Target locking system for electron beam lithography

摘要: An e-beam lithographic system capable of in situ registration. The has an optics section such as a VAIL lens. A controllable stage moves substrate with respect to the beam axis place writing fields beneath beam. field locking target between and aperture sized permit write on substrate. includes alignment or registration marks around aperture. differential interferometric measures relative positions controls position. patterns by basis. As is moving into position for each field, swept until it hits marks, thereby checking alignment. control data, i.e., coil currents necessary hit are stored, drift correction values calculated from data. Meanwhile, pattern compensated values.