The relationship between electron and ion induced secondary electron imaging: A review with new experimental observations

The phenomenalogical and theoretical aspects of secondary electron emission due to ion bombardment in the keV energy range has been reviewed and a comparision of this process with secondary electron emission due to electron bombardment has been made. The similarities and differences between the contrasts in the secondary electron images of test specimens studied with both scanning microfocused Ga + beams and electron beams have been explained by the mechanisms of the secondary electron emission processes. From ion induced secondary electron images information on the topography, material and crystallographic nature of specimens can be obtained with high surface sensitivity. Differences in surface potential on different areas of a specimen has also been shown to result in voltage contrast effects.