Electron beam array lithography system employing multiple parallel array optics channels and method of operation

摘要

A multi-channel EBAL apparatus and method of operation employing a plurality of parallel operated electron beam channels with each electron beam channel being of the fly's eye array optics type having an electron gun for producing an electron beam, an array lenslet assembly and an associated fine deflector assembly together with a coarse deflector for selectively directing the electron beam to a desired array lenslet within the array lenslet assembly. The associated fine deflector element thereafter directs the electron beam to a desired point on a target surface such as a target semiconductor wafer being processed by electron beam lithography. A common movable stage is provided for supporting the target wafer surfaces below the plurality of parallel operated electron beam channels and for moving the target surfaces in common relative to the array optics axes of all of the electron beam channels. Common movement of all of the target surfaces is achieved automatically in preprogrammed manner preferably along either axis of an x-y translation mechanism. All of the electron beam channels are supported within a common housing which is evacuated along with the movable target platform which serves to move the target surfaces in common. The apparatus can be employed in conjunction with a pattern registration grid mapped with the aid of a lenslet stitching calibration grid and which provides fiducial marking signals for identifying the boundaries of the field of view of the respective lenslets in each electron beam channel as well as the field of view of all of the electron beam channels and for stitching together the required number of the fields of view to thereby cover a desired area of a target surface. Provision is made for accommodating the occurance of any flawed lenslet assemblies by permuting the target surface so as to place any portion of a target surface that had been subject to a flawed lenslet under the view of an unflawed lenslet for subsequent electron beam treatment. Increased production capacity can be obtained by connecting a plurality of such EBAL apparatuses in parallel and controlling them in common by an overall system executive computer.