WO2006066016A2 - Systems and methods for forming nanodisks used in imprint lithography and nanodisk and memory disk formed thereby - Google Patents

Systems and methods for forming nanodisks used in imprint lithography and nanodisk and memory disk formed thereby Download PDF

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Publication number
WO2006066016A2
WO2006066016A2 PCT/US2005/045458 US2005045458W WO2006066016A2 WO 2006066016 A2 WO2006066016 A2 WO 2006066016A2 US 2005045458 W US2005045458 W US 2005045458W WO 2006066016 A2 WO2006066016 A2 WO 2006066016A2
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WO
WIPO (PCT)
Prior art keywords
substrate
pattern
imprint
nanodisk
tracks
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Application number
PCT/US2005/045458
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French (fr)
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WO2006066016A3 (en
Inventor
Harry Sewell
Original Assignee
Asml Holding Nv
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Priority claimed from US11/012,474 external-priority patent/US7409759B2/en
Priority claimed from US11/012,598 external-priority patent/US7331283B2/en
Priority claimed from US11/012,489 external-priority patent/US7410591B2/en
Priority claimed from US11/224,316 external-priority patent/US7363854B2/en
Priority claimed from US11/288,135 external-priority patent/US7399422B2/en
Application filed by Asml Holding Nv filed Critical Asml Holding Nv
Priority to JP2007546900A priority Critical patent/JP4679585B2/en
Publication of WO2006066016A2 publication Critical patent/WO2006066016A2/en
Publication of WO2006066016A3 publication Critical patent/WO2006066016A3/en

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Classifications

    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/26Apparatus or processes specially adapted for the manufacture of record carriers
    • G11B7/261Preparing a master, e.g. exposing photoresist, electroforming
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B82NANOTECHNOLOGY
    • B82YSPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y10/00Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B82NANOTECHNOLOGY
    • B82YSPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00Manufacture or treatment of nanostructures
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03FPHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/0002Lithographic processes using patterning methods other than those involving the exposure to radiation, e.g. by stamping
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/84Processes or apparatus specially adapted for manufacturing record carriers
    • G11B5/855Coating only part of a support with a magnetic layer

Definitions

  • the present invention relates to imprint lithography.
  • a lithographic apparatus is a machine that applies a desired pattern onto a target portion of a substrate.
  • Lithographic apparatus are conventionally used, for example, in the manufacture of integrated circuits (ICs), flat panel displays and other devices involving fine structures.
  • An alternative for printing sub-lOOnm features comprises transferring a pattern to a substrate by imprinting a pattern into an imprintable medium using a physical mold or template.
  • the imprintable medium can be the substrate or a material coated on to a surface of the substrate.
  • the imprintable medium can be functional or can be used as a "mask" to transfer a pattern to an underlying surface.
  • the imprintable medium can, for example, be provided as a resist deposited on a substrate, such as a semiconductor material, to which the pattern defined by the template is to be transferred.
  • Imprint lithography is thus essentially a molding process on a micrometer or nanometer scale in which the topography of a template defines the patterns created on a substrate. Patterns can be layered as with optical lithography processes so that in principle imprint lithography could be used for such applications as IC manufacture.
  • imprint lithography is limited only by the resolution of the template fabrication process.
  • imprint lithography has been used to produce features in the sub-50 nm range with significantly improved resolution and line edge roughness compared to that achievable with conventional optical lithography processes.
  • imprint processes do not require expensive optics, advanced illumination sources, or specialized resist materials typically required by optical lithography processes.
  • Imprint lithography is being used to form memory disks or memory platens that adhere to an ever increasing requirement for very dense data bit formation.
  • forming denser data bits means each bit must be smaller and closer together. This closeness of the data bits can lead to data bits becoming unstable, either through thermal influences or outside magnetic influences (e.g., through superpara magnetism).
  • a conventional imprint mask used in nano-imprint technology is generally a quartz or hard surface plate that has been patterned and manufactured using an electron-beam (E-beam) lithography or ion beam lithography pattern writing system. After the required pattern has been written and an image developed in a layer of a resist, the pattern is transferred into the quartz or hard surface using an etch process. A shallow topography is formed in the quartz or hard surface that can be impressed into a plastic medium to give a pattern transfer.
  • E-beam electron-beam
  • Platens used in hard drives for data storage on computers comprise flat disks coated with a thin film of magnetic storage media.
  • a read/write head flies close to a surface of the platen, as it rotates, to transfer data from or to magnetic domains in a media film. Data is written into tracks which form concentric magnetic rings in the media.
  • An embodiment of the present invention provides a method of forming a nanodisk, comprising the following steps. Forming a first annular pattern comprising alternating sections of first and second materials. Imprinting the first annular pattern with a second pattern to form a cross hatched pattern on the first pattern. Selectively etching portions of the first and the second patterns on the nanodisk.
  • Another embodiment of the present invention provides a method of forming a wedge-shaped pattern comprising the following steps. Producing first and second materials using first and second thin film deposition sources. Alternating passage of the first and second materials through respective first and second shutters. Transmitting the fist and second materials using respective first and second openings of a deposition baffle. Rotating a substrate on an opposite side of the deposition baffle as the first and second deposition sources, the rotating substrate receiving the first and second materials to form successive layers of a boule. Removing sections of the boule to form the wedge-shaped pattern.
  • a further embodiment of the present invention provides a nanodisk for use in imprint lithography comprising tracks on a substrate and selectively etched areas proximate the tracks.
  • the selectively etched areas form data bit areas when the nanodisk is imprinted onto a memory platen.
  • a still further embodiment of the present invention provides a memory platen comprising main tracks, isolated data bits, and servo tracks.
  • the main tracks are formed by main tracks of a nanodisk.
  • the isolated data bits are formed by data bit areas on the nanodisk, the data bit areas of the nanodisk being located proximate the main tracks of the nanodisk.
  • the servo tracks are formed by servo tracks of the nanodisk, the servo tracks of the nanodisk being locating proximate one or more of the main tracks of the nanodisk.
  • a yet further embodiment of the present invention provides a method of manufacturing a memory disk.
  • Main tracks are formed on a disk platen.
  • Isolated bit areas are formed with respect to the main tracks on the disk platen.
  • a magnetic layer is formed on the isolated bit areas with magnetic material to form discrete isolated data bits.
  • the present invention includes a method for imprinting patterns formed on opposing surfaces of first and second imprint stamps onto first and second sides of a substrate, respectively.
  • the method includes deforming the surfaces of the first and second imprint stamps to produce respective first and second deformed surfaces, each having an arc therein.
  • a pressure is applied to bring the deformed first and second surfaces into intimate contact with the first and second substrate surfaces, respectively.
  • the applied pressure substantially flattens the deformed surfaces. And to separate the two surfaces from the respective surfaces of the substrate, the applied pressure is released.
  • the imprint apparatus of the present invention may print on both sides of a substrate, simultaneously.
  • the apparatus can employ, for example, two stamps, which are aligned to provide registration between top and bottom patterns.
  • the substrate is introduced between the two stamps and is aligned to them.
  • the apparatus has subsystems which provide positioning and alignment of Stamp A, Stamp B, and the substrate.
  • Substrate handling is provided.
  • Temperature and pressure monitoring system are provided.
  • X, Y, Z and tilt adjustments are provided for stamps and substrate.
  • the imprint apparatus may also be used to print one side of a substrate first and then print a second side of the substrate.
  • the stamps have induced bows in their surface to facilitate peel-off and stamp release from the substrate.
  • the imprint apparatus is used for producing patterned media for magnetic data storage. Tracks and Magnetic Domain patterns are aligned and printed on both sides of the data storage platens.
  • One or more embodiments of the present invention are applicable to any imprint lithography process in which a patterned template is imprinted into an imprintable medium in a flowable state, and, for example, can be applied to hot and UV imprint lithography as described above.
  • a system comprising a substrate, a carrier, and first and second imprint stamps.
  • the substrate has first and second patterning surfaces and a shaped edge.
  • the carrier has a holding portion that holds the shaped edge of the substrate.
  • the holding surface has a shape that is complementary to the shaped edge of the substrate, such that the patterning surfaces remain untouched by the carrier.
  • the first and second imprint stamps form patterns on respective ones of the first and second patterning surfaces.
  • the present invention includes a method for imprinting a pattern formed on a surface of an imprint mask into a substrate.
  • the method includes deforming at least one of the surface of the imprint mask and a surface of the substrate to produce a deformed surface having an arc therein.
  • a clamping pressure is applied to bring the deformed surface into intimate contact with the other surface, the applied pressure substantially flattening the deformed surface. To separate the two surfaces, the applied clamping pressure is released.
  • the present invention includes a method for manufacturing a nano-plate, for example.
  • the method includes depositing two or more types of film around a central core to form a plurality of film layers, each film layer being of a different type than its adjacent layers.
  • the deposited film layers are sectioned to expose a patterned surface.
  • the patterned surface is then planarized and selectively etched to expose patterns comprised of one of the types of film to a predetermined depth to produce a selectively etched surface.
  • This plate is then used as a stamp to impress an image of the circular tracks into a resin material.
  • the track pattern is transferred from the resin into the underlying disk material to form a hard drive platen.
  • the present invention includes a method for manufacturing a hard drive platen, for example.
  • the method includes depositing two or more types of film around a central core to form a plurality of film layers, each film layer being of a different type than its adjacent layers.
  • the deposited film layers are sectioned to expose a patterned surface.
  • the patterned surface is then polished and selectively etched to expose patterns comprised of one of the types of film to a predetermined depth to produce a selectively etched surface.
  • Magnetic material is deposited to fill resulting etched trenches.
  • the surface is then planarized to form a smooth surface with inlaid tracks of magnetic material.
  • the surface having the tracks of magnetic material is then planarized.
  • the present invention provides several solutions to enabling magnetic media to accommodate higher data storage density requirements. More specifically, the prevent invention provides a technique for creating a platen disk with physically separated tracks of magnetic media at line widths and pitch beyond the capabilities of either optical or electron beam lithography.
  • One exemplary approach for implementing the technique of the present invention is to physically separate the magnetic media into tracks that isolate the magnetic domains and form a physical structure for the read/write heads to follow.
  • Figures 1, 2, and 3 illustrate examples of conventional soft, hot and UV lithography processes, respectively.
  • Figure 4 illustrates a two-step etching process employed when hot
  • UV imprint lithography is used to pattern a resist layer.
  • Figure 5 schematically illustrates a template and a typical imprintable resist layer deposited on a substrate.
  • Figure 6 shows a view of a first pattern on a substrate, according to one embodiment of the present invention.
  • Figure 7 shows a view of a second pattern on a substrate, according to one embodiment of the present invention.
  • Figures 8 and 9 show top and perspective views, respectively, of overlapped first and second patterns in Figures 6 and 7, respectively, according to one embodiment of the present invention, for example when imprint is used for pattern transfer.
  • Figures 10 and 11 show views of the imprint stamp during and after an etching process, respectively, according to one embodiment of the present invention.
  • Figure 12 shows an imprint stamp after an etching process and removal of resist, according to one embodiment of the present invention.
  • Figure 13A is a cross-sectional view of a system used to form the second pattern shown in Figure 7, according to one embodiment of the present invention.
  • Figure 13B shows a portion of the system in Figure 13 A, according to another embodiment of the present invention.
  • Figure 14 is a view of a deposition baffle, according to one embodiment of the present invention.
  • Figure 15 shows a core for producing an imprint stamp having servo tracking patterns, according to one embodiment of the present invention.
  • Figure 16 is a view of patterns on an imprint stamp to produce servo tracking patterns, according to one embodiment of the present invention.
  • Figure 17 includes waveforms generated by a head reading servo tracking patterns, according to one embodiment of the present invention.
  • Figures 18 and 19 show flowcharts depicting various methods of practicing various embodiments of the present invention.
  • Figures 20, 21, 22, and 23 show various complementary shapes for substrate edge and carrier holding portions, according to various embodiments of the present invention.
  • Figure 24 is an illustration of an exemplary apparatus including two imprint stamps and a double-sided substrate arranged in accordance with an embodiment of the present invention.
  • Figure 25 is an illustration of the stamps and substrate illustrated in
  • FIG. 28 is an illustration of an exemplary apparatus including an imprint stamp and substrate arranged in accordance with an embodiment of the present invention
  • FIG. 29 is an illustration of the stamp and substrate illustrated in FIG.28 being exposed to ultra-violet (UV) radiation (UV exposure not required for thermal imprints);
  • FIG. 30 is an illustration of the stamp being separated from the resin in accordance with the present invention.
  • FIG. 31 is a flowchart of an exemplary method of practicing an embodiment of the present invention.
  • FIG. 32 is an illustration of an apparatus for making an imprint stamp in accordance with an embodiment of the present invention.
  • FIG. 33 is a more detailed illustration of a ring structure used within the apparatus illustrated in FIG. 32.
  • FIG. 34 is an illustration of an alternative to the ring structure of the apparatus shown in FIG. 32.
  • FIG. 35 is a cross-sectional portion of the ring structure illustrated in
  • FIG. 32 in accordance with an embodiment of the present invention
  • FIG. 36 is an illustration of another alternative to the ring structure of the apparatus shown in FIG. 32.
  • FIG. 37 is a flowchart of an exemplary method of practicing an embodiment of the present invention.
  • FIG. 38 is an illustration of an apparatus for making a computer hard drive platen in accordance with an embodiment of the present invention.
  • FIG. 39 is a more detailed illustration of a ring structure used within the apparatus illustrated in FIG. 38.
  • FIG. 40 is an illustration of an alternative to the ring structure of the apparatus shown in FIG. 38.
  • FIG. 41 is a cross-sectional portion of the ring structure illustrated in
  • FIG. 38 in accordance with an embodiment of the present invention.
  • FIG. 42 is an illustration of the cross-sectional portion of FIG. 41 having a magnetic media deposited in grooved sections in accordance with the present invention and after being planarized.
  • FIG. 43 is a flowchart of an exemplary method of practicing an embodiment of the present invention.
  • One or more embodiments of the present invention provide a system and method to form a memory disk having isolated data bits, for example using imprint lithography.
  • the imprint stamp is formed from first and second overlapping patterns, where the patterns are selectively etched. The selective etching leaves either pits or posts on the imprint stamp.
  • the pits or posts are imprinted on the memory disk, leaving either pits or posts on the memory disk.
  • the pits or posts on the memory disk are processed to form relatively small and dense isolated data bits. Instability of the isolated data bits caused by outside magnetic and thermal influences is substantially eliminated.
  • FIG. 1 shows the soft lithography process that involves transferring a layer of molecules 11 (typically an ink such as a thiol) from a flexible template 10 (typically fabricated from polydimethylsiloxane (PDMS)) onto a resist layer 13 that is supported upon a substrate 12 and planarization and transfer layer 12 ⁇
  • the template 10 has a pattern of features on its surface, the molecular layer being disposed upon the features.
  • the layer, of molecules 11 stick to the resist.
  • the layer of molecules 11 stick to the resist and the residual layer of resist is etched, such that the areas of the resist not covered by the transferred molecular layer are etched down to the substrate.
  • the template used in soft lithography can be easily deformed and can therefore not be suited to high-resolution applications, e.g., on a nanometer scale, since the deformation of the template can adversely affect the imprinted pattern. Furthermore, when fabricating multiple layer structures, in which the same region will be overlaid multiple times, soft imprint lithography may not provide overlay accuracy on a nanometer scale.
  • Hot imprint lithography is also known as nanoimprint lithography (NIL) when used on a nanometer scale.
  • NIL nanoimprint lithography
  • the process uses harder templates made from, for example, silicon or nickel, which are more resistant to wear and deformation. This is described, for example, in U.S. Patent No. 6,482,742 and illustrated in Figure 2 of the instant application.
  • a solid template 14 is imprinted into a thermosetting or a thermoplastic polymer resin 15, which has been cast on the surface of a substrate 12.
  • the resin can, for example, be spin coated and baked onto the substrate surface or more typically (as in the example illustrated) onto a planarization and transfer layer 12'.
  • hard when describing an imprint template includes materials that can generally be considered between “hard” and “soft” materials, such as for example "hard” rubber. The suitability of a particular material for use as an imprint template is determined by its application requirements.
  • thermosetting polymer resin When a thermosetting polymer resin is used the resin is heated to a temperature such that, upon contact with the template, the resin is sufficiently flowable to flow into the pattern features defined on the template. The temperature of the resin is then increased to thermally cure (e.g., crosslink) the resin so that it solidifies and irreversibly adopts the desired pattern. The template can then be removed and the patterned resin cooled.
  • thermally cure e.g., crosslink
  • thermoplastic polymer resins used in hot imprint lithography processes are poly (methyl methacrylate), polystyrene, poly (benzyl methacrylate) or poly (cyclohexyl methacrylate).
  • the thermoplastic resin is heated so that it is in a freely flowable state immediately prior to imprinting with the template. It is typically necessary to heat thermoplastic resins to temperatures considerably above the glass transition temperature of the resin.
  • the template is pressed into the flowable resin and sufficient pressure is applied to ensure the resin flows into all the pattern features defined on the template.
  • the resin is then cooled to below its glass transition temperature with the template in place whereupon the resin irreversibly adopts the desired pattern.
  • the pattern will consist of the features in relief from a residual layer of the resin that can then be removed by an appropriate etch process to leave only the pattern features.
  • a two-step etching process is performed as illustrated in Figure 4.
  • the substrate 20 has a planarization and transfer layer 21 upon it, as shown in step a.
  • the purpose of the planarization and transfer layer is twofold. It acts to provide a surface parallel to that of the template, which is important to ensure that the contact between the template and the resin is parallel, and also to improve the aspect ratio of the printed features, as will be described below.
  • a residual layer 22 of the solidified resin is left on the planarization and transfer layer, shaped in the desired pattern.
  • the first etch is anisotropic and removes parts of the residual layer, resulting in a high aspect ratio of features where Ll is the height of the features 23, as shown in step b.
  • the second etch is anisotropic (or selective) and further improves the aspect ratio.
  • the anisotropic etch removes those parts of the planarization and transfer layer which are not covered by the solidified resin, increasing the aspect ratio of the features 23 to (L2/D), as shown in step c.
  • the resulting polymer thickness contrast left on the substrate after etching can be used as, for example, a mask for dry etching if the imprinted polymer is sufficiently resistant, for example, as a step in a lift-off process.
  • Hot imprint lithography suffers from a disadvantage in that not only is the pattern transfer to be performed at a higher temperature, but also relatively large temperature differentials might be required in order to ensure the resin is adequately solidified before the template is removed. Temperature differentials between about 35 and about 100 0 C are known from literature. Differential thermal expansion between, for example, the substrate and template, can then lead to distortion in the transferred pattern.
  • UV imprint lithography does not involve such high temperatures and temperature changes. Nor does it require such viscous imprintable materials. Rather UV imprint lithography involves the use of a transparent template and a UV-curable liquid, typically a monomer such as an acrylate or methacrylate for example. In general any photopolymerisable material could be used, such as a mixture of monomers and an initiator.
  • the curable liquid can also, for example, include a dimethyl siloxane derivative.
  • Such materials are much less viscous than the thermosetting and thermoplastic resins used in hot imprint lithography and consequently move much faster to fill template pattern features. Low temperature and low pressure operation also favors higher throughput capabilities.
  • FIG. 3 An example of a UV imprint process is illustrated in Figure 3.
  • a quartz template 16 is applied to a UV-curable resin 17 in a similar manner to the process of Figure 4.
  • UV light is applied to the resin through the quartz template in order to polymerize and thus cure it.
  • the remaining steps of etching the residual layer of resist are the same as for the hot embossing process described above.
  • the UV curable resins typically used have a much lower viscosity than typical thermoplastic resins so that lower imprint pressures can be used.
  • UV imprint lithography improves suited to applications requiring high overlay accuracy.
  • transparent nature of UV imprint templates can accommodate optical alignment techniques simultaneously to the imprint.
  • UV imprint lithography mainly uses UV curable materials, and is thus genetically referred to as UV imprint lithography
  • other wavelengths of light can be used to cure appropriately selected materials (e.g., activate a polymerization or cross-linking reaction).
  • any radiation capable of initiating such a chemical reaction can be used if an appropriate imprintable material is available.
  • Alternative "activating light” can, for example, include visible light, infrared light, x-ray radiation, and electron beam radiation.
  • references to UV imprint lithography and use of UV light are not intended to exclude these and other activating light possibilities.
  • roller imprint systems As an alternative to imprint systems using a planar template that is maintained substantially parallel to the substrate surface, roller imprint systems have been developed. Both hot and UV roller imprint systems have been proposed in which the template is formed on a roller, but otherwise the imprint process is very similar to imprinting using a planar template. Unless the context requires otherwise, references to an imprint template include references to roller templates.
  • step and flash imprint lithography SFIL
  • step and flash imprint lithography This involves printing small areas of the substrate at a time by imprinting a template into a UV curable resin, 'flashing' UV light through the template to cure the resin beneath the template, removing the template, stepping to an adjacent region of the substrate and repeating the operation.
  • the small field size of such step and repeat processes minimizes pattern distortions CD variations so that SFIL is particularly suited to manufacture of IC and other devices requiring high overlay accuracy.
  • the UV curable resin can be applied to the entire substrate surface, for example, by spin coating, this is problematic due to the volatile nature of UV curable resins.
  • One approach to addressing this problem is the so-called 'drop on demand' process in which the resin is dispensed onto a target portion of the substrate in droplets immediately prior to imprinting with the template. The liquid dispensing is controlled so that a certain volume of liquid is deposited on a particular target portion of the substrate. The liquid can be dispensed in a variety of patterns and the combination of carefully controlling liquid volume and placement of the pattern can be employed to confine patterning to the target area.
  • the size and spacing of the droplets are carefully controlled to ensure there is sufficient resin to fill template features, while at the same time minimizing excess resin which can be rolled to an undesirably thick or uneven residual layer since as soon as neighboring drops touch fluid the resin will have nowhere to flow.
  • the problems associated with overly thick or uneven residual layer are discussed below.
  • Figure 5 illustrates the relative dimensions of the template, imprintable material (e.g., curable monomer, thermosetting resin, thermoplastic, etc) and substrate.
  • the ratio of the width of the substrate, D, to the thickness of the curable resin layer, t is of the order of about 106. It will be appreciated that, in order to avoid the features projecting from the template damaging the substrate, the dimension t should be greater than the depth of the projecting features on the template.
  • the residual layer left after stamping is useful in protecting the underlying substrate, but as mentioned above it is also the source of a number of problems particularly when high resolution and/or overlay accuracy is desired.
  • the first 'breakthrough' etch is anisotropic, but non-selective, and can to some extent erode the features imprinted as well as the residual layer. This is exacerbated if the residual layer is overly thick and/or uneven.
  • the above problem can be reduced by ensuring the residual layer is as thin as possible, but this can require application of undesirably large pressures (e.g., increasing substrate deformation) and relatively long imprinting times (e.g., reducing throughput).
  • undesirably large pressures e.g., increasing substrate deformation
  • relatively long imprinting times e.g., reducing throughput
  • the template is a significant component of the imprint lithography system. As noted above, the resolution of the features on the template surface is a limiting factor on the attainable resolution of features printed on the substrate.
  • the templates used for hot and UV lithography are generally formed in a two-stage process. Initially, the desired pattern is written using, for example, electron beam writing, to give a high-resolution pattern in resist. The resist pattern is then transferred into a thin layer of chrome which forms the mask for the final, anisotropic etch step to transfer the pattern into the base material of the template.
  • the release characteristics of the template can also be an important consideration.
  • the template can, for example, be treated with a surface treatment material to form a thin release layer on the template having a low surface energy (a thin release layer can also be deposited on the substrate).
  • imprint apparatus and methods described can have other applications, such as the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, hard disc magnetic media, flat panel displays, thin-film magnetic heads, etc.
  • the unprintable material can itself be a functional material, for example, having a functionality such as conductivity, optical linear or non linear response amongst others.
  • the functional material can form a conductive layer, a semiconductive layer, a dielectric layer or a layer having another desirable mechanical, electrical or optical property.
  • Some organic substances can also be appropriate functional materials. Such applications can be within the scope of an embodiment of the present invention.
  • Figure 6 shows a view of a first pattern 600 on a substrate (not specifically shown) to begin forming a nanodisk (not shown), according to one embodiment of the present invention.
  • the nanodisk can be an imprint stamp, a memory disk, or the like.
  • First pattern 600 (e.g., a first layer) formed on the substrate comprises a first material 602 (shown as light circles) and a second material 604 (shown as dark circles).
  • first and second materials 602 and 604 are formed as alternating layers and are formed annularly around a core 606 to form a boule, for example as described in U.S. Appl. Nos. 11/012,474 and 11/012,489 discussed above, hi one example, first material 602 is silicon dioxide and second material 604 is silicon nitride. It is to be appreciated that other materials can also be used, hi some examples, first pattern 600 is referred to as a track, master track, defined track, or the like.
  • Figure 7 shows a view of a second pattern 710 (e.g., second layer) on a substrate, according to one embodiment of the present invention.
  • second pattern 710 is formed as a radial pattern.
  • Second pattern 710 is formed from a first material 702 (shown as dark lines) and a second material 704 (shown as light lines).
  • first and second materials 702 and 704 are formed as alternating layers.
  • first material 702 is silicon dioxide and second material 704 is silicon nitride.
  • second pattern 710 can be formed using the system shown in Figures 13A, 13B, and 14, as described in more detail below.
  • second pattern 710 can be formed from first and second pattern portions 710A and 710B.
  • second pattern 710 can be formed from a single portion 710. Both of these embodiments are described in more detail below (hereinafter, both embodiments are shown and discussed as a single portion 710 for convenience, but not by limitation).
  • Figure 8 show a view of overlapping of the first pattern 600 of Figure 6 with second pattern 710 in Figure 7 used to form the nanodisk, according to one embodiment of the present invention.
  • first and second patterns 600 and 710 are not drawn to scale.
  • second pattern 710 is smaller in overall size than first pattern 600, so multiple second patterns 710 are formed on first pattern 600, for example in a radial manner.
  • only one of second pattern 710 is fully shown overlapping first pattern 600, while the other ones of second pattern 710 are only shown in outline.
  • a Crosshatch pattern 812 is formed.
  • second pattern 710 is formed on first pattern 600 using known pressure, temperature, and timing methods, as would be known to skilled artisans, such that second pattern 710 is coupled to first pattern 600, or the like.
  • second pattern 710 is imprinted onto resist coating first pattern 600 quadrant by quadrant using second pattern 710 as a stamp. In one example, this can be done using imprint lithography techniques. In one example, alignment techniques can be used to align each imprinting of second pattern 710 onto first pattern 600 to form cross hatch pattern 812. This imprint method of forming cross-hatch pattern 812 is discussed in more detail below.
  • Figure 9 shows a view of the nanodisk during processing, according to one embodiment of the present invention. This view of the nanodisk is before residual resist in areas 913, which are spaces between resist areas 915, are etched away. Resist areas 915 are formed from imprinting second pattern 710 onto a resist layer formed on first pattern 600.
  • Figures 10 and 1 1 show views of the nanodisk during and after an etching process, respectively, according to one embodiment of the present invention.
  • this view is after residual resist is etched from areas 913, leaving only resist at areas 915. Areas 1014 of first material 602 are exposed between resist areas 915, while areas 1017 of second material 604 are still covered by resist 915.
  • areas 1014 are etched to form holes or pits
  • first material e.g., silicon dioxide
  • areas 1116 can be holes, pits, or the like in first pattern 600 of the imprint stamp.
  • the areas 1014 to be etched can be defined where the pattern formed from the first material 702 of the second pattern 710 overlaps the first material 602 of the first pattern 600.
  • areas 1017 are shown, which, as discussed and shown with respect to Figure 12, form tops of posts 1218.
  • areas 1116 when the nanodisk including areas 1116 is used in imprint lithography to imprint a pattern on a surface of a disk (not shown) or on a coating of the surface of the disk (e.g., a resin or the like), areas 1116 form posts or extending mesa structures on the surface of the memory disk that extend from the memory disk. These posts or extending mesa structures are later processed so that they comprise magnetic material that is used as a data bit (e.g., coated with a magnetic material). In one example, these posts or extending mesa structures on the memory disk are isolated "island" like structures. This allows for isolated data bit areas that are relatively small and dense to be formed on the memory disk, while allowing the data bits to remain stable, based on their isolation from each other, when influenced by outside thermal and magnetic affects.
  • Figure 12 shows the nanodisk after an additional etching process has been done to the nanodisk shown in Figure 11 , according to one embodiment of the present invention.
  • This additional etching process is only performed if desired for a particular final arrangement of the nanodisk.
  • an additional etching step subsequent to that shown in Figure 11 is performed to remove the resist 915 and at least a portion of second material 604 (e.g., silicon nitride) of first pattern 600, which was not initially selectively etched in Figure 11.
  • This additional etching step can be used to produce a nanodisk that includes posts or mesa structures 1218, which have top surfaces 1017, which extend from the nanodisk adjacent holes or pits 1116.
  • first pattern 600 is used to produce tracks on the memory disk and posts 1218 can be used with either a UV-cure Resin or Thermal Resist to imprint vias or holes into the memory disk proximate the tracks. These vias or holes are then partially filled with magnetic material to form isolated data bits. Based on their isolation, the data bits formed in the vias or holes will remain stable when influenced by outside thermal and magnetic effects.
  • Figure 13A is a cross-sectional view of a system 1318 that is used to form second pattern 710, according to one embodiment of the present invention.
  • Figure 14 is a view of a deposition baffle of the system of claim 13A, according to one embodiment of the present invention.
  • system 1318 comprises a substrate 1320 releaseably secured to a rotating carousel 1322, or any other device that can rotate substrate 1320.
  • a first source 1324 deposits first material 702 onto substrate 1320 after first material 702 passes through a shutter 1326 and an opening 1328 in a deposition baffle 1330 (see also Figure 14 for a top view of deposition baffle 1330).
  • a second source 1332 deposits second material 704 onto substrate 1320 after second material 704 passes through a shutter 1334 and an opening 1336 in deposition baffle 1330.
  • first and second source 1324 and 1332 are thin film deposition sources that operate during alternative time periods utilizing shutters 1326 and 1334.
  • a pie-shaped or wedge-shaped nanodisk base structure is produced to produce a pattern, such as pattern 710 shown in Figure 7. This is accomplished by depositing successive layers of first and second materials 702 and 704 onto substrate 1320 while it is being rotated by rotating carousel 1322 to produce a toroid (e.g., donut) shaped boule 1338. Boule 1338 can then be diamond sawn and have the sawn sections polished. These sawn and polished sections comprise the pie-shaped stamp base structure.
  • the pie-shaped stamp base structure comprises a flat surface with striations of first and second materials 702 and 704 to form first and second portions 710A and 710B of second pattern 710, as shown in Figure 7.
  • the pie shape is produced by having reduced deposition rates of first and second materials 702 and 704 at one end of boule 1338 compared to another end of boule 1338.
  • deposition baffle 1330 can be used to control the deposition rate in conjunction with rotating carrousel 1322. This causes the deposition rate for first and second materials 702 and 704 to be highest closest to the center e.g., at positions 1340 and 1342, of the carrousel 1322 holding the boule 1338 and to be slowest at the edges, e.g., at positions 1344 and 1346, of the carousel 1322 holding the boule 1338.
  • Figure 13B shows a portion of the system in Figure 13 A, according to another embodiment of the present invention.
  • substrate 1320' has a sloped material receiving surface 1339.
  • first and second materials 702 and 704 are deposited on substrate 1320', as discussed above, a boule 1338' is formed that, when cut and polished, forms pattern 710 from a single portion, and not a double portion as discussed above with regards to Figure 13 A.
  • the above-described method of fabricating the nanodisk allows for almost unlimited resolution of a pattern formed on a memory disk by the nanodisk. For example, line/space resolutions of 9nm have been achieved for basic tracks formed by similarly produced nanodisks when used in imprint lithography to pattern a memory disk. In one example, discrete islands of 9nm by 9nm are thought to be possible, while other resolutions significantly below this may also be possible.
  • a memory disk generated with the above nanodisk formed using the systems and methods described, for example, in Figures 6-14 typically can comprise both data bit tracks, which include the data bits described above, and can also include servo tracking patterns used to guide tracking of a head or heads (e.g., read/write head(s)) over the data bit tracks.
  • These servo tracking patterns usually consist of a set of bits offset from set of data bits associated with the track.
  • the servo tracking pattern of the offset bits is predetermined and is shaped so that as the head (or heads) pass over the offset bits, the position of a servo head with respect to a center of a track including the data bits can be monitored.
  • Figure 15 shows a core 1506 having grooves 1550, according to one embodiment of the present invention.
  • Figure 16 is a view of patterns on a nanodisk or imprint stamp to produce servo tracking patterns, according to one embodiment of the present invention.
  • core 1506 can be used to receive first and second materials 602 and 604 and then sliced to form an alternative first pattern 1600 of an imprint stamp or nanodisk.
  • Pattern 1600 is altered compared to first pattern 600 shown in Figure 6 because grooves 1550 forms a "wobble" in the pattern, as discussed below.
  • the servo tracking pattern 1600 on an imprint stamp or nanodisk can be used in imprint lithography to form servo tracks and data bit tracks, respectively, on a memory disk, for example.
  • a cluster of grooves 1550 is formed in a surface of a core 1506 (e.g., a quartz rod). Groves 1550 are formed at regular intervals around a circumference of core 1506 in such a way as to put a displacement into a radius of pattern 1600 that forms tracks on a memory disk. As the pattern 1600 is built up with successive layers, the displacement in what will become a track position on the memory disk is translated through all layers. For example, this displacement can be a pre-programmed "wobble" that can be changed into an AC signal that can be read and interpreted by a head to indicate whether a head is moving off right or off left of a desired data bit track position.
  • Figure 17 shows waveforms 1752-1756 generated by a head reading servo tracking patterns formed on a memory disk using pattern 1600, according to one embodiment of the present invention.
  • the head when a head passes over a pattern cluster including servo tracking patterns on the memory disk formed by pattern 1600, the head will generate an amplitude modulation at a frequency related to rotation speed of the memory disk and the spacing of the data bits tracks formed on the memory disk using pattern 1600 on the imprint stamp during imprint lithography.
  • This servo tracking signal can be monitored to adjust a position of the head during reading of the data bits.
  • the head is centered when a signal is maximized and when a signal frequency is doubled, as shown in waveform 1756.
  • a phase of the signal generated by the head from reading the offset bits in the servo tracking pattern on the memory disk indicates whether the head is to the inside or to the outside of the data bit track radius.
  • waveform 1752 is detected when the head is to the right of the track 1550 and waveform 1754 is detected when the head is to the left of the track 1550.
  • a servo actuator system would receive the signals from the head and actuate movement of the head based on the signals, as would be known to a skilled artisan.
  • the servo actuator system can be a learning system that saves data of historical misalignments for future adjustment.
  • hard drive platens e.g., memory disks
  • the hard drive platen zones are tracks with varying radii. For example, an inner zone, a mid zone, and an outer zone can have a gap between the zones in terms of track positions. Then, each of the zones are divided up into sectors, like pie-shaped pieces, and the beginning and end of each sector has various read- write control data bits, which allow, for example, the amplitude of the signal to be automatically adjusted, position of the head to be adjusted.
  • the zones may also have markers that indicate a beginning or an end of where the data is programmed in the platen.
  • the hard drive platens are not necessarily a continuous a continuous array of data bits, rather they comprise a format structure.
  • an interference imager using two coherent light beams that are converged together in a fluid using immersion to form an interference grating type image on a substrate may be used to print tracks on a memory disk.
  • FIG 18 shows a flowchart depicting a method 1800 for forming a nanodisk having areas used to pattern data bit areas on a memory disk using imprint lithography, according to one embodiment of the present invention.
  • a first annular pattern is formed that comprises alternating sections of first and second materials.
  • the first annular pattern is imprinted with a second pattern to form a cross hatched pattern on the first pattern.
  • portions of the first and the second patterns on the nanodisk are selectively etched.
  • FIG. 19 shows a flowchart depicting a method 1900, according to one embodiment of the present invention.
  • method 1900 can be a method of manufacturing a memory disk.
  • main tracks are formed on a disk platen.
  • isolated bit areas are formed with respect to the main tracks on the disk platen.
  • a magnetic layer is formed on the isolated bit areas with magnetic material to form discrete isolated data bits.
  • step 1904 pits are formed in the disk platen and in step 1906 the magnetic material is deposited in the pits to form the discrete isolated data bits.
  • step 1904 posts are formed on the disk platen and in step 1906 the posts are coated with the magnetic material to form the discrete isolated data bits.
  • step 1908 servo tracks are formed on the disk platen, the servo tracks being located proximate one or more of the main tracks.
  • FIG. 20 shows a portion of an imprint lithography system, according to one embodiment of the present invention.
  • a carrier 2000 is used to transport a substrate 2002 from one location of a lithography tool (not shown), e.g., an imprint lithography tool, to another location of the lithography tool.
  • substrate 2002 can be transported for patterning, as is described in more detail above and below.
  • substrate 2002 includes first and second resin surfaces 2004 and 2006, which can both be patterning surfaces.
  • substrate 2002 is contacted on its edge 2008 by holding portions 2010 of carrier 2000.
  • a shape of edge 2008 is formed to be complementary with a shape of holding portion 2010, while allowing for edge 2008 to be supported by holding portions 2010.
  • Various exemplary shapes are shown in Figure 21, 22, and 23 below.
  • Figures 21, 22, and 23 show various complementary shapes for substrate edge 2108 and carrier holding portions 2010, according to various embodiments of the present invention. These are meant to be exemplary, and not exhaustive.
  • Figure 21 shows a substrate 2102 having a single beveled edge 2108 being held by a holding portion 2110 of a carrier 2100 having a complementary single beveled shape, such that carrier 2100 does not touch patterning surfaces
  • Figure 22 shows a substrate 2202 having a double beveled edge 2208 being held by a holding portion 2210 of a carrier 2200 having a complementary double beveled shape, such that carrier 2200 does not touch patterning surfaces
  • Figure 23 shows a substrate 2302 having a stepped edge 2308 being held by a holding portion 2310 of a carrier 2300 having a complementary stepped shape, such that carrier 2300 does not touch patterning surfaces 2304 and 2306 during transport.
  • a curvature or bow is created in the imprint stamp that allows the stamp to be separated from the resin (substrate) with an unzipping action. Once separated from the stamp, the substrate can be unloaded from the apparatus in an undamaged state.
  • the curvature or bow is instrumental in providing a clean separation of the stamp and substrate, particularly on larger substrates.
  • FIG. 24 is an illustration of an exemplary apparatus 2400 including imprint stamps 2402a/2402b and a double sided substrate (e.g., a resin coated patterned media disc substrate) 2404, arranged in accordance with an embodiment of the present invention.
  • the substrate 2404 can be held in place, for example, by a patterned media carrier plate 2405.
  • the imprint stamps 2402a and 2402b can be nano-plate imprint stamps (i.e., having nano-scale features on the orders of several nanometers line width), although other types of imprint stamps can be used.
  • the imprint stamps 2402a and 2402b respectively include patterns
  • each of the imprint stamps 2402a and 2402b is clamped in such a way as to create a bow in the stamp profile.
  • the imprint stamps 2402a and 2402b are held by a vacuum seal 2406 against vacuum lands 2407 that are out of planar.
  • Deviation 2408 from planar is quite small, but is sufficient to deviate a center portion 2410 of the stamps 2402a and 2402b, many microns out of flat.
  • This bow or curvature which has been introduced in the stamp, ensures that when each of the stamps 2402a and 2402b and the respective sides 2404a/2404b of the substrate 2404 are brought together, it is the center portion 2410 of the stamps 2402a and 2402b that makes contact with respective sides 2404a/2404b of the substrate 2404, first.
  • stamps 2402a and 2402b can be clamped flat onto substrate 2404 and the bowing can be produced by gas pressure (e.g., air or nitrogen) being exerted behind a plate of each of the stamps 2402a and 2402b to release stamps 2402a and 2402b from substrate 2404.
  • gas pressure e.g., air or nitrogen
  • the bow introduced in stamp 2402a is substantially equal to the bow introduced in stamp 2402b.
  • the amount of bowing can be different in each stamp.
  • the substrate 2404 has a bore
  • Respective alignment markers 2414a and 2414b are provided as reference points for precisely aligning each of the stamps 2402a and 2402b respectively, to the center bore 2412 of the substrate 2404.
  • a positioning and alignment system 2416 can then be used to perform the actual alignment of the markers 2414a and 2414b to the bore 2412. Alignment can be accomplished, for example, by first aligning the marker 2414a with the marker 2414b. Next, the bore 2412 can be aligned with the previously aligned markers 2414a and 2414b.
  • the positioning and alignment system 2416 can be selected from a number of different lithography alignment tools.
  • alignment can be performed based on alignment marks 2418a-d, where alignment is made between alignment marks 2418a and 2418b and between 2418c and 2418d.
  • a viewing system can then be used to view the alignment markers 2414 and the bore 2412 during the alignment process.
  • FIG. 25 is an illustration 2500 of the stamps 2402a/2402b and the substrate 2404, shown in FIG. 24.
  • the stamps 2402a/2402b and the substrate 2404 are shown under application of force 2502 and exposure to optional ultra-violet (UV) radiation 2504. That is, during an actual imprinting procedure, the stamps 2402a/2402b and respective sides of the substrate 2404, are simultaneously pressed together with enough force 2502 to conform the side 2404a to the stamp 2402a and the 2404b to the stamp 2402b, together in intimate contact.
  • the applied force or pressure can result from a vacuum, hydraulic, pneumatic means, electrostatic, electromagnetic, or by a combination of some or all of these techniques.
  • the bows formed in each of the stamps 2402a and 2402b are substantially flattened out by a clamping pressure. Further clamping pressure can be applied using the vacuum seals 2414.
  • the vacuum seals are provided to create a vacuum cavity between the sides of substrate 2404 and the imprint stamps 2402a and 2402b, respectively.
  • the pressure and temperature of the stamping process is controlled to provide high quality pattern transfer.
  • the entire apparatus is enclosed in a chamber which provides temperature control.
  • the temperature of the apparatus including the substrate is controlled to a temperature defined by the requirements of the process conditions of the applied resin.
  • Transfer of the patterns 2403 a and 2403b into the respective sides 2404a and 2404b can be further facilitated by optionally flood exposing, for example, a UV-cure type resin with UV light 2504 through each of the imprint stamps 2402a and 2402b and into the sides of the substrate 2404, respectively.
  • the UV exposure 2504 cross-links the resin coated substrate 2404 and helps to solidify the resin.
  • FIG. 25 provides an illustration of a UV-curable resin coated substrate
  • the present invention is not limited to this approach.
  • the principle of deforming the imprint stamps 2402a and 2402b with an arc or bow is also applicable using a thermal resin. With thermal resin, the substrate and imprint mask are brought together at an elevated temperature which is sufficient to soften the resin.
  • stamps 2402a and 2402b can be physically pressed into the resin supplied to substrate 2404 by applying the force/pressure 2502.
  • a thermal resin no U-V exposure is required to cure the resin.
  • Both the stamps 2402a and 2402b, and the substrate 2404 are typically heated and temperature controlled in the case of thermal imprinting.
  • FIG. 26 is an illustration 2600 of the imprint stamps 2402a and 2402b being separated from the sides of the substrate 2404, in accordance with an embodiment of the present invention.
  • the release of the vacuum and reduction of the pressure 2502 between the stamps 2402a and 2402b and the sides initiates the separation process.
  • the imprint stamp 2402a begins to separate from the first substrate side and the imprint stamp 2402b begins to separate from the second substrate side. This separation begins first as a peeling apart at the outer edge 2602a - 2602d.
  • the imprint stamps 2402a and 2402b are held by a vacuum seal 2406 against vacuum lands 2407 that are out of planar.
  • stamps 2402a and 2402b have central apertures in them. A ball or curvature is introduced in these stamps 2402a/2402bto facilitate separation between stamps 2402a/2402b and substrate 2404.
  • stamps 2402a/2402b can be, but are not limited to, square or disk shaped.
  • the substrate 2404 in a carefully controlled manner as the pressure is fully released. There is an unzipping, or peeling back action, as opposed to a straight pull off, to separate the sides 2404a and 2404b from the imprint stamps 2402a and 2402b, respectively. This action is essential to the keeping of nanometer sized imprinted patterns transferred to the substrate 2404 in place and undamaged. Once separated from the imprint stamp 2402a and 2402b, the substrate 2404 can be unloaded from the apparatus 2600.
  • FIG. 27 is a flowchart of an exemplary method 2000 of practicing an embodiment of the present invention.
  • first and second surfaces of an imprint stamp are deformed to produce respective first and second deformed surfaces, each having an arc therein, as indicated in step 2702.
  • step 2704 a pressure is applied to bring the deformed first and second surfaces into intimate contact with first and second substrate surfaces respectively, the applied pressure substantially flattening the deformed surface. To separate the two surfaces, the applied pressure is released, as indicated in step 2706.
  • the patterning of the first and second sides of the substrate is performed substantially simultaneously.
  • a curvature or bow is created in the imprint stamp that allows the stamp to be separated from the resin with an unzipping action. Once separated from the stamp, the substrate can be unloaded from the apparatus undamaged.
  • the curvature or bow is instrumental in providing a clean separation of the stamp and substrate particularly on large substrates.
  • FIG. 28 is an illustration of an exemplary apparatus 2800 including an imprint stamp 2802 and a substrate (e.g., a resin) 2804 arranged in accordance with an embodiment of the present invention.
  • the imprint stamp 2802 can be, for example, a nano-plate imprint stamp (i.e., having nano-scale features on the orders of a few hundreds of millimeters line width).
  • the imprint stamp 2802 includes a pattern that is to be printed onto the substrate 2804.
  • the use of vacuums is well know in the semiconductor manufacturing art.
  • the imprint stamp 2802 is fastened onto a mask holder platen 2803 using vacuum lands 2806.
  • the imprint stamp 2802 is fastened onto the mask holder platen 2803 in such a way as to create a bow in the stamp profile.
  • the imprint stamp 2802 is held by vacuum against vacuum lands that are out of planar. Deviation 2808 from planar is quite small, but is sufficient to deviate a center portion 2810 of the stamp 2802 many microns out of flat.
  • This bow or curvature which has been introduced in the stamp, ensures that when the stamp 2802 and the substrate 2804 are brought together, it is the center portion 2810 of the stamp 2802 that makes contact with the substrate 2804 first.
  • the substrate 2804 which is to be impressed, is mounted onto a substrate platen 2812.
  • the substrate platen 2812 need not be flat. That is, the substrate platen 2812 can also have a bow built into it which will also allow the central region of the substrate 2804 to meet the central portion 2810 of the stamp 2802 first.
  • FIG. 29 is an illustration 2900 of the stamp 2802 and the substrate 2804, shown in FIG. 28, being exposed to ultra-violet (UV) radiation 2902. That is, the pattern transfer into the resin 2804 can be further facilitated by flood exposing, for example, a UV-cure type resin with UV light through the imprint stamp 2802 into the substrate 2804. The UV exposure 2902 cross-links the resin 2804 and helps to solidify the resin 2804.
  • UV radiation 2902 for example, a UV-cure type resin with UV light through the imprint stamp 2802 into the substrate 2804.
  • the UV exposure 2902 cross-links the resin 2804 and helps to solidify the resin 2804.
  • FIG. 29 provides an illustration of a UV-curable resin
  • the present invention is not limited to this approach.
  • the principle of deforming the imprint stamp 2802 and/or the substrate 2804 with a bow is also applicable using a thermal resin.
  • thermal resin With thermal resin, the substrate and imprint mask are brought together at an elevated temperature which is sufficient to soften the resin.
  • the pattern from the imprint stamp 2802 can be physically pressed into the softened resin 2804 by applying pressure 2904 and the pattern printed.
  • a thermal resin no U-V exposure is required to cure the resin.
  • Both the stamp 2802 and the substrate platen 2812 are typically heated and temperature controlled in the case of thermal imprinting.
  • FIG. 30 is an illustration of the imprint stamp 2802 being separated from the substrate 2804 in accordance with the present invention.
  • the release of the vacuum and reduction of the pressure 2904 between the stamp 2802 and the substrate 2804 initiates the separation process.
  • the imprint stamp 2802 and the substrate 2804 begin to separate, or peel apart, at the outer edges 3002 and 3004 first.
  • the separation progresses to the center portion 2810 of the substrate 2804 in a carefully controlled manner as the pressure is fully released.
  • the substrate 2804 can be unloaded from the apparatus 2800.
  • the substrate 2804 can be a disk, or a disk having a hole through its center.
  • FIG. 31 is a flowchart of an exemplary method 3100 of practicing an embodiment of the present invention.
  • at least one of a surface of an imprint stamp and a substrate is deformed to provide a deformed surface having an arc therein, as indicated in step 3102.
  • a clamping pressure is applied to bring the deformed surface into intimate contact with the other surface, the applied pressure substantially flattening the deformed surface.
  • the applied clamping pressure is released, as indicated in step 3106.
  • FIG. 32 is an illustration of one exemplary technique for making a nano-plate for imprint lithography in accordance with an embodiment of the present invention.
  • a nano-plate boule 3200 is built up, or developed, from hundreds of deposited thin film layers 3202 using a layering approach to form, for example, a ring layer structure 3203.
  • the nano-plate boule 3200 is constructed by depositing thin films of two or more materials 3204 and 3206 produced from two or more thin film deposition sources 3208 and 3210, respectively.
  • the deposition of the materials 3204 and 3206 is aided by respective shutter assemblies 3212 and 3214.
  • the materials 3204 and 3206 are deposited in an alternating manner onto the boule 3200 as it rotates in a direction 3216 around a central core 3218.
  • FIG. 32 illustrates the boule 3200 rotating in a counter-clockwise direction for purposes of illustration only.
  • the present invention is in no way limited to counter-clockwise rotation.
  • the central core 3218 can be, for example, a solid rod, a hollow cylinder, or other similar structure.
  • An exemplary diameter of the central core 3218 might be greater than about 2 millimeters (mm).
  • the thin film materials 3204 and 3206 can be deposited as the nano-plate boule 3200 rotates, as shown.
  • the deposition sources 3208 and 3210 can be rotated around the central core 3218, to create the circularly symmetrical ring layer structure 3203.
  • the deposited film layers 3202 form separate and concentric rings within the layer structure 3203.
  • one of the sources e.g. the source 3208 will switched off while a film comprised of a first of the thin film materials (e.g., material 3206) is being deposited by the other source 3210.
  • a film comprised of a first of the thin film materials e.g., material 3206
  • its source (3210) will be switched off and the second source (3208) will be activated to deposit the film comprised of the second material (3204). This process continues until the desired thickness of the nano-plate boule 3200 is achieved.
  • the deposition process noted above ultimately produces alternating layers of the materials 3204 and 3206, as illustrated in FIG. 33.
  • the materials 3204 and 3206 can be comprised of, by way of example, silicon dioxide, silicon nitride, and/or silicon.
  • the materials 3204 and 3206 can alternatively be comprised of heavy metallic materials, such as tungsten, molybdenum, and tantalum, to name a few.
  • high rate magnetron biased sputtering can be used as the boule 3200 rotates. As noted above, however, it can be arranged whereby the sputter sources can be made to rotate around a stationary boule 3200. Once the boule 3200 has been built up, typically to about 85 to 90 mm in diameter, individual nano-plates can be made by slicing disks off the nano-plate boule 3200, using known slicing tools.
  • FIG. 34 is an illustration of an alternative approach to the circularly symmetrical ring layer structure 3203 of FIG. 32.
  • a nano-plate boule 3400 can be developed to have rings 3402 that form a spiral structure 3404, using a baffled deposition process.
  • each deposition source can be set such that one revolution of the boule produces the required thickness of material. If a single revolution produces the desired thickness of material, then both of the sources, for example, the sources 3208 and 3210 of FIG. 32, can be on at the same time. That is, each of the sources 3208 and 3210 would be sequentially depositing one layer on top of the other, around the boule 3400 continuously, to form the spiral structure 3404.
  • the thin film deposition process can be accomplished using a variety of methods well known to those of skill in the art. For example, sputter deposition, chemical vapors deposition, plasma vapor deposition or similar thin film deposition systems can be used. Deposition of the materials can be accomplished using two or more deposition sources.
  • the deposited thin films can be made from many material combinations. Within the context of the present invention, it is preferable that one or more of the materials, such as the materials 3204 and 3206, be selectively etched. Additionally, the materials can be deposited in extremely smooth films, where there is no significant inter-diffusion of the layer during processing that will degrade the definition of the layer thickness.
  • An example of readily available material combinations that can be used to form the discrete layers, and hence the rings are SiO 2 ZSi 3 N 4 , SiO 2 /Si, SiO 2 /Ta, and SiO 2 /magnetic media. There also are other exemplary suitable combinations not mentioned in the present application, but will become apparent to persons having ordinary skill in the art based on this description.
  • the deposition process be controlled to provide sufficiently smooth layers such that as the layers build up, there is no deviation from a smooth circular track.
  • bias magnetron sputter deposition can be used to maintain a very smooth deposited film surface while at the same time, achieving a high deposition rate.
  • nano imprint masks can be made by cutting slices out of the boule 3200 and polishing the cut surface that will have ring structures resembling, for example, the ring sections of a tree trunk.
  • Each tree ring section cut from the boule 3200 undergoes a polishing, or planarizing, process to provide a very flat surface.
  • a selective etch is used to cut layers comprised of a first of the materials (e.g., 3206) selectively against layers comprised of a second of the materials (e.g., 3204).
  • the layers are cut to a depth required for an imprint mask, typically about 40 nanometers (nm), for 30 nm lines and spaces.
  • FIG. 35 is a cross-sectional view of one nano-plate 3500 sliced from the circularly symmetrical ring layer structure 3203 of the boule 3200.
  • tracks such as the tracks 3502 are formed in a polished nano-plate surface 3504 by selectively etching the film layers comprising material 3204 against the film layers comprising material 3206, as noted above.
  • the tracks 3502 are etched to form trenches, such as the trenches 3506, in the nano-plate surface 3504.
  • a width 3508 of the tracks 3502 can be within a range of about 1 to 100 nm.
  • a preferable width value is on the order of about 30 nm.
  • the width 3508 of the tracks correspond to line and space widths in the context of lithography terminology.
  • the trenches 3506 are formed to a depth 3510 of about 45 nm to form the 30 nm lines and spaces, noted above.
  • the etching of the tracks 3502 to form the trenches 3506 can be accomplished using well known semiconductor etching techniques. For example, a plasma type etcher could be used to reactively etch, or vaporize, the film layers of the material 3206 to form the trenches 3506.
  • FIG. 36 is an illustration of an alternative nano-plate structure 3600.
  • the alternative nano-plate structure 3600 is rectangular in shape as opposed to the circular ring layer structure 3203 illustrated in FIG. 32.
  • the rectangular structure 3600 includes rectangular film layers 3602 formed around a central core 3604.
  • the sections of the boule can be cut up in various ways to form stamps with linear or curved tracks.
  • planarization can be achieved by using standard chemical mechanical polishing (CMP) processes.
  • CMP chemical mechanical polishing
  • the planarization or smoothing can also be accomplished by sputter etching, for example, a planarizing resist coating.
  • a nano-plate can be formed having a central hole or bore therethrough, by building the nano-plate boule 3200 around a hollow tube, rather than a solid rod (coolant for deposition processing can be passed through the hollow portion of the tube to control the deposition processing temperature).
  • quartz is used for the center of the boule although other materials can be used.
  • the final line width and spacing is controlled by the thin layer thickness for the deposited films. Layer thickness is controlled by deposition rate and rotation rates of the boule relative to the sources.
  • the widths of the rings can be varied in a controlled manner.
  • the formatting structures can be added to the nano-plate 3500 to enable the nano-plate 3500 to be used as a storage medium. This is achieved by using a lithographic printing process on the platen surface 3504, before etching out the tracks 3502 to form the trenches 3506.
  • the techniques of the present invention are also capable of defining the highest possible track resolutions. Track widths of 10 nm can be defined very uniformly, which is beyond the capabilities of standard optical e-beam lithography. By changing track thicknesses, lithographically printing formatting structures can be defined on the disk 3500. This method enables greater than 200 Terabyte hard drive capability.
  • FIG. 37 is a flowchart of an exemplary method 3700 of practicing an embodiment of the present invention.
  • two or more types of film are deposited around a central core to form a plurality of film layers, as illustrated in step 3702.
  • Each film layer being of a different type than its adjacent layers.
  • the deposited film layers are sectioned to expose a patterned surface.
  • the patterned surface is then planarized as indicated in step 3706 and patterns comprised of one of the types of film are selectively etched to a predetermined depth to produce a selectively etched surface, as indicated in step 3708.
  • FIG. 38 is an illustration of one exemplary technique of making a computer hard drive platen in accordance with an embodiment of the present invention.
  • a boule 3800 is built up, or developed, from possibly millions of deposited thin film layers 3802 using a layering approach to form, for example, a ring layer structure 3803.
  • the boule 3800 is made by depositing thin films of two or more materials, such as materials 3804 and 3806, in an alternating manner onto the boule 3800 as it rotates in a direction 3808 around a central core 3810.
  • FIG. 38 illustrates the boule 3800 rotating in a counter-clockwise direction for purposes of illustration only. The present invention is in no way limited to a counter-clockwise rotation.
  • the central core 3810 can be, for example, a solid rod, a hollow cylinder, or other similar structure.
  • An exemplary diameter of the central core 3810 might be greater than about 2 millimeters (mm).
  • the materials 3804 and 3806 are sequentially deposited using exemplary thin film deposition sources 3812 and 3814, respectively.
  • the boule 3800 can be rotated as shown.
  • the deposition sources 3812 and 3814 can be rotated around the central core 3810, to create the circularly symmetrical ring layer structure 3803.
  • the deposited film layers 3802 form separate and concentric rings within the layer structure 3803.
  • one of the sources 3812 or 3814 will switched off while a film comprised of a first of the materials 3804 or 3806 is being deposited by the other source.
  • its source e.g., 3812
  • the second source 3814
  • the deposition process noted above ultimately produces alternating layers of the materials 3804 and 3806, as illustrated in FIG. 39.
  • the materials 3804 and 3806 can comprise, by way of example, silicon dioxide, silicon nitride, and/or silicon.
  • the materials 3804 and 3806 can also comprise heavy metallic materials, such as tungsten, tantalum, and molybdenum, to name a few.
  • high rate magnetron biased sputtering was used as the boule 3800 rotated. As noted above, however, it can be arranged whereby the sputter sources can be made to rotate around a stationary boule 3800. Once the boule has been built up, typically to about 85 to 90 mm in diameter, platens can be made by slicing disks off the boule 3800, using known slicing tools.
  • FIG. 40 is an illustration of an alternative approach 4000 to the circularly symmetrical ring layer structure 3803 of FIG. 38.
  • a boule 4000 can be developed to have rings 4002 that form a spiral structure 4004, using a baffled deposition process.
  • each deposition source can be set such that one revolution of the boule produces the required thickness of material. If a single revolution produces the desired thickness of material, then both of the sources, for example, the sources 3812 and 3814 of FIG. 38, can be on at the same time. That is, each of the sources 3812 and 3814 would be sequentially depositing a layer, one layer on top of the other, around the boule 4000 continuously, to form the spiral structure 4000.
  • the thin film deposition process can be accomplished using a variety of methods well known to those of skill in the art. For example, sputter deposition, chemical vapors deposition, Plasma Vapor Deposition or similar thin film deposition systems can be used. Deposition of the materials can be accomplished using two or more deposition sources.
  • the deposited thin films can be made from many material combinations. Within the context of the present invention, it is preferable that one or more of the material, such as the materials 3804 and 3806, be selectively etched. Additionally, the materials can be deposited in extremely smooth films, where there is no significant inter-diffusion of the layer during processing that will degrade the definition of the layer thickness.
  • An example of readily available material combinations that can be used to form the discrete layers, and hence the rings are SiO 2 /Si 3 N 4 , SiOa/Si, SiO 2 /Ta, and SiO 2 Magnetic Media Film. There also are other exemplary combinations not mentioned in the present application, but will become apparent to persons having ordinary skill in the art based on this description.
  • the deposition process be controlled to provide sufficiently smooth layers such that as the layers build up, there is no deviation from a smooth circular track.
  • bias magnetron sputter deposition can be used to maintain a very smooth deposited film surface while at the same time, achieving a high deposition rate.
  • FIG. 41 is a cross-sectional portion (disk) 4100 of the circularly symmetrical ring layer structure 3803 of the boule 3800.
  • tracks such as the tracks 4102, are formed in a polished platen surface 4104 of the disk 4100 by selectively etching the film layer comprising material 3804 against the film layer comprising material 3806.
  • the tracks 4102 are etched to form trenches, such as the trenches 4106, in the platen surface 4104.
  • a width 4108 of the tracks 4102 can be within a range of about 1 to 100 nanometers (nm).
  • a preferable width value is on the order of about 30 ran.
  • the width 4108 of the tracks correspond to line and space widths in the context of lithography terminology.
  • the trenches 4106 are formed to a depth 4110 of about 45 nm to form the 30 nm lines and spaces, noted above.
  • the etching of the tracks 4102 to form the trenches 4106 can be accomplished using well known semiconductor etching techniques. For example, a plasma type etcher could be used to reactively etch, or vaporize, the film layers of the material 3806 to form the trenches 4106. Wet selective etching can also be used.
  • FIG. 42 is an illustration of the cross-sectional portion 4100 of FIG. 41 having a magnetic media deposited in the trenches 4106 sections, in accordance with the present invention.
  • the trenches 4106 in the disk platen surface 4104 are filled by coating the disk with magnetic media.
  • the platen surface 4104 is then planarized again to leave discrete isolated tracks of magnetic media 4200 in the areas of the trenches 4106 that were etched from the tracks 4102.
  • Planarization can be achieved by using standard chemical mechanical polishing (CMP) processes.
  • CMP chemical mechanical polishing
  • the planarization or smoothing can also be accomplished by sputter etching a planarizing resist coating with 1 : 1 selectively against the magnetic media 4200 coat.
  • platens can be formed having a central hole or bore, by building the boule up on a hollow tube, rather than a solid rod (coolant for the deposition process can be passed through the hollow tube to control the deposition processing temperature).
  • a solid rod coolant for the deposition process can be passed through the hollow tube to control the deposition processing temperature.
  • quartz is used for the center of the boule although other materials can be used.
  • the final data track width and spacing is controlled by the thin layer thickness for the deposited films. Layer thickness is controlled by deposition rate and rotation rates of the boule relative to the sources.
  • the widths of the rings can be varied in a controlled manner. Formatting structures can be added to the disk 4100 by using a lithographic printing process on the platen surface 4104, before etching or after etching out the tracks 4102 to form the trenches 4106.
  • the nano-plate can be mounted on a central boss structure to ensure correct balance for high speed disk rotation. Both the upper and the lower surface of the disk can have data tracks formed on them. These upper and lower tracks will be perfectly aligned to each other
  • the technique of the present invention is capable at defining the highest possible track resolutions.
  • Track widths of lOnm can be defined very uniformly which is beyond the capabilities of optical e-beam lithography.
  • By changing track thicknesses or lithographically printing format structure can be defined on the disk. This method enables greater than 200 Terabyte hard drive capability.
  • FIG. 43 is a flowchart of an exemplary method 4300 of practicing an embodiment of the present invention.
  • two or more types of film are deposited around a central core to form a plurality of film layers, as illustrated in step 4302. Each film layer being of a different type than its adjacent layers.
  • the deposited film layers are sectioned to expose a patterned surface. The patterned surface is then polished as indicated in step 4306.
  • the exposed patterns are selectively etched to expose patterns comprised of one of the types of film to a predetermined depth to produce a selectively etched surface.
  • magnetic material is deposited within etches of the surface, as indicated in step 4310.
  • the surface is planarized to form separated magnetic tracks therein.

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Abstract

Provided are methods and systems for forming nanodisks used in imprint lithography and memory disks formed by the nanodisks.

Description

SYSTEMS AND METHODS FOR FORMING NANODISKS USED IN IMPRINT LITHOGRAPHYAND NANODISK AND MEMORY DISK
FORMED THEREBY
FIELD
[0001] The present invention relates to imprint lithography.
BACKGROUND
[0002] A lithographic apparatus is a machine that applies a desired pattern onto a target portion of a substrate. Lithographic apparatus are conventionally used, for example, in the manufacture of integrated circuits (ICs), flat panel displays and other devices involving fine structures.
[0003] It is desirable to reduce the size of features in a lithographic pattern because this allows for a greater density of features on a given substrate area. In photolithography, the increased resolution can be achieved by using light of shorter wavelength. However, there are problems associated with such reductions. Current systems are starting to adopt optical sources with wavelengths in the 193 nm regime, but even at this level, diffraction limitations become a barrier. At lower wavelengths, the transparency of materials is very poor. Optical lithography machines capable of enhanced resolutions require complex optics and rare materials and are consequently very expensive.
[0004] An alternative for printing sub-lOOnm features, known as imprint lithography, comprises transferring a pattern to a substrate by imprinting a pattern into an imprintable medium using a physical mold or template. The imprintable medium can be the substrate or a material coated on to a surface of the substrate. The imprintable medium can be functional or can be used as a "mask" to transfer a pattern to an underlying surface. The imprintable medium can, for example, be provided as a resist deposited on a substrate, such as a semiconductor material, to which the pattern defined by the template is to be transferred. Imprint lithography is thus essentially a molding process on a micrometer or nanometer scale in which the topography of a template defines the patterns created on a substrate. Patterns can be layered as with optical lithography processes so that in principle imprint lithography could be used for such applications as IC manufacture.
[0005] The resolution of imprint lithography is limited only by the resolution of the template fabrication process. For example, imprint lithography has been used to produce features in the sub-50 nm range with significantly improved resolution and line edge roughness compared to that achievable with conventional optical lithography processes. In addition, imprint processes do not require expensive optics, advanced illumination sources, or specialized resist materials typically required by optical lithography processes.
[0006] Current imprint lithography processes can have a number of drawbacks particularly with regard to achieving overlay accuracy and high throughput. However, significant improvements in resolution and line edge roughness attainable are from imprint lithography.
[0007] Imprint lithography is being used to form memory disks or memory platens that adhere to an ever increasing requirement for very dense data bit formation. However, forming denser data bits means each bit must be smaller and closer together. This closeness of the data bits can lead to data bits becoming unstable, either through thermal influences or outside magnetic influences (e.g., through superpara magnetism).
[0008] Therefore, what is needed is a system and method that can form dense and relatively small isolated data bits that will remain stable even when influenced by extraneous magnetic and thermal influences, for example through forming them as discrete isolated islands of magnetic material.
[0009] With the traditional used UV curable and thermally deformable resins, separating the stamp from the resin, after imprinting, can be particularly problematic. That is, it is difficult to separate the resin and the stamp in a way that is not impeded by the stamp sticking to the resin, particularly when a vacuum has been used to aid the impress process. Additionally, newer applications for Imprint Stamping require patterning on two sides of the substrate, further complicating the problems noted above.
[0010] What is needed, therefore, is a system and method to alleviate the challenge of separating a stamp from the resin after an imprint stamp is used to imprint a pattern into the resin. What is also needed is a system and method to enhance the speed of imprint stamping on two sides of the substrate. [001 Ij A conventional imprint mask used in nano-imprint technology is generally a quartz or hard surface plate that has been patterned and manufactured using an electron-beam (E-beam) lithography or ion beam lithography pattern writing system. After the required pattern has been written and an image developed in a layer of a resist, the pattern is transferred into the quartz or hard surface using an etch process. A shallow topography is formed in the quartz or hard surface that can be impressed into a plastic medium to give a pattern transfer.
[0012] Using the conventional imprint mask manufacturing process, there is a resolution cost issue associated with writing 1 x structures less than 30 nanometers (nm) wide. That is, it takes a very long time per square inch to manufacture the mask. Even worse, the manufactured mask may have a severely restricted useful life and it is very difficult to define the 1 x imprint masks, even using E-beam technology. This is especially true for patterns having circular symmetry that can be used for imprinting, for example, data tracks onto a data storage disk.
[0013] What is needed, therefore, is a method and system for developing a nano-plate for imprint lithography that overcomes the manufacturing challenges associated with traditional imprint masks.
[0014] Platens used in hard drives for data storage on computers comprise flat disks coated with a thin film of magnetic storage media. A read/write head flies close to a surface of the platen, as it rotates, to transfer data from or to magnetic domains in a media film. Data is written into tracks which form concentric magnetic rings in the media.
[0015] Requirements for higher data storage density requires that the magnetized tracks are closer together and made narrower. As magnetic domains are pushed closer together, however, they reach a resolution limit for the separation of stored data bits. It also becomes difficult for the read/write heads to follow the magnetically defines tracks.
[0016] What is needed, therefore, is a method and system for developing magnetic storage media capable of accommodating higher data storage density requirements. SUMMARY
[0017] An embodiment of the present invention provides a method of forming a nanodisk, comprising the following steps. Forming a first annular pattern comprising alternating sections of first and second materials. Imprinting the first annular pattern with a second pattern to form a cross hatched pattern on the first pattern. Selectively etching portions of the first and the second patterns on the nanodisk.
[0018] Another embodiment of the present invention provides a method of forming a wedge-shaped pattern comprising the following steps. Producing first and second materials using first and second thin film deposition sources. Alternating passage of the first and second materials through respective first and second shutters. Transmitting the fist and second materials using respective first and second openings of a deposition baffle. Rotating a substrate on an opposite side of the deposition baffle as the first and second deposition sources, the rotating substrate receiving the first and second materials to form successive layers of a boule. Removing sections of the boule to form the wedge-shaped pattern.
[0019] A further embodiment of the present invention provides a nanodisk for use in imprint lithography comprising tracks on a substrate and selectively etched areas proximate the tracks. The selectively etched areas form data bit areas when the nanodisk is imprinted onto a memory platen.
[0020] A still further embodiment of the present invention provides a memory platen comprising main tracks, isolated data bits, and servo tracks. The main tracks are formed by main tracks of a nanodisk. The isolated data bits are formed by data bit areas on the nanodisk, the data bit areas of the nanodisk being located proximate the main tracks of the nanodisk. The servo tracks are formed by servo tracks of the nanodisk, the servo tracks of the nanodisk being locating proximate one or more of the main tracks of the nanodisk.
[0021] A yet further embodiment of the present invention provides a method of manufacturing a memory disk. Main tracks are formed on a disk platen. Isolated bit areas are formed with respect to the main tracks on the disk platen. A magnetic layer is formed on the isolated bit areas with magnetic material to form discrete isolated data bits. [0022] In another embodiment, consistent with the principles of the present invention, as embodied and broadly described herein, the present invention includes a method for imprinting patterns formed on opposing surfaces of first and second imprint stamps onto first and second sides of a substrate, respectively. The method includes deforming the surfaces of the first and second imprint stamps to produce respective first and second deformed surfaces, each having an arc therein. A pressure is applied to bring the deformed first and second surfaces into intimate contact with the first and second substrate surfaces, respectively. The applied pressure substantially flattens the deformed surfaces. And to separate the two surfaces from the respective surfaces of the substrate, the applied pressure is released.
[0023] The imprint apparatus of the present invention may print on both sides of a substrate, simultaneously. The apparatus can employ, for example, two stamps, which are aligned to provide registration between top and bottom patterns. The substrate is introduced between the two stamps and is aligned to them. The apparatus has subsystems which provide positioning and alignment of Stamp A, Stamp B, and the substrate. Substrate handling is provided. Temperature and pressure monitoring system are provided. X, Y, Z and tilt adjustments are provided for stamps and substrate. The imprint apparatus may also be used to print one side of a substrate first and then print a second side of the substrate.
[0024] The stamps have induced bows in their surface to facilitate peel-off and stamp release from the substrate. In one embodiment of the present invention, the imprint apparatus is used for producing patterned media for magnetic data storage. Tracks and Magnetic Domain patterns are aligned and printed on both sides of the data storage platens. One or more embodiments of the present invention are applicable to any imprint lithography process in which a patterned template is imprinted into an imprintable medium in a flowable state, and, for example, can be applied to hot and UV imprint lithography as described above.
[0025] In another embodiment of the present invention, a system is provided that comprises a substrate, a carrier, and first and second imprint stamps. The substrate has first and second patterning surfaces and a shaped edge. The carrier has a holding portion that holds the shaped edge of the substrate. The holding surface has a shape that is complementary to the shaped edge of the substrate, such that the patterning surfaces remain untouched by the carrier. The first and second imprint stamps form patterns on respective ones of the first and second patterning surfaces.
[0026] In a still further embodiment of the present invention, consistent with the principles of the present invention, as embodied and broadly described herein, the present invention includes a method for imprinting a pattern formed on a surface of an imprint mask into a substrate. The method includes deforming at least one of the surface of the imprint mask and a surface of the substrate to produce a deformed surface having an arc therein. A clamping pressure is applied to bring the deformed surface into intimate contact with the other surface, the applied pressure substantially flattening the deformed surface. To separate the two surfaces, the applied clamping pressure is released.
[0027] In yet another embodiment of the present invention, consistent with the principles of the present invention, as embodied and broadly described herein, the present invention includes a method for manufacturing a nano-plate, for example. The method includes depositing two or more types of film around a central core to form a plurality of film layers, each film layer being of a different type than its adjacent layers. Next, the deposited film layers are sectioned to expose a patterned surface. Finally, the patterned surface is then planarized and selectively etched to expose patterns comprised of one of the types of film to a predetermined depth to produce a selectively etched surface. This plate is then used as a stamp to impress an image of the circular tracks into a resin material. The track pattern is transferred from the resin into the underlying disk material to form a hard drive platen.
[0028] In another embodiment of the present invention, consistent with the principles of the present invention, as embodied and broadly described herein, the present invention includes a method for manufacturing a hard drive platen, for example. The method includes depositing two or more types of film around a central core to form a plurality of film layers, each film layer being of a different type than its adjacent layers. Next, the deposited film layers are sectioned to expose a patterned surface. The patterned surface is then polished and selectively etched to expose patterns comprised of one of the types of film to a predetermined depth to produce a selectively etched surface. Magnetic material is deposited to fill resulting etched trenches. The surface is then planarized to form a smooth surface with inlaid tracks of magnetic material. The surface having the tracks of magnetic material is then planarized.
[0029] According to a still yet further embodiment, the present invention provides several solutions to enabling magnetic media to accommodate higher data storage density requirements. More specifically, the prevent invention provides a technique for creating a platen disk with physically separated tracks of magnetic media at line widths and pitch beyond the capabilities of either optical or electron beam lithography.
[0030] One exemplary approach for implementing the technique of the present invention is to physically separate the magnetic media into tracks that isolate the magnetic domains and form a physical structure for the read/write heads to follow.
[0031] Further embodiments, features, and advantages of the present inventions, as well as the structure and operation of the various embodiments of the present invention, are described in detail below with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES
[0032] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate one or more embodiments of the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention.
[0033] Figures 1, 2, and 3 illustrate examples of conventional soft, hot and UV lithography processes, respectively.
[0034] Figure 4 illustrates a two-step etching process employed when hot and
UV imprint lithography is used to pattern a resist layer.
[0035] Figure 5 schematically illustrates a template and a typical imprintable resist layer deposited on a substrate.
[0036] Figure 6 shows a view of a first pattern on a substrate, according to one embodiment of the present invention.
[0037] Figure 7 shows a view of a second pattern on a substrate, according to one embodiment of the present invention. [0038] Figures 8 and 9 show top and perspective views, respectively, of overlapped first and second patterns in Figures 6 and 7, respectively, according to one embodiment of the present invention, for example when imprint is used for pattern transfer. [0039] Figures 10 and 11 show views of the imprint stamp during and after an etching process, respectively, according to one embodiment of the present invention. [0040] Figure 12 shows an imprint stamp after an etching process and removal of resist, according to one embodiment of the present invention. [0041] Figure 13A is a cross-sectional view of a system used to form the second pattern shown in Figure 7, according to one embodiment of the present invention. [0042] Figure 13B shows a portion of the system in Figure 13 A, according to another embodiment of the present invention. [0043] Figure 14 is a view of a deposition baffle, according to one embodiment of the present invention. [0044] Figure 15 shows a core for producing an imprint stamp having servo tracking patterns, according to one embodiment of the present invention. [0045] Figure 16 is a view of patterns on an imprint stamp to produce servo tracking patterns, according to one embodiment of the present invention. [0046] Figure 17 includes waveforms generated by a head reading servo tracking patterns, according to one embodiment of the present invention. [0047] Figures 18 and 19 show flowcharts depicting various methods of practicing various embodiments of the present invention. [0048] Figures 20, 21, 22, and 23 show various complementary shapes for substrate edge and carrier holding portions, according to various embodiments of the present invention. [0049] Figure 24 is an illustration of an exemplary apparatus including two imprint stamps and a double-sided substrate arranged in accordance with an embodiment of the present invention. [0050] Figure 25 is an illustration of the stamps and substrate illustrated in
Figure 24 being exposed to optional ultra-violet (UV) radiation (UV exposure not required for thermal imprints) and applied pressure. [0051] Figure 26 is an illustration of the stamps being separated from the resin in accordance with the present invention. [0052] Figure 27 is a flowchart of an exemplary method of practicing an embodiment of the present invention. [0053] FIG.28 is an illustration of an exemplary apparatus including an imprint stamp and substrate arranged in accordance with an embodiment of the present invention; [0054] FIG. 29 is an illustration of the stamp and substrate illustrated in FIG.28 being exposed to ultra-violet (UV) radiation (UV exposure not required for thermal imprints); [0055] FIG. 30 is an illustration of the stamp being separated from the resin in accordance with the present invention; and [0056] FIG. 31 is a flowchart of an exemplary method of practicing an embodiment of the present invention. [0057] FIG. 32 is an illustration of an apparatus for making an imprint stamp in accordance with an embodiment of the present invention. [0058] FIG. 33 is a more detailed illustration of a ring structure used within the apparatus illustrated in FIG. 32. [0059] FIG. 34 is an illustration of an alternative to the ring structure of the apparatus shown in FIG. 32. [0060] FIG. 35 is a cross-sectional portion of the ring structure illustrated in
FIG. 32 in accordance with an embodiment of the present invention [0061] FIG. 36 is an illustration of another alternative to the ring structure of the apparatus shown in FIG. 32. [0062] FIG. 37 is a flowchart of an exemplary method of practicing an embodiment of the present invention. [0063] FIG. 38 is an illustration of an apparatus for making a computer hard drive platen in accordance with an embodiment of the present invention. [0064] FIG. 39 is a more detailed illustration of a ring structure used within the apparatus illustrated in FIG. 38. [0065] FIG. 40 is an illustration of an alternative to the ring structure of the apparatus shown in FIG. 38. [0066] FIG. 41 is a cross-sectional portion of the ring structure illustrated in
FIG. 38 in accordance with an embodiment of the present invention. [0067] FIG. 42 is an illustration of the cross-sectional portion of FIG. 41 having a magnetic media deposited in grooved sections in accordance with the present invention and after being planarized.
[0068] FIG. 43 is a flowchart of an exemplary method of practicing an embodiment of the present invention.
DETAILED DESCRIPTION
[0069] The following detailed description of the present invention refers to the accompanying drawings that illustrate exemplary embodiments consistent with this invention. Other embodiments are possible, and modifications may be made to the embodiments within the spirit and scope of the invention. Therefore, the following detailed description is not meant to limit the invention. Rather, the scope of the invention is defined by the appended claims.
[0070] It would be apparent to one skilled in the art that the present invention, as described below, may be implemented in many different embodiments of hardware and/or the entities illustrated in the drawings. Thus, the operation and behavior of the present invention will be described with the understanding that modifications and variations of the embodiments are possible, given the level of detail presented herein.
[0071 ] One or more embodiments of the present invention provide a system and method to form a memory disk having isolated data bits, for example using imprint lithography. In the example using imprint lithography, the imprint stamp is formed from first and second overlapping patterns, where the patterns are selectively etched. The selective etching leaves either pits or posts on the imprint stamp. The pits or posts are imprinted on the memory disk, leaving either pits or posts on the memory disk. The pits or posts on the memory disk are processed to form relatively small and dense isolated data bits. Instability of the isolated data bits caused by outside magnetic and thermal influences is substantially eliminated.
[0072] There are two principal approaches to imprint lithography, which will be termed generally as hot imprint lithography and UV imprint lithography. There is also a third type of "printing" lithography known as soft lithography. Examples of these are illustrated in Figures 1 to 3. [0073] Figure 1 shows the soft lithography process that involves transferring a layer of molecules 11 (typically an ink such as a thiol) from a flexible template 10 (typically fabricated from polydimethylsiloxane (PDMS)) onto a resist layer 13 that is supported upon a substrate 12 and planarization and transfer layer 12\ The template 10 has a pattern of features on its surface, the molecular layer being disposed upon the features. When the template is pressed against the resist layer the layer, of molecules 11 stick to the resist. Upon removal of the template from the resist, the layer of molecules 11 stick to the resist and the residual layer of resist is etched, such that the areas of the resist not covered by the transferred molecular layer are etched down to the substrate.
[0074] The template used in soft lithography can be easily deformed and can therefore not be suited to high-resolution applications, e.g., on a nanometer scale, since the deformation of the template can adversely affect the imprinted pattern. Furthermore, when fabricating multiple layer structures, in which the same region will be overlaid multiple times, soft imprint lithography may not provide overlay accuracy on a nanometer scale.
[0075] Hot imprint lithography (or hot embossing) is also known as nanoimprint lithography (NIL) when used on a nanometer scale. The process uses harder templates made from, for example, silicon or nickel, which are more resistant to wear and deformation. This is described, for example, in U.S. Patent No. 6,482,742 and illustrated in Figure 2 of the instant application.
[0076] In a typical hot imprint process a solid template 14 is imprinted into a thermosetting or a thermoplastic polymer resin 15, which has been cast on the surface of a substrate 12. The resin can, for example, be spin coated and baked onto the substrate surface or more typically (as in the example illustrated) onto a planarization and transfer layer 12'. It shall be understood that the term "hard" when describing an imprint template includes materials that can generally be considered between "hard" and "soft" materials, such as for example "hard" rubber. The suitability of a particular material for use as an imprint template is determined by its application requirements.
[0077] When a thermosetting polymer resin is used the resin is heated to a temperature such that, upon contact with the template, the resin is sufficiently flowable to flow into the pattern features defined on the template. The temperature of the resin is then increased to thermally cure (e.g., crosslink) the resin so that it solidifies and irreversibly adopts the desired pattern. The template can then be removed and the patterned resin cooled.
[0078] Examples of thermoplastic polymer resins used in hot imprint lithography processes are poly (methyl methacrylate), polystyrene, poly (benzyl methacrylate) or poly (cyclohexyl methacrylate). The thermoplastic resin is heated so that it is in a freely flowable state immediately prior to imprinting with the template. It is typically necessary to heat thermoplastic resins to temperatures considerably above the glass transition temperature of the resin. The template is pressed into the flowable resin and sufficient pressure is applied to ensure the resin flows into all the pattern features defined on the template. The resin is then cooled to below its glass transition temperature with the template in place whereupon the resin irreversibly adopts the desired pattern. The pattern will consist of the features in relief from a residual layer of the resin that can then be removed by an appropriate etch process to leave only the pattern features.
[0079] Upon removal of the template from the solidified resin, a two-step etching process is performed as illustrated in Figure 4. The substrate 20 has a planarization and transfer layer 21 upon it, as shown in step a. The purpose of the planarization and transfer layer is twofold. It acts to provide a surface parallel to that of the template, which is important to ensure that the contact between the template and the resin is parallel, and also to improve the aspect ratio of the printed features, as will be described below.
[0080] After the template has been removed, a residual layer 22 of the solidified resin is left on the planarization and transfer layer, shaped in the desired pattern. The first etch is anisotropic and removes parts of the residual layer, resulting in a high aspect ratio of features where Ll is the height of the features 23, as shown in step b. The second etch is anisotropic (or selective) and further improves the aspect ratio. The anisotropic etch removes those parts of the planarization and transfer layer which are not covered by the solidified resin, increasing the aspect ratio of the features 23 to (L2/D), as shown in step c. The resulting polymer thickness contrast left on the substrate after etching can be used as, for example, a mask for dry etching if the imprinted polymer is sufficiently resistant, for example, as a step in a lift-off process. [0081] Hot imprint lithography suffers from a disadvantage in that not only is the pattern transfer to be performed at a higher temperature, but also relatively large temperature differentials might be required in order to ensure the resin is adequately solidified before the template is removed. Temperature differentials between about 35 and about 100 0C are known from literature. Differential thermal expansion between, for example, the substrate and template, can then lead to distortion in the transferred pattern. The problem is exacerbated by the relatively high pressures used for the imprinting step, due the viscous nature of the unprintable materials, which can induce mechanical deformation in the substrate, again distorting the pattern. It is to be appreciated that the imprint temperature and pressure are critical to successful imprinting.
[0082] UV imprint lithography on the other hand does not involve such high temperatures and temperature changes. Nor does it require such viscous imprintable materials. Rather UV imprint lithography involves the use of a transparent template and a UV-curable liquid, typically a monomer such as an acrylate or methacrylate for example. In general any photopolymerisable material could be used, such as a mixture of monomers and an initiator. The curable liquid can also, for example, include a dimethyl siloxane derivative. Such materials are much less viscous than the thermosetting and thermoplastic resins used in hot imprint lithography and consequently move much faster to fill template pattern features. Low temperature and low pressure operation also favors higher throughput capabilities.
[0083] An example of a UV imprint process is illustrated in Figure 3. A quartz template 16 is applied to a UV-curable resin 17 in a similar manner to the process of Figure 4. Instead of raising the temperature as in hot embossing employing thermosetting resins, or temperature cycling when using thermoplastic resins, UV light is applied to the resin through the quartz template in order to polymerize and thus cure it. Upon removal of the template, the remaining steps of etching the residual layer of resist are the same as for the hot embossing process described above. The UV curable resins typically used have a much lower viscosity than typical thermoplastic resins so that lower imprint pressures can be used. Reduced physical deformation due to the lower pressures, together with reduced deformation due to high temperatures and temperature changes, makes LJV imprint lithography better suited to applications requiring high overlay accuracy. In addition, the transparent nature of UV imprint templates can accommodate optical alignment techniques simultaneously to the imprint.
[0084] Although this type of imprint lithography mainly uses UV curable materials, and is thus genetically referred to as UV imprint lithography, other wavelengths of light can be used to cure appropriately selected materials (e.g., activate a polymerization or cross-linking reaction). In general any radiation capable of initiating such a chemical reaction can be used if an appropriate imprintable material is available. Alternative "activating light" can, for example, include visible light, infrared light, x-ray radiation, and electron beam radiation. In the general description above, and below, references to UV imprint lithography and use of UV light are not intended to exclude these and other activating light possibilities.
[0085] As an alternative to imprint systems using a planar template that is maintained substantially parallel to the substrate surface, roller imprint systems have been developed. Both hot and UV roller imprint systems have been proposed in which the template is formed on a roller, but otherwise the imprint process is very similar to imprinting using a planar template. Unless the context requires otherwise, references to an imprint template include references to roller templates.
[0086] There is a particular development of UV imprint technology known as step and flash imprint lithography (SFIL), which can be used to pattern a substrate in small steps in a similar manner to optical steppers conventionally used in IC manufacture. This involves printing small areas of the substrate at a time by imprinting a template into a UV curable resin, 'flashing' UV light through the template to cure the resin beneath the template, removing the template, stepping to an adjacent region of the substrate and repeating the operation. The small field size of such step and repeat processes minimizes pattern distortions CD variations so that SFIL is particularly suited to manufacture of IC and other devices requiring high overlay accuracy.
[0087] Although in principle the UV curable resin can be applied to the entire substrate surface, for example, by spin coating, this is problematic due to the volatile nature of UV curable resins. [0088] One approach to addressing this problem is the so-called 'drop on demand' process in which the resin is dispensed onto a target portion of the substrate in droplets immediately prior to imprinting with the template. The liquid dispensing is controlled so that a certain volume of liquid is deposited on a particular target portion of the substrate. The liquid can be dispensed in a variety of patterns and the combination of carefully controlling liquid volume and placement of the pattern can be employed to confine patterning to the target area.
[0089] Dispensing the resin on demand as mentioned is not a trivial matter.
The size and spacing of the droplets are carefully controlled to ensure there is sufficient resin to fill template features, while at the same time minimizing excess resin which can be rolled to an undesirably thick or uneven residual layer since as soon as neighboring drops touch fluid the resin will have nowhere to flow. The problems associated with overly thick or uneven residual layer are discussed below.
[0090] Figure 5 illustrates the relative dimensions of the template, imprintable material (e.g., curable monomer, thermosetting resin, thermoplastic, etc) and substrate. The ratio of the width of the substrate, D, to the thickness of the curable resin layer, t, is of the order of about 106. It will be appreciated that, in order to avoid the features projecting from the template damaging the substrate, the dimension t should be greater than the depth of the projecting features on the template.
[0091] The residual layer left after stamping is useful in protecting the underlying substrate, but as mentioned above it is also the source of a number of problems particularly when high resolution and/or overlay accuracy is desired. The first 'breakthrough' etch is anisotropic, but non-selective, and can to some extent erode the features imprinted as well as the residual layer. This is exacerbated if the residual layer is overly thick and/or uneven.
[0092] In principle, the above problem can be reduced by ensuring the residual layer is as thin as possible, but this can require application of undesirably large pressures (e.g., increasing substrate deformation) and relatively long imprinting times (e.g., reducing throughput).
[0093] The template is a significant component of the imprint lithography system. As noted above, the resolution of the features on the template surface is a limiting factor on the attainable resolution of features printed on the substrate. The templates used for hot and UV lithography are generally formed in a two-stage process. Initially, the desired pattern is written using, for example, electron beam writing, to give a high-resolution pattern in resist. The resist pattern is then transferred into a thin layer of chrome which forms the mask for the final, anisotropic etch step to transfer the pattern into the base material of the template. Other techniques, such as, for example, but not limited to, ion-beam lithography, X-ray lithography, extreme UV lithography, epitaxial growth, thin film deposition, chemical etching, plasma etching, ion etching, or ion milling could be used. Generally, a technique capable of very high resolution will be desired as the template is effectively a Ix mask with the resolution of the transferred pattern being limited by the resolution of the pattern on the template.
[0094] The release characteristics of the template can also be an important consideration. The template can, for example, be treated with a surface treatment material to form a thin release layer on the template having a low surface energy (a thin release layer can also be deposited on the substrate).
[0095] Although reference is made above to depositing UV curable liquids onto a substrate, the liquids could also be deposited on the template and in general the same techniques and considerations will apply.
[0096] Another important consideration in the development of imprint lithography is the mechanical durability of the template. The template is subjected to large forces during stamping of the resist, and in the case of hot lithography, it is also subjected to extremes of pressure and temperature. This will cause wearing of the template, and can adversely affect the shape of the pattern imprinted upon the substrate.
[0097] In hot imprint lithography there are potential advantages in using a template of the same or similar material to the substrate to be patterned in order to minimize differential thermal expansion between the two. In UV imprint lithography the template is at least partially transparent to the activation light, and accordingly quartz templates are used.
[0098] Although specific reference can be made in this text to the use of imprint lithography in the manufacture of ICs, it should be understood that imprint apparatus and methods described can have other applications, such as the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, hard disc magnetic media, flat panel displays, thin-film magnetic heads, etc.
[0099] While in the description above particular reference has been made to the use of imprint lithography to transfer a template pattern to a substrate via an imprintable resin effectively acting as a resist, in some circumstances the unprintable material can itself be a functional material, for example, having a functionality such as conductivity, optical linear or non linear response amongst others. For example, the functional material can form a conductive layer, a semiconductive layer, a dielectric layer or a layer having another desirable mechanical, electrical or optical property. Some organic substances can also be appropriate functional materials. Such applications can be within the scope of an embodiment of the present invention.
Exemplary Imprint Stamp
[0100] Figure 6 shows a view of a first pattern 600 on a substrate (not specifically shown) to begin forming a nanodisk (not shown), according to one embodiment of the present invention. The nanodisk can be an imprint stamp, a memory disk, or the like.
[0101] First pattern 600 (e.g., a first layer) formed on the substrate comprises a first material 602 (shown as light circles) and a second material 604 (shown as dark circles). Thus, first and second materials 602 and 604 are formed as alternating layers and are formed annularly around a core 606 to form a boule, for example as described in U.S. Appl. Nos. 11/012,474 and 11/012,489 discussed above, hi one example, first material 602 is silicon dioxide and second material 604 is silicon nitride. It is to be appreciated that other materials can also be used, hi some examples, first pattern 600 is referred to as a track, master track, defined track, or the like.
[0102] Figure 7 shows a view of a second pattern 710 (e.g., second layer) on a substrate, according to one embodiment of the present invention. In the example shown, second pattern 710 is formed as a radial pattern. Second pattern 710 is formed from a first material 702 (shown as dark lines) and a second material 704 (shown as light lines). Thus, first and second materials 702 and 704 are formed as alternating layers. Similar to first pattern 600, in one example first material 702 is silicon dioxide and second material 704 is silicon nitride. For example, second pattern 710 can be formed using the system shown in Figures 13A, 13B, and 14, as described in more detail below.
[0103] In accordance with a first embodiment shown in Figure 7, second pattern 710 can be formed from first and second pattern portions 710A and 710B. In accordance with a second embodiment shown in Figure 14, second pattern 710 can be formed from a single portion 710. Both of these embodiments are described in more detail below (hereinafter, both embodiments are shown and discussed as a single portion 710 for convenience, but not by limitation).
[0104] Figure 8 show a view of overlapping of the first pattern 600 of Figure 6 with second pattern 710 in Figure 7 used to form the nanodisk, according to one embodiment of the present invention. It is to be appreciated that first and second patterns 600 and 710 are not drawn to scale. As can be seen, second pattern 710 is smaller in overall size than first pattern 600, so multiple second patterns 710 are formed on first pattern 600, for example in a radial manner. For clarity, only one of second pattern 710 is fully shown overlapping first pattern 600, while the other ones of second pattern 710 are only shown in outline. When second pattern 710 overlaps first pattern 600, a Crosshatch pattern 812 is formed.
[0105] In one example, second pattern 710 is formed on first pattern 600 using known pressure, temperature, and timing methods, as would be known to skilled artisans, such that second pattern 710 is coupled to first pattern 600, or the like.
[0106] In another example, second pattern 710 is imprinted onto resist coating first pattern 600 quadrant by quadrant using second pattern 710 as a stamp. In one example, this can be done using imprint lithography techniques. In one example, alignment techniques can be used to align each imprinting of second pattern 710 onto first pattern 600 to form cross hatch pattern 812. This imprint method of forming cross-hatch pattern 812 is discussed in more detail below.
[0107] Figure 9 shows a view of the nanodisk during processing, according to one embodiment of the present invention. This view of the nanodisk is before residual resist in areas 913, which are spaces between resist areas 915, are etched away. Resist areas 915 are formed from imprinting second pattern 710 onto a resist layer formed on first pattern 600. [0108] Figures 10 and 1 1 show views of the nanodisk during and after an etching process, respectively, according to one embodiment of the present invention.
[0109] With regards to Figure 10, this view is after residual resist is etched from areas 913, leaving only resist at areas 915. Areas 1014 of first material 602 are exposed between resist areas 915, while areas 1017 of second material 604 are still covered by resist 915.
[0110] With regards to Figure 11, areas 1014 are etched to form holes or pits
1116. This is done by selectively etching at least a portion of first material (e.g., silicon dioxide) 602 of first pattern 600 through selection of an etching material or technique that etches the silicon dioxide and not the silicon nitride. In this embodiment, areas 1116 can be holes, pits, or the like in first pattern 600 of the imprint stamp. For example, the areas 1014 to be etched can be defined where the pattern formed from the first material 702 of the second pattern 710 overlaps the first material 602 of the first pattern 600. Also, areas 1017 are shown, which, as discussed and shown with respect to Figure 12, form tops of posts 1218.
[0111] In one example, when the nanodisk including areas 1116 is used in imprint lithography to imprint a pattern on a surface of a disk (not shown) or on a coating of the surface of the disk (e.g., a resin or the like), areas 1116 form posts or extending mesa structures on the surface of the memory disk that extend from the memory disk. These posts or extending mesa structures are later processed so that they comprise magnetic material that is used as a data bit (e.g., coated with a magnetic material). In one example, these posts or extending mesa structures on the memory disk are isolated "island" like structures. This allows for isolated data bit areas that are relatively small and dense to be formed on the memory disk, while allowing the data bits to remain stable, based on their isolation from each other, when influenced by outside thermal and magnetic affects.
[0112] Figure 12 shows the nanodisk after an additional etching process has been done to the nanodisk shown in Figure 11 , according to one embodiment of the present invention. This additional etching process is only performed if desired for a particular final arrangement of the nanodisk. In this example, an additional etching step subsequent to that shown in Figure 11 is performed to remove the resist 915 and at least a portion of second material 604 (e.g., silicon nitride) of first pattern 600, which was not initially selectively etched in Figure 11. This additional etching step can be used to produce a nanodisk that includes posts or mesa structures 1218, which have top surfaces 1017, which extend from the nanodisk adjacent holes or pits 1116.
[0113] In one example, when the nanodisk of Figure 12 is used in imprint lithography to produce memory disks, first pattern 600 is used to produce tracks on the memory disk and posts 1218 can be used with either a UV-cure Resin or Thermal Resist to imprint vias or holes into the memory disk proximate the tracks. These vias or holes are then partially filled with magnetic material to form isolated data bits. Based on their isolation, the data bits formed in the vias or holes will remain stable when influenced by outside thermal and magnetic effects.
Exemplary Systems for Forming an Imprint Stamp
[0114] Figure 13A is a cross-sectional view of a system 1318 that is used to form second pattern 710, according to one embodiment of the present invention. Figure 14 is a view of a deposition baffle of the system of claim 13A, according to one embodiment of the present invention.
[0115] In this embodiment, system 1318 comprises a substrate 1320 releaseably secured to a rotating carousel 1322, or any other device that can rotate substrate 1320. A first source 1324 deposits first material 702 onto substrate 1320 after first material 702 passes through a shutter 1326 and an opening 1328 in a deposition baffle 1330 (see also Figure 14 for a top view of deposition baffle 1330). Similarly, a second source 1332 deposits second material 704 onto substrate 1320 after second material 704 passes through a shutter 1334 and an opening 1336 in deposition baffle 1330. In one example, first and second source 1324 and 1332, respectively, are thin film deposition sources that operate during alternative time periods utilizing shutters 1326 and 1334.
[0116] In one example, a pie-shaped or wedge-shaped nanodisk base structure is produced to produce a pattern, such as pattern 710 shown in Figure 7. This is accomplished by depositing successive layers of first and second materials 702 and 704 onto substrate 1320 while it is being rotated by rotating carousel 1322 to produce a toroid (e.g., donut) shaped boule 1338. Boule 1338 can then be diamond sawn and have the sawn sections polished. These sawn and polished sections comprise the pie-shaped stamp base structure. The pie-shaped stamp base structure comprises a flat surface with striations of first and second materials 702 and 704 to form first and second portions 710A and 710B of second pattern 710, as shown in Figure 7.
[0117] In one example, the pie shape is produced by having reduced deposition rates of first and second materials 702 and 704 at one end of boule 1338 compared to another end of boule 1338. For example, deposition baffle 1330 can be used to control the deposition rate in conjunction with rotating carrousel 1322. This causes the deposition rate for first and second materials 702 and 704 to be highest closest to the center e.g., at positions 1340 and 1342, of the carrousel 1322 holding the boule 1338 and to be slowest at the edges, e.g., at positions 1344 and 1346, of the carousel 1322 holding the boule 1338.
[0118] Figure 13B shows a portion of the system in Figure 13 A, according to another embodiment of the present invention. In this embodiment, substrate 1320' has a sloped material receiving surface 1339. When first and second materials 702 and 704 are deposited on substrate 1320', as discussed above, a boule 1338' is formed that, when cut and polished, forms pattern 710 from a single portion, and not a double portion as discussed above with regards to Figure 13 A.
[0119] In one example, the above-described method of fabricating the nanodisk allows for almost unlimited resolution of a pattern formed on a memory disk by the nanodisk. For example, line/space resolutions of 9nm have been achieved for basic tracks formed by similarly produced nanodisks when used in imprint lithography to pattern a memory disk. In one example, discrete islands of 9nm by 9nm are thought to be possible, while other resolutions significantly below this may also be possible.
Exemplary Servo Tracking Patterns and System to Form Same
[0120] A memory disk generated with the above nanodisk formed using the systems and methods described, for example, in Figures 6-14, typically can comprise both data bit tracks, which include the data bits described above, and can also include servo tracking patterns used to guide tracking of a head or heads (e.g., read/write head(s)) over the data bit tracks. These servo tracking patterns usually consist of a set of bits offset from set of data bits associated with the track. The servo tracking pattern of the offset bits is predetermined and is shaped so that as the head (or heads) pass over the offset bits, the position of a servo head with respect to a center of a track including the data bits can be monitored.
[0121] Figure 15 shows a core 1506 having grooves 1550, according to one embodiment of the present invention. Figure 16 is a view of patterns on a nanodisk or imprint stamp to produce servo tracking patterns, according to one embodiment of the present invention. For example, core 1506 can be used to receive first and second materials 602 and 604 and then sliced to form an alternative first pattern 1600 of an imprint stamp or nanodisk. Pattern 1600 is altered compared to first pattern 600 shown in Figure 6 because grooves 1550 forms a "wobble" in the pattern, as discussed below. As discussed above, the servo tracking pattern 1600 on an imprint stamp or nanodisk can be used in imprint lithography to form servo tracks and data bit tracks, respectively, on a memory disk, for example.
[0122] As shown in Figure 15, a cluster of grooves 1550 is formed in a surface of a core 1506 (e.g., a quartz rod). Groves 1550 are formed at regular intervals around a circumference of core 1506 in such a way as to put a displacement into a radius of pattern 1600 that forms tracks on a memory disk. As the pattern 1600 is built up with successive layers, the displacement in what will become a track position on the memory disk is translated through all layers. For example, this displacement can be a pre-programmed "wobble" that can be changed into an AC signal that can be read and interpreted by a head to indicate whether a head is moving off right or off left of a desired data bit track position.
[0123] Figure 17 shows waveforms 1752-1756 generated by a head reading servo tracking patterns formed on a memory disk using pattern 1600, according to one embodiment of the present invention. In one example, when a head passes over a pattern cluster including servo tracking patterns on the memory disk formed by pattern 1600, the head will generate an amplitude modulation at a frequency related to rotation speed of the memory disk and the spacing of the data bits tracks formed on the memory disk using pattern 1600 on the imprint stamp during imprint lithography. This servo tracking signal can be monitored to adjust a position of the head during reading of the data bits.
[0124] In one example, the head is centered when a signal is maximized and when a signal frequency is doubled, as shown in waveform 1756. A phase of the signal generated by the head from reading the offset bits in the servo tracking pattern on the memory disk indicates whether the head is to the inside or to the outside of the data bit track radius. For example, waveform 1752 is detected when the head is to the right of the track 1550 and waveform 1754 is detected when the head is to the left of the track 1550.
[0125] In one example, a servo actuator system would receive the signals from the head and actuate movement of the head based on the signals, as would be known to a skilled artisan. For example, the servo actuator system can be a learning system that saves data of historical misalignments for future adjustment.
[0126] In one example, hard drive platens (e.g., memory disks) could have a data bit track broken up into zones and into sectors. The hard drive platen zones are tracks with varying radii. For example, an inner zone, a mid zone, and an outer zone can have a gap between the zones in terms of track positions. Then, each of the zones are divided up into sectors, like pie-shaped pieces, and the beginning and end of each sector has various read- write control data bits, which allow, for example, the amplitude of the signal to be automatically adjusted, position of the head to be adjusted. The zones may also have markers that indicate a beginning or an end of where the data is programmed in the platen. Thus, in this example, the hard drive platens are not necessarily a continuous a continuous array of data bits, rather they comprise a format structure.
[0127] It is to be appreciated that in addition to an imprint lithography system being used to form tracks and servo tracks on a memory disk, as is discussed above, an interference imager using two coherent light beams that are converged together in a fluid using immersion to form an interference grating type image on a substrate may be used to print tracks on a memory disk.
Exemplary Method
[0128] Figure 18 shows a flowchart depicting a method 1800 for forming a nanodisk having areas used to pattern data bit areas on a memory disk using imprint lithography, according to one embodiment of the present invention. In step 1802, a first annular pattern is formed that comprises alternating sections of first and second materials. In step 1804, the first annular pattern is imprinted with a second pattern to form a cross hatched pattern on the first pattern. In step 1806, portions of the first and the second patterns on the nanodisk are selectively etched.
[0129] Figure 19 shows a flowchart depicting a method 1900, according to one embodiment of the present invention. For example, method 1900 can be a method of manufacturing a memory disk. In step 1902, main tracks are formed on a disk platen. In step 1904, isolated bit areas are formed with respect to the main tracks on the disk platen. In step 1906, a magnetic layer is formed on the isolated bit areas with magnetic material to form discrete isolated data bits.
[0130] In one example, in step 1904 pits are formed in the disk platen and in step 1906 the magnetic material is deposited in the pits to form the discrete isolated data bits.
[0131] In another example, in step 1904 posts are formed on the disk platen and in step 1906 the posts are coated with the magnetic material to form the discrete isolated data bits.
[0132] In one example, in step 1908 servo tracks are formed on the disk platen, the servo tracks being located proximate one or more of the main tracks.
Exemplary Transport of Substrate for Double Sided Patterning
[0133] Figure 20 shows a portion of an imprint lithography system, according to one embodiment of the present invention. In this portion, a carrier 2000 is used to transport a substrate 2002 from one location of a lithography tool (not shown), e.g., an imprint lithography tool, to another location of the lithography tool. For example, substrate 2002 can be transported for patterning, as is described in more detail above and below. In this embodiment, substrate 2002 includes first and second resin surfaces 2004 and 2006, which can both be patterning surfaces. Thus, in order to avoid disrupting the patterning surfaces 2004 and 2006 during transport, substrate 2002 is contacted on its edge 2008 by holding portions 2010 of carrier 2000. To securely hold substrate 2002 during transport, a shape of edge 2008 is formed to be complementary with a shape of holding portion 2010, while allowing for edge 2008 to be supported by holding portions 2010. Various exemplary shapes are shown in Figure 21, 22, and 23 below. [0134] Figures 21, 22, and 23 show various complementary shapes for substrate edge 2108 and carrier holding portions 2010, according to various embodiments of the present invention. These are meant to be exemplary, and not exhaustive. [0135] Figure 21 shows a substrate 2102 having a single beveled edge 2108 being held by a holding portion 2110 of a carrier 2100 having a complementary single beveled shape, such that carrier 2100 does not touch patterning surfaces
2104 and 2106 during transport. [0136] Figure 22 shows a substrate 2202 having a double beveled edge 2208 being held by a holding portion 2210 of a carrier 2200 having a complementary double beveled shape, such that carrier 2200 does not touch patterning surfaces
2204 and 2202 during transport. [0137] Figure 23 shows a substrate 2302 having a stepped edge 2308 being held by a holding portion 2310 of a carrier 2300 having a complementary stepped shape, such that carrier 2300 does not touch patterning surfaces 2304 and 2306 during transport.
Exemplary Double Sided Patterning of Substrate
[0138] In an exemplary embodiment of the present invention, a curvature or bow is created in the imprint stamp that allows the stamp to be separated from the resin (substrate) with an unzipping action. Once separated from the stamp, the substrate can be unloaded from the apparatus in an undamaged state. The curvature or bow is instrumental in providing a clean separation of the stamp and substrate, particularly on larger substrates.
[0139] FIG. 24 is an illustration of an exemplary apparatus 2400 including imprint stamps 2402a/2402b and a double sided substrate (e.g., a resin coated patterned media disc substrate) 2404, arranged in accordance with an embodiment of the present invention. The substrate 2404 can be held in place, for example, by a patterned media carrier plate 2405. In FIG. 24 the imprint stamps 2402a and 2402b can be nano-plate imprint stamps (i.e., having nano-scale features on the orders of several nanometers line width), although other types of imprint stamps can be used. [0140] The imprint stamps 2402a and 2402b respectively include patterns
2403a and 2403b that are to be printed onto respective sides 2404a/2404b of the substrate 2404.
[0141] Each of the imprint stamps 2402a and 2402b is clamped in such a way as to create a bow in the stamp profile. In the embodiment of FIG. 24, the imprint stamps 2402a and 2402b are held by a vacuum seal 2406 against vacuum lands 2407 that are out of planar. Deviation 2408 from planar is quite small, but is sufficient to deviate a center portion 2410 of the stamps 2402a and 2402b, many microns out of flat. This bow or curvature, which has been introduced in the stamp, ensures that when each of the stamps 2402a and 2402b and the respective sides 2404a/2404b of the substrate 2404 are brought together, it is the center portion 2410 of the stamps 2402a and 2402b that makes contact with respective sides 2404a/2404b of the substrate 2404, first.
[0142] In one example, stamps 2402a and 2402b can be clamped flat onto substrate 2404 and the bowing can be produced by gas pressure (e.g., air or nitrogen) being exerted behind a plate of each of the stamps 2402a and 2402b to release stamps 2402a and 2402b from substrate 2404.
[0143] In one embodiment, the bow introduced in stamp 2402a is substantially equal to the bow introduced in stamp 2402b. In another embodiment, the amount of bowing can be different in each stamp.
[0144] In the exemplary embodiment of FIG. 24, the substrate 2404 has a bore
2412 through its center. Respective alignment markers 2414a and 2414b are provided as reference points for precisely aligning each of the stamps 2402a and 2402b respectively, to the center bore 2412 of the substrate 2404. A positioning and alignment system 2416 can then be used to perform the actual alignment of the markers 2414a and 2414b to the bore 2412. Alignment can be accomplished, for example, by first aligning the marker 2414a with the marker 2414b. Next, the bore 2412 can be aligned with the previously aligned markers 2414a and 2414b. The positioning and alignment system 2416 can be selected from a number of different lithography alignment tools.
[0145] In another example, alignment can be performed based on alignment marks 2418a-d, where alignment is made between alignment marks 2418a and 2418b and between 2418c and 2418d. [0146] As a final check and to provide a means of more finely tuning ongoing alignments, a viewing system can then be used to view the alignment markers 2414 and the bore 2412 during the alignment process.
[0147] FIG. 25 is an illustration 2500 of the stamps 2402a/2402b and the substrate 2404, shown in FIG. 24. In FIG. 25, the stamps 2402a/2402b and the substrate 2404 are shown under application of force 2502 and exposure to optional ultra-violet (UV) radiation 2504. That is, during an actual imprinting procedure, the stamps 2402a/2402b and respective sides of the substrate 2404, are simultaneously pressed together with enough force 2502 to conform the side 2404a to the stamp 2402a and the 2404b to the stamp 2402b, together in intimate contact. The applied force or pressure can result from a vacuum, hydraulic, pneumatic means, electrostatic, electromagnetic, or by a combination of some or all of these techniques.
[0148] Effectively, the bows formed in each of the stamps 2402a and 2402b, are substantially flattened out by a clamping pressure. Further clamping pressure can be applied using the vacuum seals 2414. The vacuum seals are provided to create a vacuum cavity between the sides of substrate 2404 and the imprint stamps 2402a and 2402b, respectively.
[0149] The pressure and temperature of the stamping process is controlled to provide high quality pattern transfer. The entire apparatus is enclosed in a chamber which provides temperature control. The temperature of the apparatus including the substrate is controlled to a temperature defined by the requirements of the process conditions of the applied resin.
[0150] Transfer of the patterns 2403 a and 2403b into the respective sides 2404a and 2404b can be further facilitated by optionally flood exposing, for example, a UV-cure type resin with UV light 2504 through each of the imprint stamps 2402a and 2402b and into the sides of the substrate 2404, respectively. The UV exposure 2504 cross-links the resin coated substrate 2404 and helps to solidify the resin.
[0151] Although FIG. 25 provides an illustration of a UV-curable resin coated substrate, the present invention is not limited to this approach. For example, the principle of deforming the imprint stamps 2402a and 2402b with an arc or bow is also applicable using a thermal resin. With thermal resin, the substrate and imprint mask are brought together at an elevated temperature which is sufficient to soften the resin.
[0152] When softened through heating, the patterns from the imprint stamps
2402a and 2402b respectively, can be physically pressed into the resin supplied to substrate 2404 by applying the force/pressure 2502. Using a thermal resin, no U-V exposure is required to cure the resin. Both the stamps 2402a and 2402b, and the substrate 2404 are typically heated and temperature controlled in the case of thermal imprinting.
[0153] FIG. 26 is an illustration 2600 of the imprint stamps 2402a and 2402b being separated from the sides of the substrate 2404, in accordance with an embodiment of the present invention. The release of the vacuum and reduction of the pressure 2502 between the stamps 2402a and 2402b and the sides initiates the separation process. The imprint stamp 2402a begins to separate from the first substrate side and the imprint stamp 2402b begins to separate from the second substrate side. This separation begins first as a peeling apart at the outer edge 2602a - 2602d. As discussed above, , the imprint stamps 2402a and 2402b are held by a vacuum seal 2406 against vacuum lands 2407 that are out of planar.
[0154] In another embodiment, stamps 2402a and 2402b have central apertures in them. A ball or curvature is introduced in these stamps 2402a/2402bto facilitate separation between stamps 2402a/2402b and substrate 2404. In a still further embodiment, stamps 2402a/2402b can be, but are not limited to, square or disk shaped.
[0155] The separation progresses to the center portion 2410 of the substrate
2404 in a carefully controlled manner as the pressure is fully released. There is an unzipping, or peeling back action, as opposed to a straight pull off, to separate the sides 2404a and 2404b from the imprint stamps 2402a and 2402b, respectively. This action is essential to the keeping of nanometer sized imprinted patterns transferred to the substrate 2404 in place and undamaged. Once separated from the imprint stamp 2402a and 2402b, the substrate 2404 can be unloaded from the apparatus 2600.
[0156] In one example, release agent material can be formed on the stamps or resin surface to further aid the release of the stamps from the resin. [0157J FIG. 27 is a flowchart of an exemplary method 2000 of practicing an embodiment of the present invention. In FIG. 27, first and second surfaces of an imprint stamp are deformed to produce respective first and second deformed surfaces, each having an arc therein, as indicated in step 2702. In step 2704, a pressure is applied to bring the deformed first and second surfaces into intimate contact with first and second substrate surfaces respectively, the applied pressure substantially flattening the deformed surface. To separate the two surfaces, the applied pressure is released, as indicated in step 2706.
[0158] In one example, the patterning of the first and second sides of the substrate is performed substantially simultaneously.
Another Exemplary Embodiment to Separate a Stamp
[0159] Ln an exemplary embodiment of the present invention, a curvature or bow is created in the imprint stamp that allows the stamp to be separated from the resin with an unzipping action. Once separated from the stamp, the substrate can be unloaded from the apparatus undamaged. The curvature or bow is instrumental in providing a clean separation of the stamp and substrate particularly on large substrates.
[0160] FIG. 28 is an illustration of an exemplary apparatus 2800 including an imprint stamp 2802 and a substrate (e.g., a resin) 2804 arranged in accordance with an embodiment of the present invention. In FIG. 28 the imprint stamp 2802 can be, for example, a nano-plate imprint stamp (i.e., having nano-scale features on the orders of a few hundreds of millimeters line width).
[0161] The imprint stamp 2802 includes a pattern that is to be printed onto the substrate 2804. The use of vacuums is well know in the semiconductor manufacturing art.
[0162] The imprint stamp 2802 is fastened onto a mask holder platen 2803 using vacuum lands 2806. The imprint stamp 2802 is fastened onto the mask holder platen 2803 in such a way as to create a bow in the stamp profile. In the embodiment of FIG. 28, the imprint stamp 2802 is held by vacuum against vacuum lands that are out of planar. Deviation 2808 from planar is quite small, but is sufficient to deviate a center portion 2810 of the stamp 2802 many microns out of flat. This bow or curvature, which has been introduced in the stamp, ensures that when the stamp 2802 and the substrate 2804 are brought together, it is the center portion 2810 of the stamp 2802 that makes contact with the substrate 2804 first.
[0163] The substrate 2804, which is to be impressed, is mounted onto a substrate platen 2812. The substrate platen 2812 need not be flat. That is, the substrate platen 2812 can also have a bow built into it which will also allow the central region of the substrate 2804 to meet the central portion 2810 of the stamp 2802 first.
[0164] During an actual imprinting procedure, the stamp 2802 and the substrate
2804 are pressed together with enough force 2816 to conform the entire surface of both the stamp 2802 and the substrate 2804 together in intimate contact. Effectively the bow introduced into the stamp is substantially flattened out by the clamping pressure. Further clamping pressure can be applied using a vacuum seal 2814 and then by drawing a vacuum between the substrate 2804 and the imprint stamp 2802.
[0165] FIG. 29 is an illustration 2900 of the stamp 2802 and the substrate 2804, shown in FIG. 28, being exposed to ultra-violet (UV) radiation 2902. That is, the pattern transfer into the resin 2804 can be further facilitated by flood exposing, for example, a UV-cure type resin with UV light through the imprint stamp 2802 into the substrate 2804. The UV exposure 2902 cross-links the resin 2804 and helps to solidify the resin 2804.
[0166] Although FIG. 29 provides an illustration of a UV-curable resin, the present invention is not limited to this approach. For example, the principle of deforming the imprint stamp 2802 and/or the substrate 2804 with a bow is also applicable using a thermal resin. With thermal resin, the substrate and imprint mask are brought together at an elevated temperature which is sufficient to soften the resin. When softened through heating, the pattern from the imprint stamp 2802 can be physically pressed into the softened resin 2804 by applying pressure 2904 and the pattern printed. Using a thermal resin, no U-V exposure is required to cure the resin. Both the stamp 2802 and the substrate platen 2812 are typically heated and temperature controlled in the case of thermal imprinting.
[0167] FIG. 30 is an illustration of the imprint stamp 2802 being separated from the substrate 2804 in accordance with the present invention. The release of the vacuum and reduction of the pressure 2904 between the stamp 2802 and the substrate 2804 initiates the separation process. The imprint stamp 2802 and the substrate 2804 begin to separate, or peel apart, at the outer edges 3002 and 3004 first. The separation progresses to the center portion 2810 of the substrate 2804 in a carefully controlled manner as the pressure is fully released. There is an unzipping, or peeling back action, as opposed to a straight pull off, to separate substrate 2804 and the imprint stamp 2802. This action is essential to the keeping of nanometer sized imprinted patterns transferred to the substrate 2804 in place and undamaged.
[0168] Once separated from the imprint stamp 2802 the substrate 2804 can be unloaded from the apparatus 2800. In some cases the substrate 2804 can be a disk, or a disk having a hole through its center.
[0169] FIG. 31 is a flowchart of an exemplary method 3100 of practicing an embodiment of the present invention. In FIG. 31, at least one of a surface of an imprint stamp and a substrate is deformed to provide a deformed surface having an arc therein, as indicated in step 3102. In step 3104, a clamping pressure is applied to bring the deformed surface into intimate contact with the other surface, the applied pressure substantially flattening the deformed surface. To separate the two surfaces, the applied clamping pressure is released, as indicated in step 3106.
[0170] FIG. 32 is an illustration of one exemplary technique for making a nano-plate for imprint lithography in accordance with an embodiment of the present invention. In FIG. 32, a nano-plate boule 3200 is built up, or developed, from hundreds of deposited thin film layers 3202 using a layering approach to form, for example, a ring layer structure 3203.
[0171] The nano-plate boule 3200 is constructed by depositing thin films of two or more materials 3204 and 3206 produced from two or more thin film deposition sources 3208 and 3210, respectively. The deposition of the materials 3204 and 3206 is aided by respective shutter assemblies 3212 and 3214. The materials 3204 and 3206 are deposited in an alternating manner onto the boule 3200 as it rotates in a direction 3216 around a central core 3218. FIG. 32 illustrates the boule 3200 rotating in a counter-clockwise direction for purposes of illustration only. The present invention is in no way limited to counter-clockwise rotation. The central core 3218 can be, for example, a solid rod, a hollow cylinder, or other similar structure. An exemplary diameter of the central core 3218 might be greater than about 2 millimeters (mm).
[0172] In practice, as understood by one of skill in the art, the thin film materials 3204 and 3206 can be deposited as the nano-plate boule 3200 rotates, as shown. Alternatively, however, the deposition sources 3208 and 3210 can be rotated around the central core 3218, to create the circularly symmetrical ring layer structure 3203. As illustrated in FIG. 32, the deposited film layers 3202 form separate and concentric rings within the layer structure 3203.
[0173] To form the separate concentric rings within the layer structure 3203, during deposition, one of the sources (e.g. the source 3208) will switched off while a film comprised of a first of the thin film materials (e.g., material 3206) is being deposited by the other source 3210. When the film comprised of the first material (3206) is completed, its source (3210) will be switched off and the second source (3208) will be activated to deposit the film comprised of the second material (3204). This process continues until the desired thickness of the nano-plate boule 3200 is achieved.
[0174] The deposition process noted above ultimately produces alternating layers of the materials 3204 and 3206, as illustrated in FIG. 33. The materials 3204 and 3206 can be comprised of, by way of example, silicon dioxide, silicon nitride, and/or silicon. The materials 3204 and 3206 can alternatively be comprised of heavy metallic materials, such as tungsten, molybdenum, and tantalum, to name a few.
[0175] In the example of FIG. 32, high rate magnetron biased sputtering can be used as the boule 3200 rotates. As noted above, however, it can be arranged whereby the sputter sources can be made to rotate around a stationary boule 3200. Once the boule 3200 has been built up, typically to about 85 to 90 mm in diameter, individual nano-plates can be made by slicing disks off the nano-plate boule 3200, using known slicing tools.
[0176] FIG. 34 is an illustration of an alternative approach to the circularly symmetrical ring layer structure 3203 of FIG. 32. In FIG. 34, a nano-plate boule 3400 can be developed to have rings 3402 that form a spiral structure 3404, using a baffled deposition process. To produce the spiral structure 3404, for example, each deposition source can be set such that one revolution of the boule produces the required thickness of material. If a single revolution produces the desired thickness of material, then both of the sources, for example, the sources 3208 and 3210 of FIG. 32, can be on at the same time. That is, each of the sources 3208 and 3210 would be sequentially depositing one layer on top of the other, around the boule 3400 continuously, to form the spiral structure 3404.
[0177] The thin film deposition process can be accomplished using a variety of methods well known to those of skill in the art. For example, sputter deposition, chemical vapors deposition, plasma vapor deposition or similar thin film deposition systems can be used. Deposition of the materials can be accomplished using two or more deposition sources.
[0178] The deposited thin films, such as the thin film layers 3202 of FIG. 32, can be made from many material combinations. Within the context of the present invention, it is preferable that one or more of the materials, such as the materials 3204 and 3206, be selectively etched. Additionally, the materials can be deposited in extremely smooth films, where there is no significant inter-diffusion of the layer during processing that will degrade the definition of the layer thickness. An example of readily available material combinations that can be used to form the discrete layers, and hence the rings are SiO2ZSi3N4, SiO2/Si, SiO2/Ta, and SiO2/magnetic media. There also are other exemplary suitable combinations not mentioned in the present application, but will become apparent to persons having ordinary skill in the art based on this description.
[0179] It is desirable that the deposition process be controlled to provide sufficiently smooth layers such that as the layers build up, there is no deviation from a smooth circular track. For example, bias magnetron sputter deposition can be used to maintain a very smooth deposited film surface while at the same time, achieving a high deposition rate.
[0180] Once layers have been built up, nano imprint masks, or nano-plates, can be made by cutting slices out of the boule 3200 and polishing the cut surface that will have ring structures resembling, for example, the ring sections of a tree trunk. Each tree ring section cut from the boule 3200 undergoes a polishing, or planarizing, process to provide a very flat surface. After the polishing or planarizing process, a selective etch is used to cut layers comprised of a first of the materials (e.g., 3206) selectively against layers comprised of a second of the materials (e.g., 3204). The layers are cut to a depth required for an imprint mask, typically about 40 nanometers (nm), for 30 nm lines and spaces.
[0181] FIG. 35 is a cross-sectional view of one nano-plate 3500 sliced from the circularly symmetrical ring layer structure 3203 of the boule 3200. In the nano-plate 3500, tracks, such as the tracks 3502, are formed in a polished nano-plate surface 3504 by selectively etching the film layers comprising material 3204 against the film layers comprising material 3206, as noted above. The tracks 3502 are etched to form trenches, such as the trenches 3506, in the nano-plate surface 3504. A width 3508 of the tracks 3502 can be within a range of about 1 to 100 nm. A preferable width value is on the order of about 30 nm. The width 3508 of the tracks correspond to line and space widths in the context of lithography terminology.
[0182] The trenches 3506 are formed to a depth 3510 of about 45 nm to form the 30 nm lines and spaces, noted above. The etching of the tracks 3502 to form the trenches 3506 can be accomplished using well known semiconductor etching techniques. For example, a plasma type etcher could be used to reactively etch, or vaporize, the film layers of the material 3206 to form the trenches 3506.
[0183] FIG. 36 is an illustration of an alternative nano-plate structure 3600.
The alternative nano-plate structure 3600 is rectangular in shape as opposed to the circular ring layer structure 3203 illustrated in FIG. 32. As in the case of the ring layer structure 3203, the rectangular structure 3600 includes rectangular film layers 3602 formed around a central core 3604. The sections of the boule can be cut up in various ways to form stamps with linear or curved tracks.
[0184] In the present invention, planarization can be achieved by using standard chemical mechanical polishing (CMP) processes. The planarization or smoothing can also be accomplished by sputter etching, for example, a planarizing resist coating.
[0185] As noted above, a nano-plate can be formed having a central hole or bore therethrough, by building the nano-plate boule 3200 around a hollow tube, rather than a solid rod (coolant for deposition processing can be passed through the hollow portion of the tube to control the deposition processing temperature).
[0186] Typically, quartz is used for the center of the boule although other materials can be used. The final line width and spacing is controlled by the thin layer thickness for the deposited films. Layer thickness is controlled by deposition rate and rotation rates of the boule relative to the sources.
[0187] Extremely thin nano-plates can be cut and bonded to carrier plates (not shown) to reduce costs by increasing the number of nano-plates per boule.
[0188] To provide format structures on the nano-plate 3500, the widths of the rings can be varied in a controlled manner. The formatting structures can be added to the nano-plate 3500 to enable the nano-plate 3500 to be used as a storage medium. This is achieved by using a lithographic printing process on the platen surface 3504, before etching out the tracks 3502 to form the trenches 3506.
[0189] Further to the point of magnetic media applications, the techniques of the present invention are also capable of defining the highest possible track resolutions. Track widths of 10 nm can be defined very uniformly, which is beyond the capabilities of standard optical e-beam lithography. By changing track thicknesses, lithographically printing formatting structures can be defined on the disk 3500. This method enables greater than 200 Terabyte hard drive capability.
[0190] FIG. 37 is a flowchart of an exemplary method 3700 of practicing an embodiment of the present invention. In FIG. 37, two or more types of film are deposited around a central core to form a plurality of film layers, as illustrated in step 3702. Each film layer being of a different type than its adjacent layers. In step 3704, the deposited film layers are sectioned to expose a patterned surface. The patterned surface is then planarized as indicated in step 3706 and patterns comprised of one of the types of film are selectively etched to a predetermined depth to produce a selectively etched surface, as indicated in step 3708.
[0191] FIG. 38 is an illustration of one exemplary technique of making a computer hard drive platen in accordance with an embodiment of the present invention. In FIG. 38, a boule 3800 is built up, or developed, from possibly millions of deposited thin film layers 3802 using a layering approach to form, for example, a ring layer structure 3803.
[0192] The boule 3800 is made by depositing thin films of two or more materials, such as materials 3804 and 3806, in an alternating manner onto the boule 3800 as it rotates in a direction 3808 around a central core 3810. FIG. 38 illustrates the boule 3800 rotating in a counter-clockwise direction for purposes of illustration only. The present invention is in no way limited to a counter-clockwise rotation. The central core 3810 can be, for example, a solid rod, a hollow cylinder, or other similar structure. An exemplary diameter of the central core 3810 might be greater than about 2 millimeters (mm).
[0193] The materials 3804 and 3806 are sequentially deposited using exemplary thin film deposition sources 3812 and 3814, respectively. In practice, as understood by one of skill in the art, to deposit of the materials 3804 and 3806, the boule 3800 can be rotated as shown. Alternatively, however, the deposition sources 3812 and 3814 can be rotated around the central core 3810, to create the circularly symmetrical ring layer structure 3803. As illustrated in FIG. 38, the deposited film layers 3802 form separate and concentric rings within the layer structure 3803.
[0194] To form the separate concentric rings within the layer structure 3803, during deposition, one of the sources 3812 or 3814 will switched off while a film comprised of a first of the materials 3804 or 3806 is being deposited by the other source. When the film comprised of the first material (e.g. 3804) is completed, its source (e.g., 3812) would be switched off and the second source (3814) would be activated to deposit the film comprised of the second material (3806). This process continues until the desired thickness of the boule 3800 is achieved.
[0195] The deposition process noted above ultimately produces alternating layers of the materials 3804 and 3806, as illustrated in FIG. 39. The materials 3804 and 3806 can comprise, by way of example, silicon dioxide, silicon nitride, and/or silicon. The materials 3804 and 3806 can also comprise heavy metallic materials, such as tungsten, tantalum, and molybdenum, to name a few.
[0196] In the example of FIG. 38, high rate magnetron biased sputtering was used as the boule 3800 rotated. As noted above, however, it can be arranged whereby the sputter sources can be made to rotate around a stationary boule 3800. Once the boule has been built up, typically to about 85 to 90 mm in diameter, platens can be made by slicing disks off the boule 3800, using known slicing tools.
[0197] FIG. 40 is an illustration of an alternative approach 4000 to the circularly symmetrical ring layer structure 3803 of FIG. 38. In FIG. 40, a boule 4000 can be developed to have rings 4002 that form a spiral structure 4004, using a baffled deposition process. To produce the spiral structure 4004, for example, each deposition source can be set such that one revolution of the boule produces the required thickness of material. If a single revolution produces the desired thickness of material, then both of the sources, for example, the sources 3812 and 3814 of FIG. 38, can be on at the same time. That is, each of the sources 3812 and 3814 would be sequentially depositing a layer, one layer on top of the other, around the boule 4000 continuously, to form the spiral structure 4000.
[0198] The thin film deposition process can be accomplished using a variety of methods well known to those of skill in the art. For example, sputter deposition, chemical vapors deposition, Plasma Vapor Deposition or similar thin film deposition systems can be used. Deposition of the materials can be accomplished using two or more deposition sources.
[0199] The deposited thin films, such as the thin film layers 3802, can be made from many material combinations. Within the context of the present invention, it is preferable that one or more of the material, such as the materials 3804 and 3806, be selectively etched. Additionally, the materials can be deposited in extremely smooth films, where there is no significant inter-diffusion of the layer during processing that will degrade the definition of the layer thickness. An example of readily available material combinations that can be used to form the discrete layers, and hence the rings are SiO2/Si3N4, SiOa/Si, SiO2/Ta, and SiO2 Magnetic Media Film. There also are other exemplary combinations not mentioned in the present application, but will become apparent to persons having ordinary skill in the art based on this description.
[0200] It is desirable that the deposition process be controlled to provide sufficiently smooth layers such that as the layers build up, there is no deviation from a smooth circular track. For example, bias magnetron sputter deposition can be used to maintain a very smooth deposited film surface while at the same time, achieving a high deposition rate.
[0201] To form individual magnetic disks, the boule 3800 and the boule 4000 can be cut up into disks that will have ring structures that, for example, resemble the ring sections of a tree trunk. The tree ring section platens cut from the boules undergo an initial planarization, or surface polishing, to provide a very flat surface. [0202] FIG. 41 is a cross-sectional portion (disk) 4100 of the circularly symmetrical ring layer structure 3803 of the boule 3800. In the cross-sectional portion 4100, tracks, such as the tracks 4102, are formed in a polished platen surface 4104 of the disk 4100 by selectively etching the film layer comprising material 3804 against the film layer comprising material 3806. The tracks 4102 are etched to form trenches, such as the trenches 4106, in the platen surface 4104. A width 4108 of the tracks 4102 can be within a range of about 1 to 100 nanometers (nm). A preferable width value is on the order of about 30 ran. The width 4108 of the tracks correspond to line and space widths in the context of lithography terminology.
[0203] The trenches 4106 are formed to a depth 4110 of about 45 nm to form the 30 nm lines and spaces, noted above. The etching of the tracks 4102 to form the trenches 4106 can be accomplished using well known semiconductor etching techniques. For example, a plasma type etcher could be used to reactively etch, or vaporize, the film layers of the material 3806 to form the trenches 4106. Wet selective etching can also be used.
[0204] FIG. 42 is an illustration of the cross-sectional portion 4100 of FIG. 41 having a magnetic media deposited in the trenches 4106 sections, in accordance with the present invention. In FIG. 42, the trenches 4106 in the disk platen surface 4104 are filled by coating the disk with magnetic media. The platen surface 4104 is then planarized again to leave discrete isolated tracks of magnetic media 4200 in the areas of the trenches 4106 that were etched from the tracks 4102.
[0205] Planarization can be achieved by using standard chemical mechanical polishing (CMP) processes. The planarization or smoothing can also be accomplished by sputter etching a planarizing resist coating with 1 : 1 selectively against the magnetic media 4200 coat.
[0206] As noted above, platens can be formed having a central hole or bore, by building the boule up on a hollow tube, rather than a solid rod (coolant for the deposition process can be passed through the hollow tube to control the deposition processing temperature). Typically, quartz is used for the center of the boule although other materials can be used. The final data track width and spacing is controlled by the thin layer thickness for the deposited films. Layer thickness is controlled by deposition rate and rotation rates of the boule relative to the sources.
[0207] Extremely thin nano-plates can be cut and bonded to carrier plates (not shown) to reduce costs by increasing the number of disks per boule.
[0208] To provide format structures on the disk 4100, the widths of the rings can be varied in a controlled manner. Formatting structures can be added to the disk 4100 by using a lithographic printing process on the platen surface 4104, before etching or after etching out the tracks 4102 to form the trenches 4106.
[0209] The nano-plate can be mounted on a central boss structure to ensure correct balance for high speed disk rotation. Both the upper and the lower surface of the disk can have data tracks formed on them. These upper and lower tracks will be perfectly aligned to each other
[0210] The technique of the present invention is capable at defining the highest possible track resolutions. Track widths of lOnm can be defined very uniformly which is beyond the capabilities of optical e-beam lithography. By changing track thicknesses or lithographically printing format structure can be defined on the disk. This method enables greater than 200 Terabyte hard drive capability.
[0211] FIG. 43 is a flowchart of an exemplary method 4300 of practicing an embodiment of the present invention. In FIG. 43, two or more types of film are deposited around a central core to form a plurality of film layers, as illustrated in step 4302. Each film layer being of a different type than its adjacent layers. In step 4304, the deposited film layers are sectioned to expose a patterned surface. The patterned surface is then polished as indicated in step 4306. In step 4308, the exposed patterns are selectively etched to expose patterns comprised of one of the types of film to a predetermined depth to produce a selectively etched surface. In step 4310, magnetic material is deposited within etches of the surface, as indicated in step 4310. In step 4312, the surface is planarized to form separated magnetic tracks therein.
Conclusion
[0212] While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. It is to be appreciated that the Detailed Description section, and not the
Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections can set forth one or more, but not all exemplary embodiments of the present invention as contemplated by the inventor(s), and thus, are not intended to limit the present invention and the appended claims in any way.

Claims

What is claimed is:
1. A method of forming a nanodisk, comprising:
(a) forming a first annular pattern comprising alternating sections of first and second materials;
(b) imprinting the first annular pattern with a second pattern to form a cross hatched pattern on the first pattern; and
(c) selectively etching portions of the first and the second patterns on the nanodisk.
2. The method according to claim 1 , wherein the second pattern comprises a wedge-shaped pattern comprising alternating sections of the first and second material.
3. The method of claim 2, further comprising: using silicon dioxide as the first material; and using silicon nitride as the second material.
4. The method according to claim 1 , further comprising:
(d) patterning a memory disk with the nanodisk to pattern data bit areas on a memory disk.
5. The method of claim 4, wherein step (d) results in forming the areas on the imprint stamp that are used to form at least one of holes, vias, and pits as the data bit areas on the memory disk.
6. The method of claim 4, wherein step (d) results in forming the areas on the imprint stamp that are used to form at least one of posts and raised portions as the data bit areas on the memory disk.
7. The method according to claim 1, wherein the nanodisk comprises a imprint lithography stamp.
8. The method of claim 1, wherein step (b) is performed using a second pattern that is formed at a plurality of unoverlapping positions radially around the first pattern.
9. The method of claim 1, wherein step (a) comprises: using silicon dioxide as the first material; and using silicon nitride as the second material.
10. The method of claim 1, further comprising:
(d) forming a servo tracking pattern in the first pattern that is used to pattern servo tracks on a memory disk.
11. A method of forming a wedge-shaped pattern of first and second materials using first and second thin film deposition sources, comprising: alternating passage of the first and second materials using respective first and second shutters; transmitted the first and second materials through respective first and second openings of a deposition baffle; rotating a substrate on an opposite side of the deposition baffle as the first and second deposition sources, the rotating substrate receiving the first and second materials to form successive layers of the first and second materials to thereby form a boule; and removing sections of the boule to form the wedge-shaped pattern.
12. The method of claim 11 , wherein: modifying the substrate at least one region to cause a reduced deposition rate of the first and second materials at the at least one region.
13. The method of claim 11, wherein the deposition baffle and a rotation speed of the rotating substrate control a deposition rate of the first and second materials on the substrate, such that the deposition rate for first and second materials is highest closest to a center of the substrate and slowest at edges of the substrate.
14. A nanodisk, comprising: tracks on a substrate; and selectively etched areas proximate the tracks, whereby the selectively etched areas form isolated data bit areas when the nanodisk is imprinted onto a memory platen.
15. The nanodisk of claim 14, wherein the selectively etched areas are at least one of holes, pits, or vias.
16. The nanodisk of claim 14, wherein the selectively etched areas are at least one of posts and raised structures.
17. The nanodisk of claim 14, further comprising: a servo tracking pattern positioned proximate the tracks, the servo tracking pattern being used to form servo tracks when the nanodisk is imprinted onto the memory platen.
18. A memory platen, comprising: main tracks formed by main tracks of a nanodisk; isolated data bits formed by data bit areas on the nanodisk, the data bit areas of the nanodisk being located proximate the main tracks of the nanodisk; and servo tracks formed by servo tracks of the nanodisk, the servo tracks of the nanodisk being located proximate one or more of the main tracks of the nanodisk.
19. The memory platen of claim 18, wherein the isolated data bits are holes, pits, or vias formed in a surface of the memory platen.
20. The memory platen of claim 18, wherein the isolated data bits are posts or raised portions formed on a surface of the memory platen.
21. A method of manufacturing a memory disk, comprising:
(a) forming main tracks on a disk platen;
(b) forming isolated bit areas with respect to the main tracks on the disk platen; and
(c) forming a magnetic layer on the isolated bit areas with magnetic material to form discrete isolated data bits.
22. The method of claim 21 , wherein: step (b) comprises forming pits in the disk platen; and step (c) comprises depositing the magnetic material in the pits to form the discrete isolated data bits.
23. The method of claim 21 , wherein: step (b) comprises forming posts on the disk platen; and step (c) comprises coating the posts with the magnetic material to form the discrete isolated data bits.
24. The method of claim 21 , further comprising:
(d) forming servo tracks on the disk platen, the servo tracks being located proximate one or more of the main tracks.
25. A memory disk comprising a nanodisk made with the method of claim 1.
26. A method for providing patterns formed on surfaces of first and second imprint stamps onto first and second surfaces of a substrate, the method comprising:
(a) deforming at least one of the surfaces of the first and second imprint stamps to produce a deformed surface;
(b) bringing the deformed surface into contact with one of the first and second substrate surfaces for transferring the pattern to the one of the first and second substrate surface; and
(c) releasing the deformed surface from the one of the first and second substrate surface.
27. The method of claim 26, wherein step (b) comprises using at least one of a vacuum pressure, hydraulic pressure, electromagnetic clamping, electrostatic clamping, and pneumatic pressure to bring the deformed surface into contact with one of the first and second substrate surfaces.
28. The method of claim 26, wherein steps (b) and (c) comprise: using a vacuum pressure and at least one of the hydraulic pressure and the pneumatic pressure, wherein when the hydraulic pressure or the pneumatic pressure is released the deformed surface remains in intimate contact with the first and second substrate surfaces until the vacuum pressure is released.
29. The method of claim 28, wherein release of the vacuum pressure initiates an unzipping action between the deformed surface and the respective first and second substrate surfaces.
30. The method of claim 26, wherein the arcs of the first and second surfaces have opposing vertices.
31. The method of claim 26, further comprising exposing the substrate to ultra-violet light prior to step (c).
32. The method of claim 26, further comprising: heating at least one of the deformed surface and the first and second substrate surfaces.
33. The method of claim 26, wherein the deformed surface is brought into intimate contact with the respective first and second surfaces of the substrate substantially simultaneously.
34. An apparatus for providing patterns formed on first and second surfaces of first and second imprint stamps onto first and second sides of a substrate, the apparatus comprising: a deforming device for deforming at least one of the first and second imprint stamps to become a deformed surface; and a moving device for moving the deformed surface against one of the first and second sides of the substrate so that the pattern is transferred to the one of the first and second sides of the substrate.
35. The apparatus of claim 34, wherein the arcs of the first and second surfaces have opposing vertices.
36. The apparatus of claim 34, further comprising: an exposing device that exposes the substrate to ultra-violet light.
37. The apparatus of claim 34, further comprising: a heating device that heats at least one of the first and second substrates and the first and second surfaces of the first and second imprint stamps.
38. The apparatus of claim 34, wherein a clamping pressure deforms the surfaces of the first and second imprint stamps.
39. The apparatus of claim 34, wherein the imprint stamps have a central aperture therethrough.
40. The apparatus of claim 34, wherein the imprint stamps have at least one of a rectilinear or circular shape.
41. A system, comprising: a substrate having first and second patterning surfaces and a shaped edge; a carrier having a holding portion that holds the shaped edge of the substrate, the holding surface having a shape that is complementary to the shaped edge of the substrate, such that the patterning surfaces remain untouched by the carrier; and first and second imprint stamps that form patterns on respective ones of the first and second patterning surfaces.
42. The system of claim 41, wherein: the substrate has a central opening; and the first and second imprint stamps have extensions that extend through the central opening when the first and second imprint stamps are aligned with the respective ones of the first and second patterning surfaces.
43. The system of claim 41, wherein the first and second stamps are at least one of curved or bowed.
44. The system of claim 41, wherein the shaped edge of the substrate comprises at least one of a single beveled edge, a double beveled edge, and a stepped edge.
45. The system of claim 41, further comprising: an alignment system; wherein the first and second imprint stamps include alignment marks; and wherein the alignment system detects the first and second alignment marks and aligns the first and second imprint stamps with the respective ones of the first and second patterning surfaces based on the detection.
46. The system of claim 41, wherein: the substrate disk includes a central opening; and the alignment system detects the first and second alignment marks through the central opening.
47. A system, comprising: a substrate having first and second patterning surfaces and a shaped edge; and a carrier having a holding portion that holds the shaped edge of the substrate, the holding surface having a shape that is complementary to the shaped edge of the substrate, such that the patterning surfaces remain untouched by the carrier.
48. The system of claim 47, wherein the shaped edge of the substrate comprises a beveled edge, a double beveled edge, and a stepped edge.
49. A method, comprising: transporting a substrate having first and second patterning surfaces and a shaped edge using a carrier having a holding portion that holds the shaped edge of the substrate, the holding surface having a shape that is complementary to the shaped edge of the substrate, such that the patterning surfaces remain untouched by the carrier; and forming respective first and second patterns on respective first and second sides of the substrate using first and second imprint stamps.
50. The method of claim 49, wherein the first and second patterns are formed substantially simultaneously.
51. Forming an integrated circuit using the method of claim 49.
52. Forming a flat panel display using the method of claim 49.
53. Forming a magnetic storage disk using the method of claim 49.
54. A method for imprinting a pattern formed on a surface of an imprint mask into a substrate, the method comprising: deforming at least one of the surface of the imprint mask and a surface of the substrate to produce a deformed surface having an arc therein; applying clamping pressure to bring the deformed surface into intimate contact with the other surface, the applied pressure substantially flattening the deformed surface; and releasing the applied clamping pressure.
55. The method of claim 54, further comprising exposing the substrate to ultra-violet light prior to releasing the applied clamping pressure.
56. The method of claim 54, further comprising heating at least one of the substrate and the mask prior to applying the clamping pressure.
57. An apparatus for imprinting a pattern formed on a surface of an imprint mask into a substrate, the apparatus comprising: means for deforming at least one of the surface of the imprint mask and a surface of the substrate to produce a deformed surface having an arc therein; means for applying clamping pressure to bring the deformed surface into intimate contact with the other surface, the applied pressure substantially flattening the deformed surface; and means for releasing the applied clamping pressure.
58. A method for manufacturing a nano-plate imprint mask, the nano-plate imprint mask being used to make lithographic patterns, comprising: depositing two or more types of film around a central core to form a plurality of film layers, each film layer being of a different type than its adjacent layers; sectioning the deposited film layers to expose a patterned surface; planarizing the patterned surface; and selectively etching patterns comprised of one of the types of film to a predetermined depth to produce a selectively etched surface.
59. The method of claim 58, wherein the depositing is performed in an annular fashion.
60. The method of claim 59, wherein the annular depositing forms discrete concentric rings.
61. The method of claim 58, wherein the depositing forms a continuous spiral-like structure.
62. The method of claim 58, wherein the core is a rotating spindle.
63. The method of claim 58, wherein the core is a substantially stationary spindle; and wherein deposition sources rotate around the spindle during the depositing.
64. The method of claim 58, wherein the two or more types of film include a mixture of hard metals and materials from the group including silicon, silicon dioxide, and silicon nitride.
65. The method of claim 58, wherein the two or more types of film include at least two materials from the group including silicon, silicon dioxide, and silicon nitride.
66. The method of claim 58, wherein the two or more types of film include at least two different heavy metal materials.
67. The method of claim 58, wherein each layer has a thickness of equal to or less than 30 nanometers.
68. The method of claim 58, wherein each layer has a thickness within a range of about 1 to 100 nanometers.
69. An apparatus for manufacturing a nano-plate imprint mask, the nano-plate imprint mask being used to make lithographic patterns, comprising: means for depositing two or more types of film around a central core to form a plurality of film layers, each film layer being of a different type than its adjacent layers; means for sectioning the deposited film layers to expose a patterned surface; means for planarizing the patterned surface; and means for selectively etching patterns comprised of one of the types of film to a predetermined depth to produce a selectively etched surface.
70. A method for manufacturing a hard drive platen, comprising: depositing two or more types of film around a central core to form a plurality of film layers, each film layer being of a different type than its adjacent layers; sectioning the deposited film layers to expose a patterned surface; planarizing the patterned surface; selectively etching exposed patterns comprised of one of the types of film to a predetermined depth to produce a selectively etched surface; depositing magnetic material within the etched surface; and planarizing the surface having the deposited magnetic material to form separated magnetic tracks therein.
71. An apparatus for manufacturing a hard drive platen, comprising: means for depositing two or more types of film around a central core to form a plurality of film layers, each film layer being of a different type than its adjacent layers; means for sectioning the deposited film layers to expose a patterned surface; means for planarizing the patterned surface; means for selectively etching exposed patterns comprised of one of the types of film to a predetermined depth to produce a selectively etched surface; means for depositing magnetic material within the etched surface; and means for planarizing the surface having the deposited magnetic material to form separated magnetic tracks therein.
PCT/US2005/045458 2004-12-16 2005-12-15 Systems and methods for forming nanodisks used in imprint lithography and nanodisk and memory disk formed thereby WO2006066016A2 (en)

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US11/012,474 2004-12-16
US11/012,474 US7409759B2 (en) 2004-12-16 2004-12-16 Method for making a computer hard drive platen using a nano-plate
US11/012,598 US7331283B2 (en) 2004-12-16 2004-12-16 Method and apparatus for imprint pattern replication
US11/012,489 2004-12-16
US11/012,598 2004-12-16
US11/012,489 US7410591B2 (en) 2004-12-16 2004-12-16 Method and system for making a nano-plate for imprint lithography
US11/224,316 2005-09-13
US11/224,316 US7363854B2 (en) 2004-12-16 2005-09-13 System and method for patterning both sides of a substrate utilizing imprint lithography
US11/288,135 US7399422B2 (en) 2005-11-29 2005-11-29 System and method for forming nanodisks used in imprint lithography and nanodisk and memory disk formed thereby
US11/288,135 2005-11-29

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