J. Phys. Colloques
Volume 50, Number C8, Novembre 198936th International Field Emission Symposium
|Page(s)||C8-459 - C8-464|
J. Phys. Colloques 50 (1989) C8-459-C8-464
PULSED LASER ATOM PROBE CHARACTERIZATION OF SILICON CARBIDEM.K. MILLER1, P. ANGELINI1, A. CEREZO2 et K.L. MORE1
1 Metals and Ceramics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, U.S.A.
2 Department of Metallurgy and Science of Materials, University of Oxford, GB-Oxford 0X1 3PH, Great-Britain
Field-ion microscopy and field evaporation of α-SiC and β-SiC materials have been successfully demonstrated. Since field-ion micrographs could be taken immediately after pulsed field evaporation, the effects of preferential field evaporation of silicon that occurred under ramped field evaporation were eliminated. However, due to the high electrical resistivity of silicon carbide, conventional voltage pulsed field evaporation was not practical and pulsed laser field evaporation was required. No significant variations in performance were found as a function of laser wavelength but the full-width-at-half maximum mass resolution of 0.4 amu was inferior to voltage pulsed field evaporation of metals. In addition, the background noise level was considerably higher. Within the statistical accuracy of the analyses, the compositions were found to be slightly deficient in silicon. These experiments also revealed that the laser power required to field evaporate SiC was greater than for other semiconducting materials.