Patent Number: 
Section: claims

1. A method for forming a desired pattern on a surface with an electron beam, the method comprising the steps of: projecting an electron beam through a first mask boundary area and onto a surface where a part of the desired pattern is to be formed, the first mask boundary area including a first mask portion of the desired pattern and a first accuracy evaluation element;  projecting an electron beam through a second mask boundary area and onto the surface so that a projection of the electron beam through the second mask boundary area on the surface overlaps a projection of the electron beam through the first mask boundary area on the surface, the second mask boundary area having a second mask portion of the desired pattern and a second accuracy evaluation element,  the overlapping projections of the electron beams through the first and second accuracy evaluation elements merging to form a complete accuracy evaluation pattern on the surface,  the overlapping projections of the electron beams through the first and second mask portions of the desired pattern merging to form the part of the desired pattern on the surface when the first and second mask boundary areas are aligned; and  measuring an alignment of the first and second mask boundary areas by measuring an alignment of the complete accuracy evaluation pattern on the surface. 2. The method of  claim 1 , wherein the first accuracy evaluation element is an annular border and the second accuracy evaluation element is a corresponding shape that fits entirely within the annular border when the first and second mask boundary areas are aligned. claim 1 3. The method of  claim 1 , wherein the first accuracy evaluation element is a first slide caliper and the second accuracy evaluation element is a corresponding second slide caliper that abuts the first slide caliper when the first and second mask boundary areas are aligned. claim 1 4. The method of  claim 1 , further comprising the step of realigning the first and second boundary areas based on the measured alignment of the complete accuracy evaluation pattern on the surface. claim 1 5. The method of  claim 1 , wherein the first mask boundary area and the second mask boundary area are on opposite edges of one mask. claim 1 6. The method of  claim 1 , wherein the first mask boundary area and the second mask boundary area are on edges of separate masks. claim 1 7. The method of  claim 2 , wherein the annular border is a first square and the corresponding shape is a second square that is smaller than the first square. claim 2 8. A device for forming a desired pattern on a surface with an electron beam, the device comprising: a projector that projects an electron beam through a first mask boundary area and onto a surface where a part of the desired pattern is to be formed, where said first mask boundary area includes a first mask portion of the desired pattern and a first accuracy evaluation element;  said projector also projecting an electron beam through a second mask boundary area and onto said surface so that a projection of the electron beam through said second mask boundary area on said surface overlaps a projection of the electron beam through said first mask boundary area on said surface, where said second mask boundary area includes a second mask portion of the desired pattern and a second accuracy evaluation element,  the overlapping projections of the electron beams through said first and second accuracy evaluation elements merging to form a complete accuracy evaluation pattern on said surface,  the overlapping projections of the electron beams through said first and second mask portions of the desired pattern merging on said surface to form the part of the desired pattern on said surface when said first and second mask boundary areas are aligned; and  a measurement device that measures an alignment of said first and second mask boundary areas by measuring an alignment of said complete accuracy evaluation pattern on said surface. 9. The device of  claim 8 , wherein said first accuracy evaluation element is an annular border and said second accuracy evaluation element is a corresponding shape that fits entirely within said annular border when said first and second mask boundary areas are aligned. claim 8 10. The device of  claim 8 , wherein said first accuracy evaluation element is a first slide caliper and said second accuracy evaluation element is a corresponding second slide caliper that abuts said first slide caliper when said first and second mask boundary areas are aligned. claim 8 11. The device of  claim 8 , further comprising means for realigning said first and second boundary areas based on the measured alignment of said complete accuracy evaluation pattern on said surface. claim 8 12. The device of  claim 8 , wherein said first mask boundary area and said second mask boundary area are on opposite edges of one mask. claim 8 13. The device of  claim 8 , wherein said first mask boundary area and said second mask boundary area are on edges of separate masks. claim 8 14. The device of  claim 9 , wherein said annular border is a first square and said corresponding shape is a second square that is smaller than said first square. claim 9