Method for maskless lithography

Claim 1

A method for maskless projection lithography, the method comprising the steps of: a) providing a two-dimensional array of individually addressable micromirrors, each micromirror comprising a plurality of moveable substrates having a reflecting surface, said reflecting surface for reflecting light from a light source into an imaging means entrance pupil, said reflecting surfaces modified by coating said surfaces with a non-reflecting coating and etching away only a portion of said non-reflective coating, thereby providing said reflecting surfaces with features for minimizing coherence and diffraction effects in said reflected light, said features comprising: i) a reflecting surface having a shape consisting essentially of an octagon having regular trapezoidal projections laying at every other side of said octagon and wherein the wider base of each of said trapezoidal projections is contiguous with said octagon, ii) a reflecting surface having a dimension measured in a scan direction which is at least one-half of a center-to-center distance between adjacent micromirrors; and iii) a reflecting surface have an edge which includes a plurality of phase reversed features and small light attenuating features along said edge; b) illuminating said array with said source of light, said light reflected by each of said micromirrors comprising a pixel having a light distribution profile, said reflected light imaged by said imaging means in a distant focal plane, said imaged light comprising rows or columns of pixels arranged so that adjacent pixels adds constructively to provide smooth and continuous straight regions of light and dark lines, said lines having a minimum width comprising a single row or a single column of said pixels; c) controllably moving said micromirrors so as to orient each such that said light reflected by said reflecting surfaces is directed either into or away from said imaging means entrance pupil; and d) sequencing the movement of said micromirrors so as to cause each of said micromirrors to move in proper sequence so as to scan a predetermined coordinate pattern across said array of micromirrors, in said scan direction, thereby causing an image of said pattern to be reproduced in said focal plane, said sequencing means including temporally interleaving rows of said micromirrors where said rows are parallel to said scan direction.

Claim 2

A method for maskless projection lithography, the method comprising the steps of: a) providing a two-dimensional array of individually addressable micromirrors, each micromirror comprising a plurality of moveable substrates having a reflecting surface, said reflecting surface for reflecting light from a light source into an imaging means entrance pupil, said reflecting surfaces modified by coating said surfaces with a non-reflecting coating and etching away only a portion of said non-reflective coating, thereby providing said reflecting surfaces with features for minimizing coherence and diffraction effects in said reflected light, said features comprising: i) a reflecting surface having a shape consisting essentially of an octagon having regular trapezoidal projections laying at every other side of said octagon and wherein the wider base of each of said trapezoidal projections is contiguous with said octagon, ii) a reflecting surface having a dimension measured in a scan direction which is at least one-half of a center-to-center distance between adjacent micromirrors; and iii) a reflecting surface have an edge which includes a plurality of phase reversed features and small light attenuating features along said edge; b) illuminating said array with said source of light, said light reflected by each of said micromirrors comprising a pixel having a light distribution profile, said reflected light imaged by said imaging means in a distant focal plane, said imaged light comprising rows or columns of pixels arranged so that adjacent pixels adds constructively to provide smooth and continuous straight regions of light and dark lines, said lines having a minimum width comprising a single row or a single column of said pixels; c) controllably moving said micromirrors so as to orient each such that said light reflected by said reflecting surfaces is directed either into or away from said imaging means entrance pupil; and d) sequencing the movement of said micromirrors so as to cause each of said micromirrors to move in proper sequence so as to scan a predetermined coordinate pattern across said array of micromirrors, in said scan direction, thereby causing an image of said pattern to be reproduced in said focal plane, said sequencing means including temporally interleaving rows of said micromirrors where said rows are parallel to said scan direction.