JP2009223155A - Electron beam drawing method, electron beam drawing device, uneven pattern carrier, and magnetic disk medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To draw concentric patterns on a drawing object with high accuracy by simple control. <P>SOLUTION: An electron beam drawing method comprises irradiating a drawing object mounted on a rotation stage 41 equipped with a rotary encoder 53 with an electron beam so as to draw concentric patterns while rotating the rotation stage 41. In the method, the following steps are repeated to draw the concentric patterns. The steps are: after a pattern along a predetermined concentric circle is drawn, turning off the electron beam irradiation by a specified encoder pulse; deflecting an irradiation position of the electron beam by a track pitch in a radial direction while the electron beam irradiation is stopped; then turning on the electron beam irradiation by a specified encoder pulse generated when the rotation stage 41 makes one revolution after the electron beam irradiation is turned off, so as to start to draw a pattern along a concentric circle adjacent to the predetermined concentric circle; and turning off the electron beam irradiation by a specified encoder pulse generated when the rotation stage makes one revolution after starting to draw. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention provides an electronic device for drawing a pattern corresponding to a desired concavo-convex pattern when producing 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, or the like. The present invention relates to a beam drawing method and an electron beam drawing apparatus.

  The present invention also provides a concavo-convex pattern carrier comprising an imprint mold having a concavo-convex pattern surface or a master carrier for magnetic transfer, which is produced through a drawing process using the electron beam drawing method, and the concavo-convex pattern. The present invention relates to a magnetic disk medium having a concavo-convex pattern transferred using an imprint mold as a pattern carrier and a magnetic disk medium having a magnetized pattern transferred using a magnetic transfer master carrier.

  Current magnetic disk media generally employ a concentric track arrangement, and information patterns such as servo patterns are formed along concentric tracks. 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. Here, the grooves provided between the data tracks are also formed concentrically. 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, an electron beam recording apparatus for patterning a predetermined high-density pattern such as a servo pattern on a master disk of a magnetic transfer master carrier for manufacturing a high-density magnetic disk medium has been proposed.

  When drawing a concentric pattern, there is a problem in the feeding method when sending the electron beam to an adjacent track (adjacent concentric circle). After drawing one concentric circle, a method of drawing the adjacent track by moving the rotary stage in the radial direction is also conceivable. However, every time one track is drawn, it is moved by the track pitch to stabilize the rotation. There is a problem that it takes a very long time to draw the track.

  A method for forming a concentric track pattern for solving such a problem has been proposed in Patent Document 1, Non-Patent Document 1, and the like.

Non-Patent Document 1 and Patent Document 1 relate to high-density patterning using an electron beam recording apparatus. During one rotation, the rotation stage is controlled to move by one track pitch in the radial direction, and simultaneously performs one rotation. By gradually deflecting the beam in the radial direction by one track pitch, drawing for one rotation, connecting the start point and end point of the circle, drawing one track, then deflecting the electron beam at high speed, the outer track A method of shifting to drawing is disclosed.
JP 2002-367241 A PIONNER R & D Vol.14 No.1 p.1-8 “High-density patterning using electron beam recorder”

  Although there is no clear description in Non-Patent Document 1 and Patent Document 1, in these conventional concentric track drawing methods, a single encoder pulse out of encoder pulses generated during one rotation is used as a reference. It is considered that control is performed so as to shift from drawing a track to drawing the next track.

  FIG. 9 is a timing chart of control signals considered to have been conventionally performed, and FIG. 10 is a diagram for explaining concentric circles drawn by track feed by this control. 9A shows the rotation of the stage, FIG. 9B shows the encoder pulse, FIG. 9C shows the beam deflection, and FIGS. 9D and 9E show the methods of Non-Patent Document 1 and Patent Document 1, respectively. This shows the timing of electron beam irradiation on / off. FIG. 10 (A) shows the track feed position at the time of concentric drawing, and FIGS. 10 (B) and 10 (C) show the tracks when the electron beam irradiation is turned on / off by the method of Non-Patent Document 1 and Patent Document 1, respectively. The drawing trajectory at the feed position is shown.

  As shown in FIG. 10A, when drawing a concentric circle, drawing is started at a predetermined angular position, drawing is completed once at a predetermined angular position, and the drawing position is placed on the next track (concentric circle). To start drawing the next track.

More specifically, as shown in FIG. 9, the drawing of the track 1 (Tr ₁ ) starts with the encoder pulse z as a starting point, ends with the same encoder pulse z counted after one rotation as an end point, and further this pulse. Starting from z, the beam is deflected to the adjacent track 2 (Tr ₂ ) and drawing of Tr ₂ is started. Similarly, the drawing of Tr ₂ is finished by the encoder pulse z and the drawing of Tr ₃ is started.

  At this time, in the method of Non-Patent Document 1, the electron beam irradiation is always turned on as shown in FIG. For this reason, since the electron beam irradiation is continued even when the beam is moved to the adjacent track, as shown in FIG. 10B, the exposure locus is connected to the adjacent track at the deflection position.

On the other hand, in the method of Patent Document 1, as shown in FIG. 9 (E), the electron beam irradiation is turned off starting from the encoder pulse z, and the electron beam irradiation is turned off when the beam is deflected. There is no connection with the track to be. However, since the rotary stage continues to rotate, when the beam is moved in the radial direction, the drawing start position of Tr ₂ is slightly shifted in the circumferential direction as shown in FIG. Due to this shift, if the Tr ₂ drawing is completed with the next encoder pulse z, there is a problem that the track and the track are not completely connected and the track is interrupted.

  In the methods of Patent Document 1 and Non-Patent Document 1, since it is necessary to synchronize one rotation of the rotary stage and linear movement in the radial direction, and further, deflection of the beam, complicated control is performed. Must-have.

  SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides an electron beam drawing method that does not cause a joint between adjacent concentric circles (tracks) or a break in one concentric pattern when drawing a concentric pattern, and The object is to provide an apparatus.

  The present invention also provides a concavo-convex pattern carrier such as an imprint mold or a magnetic transfer master carrier having a pattern drawn with high precision by an electron beam, and a concavo-convex pattern using the concavo-convex pattern carrier. Alternatively, it is an object to provide a magnetic disk medium to which a magnetic pattern is transferred.

The first electron beam drawing method of the present invention irradiates an electron beam onto a drawing object placed on a rotary stage equipped with a rotary encoder, and draws a concentric pattern while rotating the rotary stage. In the electron beam drawing method,
After drawing a pattern along a predetermined concentric circle, turn off the electron beam irradiation with a specific encoder pulse,
This occurs when the electron beam irradiation position is turned off and the electron beam irradiation position is deflected in the radial direction by the track pitch, and then the electron beam irradiation is turned off and then the rotation stage makes one rotation. The electron beam irradiation is turned on with the specific encoder pulse to start drawing a pattern along a concentric circle adjacent to the predetermined concentric circle, and the specific stage generated when the rotary stage makes one rotation from the start of the drawing. The process of turning off the irradiation of the electron beam with an encoder pulse is repeated to draw a concentric pattern.

  The “concentric circle adjacent to the predetermined concentric circle” is a concentric circle having a one track pitch radius larger or smaller than the predetermined concentric circle. Further, here, by drawing a concentric pattern, a concentric track is drawn as a result.

In the second electron beam writing method of the present invention, a concentric pattern is formed while irradiating an electron beam onto an object to be drawn placed on a rotary stage equipped with a rotary encoder and rotating the rotary stage. In the electron beam drawing method for drawing,
After drawing a pattern along a predetermined concentric circle, the electron beam irradiation is turned off with the first encoder pulse,
With the electron beam irradiation turned off, the irradiation position of the electron beam is deflected in the radial direction by the track pitch, and then the second encoder pulse different from the first encoder pulse is used. Irradiation is turned on, drawing of a pattern along a concentric circle adjacent to the predetermined concentric circle is started, and irradiation of the electron beam is performed with the second encoder pulse generated when the rotary stage makes one rotation from the start of the drawing. A concentric pattern is drawn by repeating the step of turning off.

  In the second electron beam writing method of the present invention, it is particularly preferable that the second encoder pulse is an encoder pulse generated immediately after deflecting the electron beam.

A first electron beam drawing apparatus of the present invention is an apparatus capable of performing the first electron beam drawing method of the present invention, and includes a rotary stage having a rotary encoder on which a drawing object is placed, An electron gun that emits an electron beam for drawing a concentric pattern on the drawing object, and an irradiation position of the electron beam emitted from the electron gun in the radial direction of the concentric circle on the drawing object An electron beam drawing apparatus comprising: deflection means for deflecting; blanking means for turning on and off the electron beam irradiation to the drawing object; and a controller for controlling the operation of each means in association with each other;
After the controller draws a pattern along a predetermined concentric circle, the controller controls the blanking means with a specific encoder pulse from the rotary encoder as a starting point to turn off the irradiation of the electron beam, and the deflection means The control unit deflects the irradiation position of the electron beam by the track pitch in the radial direction, and starts the specific encoder pulse generated when the rotary stage makes one rotation from the time when the irradiation of the electron beam is turned off. The irradiation of the electron beam is turned on to start drawing a pattern along a track adjacent to the predetermined track, and the electron is generated by the specific encoder pulse generated when the rotary stage makes one rotation from the start of the drawing. The blanking means is controlled to turn off the beam irradiation. To.

A second electron beam drawing apparatus of the present invention is an apparatus capable of performing the second electron beam drawing method of the present invention, and includes a rotary stage having a rotary encoder on which an object to be drawn is placed, An electron gun that emits an electron beam for drawing a concentric pattern on the drawing object, and an irradiation position of the electron beam emitted from the electron gun in the radial direction of the concentric circle on the drawing object An electron beam drawing apparatus comprising: deflection means for deflecting; blanking means for turning on and off the electron beam irradiation to the drawing object; and a controller for controlling the operation of each means in association with each other;
After the controller draws a pattern along a predetermined concentric circle, the blanking means is controlled from the first encoder pulse from the rotary encoder as a starting point to turn off the irradiation of the electron beam, and the deflection means And the electron beam irradiation position is turned on starting from a second encoder pulse different from the first encoder pulse, after deflecting the irradiation position of the electron beam by the track pitch in the radial direction. The blanking is started so that the drawing of the track adjacent to the predetermined track is started, and the irradiation of the electron beam is turned off by the second encoder pulse generated when the rotary stage makes one rotation from the start of the drawing. It is characterized by controlling the means.

  It is particularly desirable that the second encoder pulse is set to an encoder pulse generated immediately after deflecting the electron beam.

  The concavo-convex pattern carrier of the present invention draws and exposes a concentric desired pattern on the resist coated on the substrate by the electron beam drawing method according to any one of claims 1 to 3, thereby forming the desired pattern. It is produced through a process of forming a corresponding uneven pattern. Here, the concavo-convex pattern carrier is a carrier having a desired concavo-convex pattern shape on the surface, an imprint mold for transferring the concavo-convex pattern shape to a transfer medium, and a magnetized pattern corresponding to the concavo-convex pattern shape. For example, a magnetic transfer master carrier for transferring to a transfer medium.

  A magnetic disk medium according to the present invention draws and exposes a concentric desired pattern on a resist coated on a substrate by the electron beam drawing method according to any one of claims 1 to 3, and according to the desired pattern. The concavo-convex pattern corresponding to the concavo-convex pattern provided on the surface of the mold is transferred using an imprint mold produced through the step of forming the concavo-convex pattern. Specific examples include discrete track media and bit pattern media.

  A magnetic disk medium according to the present invention draws and exposes a concentric desired pattern on a resist coated on a substrate by the electron beam drawing method according to any one of claims 1 to 3, and according to the desired pattern. Using a magnetic transfer master carrier produced through a step of forming a concave / convex pattern, and a magnetic pattern corresponding to the concave / convex pattern provided on the surface of the master carrier is magnetically transferred. is there.

  According to the first electron beam writing method and apparatus of the present invention, after drawing a pattern along a predetermined concentric circle, the electron beam irradiation is turned off at a specific encoder pulse, and the electron beam irradiation is turned off. After the electron beam irradiation position is deflected in the radial direction by the track pitch, the electron beam irradiation is turned on with a specific encoder pulse generated when the rotation stage rotates once after the electron beam irradiation is turned off. A concentric pattern is formed by repeating drawing a pattern along a concentric circle adjacent to the concentric circle and turning off the irradiation of the electron beam with a specific encoder pulse generated when the rotary stage makes one rotation from the start of the drawing. So that adjacent concentric circles are not connected, and one concentric pattern is drawn accurately without interruption. It can be. Further, since there is no movement of the stage at the time of drawing, the complicated control of synchronizing the rotation of the stage and the linear movement as described in Patent Document 1 and Non-Patent Document 1 is not required.

  According to the second electron beam writing method and apparatus of the present invention, after drawing a pattern along a predetermined concentric circle, the electron beam irradiation is turned off by the first encoder pulse, and the electron beam irradiation is turned off. Then, after the irradiation position of the electron beam is deflected by the track pitch in the radial direction, the irradiation of the electron beam is turned on with a second encoder pulse different from the first encoder pulse, and the track is adjacent to a predetermined track. Since the drawing of the pattern is started and the process of turning off the irradiation of the electron beam with the second encoder pulse generated when the rotation stage makes one rotation from the start of the drawing, the concentric pattern is drawn. The adjacent concentric circles are not connected, and one concentric pattern can be accurately drawn without being interrupted. Further, since there is no movement of the stage at the time of drawing, the complicated control of synchronizing the rotation of the stage and the linear movement as described in Patent Document 1 and Non-Patent Document 1 is not required.

  Embodiments of the present invention will be described below.

  An electron beam drawing system 20 shown in FIG. 1 includes an electron beam drawing apparatus 40 and a signal transmission apparatus 60 according to an embodiment of the present invention. The electron beam drawing apparatus 40 includes a rotary stage 41 that supports a drawing object 11 in which an electron beam resist 11b is coated on a substrate 11a, and a motor shaft provided so as to coincide with a central axis 42 of the stage 41. A rotary stage unit 45 having a spindle motor 44 having a shaft, a shaft 46 that passes through a part of the rotary stage unit 45 and extends in one radial direction of the rotary stage 41 (in the direction of arrow Y in the figure), Linear movement means 49 for moving the rotary stage unit 45 along the shaft 46 is provided. A part of the rotary stage unit 45 is screwed with a precise threaded rod 47 arranged in parallel with the shaft 46 so that the rod 47 is rotated forward and backward by a pulse motor 48. The rod 47 and the pulse motor 48 constitute a linear moving means 49 of the rotary stage unit 45. In order to detect the rotation of the rotary stage 41, an encoder 53 is installed which generates encoder pulses at regular intervals with a predetermined rotational phase by reading the encoder slit, and this encoder pulse signal is sent to the controller 50. The controller 50 drives the spindle motor 44, that is, the rotational speed of the rotary stage 41, drives the pulse motor 48, that is, moves linearly by the linear moving means 49, modulates the electron beam, controls the polarizing means 21 and 22, and blanking means 24. Control means for performing on / off control and the like of the blanking 26, and includes clock means (not shown) for generating a reference clock signal in timing control.

  Further, the electron beam drawing apparatus 40 includes an electron gun 23 that emits an electron beam, and polarization means 21 and 22 that polarize the electron beam EB in the Y direction (substrate radial direction) and the X direction (circumferential direction) orthogonal to the Y direction. Further, an aperture 25 and a blanking 26 (deflector) are provided as blanking means 24 for turning on / off the irradiation of the electron beam EB, and the electron beam EB emitted from the electron gun 23 is deflected by the deflecting means 21, 22 and The object 11 is irradiated through a 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 has an aperture without deflecting the electron beam EB when the on signal is input in response to the input of the on / off signal. On the other hand, at the time of an off signal, the electron beam EB is deflected and blocked by the aperture 25 without passing through the aperture 25 so that the electron beam EB is not irradiated. Operate.

  The signal sending device 60 stores drawing data of a desired fine pattern to be drawn on the drawing object, and sends the drawing data signal to the controller 50. The controller 50 is based on the drawing data signal. Such linkage control is performed, and a desired fine pattern is drawn on the entire surface of the drawing object by the electron beam drawing apparatus 40.

An embodiment of the first electron beam drawing method of the present invention using the above-described electron beam drawing apparatus 40 will be described with reference to the timing chart shown in FIG. 2A shows the rotation of the stage 41, FIG. 2B shows the encoder pulse, FIG. 2C shows the beam deflection (beam irradiation position), and FIG. 2D shows the electron beam irradiation on / off by the blanking means 24. It shows the off timing. As shown in FIG. 2, the drawing of the track 1 (Tr ₁ ) starts with a predetermined encoder pulse z as a starting point, and ends with the same encoder pulse z counted after one rotation as an end point. The encoder pulse z is a pulse counted at a specific angular position once during one rotation of the rotary stage. In FIG. 2B, n in z (n) is a number indicating the number of rotations of the stage from the drawing start given for convenience of explanation.

Drawing start of the track 1 (Tr ₁ ) starts with the encoder pulse z (1), and ends when the beam is turned off by the blanking means 24 with the next encoder pulse z (2). At the same time, starting from the encoder pulse z (2), the beam irradiation position is deflected by one track pitch in the radial direction (Y direction) by the deflecting means 21. After the encoder pulse z (2), the rotary stage 41 makes one rotation while the beam is off, and the beam is turned on by the blanking means 21 from the encoder pulse z (3) as a starting point to the track 1 (Tr ₁ ). Drawing of adjacent track 2 (Tr ₂ ) is started. Thereafter, the concentric circle of the track 2 is drawn with the rotation of the rotary stage until the encoder pulse z (4) is detected again. The beam is turned off again by the blanking means 24 at the encoder pulse z (4), and at the same time, the beam is further deflected by one track pitch in the radial direction. A plurality of concentric circles are drawn by repeating this procedure. In this drawing method, drawing start positions and end positions of all concentric circles are determined starting from a specific encoder pulse z, and one concentric circle is drawn by rotating the stage twice. According to this method, the connection between the tracks and the concentric circles having no jump in the pattern in one track can be drawn with high accuracy, and the control performed by the controller becomes very simple.

  Here, the drawing of the track is synonymous with the drawing of the concentric pattern, and in reality, the drawing of the pattern results in the formation of the concentric track.

  In the above process, the deflection of the beam irradiation position in the radial direction is performed by the deflection means 21, but generally the deflection distance in the radial direction by the deflection means 21 is limited. Accordingly, the deflection is repeated by one track pitch, and after the limit of the deflection in the radial direction by the deflection means 21 is reached (for example, after concentric circles for 8 tracks are drawn), the deflection of the beam in the radial direction by the deflection means 21 is performed. And a step of moving the rotary stage in the radial direction by about 8 tracks using the linear moving means 49 is required.

  In this way, the process of sequentially drawing a plurality of concentric tracks by beam deflection by the deflecting means 21 and the process of moving the rotary stage 41 are repeated to draw the concentric tracks from the innermost circumference to the outermost circumference.

  The controller 50 of the electron beam drawing apparatus 40 according to the first embodiment controls the blanking means 24 using a specific encoder pulse from the rotary encoder 53 as a starting point to perform the drawing method as described above. The beam irradiation is turned off and the deflecting means 21 is controlled to deflect the electron beam irradiation position by the track pitch in the radial direction, and the rotary stage 41 has made one rotation from the time when the electron beam irradiation is turned off. With the specific encoder pulse generated at the beginning, the irradiation of the electron beam is turned on and drawing of the track adjacent to the predetermined track is started, and the specific encoder pulse generated when the rotation stage 41 makes one rotation from the start of the drawing The blanking means 24 is controlled to turn off the electron beam irradiation. Further, the beam is once turned off by the blanking means every predetermined number of tracks (for example, 8 tracks), the rotary stage is moved in the radial direction by the linear moving means, and the beam deflection control by the deflecting means is temporarily reset. It is configured.

  Next, an embodiment of the second electron beam drawing method of the present invention using the electron beam drawing apparatus 40 of the second embodiment will be described with reference to the timing chart shown in FIG. Note that when the second electron beam drawing method is performed, the configuration of the controller 50 of the electron beam drawing apparatus 40 is different from that of the above embodiment, but this point will be described later.

3A shows the rotation of the stage 41, FIG. 3B shows the encoder pulse, FIG. 3C shows the beam deflection (beam irradiation position), and FIG. 3D shows the electron beam irradiation on / off by the blanking means 24. It shows the off timing. As shown in FIG. 3, the drawing of the track 1 (Tr ₁₎ is started first encoder pulses A ₁ as a starting point to end the same encoder pulse A ₁ counted after one revolution as the end point. That is, the start of the drawing truck 1 (Tr ₁₎ starts with the encoder pulse A _1, beam blanking means 24 in one revolution encoder pulse A ₁ after ends by being turned off. At the same time, starting from this encoder pulse A ₁ , the beam irradiation position is deflected by one track pitch in the radial direction by the deflecting means 21. Next, with the encoder pulse A ₂ detected after the deflection of the beam by the deflecting means 21 as a starting point, the beam is turned on by the blanking means 24 and the track 2 (Tr ₂ ) adjacent to the track 1 (Tr ₁ ). ) Starts drawing. Thereafter, the track 2 is drawn with the rotation of the rotary stage until the encoder pulse A ₂ is detected again, and a concentric circle is drawn. Beam blanking means 24 in encoder pulses A ₂ is turned off again, at the same time the beam is a track pitch deflection further radially. By repeating this procedure, a plurality of concentric tracks are drawn. In this drawing method, when one concentric circle and an adjacent concentric circle are drawn, adjacent concentric circles are drawn using an encoder pulse different from an encoder pulse as a starting point and an ending point for drawing one concentric circle as starting and ending points. Therefore, the starting position (rotational angle position) of the concentric circle gradually shifts. Accordingly, the control is complicated compared to the first embodiment in which the drawing start and end points are controlled by a specific encoder pulse, but drawing of the next track is started before the stage makes two rotations. The entire drawing can be performed in a shorter time than in the case of the embodiment.

  As in the case of the first embodiment, the deflection of the beam irradiation position in the radial direction is performed by the deflection unit 21 and the deflection is repeated by one track pitch, and the limit of the deflection in the radial direction by the deflection unit is reached. Later (for example, after drawing concentric circles for 10 tracks), the step of once releasing the deflection of the beam in the radial direction by the deflecting means and moving the rotary stage in the radial direction by about 10 tracks using the linear moving means. Cost.

  In this way, the step of sequentially drawing a plurality of concentric tracks by the deflection by the deflecting means and the step of moving the rotary stage are repeated to draw a desired number of concentric tracks from the innermost circumference to the outermost circumference.

In order to carry out the electron beam drawing method of the second embodiment, the controller 50 of the electron beam drawing apparatus 40 controls the blanking means 24 using the first encoder pulse A ₁ from the rotary encoder 53 as a starting point to control the electron beam drawing method. The beam irradiation is turned off and the deflecting means 21 is controlled to deflect the electron beam irradiation position by the track pitch in the radial direction, and then the second encoder pulse different from the first encoder pulse is started. Then, the electron beam irradiation is turned on, drawing of a track adjacent to a predetermined track is started, and the irradiation of the electron beam is turned off by the second encoder pulse generated when the rotation stage 41 makes one rotation from the start of the drawing. Thus, the blanking means 24 is configured to be controlled. Further, the beam is once turned off by the blanking means 24 every predetermined number of tracks (for example, 10 tracks), the rotary stage 41 is moved in the radial direction by the linear moving means 49, and the deflection of the beam by the deflecting means is once in the initial state. Control is made to return to (the state in which the first track is drawn).

  Next, a manufacturing process for producing an imprint mold for a discrete track medium using the electron beam drawing method and apparatus of the present invention will be briefly described with reference to FIG.

  The drawing object 11 placed on the rotary stage 41 is obtained by coating a negative electron beam drawing resist 11b on the surface of a substrate 11a made of, for example, silicon, glass, or quartz.

  For example, a concentric pattern is drawn on the resist 11b by using the drawing method of the first embodiment described above, and concentric grooves 15 are drawn here. Practically, if a servo pattern is drawn in the servo area and a groove is drawn in the data area, the servo signal can be transferred at the same time. However, there is also a demand for a drawing in which only concentric grooves are drawn. A case of drawing will be described.

  The controller 50 controls the drawing method of the first embodiment described above and draws the concentric groove 15 (FIG. 4A). Drawing of the groove 15 along the track is sequentially performed from the outermost track side to the innermost track side, and concentric tracks over the entire region are drawn as shown in FIG. With the drawing method of this embodiment, concentric circles that are not connected to adjacent tracks during track feeding and in which unnecessary jumps do not occur in one track can be drawn.

It is desirable to adjust the output of the electron beam EB and the beam diameter in consideration of the groove width and the sensitivity of the electron beam writing resist.

  Next, the resist is developed to obtain a substrate having a desired pattern transferred to the resist. The substrate is etched using the patterned resist as a mask, and then the resist is removed to obtain an imprint mold having a concavo-convex pattern on the surface.

  When a positive electron beam drawing resist is used as the resist, an imprint mold is obtained by electroforming or the like using an object to be drawn having a concavo-convex pattern on the surface obtained by removing the resist as a master.

  FIG. 5 is a schematic cross-sectional view showing a process of forming a discrete track medium 80 by transferring and forming a fine pattern using the imprint mold 70 having the fine pattern drawn by the electron beam drawing method.

  As described above, the imprint mold 70 is provided with the fine concavo-convex pattern 72 on which the concentric grooves 15 are drawn, and then processed through development, etching, and the like.

  An example of producing the magnetic recording medium 80 by the imprint method using the imprint mold 70 will be described. The magnetic recording 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 concave / convex fine pattern 72 of the imprint mold 70 is pressed against the resist resin layer 83, and the resist resin layer 83 is cured by ultraviolet irradiation, whereby the concave / convex 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, whereby the magnetic recording medium 80 for discrete track media in which a fine pattern is formed by the magnetic layer 82 can be manufactured.

A discrete track medium 80 obtained in this manner is shown in FIG. As shown in FIG. 6, the discrete track medium 80 has a concentric groove 15 formed therein. For example, SiO ₂ is embedded in the groove 15.

  When the servo pattern is drawn together with the groove, the servo pattern area needs to be drawn by modulating the electron beam in order to draw the servo pattern. As a servo signal drawing method, for example, a drawing method described in Japanese Patent Application Laid-Open No. 2004-158287 can be employed.

  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.

  Next, a method for manufacturing a magnetic transfer master carrier using the above-described electron beam drawing apparatus 40 and a method for manufacturing a magnetic recording medium by magnetic transfer using the magnetic transfer master carrier will be briefly described. FIG. 7 is a perspective view showing a drawing object 11 after drawing, which becomes a master disk of a magnetic transfer master carrier, and FIG. 8 is a schematic cross-sectional view showing an example of a basic process of the magnetic transfer.

  The production process of the master carrier is almost the same as the production method of the imprint mold. An object to be drawn 11 installed on the rotary stage is obtained by coating a negative electron beam drawing resist 11b on the surface of a substrate 11a made of, for example, silicon, glass, or quartz. A desired pattern 16 is drawn for each track by scanning a correspondingly modulated electron beam. The track feeding to the adjacent track is performed by the drawing method of the first or second embodiment described above, and the servo pattern 16 is drawn on each track by, for example, the drawing method described in Japanese Patent Application Laid-Open No. 2004-158287. . Note that concentric circles indicated by dotted lines in FIG. 7 schematically show concentric tracks, not actual drawn patterns.

  Thereafter, the electron beam lithography resist is developed to obtain a substrate on which the pattern along the concentric circle is transferred to the electron beam lithography resist. This is the master disk for the magnetic transfer master carrier.

  Next, a thin conductive layer is formed on the concave / convex pattern surface of the master, and electroforming is performed thereon to obtain a substrate 91 having a positive concave / convex pattern taking a metal mold. Thereafter, the substrate 91 having a predetermined thickness from the master 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 transfer master carrier 90 is obtained by coating the concave / convex pattern of the substrate with the magnetic layer 92. 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.

  Next, a magnetic transfer method using the magnetic transfer master carrier manufactured as described above will be described.

  A magnetic disk medium 85 to which information is transferred by magnetic transfer using a magnetic transfer master carrier is, for example, a disk-shaped magnetic recording medium such as a hard disk or a flexible disk in which a magnetic recording layer 87 is formed on both surfaces or one surface of a substrate 86. Here, a perpendicular magnetic recording medium in which the easy magnetization direction of the magnetic recording layer is formed in a direction perpendicular to the recording surface is used.

  FIG. 8 is a diagram for explaining the basic process of magnetic transfer. FIG. 8 (A) is a process of applying a magnetic field in one direction to initially magnetize a magnetic disk medium, and (B) is a master carrier. (C) is a diagram showing a state after magnetic transfer, in which a magnetic disk medium is brought into close contact and a magnetic field is applied in a direction opposite to the initial DC magnetic field. In FIG. 8, only the lower recording layer 86 side of the magnetic disk medium 85 is shown.

  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 on the recording layer 87 side of the magnetic disk medium 85 and the surface on the soft magnetic layer 92 side of the master carrier 90 are brought into close contact with each other and perpendicular to the track surface of the magnetic disk medium 85. Magnetic transfer is performed by applying a transfer magnetic field Hdu in the opposite direction to the initial direct-current magnetic field Hin. As a result, as shown in FIG. 8C, 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 magnetic disk medium 85. Here, the magnetic transfer by the master carrier 90 to the lower recording layer 87 of the magnetic disk medium 85 has been described. However, as shown in FIG. In close contact with the lower recording layer, magnetic transfer is performed simultaneously with the lower recording layer.

  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 pattern along a concentric circle using the electron beam writing method of the present invention is used. The manufacturing method is not limited to the above-described manufacturing method as long as it undergoes a process of drawing and forming an uneven pattern.

  The electron beam drawing method of the present invention is also effective in drawing a plurality of concentric circles with high accuracy when producing an optical element such as a Fresnel lens in which a plurality of concentric circles are formed on a transparent member.

It is the principal part side view (A) and partial top view (B) of the electron beam drawing system of one Embodiment which implements the electron beam drawing method of this invention. Timing chart of various control signals such as deflection signals in the electron beam writing method according to the first embodiment of the present invention Timing chart of various control signals such as deflection signals in the electron beam writing method according to the second embodiment of the present invention The figure which shows the drawing process of the groove pattern for discrete media Schematic sectional view showing a process of transferring and forming a fine pattern using the imprint mold of the present invention having a fine pattern drawn by an electron beam drawing method or a fine pattern drawing system Perspective view showing discrete media 80 The perspective view which shows the drawing pattern drawn on the original disk for master carriers for magnetic transfer (A) At the time of initial magnetic field application, (B) At the time of magnetic field application for transfer, (C) Sectional drawing which shows each magnetic transfer process after magnetic transfer Timing chart of various control signals such as deflection signals during conventional concentric pattern drawing (A) Schematic diagram showing track feed position at the time of conventional concentric circle drawing, (B) Enlarged view showing track drawing trajectory by track feeding method of conventional example 1, (C) Track drawing trajectory by track feeding method of conventional example 2 Enlarged view showing

Explanation of symbols

11 Drawing object
15 Groove pattern
EB Electron beam X Circumferential direction Y Disk radial direction
20 Electron beam drawing system
21, 22 Deflection means
23 electron gun
24 Blanking means
25 Aperture
26 Blanking
40 Electron beam lithography system
41 Rotating stage
44 Spindle motor
45 Rotating stage unit
49 Linear movement means
50 controller
53 Encoder
60 Signal transmitter
70 Imprint mold
71 Disc board
72 Fine uneven pattern
80 Magnetic recording media
81 board
82 Magnetic layer
83 Resist resin layer

Claims (9)

In an electron beam drawing method for irradiating an object to be drawn placed on a rotary stage equipped with a rotary encoder and drawing a concentric pattern while rotating the rotary stage,
After drawing a pattern along a predetermined concentric circle, turn off the electron beam irradiation with a specific encoder pulse,
This occurs when the electron beam irradiation position is turned off and the electron beam irradiation position is deflected in the radial direction by the track pitch, and then the electron beam irradiation is turned off and then the rotation stage makes one rotation. The electron beam irradiation is turned on with the specific encoder pulse to start drawing a pattern along a concentric circle adjacent to the predetermined concentric circle, and the specific stage generated when the rotary stage makes one rotation from the start of the drawing. An electron beam drawing method comprising: drawing a concentric pattern by repeating the step of turning off the irradiation of the electron beam with an encoder pulse. In an electron beam drawing method for irradiating an object to be drawn placed on a rotary stage equipped with a rotary encoder and drawing a concentric pattern while rotating the rotary stage,
After drawing a pattern along a predetermined concentric circle, the electron beam irradiation is turned off with the first encoder pulse,
With the electron beam irradiation turned off, the irradiation position of the electron beam is deflected in the radial direction by the track pitch, and then the second encoder pulse different from the first encoder pulse is used. Irradiation is turned on, drawing of a pattern along a concentric circle adjacent to the predetermined concentric circle is started, and irradiation of the electron beam is performed with the second encoder pulse generated when the rotary stage makes one rotation from the start of the drawing. An electron beam drawing method, wherein a concentric pattern is drawn by repeating the step of turning off.   3. The electron beam writing method according to claim 2, wherein the second encoder pulse is an encoder pulse generated immediately after deflecting the electron beam. A rotary stage having a rotary encoder on which an object to be drawn is placed, an electron gun that emits an electron beam for drawing a concentric pattern on the object to be drawn, and the electron gun emitted from the electron gun By the deflecting means for deflecting the irradiation position of the electron beam on the drawing object in the radial direction of the concentric circle, the blanking means for turning on / off the electron beam irradiation to the drawing object, and the respective means An electron beam lithography apparatus comprising a controller for controlling the operation in an associated manner,
After the controller draws a pattern along a predetermined concentric circle, the controller controls the blanking means with a specific encoder pulse from the rotary encoder as a starting point to turn off the irradiation of the electron beam, and the deflection means The control unit deflects the irradiation position of the electron beam by the track pitch in the radial direction, and starts the specific encoder pulse generated when the rotary stage makes one rotation from the time when the irradiation of the electron beam is turned off. The irradiation of the electron beam is turned on to start drawing a pattern along a concentric circle adjacent to the predetermined concentric circle, and the electron is generated by the specific encoder pulse generated when the rotary stage makes one rotation from the start of the drawing. The blanking means is controlled so that beam irradiation is turned off. That the electron beam lithography system. A rotary stage having a rotary encoder on which an object to be drawn is placed, an electron gun that emits an electron beam for drawing a concentric pattern on the object to be drawn, and the electron gun emitted from the electron gun By the deflecting means for deflecting the irradiation position of the electron beam on the drawing object in the radial direction of the concentric circle, the blanking means for turning on / off the electron beam irradiation to the drawing object, and the respective means An electron beam lithography apparatus comprising a controller for controlling the operation in an associated manner,
After the controller draws a pattern along a predetermined concentric circle, the blanking means is controlled from the first encoder pulse from the rotary encoder as a starting point to turn off the irradiation of the electron beam, and the deflection means And the electron beam irradiation position is turned on starting from a second encoder pulse different from the first encoder pulse, after deflecting the irradiation position of the electron beam by the track pitch in the radial direction. The drawing of the pattern along the concentric circle adjacent to the predetermined concentric circle is started, and the irradiation of the electron beam is turned off by the second encoder pulse generated when the rotary stage makes one rotation from the start of the drawing. And an electron beam lithography apparatus for controlling the blanking means.   6. The electron beam drawing apparatus according to claim 5, wherein the second encoder pulse is set to an encoder pulse generated immediately after the electron beam is deflected.   A process of drawing and exposing a concentric desired pattern on the resist applied on the substrate by the electron beam drawing method according to any one of claims 1 to 3, and forming a concavo-convex pattern according to the desired pattern. A concavo-convex pattern carrier characterized by being produced through the process.   A process of drawing and exposing a concentric desired pattern on the resist applied on the substrate by the electron beam drawing method according to any one of claims 1 to 3, and forming a concavo-convex pattern according to the desired pattern. A magnetic disk medium, wherein an uneven pattern corresponding to the uneven pattern provided on the surface of the mold is transferred using an imprint mold produced through the process.   A process of drawing and exposing a concentric desired pattern on the resist applied on the substrate by the electron beam drawing method according to any one of claims 1 to 3, and forming a concavo-convex pattern according to the desired pattern. A magnetic disk medium comprising: a magnetic transfer master carrier produced through magnetic transfer, and a magnetic pattern corresponding to the concavo-convex pattern provided on the surface of the master carrier being magnetically transferred.

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