Accession Number : ADP007935

Title :   Formation of Submicrometer Carbonaceous Islands during SEM Examination of Thin GaAs Layers on Si Substrates,

Corporate Author : MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB

Personal Author(s) : Turner, G. W. ; Nitishin, P. M.

Report Date : 22 MAY 1992

Pagination or Media Count : 8

Abstract : In the course of investigating the initial stages of GaAs growth on Si substrates by molecular beam epitaxy (MBE), we have discovered an electron-beam-induced growth process that can occur during scanning electron microscope (SEM) examination of samples with a sufficiently thin deposit of GaAs. When such a sample is transferred from the MBE system to the SEM with only a brief exposure to air, a circular island forms at any location on the surface where the SEM electron beam is allowed to dwell. The diameter of such islands increases from about 500 to 2500 A as the dwell time is increased from about 1 min to over 10 min. Carbon was the only element detected when the islands were analyzed by an Auger microprobe after surface contamination was removed by sputtering.

Descriptors :   *CARBON, *MICROPROBES, *EPITAXIAL GROWTH, *DEPOSITION, AIR, CIRCULAR, CONTAMINATION, DEPOSITS, DIAMETERS, DWELL TIME, ELECTRON BEAMS, ELECTRONS, MICROSCOPES, MOLECULAR BEAMS, SCANNING ELECTRON MICROSCOPES, SPUTTERING, SUBSTRATES, SURFACES, GALLIUM ARSENIDES, SILICON, AUGER ELECTRON SPECTROSCOPY.

Subject Categories : Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE