| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide OHI rails including pairs of parallel conductors that are fed by alternating current (AC) signals which generate magnetic fields that introduce errors in electron beam systems, in which AC power supply systems also generate magnetic fields that introduce particle beam location errors. <P>SOLUTION: The system includes one or more sensors that are placed distantly from each other for sensing magnetic noises within at least one predefined frequency band thereby to provide magnetic noise measurements with synchronous detection of the location of a charged particle beam. Based on the magnetic noise measurements and on relationships between values of the magnetic noises and particle beam location errors, magnetic noise compensation signals are generated. An object is then scanned by a particle beam in response to a desired particle beam scan pattern and the magnetic noise compensation signals. <P>COPYRIGHT: (C)2013,JPO&INPIT |
