AVS 49th International Symposium
    Thin Films Monday Sessions
       Session TF-MoA

Paper TF-MoA6
Plasma Chemistry Aspects versus Material Properties Related to Textured Zinc Oxide Deposition and Etching using an Expanding Thermal Plasma

Monday, November 4, 2002, 3:40 pm, Room C-101

Session: Transparent Conductive Coatings
Presenter: R. Groenen, Eindhoven University of Technology, The Netherlands
Authors: R. Groenen, Eindhoven University of Technology, The Netherlands
E.R. Kieft, Eindhoven University of Technology, The Netherlands
M. Creatore, Eindhoven University of Technology, The Netherlands
J.L. Linden, TNO, The Netherlands
M.C.M. Van de Sanden, Eindhoven University of Technology, The Netherlands
Correspondent: Click to Email
Zinc oxide (ZnO) is a transparent conducting oxide (TCO) of considerable technological interest. As recently shown, a new approach for low temperature ZnO deposition is developed, using an expanding thermal argon plasma created with a cascaded arc.@footnote 1@ (Co)precursors are oxygen and diethylzinc. Films are deposited on glass substrates at a temperature from 300 down to 150°C at a rate up to 1 nm/s. A rough surface texture, which is essential for application as front electrode in thin film solar cells, is obtained during deposition. Quadrupole mass spectrometry is used to correlate film properties and gas phase composition. Gas specific calibrations have been performed to make quantitative measurements of the stable reaction product concentrations. First insights into the chemical processes taking place in the plasma have been obtained. There appears to be a close relation between detected species and the observed texture development, which allows for further improvement of the material light trapping properties. Especially the role of hydrogen is under investigation. In this respect, a new method for dry ZnO etching using an expanding thermal argon - hydrogen plasma created with a cascaded arc has been demonstrated, obtaining etch rates up to over 10 nm/s. In-situ ellipsometry, as well as ex-situ FTIR, AFM, SEM, and Hall measurements have been applied to characterize the effect of etching on film properties. @FootnoteText@@footnote 1@R. Groenen, et al., Appl. Surf. Sci. 173 (2001) 40.