AVS 58th Annual International Symposium and Exhibition
    Thin Film Division Tuesday Sessions
       Session TF-TuA

Invited Paper TF-TuA10
In Situ Studies of Oxide ALD for Crystalline Oxide Growth on Silicon

Tuesday, November 1, 2011, 5:00 pm, Room 107

Session: ALD: Fundamental Reactions and Film Properties
Presenter: Brian Willis, University of Connecticut
Authors: B.G. Willis, University of Connecticut
H. Wang, University of Connecticut
C. Zhang, Chinese Academy of Sciences, China
X. Jiang, University of Connecticut
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Thin films of crystalline oxides integrated with silicon are of interest for novel electronic devices that utilize a rich variety of functional properties of oxide materials. These useful properties include piezoelectricity and ferroelectricity among others. Growth of crystalline oxides on silicon requires careful control of a nanometer thin transition region between the film and substrate to avoid deleterious side reactions such as oxidation of the substrate. Submonolayer surface reconstructions of alkaline earth metals such as Sr are critical for controlling the interface for successful growth. In this paper, we show how atomic layer deposition (ALD) can be used to precisely control the interface reactions for epitaxial growth. X-ray photoelectron spectroscopy and in-situ spectroscopic ellipsometry are used to monitor the growth and interface evolution of oxides deposited by ALD. Ellipsometry provides real time feedback on sequential adsorption cycles including precursor adsorption and oxidation. X-ray photoelectron spectroscopy provides detailed insight into the evolution of the interface structure during annealing and oxide desorption. Using this high degree of control enables the successful deposition of critical Sr/Si reconstructions for heteroepitaxy. The results show that ALD crystalline oxide heteroepitaxy is promising.