Patent Number: 
Section: claims

1. A method for fabricating an x-ray mask tool, comprising the steps of: providing a silicon substrate;  forming a first photoresist layer onto a top surface of said substrate;  aligning an image patterning mask onto said photoresist layer, wherein said mask has portions that block light and portions which transmit light;  exposing said photoresist layer to a source of broadband light;  removing said mask;  developing said first photoresist layer and removing a portion of said photoresist thereby exposing areas of said silicon substrate;  anisotropically etching said exposed areas to a depth of at least about 10 microns providing thereby a plurality of etched structures having etched walls and bases;  removing the remaining photoresist;  depositing a thin first layer comprising a metal or metals onto said silicon top surface and onto said etched walls and bases;  depositing a thicker second metal layer over said first layer such that said etched structures are completely filled;  planarizing said substrate top surface to remove said metal layers from said top surface; and  thinning said substrate from a substrate bottom surface in order to achieve a substrate thickness of less than about 100 microns in a region beneath said etched structures. 2. The method of  claim 1 , wherein the step of providing a silicon substrate comprises providing a silicon substrate that is a standard industry silicon wafer. claim 1 3. The method of  claim 1 , wherein the steps of depositing first and second metal layer includes depositing a metal selected from the group consisting of the Transition series of metal listed in New IUPAC Group Numbers 4-12 of the Period Table of elements, aluminum, tin, and alloys thereof. claim 1 4. The method of  claim 1 , wherein the first step of depositing comprises depositing a metal layer by particle or thermed vapor deposition. claim 1 5. The method of  claim 4 , wherein said first step of depositing includes depositing a layer of chromium followed by depositing a layer of gold. claim 4 6. The method of  claim 1 , wherein the second step of depositing comprises depositing a metal layer by electroplating. claim 1 7. The method of  claim 1 , wherein said second step of depositing includes electroplating a layer of gold. claim 1 8. The method of  claim 1 , wherein the step of forming a first photoresist layer onto said substrate comprises spin-coating a Novolak photoresist layer on said substrate. claim 1 9. The method of  claim 1 , wherein the step of aligning an image patterning mask comprises aligning a positive trace image patterning mask. claim 1 10. The method of  claim 1 , wherein the step of aligning an image patterning mask comprises aligning a negative trace image patterning mask. claim 1 11. A method for fabricating an x-ray mask tool, comprising the steps of: providing a doped silicon substrate, said dopant rendering said substrate electrically conductive;  forming a first photoresist layer onto a top surface of said substrate;  aligning an image patterning mask onto said photoresist layer, wherein said mask has portions that block light and portions which transmit light;  exposing said photoresist layer to a source of broadband light;  removing said mask;  developing said first photoresist layer and removing a portion of said photoresist thereby exposing areas of said silicon substrate; anisotropically etching said exposed areas to a depth of at least about 10 microns providing thereby a plurality of etched structures having etched walls and bases;  removing the remaining photoresist;  depositing a thick first layer comprising a metal of metals onto said silicon top surface and onto said etched walls and bases such that said etched structure are completely filled;  planarizing said substrate top surface to remove said metal layers from said top surface; and  thinning said substrate from a substrate bottom surface in order to achieve a substrate thickness of less than about 100 microns in a region beneath said etched structures.