| 摘要 |
An electron-beam array lithography (EBAL) system and method of operation which employs an electron beam column of the array optics type having an array lens assembly, an array fine deflector assembly and a coarse deflector assembly, is described. The method and system derives fiducial marking signals from a lenslet stitching grid of fiducial elements, formed on a standard stitching target, for calibrating the boundaries of the fields of view of the respective elements of the array of lenslets. The fiducial marking signals are used to stitch together the individual fields of view of the elements in the array of lenslets. The same stitching calibration target, a precise copy, or similar precisely mapped target is used to calibrate all of the exposure stations of a multi-station EBAL system with the result that any level of multi-level registered patterns can be exposed in any of the so calibrated EBAL exposure stations. In the event of flawed lenslets in the array lens, the locations of those parts of the exposed area which were subject to the fields of view of flawed lenslets in the array lens assembly are mapped in a computer memory and this information is used to blank the electron beam during any period that the coarse deflector might be directing the beam to a flawed lenslet. The system and method physically permutes the position of target area to a new physical position subject to the field of view of a different working lenslet. Appropriate coarse and fine deflection signals are obtained, and the electron beam then is caused to retrace over the areas previously subject to the field of view of flawed lenslets in accordance with the master pattern specifications whereby increased yield from the EBAL system is obtained.
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