Münster 1999 – wissenschaftliches Programm
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DS: Dünne Schichten
DS 3: Ionenimplantation III
DS 3.3: Fachvortrag
Montag, 22. März 1999, 14:30–14:45, PC 7
Dynamic annealing of ion-beam induced damage in α-Quartz — •S. Dhar1, W. Bolse2, and K.P. Lieb1 — 1II. Physikalisches Institut and SFB 345, Universit"at G"ottingen, 37073 Göttingen — 2Institut für Strahlenphysik, Universität Stuttgart, 70569 Stuttgart
SiO2, apart from its conventional use in Si devices, is one of the key materials for photo-electronic applications such as optical storage and broadband communication. Ion implantation is used in various device processing steps and induces damage whose stability is crucial in many applications. In many other cases, on the other hand, damage recovery is essential. This contribution addresses the understanding of accumulation of ion-beam induced damage and its dynamic annealing in (0001) α-quartz at elevated temperatures. The samples were irradiated with 50 keV 20Ne+ ions at temperatures between 80 and 975 K and fluences from 1× 1013 to 4 × 1015 ions/cm2. RBS channeling results show that amorphization occurs via random nucleation and growth of the disordered phase and can be inhibited above a critical temperature Tc ∼ 940 K. The critical fluence φc for amorphization is independent of temperature up to 550 K and then increases rapidly at higher temperatures. The activation energies both for dynamic defect recovery within the collision cascade and for regrowth at the amorphous/crystalline interface were found to be 0.28±0.02 eV. The results will be discussed in the light of the vacancy out-diffusion model of Morehead and Crowder [1].
[1] F. F. Morehead and B. L. Crowder, Radiat. Eff. 6, 27 (1970).