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DS: Fachverband Dünne Schichten
DS 42: Poster I: Progress in Micro- and Nanopatterning: Techniques and Applications (jointly with O); Spins in Organic Materials; Ion Interactions with Nano Scale Materials; Organic Electronics and Photovoltaics; Plasmonics and Nanophotonics (jointly with HL and O); High-k and Low-k Dielectrics (jointly with DF); Organic Thin Films; Nanoengineered Thin Films; Layer Deposition Processes; Layer Properties: Electrical, Optical, and Mechanical Properties; Thin Film Characterisation: Structure Analysis and Composition; Application of Thin Films
DS 42.3: Poster
Mittwoch, 16. März 2011, 15:00–17:30, P1
Surfactant assisted ion beam erosion of GaN and AlN surfaces — •Kun Zhang1, Ulrich Vetter1, Nils Borth1, Hans-Gregor Gehrke1, Ramasamy Jayavel2, and Hans Hofsäss1 — 1II. Physikalisches Institut, Universität Göttingen, 37077 Göttingen, Germany — 2Centre for Nanoscience and Technology, Anna University Chennai, 600025 India
We investigate the evolution of the surface morphology of AlN and GaN surfaces during ion beam erosion. AlN and GaN films grown on sapphire substrates were irradiated at room temperature with few keV Xe ions at normal ion incidence with ion fluences up to 4*1017 cm−2. The surface morphology was analyzed using atomic force microscopy and scanning electron microscopy. For GaN selective sputtering causes segregation of Ga on the surface, resulting in a dense coverage with small spherical Ga droplets. With increasing ion fluence the droplet size increases. The Ga coverage was quantitatively analyzed with SEM and Rutherford backscattering. For AlN, the rms roughness of the surface decreases with increasing ion fluence from initially 8 nm to about 3 nm at 4*x1017 cm−2. No ripple or dot patterns were observed. Sputtering of AlN with simultaneous co-deposition of Ga, results in the formation of randomly distributed small Ga droplets and Al0.8Ga0.2 islands of few nm in size on the AlN surface. The rms roughness of such a surface is only about 1.3 nm. The density of droplets and islands decreases with increasing ion fluence. In the intermediate regions the AlN surface appears rather flat with rms roughness well below 1 nm.