FAST-ELECTRON BEAM LITHOGRAPHY SYSTEM WITH 1024 BEAMS INDIVIDUALLY CONTROLLED BY BLANKING APERTURE ARRAY

A new electron beam lithography system with a two-dimensional blanking aperture array (BAA) is proposed. The BAA produces 1024 individually controlled beams. The demagnification ratio of BAA on the wafer is 0.3 %. An actual BAA device was fabricated and a preliminary experiment wa s carried out with a block exposure system and Si stencil mask. Very h igh resolution of 0.08 mum holes was confirmed. The system parameters are designed by setting the system throughput at more than twenty 8-in ch wafers per hour. Below a 0.2 mum minimum feature size, BAA exposure is suitable for random patterning of wiring layers in dynamic random access memories (DRAMs), application specified integrated circuit (ASI Cs) and microcode processing units (MPUs), and will be a useful lithog raphic tool.