AVS 59th Annual International Symposium and Exhibition
    Applied Surface Science Thursday Sessions
       Session AS-ThA

Invited Paper AS-ThA8
Hard X-ray Photoelectron Spectroscopy (HAXPES) Investigations of Electronic Materials and Interfaces

Thursday, November 1, 2012, 4:20 pm, Room 20

Session: Applications of Large Cluster Ion Beams - Part 2 (2:00-3:20 pm)/ Surface Analysis using Synchrotron Techniques (3:40-5:40 pm)
Presenter: J.C. Woicik, National Institute of Standards and Technology
Correspondent: Click to Email
Photoelectron spectroscopy can uniquely measure the chemical and electronic structure of solids and films; however, owing to the generally limiting electron inelastic mean-free path of lab based instruments, the technique is extremely surface sensitive, probing only the first several atomic layers of a given structure. For this reason, synchrotron based hard x-ray photoelectron spectroscopy (HAXPES) in which the photon energy can be varied between 2.1 and 6 keV has emerged as a technique that is ideally suited for studying the electronic and chemical structures of advanced materials systems. In this talk, we will discuss developments of the HAXPES technique at the NIST beamline X24A at the National Synchrotron Light Source for the study of electronic materials. Examples will include nitrogen treatment of HfO2 gate stacks on Si, depth profiling of the HfO2/SiO2 interface, Ga and As “out-diffusion” at semiconductor/oxide interfaces, band offsets and Schottky barrier heights at semiconductor/oxide and diamond/metal interfaces, and oxygen vacancies in N doped TiO2 and solid-oxide fuel cells. In all cases, the increased probing depth of HAXPES over traditional lab based XPS is crucial to study the electronic structure of entire overlayers and/or buried interfaces with thicknesses of industrial significance.