KR20010071139A - Storage disk comprising depressions and/or raised features - Google Patents

Abstract

The data storage disk includes recessed portions 215 or raised shapes that can be filled and / or polished with various materials 630.

Description

Storage discs with depressions or raised shapes {STORAGE DISK COMPRISING DEPRESSIONS AND / OR RAISED FEATURES}

Storing data on a rotating storage medium requires position sensing information to be included on a portion of the surface of the medium so that the data can be accurately accessed using the medium.

Conventional Winchester magnetic storage systems use magnetic signals stored within the thin film media surface for this purpose. The position sensing signal is generally recorded by the same system used to write data on its surface in a known process such as servo writing. The position sensing signal is recorded on the medium by an external servo writer providing track identification and position, which is then used to accurately position the flying head during this operation during the writing and reading process. In general, data is arranged in a concentric series of tracks, each track consisting of a number of sectors, each of which contains several bits of binary data. Since the position sensing information is recorded simultaneously on each recording surface on one disk of the storage medium, the time required to complete the servo write process increases as the total number of disks, sectors and tracks increases.

For example, in an optical data storage system using an optical disk such as a CD or the like, diffraction information obtained from light reflected from the disk can be used to provide position sensing information.

In other optical data storage systems embossing may be used. Here, the servo sector information can be written using an optical lithographic system. A series of pit can be formed and replicated on the surface of the metal mold. Many plastic disks having an exact copy of this pattern can be formed by a molding process. Since the molding operation is fast and inexpensive, complete servo information is provided on the entire disk surface using this inexpensive process, which eliminates the writing of individual sector information on the disk.

Pits in such optical systems are generally required to have tolerances of very tight dimensions in order to perform correctly for their intended use. For example, the depth of the pit is controlled to a particular portion of the wavelength of the light used, for example 650 nm wavelength light. The observed servo signal can be caused by harmful interference generated between the light reflected at the pit, and the change in the pit depth causes a change in the magnitude of the reflected optical signal. Since interference is used to generate the signal, a significant lateral change in spot size causes adjacent pitch edges to overlap effectively, which reduces the size of the servo signal and distorts the shape. Thus, accumulation of contaminants at the pit serves to reduce the magnitude of the reflected signal. The presence of the pit also reduces the smoothness of the disk and thus causes head flight problems for the head intended to fly near the surface of the media surface.

Optical devices are used to deliver light to provide thermally assisted recording and reading of data on magnetic disks, where magnetic and optical techniques are combined. In this type of magneto-optical system, the pit is also provided for servo tracking in the manner described above. However, applying light to the storage disk can cause undesirable thermal effects within the storage disk.

Accordingly, what is needed is a method and apparatus that serve to reduce unwanted effects and heat of the pit in a magnetic-storage drive of the prior art.

FIELD OF THE INVENTION The present invention relates generally to storage media, and more particularly to storage media using depressions or raised shapes.

1 shows a data storage system of a basic element.

2A shows in detail the disc of the present invention.

2B shows a typical servo sector.

Figure 2C shows a diagram of the storage and readout layer of the present invention.

3 is a block diagram illustrating an exemplary optical path.

4A-4N show the head of the present invention.

5 shows a storage and readout layer of the present invention.

6A-6D show steps for forming a servo pattern.

7A and 7B show signals from the servo pattern.

8A shows a substrate having a raised shape and a recessed shape.

8B-8E show simulations and channels for heat diffusion resulting from the application of an outward laser beam to a medium comprising no channel and a medium comprising no channel.

9A-9E illustrate the formation of a disk including mesas and raised shapes.

9F-9I show temperature profiles in disks with mesas and disks without any mesas.

Summary of the Invention

The present invention provides an increase in the storage capacity of a data disc drive while simultaneously reducing the overall complexity and complexity of the optics, electronics and / or associated write / read heads in the optical path. The system uses the light transmitted by the optical elements to servo track the data disc and to heat the data disc during writing and reading data, and uses individual magnetic elements for actual writing and reading. do.

Data storage disks can include recessed and raised shapes, which can be filled and / or polished by various techniques. In this way, a smooth surface is provided to the write and read head that is maintained aerodynamically in flight conditions very close to the data disk surface. By providing a smooth surface, accumulation of contaminants can be reduced or eliminated. The fill material is formed to be reflective, thereby providing increased amplitude in the optical signal reflected from depressions and / or raised shapes. Light reflections from materials used to fill depressions and / or raised shapes can be used for sector recognition and track following. Additionally, depressions and / or raised shapes may be formed to provide reflective areas that are proportional to the radius of the data disc on which they are disposed. As a result, the frequency content and amplitude change of the reflected optical signal can be minimized with respect to the radius of the data disc.

In the present invention, the data storage disk further includes. Channels and / or mesas can be used to thermally channel and guide the thermal effects of light applied to a data disc, so that the shape of the data domain mark used to store data along the data track is intersecting with the track. Direction and may be defined to more accurately match a preferred square or square shape. Storage density and SNR consequently increase. The channel and / or mesa may be filled with a filling material.

The present invention includes the formation of a master pattern for recessed or raised shapes and includes the continuous transfer of the pattern onto a disk substrate. On top of the surface, at least one sacrificial layer is provided on top of the relatively hard layer. By sacrificial layer it is meant that the layer is relatively easy to etch and otherwise removed to a controlled planar level. By hard layer it is meant that the layer becomes a relatively abrasive or etch resistor.

For example, in a magnetic-optical design, a recording stack is provided on top of silicon nitride and dioxide, and the silicon dioxide layer serves as a sacrificial layer to ensure that the hard layer of silicon nitride layer remains to the end of the treatment. do. Alternatively, a layer of aluminum or aluminum alloy may be deposited, the aluminum plug being at a level higher than any of the depressions or adjacent layers of silicon dioxide, silicon nitride or dielectric layers and similar materials (with embossed servo information). Filled shape). Since the polishing rate of aluminum is much faster than the polishing rate of silicon dioxide, aluminum can be etched or otherwise removed together with silicon dioxide to the same or slightly lower level of the silicon plane, and the silicon dioxide layer is slightly smaller Allow excessive polishing of levels. Thus, the silicon nitride layer is preferably protected; Silicon dioxide is partially present and partially removed; The aluminum metal filling the pit rises only up to substantially the same level as the flat top surface of silicon dioxide.

Alternative filling materials can be used in similar treatments as long as the appropriate selective removal treatment is useful with sufficient selectivity. In this example, aluminum serves as a sacrificial layer; The silicon backside effectively serves as a rigid layer; It is removed more slowly. In an alternative embodiment, the silicon dioxide layer is removed, which becomes a rigid layer. In conventional magnetic recording discs, the depressions or raised shapes may be filled with glass or polymer such as aluminum, polyamide or magnetic materials of high or low permeability, coercivity or magnetization and polished smoothness. Such a filling material is selected based on removable selectivity with respect to the basic hard material of the magnetic recording disc.

The present invention includes a storage disk, the storage disk having a substrate consisting of a top surface and a bottom surface, wherein the top and bottom surfaces are defined by raised surface portions and recessed surface portions, The raised surface portions of the surface portion and the bottom surface are arranged along the plane in parallel to each other, with the recessed surface disposed between the planes; At least one layered first material consisting of a top surface and a bottom surface, the bottom surface of the at least one layered first material being disposed on top of the raised surface portion and the recessed surface portion, at least The top surface of the first layered material is arranged to extend on top of the raised surface portion and the recessed surface portion; A layered second material consisting of a top surface and a bottom surface, the bottom surface of the layered second material being disposed on top of the top surface and the recessed surface portion of the at least one layered first material, An upper surface of the layered second material is disposed on top of the raised surface portion and the recessed surface portion; A layered third material consisting of a top surface and a bottom surface, the bottom surface of the layered third material being disposed over the top surface and the recessed surface portion of the layered second material, The top surface of the three materials is arranged at the level of the top surface of the layered second material. The layered third material consists of a metal material, a polymer material or a transparent material. In the present invention, the storage disk preferably comprises a top surface and a bottom layer surface, wherein the top surface and bottom layer surface are substantially flat throughout the entire surface. The first material constituting at least one layer may form a storage layer and a read layer. The first material constituting the at least one layer may include a magnetic material. The raised surface portion and the recessed surface portion may comprise a servo pattern. The storage disk includes a plurality of data tracks, wherein the raised shape includes mesas and channels, and the mesas or channels are disposed between the plurality of data tracks.

The present invention includes a disk drive, the disk drive having a disk substrate made up of a raised shape and a recessed shape, the raised shape forming the best level; And a filling material, the filling material being disposed in a recessed shape at a level substantially equal to the best level of the raised shape. The disk drive also includes a light source, where light follows an optical path between the disk substrate and the source based on the reflection of light from the substrate. The raised and recessed shapes form a servo pattern, where light is reflected from the servo pattern. The disk drive also includes a storage layer and a source of light, where light is guided along the optical path between the source and the disk substrate to heat the storage layer.

The present invention includes a storage disk, the storage disk including a disk substrate formed of a surface including a plurality of servo shapes, the servo shape having an area proportional to the radius of the disk substrate on which the servo shape is disposed.

A method of using a storage disk substrate that includes raised and recessed shapes; Defining the substrate to include raised and recessed shapes; Depositing a fill material over the etch stop surface to a sufficient depth such that the recessed shape is equal to or filled over the etch stop surface; Differentially removing the fill material such that the etch stop surface is not removed such that substantially no fill material remains on the etch stop surface and a substantially flat surface consisting of the fill material and the etch stop surface remains. .

The step further comprises depositing a sacrificial layer on the etch stop surface prior to depositing the fill material layer; The etching step here substantially etches the fill and sacrificial layer so that a substantially flat surface consisting of an etch stop surface and a fill material remains. The etch stop layer comprises silicon nitride and the sacrificial layer comprises silicon dioxide.

The present invention includes a storage disk, the storage disk having a disk substrate consisting of a surface having a raised shape and a recessed shape, the raised shape having the highest level; And disk substrate leveling means for leveling the recessed shape to a level substantially equal to the highest level of the raised shape.

Other features and advantages of the invention will be apparent to those skilled in the art in the following detailed description of the invention. The invention is not limited to the specific embodiments disclosed in this application or its equivalent, and may be used in a variety of ways, both known and unknown.

The present invention provides for increasing the storage capacity of a data disc drive while reducing the amount and complexity of optical path optics, electronic devices and / or associated read / write heads. The system uses the light transmitted by the optical element to servo track the data disc and to heat the data disc during writing and reading data, and uses inductive and magnetic elements for actual writing and reading.

Data storage discs include depressions and / or raised shapes, which shapes can be filled and / or polished with various materials. In this way, a smooth surface is provided for the write / read head that is maintained aerodynamically in flight conditions very close to the data disk surface. By providing a smooth surface, accumulation of contaminants is reduced or eliminated. The fill material may be formed reflectively to provide a large amplitude to the optical signal reflected from depressions and / or raised shapes. Light reflections from materials used to fill depressions and / or raised shapes can be used for sector identification and track tracking. Additionally, depressions and / or raised shapes may be formed to provide reflective areas that are proportional to the radius of the data disc on which they are located. As a result, the frequency content and / or amplitude change of the reflected optical signal can be minimized with respect to the radius of the data disc.

In the present invention, the data storage disk may further comprise a mesa disposed between the data tracks including the channel set or the data storage disk. Channels and / or mesas are applied to the data disc so that the shape of the data domain mark used to store the data along the data track is defined in the intersecting track direction and can be defined to more accurately match the desired square or square shape. It can be used to thermally channel and guide the thermal effects of light. Storage capacity and SNR consequently increase. The channels and / or mesas may be neutralized with the filling material.

The present invention is not limited to the specific and equivalent embodiments disclosed herein, and may be used in various ways, known or unknown.

Referring to FIG. 1, the basic elements of a data storage system implementing some of the present inventions are shown. 1 shows a storage system 100 comprising an actuator assembly 120, the actuator assembly being a plurality of radially spaced concentric circular data tracks on at least one rotating data storage disk 107. From there, the flying write / read head 106 for writing and reading data is moved.

2A, the disc of the present invention is shown in more detail. For the purpose of describing embodiments of the present invention, a specific data structure of the disc 107 has been disclosed.

The disk 107 is divided so as to be circumferentially around a plurality of uniformly and circumferentially spaced wedge-shaped servo sectors 212 extending continuously outward from the center.

Corresponding plurality of wedge shapes and spaced apart data sectors 216 are disposed so as to be adjacent to each other and around each other in each pair of servo sectors. Data sector 216 includes a number of data bits (marks) consisting of magnetic domains 281 used to store information on disk 107. The magnetic domain 281 marks are separated at regular intervals along the data track 103 at regular linear spaced intervals. The data track 103 is radially spaced radially with a very small constant radial data track pitch T _p . do.

1 to 4A, the data storage system of the present invention is described. 1 to 4A have been provided to illustrate the general structure of an exemplary storage system 100, which system includes data elements 216 as well as optical elements for reading servo sectors 212 and Optical, inductive and magnetic elements for writing and reading data therefrom.

As shown in FIG. 1, system 100 includes a set of flying heads 106 adapted for use with a set of disks 107 having dual sides. One flying head 106 is provided on each of each surface 107 of the disk. The head 106 is coupled to the rotating actuator magnet and coil assembly 120 by the suspension 130 and the actuator arm 105, whereby they are located on the surface of the disk 107. In operation, the disk 107 is rotated by the spindle motor to create an aerodynamic lift force between the flying head 106 and the rotating disk 107. Aerodynamic forces maintain each flying head 106 in flight conditions above the surface of each disk 107. The lifting force is opposed by the same and opposite spring force provided by the suspension 130. While not in operation, each flying head 106 is held on a ramp (not shown), generally spaced from the surface of the disk 107, without movement to storage conditions spaced from the surface of the disk 107.

The system 100 further includes a laser optical assembly 101, an optical switch 104, and an optical fiber set 102. Each optical fiber set 102 is coupled to an individual one of the set of flying heads 106 along a separate one of the actuator arm 105 set and the suspension 130.

The laser optical assembly 101 includes a diode laser source 131 of a type well known in the art. The laser optical assembly 101 guides the outward laser beam 191 from the laser source 131 to the optical switch 104. The laser optical assembly 101 receives the reflected laser beam 192 and processes the signal to output as a signal 149.

Referring to FIG. 3, a representative optical path of system 100 is shown in greater detail. In a preferred embodiment, the representative optical path is; One of the optical fiber set 102 and one of the flying head 106 set. The optical switch 104 provides sufficient selectivity to guide the outward laser beam 191 toward each end of each optical fiber 102. The outward laser beam 191 is directed by the optical fiber 102 to exit each end to pass through the flying head 106 and onto each disk 107.

The optical path described above is bidirectional in nature. Accordingly, the reflected laser beam 192 passes through the flying head 106 and is directed toward the end of the optical fiber 102. The reflected laser beam 192 propagates along the optical fiber 102 and is output at its near immediate end and optionally for continuous conversion into a signal representing the servo content mounted in the servo sector 212. Routed by optical switch 104 to transmit to optical assembly 101.

Referring to FIG. 2B, a particular servo sector is shown. In FIG. 2B, a particular servo sector 212 is shown enlarged. The following description briefly summarizes the reason for providing the outward laser beam 191 to selectively access the information constituting the servo sector 212. Servo sector 212 consists of encoded servo information including a coordinate reference system that allows access to data in data sector 216 of disk 107. In a preferred embodiment, the data tracks spanning each servo sector 212 comprise three types of encoded information; A servo timing mark (STM) 217, a data track address mark 232, and a fine ambient position error signal (PES) servo burst mark 252. As in the description below, the servo sector 212 may be embossed on the surface of the substrate 245 made of the disk 107 or otherwise formed of a recessed or raised shape. Embossing and / or molding discs is understood to provide fabrication and cost advantages. The type of material from which the disc is shaped has been demonstrated and described in several published documents known in the art.

In one embodiment, the servo information consists of a combination of raised and recessed shapes, with a representative recessed shape referred to as pit 215. In other embodiments it is understood that the functionality provided by the pit 215 may be provided by raised shapes. In addition, it is understood that the pit 215 can be constructed in other shapes, for example, circular or similar. In the preferred embodiment, the pit 215 is written along a predetermined one of the plurality of master tracks 210m, 210m + 1, 210m + 2 ..... The master tracks are arranged concentrically, centered, and separated equally spaced by the track pitch (T _p / 2), where the data tracks 103 consist of an optional one of a plurality of master tracks.

The servo timing mark is to the pit 215 of the first pattern written on any one of the master tracks 210m, 210m + 1, 210m + 2 ... to form a continuous radial line from the outer diameter to the inner diameter. Is done. The disk drive control system DDCS of the disk drive 100 may be configured to recognize the first pattern by marking the start of the servo sector 212 at every instant that the first pattern is monitored.

In a preferred embodiment, the data track address mark 232 consists of individual pits 215 of the second pattern. The second pattern is decoded by the DDCS and used as an address pointer for the recognition of the particular data track 103.

In the preferred embodiment, the position error mark 252 consists of individual pits 215 of the third pattern. The third pattern consists of four concentrically arranged segments 111, 212, 213, 214. The third pattern is used to maintain a position error signal for performing position adjustment of the write / read head 106 above a particular data track during track searching and track tracking well known in the art.

Each pit 215 has three dimensions controlled; It is characterized by the radial pit width erpw, the surrounding pit width ecpw and the pit depth epd. The control and uniformity and dimensions of the pit position set the basis for the DDCS to compensate for the diversity of user recorded data with an appropriate control algorithm.

The servo sector 212 of the present invention may or may not use an automatic gain control (AGC) field, and the AGC field may equivalently increase the data storage capacity of the data sector 216 or to minimize the size of the servo sector. Not used to make

In the prior art, diffraction information can be used to maintain head position on a particular data track of the disc. However, in a system using an optical fiber, the diffraction information may be undesirably degraded by the optical characteristics of the optical fiber. Instead, the present invention uses reflection information from the pit 215. The pit 215 deleteriously interferes with the reflected laser beam 192 such that the amplitude of the beam changes in proportion to the light reflected from the disk 107. The change in amplitude is carried on the reflected laser beam 192 and combined by known optical and electrical sensing techniques on the laser optical assembly 100 for output as a signal 149. The signal 149 is used as the position error signal PES for maintaining the position of the head 106 above the disk 107. Of course, in systems that do not use fiber optics, the diffraction information from the data disc is used for servo tracking and accordingly the invention is not limited to pit 215 but instead from other tracking features, such as channels, etc. It is understood that the use of diffraction information is made.

4A-4N, various views of the head of the present invention are shown. In FIGS. 4A-4G, the flying head 106 is shown for use on top of the recording / storage layer of one of the disk sets 107. Flying head 106; A slider body 444, an air bearing surface 447, a reflective substrate 400, and objective optics 446. The slider body 444 is dimensioned to accommodate the working distance between the objective lens 446, the optical fiber 102 and the reflective substrate 400. Reflective substrate 400 comprises a reflective surface, which surface is aligned such that laser beams 191, 192 are directed to and from disk 107 and for example for purposes of fine tracking. In one embodiment, the reflective substrate is registered in US Patent Application No. 08/08, which is incorporated herein by reference and registered as "Data Storage System with Enhanced Micro-machined Mirror," filed April 18,1997. And micro-machined mirrors as disclosed in 844,207. In a preferred embodiment, the reflective substrate 400 is shown by dotted lines representing the reflective center mirror portion on the side of the adjustable micro-machined mirror assembly opposite the visible portion in FIG. 4A (in one embodiment) A small adjustable reflective center mirror portion 420) of less than 300 μm. The small size and amount of micro-machined mirrors contribute to the ability to design flying heads with small amounts and low profiles. As used in the present invention, fine tracking and short search for a series of adjacent tracks allows the axis of rotation to be changed so that the propagation angles of the outward laser beam and the reflected laser beam can be varied before being transmitted to the objective lens 446. By rotating the centrally adjustable reflective center mirror portion 420. As the density of data tracks across the tracks increases, it is understood that the high bandwidth low amount of fine tracking means provided by the micro-machined mirrors is useful. Reflective center mirror portion 420, which is a low amount of high bandwidth mirror, is rotated by applying a differential voltage to a set of drive electrodes 404,405. The differential voltage on the electrode generates an electrostatic force that rotates the reflective center mirror portion 420 about the axial hinge set 410 to move the focused light spot 348 in the radial direction 450 of the disk. In one embodiment, approximately ± 2 degrees of rotation of the adjustable reflective center mirror portion 420 is focused to a spot of light 348 for storing and writing information, track tracking, and searching from one data track to another. It is used for the movement of. In other embodiments, other ranges of rotation of the adjustable reflective center mirror portion 420 are possible. Coarse tracking can be managed by adjusting the current to the rotating actuator magnet and coil assembly 120 (of FIG. 1). In the prior art, a large number of platter winchester disk drives in general use a separate set of suspension and actuator arms that move vertically in series as one integrated unit. Since each flying magnetic head of such an integrated unit is fixed relative to another flying magnetic head, it is not possible to track tracks on other magnetic disk surfaces simultaneously during track tracking for a particular magnetic disk surface. In contrast, in one embodiment of the invention, regardless of the movement of the set of actuator arms 105 and the set of suspension 130, the set of adjustable micro-machined mirror assemblies of the present invention may be used to operate independently. This allows for track tracking and searching for reading and / or writing information using one or more disk surfaces at any given time. Independent track estimation and search using a set of simultaneously adjustable micro-machined assemblies 400 preferably requires a separate set of individual fine tracking and mirror drive electronics.

Although the slider body 444 includes industry standard "mini", "nano" or "pico" sliders, alternatively dimensioned slider bodies 44 may be used.

The optical fiber 102 is coupled to the slider body 444 along the cutout portion 443 of the axis, and the objective lens 446 is coupled to the slider body 444 along the cutout portion 411 of the vertical edge. The cut out portions 443 and 411 may be designed as channels, V-grooves or any suitable alignment shape or means for coupling and aligning the optical fiber 102 and the objective lens 446 to the flying head 106. have. Laser beams 191 and 192; It traverses the optical path (to or from disk 107), which includes optical fiber 102, reflective substrate 400, and objective lens 446. The optical fiber 102 and the objective lens 446 are positioned to focus the outward laser beam 191 in the spot of interest, such as the focused light spot 348. The optical fiber 102 and the objective lens 446 are then secured in place using an ultraviolet curing epoxy or similar adhesive. Although the optical element consisting of the optical fiber 102, the objective lens 446 and the reflective substrate 400 is shown to be aligned along an optical path offset from the vertical center axis of the flying head 106, in other embodiments such an optical element is shown. It is understood that the optical elements may be aligned along some other optical path, for example along a vertical center axis as shown in FIG. 4G.

With reference to FIGS. 4H-4N, additional elements comprising the head of the present invention are shown as cross-sectional views of the top and side surfaces. In a preferred embodiment of the present invention, the flying head 106 further comprises a conductor element C, a shield element S1, a shield element S2 and a magnetic element; The magnetic element includes a permalloy pole piece P1, a permalloy pole piece P2, a magnetic resistance component MR and a pre / erase magnet 1064. In a preferred embodiment, the element MR is a type of magnetic resistive element which is formed to provide a sensitivity exceeding that of a typical magnetic resistive element and capable of reading a narrower data domain mark and thus a narrower data track pitch, For example, it consists of a giant magnetic resistance (GMR) element. GMR head technology is well known in the art and is described, for example by Robert White, in Transactions in IEEE Magnets, Vol. No5, published in September 1992, "Giant Magnetoresistance; Primer." Although the element MR in one embodiment uses GMR technology, it is understood that the invention is not limited to this embodiment, and that other types of elements, such as, for example, spin valve elements, fall within the scope of the invention. do.

In the preferred embodiment, the data is written by directing the magnetic flux formed by the conductor C using the magnetic pole pieces P1 and P2 and using the elements S1, MR and S2. In one embodiment, the element is 1 μm thick, suitably disposed to extend beyond the lateral temperature profile 279 formed in the write / store layer 355 by the spot 348 and the light spot 348 is a reflective substrate. Scanned back and forth by 400 has a width of 8 μm to allow reading and writing by the element.

In achieving narrow data track pitch reading, the present invention solves several problems. The first problem is that very high servo tracking error rejection should be implemented for data tracking when the data tracks are located in close proximity to each other; For example, a track pitch of 1 μm requires a crossover frequency of 2 kHz or more. In the present invention, this concern is solved by using the fine tracking capability of the micro-machined mirror, so that high speed fine tracking is improved to an extent that exceeds 10 times of the prior art, and this is achieved by the above-described reflective substrate. Described in the embodiment of 400.

Secondly, writing radial and peripheral position servo patterns (servo writing) requires accurate placement despite disk flutter and non-repeatable runout of spindle bearings. You can expect servo write accuracy for a 3.5-inch disk about 0.8 mm thick. In the present invention, this concern is described with reference to the description of the pit 215 described above, and the near perfect servo pattern can be achieved with an accuracy of almost 5 nm or less.

A third problem is that writing of data can cause side erase of the data track by about 0.3 [mu] m. Side erase is desirable for proper operation of the recording / reproducing process to erase old information. However, the side erase is scaled within the gap width of the write element, and the gap width is determined by the required magnetic data domain density, which is preferably as high as possible.

Finally, the head design presents a problem with tolerances. The photolithographic tolerance in manufacturing the magnetic head element is about 10 fractions of the element thickness. If the head element is 4 μm thick, the tolerance is about 0.4 μm.

At least two of the problems described above are addressed by the present invention as described below.

5A-5C, a diagram of the storage and reading of the present invention is shown. The following description summarizes how the outward laser beam 191 is used to selectively access information from the data track 103 consisting of the disk sector 216.

In a preferred embodiment, the disk 107 consists of a media type comprising at least two magnetic layers that interact, including a storage layer 202 and a read layer 204. Exemplary media consist of magnetto-static media or exchange coupled media. Storage layer 202 is made of a preferably high forcing material that supports the desired data bit density. The advantage of the high forcing storage layer is that it has the potential to overcome the highest superparamagnetic limits (ie propensity of adjacent domains to dissipate each other). The forcing is preferably high so that magnetic domain marks on the storage layer 202 cannot be written at temperatures below 65C. However, by forcing the storage layer 202 with the outward laser beam 191, the forcing of the storage layer 202 is preferably such that the bit is caused by the magnetic domains in the storage layer 202 by the elements P1, P2, c. Low enough to be able to be written to a storage location including data domain mark 281). In an embodiment where the storage layer 202 exhibits horizontal anisotropy (e.g., CoCr), the P1, P2, C elements (FIG. 5B) can orient the data domain mark 281 perpendicular to the planar direction. In an embodiment (eg, TbFeCo) in which the storage layer 202 is made of a material exhibiting vertical anisotropy (FIG. 5C), the data domain mark 281 may be oriented vertically from the planar direction.

In a preferred embodiment, the read layer 204 may be of a media type that exhibits a temperature dependency that is a function of magneto-crystalline anisotropy. However, layer 204 is sensitive to heating, and read layer 204 reacts in a different manner than storage layer 202.

In one embodiment, K, for example, incorporated herein by reference. As disclosed by Proc SPIE 1499.209 (1991) by Aratani et al., The read layer 204 is not read when the flux emitted from the data domain mark 281 in the underlying storage layer 202 is not heated. To be magnetized. In this embodiment, to read the data domain mark 281, the read layer 204 is heated by the outward laser beam 191 to a temperature lower than the temperature at which the storage layer 202 is heated for writing. In doing so, a temperature profile 279 is formed in the read layer 204 by the outward laser beam 191 as the disk 107 rotates. In this embodiment, a hole 580 is formed in the read layer 204 at a particular temperature along the temperature profile 279, through which the flux emitted from the data domain mark 281 below the hole 580 is topped. To align the regions of the magnetic domain in the read layer 204 of vertically and to allow the magnetic domain marks in the read layer 204 to be continuously detected by the head 106 elements S1, MR, S2. . The thermal temperature constant of the read layer 204 should preferably be long so that the heat generated by the light spot 348 does not disappear with time as the head elements MR, S1, S2 pass over the spot. In this embodiment, it is understood that the flux from the data domain mark 281 is only accessible during the time that the outward laser beam 191 is applied to form the aperture. Preferably, the hole is smaller than the diameter of the spot 348, so the outward laser beam 191 defines the read resolution in the intersecting data track 103 direction (radial direction) without limiting the resolution in the track direction.

In another embodiment, the medium 107 has an upper reading layer 204 of the flux from the data domain mark 281 in the underlying storage layer 202 when heated to a suitable temperature by the light spot 348. Acts in such a way as to align with the magnetic domain within, but unlike the embodiment described above, when power to the outward laser beam 191 is turned off, the magnetic domain is in the replica layer 204 in the aligned direction. A storage read layer 204 in which the magnetic domain is maintained. In this embodiment, the transfer / device magnet 1064 may be positioned on the trailing edge of the head for continuous reordering / erasing of the magnetic domains in the replica layer 204. In an exemplary embodiment, the transfer / element magnet 1064 is made of rare earth material to provide a magnetic field of sufficient strength for reordering / erasing. In other embodiments, the previous / element magnets 1064 may also be positioned on the leading edge of the head element or on top or away from the head. As the magnetic domain is oriented in the read layer 204 until it is erased, it will be appreciated that the thermal apertures 580 described above in this embodiment need not be rearranged for readout. The room temperature forcing of the read layer 204 is selected so that it does not affect the storage layer 202, but can be erased by the previous / device magnet 1064. In this alternative embodiment, since the magnetic domain of the read layer 204 remains aligned until it is erased, the manufacture of the head elements S1, MR, S2 is such that the element is close to the objective 446. It is easy because it does not require to be located.

In yet another embodiment, the medium 107 consists of a single layer of amorphous magnetic material that can be used. In this embodiment, a relatively thick (~ 100 nm) single layer of suitable rare earth-transfer material (RE-TM) is laser-assisted thermomagnetic writing by an element comprising the head 106. Can be prepared for both) and reading. The formation of the ferromagnetic RE-TM thin film is selected such that the compensation temperature is close to room temperature, providing a high forcing for stable storage of the medium 107 and a reduced forcing at elevated temperatures that allow writing. This same design has a residual magnetization near zero at room temperature and sufficient magnetization for selective reading of data tracks (with very adjacent track crosstalk) at a properly elevated temperature of the readout beam. Such media are published by Katayama et al in Paper 13-B-05 at MORIS-Magneto-Optical Recording International Symposium, January 10-13, 1999, in Monterey, California, which is incorporated herein by reference. -A new magnetic recording medium using a secondary read / write technique ".

In summary, the outward laser beam 191 and reflected laser beam 192 are used as part of an optical servo system for holding the flying head 106 centered on a particular data track. Unlike prior art optics, the outward laser beam 191 is used to heat the storage and readout layers 202, 204. When heated to a temperature lower than the write temperature, the read layer replicates the data domain mark 281 from the storage layer to the read layer 204 so that the flying head 106 can direct the direction of the magnetic domain in the hole 580. It can be detected. Although the area of the element constituting the head 106 is wider than the pitch of the data track 103, the temperature profile formed by the outward laser beam 101 is the edge of the written data domain mark 281 (in the intersecting track direction). Is preferably defined. Thus, it is possible to read the data domain mark 281 narrower than they can be written, thereby increasing the track storage density of the system 100.

In practice, however, the heat applied to the layers 202 and 204 by the outward laser beam 191 is the most significant of the head elements P1, P2, C, S1, MR, S2 during the transition time of the heated region. It is possible that there is a tendency to spread under the seat. The diffusion of heat is required so that the holes 580 can be formed extending far enough below the head elements P1, P2, C, S1, MR, S2 for writing and reading. However, due to thermal diffusion, the thermal gradient forming the hole is not steep, and thus the edge of the data domain mark 281 is not well controlled or defined. For data reading by the head elements S1, MR, S2, the data domain mark 281 should preferably consist of a straight edge and not overlap between the data tracks 103.

In general, the layers 202 and 204 have different rates of heat diffusion in the vertical (axial) and horizontal (planar) directions.

To understand the horizontal diffusion heating process, heating the surface of the disk 107 with the outward laser beam 191 is similar to the ratio of the flow of viscous fluid on a flat moving surface, where the height of the fluid above the surface corresponds to temperature. do. From this similarity it can be seen that the fluid spreads in all directions so that the inclined flexure of the lateral temperature profile of constant height looks like an expanding tear. An exemplary lateral temperature profile 279 formed by the outward laser beam 191 is shown in FIG. 4H.

In order to understand the temperature profile shown in FIG. 5A of the vertical diffusion process, disk 107 is similar to a screen through which a fluid can flow. Vertical flow makes the gradient more steep. When the vertical flow is high, adjacent data tracks 103 on disk 107 show small rows, which are similar to the height of the fluid. Thus, if it is possible to adjust the spreading ratio perpendicular to the lateral direction, adjacent data tracks 103 can be overwritten and irregularly shaped data domain marks 281 can be formed. Therefore, the formation of the data domain mark 281 can be controlled for proper reading by the elements S1, MR, and S2.

The present invention provides a channel or mesa 266 between the data tracks 103 of the disc 107, thereby blocking and / or guiding thermal conduction between the data tracks of the disc 107, thereby avoiding the aforementioned undesirable vertical and It is possible to reduce and / or control the effects of horizontal heat spreading, thus demonstrating improved writing and reading by the head 106 elements. The use of channels or mesas 266 is described below, with a detailed description of the pit 215 taking precedence.

With reference to FIGS. 6A-6D, the steps for producing raised and recessed shapes and the continuous transfer of the shapes to the substrate of the disk 107 are shown. Said step; Using conventional injection molding techniques for forming plastic substrates of materials such as polycarbonate or alternative techniques such as embossing of relatively thin polymer layers on a substrate of polished glass or aluminum. Alternatively, the shapes may be applied to ion milling, which involves applying a photosensitive mask layer, such as glass or aluminum, to the substrate, defining a photolithographically desired area and photosensitive layer, and involving reactive ion etching or removal of the photosensitive layer. By etching the substrate. Another alternative is to apply a photosensitive layer of desired thickness to the substrate material and define pits directly within the photosensitive layer by photolithographic steps. Other methods for defining a pit pattern in a substrate of another type of drive, including magnetic optics, optics, or magnets, may be defined, are already defined, and do not form part or limit of the present invention.

For all the techniques described above and other similar techniques except for differential etching to a glass substrate, the shape is generally relatively soft of equivalents, such as in embodiments using plastic or aluminum or, for example, the pit 215. Can be defined within the substrate. For subsequent differential removal steps, one example to be described is chemical mechanical polishing (CMP), in order to define as close as possible, a relatively hard abrasive resistance layer is required on top of the substrate and the finished relief of the disc Ready

For example, in the disk 107 of the present invention of Figs. 6A to 6D, a continuous layer for controlling the thermal, magnetic and optical performance of the recording layer can be used. Such layers in a general first surface design include: a low thermal diffusion layer 610, such as, for example, aluminum; Bottom dielectric material layer 612, storage layer 202; Read layer 204; And an upper dielectric layer 620. In an exemplary embodiment, the thickness of each such layer is about 50 nm. As will be described, dielectric layer 620 is both relatively abrasive resistant and thus may serve as a potentially hard layer for differential removal treatments, and / or sputtered silicon dioxide layer 618. The cross section after this step is shown in Figure 6b. Once again, this is an exemplary continuous layer, and it should be noted that the present invention is not limited to the use of such continuous layer but can be easily applied for use with other magnetic-optical, optical or magnetic recording discs. For example, in embodiments where the substrate is relatively soft, a silicon nitride layer (not shown) may be used between the substrate 245 and the thermal diffusion layer 610.

In conventional embossing processes for optical data storage disks, the depth of each pit is generally about 1/4 wavelength of red or about 160 nm deep, for example. Accordingly, when a general pit is used, a change in the pit depth tolerance causes a change in the detected reflected signal. In contrast, in the present invention, the signal 149 (of FIG. 1) derived from the pit 215 is a function of the reflectance of the fill material rather than the relatively tight tolerances required for the pit depth of the prior art.

In a preferred embodiment, both silicon dioxide layer 618 and silicon nitride layer 699 are used. The silicon dioxide layer is used as a sacrificial layer to ensure that the correct layer thickness is maintained even after finishing the chemical polishing or other etching process described below. In a preferred embodiment, fill material 630 is deposited or otherwise placed on top of layers 610, 612, 202, 204, 618, 699. For example, one fill material 630 may be sputtered aluminum or an aluminum alloy. An exemplary thickness is about twice the depth of each pit 215, for example about 300 nm, for a pit depth of about 160 nm. A cross-sectional view of a substrate 245 with deposited fill material 630 is shown in FIG. 6C. In the next step, the disk 107 is subjected to a differential removal process that removes the fill material 630 but terminates or stops in the hard silicon dioxide layer 618. A useful treatment is polishing using a CMP treatment developed for IC fabrication, such as that disclosed in the paper in "Chemical Mechanical Polishing of Dual Damascus Aluminum Interconnect Structures" by Wang et al., 1/95. This treatment uses commercially available devices and materials to provide a polishing selectivity of about 100 between the fill material and the silicon dioxide layer 618. Thus, in certain embodiments, less than 2 nm of sacrificial silicon dioxide layer 618 is preferably removed when polishing all 300 nm of fill material and using 50% excessive polishing. The resulting surface is substantially flat with the fill material filling the pit 215. Silicon dioxide layer 618 is then etched using a chemical wet etchant, which preferably does not properly etch underlying nitride layer 699.

Preferably, after this last step, the surface of the disk 107 as shown in FIG. 6D is approximately equal to the thickness of the layer 620 or in a maximum height variation of 10 times less than the prior art in an exemplary embodiment ( should have disturbance). Thus, unlike the prior art, the disc 107 of the present invention provides the flying head 106 with an unchanged surface, which allows the head to fly stably or to have a reduced flight height. Those skilled in the art will appreciate that the flying head 106 of the present invention is useful, as well as for optical systems of similar data storage applications. Since the pit 215 is filled with reflective material, the reflected signal 192 has an increased amplitude that exceeds the signal of the prior art diffraction servo tracking method, for example three times more in one embodiment. In addition, the pit 215 of the present invention does not provide a cavity subject to a source of contamination from a source, such as a disk lubricant, for example, the disk 107 itself, and the deposition of that particular material over time. Deteriorates signal 149.

As a further improvement, if a small reduction in the silicon nitride layer 699 thickness is allowed, no sacrificial dioxide layer 618 is required, and the top surface becomes flatter and smoother.

Referring to FIG. 7A, a signal derived from a pit having a constant radius is shown. As described above, the servo sector 212 of the present invention may or may not use an automatic gain control field (AGC). If the AGC field is not used and the pit has a constant magnitude with respect to the radius of the disc, the signal derived from the pit may change due to the slow speed of the inner radius relative to the outer radius of the disc. 7A shows representative unfilled pits and representative servo signals derived therefrom at both the outer and inner radii of the disk. The pulse widths of the signals change, and their characteristics affect the exact positioning of the head on the top of the disk.

Referring to FIG. 7B, a signal derived from a pit having a non-constant radius is shown. In a preferred embodiment, the pit 215 consists of an area made up of an area, for example a reflective surface area or radius, such that the area is proportional to the radius of the disk 107 on which the pit 215 is disposed. Thus, the signal 149 derived from the pit 215 of FIG. 7B has a similar pulse width independent of the position of the pit 215 on the disk 107. As a result, the change in the servo signal 149 resulting from the pulse from the pit 215 can be minimized. Thus, in an embodiment of a system 100 that uses a digital servo channel in which pulses are sampled and integrated, the pulse width obtained from the outer radius can preferably be formed equal to the wide pulse width obtained from the inner radius of the disk 107. Because of this, a reduced sampling rate can be used. It is also understood that pits consisting of an area proportional to the radius of the disk 107 in which the pits are placed may find utility in embodiments not filled with a filling material, such as in a drive using diffraction rather than reflection from the pits.

Referring to FIG. 8A, a cross section of a substrate having a raised and recessed shape is shown. 8A shows that a process for filling the pit 215 may be used to fill the channel 266. Thus, some of the same advantages obtained from filling the pit 215 with the filling material 630, for example, a source of contamination as well as the advantage of providing a flat surface to hold the flying head 106 above the disk 107. The advantage of providing a reduction in accumulation may also apply to the filling of channel 266.

Filled channels or mesas 266 between the data tracks 103 of the disc 107 provide additional advantages to the present invention. This is because a highly conductive and high heat capacity fill material such as aluminum or metal in the channel 266 between the data tracks 103 behaves like a heat sink, while the low conductivity low heat capacity fill material described below It can be seen by the additional similarity that it acts as a vertical wall between the data tracks 103 to block radial heat flow.

At the same time, it is shown that high conductive fill material 630, such as aluminum, diffuses the heat generated by the spot 348, which in turn causes the data domain mark 681 to be in their preferred tetragonal or square shape during the writing of the mark. It shows that it loses. On the one hand, the low conductivity fill material causes the edges of the data domain marks to be more straight and thus approximately perpendicular to the channel 266 to stop in the channel. As a result, aluminum may not be the best choice for the fill material 630.

In one embodiment, channels 266 between data tracks 103 have a relatively narrow width of 5 to 1 or more aspect ratios, which define the vertical dimension of channel 266 between 100 and 1000 nm. Certain known types of fill materials that become reflective materials when deposited as thin layers and support the dimensions and aspect ratios above include metals (ie, aluminum described above) and certain types of dye polymers. However, as mentioned above, the metal improperly acts as a heat sink. Dye polymers exhibit low conductivity and thus can be used as filling materials but they are difficult to polish. Glass is another material that can be used because of its low conductivity, and glass can be used in embodiments where increased reflectivity is not preferred, such as an optical drive using diffraction information for servo tracking.

Referring to FIGS. 8B-8E, simulations of heat diffusion resulting from applying the outward laser beam to a medium having no channel and a medium having a channel are shown. As mentioned above, applying a beam of light onto a medium of the prior art results in a temperature profile that inappropriately affects the formation of data domain mark 281. 8B and 8C show the temperature profile of a particular hole formed in the prior art, while FIGS. 8D and 8E show the temperature profile formed using the disk 107 with the channel 266. As shown in the individual temperature profiles at the top of FIG. 8F, the temperature gradient is steeper on the disc with the channel 266 of the present invention. As a result, the data domain mark 281 is well defined and formed in the track and cross track directions. In addition, the channel 266 of the present invention serves to guide and control the thermal diffusion such that the data domain mark 281 shows the desired rectangular or square shape, thereby increasing the flux density during data reading. It can be seen that the head 106 (S1, MR, S2) is provided to the element. By confining the data domain mark 281 in the intersecting track direction, uniform background noise to the head element MR can be minimized during wide writing and narrow reading, which allows higher storage data density compared to the prior art.

With reference to FIGS. 9A-9E, disks including mesas and raised shapes are shown. 9A-9E illustrate another method for channeling the heat generated by light spot 348, whereby data track 103 is disposed between mesas 266 rather than between channels. In this embodiment, the mesa 266 is formed of the same material as the substrate 245, for example glass. In the manufacture of mesa 266, the process may include a negative resist for reverse mastering the disk format to include the formation of the mesa 266 as well as the servo sector 212 pattern. In this embodiment, it is understood that the servo sector 212 pattern includes a raised shape 215 rather than a pit.

In view of the above, the disk 107 is executed in the following order; A layer of material deposited in the order of aluminum, bottom dielectric layer, storage layer, read layer, top dielectric layer. Accordingly, an exemplary manufacturing process of disk 107 including mesa 266 may include; Mastering the glass substrate such that the mesa 266 and the servo pattern have a shape depth of 50-100 nm, depositing an aluminum or permalloy (nickel and iron) layer 610 on the substrate 245 and as an etch stop layer Chemical mechanical polishing of the aluminum or permalloy using a glass substrate, depositing a dielectric layer, depositing a storage layer 202 and readout layer 204, and depositing a passivation layer of silicon nitride 699 Steps.

Mesa 266 preferably serves to interfere with the thermal conduction of the thermally conductive aluminum layer 610 in the radial direction. Since the recording layers 202 and 204 are relatively thin and have a thermal conductivity of less than about 20% compared to the layers below, they are thermally bonded with the aluminum layer 610. Thus, although they exhibit some radial thermal conductivity with respect to the recording layers 202 and 204, there is a thermal conductivity discontinuity at the edge of the mesa 266 between the tracks, providing a good thermal barrier.

It is expected that about 50% of the outward laser beam 191 passes through the recording layers 202 and 204. The outward laser beam 191 is reflected by aluminum or absorbed by the substrate 245 at the center of the disk 103. Generally about 20% of incident light is reflected at the center of track 103 and only about 10% of incident light is reflected at mesa 266. Thus, depending on the requirements, a tradeoff between servo signals for incident light absorption may be required. It is understood that this difference in reflection can be used for servo tracking in embodiments that use diffraction information.

With reference to FIGS. 9B-9E, representations of temperature profiles in disks with mesas and disks without any mesas are shown. 9C-9E show 60, 90 and after the outward laser beam 191 is applied as a 3 ns 1 mW focused spot 348 with full width half height maximum (FWHM) = 550 at the center of the track 103. An example temperature profile distribution in the disk 107 for three snap spots of 150 ns is shown. The depth of the medium 107 is the Y direction and the radial direction of the disk is the X direction. The left edge of the plot is a half track point of 350 nm. The disk 107 thin film structure is 85 nm silicon nitride, 20 nm storage and readout layer, 55 nm aluminum on a polycarbonate substrate. Mesa 266 expansion of the substrate extends to the bottom of the storage and readout charges, destroying the aluminum layer. The mesa is about 80 nm wide, which is concentrated about 20% from the right edge of FIGS. 9C-9E.

9E shows the vertical temperature profile distribution in a disk with no channel and a channel with 60 ns after the outward laser beam is applied. The thermal gradient within the disc is very low. It should be noted that the temperature and the stepped temperature of FIG. 9D are one third of that of FIG. 9A. This shows that for a disk containing mesa 26, the temperature profile distribution in the storage and reading layers is very uniform at the center of the track 103 and the thermal gradient is steep at the edge of the track.

In an exemplary embodiment where continuous power is applied to generate heat, heat is propagated at a wavelength between mesas 266 and spot 348 beneath the head 106 read / write element as required. After passing, heat remains between mesas 266 at 4 microns or 1 microsecond.

Although the present invention has been described with reference to the preferred embodiments, it is understood by those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (18)

A storage disk, A substrate consisting of a top surface and a bottom surface, the top surface and the bottom surface being defined by a raised surface portion and a recessed surface portion, wherein the raised surface portion and the raised portion of the bottom surface are Arranged along planes in parallel to each other, the recessed surface portions being disposed between the planes; At least one layered first material consisting of a top surface and a bottom surface, wherein the bottom surface of the at least one layered first material is a top of the raised surface portion and a top of the recessed surface portion And the upper surface of the at least one layered first material extends above the raised surface portion and above the recessed surface portion; A layered second material consisting of a top surface and a bottom surface, the bottom surface of the layered second material being the top and the recessed surface of the top surface of the at least one layered first material Disposed on top of the portion, wherein the upper surface of the layered second material is disposed on top of the raised surface portion and on top of the recessed surface portion; And A layered third material consisting of a top surface and a bottom surface, wherein the bottom surface of the layered third material is the top of the top surface and the top of the recessed surface portion of the layered second material And the top surface of the layered third material is disposed at the same level as the top surface of the layered second material. The method of claim 1, wherein the layered third material comprises: A storage disk, characterized in that it is selected from the group consisting of metallic materials, polymeric materials and transparent materials. 2. The storage disk of claim 1, wherein the storage disk comprises a top surface and a bottom layer surface, wherein the top surface and the bottom layer surface are flat with respect to the top and bottom layer surfaces. The storage disk of claim 1, wherein the at least one first layer of material comprises a storage layer and a read layer. 2. The storage disc of claim 1, wherein the at least one layered first material is made of a magnetic material. 2. The storage disk of claim 1, wherein the raised surface portion and the recessed surface portion are made of a servo pattern. 2. The storage disk of claim 1, comprising a plurality of data tracks, said raised shape comprising mesas and said mesas disposed between said plurality of data tracks. 2. The storage disc of claim 1, comprising a plurality of data tracks, said raised shape comprising a channel and said channel disposed between said plurality of data tracks. A storage disk, A disk substrate comprising a surface consisting of a raised shape and a recessed shape, the raised shape being at the highest level; And a filling material disposed in said recessed shape at the same level as said highest level of said raised shape. 10. The storage disk of claim 9, further comprising a light source, the light source being oriented along an optical path between the source and the disk substrate based on the reflection of light from the disk substrate. 11. The storage disk of claim 10, wherein the shapes are in a servo pattern and the light is reflected from the servo pattern. 10. The device of claim 9, further comprising a storage layer and a light source disposed on top of the surface, wherein the light is directed along an optical path between the source and the disk substrate to heat the storage layer. Storage disk. A storage disk, And a surface formed of a plurality of servo shapes, wherein the servo shape comprises an area proportional to the radius of the disk substrate on which the servo shape is disposed. In a method of using a storage disk substrate consisting of a raised shape and a recessed shape, Defining the substrate to constitute raised and recessed shapes; Depositing a fill material over the etch stop surface to a depth sufficient such that the recessed shape exceeds or fills the etch stop surface; And Differentially removing the fill material such that the fill material on top of the etch stop surface is removed without or slightly removed, leaving a flat surface consisting of the fill material and the etch stop surface. Characterized in that. 15. The method of claim 14, further comprising depositing a sacrificial layer on top of the etch stop surface prior to depositing the fill material, wherein the differential removal step comprises etching the fill material and the sacrificial material to etch the etched material. Leaving a stationary surface and a flat surface made of the filler material. 16. The method of claim 15, wherein said etch stop layer is comprised of silicon nitride and said sacrificial layer is comprised of silicon dioxide. The method of claim 15, wherein the filling material; And a metal material, a polymer material and a transparent material. A storage disk, A disk substrate made of a surface, wherein the disk substrate is made up of a raised shape and a recessed shape, the raised shape being at the highest level; Disk substrate leveling means for leveling the recessed shape to the same level as the highest level of the raised shape.