Surface Contamination and Cleaning, Volume 1 K.L. Mittal, Editor VSP Surface Contamination and Cleaning, Volume 1 This page intentionally left blank S URFACE C ONTAMINATION C AND LEANING VOLUME 1 Editor: K.L. Mittal UTRECHT (cid:1) BOSTON 2003 VSP BV Tel: +31 30 692 5790 P.O. Box 346 Fax: +31 30 693 2081 3700 AH Zeist [email protected] The Netherlands www.vsppub.com © VSP BV 2003 First published in 2003 ISBN 90-6764-376-9 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopy- ing, recording or otherwise, without the prior permission of the copyright owner. Printed in The Netherlands by Ridderprint bv, Ridderkerk Contents Preface vii Mapping of surface contaminants by tunable infrared-laser imaging D. Ottesen, S. Sickafoose, H. Johnsen, T. Kulp, K. Armstrong, S. Allendorf and T. Hoffard 1 Monitoring cleanliness and defining acceptable cleanliness levels M.K. Chawla 23 Tracking surface ionic contamination by ion chromatography B. Newton 43 A new method using MESERAN technique for measuring surface contamination after solvent extraction M.G. Benkovich and J.L. Anderson 49 Methods for pharmaceutical cleaning validations H.J. Kaiser 75 Influence of cleaning on the surface of model glasses and their sensitivity to organic contamination W. Birch, S. Mechken and A. Carré 85 Decontamination of sensitive equipment R. Kaiser and K. Haraldsen 109 The fundamentals of no-chemistry process cleaning J.B. Durkee II 129 Development of a technology for generation of ice particles D.V. Shishkin, E.S. Geskin and B. Goldenberg 137 Cleaning with solid carbon dioxide pellet blasting F.C. Young 151 Development of a generic procedure for modeling of waterjet cleaning K. Babets and E.S. Geskin 159 vi Contents Experimental and numerical investigation of waterjet derusting technology K. Babets, E.S. Geskin and B. Goldenberg 173 Practical applications of icejet technology in surface processing D.V. Shishkin, E.S. Geskin and B. Goldenberg 193 Correlating cleanliness to electrical performance T. Munson 213 Qualifying a cleaning system for space flight printed wiring assemblies J.K. “Kirk” Bonner and A. Mehta 225 Investigation of modified SC-1 solutions for silicon wafer cleaning C. Beaudry and S. Verhaverbeke 241 Performance qualification of post-CMP cleaning equipment in a semiconductor fabrication environment M.T. Andreas 249 Spatial and temporal scales in wet processing of deep submicrometer features M. Olim 261 Microdenier fabrics for cleanroom wipers J. Skoufis and D.W. Cooper 267 Fine particle detachment studied by reflectometry and atomic force microscopy A. Feiler and J. Ralston 279 Dust removal from solar panels and spacecraft on Mars S. Trigwell, M.K. Mazumder, A.S. Biris, S. Anderson and C.U. Yurteri 293 Laser cleaning of silicon wafers: Prospects and problems M. Mosbacher, V. Dobler, M. Bertsch, H.-J. Münzer, J. Boneberg and P. Leiderer 311 Particle removal using resonant laser detachment K. Kearney and P. Hammond 335 The future of industrial cleaning and related public policy-making C. LeBlanc 345 Surface Contamination and Cleaning, Vol. 1, pp. vii–viii Ed. K.L. Mittal © VSP 2003 Preface This volume chronicles the proceedings of the International Symposium on Sur- fase Contamination and Cleaning held under the aegis of MST Conferences in Newark, New Jersey, May 23–25, 2001. Even a cursory look at the literature will evince that there has been tremendous interest and R&D activity in the arena of surface contamination and cleaning, so we decided to organize this symposium. Because of the importance of this topic in many technological areas, tremendous efforts have been devoted to devise novel and more efficient ways to monitor, analyse and characterize contamination on surfaces as well as ways to remove such contamination from a wide variety of surfaces. The ubiquitous nature of surface contamination causes concern to everyone dealing with surfaces, and the world of surfaces is wide and open-ended. A con- taminant is defined as “unwanted matter or energy” or “material or energy in the wrong place”. Also contaminants can by broadly classified as: film-type, particu- lates; ionic, and biological or microbial. The technological areas where surface contamination has always been a bete noire and thus surface cleaning is of cardi- nal importance are too many and range from aerospace to microelectronics to biomedical. Here a few eclectic examples will suffice to underscore the impor- tance of surface contamination and cleaning. In the world of ever-shrinking de- vice dimensions in the microelectronics, the need to remove ever smaller particles (of nanosize dimension) is quite patent. On the other hand, film-type (organic) contamination is of crucial importance in the area of adhesive bonding, as even a very thin layer of contamination can be very detrimental in attaining good bond strength. In operation theaters, the concern about microbial contamination is all too obvious. So in light of the great concern about surface contamination, people dealing with surfaces are rightfully afflicted with molysmophobia.* The technical program for this symposium comprised 45 papers dealing with all kinds of contaminations on a host of surfaces, and many ramifications of sur- face contamination and cleaning were addressed. There were brisk and illuminat- ing (not exothermic) discussions, both formally and informally, throughout the symposium. Also if comments from the participants are a barometer for the suc- cess of a symposium then this event was quite successful. Now coming to this volume, it contains a total of 24 papers (others are not in- cluded for a variety of reasons). It must be recorded that all manuscripts were rig- orously peer reviewed and suitably revised (some twice or thrice) before inclusion in this volume. So this volume is not a mere collection of unreviewed papers − viii Preface which is generally the case with many symposia proceedings − rather it reflects information which has passed peer scrutiny. The topics covered include: mapping of surface contaminants; various techniques for cleaning surfaces; various tech- niques for monitoring level of cleanliness; acceptable cleanliness levels, ionic contamination; pharmaceutical cleaning validations; cleaning of glass surfaces; decontamination of sensitive equipment; no-chemistry process cleaning; waterjet cleaning; cleaning with solid carbon dioxide pellet blasting; cleanroom wipers; dust removal from solar panels and spacecraft on Mars; laser cleaning of silicon surfaces; particle removal; implications of surface contamination and cleaning; and future of industrial cleaning and related public policy-making. I sincerely hope that this volume addressing many aspects and recent develop- ments in the domain of surface contamination and cleaning will be of interest to a wide range of people working in many different industries. Acknowledgements It is always a pleasure to write this particular segment of a book as it offers the opportunity to thank those who helped in many ways. First, my sincere thanks are extended to my colleague and friend, Dr. Robert H. Lacombe, for taking care of the organizational aspects of this symposium. The comments from the peers are a sine qua non to maintain the highest standard of a publication, so I am most ap- preciative of the time and efforts of the unsung heroes (reviewers) in providing many valuable comments. I am profusely thankful to the authors for their interest, enthusiasm and contribution without which this book would not have seen the light of day. In closing, my thanks go to the staff of VSP (publisher) for giving this book a body form. K.L. Mittal P.O. Box 1280 Hopewell Jct., NY 12533 *Molysmophobia means fear of dirt or contamination, from Mrs. Byrne’s Dictionary of Unusual, Obscure, and Preposterous Words, University Books, Secaucus, NJ (1974). Surface Contamination and Cleaning, Vol. 1, pp. 1–22 Ed. K.L. Mittal © VSP 2003 Mapping of surface contaminants by tunable infrared-laser imaging ∗ DAVID OTTESEN, SHANE SICKAFOOSE, HOWARD JOHNSEN, TOM KULP, KARLA ARMSTRONG, SARAH ALLENDORF and 1 THERESA HOFFARD Sandia National Laboratories, P.O. Box 969, MS 9403, Livermore, CA 94551-0969 1Naval Facilities Engineering Service Center, 1100 23rd Avenue, Port Hueneme, CA 93043-4370 Abstract—We report the development of a new, real-time non-contacting monitor for cleanliness verification based on tunable infrared-laser methods. New analytical capabilities are required to maximize the efficiency of cleaning operations at a variety of federal (Department of Defense [DoD] and Department of Energy [DOE]) and industrial facilities. These methods will lead to a re- duction in the generation of waste streams while improving the quality of subsequent processes and the long-term reliability of manufactured, repaired or refurbished parts. We have demonstrated the feasibility of tunable infrared-laser imaging for the detection of con- taminant residues common to DoD and DOE components. The approach relies on the technique of infrared reflection spectroscopy for the detection of residues. An optical interface for the laser-imaging method was constructed, and a series of test surfaces was prepared with known amounts of contaminants. Independent calibration of the laser reflectance images was performed with Fourier transform infrared (FTIR) spectroscopy. The performance of both optical techniques was evaluated as a function of several variables, including the amount of contaminant, surface roughness of the panel, and the presence of possible interfering species (such as water). FTIR spectra demonstrated that a water film up to 7 µm thick would not interfere with the effectiveness of the laser-imaging instrument. The instrumental detection limit for the laser reflec- tance imager was determined to be on the order of a 10-20 nm thick film of a general hydrocarbon contaminant. Keywords: Infrared; tunable-laser; imaging; cleaning; surface contamination. 1. INTRODUCTION Real-time techniques to provide both qualitative and quantitative assessments of surface cleanliness are needed for a wide variety of governmental and industrial applications. The range of potential applications include aircraft, shipboard, vehi- cle, and weapon component surfaces to be coated, plated, or bonded. The avail- ∗To whom all correspondence should be addressed. Phone: (925) 294-3526, Fax: (925) 294-3410, E-mail: [email protected]