JP4251525B2 - Disc master production equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a manufacturing apparatus for manufacturing a master disc by irradiating a substrate with an electron beam.
[0002]
[Prior art]
In recent years, various recording media capable of recording large-capacity image / audio data and digital data have been developed. For example, there are optical discs such as DVDs (Digital Versatile Discs), and research and development are progressing to increase the storage capacity of an optical disc having a diameter of 12 cm to 30 GB (Giga-Byte).
[0003]
However, in conventional cutting of an optical disc master using visible or ultraviolet laser light, the recording resolution is limited by the spot diameter of the recording laser light. Therefore, in order to increase the density of the optical disk described above, the optical disk master is produced by a disk master manufacturing apparatus using an electron beam that has a spot diameter smaller than that of visible or ultraviolet laser light and can improve the recording resolution. Manufacturing, so-called cutting, has been studied.
[0004]
Such an optical disc master is manufactured by applying an electron beam resist to a substrate and then irradiating an electron beam in a vacuum atmosphere. A fine pattern latent image is formed on the electron beam resist by electron beam irradiation (electron beam exposure). Such a substrate is subjected to development processing, patterning and resist removal processing to form a fine uneven pattern on the substrate.
[0005]
Also in the manufacture of a disk substrate such as a magnetic recording hard disk, a process of forming a fine pattern using an electron beam is performed.
[0006]
[Problems to be solved by the invention]
In order to manufacture a high density disk in a disk master manufacturing apparatus using an electron beam, it is necessary to rotate the disk substrate with high accuracy. In order to obtain a high recording resolution, the electron beam must be converged finely. In this case, the electron beam speed is increased. On the other hand, since a high-speed electron beam passes through without being absorbed by the electron beam resist layer, there is a problem that the exposure amount is reduced and the resolution is lowered.
[0007]
The present invention has been made in view of the above-described points, and an object of the present invention is to provide a highly accurate disk master manufacturing apparatus that enables manufacturing of a high-density disk.
[0008]
[Means for Solving the Problems]
A disk master manufacturing apparatus according to the present invention is a manufacturing apparatus for manufacturing a disk master by irradiating a substrate with an electron beam, and has an electron beam emitting portion for emitting an electron beam, a through hole, and a substrate on its support surface. An insulating turntable that supports the spindle, a spindle housing, a spindle shaft rotatably supported on the spindle housing via a gas bearing, and one end fixed to the turntable, a motor that rotationally drives the spindle shaft, and an electronic An electron beam decelerating unit that applies a deceleration voltage of a magnitude that decelerates the electron beam of the beam to the substrate, and the electron beam decelerating unit is urged from the support surface through the through hole of the turntable. And a relay portion that relays the deceleration voltage to the conductive member via the rotary connector.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings used for the following description, the same reference numerals are given to the same components.
FIG. 1 is a block diagram showing a configuration of a master disk manufacturing apparatus 10 using an electron beam according to an embodiment of the present invention.
[0010]
First, an outline of the manufacturing process will be described below using an optical disc master as an example. The electron beam is used in a vacuum atmosphere because it has a characteristic of being significantly attenuated in the air atmosphere. Therefore, a turntable or the like on which a substrate for producing an electron gun or an optical disc master is placed in a vacuum atmosphere.
For manufacturing an optical disc master, for example, a silicon (Si) substrate is used. The silicon substrate is coated with an electron beam resist on its main surface. The substrate coated with the electron beam resist is rotated and irradiated with an electron beam modulated by an information data signal in the disk master production apparatus, and a latent image of a fine concavo-convex pattern such as pits and grooves is spirally formed. Formed.
[0011]
After the electron beam exposure is completed, the substrate is taken out from the disc master manufacturing apparatus and subjected to development processing. Next, patterning and resist removal processes are performed to form a fine uneven pattern on the substrate. A conductive film is formed on the main surface of the patterned substrate, and an electroforming process is performed to manufacture an optical disc master (stamper).
[0012]
As shown in FIG. 1, a disk master manufacturing apparatus 10 includes an electron including a vacuum chamber 11, a driving device that drives a disk substrate disposed in the vacuum chamber 11, and an electron beam optical system attached to the vacuum chamber 11. A beam emission head unit 40 is provided.
An optical disc substrate (hereinafter simply referred to as a disc substrate) 15 for an optical disc master is placed on a turntable 16. The turntable 16 is rotationally driven with respect to the vertical axis of the main surface of the disk substrate by an air spindle motor 17 which is a rotational drive device that rotationally drives the disk substrate 15. The air spindle motor 17 is accommodated in a feed stage (hereinafter simply referred to as a stage) 18. The stage 18 is coupled to a feed motor 19 which is a translation drive device, and can translate the air spindle motor 17 and the turntable 16 in a predetermined direction in a plane parallel to the main surface of the disk substrate 15. Yes. The turntable 16 is made of a dielectric material such as ceramic, and the disk substrate 15 is held on the turntable 16 by an electrostatic chucking mechanism described later.
[0013]
Further, the vacuum chamber 11 is provided with a light source 22, a light detector 23, and a height detector 24 for detecting the height of the main surface of the disk substrate 15. The photodetector 23 includes, for example, a position sensor, a CCD (Charge Coupled Device), etc., receives a light beam emitted from the light source 22 and reflected by the surface of the disk substrate 15, and receives the received light signal as a height detector 24. To supply. The height detection unit 24 detects the height of the main surface of the disk substrate 15 based on the light reception signal.
[0014]
The vacuum chamber 11 is installed via an anti-vibration table (not shown) such as an air damper, and transmission of vibration from the outside is suppressed. Further, a vacuum pump 28 is connected to the vacuum chamber 11, and the interior of the chamber is set to a vacuum atmosphere at a predetermined pressure by exhausting the inside of the chamber.
Further, a drive control unit 30 for controlling the air spindle motor 17 and the feed motor 19 is provided. The drive control unit 30 operates under the control of the CPU 25 that controls the entire disc master manufacturing apparatus 10.
[0015]
The electron beam emitting head unit 40 for emitting an electron beam includes an electron gun 41, a converging lens 42, a blanking electrode 43, an aperture 44, a beam deflection electrode 45, a focus adjustment lens 46, and an objective lens 47 in this order. The electron beam emission head unit 40 is disposed. The electron beam ejection head unit 40 is attached to the ceiling surface of the vacuum chamber 11 with an electron beam ejection port 49 provided at the tip of the electron gun barrel 48 directed to the space in the vacuum chamber 11. Further, the electron beam exit 49 is disposed to face a position close to the main surface of the disk substrate 15 on the turntable 16.
[0016]
The electron gun 41 emits an electron beam accelerated to, for example, several tens of KeV by a cathode (not shown) to which a high voltage supplied from the electron gun power source 51 is applied. The converging lens 42 converges the emitted electron beam and guides it to the aperture 44. The blanking drive unit 54 operates based on a signal from the recording control unit 52 and controls the blanking electrode 43 to perform on / off control of the electron beam. That is, a voltage is applied between the blanking electrodes 43 to greatly deflect the passing electron beam. As a result, the electron beam is not converged in the aperture hole of the aperture 44, and the electron beam is prevented from passing through the aperture 44, and can be turned off.
[0017]
In response to a control signal from the CPU 25, the beam deflection driving unit 55 applies a voltage to the beam deflection electrode 45 to deflect the passing electron beam. Thus, the position of the electron beam spot with respect to the disk substrate 15 is controlled. The focus lens driving unit 56 adjusts the focus of the electron beam spot irradiated on the main surface of the disk substrate 15 based on the detection signal from the height detection unit 24.
[0018]
As described above, when the cutting (electron beam exposure) of the disk substrate 15 is performed, if the electron beam is incident on the resist layer formed on the disk substrate 15 at a high speed, the electron beam passes through the resist layer, and the exposure amount. Decreases and the resolution decreases. Therefore, in the present invention, a deceleration voltage (−V _R ) (hereinafter referred to as a retarding voltage), which is a negative voltage with a magnitude for decelerating the electron beam of the electron beam, is applied to the disk substrate 15 (hereinafter described as a retarding voltage). In the above, it is called a retarding method). A voltage source 60 is provided for applying the retarding voltage and chucking voltage. Specifically, for example, when the acceleration voltage of the electron beam is 50 kV, the retarding voltage is −40 kV. The magnitude of the retarding voltage may be appropriately determined according to the acceleration voltage of the electron beam, the sensitivity characteristics of the resist layer, the resolution required for the disk master, and the like.
[0019]
Next, the retarding voltage application mechanism to the disk substrate 15 and the electrostatic chucking mechanism of the disk substrate 15 will be described in detail with reference to FIGS.
FIG. 2 is a cross-sectional view schematically showing an internal configuration of the spindle housing 17A including the air spindle motor 17 and the high voltage supply unit 37 of the disc master production apparatus 10 shown in FIG.
[0020]
A spindle shaft 12 and an electromagnetic motor 13 that rotationally drives the spindle shaft are accommodated in the spindle housing 17A of the air spindle motor 17. The spindle shaft 12 is rotatably supported by a spindle housing 17A via a gas bearing 14, and one end is fixed to the turntable 16. In this example, in the vicinity of the end of the spindle shaft 12, a pressure seal (magnetic fluid seal) 35 surrounds the spindle shaft 12 so as to be interposed in a radial gap between the opening of the spindle housing 17A and the spindle shaft 12. Is provided. The magnetic fluid seal 35 maintains the airtightness inside the spindle housing 17A. The spindle housing 17A and the spindle shaft 12 are grounded to the apparatus main body, that is, the vacuum chamber 11 by a magnetic fluid seal 35.
[0021]
A motor (main body) 13A that rotates the spindle shaft 12 is attached to the spindle shaft 12 in the spindle housing 17A. The spindle shaft 12 can be rotated using an electromagnetic force generated by passing a current through a coil 13B provided in the housing 17B. Thereby, the turntable 16 fixed to the end of the spindle shaft 12 outside the spindle housing 17A can be rotated.
[0022]
A coaxial cable 31 for supplying a high voltage to the disk substrate 15 and / or the turntable 16 is provided in the spindle housing 17A. More specifically, the coaxial cable 31 has an inner conductor (core wire) 31 </ b> A and an outer conductor 31 </ b> B, and is provided in a through hole formed in the center of the spindle shaft 12. A supply voltage from the voltage source 60 is supplied to the coaxial cable 31 via a power cable connector 38 and a high voltage supply unit 37 which are coaxial connectors.
[0023]
The gas bearing 14 is supplied with bearing air from the outside via a valve (not shown) and circulates in the gas bearing 14. This circulating air is exhausted out of the vacuum chamber 11 from the spindle housing 17A through a pipe (not shown).
FIG. 3 is a cross-sectional view schematically showing details of the high voltage supply unit 37 and the insulating flange 36 shown in FIG. Since a high voltage of several tens of kV is supplied to the coaxial cable 31, the coaxial cable 31 is insulated from the spindle shaft 12, which is a ground potential, by a pipe 62 made of an insulating material (for example, acrylic). The coaxial cable 31 rotates with the spindle shaft 12. A high voltage is supplied to the coaxial cable 31 via the rotary connector 61. More specifically, the inner conductor 61A and the outer conductor 61B of the rotating part of the rotary connector 61 are connected to the inner conductor 31A and the outer conductor 31B of the coaxial cable 31, respectively. Further, the inner conductor 61C and the outer conductor 61D of the non-rotating portion (fixed portion) of the rotary connector 61 are connected to the inner conductor 38A and the outer conductor 38B of the power cable connector 38, respectively. The support portion 37B for supporting the rotary connector 61 and the power cable connector 38 are insulated by an insulating member 37A. An insulating flange 36 is provided at the end of the coaxial cable 31 in the spindle housing 17A. As shown in FIG. 3, the insulating flange 36 and the insulating member 37 </ b> A are formed in a shape that can take a creepage distance.
[0024]
Therefore, the rotary connector 61 is electrically insulated from the spindle housing 17 </ b> A and the spindle shaft 12, and thus is electrically insulated from the vacuum chamber 11. That is, it is not necessary to use a connector that can withstand a high voltage of several tens of kV, and a small and low torque loss rotary connector can be used.
[0025]
A rolling bearing is used for the rotary connector 61, and mercury is used for the connecting portion between the rotating portion and the fixed portion. It is also possible to use a slip ring that connects the rotating part and the fixed part with a brush. In addition, as the insulating material of the insulating flange 36 and the insulating member 37A, epoxy resin or ceramic can be used.
[0026]
Accordingly, a retarding voltage (−V _R , for example, −40 kV) is supplied from the voltage source 60 to the inner conductor 31 A of the coaxial cable 31 via the power cable connector 38 and the rotary connector 61. Further, a voltage (−V _R −V _C ) obtained by adding a chucking voltage (−V _C , for example, −500 V) to the outer conductor 31 </ b> B of the coaxial cable 31 is supplied.
[0027]
As described above, the rotary connector 61 is used to supply a high voltage. However, the connection of the rotary connector 61 does not cause a decrease in rotational accuracy of the air spindle motor 17. 4 (a) and 4 (b) are cross-sectional views in directions orthogonal to each other, showing details of the support structure and electrical connection of the rotary connector. FIG. 5 is a plan view when viewed from the rotating parts 61A and 61B side. A floating ring 61F is attached to a rotary connector main body 61E which is a non-rotating portion of the rotary connector 61. The floating ring 61F has a through hole 61H through which the guide pin 61G is passed. The floating ring 61F is guided by guide pins 61G fixed to the rotary connector support portion 37B. The diameter of the through hole 61H is larger than the diameter of the guide pin 61G. That is, a gap is provided between the through hole 61H and the guide pin 61G. Further, the length of the guide pin 61G is longer than the thickness of the floating ring 61F. That is, the floating ring 61F can move freely within the range of the length of the guide pin 61G. The size of these gaps is, for example, 0.2 to 0.3 mm, and may be appropriately determined according to the type and performance of the air spindle motor and rotary connector used, the accuracy required for the apparatus, and the like. Accordingly, the rotary connector 61 can freely move along the central axis (rotation axis) of the spindle shaft 12 and in a plane perpendicular to the central axis within the range of these gaps. In other words, the rotary connector 61 is supported floating. It is not always necessary to use the floating ring 61F. For example, a protrusion may be provided on the rotary connector main body 61E instead of the floating ring 61F so that the rotary connector main body 61E does not rotate more than a certain angle.
[0028]
On the other hand, as shown in FIGS. 4A and 4B, the inner conductor 38A of the power cable connector 38 is electrically connected to the inner conductor 61C of the rotary connector 61 by the first connecting member 39A. The external conductor 38B of the power cable connector 38 is electrically connected to the external conductor 61D of the rotary connector 61 by the second connecting member 39B. The first and second connecting members 39A and 39B do not become an obstacle to the movement of the rotary connector 61, but are formed of a metal piece or the like having a small elastic constant that moderately suppresses vibration of the rotary connector 61. . Furthermore, the connecting members 39A and 39B have an elastic constant and contact resistance that do not cause a decrease in performance as a contact. For example, the first and second connection members 39A and 39B are made of gold-plated spring phosphor bronze.
[0029]
FIG. 6 is a cross-sectional view schematically showing details of the central portion of the turntable 16 of the disc master production apparatus 10 shown in FIG.
As described above, during the electron beam exposure, the retarding voltage (−V _R ) is applied to the disk substrate 15 supported on the turntable 16, and the electron beam of the electron beam incident on the disk substrate 15 is decelerated. It is configured to be able to. More specifically, the retarding voltage (−V _R ) supplied from the inner conductor 31A of the coaxial cable 31 is applied to the disk substrate 15 via the conductive member 26A formed of a conductor. The conductive member 26A is urged so that it can protrude and retract from a support surface through a through-hole provided in the turntable 16 through 26C. For example, the conductive member 26 </ b> A is biased by an elastic member 26 </ b> B such as a spring, and the retarding voltage is applied to the disk substrate 15 by pressing the conductive member 26 </ b> A to the disk substrate 15 placed on the turntable 16. Is done. The leading end of the conductive member 26A is formed in a smooth convex shape, and is configured to always contact the disk substrate 15 and apply a retarding voltage.
[0030]
The disk substrate 15 is attracted and held on the turntable 16 by an electrostatic chucking mechanism. More specifically, the voltage (−V _R −V _C ) supplied from the outer conductor 31B of the coaxial cable 31 is applied to the chucking electrode 21 via the chucking voltage conductive portions 27A and 27B. That is, when a predetermined chucking voltage (-V _C ) negative with respect to the potential of the disk substrate 15 is applied to the chucking electrode 21, electrostatic polarization occurs in the turntable 16 made of ceramic or the like, thereby attracting it It is something that demonstrates its power.
[0031]
As described above in detail, according to the present invention, the rotary connector 61 is used for high voltage connection between the rotating part and the fixed part, and the rotary connector 61 is not grounded. Therefore, it is not necessary to use a high withstand voltage, and a small and low torque loss rotary connector can be used. As a result, a high voltage can be supplied without impairing the rotational accuracy of the air spindle motor 17. In addition, by floatingly supporting the rotary connector 61, a high voltage can be supplied without adversely affecting the rotational accuracy of the air spindle motor 17.
[0032]
By adopting such a configuration, a retarding voltage is applied to decelerate the electron beam, thereby preventing a reduction in the exposure amount and resolution of the electron beam to the resist layer, and electron beam exposure without impairing the rotation accuracy of the substrate. It can be performed. Therefore, a high-density disk can be executed in a short time and with high accuracy.
[0033]
Further, by using an electrostatic chucking mechanism for chucking and holding the disk substrate 15, the disk substrate 15 can be reliably held on the turntable 16 even during rotation, and high-density exposure can be performed with high accuracy. It can be performed stably. Further, even a warped disk substrate can be held flat on the turntable 16 over the entire surface of the turntable 16 by electrostatic adsorption, so that high-density exposure can be performed with high accuracy and the focus of the electron beam is stable. Can also be improved.
[0034]
In addition, although the manufacturing apparatus of the optical disk master was described as an example, the present invention is not limited to this, and can be applied to an apparatus for manufacturing a magnetic disk or the like using an electron beam. The present invention can also be applied to a disk manufacturing apparatus that forms a fine shape by direct electron beam drawing without using a resist.
[0035]
【The invention's effect】
As is apparent from the above, according to the present invention, it is possible to realize a highly accurate disk master manufacturing apparatus that enables manufacturing of a high-density disk.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a master disk manufacturing apparatus using an electron beam according to an embodiment of the present invention.
2 is a cross-sectional view schematically showing a configuration inside a spindle housing including an air spindle motor and a high voltage supply unit of the disk master production apparatus shown in FIG. 1;
FIG. 3 is a cross-sectional view schematically showing details of a high voltage supply section and an insulating flange portion shown in FIG. 2;
FIG. 4 is a cross-sectional view in the direction perpendicular to each other, showing details of the support structure and electrical connection of the rotary connector.
FIG. 5 is a plan view of the rotary connector as viewed from the rotating part side.
FIG. 6 is a cross-sectional view schematically showing details of a central portion of the turntable.
[Explanation of main part codes]
DESCRIPTION OF SYMBOLS 10 Disc master production apparatus 11 Vacuum chamber 12 Spindle shaft 14 Gas bearing 15 Disc substrate 16 Turntable 17 Air spindle motor 17A Spindle housing 18 Stage 19 Feed motor 21 Chucking electrode 25 CPU
26A, 27A Conductive member 26B Elastic member 30 Drive control unit 31 Coaxial cable 35 Magnetic fluid seal 36 Insulating flange 37 High voltage supply unit 40 Electron beam injection head unit 60 Voltage source 61 Rotary connector 61F Floating ring 61G Guide pin 61H Through hole

Claims (6)

A manufacturing apparatus for manufacturing a disk master by irradiating a substrate with an electron beam,
An electron beam emitting section for emitting the electron beam;
An insulating turntable that has a through hole and supports the substrate on its support surface;
A spindle housing;
A spindle shaft rotatably supported by the spindle housing via a gas bearing and having one end fixed to the turntable;
A motor for rotationally driving the spindle shaft;
An electron beam decelerating unit that applies to the substrate a deceleration voltage having a magnitude that decelerates the electron beam of the electron beam,
The electron beam decelerating unit includes a conductive member that is urged from the support surface through the through hole of the turntable, and a relay unit that relays the deceleration voltage to the conductive member via a rotary connector. The manufacturing apparatus characterized by the above-mentioned. The manufacturing apparatus according to claim 1, further comprising a translation drive unit that translates the turntable relative to the electron beam emitting unit. The manufacturing apparatus according to claim 1, wherein the relay portion includes an insulating pipe inserted through the spindle shaft as a hollow and a high voltage cable inserted through the insulating pipe. The manufacturing apparatus according to claim 1, wherein the conductive member is biased by an elastic member. The manufacturing apparatus according to claim 1, wherein the rotary connector is insulated from a ground potential. The spindle shaft is grounded through a conductive magnetic fluid seal interposed between the spindle housing and the spindle shaft, and the rotary connector is insulated from the spindle shaft and the spindle housing. The manufacturing apparatus according to 1.

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