A novel method for the discharge of electrostatic mirror formations in the scanning electron microscope

Abstract

A method for the removal of electrostatic mirror formations in the scanning electron microscope (SEM) was conceptualised and implemented. This method utilises the controlled rampdown of the primary beam voltage to achieve mirror discharge. It is found that the new technique is effective in enabling imaging from high-beam voltages (20 kV) down to low voltage (1 kV) without the loss of imaging capability due to electrostatic mirrors. The entire discharge cycle could be performed in ≤ 4 min depending on sample and operating conditions. Hence, this technique compares favourably with the time needed to air the specimen chamber for mirror removal, but without the disadvantage of disrupting SEM operation. This method holds great promise in applications where the imaging of insulating samples at both high and low kV ranges are required.