Patent ID: 7482277
Filing Date: 2009-01-27
Classification: H01L

Abstract:
1. A method of multilevel microfabrication processing for a plurality of lithographic layers comprising: providing a planar substrate that comprises one or more material layers; adding a first patterned hardmask layer placed on top of the substrate and patterned into the lithographic pattern desired for the top lithographic layer; adding subsequent patterned hardmask layers until the number of hardmask layers equals the number of lithographic layers desired; the second-from-the-bottom hardmask layer being patterned into the lithographic pattern desired in the second-from-the-top lithographic layer; if the number of lithographic layers desired is at least three, the third-from-the-bottom hardmask layer being patterned into the pattern desired in the third-from-the-top lithographic layer; if the number of lithographic layers desired is at least four, the fourth-from-the-bottom hardmask layer being patterned into the pattern desired in the fourth-from-the-top lithographic layer; for any number of lithographic layers, this correspondence is continued until the pattern of the top hardmask layer corresponds to the pattern desired in the bottom lithographic layer; etching into the substrate followed by completely removing the top hardmask layer once all desired hardmask layers are added; and alternating etching into the substrate and completely removing a hardmask layer until the bottom hardmask layer is removed.