| AVS 59th Annual International Symposium and Exhibition | |
| Plasma Science and Technology | Wednesday Sessions |
| Session PS2-WeA |
| Session: | Plasma Surface Interactions during PECVD and Plasma Surface Modification |
| Presenter: | G. De Temmerman, FOM Institute DIFFER, Netherlands |
| Authors: | G. De Temmerman, FOM Institute DIFFER, Netherlands K. Bystrov, FOM Institute DIFFER, Netherlands M.J. Baldwin, University of California San Diego R.P. Doerner, University of California San Diego L. Marot, University of Basel, Switzerland H.Y. Xu, Tsinghua University, China M.C.M. van de Sanden, FOM Institute DIFFER, Netherlands |
| Correspondent: | Click to Email |
The interaction of energetic particles with solid surfaces is at the core of numerous applications such as thin film deposition or materials processing. Ion-beam processing, for example, allows nanostructure formation on metal and semiconductor surfaces, while reactive ions can be used to chemically modify surfaces during nitriding for example. Those processes usually involve ions with energies above 100eV where ion-induced damage creation and physical sputtering are expected, and are relatively well documented. In a fusion reactor, at locations where the plasma intersects with the solid surfaces, plasma-facing surfaces are bombarded by extreme particle fluxes (up to 1024m-2s-1 or 1.6x105A.m-2), albeit with energies below 50eV. While the ion energy is below the damage threshold for the incoming ions, the particle flux is high enough to cause a local supersaturation of mobile gas particles within the implantation zone and strong surface morphology changes as a result of cluster/bubble growth.
Combining a high efficiency plasma source and a strong magnetic field, linear plasma devices (LPD) can generate such high ion fluxes and allow fundamental studies of plasma-induced surface modifications under high heat and particle fluxes. The effect of high fluxes of hydrogen, helium and neon ions on metal surfaces, such as tungsten, has been investigated over a wide range of surface temperatures (300-2000C) and ion energies (10-50eV). In all cases, the surface modifications depend strongly on these two parameters, which control the near-surface particle trapping and material properties (mechanical properties, self-diffusion).
Nanostructuring of the surface through formations of ripples or nanoscopic voids is observed for hydrogen irradiation. In the case of helium, a fibreform nanostructure is formed with a typical size in the range 20-1000nm depending on the surface temperature. For neon ions, both a fine-scale ripple structure and large blisters are observed on the surface.
An overview of these results will be given with an emphasis on the surface properties and the application of low-energy ion fluxes as a surface processing technique.