Multi-level resolution lithography

A method for lithographic rastering of an image, defined by an array of pixels, onto an image-accepting substrate, the method comprising the steps of:

• decomposing an image, defined by an array of image pixels that are spaced apart from each other, into a collection of one or more isolated pixel arrays that together form the image, where an array has a nearest neighbor pixel-to-pixel distance d.sub.nn ;
• decomposing each isolated pixel array into a first pixel assembly, a second pixel assembly and a third pixel assembly, where the first pixel assembly contains only image pixels that are within a distance of P.d.sub.nn from a boundary of the isolated pixel array and that have a pixel width of at least P1 pixels, where P and P1 are selected positive integers with 2.ltoreq.P1.ltoreq.P, where the second pixel assembly contains only image pixels that are within a distance P.d.sub.nn from a boundary of the isolated pixel array and that have a pixel width of not more than P1-1 pixels, and the third pixel assembly contains all image pixels not in the first pixel assembly and not in the second pixel assembly;
• irradiating the pixels contained in the first pixel assembly with a first irradiation beam that has a selected beam width of at least P1 pixels;
• irradiating the pixels contained in the second pixel assembly with a second irradiation beam that has a selected beam width of no more than P1-1 pixels;
• and
• irradiating the pixels contained in the third pixel assembly with a third irradiation beam that irradiates at least N3 contiguous pixels, where N3 is a selected integer .gtoreq.2.

Apparatus for lithographic rastering of an image, defined by an array of pixels, onto an image-accepting substrate, the apparatus comprising:

• a source of an electrically charged particle beam;
• and
• a computer that is connected to and controls the charged particle beam source, where the computer is programmed to:
• decompose an image, defined by an array of image pixels that are spaced apart from each other, into a collection of one or more isolated arrays of pixels that together form the image, where an array has a nearest neighbor pixel-to-pixel distance d.sub.nn ;
• decompose each isolated pixel array into a first pixel assembly and a second pixel assembly, where the first pixel assembly contains only image pixels that are within a distance P.d.sub.nn of a boundary of the isolated pixel array, where P is a selected positive integer, and the second pixel assembly contains all image pixels not in the first pixel assembly;
• cause the charged particle beam source to irradiate the pixels contained in the first pixel assembly with a first irradiation beam that has a selected beam width of N1.d.sub.nn, where N1 is a selected integer satisfying 1.ltoreq.N1.ltoreq.P;
• and
• cause the charged particle beam source to irradiate the pixels contained in the second pixel assembly with a second irradiation beam that irradiates at least N2 contiguous pixels, where N2 is a selected integer .gtoreq.2.

Apparatus for lithographic rastering of an image, defined by an array of pixels, onto an image-accepting substrate, the apparatus comprising:

• a source of an electrically charged particle beam;
• and
• a computer that is connected to and controls the charged particle beam source, where the computer is programmed to:
• decompose an image, defined by an array of image pixels that are spaced apart from each other, into a collection of one or more isolated pixel arrays that together form the image, where an array has a nearest neighbor pixel-to-pixel distance d.sub.nn ;
• decompose each isolated pixel array into a first pixel assembly, a second pixel assembly and a third pixel assembly, where the first pixel assembly contains only image pixels that are within a distance of P.d.sub.nn from a boundary of the isolated pixel array and that have a pixel width of at least P1 pixels, where P and P1 are selected positive integers with 2.ltoreq.P1.ltoreq.P, where the second pixel assembly contains only image pixels that are within a distance P.d.sub.nn from a boundary of the isolated pixel array and that have a pixel width of not more than P1-1 pixels, and the third pixel assembly contains all image pixels not in the first pixel assembly and not in the second pixel assembly;
• cause the charged particle beam source to irradiate the pixels contained in the first pixel assembly with a first irradiation beam that has a selected beam width of at least P1 pixels;
• cause the charged particle beam source to irradiate the pixels contained in the second pixel assembly with a second irradiation beam that has a selected beam width of no more than P1-1 pixels;
• and
• cause the charged particle beams source to irradiate the pixels contained in the third pixel assembly with a third irradiation beam that irradiates at least N3 contiguous pixels, where N3 is a selected integer .gtoreq.2.