RASTER SHAPED BEAM, ELECTRON BEAM EXPOSURE STRATEGY USING A TWO DIMENSIONAL MULTIPLEXEL FLASH FIELD

摘要

An apparatus includes: a rasterizer which rasterizes a surface of the substrate into pixels and outputs gray levels values, where the gray level values specify a proportion of a pixel that overlaps with the pattern; a buffer coupled to receive and store the gray level values from the rasterizer; a flash converter coupled to receive the gray level values from the buffer, where the flash converter outputs shape data that define a flash field; a dose value circuitry coupled to the rasterizer, where the dose value circuitry computes dose values associated with the shape data; a converter coupled to receive the shape data from the flash converter and associated dose values from the dose value circuitry, where the converter outputs signals that specify a shape of the flash field, duration of the flash field, and a position of the flash field on the substrate; and a charged particle beam column coupled to receive the signals from the converter, and which generates the flash field as specified by the signals from the converter.