JP2010232035A - Method and apparatus for electron beam lithography, method of manufacturing mold, and method of manufacturing magnetic disk medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electron beam lithography method in which drawing of a fine pattern can be made in high precision as prescribed on all surface of a substrate, and in a deflection control by a triangular wave deflection signal, drawing operation by electron beams is corrected and a photosensitized drawing of a prescribed element shape can be made rapidly and precisely with a constant dose. <P>SOLUTION: When, by controlling irradiation timing of electron beams EB by an output of an On/Off signal to a blanking means 24 and controlling the deflection operation of the electron beams EB by the output of a triangular wave deflection signal to a beam deflection means 22, drawing is made by scanning the element shape so as to paint it on a substrate 10 on which a resist 11 is coated, the On/Off signal is established so that the beam irradiation time by the operation of the blanking means may be short to the reference drawing time, and a triangular wave correction in which the amplitude of the triangular wave deflection signal is established large in inverse proportion to the shortening ratio of the beam irradiation time is carried out to make drawing. <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. Discrete track media in which adjacent data tracks are separated by groove patterns (guard bands) consisting of grooves to reduce magnetic interference between adjacent tracks in response to a demand for higher recording density. (DTM) is drawing attention. In the bit pattern media (BPM) proposed to further increase the density, magnetic bodies (single domain fine particles) constituting a single magnetic domain are physically isolated and regularly arranged, and one fine particle is arranged. It is a medium for recording 1 bit.

  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. In this electron beam drawing method, pattern drawing is performed by irradiating an electron beam corresponding to a pattern shape while rotating a substrate coated with a resist (for example, see Patent Document 1).

  In the electron beam drawing method disclosed in Patent Document 1, for example, when drawing a rectangular or parallelogram element extending in the width direction of a track constituting a servo pattern, the electron beam is deflected in the radial direction while being vibrated at high speed in the circumferential direction. Then, this element is scanned and drawn so as to be filled.

JP 2004-158287 A

  By the way, in the electron beam drawing method as described above, XY deflection control for deflecting the electron beam in the track width direction and the circumferential direction is performed based on the input of the triangular wave deflection signal, and the electron beam irradiation is turned on / off. Control is performed by inputting an on / off signal to the blanking mechanism, and a predetermined pattern shape is drawn and exposed.

  However, in the XY deflection control based on the above-described triangular wave deflection signal, the deflection of the electron beam is started at the rising edge of the triangular waveform, the deflection direction of the electron beam is changed to the reverse direction at the apex, and the deflection is terminated at the origin. However, the actual movement of the electron beam accurately follows this triangular wave shape and does not start and end deflection, but shifts, and the deflection direction changes according to the apex shape of the triangular wave. As a result of a so-called “rounding” that changes in a curve due to a follow-up delay without changing to, there is a problem that an accurate element shape cannot be drawn and exposed with an appropriate exposure amount. .

  For example, a description will be given of an electron beam drawing mode using a conventional triangular wave deflection signal with reference to FIG. In this mode, a rectangular (designed shape) element 3 as shown in FIG. 9 (E) is drawn. While the electron beam EB is oscillated minutely in the circumferential direction (X direction), FIG. 9B and the electron beam EB as shown in FIG. 9C based on the blanking signal BLK (ON / OFF signal) shown in FIG. 9 and the Y-direction deflection signal Def (Y) based on the triangular wave signal shown in FIG. The image is drawn by performing a deflection operation in the radial direction (Y direction). FIG. 9D shows a drawing clock signal, and when drawing the element 3, the drawing is set to be performed at a time T1 set at a fixed number N of clocks.

  First, at the timing of point a, the blanking signal BLK in FIG. 9A is turned off from on, the shielding by the blanking means described later is released, and the irradiation of the electron beam EB is started simultaneously. A deflection signal Def (Y) based on the triangular wave signal B) is output to deflect and move the electron beam EB in the (−Y) direction. Then, at the timing of point b, the blanking signal BLK in FIG. 9A is turned from OFF to ON, the blanking means is shielded and the irradiation of the electron beam EB is completed, and at the same time, the blanking signal BLK in FIG. The deflection control is set so that the voltage of the triangular wave deflection signal Def (Y) changes from -V1 to 0, the Y-direction deflection returns to the drawing start point side of the reference position, and moves to the drawing start position of the next element. Yes.

  In principle, the shape of the element 3 is changed from one end to the other while the electron beam EB is reciprocally oscillated by the blanking signal BLK in FIG. 9A and the triangular wave deflection signal Def (Y) in FIG. 9B. It can be drawn by scanning to fill the shape by deflecting to the end.

  However, in practice, as shown in FIG. 9C, the deflection operation of the electron beam EB operates with an overall time delay due to electrical and electronic circuit elements, and in addition to the delay. There is a start-up delay at the deflection start point, and after being deflected substantially linearly according to the hypotenuse of the triangular wave shape, at the apex of the triangular waveform, it reached the apex of the triangular wave signal over time and turned back to an acute angle. The deflection movement of the electron beam cannot follow this, and it becomes a deflection operation in which the electron beam is folded back into an R shape before reaching the apex.

  The deflection operation amount Y1 in FIG. 9C corresponding to the amplitude V1 (difference between the highest voltage and the lowest voltage) of the triangular wave deflection signal Def (Y) in FIG. 9B described above is shown in FIG. The Y-direction dimension Y0 of the element 3 is set so as to correspond to the deflection operation amount that can be scanned.

  First, in the actual deflection operation of FIG. 9C as described above, since the irradiation of the electron beam EB is completed at the point b, the deflection operation amount is insufficient, and the beam cannot be scanned into a predetermined shape. In addition to having a problem, the electron beam EB reciprocates at the reference position from the point a until the deflection operation is performed, and this portion has a problem of overexposure (dose amount overshoot).

  The above basic problem is that the blanking signal BLK of FIG. 9A is delayed by d1 as a whole, and the timing of turning off and turning on the points a and b is delayed as shown by the one-dot chain line. 9C can be solved by correcting the drawing so that the drawing operation is performed in accordance with the entire deflection operation of FIG. 9C. However, the deviation from the linear characteristic based on the operation characteristic deviating from the triangular wave shape at the start point and the end point of the deflection operation. The non-uniform drawing due to the non-uniform beam scanning caused by the deflection movement is not solved.

  As a result, the drawing speed near the vertex near the end of drawing, that is, near the pattern end position is slow, and this part becomes overdose, causing a phenomenon that the photosensitive pattern shape after development becomes larger than the set dimension, The drawing accuracy decreases.

  For example, when narrow drawing elements are closely arranged adjacent to each other in the circumferential direction of the track, such as an address signal or a preamble signal of a servo pattern, the adjacent signals approach and the signal reading accuracy decreases. On the other hand, in areas where beam scanning is insufficient, the dose amount is underdeveloped, and the photosensitive pattern shape after development becomes a photosensitive shape that is shrunken from the set size, and it is necessary to improve the accuracy of the drawing shape based on the triangular wave deflection signal .

  In view of the above circumstances, the present invention can perform drawing of a fine pattern on the entire surface of a substrate with high accuracy as prescribed. In the deflection control using a triangular wave deflection signal, the drawing operation by an electron beam is corrected, and photosensitive drawing of a predetermined element shape is performed. It is an object of the present invention to provide an electron beam drawing method and an electron beam drawing apparatus for performing electron beam drawing that can be executed at high speed and accurately with a constant dose amount over the entire substrate. .

  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 irradiates an electron beam corresponding to a drawing shape while rotating the rotary stage on a substrate coated with a resist and placed on the rotary stage.
While controlling the irradiation timing of the electron beam by the output of an on / off signal to the blanking means for blocking the electron beam irradiation,
In the electron beam drawing method of scanning and drawing the electron beam so as to fill the element shape of the fine pattern by controlling the deflection operation of the electron beam by outputting a triangular wave deflection signal to the beam deflecting means,
With respect to a reference drawing time assigned for drawing the element, electron beam irradiation is started by the turning-off operation of the blanking means, and the beam irradiation time for ending the electron beam irradiation by the on-operation is shortened. Set the on / off signal,
The amplitude of the triangular wave deflection signal with respect to the beam deflection means is set to be large in inverse proportion to the shortening ratio of the beam irradiation time with respect to the reference amplitude of the triangular wave deflection signal required to draw the element,
Further, the output timing of the on / off signal to the blanking means is set so that the beam irradiation time is located within the operation period in which the electron beam is deflected based on the triangular wave deflection signal output to the beam deflecting means. It is characterized by doing.

  In the drawing method, the shortening of the beam irradiation time in the blanking means ends the irradiation of the electron beam with a delay amount of an output timing of an off signal for starting the irradiation of the electron beam with respect to the reference drawing time. This can be done by setting the delay amount of the output timing of the ON signal small.

  In the drawing method, the beam irradiation time in the blanking means can be shortened by subtracting an integer number of clocks of the drawing clock signal corresponding to the reference drawing time.

  At that time, it is preferable to subtract the number of clocks of the irradiation start point and the irradiation end point of the drawing clock signal corresponding to the reference drawing time to set the irradiation start point to be delayed and the irradiation end point to be advanced. .

  Further, 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 off-signal and the triangular wave deflection signal for the beam deflection means are created based on a drawing clock signal generated in association with the rotation of the rotary stage, and the drawing clock signal is generated in one rotation of the rotary stage. The number of clocks is preferably a constant value regardless of the radius of the drawing position.

  Further, in the above drawing method, while rotating the substrate in one direction, the electron beam is oscillated minutely in a radial direction of the substrate or in a direction orthogonal to the radial direction, and the triangular wave is orthogonal to the vibration direction. It is preferable to draw the element while deflecting based on a deflection signal.

  In order to realize the above-described electron beam drawing method, an electron beam drawing apparatus according to the present invention includes a rotary stage that rotates a substrate coated with a resist, and blanking means that blocks irradiation of an electron beam emitted from an electron gun. And a beam deflector for deflecting and scanning the electron beam, and a formatter for outputting an on / off signal for the blanking means and a triangular wave deflection signal for the beam deflector based on a drawing data signal. .

  In the electron beam drawing apparatus, the blanking means finishes the irradiation of the electron beam by a delay amount of an output timing of the off signal for starting the irradiation of the electron beam in the on / off signal to the blanking means. It is possible to provide a delay circuit that shortens the beam irradiation time by setting the delay amount of the output timing of the ON signal to be small.

  The formatter may reduce the beam irradiation time for the blanking means by subtracting an integer number of clocks of a drawing clock signal corresponding to a reference drawing time.

  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 irradiation timing is applied to a substrate coated with a resist and placed on a rotary stage while the electron beam is irradiated corresponding to the drawing shape while rotating the rotary stage. Is controlled by the output of an on / off signal to the blanking means for blocking electron beam irradiation, and the electron beam deflection operation is controlled by the output of a triangular wave deflection signal to the beam deflecting means, thereby making the electron beam a fine pattern. When scanning and drawing to fill the element shape of the element, irradiation of the electron beam is started by turning off the blanking means with respect to the reference drawing time assigned to drawing this element, and by turning on the electron, The on / off signal so that the beam irradiation time for ending the beam irradiation is shortened. And setting the amplitude of the triangular wave deflection signal with respect to the beam deflection means in inverse proportion to the shortening ratio of the beam irradiation time with respect to the reference amplitude of the triangular wave deflection signal required for drawing the element, and further, the beam deflection means The output timing of the on / off signal to the blanking means is set so that the beam irradiation time is located within the operation period in which the electron beam is deflected based on the triangular wave deflection signal output to the triangular wave. Designed on the entire surface of the board by reducing the drawing accuracy due to the deflection of the deflection signal, and by using the part that changes with the linear characteristics of the beam deflection operation, and making corrections with the triangular wave deflection signal with simple control. A fine pattern can be drawn at high speed with high accuracy, and the drawing time can be shortened by improving the drawing efficiency.

  Further, in the above drawing method, the beam irradiation time in the blanking means is shortened by the ON signal for ending the electron beam irradiation based on the delay amount of the output timing of the OFF signal for starting the electron beam irradiation with respect to the reference drawing time. When the output timing delay amount is set to be small, correction associated with the triangular wave deflection signal can be performed with simple control by simple delay control.

  Further, in the above drawing method, when the beam irradiation time in the blanking means is shortened by subtracting the integer number of clocks of the drawing clock signal corresponding to the reference drawing time, particularly in the reference drawing time. By subtracting the number of clocks at the irradiation start point and irradiation end point of the corresponding drawing clock signal, the irradiation start point is delayed, and the irradiation end point is set to be advanced so that the triangle wave deflection signal is accompanied by simpler control. Correction can be performed.

  At that time, the rotation speed of the rotary stage is controlled so that the linear velocity is constant so that the rotational speed of the rotary 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. An off signal and a triangular wave deflection signal for the beam deflection means are created based on a drawing clock signal generated in conjunction with the rotation of the rotary stage, and the drawing clock signal is calculated based on the number of clocks in one rotation of the rotary stage. If a constant value is used regardless of the radius, the correction associated with the triangular wave deflection signal can be easily performed with high accuracy. In addition, the dose amount can be equalized between the inner circumference drawing and the outer circumference drawing, depending on the radius position. Control can be easily performed with high accuracy.

  In the above drawing method, while rotating the substrate in one direction, the electron beam is oscillated minutely in the radial direction of the substrate or in the direction orthogonal to the radial direction, and the triangular wave deflection signal is converted in the direction orthogonal to the vibration direction. This can be applied optimally when the element is drawn based on the deflection.

  On the other hand, the electron beam drawing apparatus of the present invention includes a rotating stage for rotating a substrate coated with a resist and blanking means for blocking irradiation of an electron beam emitted from an electron gun in order to realize an electron beam drawing method. And a beam deflector for deflecting and scanning the electron beam, and a formatter for outputting an on / off signal for the blanking means and a triangular wave deflection signal for the beam deflector based on the drawing data signal. Drawing can be performed at high speed and with high accuracy, and drawing time can be shortened by improving drawing efficiency.

  In the above electron beam drawing apparatus, the blanking means has an on signal for ending the irradiation of the electron beam based on a delay amount of an output timing of the off signal for starting the irradiation of the electron beam in the on / off signal for the blanking means. When a delay circuit that shortens the beam irradiation time by setting a delay amount of the output timing is provided, correction associated with the triangular wave deflection signal can be executed by simple control with a simple configuration.

  Further, when the beam irradiation time for the blanking means is shortened by the formatter by subtracting the integer number of clocks of the drawing clock signal corresponding to the reference drawing time, the configuration is further simplified. Correction according to the triangular wave deflection signal can be executed by simple control.

  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 having 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. It is a one part enlarged view of a fine pattern. It is a characteristic view which shows the relationship between drawing radius position and board | substrate rotation speed. It is a figure which shows various signals (A)-(D), such as a deflection signal, in the 1st drawing system including the triangular wave correction of the element which comprises a fine pattern. It is a figure which shows various signals (A)-(D), such as a deflection signal in the 2nd drawing system including the triangular wave correction | amendment of the element which comprises a fine pattern. 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. 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 a process in which a magnetic pattern is transferred and formed on a magnetic disk medium using a magnetic transfer master provided with a fine pattern drawn by an electron beam drawing method. It is the figure and drawing figure (E) which show various signals (A)-(D), such as a deflection signal, in the conventional drawing system of the element which comprises a fine pattern.

  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 a magnetic transfer master carrier.

  As shown in FIGS. 1 and 2, a fine pattern for a magnetic disk medium having a fine concavo-convex shape is composed of servo patterns 12 formed in a plurality of servo areas, and a data area 15 is formed between the servo patterns 12. The disc-shaped substrate 10 (circular base) is formed in an annular region excluding the outer peripheral portion 10a and the inner peripheral portion 10b.

  The servo pattern 12 is formed in concentric tracks on the substrate 10 at equal intervals in each sector in a narrow area extending almost radially from the center. In the case of the servo pattern 12 in this example, the servo pattern 12 is formed in a curved radial shape continuous in the radial direction. As illustrated in FIG. 2 in which a part thereof is enlarged, rectangular fine servo elements 13 corresponding to, for example, a preamble, an address, and a burst signal are arranged on the concentric tracks T1 to T4. 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. .

  The servo element 13 for one track is drawn by one rotation of the substrate 10, and when the first track T1 or the third track T3 in FIG. 2 is drawn, the hatched element 13 is drawn. Are drawn in order. Servo elements 13 shifted by a half track across adjacent tracks T2 or T4 are drawn at a time by shifting the drawing reference by a half track without being divided in half.

  In a discrete track medium that has been attracting attention in recent years, in addition to the servo pattern 12 as described above, adjacent tracks T1 to T4 are separated into grooves in a guard band portion between data tracks in the data area 15. A groove pattern extending in the track direction is formed concentrically, and this groove pattern is drawn by separate drawing control.

  Drawing of each servo element 13 of the servo pattern 12 is performed, for example, on an inner peripheral track while the substrate 10 having the resist 11 coated on the surface is placed on a rotary stage 31 (see FIG. 6) described below and rotated. The elements 13 are sequentially scanned and drawn by the electron beam EB one track at a time in order 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 M and the radius r in drawing the inner track and the outer track in the pattern drawing of the substrate 10, and the basic characteristic indicated by the chain line is that of the innermost track (radius r1). The rotation is controlled so that the rotation speed M2 of the outermost track (radius r2) becomes slower in inverse proportion to the radius with respect to the rotation speed M1. Actually, the number of rotations M is not changed and adjusted for each track, but a plurality of tracks (e.g., 8 tracks) are drawn corresponding to the radial deflection range of the electron beam EB, as indicated 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 M of the rotary stage 31 stepwise in conjunction with this.

  As described above, the movement of the drawing portion in the radial direction in the drawing region of the substrate 10, that is, the track movement is performed so that the same linear velocity is obtained in the entire drawing region in both the outer peripheral side portion and the inner peripheral portion of the substrate 10. The rotational speed M of the rotary stage 31 is adjusted so as to be slow when drawing the outer track and faster when drawing the inner track. This is advantageous in that an equivalent dose amount including triangular wave correction in the drawing of the electron beam EB is obtained and that the drawing position accuracy is ensured.

  FIG. 4 is a diagram showing a first drawing method of the electron beam drawing method according to the present invention, and the triangular wave correction is performed based on the drawing method of FIG. 9 described above as the prior art. That is, also in the embodiment shown in FIG. 4, the rectangular-shaped (designed shape) element 3 (for example, corresponding to the pixel constituting the servo element 13) as shown in FIG. 9E is drawn. While the electron beam EB is oscillated minutely in the circumferential direction (X direction), the blanking signal BLK (on / off signal) shown in FIG. 4A and the Y direction by the triangular wave signal shown in FIG. On the basis of the deflection signal Def (Y), the electron beam EB is drawn by being deflected in the radial direction (Y direction) as shown in FIG. 4C.

  As described above, the number of drawing clocks for drawing the elements 3 of the same form (concave / convex pattern) constituting the same information signal is set at a fixed number of clocks N as shown in FIG. The drawing is set to be performed at the time T1.

  The triangular wave correction in drawing will be specifically described. First, for the blanking signal BLK of FIG. 4A, the irradiation time of the electron beam is such that the signal before correction indicated by a chain line turns from on to off at point a and turns off to on at point b after T1 time. Is set by delaying the irradiation start point of point a by the delay time d2 and delaying the irradiation end point of point b by the delay time d3.

  At that time, the delay time d2 at the irradiation start time is set to be greater than the delay time d3 (d2> d3). Thereby, the actual beam irradiation time T2 is set to be shorter than the reference time T1 by the difference (d2−d3) between the two delay times. The shortened beam irradiation time T2 corresponds to a period in which the vicinity of the operation start portion and the vicinity of the operation end portion of the beam deflection operation in FIG. .

  On the other hand, the deflection signal Def (Y) is corrected by the triangular wave signal shown in FIG. 4 (B), and the reference amplitude V1 (difference between the highest voltage and the lowest voltage) with respect to the reference signal shown in FIG. The amplitude V2 is set to increase in inverse proportion to the shortening ratio (T2 / T1) of the time T2. That is, the corrected amplitude V2 is set by [V2 = V1 × (T1 / T2)].

  The deflection signal Def (Y) in FIG. 4B is output at an initial timing corresponding to the reference time T1 from the point a to the point b, and is delayed from the output by a predetermined time as in FIG. The beam deflection operation is performed as shown in FIG. 4C, and the deflection operation amount Y2 increases at the same ratio as the amplitude V2 is set large. As described above, since the beam irradiation time T2 is shortened, the deflection operation amount during the beam irradiation time T2 becomes the reference operation amount Y1. In the drawing of the element 3, the bias signal is applied to the deflection signal Def (Y) in FIG. 4B so that the drawing reference point (drawing start position) matches the drawing start point when the blanking signal is turned off. Is added so that the maximum voltage (− direction) from the 0 point becomes the reference voltage V1.

  In the first drawing method, by the triangular wave correction as described above, the deflection signal Def of the triangular wave signal whose inclination is set large in the shortened beam irradiation time T2 according to the output of the blanking signal BLK. Based on (Y), the beam deflection speed increases. Then, by deflecting the beam irradiation time at a high deflection speed, the beam deflection amount is the same, and the same beam deflection amount is obtained, and the operation in the vicinity of the deflection start portion and the vicinity of the deflection end portion in the beam deflection operation is followed. The operation of the region where the performance is deteriorated is that the beam irradiation is interrupted and the actual beam irradiation is not performed, and the deflection operation in the actual beam irradiation uses the region having the linear movement characteristic, so that the operation is good and accurate. High drawing can be performed. As a result, it is possible to secure a certain dose amount by uniform exposure as well as the accuracy of the drawing shape, the photosensitive shape after development becomes a predetermined one, and the signal quality can be improved.

  Next, FIG. 5 is a diagram showing a second drawing method of the electron beam drawing method according to the present invention, and the triangular wave correction is performed based on the drawing method of FIG. 9 described above as the prior art. That is, also in the embodiment shown in FIG. 5, the rectangular (designed shape) element 3 as shown in FIG. 9E is drawn, and the electron beam EB is vibrated minutely in the circumferential direction (X direction). However, the blanking signal BLK (on / off signal) shown in FIG. 5 (A2) after the correction shown in FIG. 5 (A1) and the Y-direction deflection signal Def () using the triangular wave signal as shown in FIG. On the basis of Y), the electron beam EB is drawn by being deflected in the radial direction (Y direction) as shown in FIG.

  As described above, the number of drawing clocks for drawing the elements 3 having the same form (uneven pattern) constituting the same information signal is set at a fixed number of clocks N as shown in FIG. The drawing is set to be performed at the time T1.

  The triangular wave correction in drawing will be specifically described. First, for the blanking signal BLK in FIGS. 5A1 and 5A2, the signal before correction indicated by the chain line is turned from on to off at point a and turned off to on at point b after time T1. First, as shown in FIG. 5 (A1), the beam irradiation time T3 is corrected so as to be shorter than the reference time T1 by a predetermined value (2Δt). That is, the irradiation start point of point a is set with a delay of a predetermined time Δt, and the irradiation end point of point b is set earlier by a predetermined time Δt.

  As shown in FIG. 5D, the predetermined time Δt is shortened by setting the drawing clock number (N−2Δn) obtained by cutting the same predetermined number Δn at both ends from the constant drawing clock number N. ing.

  The circumferential length of the element 3 (track direction length) differs between the inner peripheral portion and the outer peripheral portion because it is formed in the same rotation angle range of the substrate 10, but the above-described element for drawing the element 3 As described above, since the number N of drawing clocks is set to the same number at the time of inner circumference drawing and at the time of outer circumference drawing, cutting the predetermined number Δn on both sides is different between the times of inner circumference drawing and outer circumference drawing. Even if the length is different, the beam irradiation time is set to be reduced at the same ratio.

  Then, the signal in which the beam irradiation time T3 is set to be shortened as described above is set with a delay as a whole by the delay time d4 as shown in FIG. That is, in the final blanking signal BLK, the irradiation start point is set with a delay of (Δt + d4) from the point a, and the irradiation end point is set with a delay of (d4−Δt) from the point b. Further, the shortened irradiation time T3 corresponds to a period in which the vicinity of the operation start portion and the vicinity of the operation end portion of the beam deflection operation in FIG. .

  On the other hand, the correction of the deflection signal Def (Y) by the triangular wave signal of FIG. 5B is performed by applying the reference amplitude V1 (difference between the highest voltage and the lowest voltage) with respect to the reference signal of FIG. The amplitude V3 is set to increase in inverse proportion to the shortening ratio (T3 / T1) of the time T3. That is, the corrected amplitude V3 is set by [V3 = V1 × (T1 / T3)].

  The deflection signal Def (Y) in FIG. 5B is output at an initial timing corresponding to the reference time T1 from the point a to the point b, and is delayed from the output by a predetermined time as in FIG. The beam deflection operation is performed as shown in FIG. 5C, and the deflection operation amount Y3 increases at the same ratio as the amplitude V3 is set large. As described above, since the beam irradiation time T3 is shortened, the deflection operation amount in the beam irradiation time T3 becomes the reference operation amount Y1. In the drawing of the element 3, the bias signal is applied to the deflection signal Def (Y) in FIG. 5B so that the drawing reference point (drawing start position) matches the drawing start point by turning off the blanking signal. Is added so that the maximum voltage (− direction) from the 0 point becomes the reference voltage V1.

  In the second drawing method, by the triangular wave correction as described above, the deflection signal Def of the triangular wave signal whose inclination is set large in the shortened beam irradiation time T3 according to the output of the blanking signal BLK. Based on (Y), the beam deflection speed increases. Then, by deflecting the beam irradiation time at a high deflection speed, the beam deflection amount is the same, and the same beam deflection amount is obtained, and the operation in the vicinity of the deflection start portion and the vicinity of the deflection end portion in the beam deflection operation is followed. The operation of the region where the performance is deteriorated is that the beam irradiation is interrupted and the actual beam irradiation is not performed, and the deflection operation in the actual beam irradiation uses the region having the linear movement characteristic, so that the operation is good and accurate. High drawing can be performed.

  Furthermore, as shown in FIG. 3, the rotation speed M of the substrate changes between the inner circumference drawing and the outer circumference drawing so that the number of revolutions at the outer circumference drawing is small and the time required for one rotation is increased, so that the same angle is obtained. The reference drawing time T1 of the element 3 formed in the range is set to be longer at the time of outer drawing, but the beam irradiation time T3 is set to be shortened at a constant ratio as described above. Even at the time of drawing, uniform exposure with a certain dose amount can be ensured. As a result, the photosensitive shape becomes predetermined with the accuracy of the drawing shape, and the signal quality can be improved.

  In the above embodiment, the beam scanning of the element 3 is performed by XY deflection that deflects in the radial direction Y while irradiating the electron beam EB, and reciprocally vibrates at a constant amplitude in the circumferential direction X. The beam operation may be performed by XY deflection in which the reciprocal vibration direction is the radial direction Y and the deflection is performed in the circumferential direction X. In that case, a triangular wave deflection signal similar to the above is output as the deflection control signal in the circumferential direction X, and the triangular wave correction in the first or second drawing method similar to the above is performed. In addition, the accuracy of the drawing shape accompanying the rounding of the triangular wave can be improved.

<Electron beam drawing device>
An embodiment of an electron beam drawing apparatus for carrying out the above-described electron beam drawing method of the present invention will be described. FIG. 6 is a schematic configuration diagram of an electron beam drawing apparatus.

  The electron beam drawing apparatus 100 includes an electron beam irradiation unit 20 that irradiates the master with an electron beam, a drive unit 30 that rotates and linearly moves the master, and a drive control unit 40 that performs mechanical drive control in the drive unit 30. And a formatter 50 that generates a drawing clock and outputs operation timing signals of the electron beam irradiation unit 20 and the drive unit 30, and a data sending device 5 that sends design data related to a pattern to be drawn to the formatter 50. ing. In addition, the electron beam drawing apparatus 100 has the above-described triangular wave correction function.

  The electron beam irradiation unit 20 deflects the electron gun 21 that emits the electron beam EB into the lens barrel 18, deflects the electron beam EB in the radial direction Y and the circumferential direction X, and performs minute reciprocating vibration in the circumferential direction X with a constant amplitude. Means 22 and 23 are provided with an aperture 25 and a blanking 26 (deflector) as blanking means 24 for on / off control of irradiation of the electron beam EB, and the electron beam EB emitted from the electron gun 21 is deflected. The light is irradiated onto the master (here, the substrate 10 coated with the resist 11) through the means 22, 23 and an electromagnetic lens (not shown).

  The aperture 25 in the blanking means 24 has a through-hole through which the electron beam EB passes in the center, and the blanking 26 is accompanied by the input of an on / off signal (the blanking signal BLK), and the electron beam at the time of the off signal. The beam is irradiated through the aperture 25 without deflecting the EB, while the electron beam EB is deflected and blocked by the aperture 25 without passing through the aperture 25 in the ON signal. It operates so as not to irradiate EB.

  The drive unit 30 includes a rotary stage 31 that supports the master in a casing 19 with the lens barrel 18 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 and the linear moving means 34 for linearly moving the rotary stage unit 33 in one radial direction of the rotary stage 31 are provided. 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 generator 51 that generates an invariant reference clock, a drawing clock generator 52 that generates a drawing clock, and deflection means 22 and 23 for the electron beam irradiation unit 20 based on the drawing clock. In response to a signal from the encoder 37, a data distribution unit 54 for sending a data signal to a deflection amplifier 28 and a blanking amplifier 29 for the blanking 26 and a PLL circuit connected to the driver 41 of the spindle motor 32, A timing control unit 55 that controls operation timing (data distribution timing) is provided.

  The drawing clock generation unit 52 includes a changing unit 56 for changing the drawing clock frequency according to the radial position of the master, and the number N of drawing clocks for drawing one element is set to be the same on the inner and outer circumferences. In addition, when performing the triangular wave correction in the second drawing method, the changing unit 56 performs a change to reduce and correct the same clock number Δn on the inner and outer circumferences from the drawing clock number N.

  The data transmission device 5 stores drawing design data (data indicating a drawing pattern and drawing timing) of a desired pattern to be drawn, such as a hard disk pattern, and sends a drawing design data signal to the formatter 50.

  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 electronic data by the on / off control of the blanking means 24 and the deflection means 22 and 23. The control signals are distributed to the amplifiers 28 and 29 and the drivers 41 and 42 as control signals for XY deflection control of the beam EB, rotation speed control of the rotary stage 31, and the control signals are input from the encoder 37. It is sent at a predetermined timing (for example, the above-mentioned points a and b) in synchronization with the signal. 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 on the entire surface of the master.

  The blanking amplifier 29 for the blanking 26 for the blanking means 24 is provided with a delay circuit 57. The delay circuit 57 is a blanking signal in the triangular wave correction in the first and second drawing methods described above. The output of the on / off signal to the blanking 26 is delayed based on the delay times d2 to d4 set to.

  Further, the formatter 50 outputs the Y-direction deflection signal Def (Y) and the unillustrated X-direction deflection signal Def (X) based on the triangular wave deflection signals to the deflection means 22 and 23. 4B, the amplitudes V2 and V3 of the triangular wave deflection signal corrected in accordance with the delay amount of the on / off signal to the blanking 26 and the shortening ratio of the beam irradiation time set in FIG. ) Or a deflection signal as shown in FIG.

  Next, FIG. 7 shows a case where a fine uneven pattern is transferred to a magnetic disk medium using an imprint mold 70 having a fine pattern drawn by the above-described 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. 7) is applied to the surface of a substrate 71 made of a translucent material, and the servo pattern 12 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 and a groove pattern 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. 8 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. The desired pattern 12 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.

  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. 8A, an initial direct current magnetic field Hin is applied in advance to the magnetic disk medium 85 in one direction perpendicular to the track surface to cause the magnetic recording layer 87 to undergo initial direct current magnetization. Thereafter, as shown in FIG. 8B, the surface of the magnetic disk medium 85 on the recording layer 87 side 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. The 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 the reversal of the magnetization of the other portions, a magnetization pattern corresponding to the uneven 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 transmission apparatus 10 Board | substrate 11 Resist 12 Servo pattern 13 Servo element 15 Data area 18 Lens barrel 20 Electron beam irradiation part 21 Electron gun 22, 23 Deflection means 24 Blanking means 25 Aperture 26 Blanking 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 55 Timing control unit 56 Change unit 57 Delay circuit 70 Imprint mold 80, 85 Magnetic disk medium 90 Master carrier 100 Electron beam drawing device

Claims (12)

About irradiating an electron beam corresponding to a drawing shape while rotating the rotary stage on a substrate coated with a resist and placed on the rotary stage.
While controlling the irradiation timing of the electron beam by the output of an on / off signal to the blanking means for blocking the electron beam irradiation,
In the electron beam drawing method of scanning and drawing the electron beam so as to fill the element shape of the fine pattern by controlling the deflection operation of the electron beam by outputting a triangular wave deflection signal to the beam deflecting means,
With respect to a reference drawing time assigned for drawing the element, electron beam irradiation is started by the turning-off operation of the blanking means, and the beam irradiation time for ending the electron beam irradiation by the on-operation is shortened. Set the on / off signal,
The amplitude of the triangular wave deflection signal with respect to the beam deflection means is set to be large in inverse proportion to the shortening ratio of the beam irradiation time with respect to the reference amplitude of the triangular wave deflection signal required to draw the element,
Further, the output timing of the on / off signal to the blanking means is set so that the beam irradiation time is located within the operation period in which the electron beam is deflected based on the triangular wave deflection signal output to the beam deflecting means. An electron beam drawing method comprising:   The shortening of the beam irradiation time in the blanking means is based on the output timing of the on signal for ending the electron beam irradiation based on the delay amount of the output timing of the off signal for starting the electron beam irradiation with respect to the reference drawing time. 2. The electron beam writing method according to claim 1, wherein the delay amount is set to be small.   2. The electron beam writing method according to claim 1, wherein the beam irradiation time in the blanking means is shortened by subtracting an integer number of clocks of a drawing clock signal corresponding to the reference drawing time.   The shortening of the beam irradiation time in the blanking means subtracts the number of clocks of the irradiation start point and irradiation end point of the drawing clock signal corresponding to the reference drawing time, delays the irradiation start point, and accelerates the irradiation end point. 4. The electron beam writing method according to claim 3, wherein the setting is performed as described above. 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 on / off signal for the blanking means and the triangular wave deflection signal for the beam deflecting means are created based on a drawing clock signal generated in conjunction with rotation of the rotary stage, and the drawing clock signal is 5. The electron beam writing method according to claim 3, wherein the number of clocks in one rotation of the rotary stage is a constant value regardless of the radius of the drawing position.   While rotating the substrate in one direction, the electron beam is vibrated minutely in the radial direction of the substrate or in a direction orthogonal to the radial direction, and deflected in the direction orthogonal to the vibration direction based on the triangular wave deflection signal. 6. The electron beam drawing method according to claim 1, wherein the element is drawn. In order to realize the electron beam drawing method according to any one of claims 1 to 6,
A rotating stage that rotates the substrate coated with the resist, a blanking unit that blocks irradiation of the electron beam emitted from the electron gun, a beam deflecting unit that deflects and scans the electron beam, and the blank based on the drawing data signal. An electron beam drawing apparatus comprising: a formatter for outputting an on / off signal for a ranking means and a triangular wave deflection signal for the beam deflection means.   The blanking means determines the output timing of the on signal for ending the irradiation of the electron beam from the delay amount of the output timing of the off signal for starting the irradiation of the electron beam in the on / off signal to the blanking means. 8. The electron beam drawing apparatus according to claim 7, further comprising a delay circuit that sets the delay amount to be small and shortens the beam irradiation time.   8. The electron beam according to claim 7, wherein the formatter reduces the beam irradiation time for the blanking means by subtracting an integer number of clocks of a drawing clock signal corresponding to a reference drawing time. Drawing device   A step of drawing a desired fine pattern on the substrate coated with a resist by the electron beam drawing method according to any one of claims 1 to 6, and forming an uneven pattern corresponding to the desired fine pattern. A method for manufacturing a mold, characterized by being manufactured through a process.   A step of drawing a desired fine pattern on the substrate coated with a resist by the electron beam drawing method according to any one of claims 1 to 6, and forming an uneven pattern corresponding to the desired fine pattern. A method for producing a magnetic disk medium, comprising: using an imprint mold produced through the transfer, and transferring a concavo-convex pattern corresponding to the concavo-convex pattern provided on the surface of the mold.   A step of drawing a desired fine pattern on the substrate coated with a resist by the electron beam drawing method according to any one of claims 1 to 6, and forming an uneven pattern corresponding to the desired fine pattern. A method for producing a magnetic disk medium, comprising: using a magnetic transfer master carrier produced through the magnetic transfer, and magnetically transferring a magnetization pattern corresponding to the concavo-convex pattern provided on the surface of the master carrier.

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