Dresden 2009 – wissenschaftliches Programm
O 19.3: Vortrag
Dienstag, 24. März 2009, 11:00–11:15, SCH A215
Ion beam pattern formation on Si(001) with and without codeposition — •Sven Macko and Thomas Michely — II. Physikalisches Institut, Universität zu Köln, Germany
Si(001) is sputtered with ion fluences > 1022 ions/m2 and at angles ϑ = 0∘−83∘ with respect to the surface normal. Sputtering was performed under UHV conditions with a differentially pumped and scanning fine focus ion source. The chamber pressure rose to ≈ 9 × 10−8 mbar during erosion and great care was exercised to sputter the Si sample only. At room temperature for ϑ = 0∘−45∘ no pattern formation was observed. To the contrary, rough starting surfaces smoothened. For flat starting surfaces the roughness remained below 3 Å. The observed absence of roughness partly agrees and partly disagrees with observations in the literature. We tested the effect of codeposition, either through physical vapor phase depsoition or sputter deposition. At room temperature, with ion fluences > 5 × 1021 ions/m2, Mo sputter codeposition leads to regular, concentration dependend patterns of dots and ripples. At elevated temperatures also other codeposited materials give rise to large surface roughness.