ELECTRON-BEAM CELL-PROJECTION LITHOGRAPHY SYSTEM

An electron-beam exposure system HL-800D has been developed for the mass production of both quarter micron large-scale integrated memories and application specific integrated circuits (ASICs). To achieve a productive level of throughput, the system utilizes a cell-projection method combined with variable shaped method and a continuously moving stage at variable speed depending on the pattern density. The system is operated at a 50 kV acceleration voltage and a 1 muC/cm2 dosage. Three stage deflectors have been developed to assure high-speed deflection and highly accurate positioning. A fast pattern controller generates patern data at 200 ns shot-cycle-time with the positioning error correction and proximity effect correction. A high-speed ceramic XY stage and an automatic wafer loder have been developed. The system is operated by a workstation which also provides data conversion. The estimated throughput of the system is 11 wafers/h for 0.3 mum ASICs and 20 wafers/h for quarter micron memories.