Dissolving and ionizing process of CO 2 gas. n CO 2 gas dissolves in water and dissociated, ionized. n H 2 O + CO 2  H 2 CO 3 (1) n H 2 CO 3  H + + HCO 3 - (2) n HCO 3 -  H + + CO 3 2- (3) n (2) H + and HCO 3 2- effective to reduce resistance of water.

9. 9 Standard resistivity? n STD resist. : 0.7-0.2Mohm cm at 25deg.C n pH of STD resist. range: pH5.4-4.9 n Resistivity is inversely proportional to CO 2 gas quantity. n pH is proportional to resistivity. n Too high resistivity: Not effective. n Too low resistivity: Too low pH.

10. 10 Requirements for CO 2 Injection System? n 1. High control accuracy. n 2. Quick response. n 3. Economical and Environment-friendly. n 4. Easy operation. n 5. Capacity of high pressure water. n 6. Wide water flow range.

11. 11 Advantages of Super Bubbler3 1. High control accuracy (  1.5) 2. Short response time. 3. Minimum CO 2 consumption, Minimum consumption parts. 4. Only Input of set resistivity for operation. 5. No need for booster pump. 6. Wide controllable range(200-2000L/h)