| AVS 55th International Symposium & Exhibition | |
| Applied Surface Science | Tuesday Sessions |
| Session AS-TuP |
| Session: | Aspects of Surface Analysis Poster Session |
| Presenter: | Y. Sakai, University of Yamanashi, Japan |
| Authors: | Y. Sakai, University of Yamanashi, Japan Y. Iijima, JEOL Ltd. R. Takaishi, University of Yamanashi, Japan D. Asakawa, University of Yamanashi, Japan K. Hiraoka, University of Yamanashi, Japan |
| Correspondent: | Click to Email |
A giant cluster ion impact method, electrospray droplet impact (EDI) ionization, has been developed for matrix-free secondary ion mass spectrometry.1 EDI utilizes the electrospray charged water droplet as the extremely high-momentum projectiles. The charged water droplets formed by electrospraying 1M acetic acid aqueous solution at atmospheric pressure are passed through an orifice into the vacuum chamber, transported into a quadrupole ion guide, accelerated by 10kV after exiting the ion guide and impact on a target. Roughly, the charged water droplets may be represented as [(H2O)90000+100H]100+ with mass of~1.6x106 u. The kinetic energy of impacting projectile is ~106 eV.2 The polymer samples (PET, PMMA, PS) etched by EDI were evaluated by X-Ray Photoelectron Spectrometer (XPS: JEOL JPS-9200). A comparative study for PET, PMMA and PS etched by Ar+ ion and EDI was made. For the surfaces of PET, PMMA and PS etched by Ar+ ion, the deoxygenation and graphitization were found. The degradations of the polymers by the ion sputtering are slightly suppressed by using the low energy ion or the cluster ion. But, the effect of suppressing degradations was depended on the polymers. On the other hand, the deoxygenation, and graphitization were not observed on the surfaces of PET, PMMA and PS etched by EDI. It supposed that the kinetic energy of impinging water droplet at the moment of impact on the target by EDI is efficiently converted to the internal energies of water molecules in the selvedge of the colliding interface. The rest is dissipated as shock waves propagating through the target and the water droplet. This verifies that EDI is capable of no degradations of the polymer surface etching. The other experimental results of EDI applied to metals, semiconductors will be given. Acknowledgement: This work was supported by the Japan Science and Technology Agency.
1K.Hiraoka, D.Asakawa, S.Fujimaki, A.Takamizawa, K.Mori, Eur.Phys. J. D 38 (2006) 225
2K.Hiraoka, K.Mori, D.Asakawa, J.Mass Spectrom., 41 (2006) 894.