Electron beam lithography method
View Patent ↗Deflecting means, for deflecting an electron beam in a radial direction and the circumferential direction, and blanking means, for shielding irradiation of the electron beam at portions other than drawing portions, are provided. While the disk is rotated unidirectionally, the electron beam is repeatedly deflected in a figure 8 pattern, in which the electron beam is deflected toward the next deflection initiation point in the radial direction at track edge portions, such that the deflected directions toward the inner periphery of the disk and toward the outer periphery of the disk intersect each other. Parallel scanning is performed alternately toward the outer periphery and the inner periphery of the disk. Elements of a transfer pattern, having lengths which are integer multiples of a reference value, are drawn by performing scanning a number of times equal to the integer that the reference value is multiplied by.
1. An electron beam lithography method, for drawing elements that constitute a transfer pattern of a master carrier for magnetic transfer, by: placing a disk, which has resist coated thereon, on a rotatable stage, which is also movable in the radial direction thereof; rotating the rotatable stage; and scanning an electron beam emitted from an electron beam lithography apparatus;
the transfer pattern comprising elements, which are formed within transfer regions of each sector of concentrically formed circumferential tracks and which have lengths in the circumferential direction that are integer multiples of a reference value;
the electron beam lithography apparatus comprising: deflecting means, for deflecting the emitted electron beam in the radial direction of the disk and also in the circumferential direction substantially perpendicular to the radial direction; and blanking means for shielding irradiation of the electron beam onto portions other than drawing portions;
the electron beam lithography method comprising the steps of:
unidirectionally rotating the disk;
repeating deflection of the electron beam in a figure 8 pattern, in which the electron beam is deflected toward the next deflection initiation point in the radial direction at track edge portions, such that the deflected directions toward the inner periphery of the disk and toward the outer periphery of the disk intersect each other;
scanning the electron beam alternately toward the inner peripheral portion and the outer peripheral portion of the rotating disk at a pitch equal to the reference value;
emitting the electron beam while operating the blanking means during deflection of the electron beam at the portions of the disk where the elements are drawn; and
drawing the elements, which have lengths that are integer multiples of a reference value, by scanning the electron beam in the radial direction a number of times equal to the integer that the reference value is multiplied by.
2. An electron beam lithography method as defined in claim 1 , wherein:
deflection of the electron beam in the radial direction is performed to be greater than a track width; and
deflection in the circumferential direction toward the radial direction to the next deflection initiation point is performed at a track edge portion outside the track width.
3. An electron beam lithography method as defined in claim 1 , wherein:
the angle between the deflection direction of the electron beam toward the outer peripheral direction and the deflection direction toward the inner peripheral direction is set according to the rotating speed of the disk, the angle of inclination of the element, and a drawing speed.
4. An electron beam lithography method as defined in claim 1 , wherein:
the reference value of the drawing length in the circumferential direction of the elements is defined by an oscillation width of the electron beam, when reciprocally oscillating the electron beam at high speed in the circumferential direction, which is substantially perpendicular to the radial direction of the disk.
5. An electron beam lithography method as defined in claim 1 , wherein:
the transfer pattern is a servo pattern that includes address portions.
6. An electron beam lithography method as defined in claim 2 , wherein:
the angle between the deflection direction of the electron beam toward the outer peripheral direction and the deflection direction toward the inner peripheral direction is set according to the rotating speed of the disk, the angle of inclination of the element, and a drawing speed.
7. An electron beam lithography method as defined in claim 2 , wherein:
the reference value of the drawing length in the circumferential direction of the elements is defined by an oscillation width of the electron beam, when reciprocally oscillating the electron beam at high speed in the circumferential direction, which is substantially perpendicular to the radial direction of the disk.
8. An electron beam lithography method as defined in claim 2 , wherein:
the transfer pattern is a servo pattern that includes address portions.
9. An electron beam lithography method as defined in claim 3 , wherein:
the reference value of the drawing length in the circumferential direction of the elements is defined by an oscillation width of the electron beam, when reciprocally oscillating the electron beam at high speed in the circumferential direction, which is substantially perpendicular to the radial direction of the disk.
10. An electron beam lithography method as defined in claim 3 , wherein:
the transfer pattern is a servo pattern that includes address portions.
11. An electron beam lithography method as defined in claim 4 , wherein:
the transfer pattern is a servo pattern that includes address portions.