Abstract:
Provided herein is a method, including forming a first template including a first pattern, wherein forming the first template includes self-assembly of diblock copolymers guided by an initial pattern; forming a second template including a second pattern, wherein the second pattern corresponds to a servo pattern; and forming a master template from the first template, wherein the master template includes one or more portions of the first pattern combined with the second pattern.

Description:
CROSS-REFERENCE 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 13/097,841, filed Apr. 29, 2011, which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    In a recording system based on certain patterns, the media is fundamentally different from conventional continuous media, as the magnetic regions are laid out as periodic arrays of dots/islands where the information is stored and the region surrounding the dots is non-magnetic. Current methods to create a patterned master template for making the final media are expensive, create less efficient storage, are time consuming and take months to get results. 
       SUMMARY 
       [0003]    Provided herein is a method, including forming a first template including a first pattern, wherein forming the first template includes self-assembly of diblock copolymers guided by an initial pattern; forming a second template including a second pattern, wherein the second pattern corresponds to a servo pattern; and forming a master template from the first template, wherein the master template includes one or more portions of the first pattern combined with the second pattern. 
     
    
     
       DRAWINGS 
         [0004]      FIG. 1  shows a block diagram of an overview of a method for patterning a stack of one embodiment. 
           [0005]      FIG. 2A  shows a block diagram of an overview flow chart of a method for patterning a stack of one embodiment. 
           [0006]      FIG. 2B  shows a block diagram of an overview flow chart of a secondary master template of one embodiment. 
           [0007]      FIG. 2C  shows a block diagram of an overview flow chart of a cross track shifting to avoid partial domain dots of one embodiment. 
           [0008]      FIG. 3A  shows for illustrative purposes only an example of stack servo sectors  310  of one embodiment. 
           [0009]      FIG. 3B  shows for illustrative purposes only an example of stack  300  servo sections of one embodiment. 
           [0010]      FIG. 4A  shows for illustrative purposes only an example of a low domain dot density process of one embodiment. 
           [0011]      FIG. 4B  shows for illustrative purposes only an example of a lower dot density precursor guiding pattern of one embodiment. 
           [0012]      FIG. 4C  shows for illustrative purposes only an example of a density multiplicative guided self-assembly process of one embodiment. 
           [0013]      FIG. 4D  shows for illustrative purposes only an example of a primary imprint template of one embodiment. 
           [0014]      FIG. 5A  shows for illustrative purposes only an example of a quartz wafer of one embodiment. 
           [0015]      FIG. 5B  shows for illustrative purposes only an example of a servo pattern of one embodiment. 
           [0016]      FIG. 5C  shows for illustrative purposes only an example of fluid resist removal of one embodiment. 
           [0017]      FIG. 5D  shows for illustrative purposes only an example of etching a quartz wafer of one embodiment. 
           [0018]      FIG. 5E  shows for illustrative purposes only an example of a secondary master template of one embodiment. 
           [0019]      FIG. 6A  shows for illustrative purposes only an example of a primary imprint template of one embodiment. 
           [0020]      FIG. 6B  shows for illustrative purposes only an example of an overlay resist layer of one embodiment. 
           [0021]      FIG. 6C  shows for illustrative purposes only an example of a servo overlay process of one embodiment. 
           [0022]      FIG. 6D  shows for illustrative purposes only an example of a quartz wafer of one embodiment. 
           [0023]      FIG. 6E  shows for illustrative purposes only an example of a high density final template of one embodiment. 
           [0024]      FIG. 7A  shows for illustrative purposes only an example of unaligned domain dots of one embodiment. 
           [0025]      FIG. 7B  shows for illustrative purposes only an example of DC erasing of one embodiment. 
           [0026]      FIG. 8  shows for illustrative purposes only an example of position error signal (PES) fields of one embodiment. 
           [0027]      FIG. 9A  shows for illustrative purposes only an example of a cross track shift increment of one embodiment. 
           [0028]      FIG. 9B  shows for illustrative purposes only an example of the incremental cross track shifting of one embodiment. 
           [0029]      FIG. 10  shows for illustrative purposes only an example of servo sector reading of one embodiment. 
           [0030]      FIG. 11A  shows for illustrative purposes only an example of partial dot noise of one embodiment. 
           [0031]      FIG. 11B  shows for illustrative purposes only an example of avoided partial dot noise of one embodiment. 
           [0032]      FIG. 12  shows for illustrative purposes only an example of a cross track shifted PES field pairs operation of one embodiment. 
       
    
    
     DESCRIPTION 
       [0033]    In a following description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration a specific example in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the embodiments. 
       General Overview 
       [0034]    It should be noted that the descriptions that follow, for example, in terms of a method for patterning a stack is described for illustrative purposes and the underlying system can apply to any number and multiple types of bit patterned stack or media. In one embodiment, the manufacturing of a bit patterned stack can be implemented as bit pattered media (BPM). Bit patterned stacks use servo sectors to position the heads. In one embodiment the embedded servo patterns are created using multiple templates that reduce mastering time. In another embodiment multiple PES field pairs are created using incremental position shifts in a cross track direction and used to select the PES field pair that is positioned to avoid partial domain dot noise and produce the highest signal to noise ratio. In one embodiment an efficient method to reduce the time to develop a high quality extendible master imprint template may reduce cost and speed manufacturing of high quality BPM. It should be noted that in the descriptions that follow, the term position error signal is also represented by the capital letters PES which carry the same meaning. 
         [0035]      FIG. 1  shows a block diagram of an overview of a method for patterning a stack of one embodiment.  FIG. 1  shows a block diagram of an overview of a method for patterning a stack of one embodiment.  FIG. 1  shows a method for patterning a stack for bit patterned media creating a lower domain dot density precursor guiding pattern  100  to pattern an entire high density primary master imprint template  110 . The lower domain dot density precursor guiding pattern  100  has a low domain dot density that is very uniform with near perfect symmetry. Patterning an entire high density primary master imprint template  110  using the lower domain dot density precursor guiding pattern  100  reduces mastering time of one embodiment. 
         [0036]    The high density primary imprint template  110  is used in a servo overlay process  150 . The servo overlay process  150  embeds the servo pattern designs  120  within the high density primary imprint template  110  using a separate secondary master template  140  to form a high density final template  160 . The separate secondary master template  140  is created quickly further reducing the mastering time. The process to create the separate secondary master template  140  includes the use of an e-beam writer to position the servo pattern designs  120  on the quartz wafer that is processed to create an etched template. The e-beam writer process includes the calculation and recording of multiple PES field pairs  130 . 
         [0037]    The multiple PES field pairs  130  are positioned to read burst from the domain dots in the final servo patterns embedded within the stack media. The initial PES field pair is positioned over the servo pattern as it is transmitted to the e-beam writer. Additional PES field pairs are positioned using incremental cross track shifting relative to the initial position. 
         [0038]    The high density final template  160  is used to imprint stacks  165 . An ion beam etching process kills the magnetic properties of non-servo dots in the servo sectors on the imprinted stacks. The imprinted stacks are processed with DC erasing to realign the magnetic dots in one direction. One or more completed stacks is placed into a hard disk drive  170 . The hard disk drive  170  reads the servo bursts from the dot magnetic fields in the servo sector patterned regions and synchronously decodes the PES signals from the servo bursts. The multiple PES field pairs  130  register the PES signal from the domain dot zones in each servo section. The preamble has been locked to the phase locked loop to allow readback data to be read and decoded synchronously with the burst and operation. Each PES field pair is positioned differently along the cross track radial. These multiple locations may or may not have a boundary crossing over one or more domain dot. A readback trace is used to evaluate the multiple readback trace results  180 . A readback trace that shows a low signal to noise ratio indicated partial domain dot noise. Partial domain dot noise is an indicator that the boundaries of the PES field pair crosses over one or more domain dot. The evaluation of the readback trace showing a low signal to noise ration may disable PES field pairs with partial domain dot noise  185 . The readback trace evaluation may enable the PES field pair with the highest signal to noise ratio  190 . The method for patterning a stack reduces mastering time for a master template, is cost effective and provides accurate positioning of the servo pattern guided head for high quality and reliable read operations using a patterned stack such as bit-patterned media. 
         [0039]      FIG. 2A  shows a block diagram of an overview flow chart of a method for patterning a stack of one embodiment.  FIG. 2A  shows a time saving step in the method for patterning a stack. The fabrication of the lower density precursor guiding pattern  100  is a layer of spun resist  200  on a non-magnetic substrate  202 . The resist is processed with an e-beam writer  204  to pattern a low domain dot density for example 250 Gdpsi. The resist  200  includes for example positive and negative types of resist materials. The positive results in pillars being formed and the negative results in holes or cylindrical recesses. The lower density precursor guiding pattern  100  is the pattern guide for a multiplicative guided self-assembly process  210  such as diblock copolymer. The multiplicative guided self-assembly process  210  doubles the number of dots in both direction thereby quadrupling the density to 1,000 Gdpsi or 1 Tdpsi. The multiplicative guided self-assembly process  210  increases the density patterning an entire high density primary imprint template  220 . The high density primary imprint template  160  is used in processes that continue in  FIG. 2B . The use of the lower starting dot density reduces the mastering time. The lower density precursor guiding pattern  100  is very uniform and has near perfect symmetry. This method is cost effective and speeds the overall production. 
         [0040]      FIG. 2B  shows a block diagram of an overview flow chart of a secondary master template of one embodiment.  FIG. 2B  shows the separate secondary master template  140  of  FIG. 1  being fabricated using spun resist  200  on top of a clear quartz wafer  230 . The designed servo patterns  120  are loaded into the e-beam writer  204  to guide the operation. The e-beam writer  204  generates bursts of beams filling the servo patterns and their boundaries onto the resist  200 . The electron beams harden the resist duplicating the servo patterns. The area of the resist  200  outside the boundaries of the servo patterns remain fluid. When the e-beam writer  204  has completed patterning the entire clear quartz wafer  230  servo sectors the uncured fluid resist  200  is removed. The surface of the clear quartz wafer  230  is exposed after the removal of the fluid resist  200 . 
         [0041]    The positions of the servo patterns  120  being processed by the e-beam writer  204  are recorded. The recorded servo pattern designs  120  positioning is used to create multiple PES field pairs  130 . The PES field pairs are used to receive the readback signals from areas of the servo patterns. Each pair of the PES field pairs are oriented 90 degrees to one another in relation to the track direction. The positioning of each set of PES field pairs is adjusted to incrementally cross track shift PES field pairs  256 . The cross track shift increment includes for example ¼ of the domain dot diameter. Two or more PES field pairs are created including the initial position of the servo patterns used to guide the e-beam writer. The PES field pairs are used in the processes that continue in  FIG. 2C . 
         [0042]    The e-beam writer  204  and resist  200  lead to the cure and remove uncured fluid resist  240  processes. The surface of the clear quartz wafer  230  is exposed and ready to etch the clear quartz wafer  242 . The exposed surface unprotected by the hardened resist  200  is etched using for example ion-beam etching. The hardened resist  200  is removed upon completion to the etching. The topography created by the etching creates a servo patterned clear quartz wafer  244 . The servo patterned clear quartz wafer  244  is inverted to form a mirrored secondary master template  246 . The previous process in  FIG. 2A  places the high density primary imprint template  160  of  FIG. 1  into a servo overlay process  248 . 
         [0043]    A layer of resist  200  is spun on top of the high density primary imprint template  160  of  FIG. 1 . The mirrored secondary master template  246  is set into the resist  200 . The etched areas of the inverted mirrored secondary master template  246  are filled by capillary action with the fluid resist  200 . The non-etched areas sit on a thin film of the resist  200  close to the surface of the high density primary imprint template  160  of  FIG. 1 . UV light is projected through the back of the clear quartz wafer  230  to cure and harden the resist  200 . The hardened resist is etched. The pillars of the high density primary imprint template  160  of  FIG. 1  are etched for example in the low thin film resist  200  areas the pillars are etched to the surface of the non-magnetic substrate  202  of  FIG. 2A  and the pillars within the servo boundaries are not. This creates the high-density final template  254  for imprinting the embedded servo patterns  250 . The high-density final template  254  is used to imprint stacks  165 . An ion beam etching  252  process is used to kill magnetic properties of non-servo dots  254  in the imprinted stacks. The imprinted stacks are used in processes that continue in  FIG. 2C . 
         [0044]      FIG. 2C  shows a block diagram of an overview flow chart of a cross track shifting to avoid partial domain dots of one embodiment.  FIG. 2C  shows the continuation of the processes from  FIG. 2B . The imprinted stacks with the embedded servo patterns  250  undergo a constant magnetic field such as DC erasing  258  to realign the magnetic properties in one direction. One or more imprinted stacks are placed into the hard disk drive  170 . The multiple PES field pairs  130  including the incrementally cross track shift PES field pairs  256  are set up in the hard disk drive  170 . The preamble is locked with a phase locked loop  260  to synchronously decode the multiple PES bursts  262 . 
         [0045]    The hard disk drive  170  proceeds to read servo sectors  266 . The magnetic fields of the domain dots in the servo sectors  266  produces PES bursts  268 . 
         [0046]    The head in the hard disk drive reads the PES bursts  268  as a readback signal. The multiple PES field pairs  270  receive the readback signals. The electronics in the hard disk drive  170  synchronously decode the multiple PES bursts  262  and readback signals received by the multiple PES field pairs  270 . The readback signals are used to evaluate the multiple results in a readback trace  274 . Minimum noise criteria  272  are adjustable and established for use in the evaluation. PES burst that are read from domain dots that are crossed by the boundary of a PES field create modulation or partial domain dot noise. The partial domain dot noise  278  received by any of the PES field pairs  276  are registered as a low signal to noise ratio  280 . The low signal to noise ratio  280  indicates high partial domain dot noise  278  thereby lowering the ratio. The low signal to noise ratio  280  evaluation is that minimum noise criteria have not been met  282 . The position of the PES pair boundary crosses over domain dots creating the partial domain dot noise. Any of the PES pairs where low signal to noise ratio  280  data is received may disable those PES field pairs  284 . The multiple PES field pairs positioning having been incrementally cross track shifted may produce at least one pair whose boundaries do not cross over domain dots. The PES field pair that shows the highest signal to noise ratio  290  may indicate that minimum noise criteria have been met  292 . The highest signal to noise ratio  290  may enable PES burst pair  294 . The selection process of the PES field pair with the highest signal to noise ratio  290  provides accurate position error signals used to reposition the head. This may prevent read errors while using the patterned stack. The method for patterning a stack is a cost effective, time savings and effective method of patterning a stack and increasing production of patterned stacks and media such as bit-patterned media. 
       Servo Patterns 
       [0047]      FIG. 3A  shows for illustrative purposes only an example of stack servo sectors  310  of one embodiment. The method of patterning a stack  300  is the patterning of the servo sectors  310  of a stack  300 . The servo sectors  310  are wedge shaped servo sector  340  areas that project outwardly in a radial position from the center of for example a disk shaped stack  300 . The servo sectors  310  are spaced evenly, around the circular stack  300  leaving open other data sectors  320  between servo sectors  310  as shown in  FIG. 3A . The wedge shaped servo sectors  310  are islands of domain dots used to store data such as Gray code, SAM and provide PES feedback. The Gray code for example includes 20-bit binary code data used to identify the positions of tracks and sectors. The Gray code is written into the servo sectors  310 . The instructions are written into domain dot servo islands located in each track as shown in servo sector detail  330  of  FIG. 3B . 
         [0048]      FIG. 3B  shows for illustrative purposes only an example of stack  300  servo sections of one embodiment.  FIG. 3B  shows a portion of the stack  300  that is divided into servo sectors  310  and other data sectors  320 . The servo sector detail  330  illustrates the wedge shaped servo sector  340  that is divided by the tracks in to multiple servo section  350  regions. The servo patterns are embedded in each servo section  350 . The electronics in the hard disk drive use feedback from the heads, which read the Gray code pattern, to very accurately position, and constantly correct the radial position of the appropriate head over the desired track, at the beginning of each servo section  350 , to compensate for variations in platter geometry, caused by mechanical stress and thermal expansion and contraction. The PES feedback to the head establish the actual position of the head which is compared to the designed position in the Gray code embedded servo patterns. Partial domain dot noise can increase errors in the reading of the Gray code and PES. Position errors create errors in the search and placement of data which can lead to loss or inaccessibility to retrieve data. A portion of the Gray code is embedded at the start of each sector which is referred to as an embedded servo pattern. The embedded servo pattern data is permanent. The permanent nature of the data thereby means position errors caused by partial domain dot noise can also be permanent. The accuracy of the servo patterns created by the avoided partial domain dot results of the method to pattern a stack  300  provides the permanent position error free environment for this permanent data record on a stack  300 . 
       Low Density Precursor Guiding Pattern 
       [0049]      FIG. 4A  shows for illustrative purposes only an example of a low domain dot density process of one embodiment.  FIG. 4A  shows the non-magnetic substrate  400  on top of which is spun a layer of resist  410 . An e beam writer projected electron beams  420  to pattern the resist and substrate. 
         [0050]      FIG. 4B  shows for illustrative purposes only an example of a lower dot density precursor guiding pattern of one embodiment. The substrate  410  has a low domain dot density pattern  430  created by the e beam writer. The low domain dot density pattern  430  on the substrate  410  forms a lower dot density precursor guiding pattern  440 . The low density precursor guiding pattern  440  density can be for example 250 Gdpsi. 
       Multiplicative Guided Self Assembly 
       [0051]      FIG. 4C  shows for illustrative purposes only an example of a density multiplicative guided self-assembly process of one embodiment. On top of the low density precursor guiding pattern  440  is sputtered  450  a clear plastic  410  such as a copolymer for example Polymethyl Methacrylate. The clear plastic  410  chemically treats the dots of the low density precursor guiding pattern  440 . The density multiplicative guided self-assembly process doubles the dots in both directions in a hex pattern. The chemically treated dots and structure are baked and the clear plastic is lifted off to reveal the higher density of dots. The multiplicative process such as diblock copolymer doubles the number of dots in both 90 degree directions thereby quadrupling of the density. 
       Primary Imprint Template 
       [0052]      FIG. 4D  shows for illustrative purposes only an example of a primary imprint template of one embodiment. The results of the guided process using the low dot density precursor guiding pattern  440  of  FIG. 4B  creates a pattern with higher density  460 . The pattern with higher density  460  forms a primary imprint template  470  with a domain dot density for example 1,000 Gdpsi or 1 Tdpsi of one embodiment. 
       Secondary Master Template 
       [0053]      FIG. 5A  shows for illustrative purposes only an example of a quartz wafer of one embodiment.  FIG. 5A  shows the creation of the separate secondary master template  140 . The substrate is a clear quartz wafer  500 . Fluid resist  510  is applied over the entire surface of the clear quartz wafer  500 . 
         [0054]      FIG. 5B  shows for illustrative purposes only an example of a servo pattern of one embodiment.  FIG. 5B  shows an e beam writer projecting electron beams  520  by following the servo pattern  530 . The EBW directs beams  520  in the areas outside of the servo pattern  530  to harden the fluid resist  510  on the clear quartz wafer  500  where wanted according to the servo pattern  530  used to guide the EBW. 
         [0055]      FIG. 5C  shows for illustrative purposes only an example of fluid resist removal of one embodiment. The resist  510  in the areas inside the servo pattern  530  is still fluid on the clear quartz wafer  500 . The fluid resist  510  is removed with a cleaning process that washes away the still fluid resist  510 . This leaves the surface of the clear quartz wafer  500  uncovered in the non-hardened resist areas  540 . 
         [0056]      FIG. 5D  shows for illustrative purposes only an example of etching a quartz wafer of one embodiment.  FIG. 5D  shows the resist  510  was removed from the non-hardened resist areas  540  of the clear quartz wafer  500 . The surface of the clear quartz wafer  500  is etched  550  removing a portion of the quartz material inside the servo pattern  530  areas. 
         [0057]      FIG. 5E  shows for illustrative purposes only an example of a secondary master template of one embodiment.  FIG. 5E  shows the hardened resist  510  is removed. This leaves topography of lower etched  550  servo pattern island areas and raised areas on the clear quartz wafer  500  surfaces of the secondary master template  140  in the servo sectors. The secondary master template is inverted to use in a servo overlay process of one embodiment. 
       Servo Overlay Process 
       [0058]      FIG. 6A  shows for illustrative purposes only an example of a primary imprint template of one embodiment. The servo overlay process  150  of  FIG. 1  begins with a primary imprint template  600 . The primary imprint template  600  has a high domain dot density such as 1 Tdpsi. 
         [0059]      FIG. 6B  shows for illustrative purposes only an example of an overlay resist layer of one embodiment. On top of the primary imprint template  600  is spun an overlay resist layer  610 . The overlay resist layer  610  is spun with sufficient volume to fill the etched areas of a secondary master template  140  of  FIG. 1 . 
         [0060]      FIG. 6C  shows for illustrative purposes only an example of a servo overlay process of one embodiment. Set into the overlay resist layer  610  spun on top of the primary imprint template  600  is the secondary master template  140 . The secondary master template  140  is inverted to create a mirrored image of the servo patterns  620  etched into the surface of the clear quartz wafer  500  surface. The fluid resist fills the etched areas by capillary action. The resist pressed by the bottom surface of the secondary master template  140  forms a thin film  640 .  FIG. 6C  shows in the illustration the front side of the primary imprint template  600  transparent to reveal the pillar structure  630  of the domain dots on top of the substrate  410 . 
         [0061]      FIG. 6D  shows for illustrative purposes only an example of a quartz wafer of one embodiment. The overlay resist layer  610  has filled the etched areas of the mirrored servo patterns. Ultra violet (UV) light  660  is projected through the back of the clear quartz secondary master template  140  of  FIG. 1 . The UV light  660  sets or cures the resist forming a hard resist layer with the mirrored topography of the secondary master template  620 . The UV light  660  sets or cures the resist thin film  640  that is in contact with the surface of the primary imprint template  600  with the pillar structure  630  of the domain dots and primary imprint template hardened resist  650  on top of the substrate  410 . 
       High Density Final Template 
       [0062]      FIG. 6E  shows for illustrative purposes only an example of a high density final template of one embodiment. Ion beam etching is used to remove the hardened overlay resist layer  610 . The Ion beam etching also removes the pillar structure  630  material that forms the domain dots under the thin film  640  of resist. The thicker raised mirrored topography of the secondary master template  620  is not removed. The high density final template  695  is used to imprint stacks  165  of  FIG. 1  of one embodiment. 
       DC Erasing 
       [0063]      FIG. 7A  shows for illustrative purposes only an example of unaligned domain dots of one embodiment.  FIG. 7A  shows a patterned stack servo section  700 . The patterned stack servo section  700  includes the killed dots  680  with magnetic properties removed by ion beams. The patterned stack servo section  700  indicates the servo pattern boundary  670  within which there are domain dots with non-realigned magnetic fields  690 . The domain dots with non-realigned magnetic fields  690  are characterized by magnetic properties that are cancelling each other or producing random results. The magnetic fields are realigned using a constant magnetic field as shown in  FIG. 7B  of one embodiment. 
         [0064]      FIG. 7B  shows for illustrative purposes only an example of DC erasing of one embodiment.  FIG. 7B  shows the patterned stack servo section  700 . The patterned stack servo section  700  includes the killed dots  680  with magnetic properties removed by ion beams. The patterned stack servo section  700  indicates the servo pattern boundary  670  within which there are pillar structured domain dots. The patterned stack servo section  700  is placed in a constant magnetic field such as DC erasing  710 . The domain dots with non-realigned magnetic fields  690  of  FIG. 7A  are effected by the constant magnet field and the magnetic properties are realigned in one direction and restore clear magnetic responses. The domain dots with magnetic fields realigned  730  then have magnetic properties that can be used for read write operations. This process produces a DC erased patterned stack servo section  720 . The DC erased patterned stack servo section  720  realignment is produced on the entire stack. After DC erasing  710  the stack for example a bit-patterned media can be placed in a hard disk drive for read write operations of one embodiment. 
       PES Fields 
       [0065]      FIG. 8  shows for illustrative purposes only an example of PES fields of one embodiment.  FIG. 8  shows the relative position of the PES fields to the DC erased patterned stack servo section  720 . During the process to create the secondary master template  140  of  FIG. 1  the EBW the multiple PES fields are established. The PES fields are electronic device in the head. A PES field A  800  is combined with a PES field B  810  set at 90 degrees from PES field A  800  from to form a PES field pair  820 . The position of the PES field pair  820  is over the DC erased patterned stack servo section  720  to register readback from positioning bursts made during read write operations of one embodiment. 
       Cross Track Shift Increment 
       [0066]      FIG. 9A  shows for illustrative purposes only an example of a cross track shift increment of one embodiment.  FIG. 9A  shows a domain dot  900  such as those on the DC erased patterned stack servo section  720  of  FIG. 7B . Two or more sets of PES fields are defined to register the readback signals received from the servo sections  350  of  FIG. 3B . The positioning of each set of PES field pairs is shifted across a track direction  920  using a shift distance equal to one cross track shift increment  910 . The cross track shift increment  910  is adjustable and includes for example a one-quarter (¼)  919  domain dot  900  diameter increment of one embodiment. 
       Incremental Cross Track Shifting 
       [0067]      FIG. 9B  shows for illustrative purposes only an example of the incremental cross track shifting of one embodiment. The creation of the secondary master template  140  of  FIG. 1  includes during the servo pattern designs  120  positioning using the e beam writer  204  of  FIG. 2A  the positions of the PES fields are recorded. The position of the initial PES field pair A-B  930  is the position of the servo pattern. Additional PES field pairs are shifted in the radial direction across the track direction  920  of  FIG. 9A  by one cross track shift increment  910 . 
         [0068]      FIG. 9B  shows four PES field pairs PES field pair A-B  930 , PES field pair C-D  940 , PES field pair E-F  950 , and PES field pair G-H  960 . PES field pair A-B  930  is a set of two field pairs PES field A  932  and the second set at a  90  degree orientation from the first PES field B  934 . PES field pair A-B  930  is positioned at the initial servo pattern position. PES field pair C-D  940  is a set of two field pairs PES field C  942  and the second set at a 90 degree orientation from the first PES field D  944 . PES field pair C-D  940  is positioned one cross track shift increment  910  from PES field pair A-B  930 . PES field pair E-F  950  is a set of two field pairs PES field E  952  and the second set at a  90  degree orientation from the first PES field F  954 . PES field pair E-F  950  is positioned one cross track shift increment  910  from PES field pair C-D  940 . PES field pair G-H  960  is a set of two field pairs PES field G  962  and the second set at a 90 degree orientation from the first PES field H  964 . PES field pair G-H  960  is positioned one cross track shift increment  910  from PES field pair E-F  950 . 
         [0069]    The initial servo pattern positioned PES field pair A-B  930  may or may not have boundaries that cross over a domain dot  900  of  FIG. 9A . If it does it may receive partial domain dot noise. The PES field pairs positioned cross track by one cross track shift increment  910  may or may not receive partial domain dot noise. Minimum noise criteria is adjustable and for example evaluate partial domain dot noise that is generated by a percentage=&gt;75% of the dot is exposed to a burst to be unacceptable or by a percentage&lt;50% of the dot is exposed to a burst (the sweet spot) is exposed it does not register and is acceptable. The cross track shifting may allow selection of the PES field pair that records the highest signal to noise ratio indicating avoided partial domain dot noise of one embodiment. 
       Servo Sector Reading 
       [0070]      FIG. 10  shows for illustrative purposes only an example of servo sector reading of one embodiment.  FIG. 10  shows the stack  300  patterned using the high density final template  160  of  FIG. 1  and configured as a stack disk placed in the hard disk drive  170 . The head of the hard disk drive  170  includes the four PES field pairs including PES field pair A-B  930 , PES field pair C-D  940 , PES field pair E-F  950  and PES field pair G-H  960 . The preamble is locked with a phase locked loop  260  to allow synchronous decoding of the PES burst signals. The continuous servo patterning  264  process begins to read the head position using the information in the servo sectors  310  of  FIG. 3A  of one embodiment. 
         [0071]      FIG. 11A  shows for illustrative purposes only an example of partial dot noise of one embodiment. The stack  300  of  FIG. 3A  has been put into the hard disk drive  170  of  FIG. 1 . The mechanical systems  1110  in the hard disk drive  170  of  FIG. 1  reads a PES burst  1120 . The head in the hard disk drive  170  serially reads the magnetic fields of the dots in the embedded servo pattern designs in the servo sectors. The magnetic fields are referred to as “servo bursts”. The dots that have been killed emit a weak magnetic field that is flipping and these create a white noise that is registered in the readback trace. Partial domain dots of crossed by the PES field boundaries increase the level of noise in addition to the white noise. The PES burst  1120  produces a position error signal (PES). The PES is received by the multiple PES field pairs  130  of  FIG. 1 . The 90 degree orientation of the PES field pair provides the trigonometric sine and cosine values of the PES. Those values are synchronously decoded and recorded in a readback trace  1112 . The PES bursts cause a magnetic response in the domain dots. The PES received by a PES field pair  1100  may generate partial domain dot noise  1130  if the boundary of the PES field pair crosses a domain dot  1140 . Partial domain dot noise  1130  may register a low signal to noise ratio on the readback trace  1112  which may indicate a high level of partial domain dot noise  1130 . When the boundary of the PES field pair  1100  does not cross a domain dot  1160  or the PES field pair  1100  does not extend over a domain dot  1150  no partial domain dot noise  1130  is registered. The readback trace synchronously received data is used to turn off those PES field pairs that receive low signal to noise ratios indicating partial dot erasures. 
         [0072]      FIG. 11B  shows for illustrative purposes only an example of avoided partial dot noise of one embodiment. The mechanical systems  1110  in the hard disk drive  170  of  FIG. 1  generate a PES burst  1120 . The PES burst  1120  produces a position error signal (PES). The PES is received by the multiple PES field pairs  130  of  FIG. 1 . The 90 degree orientation of the PES field pair provides the trigonometric sine and cosine values of the PES. Those values are synchronously decoded and recorded in a readback trace  1112 . The PES bursts cause a magnetic response in the domain dots. 
         [0073]    The position of the PES field pairs  1170  in  FIG. 11B  has been cross track shifted by 3 units of the cross track shift increment  910  of  FIG. 9A . The cross track shifting has aligned the boundaries of the PES field pairs  1170  to avoid crossing a domain dot  1160 . The avoidance of a partial domain dot eliminates or reduces the partial domain dot noise  1130  of  FIG. 11A . The lower level of noise received in the readback trace  1112  may produce the highest signal to noise ratio. The readback trace synchronously received data is used to turn off those PES field pairs that receive low signal to noise ratios indicating partial dot erasures. In the example shown in  FIG. 11B  the PES field pairs  1170  may not be turned off. The cross track shifting avoids partial domain dot noise  1130  of  FIG. 11A  and the PES information may provide accurate positioning of the head using the data in the servo sectors. 
       Cross Track Shifted PES Field Pairs Operation 
       [0074]      FIG. 12  shows for illustrative purposes only an example of a cross track shifted PES field pairs operation of one embodiment.  FIG. 12  shows for example four PES field pairs including PES field pair A-B  930 , PES field pair C-D  940 , PES field pair E-F  950  and PES field pair G-H  960 . The domain dot zones from which the PES field pair receives the PES lie along a track. PES field pair A-B  930  is in the initial positioning  1200 . The pair boundaries cross over domain dots. The PES signals received by four PES field pairs are synchronously decoded and recorded in the readback trace  1280 . 
         [0075]    The PES signals received by PES field pair A-B  930  indicates increased levels  1202  of partial dot noise  1240 . This may cause a low signal to noise ratio. The electronic systems in the hard disk drive  170  of  FIG. 1  may disable  1250  PES field pair A-B  930 . 
         [0076]    PES field pair C-D  940  is in a position that includes cross tract shift no. 1¼ dot size  1210 . This one unit of the cross track shift increment  910  of  FIG. 9A  shift positions the boundaries so that they also cross over domain dots. The PES signals received by PES field pair C-D  940  indicates increased levels  1212  of partial dot noise  1240 . This may cause a low signal to noise ratio. The electronic systems in the hard disk drive  170  of  FIG. 1  may disable  1250  PES field pair C-D  940 . 
         [0077]    PES field pair E-F  950  is in a position that includes cross tract shift no. 2¼ dot size  1220 . This two unit of the cross track shift increment  910  of  FIG. 9A  shift positions the boundaries so that they also cross over domain dots. The PES signals received by PES field pair E-F  950  indicates increased levels  1222  of partial dot noise  1240 . This may cause a low signal to noise ratio. The electronic systems in the hard disk drive  170  of  FIG. 1  may disable  1250  PES field pair E-F  950 . 
         [0078]    PES field pair G-H  960  is in a position that includes cross tract shift no. 3¼ dot size  1230 . This three unit of the cross track shift increment  910  of  FIG. 9A  shift positions the boundaries so that they do not cross over domain dots. The PES signals received by PES field pair G-H  960  indicates decreased noise levels  1232  indicating partial dot noise  1240  has been avoided. This may cause a high signal to noise ratio. The electronic systems in the hard disk drive  170  of  FIG. 1  may leave enabled  1270  PES field pair G-H  960 . 
         [0079]    The operations and results of the cross track shifting provide accurate positioning of the head using the information recorded in the servo sectors  310  of  FIG. 3A . The method for patterning a stack reduces mastering time in a cost effective manner. The time and cost saved and the increased accuracy creates increased production of quality patterned stacks. 
         [0080]    The foregoing has described the principles, embodiments and modes of operation of the present invention. However, the invention should not be construed as being limited to the particular embodiments discussed. The above described embodiments should be regarded as illustrative rather than restrictive, and it should be appreciated that variations may be made in those embodiments by workers skilled in the art without departing from the scope of the present invention as defined by the following claims.