The contrast mechanism in low voltage scanning electron microscopy of single-walled carbon nanotubes

The contrast mechanism for scanning electron microscopy images of single-walled carbon nanotubes (SWNTs) is studied for samples on various substrates using low voltage scanning electron microscopy (LVSEM). We show that the contrast of SWNT images is greatly affected by a charging effect, where the brightness strongly depends on the supply of charges available to the SWNTs and the charging characteristics of the substrate. We demonstrate that the charging effect in LVSEM can be utilized to obtain images of various SWNT device structures to provide rapid feedback for the device fabrication process.