Examination of ion beam induced damage on polymer surface using Ar clusters Tomoko Kawashima, a * Hiromi Morita, b Noriaki Fukumoto, c Takako Kurosawa b and Satoka Aoyagi d The damage of polymer surfaces caused by the high energy primary ion beams of TOF-SIMS was examined using Ar cluster ions. Polymer damage, the damage of secondary ions detected from the polystyrene surface and the damage layer formed by the Bi 3 primary ion beam have previously been studied. In this study, the damage observed in the secondary ions was studied by using Ar cluster primary ions. The secondary ions were mainly classified into two types, ions reflecting the polystyrene structure and cyclized ions, generated by excessive energy, which are not useful for qualitative analysis. The layer damaged by irradiation of the Bi 3 primary ion regarding PS samples was confirmed using Ar cluster sputtering beams. The depth of the layer that has chemical damage in the PS main chain caused by 30kV Bi 3 ++ (ion dose: 5 × 10 12 ions/cm 2 ) irradiation was approximately 50–60nm. The Ar cluster ion sputter rate in PS decreases with the Bi 3 ion irradiation. Micro PS particles that are not able to be detected by a conventional TOF-SIMS measurement can be effectively analyzed by accumulating the secondary ions over the static limit using Ar cluster sputtering. Copyright © 2016 John Wiley & Sons, Ltd. Keywords: TOF-SIMS; Ar clusters; polymer; damage Introduction Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is a powerful tool for analyzing organic contamination in materials and devices without sample pretreatment. There is a need for analysis of small organic materials due to progressed miniaturiza- tion of devices. Recently, methods enabling low damage analysis for organic materials using Ar cluster ions as a sputtering gun or a primary ion beam have been developed. So, detailed analysis of the organic materials can be performed by using an Ar cluster ion beam. However, the lateral resolution of Ar clusters is low. There- fore, the Bi 3 primary ion beam, having high lateral resolution and high sensitivity for organic samples, is still used for analysis of micro polymers. It is often difficult to identify materials in organic samples, especially micro ones, using a Bi 3 primary ion beam, because dam- age and high fragmentation caused by high energy make TOF-SIMS spectra complicated, and also the intensity of important secondary ions is not high enough because of the static limit. In this study, the damage to the polystyrene, [1] caused by the high energy primary ion irradiation was investigated. Fragment ions produced by ion damage were examined by using Ar cluster primary ions for qualitative analysis. Furthermore, the thickness of the damaged layer and change of the sputtering rate were studied using an Ar cluster sputtering beam. Finally, the analysis of a micro polymer by a combination of Bi 3 primary ion analysis and Ar cluster ion beam sputtering is introduced. Experimental Polystyrene (PS) samples of five different molecular weights (Shodex, Showa Denko America, Inc., NY), S1.2 (peak molecular weight, Mp:1200 u), S1.7 (Mp:1650 u), S13 (Mp:12700 u), S53 (Mp:535000 u), and S809 (Mp: 809000 u) and poly (alpha- methylstyrene) (PMS) of two different molecular weights (Polymer Source, Inc., Canada, Mp:1900 u and Scientific Polymer Products, Inc, NY, Mp:5000 u) were analyzed. The xylene solution of each polymer was spin-coated on a Si wafer. TOF-SIMS analysis was performed with TOF.SIMS 5 (ION-TOF GmbH, Germany) with 30 kV Bi 3 ++ (20 keV/atom), 5 kV Ar 1000 + (5 eV/ atom), 7.5 kV Ar 1000 + (7.5 eV/atom), 10 kV Ar 1000 + (10 eV/atom), 20 kV Ar 1000 + (20 eV/atom) and 20 kV Ar 500 + (40 eV/atom) primary ions. The samples were sputtered using a 5 kV Ar 2500 + (peak top value) beam and analyzed using a 30kV Bi 3 ++ beam (20 keV/atom, ion dose: 4.1 × 10 10 ions/cm 2 ) for depth profiling. The depths of the sputtering areas were measured with a stylus surface profiler P-10 (Tencor Corp., USA). * Correspondence to: T. Kawashima, Appliances Company, Panasonic Corporation, 3-4 Hikaridai, Seika-cho, Soraku-gun, Kyoto, Japan. E-mail: hosokawa.tomoko@jp.panasonic.com a Appliances Company, Panasonic Corporation, 3-4 Hikaridai, Seika-cho, Soraku- gun, Kyoto, Japan b Advanced Research Division, Panasonic Corporation, 3-1-1 Yagumo-naka-machi, Moriguchi-shi, Osaka, Japan c Eco Solutions Company, Panasonic Corporation, 1048 Oazakadoma, Kadoma- shi, Osaka, Japan d Department of Materials and Life Science, Seikei University, 3-3-1 Kichijoji- kitamachi, Musashino-shi, Tokyo, Japan Surf. Interface Anal. 2016 Copyright © 2016 John Wiley & Sons, Ltd. Special issue article Received: 1 July 2016 Accepted: 1 July 2016 Published online in Wiley Online Library (wileyonlinelibrary.com) DOI 10.1002/sia.6097