A research on the surface charge with different coating tip by Electrostatic Force Microscope

Electrostatic Force Microscope (EFM) is applied to study of the properties of surface charge of polyimide films in micro-nanometer scale. The charge was injected by different kind of coating tips to the surface of polyimide films. After that the surface charge was characterized by EFM, the result indicated that it was difficult to inject charge with Pt/Ir coating tip for larger work function than Co/Cr coating. The mechanism of electron emission electrode in the experiment is mainly hot electron emission, but also accompanied by field emission. So the barrier height between metal and dielectric had massive influence on the process of Charge injection. This research provides a new method for study on the rule and mechanism of surface charge on the insulated films.