Regensburg 2004 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 12: Poster I

HL 12.83: Poster

Montag, 8. März 2004, 16:30–19:00, Poster A

Real-time spectroscopic ellipsometry monitoring of a ZnO thin film pulsed laser deposition growth — •N. Ashkenov¹, M. Schubert¹, H. Hochmuth¹, M. Lorenz¹, M. Grundmann¹, and B. Johs² — ¹Fakultät für Physik und Geowissenschaften, Institut für Experimentelle Physik II, Universität Leipzig, Linnéstraße 5, 04103 Leipzig — ²J. A. Woollam Co., 650 ’J’ Street, Suite 39,Lincoln, NE 68508 USA

Real-time in-situ optical monitoring and control of thin-film growth processes provides depth-resolved optical properties of heteroepitaxial layer structures. Semiconductor device structures based on ZnO and its isolectronically mixed (Mg,Cd)_xZn_1−xO compounds are promising candidates for next-generation UV optoelectronics, which can be grown by pulsed laser deposition (PLD). Substrate temperature, growth rate, layer thickness and composition can be accessed by in-situ spectroscopic ellipsometry. A two-step PLD growth mode of a (0001) ZnO thin film on (0001) Al₂O₃ substrate at 1053 K was monitored in-situ in the photon energy range from 1.25 eV to 3.335 eV. Changes in the growth rate and in the optical properties of the ZnO film throughout the deposition process are determined utilizing the generalized virtual interface approach. Detailed knowledge about the unintentional variations in the deposition conditions can be used for feed-back control in order to optimize the PLD growth process. A simple ZnO dielectric function model approach is developed, which can be used to control the ZnO film growth in real time.