摘要:
An electron beam column comprises a thermal field emission electron source to generate an electron beam, an electron beam blanker, a beam shaping module, and electron beam optics comprising a plurality of electron beam lenses. In one version, the optical parameters of the electron beam blanker, beam shaping module, and electron beam optics are set to achieve an acceptance semi-angle β of from about ¼ to about 3 mrads, where the acceptance semi-angle β is the half the angle subtended by the electron beam at the writing plane. The beam-shaping module can also operate as a single lens using upper and lower projection lenses. A multifunction module for an electron beam column is also described.
摘要:
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.
摘要:
Fabrication of 0.25 gm design rule or smaller devices on chips, that may attain levels of 256 megabit or higher depends upon lithographic patterning by use of accelerated charged particle beams. Fabrication is expedited by acceleration values resulting in deBroglie wavelengths at least in order of magnitude smaller than such design rule to permit cost saving both in fabricating apparatus and resulting devices. Most importantly, such wavelength values permit significant variation in spatial angle of incidence of beam to wafer to permit both large instantaneous exposure areas and in temporal angle of incidence to expedite beam scanning as emitted from a fixed particle source.