JP2011192354A - Method and apparatus for drawing electron beam, mold manufacturing method, and magnetic disk medium manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To draw a fine pattern such a hard disk pattern on an entire substrate surface with high accuracy in a short time by simple control. <P>SOLUTION: In drawing an electron beam EB by drawing-on/off control depending on the rotation of a substrate while rotating a resist-coated substrate 10 in one direction, the electron beam is deflected in the substrate rotation direction and the radial direction to be moved to the drawing start position of a second section, after drawing on a first section of an element divided into n parts in the radial direction. The drawing operation is performed on the element m times (m≥2) per rotation, and the subsequent elements are sequentially drawn thereafter. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention provides an imprint mold for a high-density magnetic recording medium such as a discrete track medium or a bit pattern medium, a master carrier for magnetic transfer, and the like for drawing a fine pattern corresponding to a desired concavo-convex pattern. The present invention relates to an electron beam drawing method and an electron beam drawing apparatus.

  The present invention also relates to a method for producing an imprint mold having a concavo-convex pattern surface or a mold including a master carrier for magnetic transfer, which is produced through a step of performing drawing using the electron beam drawing method. The present invention relates to a method for manufacturing a magnetic disk medium in which a concavo-convex pattern is transferred using a print mold, and a method for manufacturing a magnetic disk medium in which a magnetic pattern is transferred using a magnetic transfer master carrier.

  In current magnetic disk media, information patterns such as servo patterns are generally formed. In addition, due to the demand for higher recording density, adjacent data tracks are separated by groove patterns consisting of grooves, reducing magnetic interference of recorded data signals between adjacent tracks, and reducing recording density. Discrete track media (DTM) that have been enhanced are attracting attention. In the bit pattern media (BPM) proposed for higher density, the magnetic material (single domain fine particles) in which the data track constitutes a single magnetic domain is physically isolated and arranged in a regular dot pattern. Thus, it is a medium for recording 1 bit per particle.

  Conventionally, a fine pattern such as the servo pattern is formed on a magnetic disk medium by a concave-convex pattern or a magnetized pattern, and a predetermined fine pattern is formed on a master disk of a magnetic transfer master carrier for manufacturing a high-density magnetic disk medium. An electron beam writing method for patterning the substrate has been proposed. This electron beam drawing method performs pattern drawing by irradiating an electron beam corresponding to a pattern shape while rotating a substrate coated with a resist (see, for example, Patent Document 1 and Patent Document 2).

  In the beam irradiation method of Patent Document 1, for example, when drawing a rectangular or parallelogram element extending in the track width direction constituting a servo pattern, the electron beam is deflected in the radial direction while being vibrated at high speed in the circumferential direction. In this method, the element is scanned and painted to fill it.

  In addition, the electron beam drawing method of Patent Document 2 is directed to drawing an electron beam in the radial direction along with the rotation of the substrate when drawing elements of recording bit strings having a constant length in the track width direction and different lengths in the track direction. In this method, the image is drawn with high-speed vibration while adjusting the amplitude.

  Further, as an on / off drawing method, an electron beam is irradiated on / off in accordance with the pattern shape while rotating a substrate coated with a resist, and the substrate or the electron beam irradiation device has a radius of one beam width per rotation. A method of drawing a pattern by moving in a direction is also known.

JP 2004-158287 A JP 2006-184924 A

  However, since the electron beam drawing methods of Patent Document 1 and Patent Document 2 described above can draw, for example, one track element by one rotation of the substrate, high-speed drawing of the entire substrate is possible, but the beam is vibrated at high speed. However, it is necessary to control the deflection in the radial direction or circumferential direction of the substrate, and signals for controlling the electron beam irradiation apparatus such as beam irradiation and scanning such as amplitude control and triangular wave control become very complicated. There is a problem that it takes a lot of time to change the program when changing the program.

  On the other hand, the above on / off drawing method can basically perform drawing by time control for turning on / off the beam irradiation according to the drawing pattern with respect to the rotation of the substrate, and the signal for controlling the electron beam irradiation apparatus is Although relatively simple, the rotation speed of the substrate is limited, and only one beam width can be drawn per rotation, the drawing area is small, and the drawing time of the entire substrate is long. The speed of the substrate can be increased by increasing the rotation speed of the substrate, but the error of the drawing position due to the error of the control accuracy of the drawing on / off control becomes large, and the accuracy of the pattern shape to be miniaturized and the drawing position can be ensured. Has a difficult problem.

  As described above, the on / off drawing has simple control of the drawing apparatus.For example, it has an advantage that it can easily cope with the change of the drawing pattern, but the problem is that the drawing time becomes longer as the drawing pattern becomes finer. It has become.

  In view of the above circumstances, the present invention provides an electron beam writing method and an electron beam drawing method capable of drawing a fine pattern such as a hard disk pattern in a predetermined element shape on the entire surface of the substrate with high accuracy and in a short time by simple control. An object of the present invention is to provide an electron beam drawing apparatus for performing beam drawing.

  The present invention also provides a method for producing a mold, such as an imprint mold or a magnetic transfer master carrier, having a fine pattern drawn with high precision by an electron beam, and a concave / convex pattern or magnetic pattern using the mold. It is an object of the present invention to provide a method for manufacturing a magnetic disk medium to which a pattern is transferred.

The electron beam drawing method of the present invention scans an electron beam with an electron beam drawing apparatus while rotating the rotary stage on a substrate coated with a resist and placed on the rotary stage, and based on the irradiation diameter of the electron beam. In an electron beam drawing method for drawing a fine pattern composed of large elements,
While rotating the substrate in one direction, with respect to the rotation of the substrate, an electron beam is emitted by a drawing-on signal at a predetermined rotation position of the substrate corresponding to the drawing start position of the element to be drawn based on the drawing data of the fine pattern. The first partition portion of the element divided into n in the radial direction is drawn by drawing on / off control in which fixed irradiation is performed, drawing is performed in the rotation direction depending on the rotation of the substrate, and drawing is stopped by a drawing off signal. In order to draw the second section of the element, the electron beam is returned to the drawing start position of the element by deflection in the same direction as the rotation direction of the substrate. Alternatively, after the substrate is moved in the radial direction of the substrate and the drawing by the drawing on / off control is performed m times (m ≧ 2) for the element, the next element is drawn. Proceeds to, characterized by sequentially rendering the m partitions fraction of the n divided elements during one revolution of the substrate.

  In the drawing method, the rotation speed of the rotary stage is controlled so that the linear velocity is constant so that the rotation speed of the rotation stage is inversely proportional to the radius of the drawing position and is fast in the inner track drawing and slow in the outer track drawing. The drawing control signal is generated based on a drawing clock signal generated in association with the rotation of the rotary stage, and the drawing clock signal indicates the number of clocks in one rotation of the rotary stage and the radius of the drawing position. Regardless of this, it is preferable to use a constant value for each track.

  The “element” usually has a size corresponding to one track of the hard disk, and the larger the “number of divisions n”, the higher the accuracy of drawing, but the drawing time is proportional to the number of divisions n. In order to increase the length, about n ≦ 16 is selected, and more preferably n ≦ 8.

  On the other hand, the “repetition number m” per one rotation can be shortened as the number of repetitions is 2 or larger, but the upper limit is determined uniquely from the rotational speed of the rotary stage and the deflection speed of the beam deflecting means.

  In order to realize the above-described electron beam drawing method, the electron beam drawing apparatus of the present invention rotates a substrate on which a resist is applied, and sets the number of rotations of the rotation stage in accordance with the radius of the drawing position. A drive control unit that maintains a constant speed, a drawing on / off unit by a blanking unit that blocks irradiation of an electron beam emitted from an electron gun, and beam deflection that scans the electron beam in a rotational direction and a radial direction. And a formatter for outputting an on / off signal for the drawing on / off means and a deflection signal for the beam deflection means based on a drawing data signal.

  The mold manufacturing method of the present invention is manufactured through a step of drawing a desired fine pattern on the resist-coated substrate by the electron beam drawing method, and forming a concavo-convex pattern corresponding to the desired fine pattern. It is characterized by this. Here, the mold is a carrier having a desired concavo-convex pattern shape on the surface, an imprint mold for transferring the concavo-convex pattern shape to the magnetic disk medium, and a magnetic pattern corresponding to the concavo-convex pattern shape on the magnetic disk. For example, a master carrier for magnetic transfer for transferring to a medium.

  The method for producing a magnetic disk medium of the present invention includes a step of drawing a desired fine pattern on a substrate coated with a resist by the above-mentioned electron beam drawing method, and forming an uneven pattern corresponding to the desired fine pattern. Using the produced imprint mold, a concavo-convex pattern corresponding to the concavo-convex pattern provided on the surface of the mold is transferred.

  In another method of manufacturing a magnetic disk medium according to the present invention, a desired fine pattern is drawn on the resist-coated substrate by the electron beam drawing method, and a concavo-convex pattern corresponding to the desired fine pattern is formed. A magnetic transfer master carrier produced through the above steps is used, and a magnetic pattern corresponding to the concavo-convex pattern provided on the surface of the master carrier is magnetically transferred.

  According to the electron beam drawing method of the present invention, an electron beam is scanned by an electron beam drawing apparatus while rotating a rotary stage on a substrate coated with a resist and placed on the rotary stage, and the irradiation diameter of the electron beam is measured. For drawing a fine pattern composed of larger elements, while rotating the substrate in one direction, the substrate corresponding to the drawing start position of the element to be drawn is based on the drawing data of the fine pattern with respect to the rotation of the substrate. An element that is fixedly irradiated with an electron beam at a predetermined rotation position by a drawing on signal, draws in the rotation direction depending on the rotation of the substrate, and is divided into n in the radial direction by drawing on / off control that stops drawing by a drawing off signal In order to draw the second section of the element, the electron beam is rotated in the direction of rotation of the substrate. The element is returned to the drawing start position of the element by deflection in the same direction as the above, and at the same time, the electron beam or the substrate is moved in the radial direction of the substrate, and the drawing by the drawing on / off control is performed m times (m ≧ m) 2) After the process, the process proceeds to the drawing of the next element, and by sequentially drawing m sections of the n-divided elements during one rotation of the substrate, the element is moved by amplifying the electron beam at high speed. Triangular wave control and the like are not required compared to the drawing method that draws as if it is filled in, the control for the drawing is easy, and even if there is a change in the fine pattern, the change can be easily handled, and simple Compared to on / off drawing, which draws for one beam width in one rotation, a plurality of sections are drawn during one rotation, so that no exposure time during which no beam is irradiated during the rotation time. Reduced to enables high-speed rendering of m times, without complicating the control signal of the electron beam irradiation device so, drawing time to increase the drawing efficiency can be greatly shortened.

  Moreover, dose management is dependent on the rotation speed of the substrate during exposure, and it is easy to obtain a uniform dose in drawing of the inner and outer peripheries, and the drawing accuracy is improved by drawing the uniform dose. It is possible to perform high-speed drawing at a low speed without increasing the rotation speed, and it is possible to achieve both high-precision element arrangement and high-speed drawing. As a result, a fine pattern as designed can be drawn on the entire surface of the substrate with high accuracy at high speed, and the drawing time can be shortened by improving the drawing efficiency.

  At that time, the rotation speed of the rotation stage is controlled so that the linear velocity is constant so that the rotation speed of the rotation stage is inversely proportional to the radius of the drawing position and is fast in the inner track drawing and slow in the outer track drawing. Is generated based on the drawing clock signal generated in conjunction with the rotation of the rotary stage. The drawing clock signal is used to determine the number of clocks in one rotation of the rotary stage at each track regardless of the radius of the drawing position. If the value is constant, the dose amount can be equalized between the inner drawing and the outer drawing, and the control according to the radial position can be easily performed with high accuracy. In other words, it is possible to draw the fine pattern on the inner track and the outer track on the same track with the same irradiation dose, and the same signal element can be drawn with the same number of clocks. Since the control according to the above can be easily performed with high accuracy, a fine pattern can be drawn on the entire surface of the substrate with high accuracy at high speed, and the drawing time can be shortened by improving the drawing efficiency.

  On the other hand, in order to realize the electron beam drawing method, the electron beam drawing apparatus of the present invention rotates a substrate on which a resist is applied, and the number of rotations of the rotation stage in accordance with the radius of the drawing position. Drive control unit for maintaining a constant speed, drawing on / off unit by blanking unit for blocking irradiation of electron beam emitted from electron gun, beam deflection unit for deflecting and scanning electron beam in rotation direction and radial direction And a formatter that outputs an on / off signal for the drawing on / off means and a deflection signal for the beam deflecting means based on the drawing data signal, so that a desired fine pattern can be drawn at high speed and with high precision. The drawing time can be shortened by improving the above.

  Furthermore, according to the mold manufacturing method of the present invention, a step of drawing a desired fine pattern on the resist-coated substrate by the above-described electron beam drawing method, and forming an uneven pattern corresponding to the desired fine pattern. Thus, a carrier having a highly accurate uneven pattern shape on the surface can be easily obtained.

  Further, according to the method for manufacturing a magnetic disk medium of the present invention, a desired fine pattern is drawn on the resist-coated substrate by the electron beam drawing method, and a concavo-convex pattern corresponding to the desired fine pattern is formed. In the case of this imprint mold, an imprint technique is obtained by using an imprint mold manufactured through a process to transfer and producing a concavo-convex pattern corresponding to the concavo-convex pattern provided on the surface of the mold. Discrete track media with excellent characteristics by transferring the shape to the surface of the media at once by pressing the mold against the surface of the resin layer that is used as a mask in the process of forming the magnetic disc media. And magnetic disk media such as bit pattern media can be easily created.

  In addition, according to another method of manufacturing a magnetic disk medium of the present invention, a desired fine pattern is drawn on a resist-coated substrate by the above-described electron beam drawing method, and an uneven pattern corresponding to the desired fine pattern is obtained. This magnetic transfer master carrier is produced by magnetically transferring a magnetic pattern corresponding to the concavo-convex pattern provided on the surface of the master carrier using the magnetic transfer master carrier produced through the step of forming In this case, since the fine pattern of the magnetic layer is formed on the surface, the master carrier is superimposed on the magnetic disk medium, and a magnetic field is applied using a magnetic transfer technique, thereby forming a fine pattern of the magnetic layer on the magnetic disk medium. A corresponding magnetic pattern can be transferred and formed to easily produce a magnetic disk medium with excellent characteristics.

It is a top view which shows the example of the fine pattern drawn on a board | substrate with the electron beam drawing method of this invention. FIG. 4 is a partially enlarged view of a fine pattern of a discrete track medium. It is a characteristic view which shows the relationship between a drawing radius position and a board | substrate rotation speed. It is a schematic block diagram of the electron beam drawing apparatus of one Embodiment which implements the electron beam drawing method of this invention. FIG. 4 is an enlarged schematic diagram (A) showing an example of a basic drawing method of elements constituting a fine pattern and various control signals (B) to (F) such as deflection signals in the drawing method. It is a schematic sectional drawing which shows the process in which the fine pattern is transcribe | transferred and formed on the magnetic disc medium using the imprint mold provided with the fine pattern drawn by the electron beam drawing method. It is a cross-sectional schematic diagram showing processes (A) and (B) in which a magnetic pattern is transferred and formed on a magnetic disk medium using a magnetic transfer master having a fine pattern drawn by an electron beam drawing method.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The mold as an embodiment of the present invention shown in FIGS. 1 and 2 is an example of an imprint mold for a magnetic disk medium (hard disk).

  As shown in FIG. 1 and FIG. 2, servo areas 12 and data areas 15 are regularly arranged alternately in the circumferential direction on a fine pattern 9 for a magnetic disk medium having a fine concavo-convex shape. Has a servo pattern 14. The fine pattern 9 is formed in an annular region excluding the outer peripheral portion 10a and the inner peripheral portion 10b on the disc-like substrate 10 (circular base). The servo pattern 14 is formed in concentric tracks on the substrate 10 at equal intervals in narrow servo areas 12 extending in the radial direction from the central portion in each sector. In general, as shown in FIG. 1, the servo area 12 is formed in an arc shape extending in the radial direction.

  FIG. 2 is a partially enlarged view of a hard disk pattern as an example of a discrete track medium. In the illustrated servo pattern 14, for example, rectangular fine servo elements 13 corresponding to preambles, addresses, and burst signals are arranged on concentric tracks T 1 to T 4. One servo element 13 has a track width that is larger than the irradiation diameter of the electron beam with one track width, and a part of the servo elements 13 of the burst signal are arranged so as to be shifted by a half track so as to straddle adjacent tracks. .

  In addition to the servo pattern 14 formed in the servo area 12 as described above, a groove pattern 16 extending in the track direction is provided at each data track portion in the data area 15 so as to separate adjacent tracks T1 to T4 into a groove shape. It extends in the rotation direction (circumferential direction) and is formed concentrically.

  Although not shown, as an example of the hard disk pattern of the bit pattern medium, each track in the data area 15 has a dotted dot pattern (bit pattern) extending in the rotation direction (circumferential direction) to be concentric. Formed.

  As will be described later with reference to FIG. 5, the servo element 13 has a track width direction length (usually a track width W) divided into a plurality of n sections, and a plurality of m sections divided into n sections are drawn by one rotation of the substrate 10. The servo element 13 for one track is drawn by a plurality of n / m rotations of the substrate 10, and the groove pattern 16 is divided as necessary according to the division number n of the servo element 13. Is not necessary, the image is drawn by one rotation of the substrate 10, and when divided, the image is drawn by a plurality of rotations of the substrate 10 according to the number of divisions. In the embodiment of FIG. 5, the servo element 13 is divided into four (n = 4), two sections (m = 2) are drawn by one rotation of the substrate 10, and the servo elements 13 for one track are drawn by two rotations. In this example, the groove pattern 16 is drawn in any one rotation without being divided.

  For drawing the servo element 13 in the servo area 12 of the fine pattern 9 and the groove pattern 16 in the data area 15, the substrate 10 coated with the resist 11 on the surface is placed on a rotating stage 31 (see FIG. 4) described later. While rotating, for example, the servo element 13 and the groove pattern 16 are sequentially scanned and drawn by the electron beam EB in order from the inner track to the outer track, or in the opposite direction, and the resist 11 is irradiated and exposed. .

  FIG. 3 shows the relationship between the substrate rotation speed N and the radius r in the drawing of the inner track and the outer track in the fine pattern drawing of the substrate 10, and the basic characteristic indicated by the chain line is the innermost track (radius r1). Rotational control is performed so that the rotational speed N2 of the outermost track (radius r2) becomes slower in inverse proportion to the radius. Actually, the rotational speed N is not changed and adjusted for each track, but a plurality of tracks (for example, 8 tracks) are drawn corresponding to the radial deflectable range of the electron beam EB as shown by the solid line. Later, when the rotary stage 31 is mechanically moved in the radial direction, control is performed to change the rotational speed N of the rotary stage 31 stepwise in conjunction with this. Then, at least during the rotation of the substrate 10, the rotation speed N (rotation speed) is driven at a constant value without changing.

  As described above, the movement of the drawing portion in the radial direction in the drawing region of the fine pattern 9 on the substrate 10, that is, the track movement, has the same linear velocity in the entire drawing region in both the outer peripheral portion and the inner peripheral portion of the substrate 10. As described above, the rotational speed N of the rotary stage 31 is adjusted so as to be slow when drawing the outer circumference track and faster when drawing the inner circumference track. This is advantageous in that a uniform dose is obtained in the drawing of the electron beam EB and that the drawing position accuracy is ensured.

<Electron beam drawing device>
An embodiment of an electron beam drawing apparatus for carrying out an electron beam drawing method of the present invention to be described later will be described. FIG. 4 is a schematic configuration diagram of the electron beam drawing apparatus.

  The electron beam drawing apparatus 100 includes an electron beam irradiation unit 20 that irradiates the substrate 10 with an electron beam, a drive unit 30 that rotates and linearly moves the substrate 10, and drive control that performs mechanical drive control in the drive unit 30. An electron optical unit that generates a drawing clock, outputs a timing signal for the operation of the electron beam irradiation unit 20 and the drive unit 30, and performs electron optical control of the emitted electron beam in the electron beam irradiation unit 20. A system control unit 60 and a data sending device 5 for sending design data related to the fine pattern 9 to be drawn to the formatter 50 are provided. Data is transmitted and received between the data sending device 5 and the drive control unit 40 and the electron optical system control unit 60.

  The electron beam irradiation unit 20 deflects the electron beam EB in the lens barrel 27 in a direction X (hereinafter referred to as a circumferential direction) and a radial direction Y (see FIG. 5) perpendicular to the radial direction. A deflecting means 22 and 23, and an aperture 24a and a blanking 24b (deflector) are provided as blanking means 24 for on / off control of the irradiation of the electron beam EB, and the drawing on / off means is provided by the blanking means 24. The electron beam EB for exposure is irradiated by the drawing on signal (blanking / off signal) in the drawing on / off control, and the exposure is not performed by the drawing off signal (blanking / on signal). . Further, a condenser lens 25 (electromagnetic lens) for changing the irradiation dose of the electron beam EB by adjusting the aperture of the electron beam EB is set above the deflection means 22 and 23, and a beam diameter of the electron beam EB is changed and set below the deflection means 22 and 23. Objective lens 26 (electromagnetic lens) is provided.

  Thereby, the electron beam EB emitted from the electron gun 21 is subjected to deflection means 22, 23, a condenser lens 25, an objective lens 26, and the like so that the beam irradiation dose and the beam diameter are adjusted and the mold master 10 coated with the resist 11. Irradiated and shielded upward, deflected and scanned in the XY directions. It should be noted that in the state in which the exposure with the electron beam EB is performed and the resist 11 is exposed, the irradiation position is fixed without performing the beam deflection by the deflection means 22 and 23 and depends on the rotation of the substrate 10. The resist 11 is configured to perform arc-shaped exposure drawing at the speed (the above-mentioned constant linear speed). Then, beam deflection by the deflecting means 22 and 23 is performed in a period in which drawing is turned off in which the irradiation of the electron beam EB is blocked.

  The electron beam irradiation unit 20 and the driving unit 30 described later are configured in a vacuum chamber whose inside is depressurized, and perform pattern drawing by irradiating the mold substrate 10 installed in the vacuum chamber with the electron beam EB. It is configured as follows.

  The aperture 24a in the blanking means 24 has a through-hole through which the electron beam EB passes in the center, and the blanking 24b is activated when a drawing on signal (blanking / off signal) is input in response to a drawing on / off signal input. The electron beam EB is allowed to pass through the aperture 24a without being deflected, and irradiated with the beam. On the other hand, the electron beam EB is deflected and passed through the aperture 24a when a drawing off signal (blanking on signal) is applied. Without being interrupted by the aperture 24a, the electron beam EB is not irradiated.

  The drive unit 30 includes a rotary stage 31 that supports the substrate 10 in a housing 43 in which the lens barrel 27 is disposed on the upper surface, and a spindle motor 32 that has a motor shaft provided so as to coincide with the central axis of the stage 31. The rotary stage unit 33 is provided, and linear movement means 34 for linearly moving the rotary stage unit 33 in one radial direction of the rotary stage 31. The linear moving means 34 includes a rod 35 that is screwed into a part of the rotary stage unit 33 and is precisely threaded, and a pulse motor 36 that drives the rod 35 to rotate forward and backward. The stage unit 33 is provided with an encoder 37 that outputs an encoder signal corresponding to the rotation angle of the rotary stage 31. The encoder 37 includes a rotating plate 38 that is attached to the motor shaft of the spindle motor 32 and has a large number of radial slits, and an optical element 39 that optically reads the slits and outputs an encoder signal.

  The drive control unit 40 sends drive control signals to the driver 41 of the spindle motor 32 and the driver 42 of the pulse motor 36 of the drive unit 30, and controls these drives.

  The formatter 50 includes a reference clock generation unit 51 that generates an unchanging basic clock, a drawing clock generation unit 52 that generates a drawing clock (see FIG. 5), and a deflection unit 22 of the electron beam irradiation unit 20 based on the drawing clock. , 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23. A timing control unit 55 that receives the signal and controls operation timing (data distribution timing) is provided.

  The drawing clock generation unit 52 includes a changing unit 56 for changing the frequency of the drawing clock according to the radial position of the substrate 10, and the number of drawing clocks for drawing one servo element 13 and the groove pattern 16 is the inner and outer circumferences. Use the same setting.

  The data sending device 5 stores drawing design data (data indicating a drawing pattern and drawing timing) of the fine pattern 9 to be drawn, such as a hard disk pattern, and a drive control unit 40, a formatter 50, and an electro-optical system control unit 60. The drawing design data signal is sent to the.

  The electron optical system control unit 60 sends control signals to the condenser lens 25 and the objective lens 26 by the electromagnetic lens of the electron beam irradiation unit 20, and controls the electro-optical characteristics of these electromagnetic lenses.

  In the electron beam drawing apparatus 100, a drawing design data signal is input from the data sending device 5 to the formatter 50, and the formatter 50 converts the drawing design data into off / on control (drawing on / off control) of the blanking means 24, The control signals are distributed to the amplifiers 28 and 29 and the drivers 41 and 42 as control signals for the XY deflection control of the electron beam EB by the deflection means 22 and 23, the rotation speed control of the rotary stage 31, and the like. It is transmitted at a predetermined timing in synchronization with the encoder signal input from the encoder 37. Based on the signal from the formatter 50, the blanking means 24, the deflecting means 22, 23, the spindle motors 32, 36, etc. are driven to draw a desired fine pattern 9 on the entire surface of the substrate 10.

  Further, a drawing design data signal is input from the data sending device 5 to the electron optical system control unit 60, and a control signal (operation current value) for the condenser lens 25 and the objective lens 26 is set according to the fine pattern 9 to be drawn, The beam irradiation dose and the beam diameter of the electron beam EB are initially set to achieve both the drawing accuracy and the drawing speed suitable for the pattern form. At the same time, the rotation speed by the spindle motor 32, the deflection means 23, and the radial drawing by the pulse motor 36 are performed. Change and control the feed. The beam irradiation dose and the beam diameter are initially set at least until the drawing of the substrate 10 is completed, and the beam irradiation is performed without being changed during the drawing.

  FIG. 5 is a diagram showing an example of a drawing method corresponding to the shapes of the servo element 13 and the groove pattern 16 by the electron beam drawing method of the present invention. In the illustrated case, the servo elements 13a to 13d have a width W of one track. It is divided into four (n = 4), and two sections (m = 2) are drawn by one rotation of the substrate 10, and the first and second servo elements 13a and 13b for one track are irradiated reference positions of the electron beam EB. Is drawn in two rotations of R1 and R2 rotations that differ by a predetermined amount (half track width W / 2) in the radial direction, and the groove pattern 16 is not divided and is drawn in one rotation of R1. ing.

  Concretely, it demonstrates in order based on FIG. FIG. 5A shows the drawing operation of the electron beam EB in the radial direction Y (outer peripheral direction) and the circumferential direction X (opposite to the rotation direction A) of the electron beam EB, and FIG. Deflection signals Def (Y1) and Def (Y2) in the radial direction Y of the revolution are set in (C). Deflection signals Def (X1) and Def (X2) in the circumferential direction X in the R1 round and R2 round are in (C). The R1 and R2 on / off operations of the irradiation signal of the electron beam EB are shown, (E) shows a drawing clock signal, and (F) shows an invariant basic clock signal. The horizontal axis of (A) indicates the phase of the substrate 10, and the horizontal axes of (B) to (F) indicate time. When the irradiation signal (D) is on, the resist 11 on the substrate 10 is exposed by irradiating the electron beam EB when the blanking means 24 is off, and when the irradiation signal is off, the blanking means 24 is off. When the ranking means 24 is on, the electron beam EB is blocked and the resist 11 on the substrate 10 is not exposed.

  The basic clock signal (F) is a constant clock signal that does not change depending on the situation, and is generated in the formatter 50. The drawing clock signal (E) is based on the basic clock signal, and as shown in FIG. 3, the rotation speed N of the rotary stage 31 changes between the inner track drawing and the outer track drawing. Also, the clock width (clock length) is adjusted in accordance with the change in the rotation speed N so that the number of clocks in one rotation (one turn) is the same. That is, the clock width is changed according to the radius r so as to be narrow at the inner track and wide at the outer track for each predetermined track. Then, the dimensional and temporal width in the circumferential direction X (rotation direction A) is defined by the number of clocks of the drawing clock signal, and the servo elements 13a to 13d and the groove pattern 16 are drawn with the same number of drawing clocks on the inner and outer circumferences. Thereby, the number of drawing clocks at the same angle (phase) is the same on the inner peripheral side and the outer peripheral side, so that a similar pattern can be drawn easily. Unlike the above, when the same clock width is used on the inner and outer circumferences, the element width may not be an integral multiple of the clock width in the middle track, whereas in this embodiment, it is always an integer. Servo elements whose pattern width changes minutely can be easily drawn since the double is maintained.

  In FIG. 5, first, in the rotation of the substrate 10 in which the substrate rotation speed N is set to the predetermined rotation speed according to FIG. 3, the predetermined position in the radial direction set corresponding to the R1 round, With the radial position of the electron beam EB adjusted to the reference deflection position where the Y-direction deflection signal Def (Y1) in (B) is set to 0, the circumferential irradiation position reaches the drawing start position of the servo element 13a. When the irradiation signal (D) is turned on at point a, the resist 11 is irradiated with the electron beam EB, and drawing of the first section of the servo element 13a is started (drawing on control).

  The deflection signals Def (Y1) and Def (X1) in the Y direction and the X direction in (A) and (B) are fixedly irradiated with the electron beam EB without changing at a constant value, so that the A direction of the substrate 10 is changed. Depending on the rotation, the resist 11 is exposed to the substantially straight first section.

  When the irradiation position reaches the point b reaching the drawing width of the servo element 13a, the irradiation of the electron beam EB is stopped by temporarily turning off the irradiation signal (drawing off control), and the deflection signal Def (Y1) in (B). Is deflected by one section (W / 4) in the radial direction (−Y) to deflect the irradiation position, and the deflection signal Def (X1) in (C) is changed to the circumferential direction (−X ), The irradiation position is deflected by varying the element width (1T). Thereby, the irradiation position of the electron beam EB is deflected so as to follow the drawing start point of the second section of the servo element 13a, and the electron beam EB is irradiated by turning on the irradiation signal after the point b. Drawing of the second section 13a is started, and drawing is ended at point c.

  In this case, the interval between the first servo element 13a and the second servo element 13b (the interval between the other servo elements is the same) is set to be the same as the width T of the servo element 13a, and the electron beam EB is deflected. The time required is described as being very short (substantially 0 in FIG. 5).

  At point c, the irradiation of the electron beam EB is stopped by temporarily turning off the irradiation signal, and the deflection signal Def (Y1) in (B) is changed by one section (W / 4) in the radial direction (+ Y). Then, the irradiation position is deflected, and further, the deflection signal Def (X1) in (C) is changed in the same direction as the rotation direction A in the circumferential direction (+ X) by the element width (1T) to deflect the irradiation position. Thereby, the irradiation position of the electron beam EB is deflected so as to return to the drawing start point of the first section of the second servo element 13b, and the electron beam EB is irradiated when the irradiation signal is turned on after the point c. Drawing of the first section 13b is started, and the drawing is ended at the point d.

  At the point d, by performing deflection control in the radial direction Y and the circumferential direction X in the same manner as the point b, the irradiation position of the electron beam EB follows the drawing start point of the second section of the servo element 13b. When the irradiation signal is turned on after point d, the electron beam EB is irradiated, drawing of the second section of the servo element 13b is started, and drawing is ended at point e.

  After the point e, the deflection in the radial direction Y is adjusted to the radial position of the groove pattern 16 to be drawn next, and the deflection in the circumferential direction X is controlled to return to the reference position of the R1 round. When the irradiation position of the electron beam EB reaches the drawing start point of the groove pattern 16 as the substrate 10 rotates, drawing exposure of the groove pattern 16 is started by turning on the irradiation signal, and the data area 15 Irradiation continues until the drawing end point according to the length.

  Next, when the exposure for the R1 round is completed and the R2 round of the next rotation is started, the Y-direction deflection signal Def (Y2) of (B) is a predetermined radial position set corresponding to the R2 round, That is, in the state where the radial position of the electron beam EB is adjusted to the deflection position where the Y-direction deflection signal Def (Y2) in (B) is set with reference to the radial position of the third section, the circumferential irradiation position is the servo element. The electron beam EB is irradiated by turning on the irradiation signal (D) at the point a reaching the drawing start position 13a, and drawing of the third section of the servo element 13a is started.

  Thereafter, the Y-direction deflection signal Def (Y2) in (B) has the same characteristics as those of the points b to c in the R1 rotation, and the X-direction deflection signal Def in (C) is based on the radial position of the third section. For (X2), similarly, the deflection control of the R2 round is performed, and the third section and the fourth section of the first servo element 13a are exposed. Further, the third and fourth sections of the second servo element 13b are exposed by performing deflection control of the points c to e of the R2 round with the same characteristics as the points a to c of the round R2.

  Further, the third servo element 13c and the fourth servo element 13d of the third and fourth sections are controlled by performing deflection control of the points e to i of the R2 circuit with the same characteristics as the points a to e of the R2 circuit. These exposures are performed in order.

  As described above, the servo element 13 for one track is divided into four, and the two sections are drawn by one rotation, so that a fine pattern for one track is drawn by a total of two rotations. Under the same rotation speed, the same period of time can be obtained in half the time by performing the exposure during one rotation in the period when the exposure is paused at the element interval as compared with the case of drawing one section at one rotation. It can perform exposure drawing.

  After drawing one track, it moves to the next track and draws in the same manner, and the servo area 12 and the data area 15 of the desired fine pattern 9 are drawn in the entire area of the substrate 10. The track movement of the electron beam EB is performed by linearly moving the rotary stage 31 in the radial direction Y. The movement is performed for each drawing of one track or for each drawing of a plurality of tracks (for example, eight tracks) according to the deflectable range in the radial direction Y of the electron beam EB.

The drawing width (substantially exposed width) by the electron beam EB has a characteristic that it becomes wider than the irradiation beam diameter depending on the irradiation time. In order to draw the final element width, a predetermined width that is the drawing width is used. In order to scan with the irradiation dose, the irradiation dose is defined by setting the relative linear velocity and the scanning velocity at the time of drawing the servo element 13 and the groove pattern 16.

  In the drawing control of FIG. 5, when drawing of each section of each element is completed, the time required for electron beam deflection by temporarily blocking the irradiation of the electron beam by an irradiation off (drawing off) signal. However, the deflection operation actually takes a very short time, and a gap is generated in the electron beam irradiation. However, the element shape drawn by the gap is not reduced, and the resist It is possible to draw without problems due to bleeding phenomenon. Furthermore, depending on the sensitivity of the resist 11, even if the irradiation of the electron beam EB is not turned off (blanking on), if the electron beam deflection operation is performed at a high speed, the electron beam moves on the resist surface at a high speed. However, the irradiation dose is small and the movement trajectory may not be exposed. In this case, irradiation may be continued.

  On the other hand, when the exposure drawing time (circumferential drawing length) is set to exceed the rotational movement time (circumferential moving length) with respect to the rotation of the substrate 10, that is, in the example of FIG. If the total drawing element width T is set to be the same as the total element spacing T, but the total drawing element width is set larger than that, the circumferential deflection signal Def (X) is the initial value. Although it will be delayed in the -X direction from the reference position, there is a time during which drawing is not performed in any of the rotating regions, and it is necessary to return the circumferential deflection signal to the reference position within that time. By controlling to advance from the reference position according to the above, such a pattern shape can be drawn, and is set according to the beam deflectable range or the like. Particularly in the case of a fine pattern having no drawing element in the data area 15, the deflection control can be corrected when passing through this data area.

The simulation result which compared the drawing time of the Example of this invention and the normal on-off drawing which exposes 1 beam width by 1 rotation of a board | substrate is shown.
Drawing pattern: hard disk pattern of 320 GB / 2.5 mm Drawing area: radius r = 14.50 mm to 31.50 mm
Substrate rotation speed: N = 900.0 rpm to 414.3 rpm
Number of element divisions: n = 4
Number of repetitions: m = 2
Whole drawing time: about 48 hours As a comparative example, the number of repetitions is m = 1, and other on-off drawing is the same, and the whole drawing time in this comparative example is about 96 hours. In the embodiment of the present invention, the drawing time is halved and the time is shortened.

  Although not shown in detail, the drawing of the fine pattern of the bit pattern media, that is, the servo pattern extending in the track width direction in the servo area and the dot pattern extending in the broken line shape in the circumferential direction of the track in the data area, The pattern is drawn in the same manner as the servo elements 13a to 13d in FIG. Further, in the drawing of the dot pattern, in the drawing of the groove pattern 16 in FIG. 5, the electron beam EB that is continuously irradiated is intermittently turned on and off by repeating the irradiation signal (blanking signal) for a short time. This can be realized by irradiating the target and drawing it like dots.

  Next, FIG. 6 shows a case where a fine concavo-convex pattern is transferred to a magnetic disk medium using an imprint mold 70 having a fine pattern drawn by the above-mentioned electron beam drawing method by the electron beam drawing apparatus 100 as described above. It is a schematic sectional drawing which shows the process in which it forms.

  In the imprint mold 70, the above-described resist 11 (not shown in FIG. 6) is applied to the surface of a substrate 71 made of a translucent material, and the fine pattern 9 is drawn. Thereafter, development processing is performed to form a concavo-convex pattern with a resist on the substrate 71. The substrate 71 is etched using the patterned resist as a mask, and then the resist is removed to obtain an imprint mold 70 having a fine uneven pattern 72 formed on the surface. As an example, the fine uneven pattern 72 includes a servo pattern 14 and a groove pattern 16 for discrete track media.

  Using this imprint mold 70, a magnetic disk medium 80 is produced by an imprint method. The magnetic disk medium 80 includes a magnetic layer 82 on a substrate 81, and a resist resin layer 83 for forming a mask layer is coated thereon. Then, the fine uneven pattern 72 of the imprint mold 70 is pressed against the resist resin layer 83, the resist resin layer 83 is cured by ultraviolet irradiation, and the uneven shape of the fine pattern 72 is transferred and formed. Thereafter, the magnetic layer 82 is etched based on the concavo-convex shape of the resist resin layer 83 to produce a magnetic disk medium 80 for discrete track media in which a fine concavo-convex pattern is formed by the magnetic layer 82.

  In the above description, the manufacture of discrete track media has been described. However, bit pattern media can also be manufactured in the same process.

  FIG. 7 shows a magnetic transfer master carrier 90 (mold) having a fine pattern drawn by the above-described electron beam drawing method by the electron beam drawing apparatus 100 as described above. FIG. 6 is a schematic cross-sectional view showing a process of magnetically transferring a magnetization pattern to manufacture a disk medium 85.

  The manufacturing process of the magnetic transfer master carrier 90 is almost the same as the manufacturing method of the imprint mold 70. The substrate 10 placed on the rotary stage 31 is coated with a positive or negative electron beam drawing resist 11 on the surface of a disk made of, for example, silicon, glass or quartz, and the electron beam is scanned on the resist 11. Then, a desired fine pattern 9 is drawn. Thereafter, the resist 11 is developed to obtain a substrate 10 having a fine concavo-convex pattern of the resist. This becomes a master disk of the master carrier 90 for magnetic transfer. The hard disk pattern that can be formed by magnetic transfer has a servo pattern that forms a magnetized pattern, not a fine pattern for discrete track media or bit pattern media that forms an uneven pattern on a magnetic recording medium as described above. It is a fine pattern.

  Next, a thin conductive layer is formed on the concavo-convex pattern surface of the master, and electroforming is performed thereon to obtain a substrate 91 having a concavo-convex pattern taking a metal mold. Thereafter, the substrate 91 having a predetermined thickness is peeled from the master. The uneven pattern on the surface of the substrate 91 is obtained by inverting the uneven shape of the master.

  After the back surface of the substrate 91 is polished, a magnetic layer 92 (soft magnetic layer) is coated on the uneven pattern to obtain a magnetic transfer master carrier 90. The convex or concave shape of the concave / convex pattern of the substrate 91 is a shape depending on the concave / convex pattern of the resist of the master.

  A magnetic transfer method using the magnetic transfer master carrier 90 manufactured as described above will be described. The magnetic disk medium 85 that is a transfer medium to which information is transferred is, for example, a hard disk, a flexible disk, or the like in which the magnetic recording layer 87 is formed on both surfaces or one surface of the substrate 86. Here, the magnetization of the magnetic recording layer 87 The perpendicular magnetic recording medium is formed so that the easy direction is perpendicular to the recording surface.

  As shown in FIG. 7A, an initial direct current magnetic field Hin is applied to the magnetic disk medium 85 in one direction perpendicular to the track surface in advance to cause the magnetic recording layer 87 to undergo initial direct current magnetization. Thereafter, as shown in FIG. 7B, the surface on the recording layer 87 side of the magnetic disk medium 85 and the surface of the magnetic layer 92 of the master carrier 90 are brought into close contact with each other, and the direction perpendicular to the track surface of the magnetic disk medium 85 is obtained. In addition, magnetic transfer is performed by applying a transfer magnetic field Hdu in the direction opposite to the initial DC magnetic field Hin. As a result, the magnetic field for transfer is sucked into the magnetic layer 92 of the master carrier 90, the magnetization of the magnetic layer 87 of the magnetic disk medium 85 corresponding to the convex portion is reversed, and the magnetization of the other portion is not reversed. Information (for example, servo signals) corresponding to the concavo-convex pattern of the master carrier 90 is magnetically transferred and recorded on the magnetic recording layer 87 of the disk medium 85. When magnetic transfer is also performed on the upper recording layer of the magnetic disk medium 85, an upper master carrier is brought into close contact with the upper recording layer, and magnetic transfer is performed simultaneously with the lower recording layer.

  Further, instead of applying the transfer magnetic field Hdu in the vertical direction, a transfer magnetic field is applied in the in-plane direction (parallel to the magnetic recording layer 87), and the concavo-convex pattern is formed on both sides (edges) of the convex magnetic layer 92. The perpendicular magnetization that occurs in response to this may be recorded.

  In the case of magnetic transfer to the in-plane magnetic recording medium, a master carrier 90 substantially the same as that for the perpendicular magnetic recording medium is used. In the case of this in-plane recording, the magnetization of the magnetic disk medium is preliminarily magnetized in one direction along the track direction in advance, and is in close contact with the master carrier for transfer in a direction substantially opposite to the initial DC magnetization direction. Magnetic transfer is performed by applying a magnetic field, the magnetic field for transfer is sucked into the convex magnetic layer of the master carrier 90, and the magnetization of the magnetic layer of the magnetic disk medium corresponding to the convex part is not reversed, As a result of reversal of the magnetization of the other portions, a magnetization pattern corresponding to the concavo-convex pattern can be recorded on the magnetic disk medium.

  The above-described manufacturing method of the imprint mold and the magnetic transfer master carrier using the electron beam writing method of the present invention described above is an example, and a fine pattern is drawn using the electron beam writing method of the present invention. The manufacturing method is not limited to the above as long as it undergoes a step of forming a concavo-convex pattern.

DESCRIPTION OF SYMBOLS 5 Data sending device 9 Fine pattern 10 Substrate 11 Resist 12 Servo area 13 Servo element 14 Servo pattern 15 Data area 16 Groove pattern 18 Lens barrel 20 Electron beam irradiation part 21 Electron gun 22, 23 Deflection means 24 Blanking means (Drawing on / Off means)
24a Aperture 24b Blanking 25 Condenser lens 26 Objective lens 28 Deflection amplifier 29 Blanking amplifier 30 Drive unit 31 Rotating stage 32 Spindle motor 37 Encoder 40 Drive control unit 50 Formatter 51 Reference clock generation unit 52 Drawing clock generation unit 54 Data distribution unit 55 Timing control unit 56 Changing unit 60 Electron optical system control unit 70 Imprint mold 80, 85 Magnetic disk medium 90 Master carrier 100 Electron beam drawing apparatus

Claims (6)

A fine pattern composed of elements larger than the irradiation diameter of the electron beam is obtained by scanning the electron beam with an electron beam lithography apparatus while rotating the rotary stage on a substrate coated with a resist and rotating the rotary stage. In the electron beam drawing method for drawing,
While rotating the substrate in one direction, with respect to the rotation of the substrate, an electron beam is emitted by a drawing-on signal at a predetermined rotation position of the substrate corresponding to the drawing start position of the element to be drawn based on the drawing data of the fine pattern. The first partition portion of the element divided into n in the radial direction is drawn by drawing on / off control in which fixed irradiation is performed, drawing is performed in the rotation direction depending on the rotation of the substrate, and drawing is stopped by a drawing off signal. In order to draw the second section of the element, the electron beam is returned to the drawing start position of the element by deflection in the same direction as the rotation direction of the substrate. Alternatively, after the substrate is moved in the radial direction of the substrate and the drawing by the drawing on / off control is performed m times (m ≧ 2) for the element, the next element is drawn. Migrated, an electron beam drawing method characterized by sequentially drawing the m partitions fraction of the n divided elements during one revolution of the substrate. The rotation speed of the rotary stage is controlled so that the linear velocity is constant so that the rotation speed of the rotation stage is inversely proportional to the radius of the drawing position and the inner track drawing is faster and the outer track drawing is slower.
The electron beam drawing control signal is generated based on a drawing clock signal generated in association with the rotation of the rotary stage, and the drawing clock signal is used to draw the number of clocks in one rotation of the rotary stage. 2. The electron beam writing method according to claim 1, wherein the method is performed by setting a constant value for each track regardless of the radius of the position. In order to realize the electron beam writing method according to claim 1 or 2,
A rotary stage that rotates a substrate coated with a resist, a drive control unit that keeps the substrate linear velocity constant according to the radius of the drawing position, and irradiation of an electron beam emitted from an electron gun The drawing on / off means by the blanking means for cutting off, the beam deflecting means for deflecting and scanning the electron beam in the rotation direction and the radial direction, the on / off signal for the drawing on / off means based on the drawing data signal, and the An electron beam drawing apparatus comprising: a formatter for outputting a deflection signal for the beam deflection means.   Manufacturing a process by drawing a desired fine pattern on a substrate coated with a resist by the electron beam drawing method according to claim 1 or 2 and forming a concavo-convex pattern according to the desired fine pattern. A method for producing a mold.   An in-line produced through a step of drawing a desired fine pattern on the substrate coated with the resist by the electron beam drawing method according to claim 1 and forming a concavo-convex pattern according to the desired fine pattern. A method for producing a magnetic disk medium, comprising using a print mold and transferring a concavo-convex pattern corresponding to the concavo-convex pattern provided on the surface of the mold.   A magnetic material produced through a step of drawing a desired fine pattern on a substrate coated with a resist by the electron beam drawing method according to claim 1 or 2, and forming a concavo-convex pattern according to the desired fine pattern. A method of manufacturing a magnetic disk medium, wherein a transfer master carrier is used, and a magnetic pattern corresponding to the concavo-convex pattern provided on the surface of the master carrier is magnetically transferred.

Images