Plasma-Enhanced ALD of TiO 2 using a Novel Cyclopentadienyl Alkylamido Precursor [Ti(Cp Me )(NMe 2 ) 3 ] and O 2 plasma A. Sarkar, 1 S. E. Potts, 1 S. A. Rushworth, 2 F. Roozeboom, 1 M. C. M. van de Sanden, 1 W. M. M. Kessels 1 1 Dept. of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands 2 SAFC Hitech Ltd., Power Road, Bromborough, Wirral CH62 3QF, UK Titanium oxide thin films of both amorphous and anatase morphologies have been deposited using remote plasma ALD over a wide temperature range (100-350 °C), using a novel heteroleptic alkylamido precursor Ti(Cp Me )(NMe 2 ) 3 . A high growth per cycle (GPC) of 0.07-0.08 nm (which is about 50 % higher than the GPC obtained with most other organometallic precursors) without any nucleation delay was observed. Rutherford backscattering (RBS) and X-ray photoelectron spectroscopy (XPS) studies on the deposited films revealed their stoichiometry and compositional purity: samples deposited at 100-350 °C had [O]/[Ti] ratios of ~2.0 ± 0.1. Samples deposited at 200 °C and above had C, H and N concentrations of less than 0.6, 2 and 2.3 at.%, respectively. Atomic force microscopy (AFM) and X-ray diffraction (XRD) studies revealed that films deposited at 300 °C and above had a significant crystalline (anatase) component, while films deposited at 100 and 200 °C were amorphous. Introduction Titanium oxide is a well-established, commercial material with wide-spread fields of application, owing mainly to its non-toxicity, abundance and high refractive index. Emerging applications include dye-sensitized solar cells (1,2), photocatalysis (3,4), while its high dielectric constant makes it an interesting material in the semiconductor industry (5). Furthermore, due to the recent emergence of ternary and mixed oxides like strontium titanate (SrTiO 3 ) (6), bismuth titanate (BTO) (7) and barium strontium titanate [(Ba,Sr)TiO 3 ] (8) as promising ultrahigh-k dielectrics, there is a renewed interest in developing vapor phase-based TiO 2 deposition processes, which ensure chemical and process compatibility with Sr-containing and other organometallic precursors. Additionally, for deposition of TiO 2 , accurate control over the film stoichiometry, compositional purity and nanostructure (amorphous, anatase or rutile crystalline phases) is desired for applications such as dynamic random access memory (DRAM) capacitors (5,9), and electrochemical sensors (10,11). This not only requires precursors with high reactivity, volatility and good thermal stability over a wide temperature range, but also appropriate deposition techniques and processes to meet these stringent processing requirements (12). ECS Transactions, 33 (2) 385-393 (2010) 10.1149/1.3485274 ©The Electrochemical Society 385 Downloaded 04 Nov 2010 to 131.155.113.36. Redistribution subject to ECS license or copyright; see http://www.ecsdl.org/terms_use.jsp