Method and device for patterning a disk
Embodiments of the invention relate to methods and apparatus useful in the nanopatterning of rotationally symmetric disk materials, like magnetic and optical disks, where a rotatable mask is used to image a radiation-sensitive material. Typically the rotatable mask comprises a cone. The nanopatterning technique makes use of Near-Field photolithography, where the mask used to pattern the disk is in contact or close proximity with the disk. The Near-Field photolithography may make use of an elastomeric phase-shifting mask, or may employ surface plasmon technology, where a rotating cone surface comprises metal nano holes or nanoparticles.
1. A method of patterning a disk comprising:
a) providing a disk having a radiation-sensitive layer on said disk;
b) providing a rotatable mask having a shape of a cone and a nanopattern on an exterior surface of said rotatable mask;
c) contacting said nanopattern with said radiation-sensitive layer on said disk;
d) distributing radiation through said nanopattern, while rotating said rotatable mask over said radiation-sensitive layer, whereby an image having a feature size less than 500 nm is created in said radiation-sensitive layer.
2. A method in accordance with claim 1 , wherein said nanopattern is a conformable nanopattern, which conforms to said radiation-sensitive layer on said disk.
3. A method in accordance with claim 2 , wherein said conformable nanopattern is a shaped or nanostructured polymeric material.
4. A method in accordance with claim 1 , wherein said rotatable mask is a phase-shifting mask which causes radiation to form an interference pattern in said radiation-sensitive layer.
5. A method in accordance with claim 1 , wherein said mask employs surface plasmon behavior.
6. A method in accordance with claim 1 , wherein said rotatable mask is a transparent cone, whereby radiation may be transmitted from a location interior of said cone.
7. A method in accordance with claim 6 , wherein said mask is a phase shifting mask which is present as a relief on a surface of said transparent cone.
8. A method in accordance with claim 6 , wherein said mask is a phase shifting mask which is present on a layer applied over a surface of said cone.
9. A method in accordance with claim 8 , wherein at least one nanopatterned film is applied to an exterior surface of said cone, whereby imaged feature dimensions in said radiation-sensitive layer more precisely represent prescribed feature dimensions.
10. A method in accordance with claim 1 , wherein said disk is kept in dynamic contact with said rotatable cone and rotated during distribution of radiation from the contact surface of said cone.
11. A method in accordance with claim 1 , wherein said rotatable mask and said disk are moved independently using a stepper-motor and a motorized disk rotational mechanism, and wherein movement of said rotatable mask and said disk surface are synchronized with each other, whereby a slip-free contact exposure of said radiation-sensitive layer is achieved.
12. A method in accordance with claim 1 wherein said nanopattern on an exterior surface of the cone is a fraction of a repetitive nanopattern created on the disk, obtained by more than one turns of said cone.