Patent ID: 6037589
Filing Date: 2000-03-14
Classification: H01J

Abstract:
In an electron beam observation instrument, a compound magnetic and electrostatic objective lens comprising: a single pole magnetic lens having a top face with a single magnetic pole disposed between an electron beam source and a sample; and an electrostatic immersion lens comprising an upper electrode and a lower electrode, a substantial portion of the upper electrode of the electrostatic immersion lens is disposed inside a yoke forming the top face of the single pole magnetic lens, one end of the upper electrode is disposed between the top face of the single pole portion of the magnetic lens and the sample and a lower electrode of the electrostatic immersion lens is disposed between the upper electrode and the sample; wherein a deceleration electric field is generated between the upper electrode and the lower electrode, generation of an asymmetrical electric field is prevented and high resolution observation of the sample is allowed.