| AVS 61st International Symposium & Exhibition | |
| Plasma Science and Technology | Wednesday Sessions |
| Session PS-WeA |
| Session: | Plasma Diagnostics, Sensors, and Control |
| Presenter: | Jerome Dubois, LTM - CEA/LETI, France |
| Authors: | J. Dubois, LTM - CEA/LETI, France G. Cunge, LTM - CEA/LETI, France N. Posseme, CEA-LETI, France M. Darnon, LTM - CEA/LETI, France L. Vallier, CNRS-LTM, France O. Joubert, LTM - CEA/LETI, France |
| Correspondent: | Click to Email |
Hydrogen plasmas have been used for decades in the microelectronic industry with applications in the fields of deposition (PECVD, Plasma Enhanced Chemical Vapor Deposition) [1], etching [2] and surface treatment (reduction of the photoresist roughness in the lithography step [3]). However hydrogen is a very peculiar element due to his low mass and his electronegative character, and the mechanisms at stake in low pressure hydrogen plasma aren’t well understood yet. A complete fundamental study with reliable diagnostics would be highly valuable for many applications [4]. Moreover, hydrogen plasmas present a great potential interest for the treatment of new materials such as graphene [5] or carbon nanotubes [6]. To modify the surface of such ultrathin layers without damaging the material, very low ion energy bombardment is required (conditions such as those obtained in pulsed ICP reactor [7]). By contrast, for other applications such as etching of several nanometer thick layers, the ion energy must be very high to get a significant etch rate. To assist the development of innovative processes in H2 plasmas, we have thus analyzed systematically CW and pulsed H2 plasmas both with and without RF bias power. In particular, we carry out time-resolved ion flux, and time-averaged ion energy measurements in different pulsing configurations. A large variety of ion energies and shapes of IVDF are reported depending on pulsing parameters. The IVDF are typically very broad (due to the low ion transit time of low mass ion through the sheath) and either bi or tri-modal (H+, H2+ and H3+ contributions). The time variations of the ion flux in pulsed plasmas also presents peculiar features that will be discussed.
References
1. W. A. Lanford, and M. J. Rand, Journal of Applied Physics, 49, 2473-2477 (1978)
2. A. Efremov, N. K. Min, J. Jeong, Y. Kim, and K. H. Kwon, Plasma Sources Science and Technology, 19 (2010)
3. E. Pargon, L. Azarnouche, M. Fouchier, K. Menguelti, R. Tiron, C. Sourd, and O. Joubert, Plasma Processes and Polymers, 8, 1184-1195 (2011)
4. M. Sode, T. Schwarz-Selinger, and W. Jacob, Journal of Applied Physics, 113 (2013)
5. E. Despiau-Pujo, A. Davydova, G. Cunge, L. Delfour, L. Magaud, and D. B. Graves, Journal of Applied Physics, 113 (2013)
6. A. Hassanien, M. Tokumoto, P. Umek, D. Vrbanic, M. Mozetic, D. Mihailovic, P. Venturini, and S. Pejovnik, Nanotechnology, 16, 278 (2005)
7. C. Petit-Etienne, M. Darnon, P. Bodart, M. Fouchier, G. Cunge, E. Pargon, L. Vallier, O. Joubert, and S. Banna, Journal of Vacuum Science & Technology B, 31 (2013)