Proximity correction using computer aided proximity correction (CAPROX): Evaluation and application

Abstract

Direct write electron beam lithography requires proximity effect correction to achieve high fidelity. CAPROX (computer aided proximity correction) serves this purpose. It preserves hierarchy as far as possible, thus reducing memory and CPU time. The program guides the evaluation of the correction parameters. The need for and the result of correction is judged evaluating exposures written at a reduced dose in optical white light interference contrast microscopy. If the color observed in large and small structures is equal, no poximity effect correction is necessary. We applied CAPROX to correct structures written in positive and negative resists using the Philips EBPG-4 and the JEOL JBX-5D11 beam writer. The proximity effect correction is indispensable for the fabrication of an ACMOS-ASIC with 1 μm minimum features written in 1.8 μm thick negative resist.