A method of tip-sample distance control based on electrostatic force in maskless microplasma scanning etching

In cantilever-based microplasma etching system proposed by our group, the controlling of tip-sample distance is important for maskless canning etching. This paper presents a tip-sample controlling method based on electrostatic force. Theoretical model to calculate the electrostatic force between the conductive probe and the sample is established. The relationship of the electrostatic force and the tip-sample distance under different bias voltages is investigated by experiments based on AFM. Both the theory and experiments prove that this electrostatic force is feasible for maskless scanning plasma etching with the etching distance of 1-2μm.