Scanning electron microscope with eddy-current compensation
Compensated magnetic deflection coil for electron beam lithography system
Electron beam exposure system and an apparatus for carrying out the same
Automatic focus and deflection correction in E-beam system using optical target height measurements
Variable axis immersion lens electron beam projection system
Charged particle beam apparatus Patent #: 4701623
ApplicationNo. 243274 filed on 09/12/1988
US Classes:250/398, With target means250/396MLMagnetic lens
ExaminersPrimary: Anderson, Bruce C.
Attorney, Agent or Firm
Foreign Patent References
International ClassH01J 037/04
Foreign Application Priority Data1987-09-16 JP
AbstractA method for compensating for an eddy current effect due to leakage flux of a magnetic lens in a charged particle beam exposure system, and a system for exposing the beam on a substrate while a stage carrying the substrate is moving. By employing this method and system, a step and repeat system can be operated while the stage is moving, while improving the throughput of the system. A deviation in the path of the charged particle beam caused by the eddy current is proportional to the velocity of the stage. To compensate for this, a proportional constant relating the deviation to the velocity of the stage is measured in advance, and a correction term which is a product of the speed of the stage and the proportional constant, is fed back to a deflector of the charged particle beam. The proportional constant is obtained from a shift of an image of a test pattern viewed on a CRT in a SEM mode, from a first position at which the stage is stationary to a second position while the stage is moving at a constant speed.