Patent Number: 
Section: claims

1. A pattern drawing method for drawing a desired pattern on a base material by irradiating an electronic beam onto the base material, said method comprising:scanning a first region of the base material with the electronic beam in a first dose amount;scanning a boundary region continuous with the first region with the electronic beam alternately in the first dose amount and in a second dose amount; andscanning a second region continuous with the boundary region with the electronic beam in the second dose amount. 2. The pattern drawing method of claim 1, wherein at least one surface of the base material comprises a curved surface having groove sections formed thereon with a predetermined pitch;wherein each groove section includes a side wall and an inclined section extending from a top of the side wall to a bottom of a side wall of an adjacent groove section; andwherein the inclined section comprises at least one of each of the first region, the boundary region and the second region. 3. The pattern drawing method of claim 1, wherein a difference between the fist dose amount and the second dose amount is a minimum adjustable dose amount based on a minimum clock of a D/A converter for driving an electronic beam gun for irradiating the electronic beam. 4. The pattern drawing method of claim 1, wherein in the boundary region, areas scanned with the electronic beam in the first dose amount are alternated in a sub scanning direction with areas scanned with the electronic beam in the second dose amount. 5. The pattern drawing method of claim 1, wherein in the boundary region, each of a number of areas scanned with the electronic beam in the first dose amount and a number of areas scanned with the electronic beam in the second dose amount is adjusted in accordance with a desired inclination angle. 6. The pattern drawing method of claim 1, wherein in the boundary region, a duty ratio of a first area scanned with the electronic beam in the first dose amount and a second area scanned with the electronic beam in the second dose amount within one pitch of the first area is adjusted in accordance with a desired inclination angle. 7. The pattern drawing method of claim 1, wherein in the boundary region, both (i) each of a number of first areas scanned with the electronic beam in the first dose amount and a number of second areas scanned with the electronic beam in the second dose amount, and (ii) a duty ratio of a first area scanned with the electronic beam in the first dose amount and a second area scanned with the electronic beam in the second dose amount within one pitch of the first area, are adjusted in accordance with a desired inclination angle. 8. The pattern drawing method of claim 1, wherein in the boundary region, areas scanned with the electronic beam in the first dose amount are alternated in a main scanning direction with areas scanned with the electronic bean in the second dose amount. 9. The pattern drawing method of claim 8, wherein in the boundary region, positions of the areas scanned with the electronic beam in the second dose amount in the main scanning line are staggered with respect to positions of areas scanned with the electronic beam In the second dose amount in adjacent main scanning lines. 10. The pattern drawing method of claim 8, wherein in the boundary region, the areas scanned with the electronic beam in the first dose amount are alternated on a main scanning line with the areas scanned with the electronic beam in the second dose amount. 11. The pattern drawing method of claim 10, wherein in the boundary region, positions of the areas scanned with the electronic beam in the second dose amount in the main scanning line almost align with positions of areas scanned with the electronic beam in the second dose amount in adjacent main scanning lines. 12. The pattern drawing method of claim 10, wherein in the boundary region, positions of the areas scanned with the electronic beam in the second dose amount in the main scanning line are different from positions of areas scanned with the electronic beam in the second dose amount in adjacent main scanning lines. 13. The pattern drawing method of claim 1, wherein in the boundary region, widths of areas scanned with the electronic beam in the first dose amount and widths of areas scanned with the electronic beam in the second dose amount are smaller than a diameter of the electronic beam. 14. A pattern drawing apparatus, comprising:a drawing section to draw a desired pattern on a base material by irradiating an electronic beam to the base material;a storing section to store dose amount information including a first dose amount and a second dose amount;a control section to control the drawing section based on the dose amount distribution information to scan a first region of the base material with the electronic beam in the first dose amount, to scan a boundary region continuous with the first region with the electronic beam alternately in the first dose amount and the second dose amount, and to scan a second region continuous with the boundary region with the electronic beam in the second dose amount. 15. The pattern drawing apparatus of claim 14, wherein the storing section stores information corresponding to a shape of the base material; andwherein the pattern drawing apparatus further comprises a calculating section to calculate the dose amount distribution information for the boundary region based on the information corresponding to the shape of the base material. 16. The pattern drawing apparatus of claim 14, wherein the drawing section comprises:an electronic beam emitting section to emit an electronic beam;an electronic lens to adjust a focus point of the electronic beam;a stand to support the base material; anda measuring section to measure a drawing position on the base material;wherein the control section controls the focus point of the electronic beam in accordance with the drawing position by adjusting an electric current of the electronic lens. 17. The pattern drawing apparatus of claim 14, wherein a difference between the fist dose amount and the second dose amount is a minimum adjustable dose amount based on a minimum clock of a D/A converter for driving an electronic beam gun for irradiating the electronic beam.