TANDEM OPTICAL SCANNER/STEPPER AND PHOTOEMISSION CONVERTER FOR ELECTRON BEAM LITHOGRAPHY

摘要

A combined photo and electron beam lithography tool takes advantage of the high throughput of optical lithography and the high spatial resolution of electron lithography. The tool includes two subsystems, the first of which is a conventional photolithography tool, for instance a stepper or scanner, and the second of which is a demagnifying electron beam column. These two subsystems are coupled by a photoemission cathode. This allows device fabrication entailing pattern delineation of minimum feature size significantly smaller than 0.5 νm. The total demagnification of this system is achieved in two steps where first a photo image of a mask is generated by the conventional photolithography tool, with unity magnification or demagnification, and the photon image is converted into an electron beam image by the photoemission cathode, and subsequently this image is demagnified by an electron beam column.