AVS 49th International Symposium
    Nanometer Structures Wednesday Sessions
       Session NS-WeP

Paper NS-WeP1
Electrostatic Force Spectroscopy of Pure InP and Self-assembled InAs/InP Quantum Dots Studied by Non-contact Atomic Force Microscopy

Wednesday, November 6, 2002, 11:00 am, Room Exhibit Hall B2

Session: Nanometer Structures B
Presenter: R.-P. Stomp, McGill University, Canada
Authors: R.-P. Stomp, McGill University, Canada
S. Studenikin, National Research Council, Canada
P. Poole, National Research Council, Canada
A. Sachrajda, National Research Council, Canada
P. Grutter, McGill University, Canada
Correspondent: Click to Email
The purpose of this work is to develop a low-temperature, non-contact Electric Force Microscope (EFM) technique to image semiconductor dots embedded in a dielectric matrix. Non-contact Atomic Force Microscope (nc-AFM) is a very versatile tool to study conductive as well as non-conductive surfaces without damaging them. Our microscope operates at 4.5K with a built-in heater and the possibility of applying a magnetic field up to 8T.@footnote 1@ In this study we use samples of self-assembled InAs quantum dots embedded in InP grown by chemical beam epitaxy.@footnote 2@ In the present study, we are investigating the change in resonance frequency of the AFM tip as function of tip-sample bias voltage, or electrostatic force spectroscopy, of bare InP and InAs/InP quantum dot. In case of bare InP an asymmetric frequency-voltage dependence was observed that enabled us to determine the charge sign of the carrier and to deduce the work function potential of the material. This is an on going work, and results on the quantum dot samples will be presented and discussed. It has been previously demonstrated that quantum dot spectra can be measured by EFM, where we can observe the filling of energy levels at low temperature.@footnote 3@ @FootnoteText@ @footnote 1@ M. Roseman., P.Gruetter, Rev. Sci. Instr. 71, 3782 (2000)@footnote 2@ J. Lefebvre, P.J. Poole et al., J. Cryst. Growth, 234, 391 (2002)@footnote 3@ D. Aykutlu, Y. Yamamoto, cond-mat/0103125 (2001) .