SurfaceScience21 – wissenschaftliches Programm
O 74.8: Poster
Mittwoch, 3. März 2021, 13:30–15:30, P
Low-temperature atomic layer deposition of indium oxide thin films using trimethylindium and oxygen plasma — •Ali Mahmoodinezhad1, Carlos Morales1, Franziska Naumann2, Paul Plate2, Robert Meyer2, Christoph Janowitz1, Karsten Henkel1, Małgorzata Kot1, and Jan Ingo Flege1 — 1Brandenburg University of Technology Cottbus-Senftenberg, K.-Zuse-Str. 1, 03046 Cottbus, Germany — 2SENTECH Instruments GmbH, Schwarzschildstraße 2, 12489 Berlin, Germany
Indium oxide thin films were deposited on Si (100) by plasma-enhanced atomic layer deposition (PEALD) using trimethylindium (TMIn) and oxygen plasma (O2) in a low-temperature range of 80 to 200 ∘C. The In2O3 layers were characterized by in-situ spectroscopic ellipsometry (SE), ex-situ X-ray photoelectron spectroscopy (XPS) and electrical measurements. The SE data show a growth rate of 0.56 Å/cycle within the ALD window (100 to 150 ∘C) with a thickness inhomogeneity of ≤1.2%. In addition, the highest refractive index is 2.07 (at 632.8 nm) for the layer grown at 150 ∘C, and the films exhibit indirect and direct band gaps of 2.8±0.1 eV and 3.3±0.2 eV, respectively. XPS characterization indicates no carbon incorporation and a temperature-dependent off-stoichiometry of the layers. The chemical analysis of the In 3d and O 1s core levels confirms the formation of In-O bonds and suggests the additional presence of hydroxyl groups and defects. With increasing temperature, the contribution of OH groups and defects decreases whereas that of In-O bonds increases. Notably, higher growth temperatures result in an indium rich phase within the layers.