Patent Application
20090056575
Pattern transfer devices may be used to transfer a nano imprinted pattern from a patterned platen to a substrate. Due to the small size of components of the nano imprinted pattern being transferred, precise control of the transfer process may allow improved quality of the transferred pattern.
Platen 14 may be secured to platen support 12 by any method, such as vacuum pressure or adhesive, for example. Platen 14 may include a nano imprinted pattern 16 thereon, wherein pattern 16 may define a mirror image pattern of a plurality of micro electronic structures 18 (see
Apparatus 10 may further include a substrate support 20 that may support thereon a substrate 22, such as a silicon wafer, for example. Substrate 22 may include thereon a coating 24 that may be manufactured of a deformable material that may allow transfer of pattern 16 thereto from platen 14. Coating 24 may be manufactured of any material that may be suited to receive a pattern therein, such as a deformable material, or the like. Coating 24, as shown in
Substrate support 20 may include a cylinder 26 movable along an axis of movement 28 positioned perpendicular to a support surface 30 of substrate support 20. Movement of substrate support 20 may be controlled by a controller 32, such as a computer and/or pneumatic control valves, and motors 33, such as a piezoelectric motor, for example. In one embodiment, cylinder 26 may be moved toward platen 14 to position substrate 22 adjacent to but not in contact with platen 14, so as to ready substrate 22 for subsequent transfer of pattern 16 to substrate 22. In the figures shown, controller 32 and motors 33 are shown schematically. In one embodiment motors 33 may be located below base 60 and may move base 60 in the x, y and z directions.
Substrate support 20 may further include an inflatable membrane 34, such as a bladder, secured to cylinder 26. In one example embodiment, inflatable membrane 34 may be manufactured of silicon rubber and may be adhered with an epoxy to cylinder 26, which may be manufactured of metal. Inflatable membrane 34 may comprise one single membrane secured to cylinder 26 and therefore may define a contained inner cavity 36 therein. Inflatable membrane 34 may be connected by tubing 35 to a pressurization system 38, and thereby to controller 32, such that inflatable membrane 34 may be inflated to controllably move a top surface 40 of substrate 22, including coating 24, into contact with pattern 16 on platen 14. Pressurization system 38 may include tubing 39 that may extend through cylinder 26 and terminate adjacent a substrate 22 positioned on substrate support 20, so as to allow the application of vacuum pressure to a substrate 22 positioned on substrate support 20. In another embodiment, a single tubing system may be utilized to apply pressure to inflate/deflate membrane 34 and to cause movement of cylinder 26.
Inflatable membrane 34 may define a width dimension 42 that is smaller than a width dimension 44 of substrate 22 such that inflatable membrane 34 may contact and support only a portion of substrate 22. In an example embodiment wherein platen 14 and substrate 22 both define planar structures with a round perimeter, width dimensions 42 and 44 may define the diameter of the platen 14 and the substrate 22, respectively. In one example embodiment, inflatable membrane 34 contacts and supports substrate 22 only in a central region 46 thereof, wherein central region 46 defines approximately one half of a total surface area 48 of an underside 50 of substrate 22. Accordingly, as inflatable membrane 34 is inflated and moves substrate 22 into engagement with platen 14, substrate 22 may be unsupported by inflatable membrane 34 in an edge region 52 of substrate 22, and the edge region 52 of substrate 22 may be held on the outermost portion of base 60 by vacuum pressure within base 60, such that substrate 22 may bow slightly 53 in edge region 52 (see
Cylinder 26 may include a seal 56, such as an O-ring, that may define an air tight seal between cylinder 26 and a central aperture 58 of a base 60 through which cylinder 26 moves. Base 60 may include a sealing member 62 that may define a size and a shape so as to contact platen 14 (or platen support 12 in an embodiment wherein platen 14 has a width dimension 64 less than a width dimension 66 of sealing member 60) without contacting substrate 22. In one example embodiment, sealing member 62 may define an inflatable ring that may be connected by tubing 63 to pressurization system 38 and controller 32, such that sealing member 62 may be inflated to define a controlled atmosphere 68 between platen 14 and base 60. In one example method of transferring a pattern 16, controlled atmosphere 68 between platen 14 and base 60 may be purged of air and filled with a nitrogen gas, for example. After pattern 16 has been transferred to substrate 22, sealing member 62 may be deflated so as to allow removal of substrate 22 from substrate support 20.
Still referring to
The pressures utilized during one example embodiment of the present invention may range from twenty pounds per square inch (20 psi) to inflate inflatable membrane 34 or to move cylinder 26, down to a negative fourteen psi (−14 psi) vacuum to hold substrate 22 on substrate support 20. However, any pressures may be utilized for a particular application as may be applicable. The process may be conducted at ambient (room) temperature, or at other temperatures as may be desired.
Other variations and modifications of the concepts described herein may be utilized and fall within the scope of the claims below.
