Patent Number: 051503921
Section: claims

1. A structure for providing precise alignment in the x,y dimensions and precise gap control in the z dimension between a mask and a wafer in a lithography system comprising: a wafer to be lithographically exposed to radiation having a raised alignment mark on the upper surface thereof,  a mask disposed over said wafer, said mask having radiation transparent areas for permitting radiation to strike said wafer in predetermined patterns,  said mask having at least one physical opening therein including a cantilever member portion of said mask material projecting from an edge of said mask opening into said opening, said cantilever member being constrained only at one end at said edge of said opening and being free to move in the Z dimension at the end opposite said edge of said opening,  a tip affixed to the said opposite end of said projecting cantilever position of said mask material,  gap control means, including a tip, disposed vertically in the Z dimension over said opposite end of said projecting cantilever, said gap control means further including means for moving said tip into contact with said projecting cantilever for bending said cantilever down toward said wafer in Z dimension to a predetermined gap spacing distance,  means for raising said wafer upward in the Z dimension until substantially proximate said tip on said projecting cantilever,  and means for translating said wafer in the X and Y dimensions until said sharp tip on said projecting cantilever is in contact with said alignment mark. 2. A structure according to claim 1 wherein said cantilever member is composed of said mask material and is contiguous with said mask at said constrained end. 3. A structure according to claim 2 wherein said radiation transparent areas are thin membrane areas of said mask having thicknesses significantly less than the thickness of said mask such that radiation passes through said membrane areas and is blocked by said thicker mask. 4. A structure according to claim 2 wherein said radiation is a beam of X-rays. 5. A structure according to claim 2 wherein said gap control means includes a piezoelectric transducer.