JP2006156025A - Method and device for electron beam irradiation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for electron beam irradiation which do not require a large scale and complicated structure and can irradiate electron beams to a disc without deteriorating degree of vacuum in the electron beam column and in the space between an electron beam emitting aperture and the disc. <P>SOLUTION: The device for electron beam irradiation comprises a support section for supporting the disc and a head which has an opposed face to face the disc with a minute spacing. The head has the electron beam emitting aperture provided at the opposed face, an electron beam passage communicating with the electron beam emitting aperture, and one or more ring-shape gas suction channels opened at the opposed face. The electron beam passage and the ring-shape gas suction channels are respectively connected to a gas exhausting means, and the electron beam passage and the spacing between the electron beam emitting aperture and the disc are made vacuum. The support section operates to change the relative position relationship between the electron beam emitting aperture and the disc, thereby controls so that the electron beams may be irradiated from the outside to the inside of the disc in the order. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electron beam irradiation method and an electron beam irradiation apparatus used for producing a recording medium master.

  In recent years, various recording media such as optical discs, magneto-optical discs, phase change discs, and the like have been further increased in density, thereby enabling the fine formation of grooves such as data recording pits and track grooves on such recording media. It has been demanded. In addition, along with such miniaturization, there is a growing demand for the formation of a fine uneven pattern even when producing a master disk for these recording media.

  In the production of a recording medium master or the like, the resist layer coated and formed on the substrate is subjected to pattern exposure with laser light and developed to form a fine pattern on the resist layer, and nickel plating is applied thereon, for example, A stamper having a reversal pattern of a fine pattern, or a master stamper or a mother stamper for producing a stamper is formed.

  In such a method, for example, the recording pattern is exposed by modulating the laser beam with the recording signal and irradiating the laser beam spot while moving the laser beam spot relatively on the resist layer of the substrate. The laser light spot passes through the center of the substrate surface and rotates about a rotation axis perpendicular to the substrate surface, and shifts from the center of the substrate surface radially toward the outside of the substrate surface. Scan over the layer in a spiral or concentric circle.

  However, according to such an exposure method using laser light, there is a restriction on the spot diameter due to the optical limit depending on the laser wavelength, and a problem arises in the formation of a sufficient fine pattern. On the other hand, when exposure is performed using an electron beam, there is no such problem and finer patterning can be performed.

  However, the exposure using an electron beam requires work in a vacuum chamber so that the electron beam does not collide with gas molecules and scatter, and the apparatus becomes large. Further, the structure such as the above-described substrate rotation / transition drive mechanism and the vacuum seal of the signal wiring becomes complicated, resulting in an increase in the cost of the apparatus and the accompanying increase in the cost of the master and the recording medium.

  On the other hand, Patent Documents 1 and 2 propose an apparatus that can avoid the use of such a large vacuum chamber.

JP-A-11-288529

JP 11-328750 A

  In the devices proposed in Patent Document 1 and Patent Document 2, only the inside of an electron beam column in which an electron gun, a condenser electron lens, a deflecting means, a focus adjusting means, etc. are arranged in an electron optical column is evacuated. A diaphragm capable of transmitting an electron beam is provided so as to be held, and the electron beam is a space in which helium is supplied only in a short path of the beam between the electron beam column and the arrangement portion of the substrate having the resist layer. The arrangement part of the substrate, that is, its rotation, the transfer mechanism part, etc. is arranged in the atmosphere, so that the part kept at high vacuum can be reduced, and the apparatus can be simplified and simplified. It is intended to be illustrated.

  However, in the case of a configuration in which a part of the space is made into a vacuum chamber by the diaphragm, although the material and thickness of the diaphragm that are easy to transmit the electron beam are selected, the electron beam is scattered to some extent, Scattering also occurs when the electron beam collides with gas molecules in the space between this diaphragm and its electron beam irradiation surface (that is, the resist layer), and as a result, formation of a finer pattern is hindered. .

  Therefore, Patent Document 3 further proposes an electron beam irradiation apparatus that solves this problem.

JP 2001-24300 A

  The electron beam irradiation apparatus disclosed in Patent Document 3 is opposed to the electron beam irradiated body with a support portion that supports the electron beam irradiated body that is irradiated with the electron beam with a small interval. And an electron beam irradiation head having an electron beam emitting hole for irradiating the light. The electron beam irradiation head is provided with an electron beam passage communicating with the electron beam emission hole, and opens around the electron beam emission hole at a surface facing the electron beam irradiation object. One or more ring-shaped gas suction grooves are formed, and an exhaust unit, that is, a vacuum pump is connected to the electron beam passage and the ring-shaped gas suction grooves. With such a structure, the electron beam path is maintained at a high degree of vacuum.

  That is, this electron beam irradiation apparatus exhausts the electron beam passage communicating with the electron beam emission hole for the electron beam irradiated body and holds the electron beam passage in a vacuum. By providing a ring-shaped gas suction groove in the periphery, and by adopting a configuration that excludes gas in the vicinity of the minute gap between the electron beam irradiation head and the electron beam irradiated object, particularly the electron beam emission hole. The gas entering the electron beam emission hole and the gas in the space between the electron beam emission hole and the electron beam irradiated body are effectively excluded.

  In this manner, the electron beam path in the electron beam irradiation head can be maintained at a high vacuum, and the flight path led out from the electron beam emission hole and directed to the electron beam irradiation object can be maintained at a high vacuum. Therefore, it is possible to effectively avoid the scattering of the electron beam due to the above-described diaphragm and the scattering due to the collision with the gas molecules during the flight of the electron beam.

  When a recording medium having a fine concavo-convex pattern is produced using an electron beam irradiation apparatus as proposed in Patent Document 3 described above, the cutting is performed spirally from the inner side of the disk to the outer side (that is, the electron beam Irradiation). However, when high-speed rotation cutting is performed, the degree of vacuum in the electron beam column or in the space between the electron beam emission hole and the electron beam irradiated object is lowered, causing a problem that the electron gun is damaged.

  Further, as the substrate rotates at a higher speed, the jitter increases. For example, when creating a master disc of a Blu-ray disc ("BLU-RAY DISC" is a registered trademark), this jitter is set to a value within the Blu-ray disc standard. It becomes difficult to do.

  Therefore, the object of the present invention is not to require a large-scale and complicated configuration, and further, without reducing the degree of vacuum in the space between the electron beam column and the electron beam emitting hole and the electron beam irradiated object. An object of the present invention is to provide an electron beam irradiation method and an electron beam irradiation apparatus capable of irradiating a (disk) with an electron beam.

  A further object of the present invention is to provide an electron beam irradiation method and an electron beam irradiation apparatus capable of maintaining a jitter value within a predetermined preferable range when an electron beam is irradiated onto a substrate.

  A first embodiment of the present invention includes a head that includes a support portion that supports a disk to which an electron beam is irradiated and a facing surface that faces the disk with a minute gap, and the head is provided on the facing surface. In addition, an electron beam exit hole through which the electron beam is emitted toward the disk, an electron beam passage communicating with the electron beam exit hole, and one or more ring-shaped gas suctions that open around the electron beam passage on the opposing surface The electron beam passage and the ring-shaped gas suction groove are connected to the exhaust means, respectively, and the support portion changes the relative positional relationship between the electron beam emission hole and the disk so that the electron beam This is an electron beam irradiation apparatus that controls to irradiate the disk in order from the outside to the inside.

  With this configuration of the electron beam irradiation apparatus according to the present invention, the electron beam is irradiated in order from the outside to the inside of the disk, and as a result, a higher degree of vacuum is maintained near the position where the electron beam is irradiated to the disk. .

  According to a second embodiment of the present invention, in the electron beam irradiation apparatus according to the first embodiment of the present invention, the electron beam irradiation is performed to form a fine uneven pattern on the disk. The linear velocity at which the electron beam scans on the disk is an electron beam irradiation device that is substantially equal to the linear velocity at which the irradiation spot scans the recording medium when reproducing a recording medium manufactured by a disk on which a fine concavo-convex pattern is formed. is there.

  With this configuration of the electron beam irradiation apparatus according to the present invention, the electron beam irradiation performed in order from the outer side to the inner side of the disk is performed at the same linear velocity as that during reproduction. Even in such a case, the electron beam is applied to the disk. A higher degree of vacuum is maintained in the vicinity of the irradiated position.

  According to a third embodiment of the present invention, in the electron beam irradiation apparatus according to the first embodiment of the present invention, the support unit is controlled so that the electron beam is irradiated spirally from the outer side to the inner side of the disk. This is an electron beam irradiation apparatus.

  With this configuration of the electron beam irradiation apparatus according to the present invention, the electron beam is irradiated spirally from the outside to the inside of the disk, and as a result, a higher degree of vacuum is obtained in the vicinity of the position where the electron beam is applied to the disk. Maintained.

  A fourth embodiment of the present invention includes a head that includes a support portion that supports a disk irradiated with an electron beam, and a facing surface that faces the disk with a minute interval, and the head is provided on the facing surface. In addition, an electron beam exit hole through which the electron beam is emitted toward the disk, an electron beam passage communicating with the electron beam exit hole, and one or more ring-shaped gas suctions that open around the electron beam passage on the opposing surface In the electron beam irradiation method using the electron beam irradiation apparatus configured to have a groove, and the electron beam passage and the ring-shaped gas suction groove are respectively connected to the exhaust unit, the electron beam emitting hole and the disk Electron beam irradiation method having a position control step of controlling the electron beam to be irradiated in order from the outside to the inside of the disk by changing the relative positional relationship between A.

  With this configuration of the electron beam irradiation method according to the present invention, the electron beam is irradiated in order from the outside to the inside of the disk, and as a result, a higher degree of vacuum is maintained near the position where the electron beam is irradiated on the disk. .

  According to a fifth embodiment of the present invention, in the electron beam irradiation method according to the fourth embodiment of the present invention, the electron beam irradiation is performed to form a fine uneven pattern on the disk. In the position control step, the linear velocity at which the electron beam scans on the disk is substantially equal to the linear velocity at which the irradiation spot scans on the recording medium when reproducing the recording medium manufactured by the disk on which the fine uneven pattern is formed. This is an electron beam irradiation method controlled to be

  With this configuration of the electron beam irradiation method according to the present invention, the electron beam irradiation performed in order from the outside to the inside of the disk is performed at the same linear velocity as that during reproduction. Even in such a case, the electron beam is applied to the disk. A higher degree of vacuum is maintained in the vicinity of the irradiated position.

  According to a sixth embodiment of the present invention, in the electron beam irradiation method according to the fourth embodiment of the present invention, in the position control step, the electron beam is irradiated in a spiral shape from the outside to the inside of the disk. Electron beam irradiation method to be controlled.

  With this configuration of the electron beam irradiation method according to the present invention, the electron beam is irradiated spirally from the outside to the inside of the disk, and as a result, a higher degree of vacuum is obtained in the vicinity of the position where the electron beam is applied to the disk. Maintained.

  By the electron beam irradiation method and the electron beam irradiation apparatus according to the present invention, the degree of vacuum in the space between the electron beam column and the electron beam emitting hole and the electron beam irradiated object is reduced with a small-scale and simple configuration. Without irradiating the substrate with an electron beam. In addition, such a configuration further reduces damage to the electron gun.

  Further, the electron beam irradiation method and the electron beam irradiation apparatus according to the present invention can irradiate the substrate with the electron beam without increasing the jitter value.

  Initially, with reference to FIG. 1, the structure of the electron beam irradiation apparatus which concerns on one Embodiment of this invention is demonstrated. FIG. 1 is a schematic diagram showing the configuration of an electron beam irradiation apparatus according to an embodiment of the present invention.

  An electron beam irradiation apparatus 1 shown in FIG. 1 has an electron beam column 2, a support portion 4 that supports an electron beam irradiated body 3 irradiated with an electron beam 7, and a minute interval d with respect to the electron beam irradiated body 3. An electron beam irradiation head 6 having an electron beam emission hole 5 that faces the electron beam irradiation object 3 and irradiates the electron beam 7 is included.

  The electron beam column 2 includes an electron beam generating unit 10 and an electron beam converging unit 16, and a limiting plate 15 having an aperture 14 in the center is disposed between them. The electron beam generator 10 further includes an electron gun 11, a condenser electron lens 12 that converges the electron beam emitted from the electron gun 11, and an electron beam modulation means 13. On the other hand, the electron beam converging unit 16 includes a deflecting unit 17, a focus adjusting unit 18, and an objective electron lens 19.

  Here, the electron beam modulation means 13 is composed of, for example, opposing deflection electrode plates, deflects the electron beam by applying a required voltage therebetween, and transmits the aperture 14 of the limiting plate 15. Further, on / off modulation is performed by blocking the electron beam by the limiting plate 15. Further, the deflection means 17 performs deflection for causing the electron beam to reciprocate and move minutely in the electron beam irradiated body 3 (so-called wobbling). The deflecting means 17 is also composed of, for example, opposing deflecting electrode plates, and a wobbling signal is input between these electrodes.

  The focus adjusting unit 18 and the objective electron lens 19 are each composed of, for example, an electromagnetic coil. The focus adjusting unit 18 and the objective electron lens 19 allow the electron beam 7 to pass through the electron beam irradiation head 6 to be irradiated with the electron beam. Focusing is performed on the irradiation body 3. In this case, for example, a focusing servo signal is applied to the focus adjusting means 18. Further, as the electron beam column 2 described above, although the degree of vacuum is somewhat low on the emission side of the electron beam as in a column used in a scanning electron microscope for low vacuum, for example, the electron gun 11 side Therefore, it is possible to adopt a configuration in which the degree of vacuum is given a gradient with higher vacuum, and in this case, electron beam irradiation can be performed more stably.

  Next, the electron beam irradiation head 6 will be described in more detail with reference to FIGS. FIG. 2 is a schematic diagram showing a cross-sectional view of the electron beam irradiation head 6, and FIG. 3 is a front view of the electron beam irradiation head 6.

  The electron beam irradiation head 6 has a block 21 made of, for example, ceramic or metal, and an electron beam passage 20 communicating with the electron beam emission hole 5 is provided there. In addition, the block 21 is provided with one or more gas suction grooves that are open so as to face the electron beam irradiated body 3 and are arranged concentrically around the electron beam emission hole 5. In this example, a first ring-shaped gas suction groove 61 and a second ring-shaped gas suction groove 62 are formed.

  The block 21 includes a static pressure levitation means 22 (compressed gas passage 22a, ventilation pad 22b) of the electron beam irradiation head 6 on the outer periphery of the first ring-shaped gas suction groove 61 and the second ring-shaped gas suction groove 62. ), That is, a so-called hydrostatic bearing is provided. The block 21, that is, the electron beam irradiation head 6 is connected to the fixed portion 40 of the electron beam column 2 by expansion / contraction means 41 such as a bellows. It is held so as to be movable in the axial direction indicated by a.

  By making the electron beam irradiation head 6 movable, the distance between the electron beam irradiation head 6 and the electron beam irradiated object 3 is always changed by, for example, the operation of the static pressure levitation means 22 as described later. It becomes possible to maintain a constant interval without depending on the unevenness of the thickness of the irradiating body 3 or the like. In this case, the expansion / contraction coupling means 41 is secretly configured. Further, the electron beam 7 from the electron beam column 2 passes through the central cavity portion of the expansion / contraction coupling means 41 and passes through the electron beam passage 20 of the block 21.

Then, for example, an evacuation unit, that is, a vacuum pump, is connected to the electron beam passage 20, the first ring-shaped gas suction groove 61, and the second ring-shaped gas suction groove 62, respectively. In this case, a relatively high degree of vacuum can be obtained by the evacuation means 50 connected to the electron beam passage 20. For example, a vacuum capacity of 1 × 10 ⁻⁸ [Pa], such as a cryopump, a turbo molecular pump, or an ion sputtering pump. The electron beam passage 20 is evacuated to about 1 × 10 ⁻⁴ [Pa] using an exhaust means 50 having

Further, an exhaust unit capable of exhausting at a higher degree of vacuum is connected to the central portion of the block 21, that is, the gas suction groove closer to the electron beam emission hole 5. That is, the first ring-shaped gas suction groove 61 is provided with an evacuation means 51 having a degree of vacuum of about 1 × 10 ⁻¹ [Pa], for example, and the second ring-shaped gas suction groove 62 is provided with, for example, 5 × The exhaust means 52 that can obtain a degree of vacuum of about 10 ³ [Pa] is connected.

  Further, the static pressure levitation means 22 is configured in a ring shape at a portion facing the electron beam irradiated body 3. For example, the electron beam emitting hole 5 is centered on the outer periphery of the outer gas suction groove (in the example of FIG. 2, the second gas suction groove 62) that opens on the surface of the block 21 that faces the electron beam irradiated object 3. It is formed in a ring shape. The static pressure levitation means 22 has, for example, a configuration in which a ring-shaped compressed gas passage 22a and a ventilation pad 22b arranged so as to fill the opening are arranged.

A compressed gas supply source 53 is connected to the ring-shaped compressed gas passage 22a, and the compressed gas is supplied at, for example, 5 × 10 ⁵ [Pa]. As this gas, for example, nitrogen (N) or an inert gas, and light atoms such as helium (He), neon (Ne), and argon (Ar) are preferably used. As will be described later, this gas does not enter the electron beam passage 20, but even when an unexpected situation occurs and this gas enters the electron beam passage 20, the electron emission cathode material of the electron gun 11 is used. It is desirable to prevent deterioration. The pad 22b is preferably a porous pad having a high load capacity per hydrostatic bearing area and high rigidity.

  Here, with reference to FIG. 3, the dimension of each part of the electron beam irradiation head 6 is illustrated. For example, the diameter of the electron beam emitting hole 5 is about 10 μm to 200 μm, the distance D1 from the center of the electron beam emitting hole 5 to the first ring-shaped gas suction groove 61 is about 2.5 mm, and the first ring-shaped gas suction groove 61 has a width W1 of about 4 mm to 5 mm, a distance D2 between the first ring-shaped gas suction groove 61 and the second ring-shaped gas suction groove 62 is about 2 mm, and a width W2 of the second ring-shaped gas suction groove 62 is about 2 mm, the distance D3 between the second ring-shaped gas suction groove 62 and the static pressure levitation means 22 is about 2 mm, the width W3 of the static pressure levitation means 22 is about 5 mm to 10 mm, and the circumference of the block 21 from the static pressure levitation means 22 The distance (width) D4 to the surface can be selected to be about 2 mm.

  Although not shown in the drawings, for example, in the connection between the electron beam irradiation head 6 and the electron beam column 2, in the vicinity of the end on the electron beam column 2 side, or in the connection between the electron beam irradiation head 6 and the electron beam column 2. A gate valve for opening and closing the electron beam passage is provided in the vicinity of the end on the electron beam irradiation head 6 side.

  Referring to FIG. 2 again, the support 4 of the electron beam irradiated body 3 includes a turntable having a suction means 23 such as a vacuum chuck or an electrostatic chuck. The turntable is configured to be able to rotate about a rotation axis that passes through the center of the plate surface of the electron beam irradiated body 3 and is perpendicular to the plate surface by the spindle shaft 24.

  The support 4 of the electron beam irradiated body 3 includes a first support 25 for supporting the spindle shaft 24 and a second support 26 for supporting the first support 25 (see FIG. 1). The first support base 25 is configured to move on the second support base 26. With such a configuration, as indicated by an arrow b, the electron beam irradiated object 3 extends along the extending direction of the plate surface of the electron beam irradiated object 3 from the center of the plate surface to the outside of the plate surface. Moves almost linearly along the connecting line. Due to this rotation and movement, the relative positional relationship between the electron beam emitting hole 5 and the electron beam irradiated object 3 changes with time, and the electron beam 7 changes with respect to the irradiation surface of the electron beam irradiated object 3. It is possible to scan in a spiral shape or with a plurality of concentric circles.

  As the movement control unit (not shown) that performs the above-described movement, it is desirable to use an ultrasonic linear motor, a magnetic shield type voice coil motor, or the like that can be magnetically driven so as to avoid the influence on the electron beam. Further, this control is desirably performed by feedback control from a linear scale having a resolution of 10 nanometers or less.

  In addition, the spindle shaft 24 is preferably configured to be supported by a hydrostatic air bearing. In this way, the rotation (speed) accuracy can be improved by enabling smooth rotation, and the electron beam 7 The irradiation pattern accuracy can be improved. A rotation control unit (not shown) that controls such rotation includes a drive motor that rotates the spindle shaft, and this drive motor is also a brushless magnetically shielded drive unit so as not to affect the electron beam. It is desirable to use a motor.

  Next, with reference to FIG. 4, a procedure for producing a master for manufacturing a recording medium will be described. In this case, as shown in FIG. 4A, the electron beam irradiated body 3 is a disc in which a resist 32 is uniformly applied with a predetermined thickness on a substrate 31 having high flatness and excellent surface smoothness as a whole. It is a shape. For example, when producing a recording medium manufacturing master, the substrate 31 is made of a glass substrate, a quartz substrate, a silicon wafer, or the like, and the resist 32 is made of a positive type or negative type photoresist.

  The resist 32 is irradiated with an electron beam 7 in a pattern corresponding to a target fine uneven pattern, and then developed to remove a portion irradiated with the electron beam 7 or a non-irradiated portion. Thus, a fine pattern 71 is formed on the resist 32. In this way {HYPERLINK "file: /// C: \\ Documents% 20and% 20Settings \\ kato1 \\% 83f% 83X% 83N% 83g% 83b% 83v \\ 04906225 \\% 8E% 91% 97% BF \\ JP-A-2002-222749.files \\ 000006.gif ", FIG. 4} B, a master 72 having a fine unevenness pattern by the fine pattern 71 of the resist 32 is obtained.

  Next, {HYPERLINK "file: /// C: \\ Documents% 20and% 20Settings \\ kato1 \\% 83f% 83X% 83N% 83g% 83b% 83v \\ 04906225 \\% 8E% 91% 97% BF \\ JP-A-2002-222749.files \\ 000006.gif ", Figure 4} As shown in FIG. 4C, Ni plating or the like is applied to the master 72, and this is peeled off from the master 72 and {HYPERLINK" file: /// C: \\ Documents% 20and% 20Settings \\ kato1 \\% 83f% 83X% 83N% 83g% 83b% 83v \\ 04906225 \\% 8E% 91% 97% BF \\ JP-A- 2002-222749.files \\ 000006.gif ", FIG. 4} D, a stamper 74 having a fine concavo-convex pattern 73 is produced.

  Using the stamper 74 thus obtained, a recording medium having a fine concavo-convex pattern is manufactured by injection molding or 2P method.

  In the above-described example, the stamper is transferred and produced by the master, but a master stamper for transferring and replicating a plurality of stampers can be produced, and a mother stamper for transferring and producing the master stamper can be obtained. In some cases, the substrate 31 is a substrate constituting the recording medium itself, and a resist 32 patterned by the above-described method is formed thereon, and this is used as a mask on the substrate, for example, RIE (reactive ion). Etching) The recording medium can be directly formed by performing etching, and similarly, it can be applied to the case of directly forming a stamper, a master stamper and a mother stamper.

  Next, the case where the electron beam 7 is drawn on the electron beam irradiated body 3 by the electron beam irradiation apparatus 1 according to an embodiment of the present invention will be described.

  Here, the distance d between the electron beam irradiation head 6 and the surface of the electron beam irradiated body 3 (that is, the electron beam irradiation surface) of the electron beam irradiation apparatus 1 is a narrow distance of about 5 μm, for example.

  First, the electron beam irradiated body 3 is placed on the suction means 23 of the support portion 4. Then, the suction unit 23 sucks and holds the electron beam irradiated body 3. In this state, the electron beam irradiation head 6 is brought close to the electron beam irradiation surface of the electron beam irradiated body 3, that is, the application surface of the resist 32. At this time, the static pressure levitation means 22 is in an operating state and is in a state where gas is ejected from the ventilation pad 22b. However, in the first and second ring-shaped gas suction grooves 61 and 62, a gas suction operation is performed. The state is not performed.

  In this way, the jet gas from the static pressure levitation means 22 is blown onto the electron beam irradiation surface of the electron beam irradiated body 3, so that the electron beam irradiation head 6 collides with or comes into contact with the irradiation surface. The distance d between the electron beam irradiated body 3 and the electron beam irradiation surface is larger than a suitable distance that is finally retained, but is maintained in a coarsely adjusted state at an interval close thereto.

  In this state, by adjusting the suction operation of the first ring-shaped gas suction groove 61 and the second ring-shaped gas suction groove 62, that is, the vacuum evacuation, the positive gas pressure by the static pressure levitation means 22 and the first The interval d is set to a predetermined narrow interval, for example, 5 μm, by the differential of negative pressure by the ring-shaped gas suction groove 61 and the second ring-shaped gas suction groove 62.

  After the degree of vacuum of the first ring-shaped gas suction groove 61 and the second ring-shaped gas suction groove 62 has increased to a predetermined value, the gate valve provided in the electron beam column 2 or the like is opened, and the electron beam emission hole 5 is opened. Then, the electron beam 7 is irradiated onto the electron beam irradiated body 3. Then, by rotating and shifting the electron beam irradiated body 3, the electron beam 7 is irradiated on the electron beam irradiated body 3, that is, the resist 32 with a spiral or concentric locus.

  At this time, a modulation signal corresponding to the irradiation pattern of the target electron beam 7 is applied to the electron beam modulation means 13 to turn the electron beam 7 on and off, so that the target irradiation pattern is spiral or concentric. To form. When wobbling this locus, a desired electron beam wobbling can be performed by applying a required wobbling signal to the deflection means 17 described above.

  At this time, the electron beam passage 20 communicating with the electron beam emitting hole 5 for the electron beam irradiated body 3 is evacuated by the evacuation means 50 and is in a vacuum state, while gas is ejected from the static pressure levitation means 22. However, since the first ring-shaped gas suction groove 61 and the second ring-shaped gas suction groove 62 are provided between the two, that is, around the electron beam emission hole 5, the jetted gas is Suction by the first ring-shaped gas suction groove 61 and the second ring-shaped gas suction groove 62 is avoided from reaching the electron beam emission hole 5.

  This suction mechanism will be described in more detail. Most of the gas ejected from the static pressure levitation means 22 is first absorbed by the second ring-shaped gas suction groove 62, but those not absorbed here are also absorbed by the first ring-shaped gas suction groove 61. Absorbed. At this time, since the distance d between the electron beam irradiation head 6 and the electron beam irradiated body 3 is narrow, the second ring-shaped gas suction groove 62 and the first ring-shaped gas suction groove 61 The air conductance between the two becomes smaller. Further, as described above, the distance D1 between the first ring-shaped gas suction groove 61 and the electron beam emission hole 5 shown in FIG. By increasing the degree of vacuum, the ventilation conductance between the first ring-shaped gas suction groove 61 and the electron beam emission hole 5 becomes extremely small.

  Due to such a configuration, leakage of gas molecules into the electron beam emission hole 5 is almost avoided. In this way, the electron beam path 20 in the electron beam irradiation head 6 can be maintained at a high vacuum, and further, the flight path led out from the electron beam emission hole 5 toward the electron beam irradiated body 3 can also be maintained at a high vacuum. .

  Next, a more specific method for drawing the electron beam 7 on the electron beam irradiated body 3 by the electron beam irradiation apparatus 1 according to an embodiment of the present invention will be described. In the case of producing a master for producing a recording medium having a fine concavo-convex pattern, conventionally, the cutting is performed spirally from the inner side to the outer side of the disc. When cutting using this method, if the electron beam irradiated body 3 is rotated at a high speed, the degree of vacuum of the column may be reduced, and the electron gun 11 may be damaged. In addition, the jitter gradually deteriorates due to such high-speed rotation. For example, when a Blu-ray disc master is created, the jitter value may exceed the Blu-ray disc standard.

  Therefore, cutting is performed in a spiral shape from the outside to the inside (that is, a path opposite to the above-described path of the conventional cutting method) to form a fine uneven pattern. When cutting is performed using this method, the degree of vacuum that damages the electron gun 11 is not reached even with a linear velocity of 4.92 m / s, which is real-time cutting. In addition, the jitter value described above can be improved as compared with the conventional cutting method in which a spiral shape is formed from the inside to the outside.

  Cutting with the electron beam 7 passes through the center of the plate surface of the electron beam irradiated body 3 and rotates about the rotation axis perpendicular to the plate surface, and radially outward from the center of the electron beam irradiated body 3. This is done by movement along the direction extending to.

  In order to perform cutting spirally from the outside to the inside, the above-described rotation is controlled so as to be performed in a direction opposite to the case where the cutting is performed spirally from the inside to the outside of the electron beam irradiated body 3. . Such rotation is performed by the above-described rotation control unit, and the rotation control unit controls the rotation direction of the spindle shaft 24 so that the electron beam irradiated body 3 rotates in the reverse direction as described above.

  Further, it is desirable that the cutting, that is, the irradiation with the electron beam 7 is performed at substantially the same linear velocity (for example, the above-mentioned 4.92 m / s) over the electron beam irradiated object 3. Therefore, at the time of cutting, the rotation control unit controls to gradually change the rotation speed of the electron beam irradiated object 3 to a higher speed as the electron beam irradiated object 3 proceeds from the outside to the inside.

  On the other hand, in order to perform the cutting spirally from the outside to the inside, the above-described movement along the direction extending radially outward from the center of the electron beam irradiated body 3 is also performed by the cutting. 3 is controlled in the direction opposite to the spiral direction from the inside to the outside. Such a substantially radial movement is performed by the above-described movement control unit, which moves the spindle on the support unit 4 so that the electron beam irradiated body 3 moves in the reverse direction as described above. The positions of the shaft 24 and the suction means 23 are controlled.

  At the beginning of cutting, the movement control unit positions the electron beam irradiated body 3 so that the electron beam 7 is irradiated to the outside of the electron beam irradiated body 3, and the electron beam 7 is moved to the electron as the cutting progresses. The electron beam irradiated body 3 is positioned so as to be irradiated on the inner side of the beam irradiated body 3.

  Further, the electron beam modulation means 13 receives a modulation signal corresponding to the irradiation pattern of the target electron beam 7 and turns on / off the electron beam 7 on the basis of the modulation signal, thereby changing the target irradiation pattern to the electron beam coverage. In this example, the modulation signal provided to the electron beam modulation means 13 is also cut in a spiral shape from the inside to the outside of the electron beam irradiated body 3. Provided in the reverse order. Such modulation signal control is performed, for example, by a modulation signal providing unit (not shown) that receives recording data, generates an irradiation pattern, and provides the modulation signal corresponding to the irradiation pattern to the electron beam modulation means 13.

  The operations of the rotation control unit, the movement control unit, and the modulation signal providing unit described above are normally controlled by one or each corresponding microcomputer.

  Next, referring to the graph of FIG. 5, the cutting is performed in a spiral shape from the inside to the outside of the electron beam irradiated body 3 and the cutting of the electron beam irradiated body 3 as in the present invention. A description will be given of the results of measuring how the degree of vacuum changes when spiraling from the outside to the inside. The degree of vacuum shown here is the degree of vacuum measured by the electron beam column 2.

  The vertical axis of the graph in FIG. 5 represents the value obtained by dividing the vacuum degree of the electron beam column 2 by the vacuum degree of the electron beam column that causes some damage to the electron gun 11, and the horizontal axis represents a disk-shaped recording medium (electron It represents the distance from the center of the beam irradiated body 3). Therefore, on the horizontal axis of the graph, the greater the distance, the more outside the disc.

  A straight line 101 indicates a state in which some damage is given to the electron gun 11, and if the degree of vacuum exceeds this, there is a high possibility that some damage will be given to the electron gun 11.

  A curve 102 represents a change in the degree of vacuum when the cutting is performed in a spiral shape from the inner side to the outer side of the disk (electron beam irradiated body 3). As indicated by the arrow e, the curve 102 starts from the inside of the disk and proceeds to the outside of the disk as cutting is performed. In this case, the degree of vacuum has reached the level of the straight line 101 in a state where cutting has progressed to about 40 mm from the center of the disk, and it can be seen that damage to the electron gun 11 cannot be avoided by this method.

  On the other hand, the curve 103 shows the change in the degree of vacuum when the cutting is performed spirally from the outside to the inside of the disk (electron beam irradiated object 3), that is, when the electron beam irradiation method of the present invention is used. Represents. As shown by the arrow f, the curve 103 starts from the outside of the disk and proceeds to the inside of the disk as cutting is performed. In this case, the degree of vacuum is highest between 60 mm and 55 mm from the center of the disk, but it is still a level that does not reach the level of the straight line 101. Thereafter, as the cutting progresses, the electron beam 7 is irradiated at a position on the inner side of the disk, and the degree of vacuum gradually decreases. Thus, in the electron beam irradiation method of the present invention, it can be seen that the degree of vacuum changes at a low level that does not damage the electron gun 11 in the entire cutting range.

  Up to this point, the electron beam irradiation method of the present invention has been described by taking an example in which the electron beam irradiation proceeds in a spiral shape from the outside to the inside of the disk. It should be noted that the electron beam 7 can be irradiated concentrically by appropriately controlling the movement of the disk by the control unit, and such an irradiation method is also included in the electron beam irradiation method of the present invention.

It is a basic diagram showing the structure of the electron beam irradiation apparatus 1 which concerns on one Embodiment of this invention. It is an approximate line figure showing the composition of the section of electron beam irradiation head 6 of electron beam irradiation apparatus 1 concerning one embodiment of the present invention in detail. It is a front view of the electron beam irradiation head 6 of the electron beam irradiation apparatus 1 which concerns on one Embodiment of this invention. It is a basic diagram which shows the process in which the disk original disc is produced in the electron beam irradiation apparatus 1 which concerns on one Embodiment of this invention. In making the master disc, the difference in the degree of vacuum when the electron beam is irradiated spirally from the inside to the outside of the disc and when the electron beam is irradiated spirally from the outside to the inside of the disc It is a graph to show.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electron beam irradiation apparatus, 2 ... Electron beam column, 3 ... Electron beam irradiated body, 4 ... Support part, 5 ... Electron beam emission hole, 6 ... Electron beam irradiation Head, 7 ... Electron beam, 10 ... Electron beam generator, 11 ... Electron gun, 12 ... Condenser electron lens, 13 ... Electron beam modulation means, 14 ... Aperture, 15 ..Limiting plate, 16 ... electron beam converging unit, 17 ... deflecting means, 18 ... focus adjusting means, 19 ... objective electron lens

Claims (10)

A support for supporting a disk to be irradiated with an electron beam;
A head having a facing surface facing the disk at a minute interval;
The head is
An electron beam emission hole provided on the facing surface, from which the electron beam is emitted toward the disk;
An electron beam passage communicating with the electron beam emission hole;
One or more ring-shaped gas suction grooves that open at the facing surface are provided around the electron beam path,
The electron beam passage and the ring-shaped gas suction groove are respectively connected to exhaust means,
The support unit controls the electron beam to be irradiated in order from the outside to the inside of the disk by changing a relative positional relationship between the electron beam emission hole and the disk. An electron beam irradiation device. The electron beam irradiation apparatus according to claim 1,
The electron beam irradiation is performed to form a fine uneven pattern on the disk,
In this case, a linear velocity at which the electron beam scans the disk is a line at which an irradiation spot scans the recording medium when reproducing the recording medium manufactured by the disk on which the fine uneven pattern is formed. An electron beam irradiation apparatus characterized by being substantially equal to the speed. The electron beam irradiation apparatus according to claim 1,
The electron beam irradiation apparatus according to claim 1, wherein the support unit controls the electron beam to be irradiated in a spiral shape from the outside to the inside of the disk. The electron beam irradiation apparatus according to claim 1,
The electron beam irradiation apparatus according to claim 1, wherein the support unit controls the electron beam to be irradiated along a plurality of concentric trajectories from the outside to the inside of the disk. The electron beam irradiation apparatus according to claim 1,
The support part is
Rotating means for rotating the disk around the center of the plate surface of the disk as a rotation axis;
A moving means for moving the disc substantially linearly along the direction of extension of the plate surface of the disc and along a line connecting the outside of the plate surface from the center of the plate surface;
By controlling the rotating means and the moving means, the relative positional relationship between the electron beam emitting hole and the disk is changed so that the electron beam is irradiated in order from the outside to the inside of the disk. An electron beam irradiation apparatus characterized in that A support for supporting a disk to be irradiated with an electron beam;
A head having a facing surface facing the disk at a minute interval;
The head is
An electron beam emission hole provided on the facing surface, from which the electron beam is emitted toward the disk;
An electron beam passage communicating with the electron beam emission hole;
One or more ring-shaped gas suction grooves that open at the facing surface are provided around the electron beam path,
In the electron beam irradiation method using the electron beam irradiation apparatus, the electron beam passage and the ring-shaped gas suction groove are configured to be connected to an exhaust unit, respectively.
A position control step for controlling the electron beam to be irradiated in order from the outside to the inside of the disk by changing a relative positional relationship between the electron beam emitting hole and the disk at the support portion; An electron beam irradiation method comprising: The electron beam irradiation method according to claim 6.
The electron beam irradiation is performed to form a fine uneven pattern on the disk,
In this case, in the position control step, the linear velocity at which the electron beam scans the disk is such that an irradiation spot is recorded when the recording medium manufactured by the disk on which the fine concavo-convex pattern is formed is reproduced. An electron beam irradiation method characterized by controlling so as to be substantially equal to a linear velocity of scanning on a medium. The electron beam irradiation method according to claim 6.
In the position control step, the electron beam irradiation method is controlled such that the electron beam is irradiated in a spiral shape from the outside to the inside of the disk. The electron beam irradiation method according to claim 6.
The position control step performs control so that the electron beam is irradiated with a plurality of concentric trajectories from the outside to the inside of the disk. The electron beam irradiation method according to claim 6.
The position control step includes
A rotation control step of rotating the disk about the center of the plate surface of the disk by a rotation means;
A moving control step of moving the disk substantially linearly along the direction of extension of the plate surface of the disk and along a line connecting the outside of the plate surface from the center of the plate surface by moving means;
The rotation control step and the movement control step change the relative positional relationship between the electron beam emission hole and the disk so that the electron beam is irradiated in order from the outside to the inside of the disk. An electron beam irradiation method comprising controlling the rotating means and the moving means.

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