New neutralization method for measuring the secondary electron yield of insulative material

Purpose The limitation of the traditional bias neutralization method is proved, and a new neutralization method is proposed to measure the secondary electron yield of insulating materials.
Method While measuring the secondary electron yield of an insulating sample using the bias neutralization method, the region of an insulating sample irradiated by an electron beam may not be neutralized, because electrons enforced by the bias are not returned to the proper location. The above-mentioned phenomenon is verified by a simulation. To achieve proper neutralization, we propose a method of moving the electron beam to irradiate the metal sample stage without applying a bias voltage, which generates many low-energy electrons around the insulating sample. Those electrons are automatically attracted to the positively charged region of the insulating sample surface and rejected if enough electrons accumulated on the surface.
Result and conclusion The limitation of neutralization of bias voltage was verified by simulation, and the new neutralization method was proved to be effective through experiments.