AVS 60th International Symposium and Exhibition
    Applied Surface Science Wednesday Sessions
       Session AS-WeA

Paper AS-WeA12
Interface Analysis of ALD Grown Oxides using Tunable HAXPES

Wednesday, October 30, 2013, 5:40 pm, Room 204

Session: Developments in Electron Spectroscopies for Non-Ideal Samples 2
Presenter: J. Church, University of Delaware
Authors: J. Church, University of Delaware
J. Krajewski, University of Delaware
R. Opila, University of Delaware
C. Weiland, National Institute of Standards and Technology (NIST)
Correspondent: Click to Email
The roadmap for the development electronic device world follows Moore’s law. New challenges appear at with each node. Presently there is a need to find effective ways to characterize a few monolayers of material. In this study, Atomic Layer Deposition (ALD) thin films of ZrO2 and Nb2O5 films have been studied using high-energy synchrotron-based x-ray photoemission spectroscopy, performed at the NIST beamline at the National Synchrotron Light Source. ALD permits precise control of oxide composition, thickness, and coverage. As a result, thin high dielectric constant materials, which are routinely deposited by ALD, are seeing more applications. Given the unique beam energy tuning ability of synchrotron based sources the x-rays are able to effectively probe the interface of ZrO2 and Nb2O5 layers with their respective substrates. Binding energy shifts associated with the chemical environment at the interface of up to 1.4 eV and 1.1 eV for the ZrO2 and Nb2O5films respectively have been found. These energy shifts suggest significant charge transfer at the interface between the high-k oxide and the Si. In addition, the composition and chemistry of the films as a function of thickness has been determined non-destructively by converting a series of spectra taken with different incident x-ray energies (and simultaneously, different photoelectron sample depths) to depth profiles using Bayesian analyses.