Patent ID: 8519364

Claim:
A positioning system for a precise stage comprising: a designed pattern, placed on a moving stage, comprising a plurality of gradually wider marks arranged radially with a space therebetween; an electron beam column, for generating a focused electron beam; a scanning unit connected to the electron beam column, for adjusting the focused electron beam to perform two-dimensional pattern scanning over the designed pattern so as to generate a reflected electron signal; an electron detection unit, for detecting the reflected electron signal; and a control unit connected to the moving stage, the electron beam column, the scanning unit and the electron detection unit, wherein the reflected electron signal is generated from the two-dimensional pattern scanning of the focused electron beam over the gradually wider marks and the space therebetween; the reflected electron signal is converted by the control unit to generate a clock signal and the control unit adjusts the movement of the moving stage according to pulse width of the plurality of clock signals.