ECS J. Solid State Sci. Technol.-2012-Xu-N107-14.pdf (2.26 MB)

Atomic Layer Deposition and Characterization of Amorphous ErxTi1-xOy Dielectric Ultra-Thin Films

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journal contribution
posted on 02.01.2014 by Runshen Xu, Christos G. Takoudis
Er1-xTixOy dielectric thin films were deposited on Si(100) substrates by atomic layer deposition (ALD) using tris(methylcyclopentadienyl) erbium [(CpMe)(3)Er] and tetrakis(diethylamino) titanium [TDEAT] as metal precursors, and O-3 as oxidant. The deposition temperature dependence of both Er2O3 and TiO2 film growths showed the overlapping ALD window of 175-250 degrees C. Compositional tunability of Er1-xTixOy films was obtained through deposition process control. Carbon and nitrogen impurities in as-deposited films were found to be below X-ray photoelectron spectroscopy detection level. Glancing incidence X-ray diffraction and phase-shifting interferometry results showed that ErxTi1-xOy films with ALD cycle ratios (Er2O3/TiO2) of 1: 8 or higher have a good thermal stability and remain amorphous with unchanged surface roughness after post-deposition rapid thermal processing (RTP) at 700 degrees C in O-2. Electrical measurements showed that optimized amorphous Er1-xTixOy films after RTP exhibited a dielectric constant of similar to 36, a hysteresis voltage of less than 10 mV, and a leakage current density of 10(-8) A/cm(2) at - 1 MV/cm; such properties compare favorably with the properties of other reported amorphous titanium-based ternary dielectrics on Si. The sizable reduction of leakage current density of Er1-xTixOy found in our study suggests that amorphous Er1-xTixOy thin films are promising future dielectrics in Si integrated circuit technology.




This project was supported by the National Science Foundation (GOALI 0329195, EEC 1062943 and CBET 1067424).


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© The Electrochemical Society, Inc. 2012. All rights reserved. Except as provided under U.S. copyright law, this work may not be reproduced, resold, distributed, or modified without the express permission of The Electrochemical Society (ECS). The archival version of this work was published in ECS Journal of Solid State Science and Technology.


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