Dresden 2003 – wissenschaftliches Programm
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DS: Dünne Schichten
DS 19: Ionenstrahlverfahren II – Oberfl
ächenmodifizierung
DS 19.1: Vortrag
Donnerstag, 27. März 2003, 17:00–17:15, GER/37
Time and azimuth dependent evolution of Ar+ ion bombardment induced nanogrooves on Cu(001) — •Herbert Wormeester, Mikhail Ovsyanko, Georgiana Stoian und Bene Poelsema — MESA+ Research Institute, University of Twente, Enschede, NL
With HR-LEED we found that the distance between the nanogrooves[1], L, initially depends on the sputter time in a diffusion like behaviour: L2=L02+St. The initial average distance L0 and the slope S both depend on temperature and ion flux. For sputtering along [110] and [100] we find the same L0, while S is higher along [100]. The value of L0 implies the following creation scenario: The vacancies nucleate first into small islands, with a distance governed by diffusion and the vacancy creation rate. Tthe islands get elongated along the plane of incidence. They preferentially coalesce along this direction to form nanogrooves. The temporal behavior of the distance L differs: Along [100], L finally saturates at values depending on substrate temperature and slightly on ion flux. Along [110] no saturation is observed. The self-anneal behavior of the nanogrooves has been studied too. [1] S. van Dijken, D. de Bruin and B. Poelsema, Phys. Rev. Lett. 86, 4608 (2001).