3646
J. Phys. Chem. 1996, 100, 3646-3651
Spark-Gap Atomic Emission Microscopy P. G. Van Patten, J. D. Noll, and M. L. Myrick* Department of Chemistry and Biochemistry, UniVersity of South Carolina, Columbia, South Carolina 29208
C. R. Li and T. S. Sudarshan Department of Electrical Engineering, UniVersity of South Carolina, Columbia, South Carolina 29208 ReceiVed: June 6, 1995; In Final Form: NoVember 15, 1995X
A new technique allowing elemental analysis of small regions of scanning tunneling microscopy (STM) substrates without loss of tip-surface registry has been developed. The technique is based on spark atomic emission spectroscopy and provides information normally unavailable from the STM. In this technique, a voltage excursion (>100 V) is used to excite the sample and cause emission. Spectra from a polished copper electrode surface are presented and discussed. Important parameters and present limitations are also discussed along with future directions for the improvement and long-term use of the technique.
Introduction Scanning probe microscopy (SPM) has in recent years revolutionized surface science by allowing enormous advances in surface imaging technology. Scanning tunneling microscopy1 (STM) is the most commonly used type of SPM used for the imaging of metals and semiconductors. Though state-of-theart instruments allow imaging of surface features with extremely high resolution (
