SUDRAUD PIERRE,CORBIN ANTOINE,SAILER RAINER,BATE DAVID JOHN
申请号：
US19990308372
公开号：
US6365898(B1)
申请日:
1999.09.13
申请国别(地区):
美国
年份:
2002
代理人:
摘要：
A scanning electron microscope has means for generating a beam of electrons which is scanned over a specimen held within a holder in a chamber which contains a gaseous medium. A negative potential is applied to the holder so as to generate an electric field which accelerates secondary electrons, formed by the interaction or the primary beam with the specimen, in a direction away from the specimen surface and into a collision zone in the chamber. In that zone, the accelerated secondary electrons collide with gas molecules of the gaseous medium, thereby initiating a cascade of collisions which, in effect, amplifies the secondary electron signal. That signal (which may take the form of photons generated as a result of the collisions) is detected by detecting means, such as a photo-multiplier.
