Scanning type electron microscope

Abstract

Abstract PURPOSE: To obtain the whole number of the variation ratio when operating distance is varied in inserting an amplifier or attenuator having a gain which equals to the product of operating distance ratio and a reciprocal number of a whole number close to the ratio into an electron beam deflecting power source. CONSTITUTION: When operating distance is changed from l 2 Wl 1 while keeping the amplification factor of the amplifier/attenuator 8 at 1, the multiplying ratio at both positions becomes RM=M 1 /M 2 =l 2 /l 1 . When l 2 /l 1 is not whole number , the multiplying ratio RM is not whole number naturally. Thus, the amplification factor of the amplifier/attenuator 8 is switched by the operating distance switch 9 so that it becmoes 1 when the operating distance is l 2 and becomes CM=l 2 /l 1 when the operating distance is l 1 N and N becomes a whole number close to l 2 /l 1 . With such a system, low multiplying ratio can be easily obtained by longer operating distances and also correction for displaying value ot the multiplying ratio displayer can be simplified. In addition, clear multiplying ratio values can be obtained consistently without the multiplying ratio being varied continuously. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Osamu Yamada

Bibliographic Details