Raster shaped beam writing strategy system and method for pattern

Abstract

A hybrid exposure strategy for pattern generation uses wide field raster scan deflection and a uniformly moving stage to expose long stripes. Periodic analog wide field magnetic scan is augmented by a high speed electrostatic retrograde scan to keep the beam stationary during exposure of rectangular flash fields. The system's data path utilizes a pattern represented in a rasterized format. Intermediate vector data bases are created using fracture rules that limit feature and hierarchical cell size of to be smaller than overlapping fringes of stripe data fields. Rectangular flash fields are employed with each field being a 1 by n array of writing pixels. The length, origin position and dose of line shaped beam flashes can be varied to allow patterns to be exposed on a design grid much smaller than a writing pixel. The length, origin position and dose data for each flash is derived from a rasterized data format using a decoder device. In this manner multiple writing pixels are exposed simultaneously without compromising resolution or diagonal line edge roughness, thus enhancing exposure rate. A high flash rate is assured by including astigmatic illumination to maximize beam current, and leveraged co-planar blanking and shaping deflection to minimize drive voltages.