Patent Number: 
Section: claims

1. A writing apparatus comprising:a deflection position calculation unit configured to calculate a deflection position for a first pattern by using a design position for the first pattern, and to calculate a deflection position for a second pattern by using a design position for the second pattern, the second pattern being complementary to the first pattern;a storage device configured to store a correction map;a correction unit configured to read the correction map from the storage device, and to correct the deflection position for the first pattern based on the correction map, and to correct the deflection position for the second pattern based on the correction map;a writing unit configured to write a first pattern at the deflection position for the first pattern, which has already been corrected and a plurality of measurement patterns for measurement onto a first mask substrate using a charged particle beam; andan addition unit configured to add a positional deviation amount of the first pattern having been written on the first mask substrate to the deflection position for the second pattern, which has already been corrected,wherein positional deviation amounts of the plurality of measurement patterns, the first pattern and the plurality of measurement patterns having been written onto the first mask substrate, are measured, the positional deviation amount of the first pattern is obtained by using the positional deviation amounts of the plurality of measurement patterns measured, and the writing unit writes the second pattern being complementary to the first pattern at the deflection position of the second pattern, to which the positional deviation amount of the first pattern has already been added, onto a second mask substrate using a charged particle beam. 2. The apparatus according to claim 1, wherein positional deviation amounts of the first pattern are measured at a plurality of positions on a surface of the first mask substrate, and the addition unit adds a value at a position of the first pattern calculated from an approximate equation acquired from positional deviation amounts of the first pattern, measured at the plurality of positions, as the positional deviation amount at the position of the first pattern, to the writing position of the second pattern corresponding to the position of the first pattern. 3. The apparatus according to claim 1 further comprising a storage unit configured to store a map showing a positional deviation amount at any position of the first pattern,wherein the addition unit reads the map from the storage unit and acquires a positional deviation amount of the first pattern to be added to a position of the second pattern, from the read map. 4. The apparatus according to claim 3, wherein an approximated value at each coordinate of the map is calculated using an approximate equation acquired from positional deviation amounts of the plurality of patterns for measurement. 5. The apparatus according to claim 4 wherein the approximated value at a coordinate of the map is used as the positional deviation amount of the first pattern to be added to a position of the second pattern corresponding to the coordinate. 6. A writing method comprising:calculating a deflection position for a first pattern by using a design position for the first pattern;reading a correction map from a storage device, and correcting the deflection position for the first pattern based on the correction map;writing a first pattern at the deflection position for the first pattern, which has already been corrected and a plurality of measurement patterns for measurement onto a first mask substrate using a charged particle beam;measuring positional deviation amounts of the plurality of measurement patterns, the first pattern and a plurality of measurement patterns having been written on the first mask substrate;obtaining a positional deviation amount of the first pattern by using the positional deviation amounts of the plurality of measurement patterns;calculating a deflection position for a second pattern by using a design position for the second pattern;reading the correction map from the storage device, and correcting the deflection position for the second pattern based on the correction map;adding the positional deviation amount of the first pattern to the deflection position for the second pattern, which has already been corrected, the second pattern being complementary to the first pattern; andwriting the second pattern being complementary to the first pattern at a deflection position of the second pattern, to which the positional deviation amount of the first pattern has already been added, onto a second mask substrate using a charged particle beam onto a second mask substrate.