JP2003036573A - Apparatus for manufacturing master disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for manufacturing a master disk, which can manufacture a high-accuracy master disk. SOLUTION: The apparatus includes an electron beam emitting part which emits an electron beam, a deflection driving part which controls the deflection of the electron beam, a rotary driving part which rotatively drives a substrate, a movement driving part which relatively moves the electron beam emitting part and the substrate in a prescribed direction in a plane parallel to the major surface of the substrate, a distance measuring device which measures a displacement amount in the prescribed direction of the substrate in rotary driving, a non-synchronized component generator which calculates a weighted average value of a currently measured displacement amount by the distance measuring device and the accumulated displacement amount, in which calculation the weighted average value is calculated using the weighted average value for the substrate before one rotation as the accumulated displacement amount, and which generates, as the non-synchronized component, the value obtained by subtracting the weighted average value from the currently measured displacement amount, and a control part which adjusts the irradiation position of the electron beam by controlling the deflection driving part on the basis of the magnitude of the non-synchronized component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing apparatus for manufacturing a disk master by irradiating a substrate with an electron beam.

[0002]

2. Description of the Related Art In recent years, various optical discs such as DVD (Digital Video Disc or Digital Versatile Disc) capable of recording large-capacity image / audio data and digital data have been developed. For example, research and development has been conducted to increase the storage capacity of an optical disk having a diameter of 12 cm to 30 GB (Giga-Byte).

However, in the conventional cutting of a disc master using a laser beam in the visible or ultraviolet range, the recording resolution is limited by the spot diameter of the recording laser beam. Therefore, in order to increase the density of the above-mentioned disc, the disc master manufacturing apparatus using an electron beam, which has a smaller spot diameter than the laser light in the visible region and the ultraviolet region and can improve the recording resolution, is used. Cutting (electron beam exposure) is being considered.

[0004]

The high-density disk has a very fine track pitch of 1 μm or less.
Further, as the density becomes higher, it becomes necessary to reduce the track pitch. Therefore, not only high precision control of the electron beam but also high precision is required for the drive device for rotating / moving the substrate for disk master production. In particular, it is necessary to perform high-precision control for rotational shake and the like that occurs in such an apparatus, but it is still necessary to realize a practical disc master manufacturing apparatus that enables the production of a high-precision disc master. I haven't arrived.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a high-precision disk master manufacturing apparatus capable of manufacturing a high-density disk.

[0006]

A disk master manufacturing apparatus according to the present invention is an apparatus for manufacturing a disk master by irradiating a substrate with an electron beam, and includes an electron beam emitting section for emitting an electron beam and an electron beam emitting section. A deflection drive unit that performs deflection control, a rotation drive unit that rotationally drives the substrate, an electron beam emission unit, and a movement drive unit that relatively moves the substrate in a predetermined direction within a plane parallel to the main surface of the substrate, and rotation. A distance measuring device that measures the displacement amount of the board in the predetermined direction during driving is calculated, and a weighted average value of the displacement amount measured this time by the distance measuring device and the accumulated displacement amount is calculated. At the time of this calculation, one rotation of the substrate is performed. A weighted average value is calculated by using the previous weighted average value as the accumulated displacement amount, and an asynchronous component generator that generates a value obtained by subtracting the weighted average value from the measured displacement amount of this time as an asynchronous component and an asynchronous component Big It is characterized by having a control unit which forms an irradiation position adjustment of the electron beam by controlling the deflection drive unit based at the.

[0007]

Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings used in the following description, substantially equivalent components are designated by the same reference numerals. FIG. 1 is a block diagram showing an example of an optical disk master manufacturing apparatus using an electron beam according to an embodiment of the present invention. First, an outline of the manufacturing process of such an optical disc master will be described below.

The electron beam is used in a vacuum atmosphere because it has a characteristic of being significantly attenuated in the air atmosphere. Therefore, the driving device, the transfer device, and the like for the electron gun and the optical disk master (substrate) are used in a vacuum atmosphere. A silicon (Si) substrate, for example, is used for manufacturing the optical disc master. An electron beam resist is applied to the main surface of the silicon substrate. The substrate coated with the electron beam resist is rotatably driven in the optical disc master manufacturing apparatus and is irradiated with the electron beam modulated by the information data signal, so that the latent image of the fine concavo-convex pattern such as pits and grooves is spirally formed. Is formed.

After the electron beam exposure is completed, the substrate is taken out from the optical disk master manufacturing apparatus and subjected to a developing process. Next, patterning and resist removal processes are performed to form a minute uneven pattern on the substrate. A conductive film is formed on the surface of the patterned substrate, and electrocasting is performed to manufacture an optical disk master (stamper).

As shown in FIG. 1, an optical disk master manufacturing apparatus 10 includes a vacuum chamber 11, a drive device for driving a substrate arranged in the vacuum chamber 11, and an electron beam emitting head unit attached to the vacuum chamber 11. 40 is provided. An optical disk substrate (hereinafter, simply referred to as a disk substrate) 15 for an optical disk master is placed on a turntable 16. The turntable 16 is rotationally driven about a vertical axis of the main surface of the disk substrate by a spindle motor 17 which is a rotary driving device that rotationally drives the disk substrate 15. The spindle motor 17 is housed 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 movement driving device, and can move the spindle motor 17 and the turntable 16 in a predetermined direction in a plane parallel to the main surface of the disk substrate 15. The stage 18 and the turntable 16 are provided with an interferometer, a reflecting mirror, etc., which are a part of the laser distance measuring system 20, in order to measure the distance using the laser light for distance measuring from the light source in the laser distance measuring system 20. Optical elements are arranged. The laser distance measuring system 20 will be described in detail later.

The turntable 16 is made of a dielectric material such as a ceramic substrate and is held by an electrostatic chucking mechanism (not shown). Such an electrostatic chucking mechanism is configured to include a ceramic substrate and an electrode provided in the ceramic substrate and made of a conductor for causing electrostatic polarization. High voltage power supply (not shown) for the electrode
When a positive DC voltage is applied to the electrode from a high voltage power source, electrostatic polarization occurs on the ceramic substrate, and thereby the adsorption force is exerted. That is, by applying a DC voltage, the dielectric (ceramic substrate)
The disk substrate 15 is suction-held by exerting suction force on the disk substrate 15.

Further, the vacuum chamber 11 is provided with a light source 22, a photodetector 23, and a height detector 24 for detecting the height of the main surface of the disk substrate 15. The photodetector 23 is, for example, a position sensor or a CCD (Charge C
Including emitted from the light source 22,
The light beam reflected by the surface of the disk substrate 15 is received, and a light reception signal is supplied to the height detector 24. The height detector 24 detects the height of the main surface of the disk substrate 15 based on the received light signal.

The vacuum chamber 11 is installed via an anti-vibration table (not shown) such as an air damper to suppress the transmission of vibrations from the outside. In addition, the vacuum chamber 11
Is connected to a vacuum pump 28, and the interior of the chamber is set to a vacuum atmosphere of a predetermined pressure by exhausting the inside of the chamber by this. The vacuum chamber 11 is provided with a drive control unit 30 for controlling the rotation and movement drive system. The drive control unit 30 operates under the control of the CPU 25 that controls the entire optical disc master manufacturing apparatus 10. Further, the CPU 25 is connected to a timer device (timer) 26. The drive control unit 30 performs drive control based on the distance measurement data from the laser distance measurement system 20. The drive controller 30 is provided with a radial position detector 35, and detects the position of the electron beam spot in the radial direction based on the distance measurement data. The drive control unit 30 is
It has a feed reference signal generation unit 31 that generates a reference signal of the feed amount of the stage 18, and a spindle reference signal generation unit 32 that generates a reference signal of the rotation amount of the spindle motor 17. A feed control unit 33 that generates a feed control signal based on these reference signals and a spindle control unit 34 that performs spindle control are provided. Also, as described below,
A correction signal generation unit 37 that generates a rotation shake / feed error signal and a correction signal for controlling electron beam deflection is provided.

The electron beam emitting head 40 for emitting an electron beam has an electron gun 41, a converging lens 42, a blanking electrode 43, an aperture 44, a beam deflecting electrode 45,
The focus adjustment lens 46 and the objective lens 47 are arranged in this order in the electron beam emission head unit 40.
The electron beam emission head unit 40 is attached to the ceiling surface of the vacuum chamber 11 with an electron beam emission port 49 provided at the tip of the electron gun barrel 48 facing the space inside the vacuum chamber 11. Further, the electron beam emitting port 49 is arranged facing the main surface of the disk substrate 15 on the turntable 16 so as to face it.

The electron gun 41 emits an electron beam accelerated to several tens KeV by a cathode (not shown) to which a high voltage supplied from the acceleration high voltage power supply 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, controls the blanking electrode 43, and performs on / off control of the electron beam. That is, a voltage is applied between the blanking electrodes 43 to largely deflect the electron beam passing therethrough. As a result, the electron beam is not converged in the aperture hole of the aperture 44, the electron beam is prevented from passing through the aperture 44, and the electron beam can be turned off.

The beam deflection driving unit 55 applies a voltage to the beam deflection electrode 45 to deflect the passing electron beam in response to a control signal from the CPU 25. This allows
The position of the electron beam spot on the disk substrate 15 is controlled. The focus lens drive unit 56 performs focus adjustment of the electron beam spot with which the main surface of the disk substrate 15 is irradiated, based on the detection signal from the height detection unit 24.

The blanking drive unit 54, the electron beam drive unit 57 including the beam deflection drive unit 55 and the focus lens drive unit 56, the accelerating high voltage power supply 51, the laser distance measuring system 20 and the vacuum pump 28 are based on control signals from the CPU 25. Works. Next, the laser distance measuring system 20 for detecting the rotational shake of the turntable 16 will be described in detail. FIG. 2 is a block diagram showing the configuration of the laser distance measuring system 20.

The stage 18 is moved in the vacuum chamber 11 in a predetermined feed direction (x-axis direction in FIG. 2). On the stage 18, the flat reflecting mirror 61
And plane mirror interferometers 62 and 63 are attached. A plane mirror interferometer 64 is attached to the outside of the stage 18 in the vacuum chamber 11. In addition, the vacuum chamber 11
A laser light source 66 and beam splitters 65A to 65D for supplying laser light to the above-mentioned optical elements outside
Are arranged. Laser light is supplied to the interferometers 62, 63, 64 via beam splitters 65D, 65B, 65C, respectively.

The interferometer 62 constitutes a first distance measuring system for detecting the rotational shake of the turntable 16 in the x-axis direction together with a light receiver (receiver) 68. That is, the laser light reflected by the turntable 16 is interferometer 62.
Is detected by the receiver 68 via. The detection signal is supplied to the distance measuring circuit board 70, and distance measuring data in the x-axis direction representing the distance between the turntable 16 and the interferometer 62 is generated. On the other hand, the interferometer 63, together with the receiver 69, is in the direction (y-axis direction) orthogonal to the feed direction of the turntable 16.
For detecting rotational runout of the turntable 16 at
It constitutes the distance measuring system. The detection signal from the receiver 69 is supplied to the distance measuring circuit board 70, and the turntable 16
Distance measurement data in the y-axis direction that represents the distance between the interferometer 63 and The interferometer 64, together with the reflecting mirror 61 and the receiver 67, constitutes a third distance measuring system that detects the amount of movement of the stage 18. The detection signal from the receiver 67 is supplied to the distance measuring circuit board 70, and distance measuring data in the x-axis direction representing the distance between the stage 18 and the interferometer 64 is generated. Further, this movement amount represents the position of the electron beam spot in the x-axis direction. The above interferometer,
Optical elements such as a reflecting mirror, a beam splitter, and a receiver are arranged so that the optical paths of laser light are substantially in the same plane.

As described above, the receivers 67, 68, 6
Each distance measurement data generated in the distance measurement circuit board 70 based on the detection signal from 9 is sent to the correction signal generation unit 37. The correction signal generator 37 generates a correction signal for controlling the deflection of the electron beam, and the beam deflection driver 5
5 is supplied. FIG. 3 is a block diagram showing an example of the correction signal generator 37 and the feed controller 33. The correction signal generation unit 37 has a deflection correction signal generation unit 37A. The deflection correction signal generation unit 37A generates a correction signal for deflection correction of the electron beam using the rotation signal from the spindle motor 17 and the distance measurement data from the laser distance measurement system 20 in the x-axis and y-axis directions. On the other hand, the feed control unit 33 generates a feed control signal using the feed reference signal and the radial position signal indicating the electron beam spot position in the radial direction. For example, in the case of CLV (Consatant Line Velocity) control, a feed reference signal corresponding to the detected radial position is generated, and the feed reference signal and the feed position (distance measurement data from the third distance measurement system described above). The feed control signal is generated so that the error between and becomes zero.

FIG. 4 is a block diagram showing the configuration of the deflection correction signal generator 37A. First, the address data generation unit 72 supplies the encoder pulse signal (n pulses / revolution, for example, 4096 pulses / revolution) indicating the rotation angle of the spindle motor 17 and the encoder pulse reference signal indicating the rotation angle position which is the rotation reference position. (1 pulse / rotation), and the clock signal (CK) of the laser distance measuring system 20 is supplied. The address data generator 72 counts encoder pulses with reference to the encoder pulse reference signal. In order to process data for each predetermined rotation angle, for example, 10 bits (= 102 bits) corresponding to the rotation angle are calculated from the count value.
The address of 4) is generated and supplied to each processing circuit in the deflection correction signal generation unit 37A via the address data bus.

Distance measurement data in the x-axis direction from the laser distance measurement system 20 is fetched by the x-axis data fetching section 73A to generate a displacement amount corresponding to rotational shake in the x-axis direction. In the synchronous / asynchronous component generation circuit 80A, the rotational shake synchronous component in the x-axis direction (hereinafter simply referred to as synchronous component)
And a rotational shake asynchronous component (hereinafter simply referred to as an asynchronous component) are generated. Specifically, the synchronous component of the rotational shake of the turntable 16 is caused by the end surface accuracy and eccentricity of the turntable 16, and the asynchronous component is caused by backlash and vibration. The asynchronous component has a bad influence particularly on the track pitch. Details of the synchronous / asynchronous component generation circuit 80A will be described later.

The asynchronous component generated in the synchronous / asynchronous component generation circuit 80A is digital / analog (D /
A) A converter 77A converts the signal into an analog signal, and a filter and amplification unit 78A having a predetermined band generates a beam deflection correction signal in the x-axis direction. This x-axis direction deflection correction signal is added to the above-mentioned feed control signal in the adder 37B and then supplied to the deflection drive section 55.
The x-axis deflection correction is to correct an error component in a high frequency range that cannot be followed by the above-mentioned feed control by controlling the x-axis beam deflection. That is, stage 1
Beam deflection correction is performed on the high-frequency vibration component and the rotational shake asynchronous component of 8 in the x-axis direction.

As for the distance measurement data in the y-axis direction, the y-axis data fetching section 73B and the synchronous / asynchronous component generating circuit 80
Similar processing is performed in the B, D / A converter 77B and the filter and amplification unit 78B having a predetermined band, and a beam deflection correction signal in the y-axis direction is generated. The y-axis deflection correction signal is supplied to the beam deflection driving section 55, and the beam deflection is corrected for the rotational shake asynchronous component in the y-axis direction.

FIG. 5 is a block diagram showing an example of the configuration of the above-mentioned synchronous / asynchronous component generating circuit 80A. The displacement amount in the x-axis direction (that is, the measured displacement amount this time) supplied from the data acquisition unit 73A is supplied to the weighted average calculation unit 81A. The weighted average calculation unit 81A calculates a weighted average value (weighted average value) of the measured displacement amount and the accumulated displacement amount of this time, and obtains a new accumulated displacement amount. This new accumulated displacement amount is used as a synchronous component of rotational shake.

That is, the accumulated displacement amount from the weighted average calculation unit 81A is 1 in the turntable 16 (that is, the disk substrate 15) in the delay device such as the shift register 86A.
It is delayed by the rotation amount and supplied to the weighted average calculation unit 81A as the accumulated displacement amount. n-stage shift register 86A
Is supplied with the above-described encoder pulse (n pulses / rotation), and the previous accumulated displacement amount is supplied to the weighted average calculation unit 81A in accordance with the pulse signal. The previous cumulative displacement amount is multiplied by a predetermined coefficient (K) in the multiplier 84A. On the other hand, the current measured displacement amount supplied from the data acquisition unit 73A is multiplied by the coefficient (1-K) in the multiplier 84A. The result of these multiplications is the adder 8
In 3A, the weighted average calculation of the measured displacement amount and the accumulated displacement amount of this time is executed, and a new accumulated displacement amount (synchronous component) is obtained. The predetermined coefficient is 0.5 (K =
In the case of 0.5), the weighted average calculation unit 81A calculates the arithmetic mean of the current measured displacement amount and the accumulated displacement amount.

As described above, the new accumulated displacement amount represents the synchronization component. The synchronous component is subtracted from the measured displacement amount at this time by the subtractor 88A to obtain the asynchronous component.
As shown in FIG. 4, as for the distance measurement data in the y-axis direction,
Similar processing is performed to obtain a beam deflection correction signal for the asynchronous component in the y-axis direction. The electron beam deflection control operation will be described in detail below with reference to the flowchart of FIG. For simplicity of description, beam deflection control in the x-axis direction will be described.

First, after the disc substrate 15 is placed at a predetermined position, the disc substrate 15 is rotated (step S1).
01). The x-axis direction distance measurement data is fetched based on the encoder pulse reference signal that is the rotation reference position (step S102), and the displacement amount data B (= B (i), i = 1,2 for one rotation in the x-axis direction). , ...) are stored in the shift register 86A based on the encoder pulse signal (step S103). Next, the displacement amount data C (= C (i), i = 1, 2, ...) For one rotation is further captured. That is, the displacement amount data of this time is fetched (step S1
04).

Next, A = (1−K) × C + K × B is calculated to calculate the weighted average value A of the displacement amounts (step S10).
5) together with the calculated weighted average value A (= A (i), i
= 1, 2 ,. ． ． ) Are sequentially stored in the shift register 86A (step S106). The calculated weighted average value A represents a synchronous component and is used as cumulative displacement amount data (that is, B) for performing a weighted average calculation with the displacement amount data C for the next one rotation. On the other hand, the weighted average value A is subtracted from the current displacement amount data to calculate the asynchronous component (CA) (step S107). A beam deflection correction signal is generated from the asynchronous component (step S108),
The electron beam deflection is controlled based on the deflection correction signal (step S109).

Next, it is judged whether or not the deflection control is continued (step S110). When the deflection control is continued, the process proceeds to step S104 and the above procedure is repeated. When it is determined in step S110 that the deflection control is not continued, the control returns to the main routine.
Similar processing is performed for the beam deflection control in the y-axis direction. The deflection of the electron beam is controlled by this procedure.

Therefore, according to the present invention, since the synchronous component is updated for each rotation, the control error can be reduced and a highly accurate manufacturing apparatus can be realized. Further, the required memory capacity is small, and it is possible to realize a high-precision disc master manufacturing apparatus capable of correcting rotational shake in real time with a simple configuration. Although the optical disk master has been described as an example of the disk master, the present invention is not limited to this and can be applied to an apparatus for manufacturing a magnetic disk master or the like by using an electron beam.

[0032]

As is apparent from the above, according to the present invention, it is possible to realize an apparatus capable of manufacturing a high-density and high-precision disc master by eliminating adverse effects due to rotational shake and displacement of the disc substrate. .

[Brief description of drawings]

FIG. 1 is a block diagram showing a disk master manufacturing apparatus using an electron beam according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a laser distance measuring system of the disc master manufacturing apparatus shown in FIG.

FIG. 3 is a block diagram showing an example of a correction signal generation unit and a feed control unit.

FIG. 4 is a block diagram showing a configuration of a deflection correction signal generation unit.

FIG. 5 is a block diagram showing an example of a configuration of a synchronous / asynchronous component generation circuit.

FIG. 6 is a flowchart showing a procedure of an electron beam deflection control operation.

[Explanation of symbols for main parts]

10 Disc master manufacturing equipment 15 disk substrate 16 turntable 17 Spindle motor 19 Feed motor 20 Laser distance measuring system 25 CPU 30 Drive control unit 35 Radius position detector 37 Correction signal generator 40 Electron beam injection head 45 beam deflection electrode 55 Beam deflection driver 61 Reflector 62, 63, 64 interferometer 67,68,69 Receiver 70 Distance measuring circuit board 80A, 80B Synchronous / asynchronous component generation circuit 81A Weighted average calculator 82A, 84A multiplier 83A adder 86A shift register 88A subtractor

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroki Kaneda             Pioneer, 465 Osato-cho, Kofu City, Yamanashi Prefecture             Within the corporation (72) Inventor Kenji Uemura             Pioneer, 465 Osato-cho, Kofu City, Yamanashi Prefecture             Within the corporation (72) Inventor Masaki Sone             Pioneer, 465 Osato-cho, Kofu City, Yamanashi Prefecture             Within the corporation (72) Inventor Kazumi Kuriyama             Pioneer, 465 Osato-cho, Kofu City, Yamanashi Prefecture             Within the corporation F term (reference) 2F069 AA06 AA21 BB17 CC07 DD21                       GG04 GG07 GG12 GG58 GG74                       HH09 HH15 JJ17 KK10 MM02                       MM23 NN08 NN26 PP02                 2H097 AA03 AB07 BA01 BA02 BA10                       CA16 KA01 KA29 KA38 LA20                 5D121 BB01 BB21 BB38 BB40

Claims (4)

[Claims] 1. An apparatus for manufacturing a disc master by irradiating a substrate with an electron beam, the electron beam emitting unit emitting the electron beam, a deflection driving unit performing deflection control of the electron beam, and the substrate. A rotation driving unit that rotationally drives the electron beam emitting unit and a movement driving unit that relatively moves the electron beam emitting unit and the substrate in a predetermined direction within a plane parallel to the main surface of the substrate; A distance measuring device that measures the displacement amount in a predetermined direction, and a weighted average value of the displacement amount measured this time by the distance measuring device and the accumulated displacement amount is calculated. At the time of this calculation, the weighted average value of the substrate before one rotation is calculated. Calculating the weighted average value using the value as the accumulated displacement amount, and generating an asynchronous component by subtracting the weighted average value from the measured displacement amount of this time as an asynchronous component generator; A control unit forming the irradiation position adjustment of said electron beam by controlling the deflection driving section based on,
An apparatus comprising: 2. The range finder measures the displacement amount for each predetermined rotation angle of the substrate, and the asynchronous component generator generates an asynchronous component for each predetermined rotation angle. The described device. 3. The weighted average circuit for calculating a weighted average value of the current measured displacement amount and the accumulated displacement amount by the rangefinder, and the weighted average value for one rotation of the substrate. 3. A delay circuit for outputting a delayed one as the accumulated displacement amount, and a subtraction circuit for subtracting the weighted average value from the measured displacement amount at this time to generate an asynchronous component. The described device. 4. The range finder has a first range finder for measuring a displacement amount of the substrate in the predetermined direction and a second range finder for measuring a displacement amount of the substrate in a direction orthogonal to the predetermined direction. The asynchronous component generator generates an asynchronous component in the predetermined direction based on the displacement amount measured by the first distance measuring device and moves in the predetermined direction based on the displacement amount measured by the second distance measuring device. An apparatus as claimed in claim 1, characterized in that it produces asynchronous components in orthogonal directions.