JPH11288530A - Pattern plotting method using electron beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a disk original plate having a precise and fine pattern by properly plotting a desired pattern to a resist material applied onto a substrate to be rotatively operated through electron beams. SOLUTION: The current density J being the size of a current per the unit area of electron beams is set to satisfy J>=A×S/ P×1 [h]×π⊗W} at the time of setting the area of the recording area of an optical recording medium to be A, the track pitch of the optical recording medium to be P, an electric charge quantity per the unit area to be required for plotting a chemical amplifying type resist 2 to be S and the radius of the spot of the electron beams to be irradiated to the resist 2 to be W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of irradiating an electron beam emitted from an electron gun onto a chemically amplified resist coated on a substrate to form a pattern corresponding to a pattern of a recording medium on the chemically amplified resist. The present invention relates to a pattern drawing method using an electron beam to be drawn.

[0002]

2. Description of the Related Art In recent years, information recording media such as optical disks have been rapidly improved in recording density, and patterns such as pits and grooves have been miniaturized. In order to accurately produce such a fine pattern, there has been proposed a technique for producing a master disc by drawing a pattern using an electron beam as in a semiconductor fabrication process.

Since the wavelength of an electron beam is shorter than that of light and the diffraction phenomenon can be neglected, a fine pattern can be formed by using an electron beam lithography apparatus used in a semiconductor manufacturing process for manufacturing a master disk. It is possible to draw with high accuracy.

[0004]

When a pattern is drawn using an electron beam in a semiconductor manufacturing process, the electron beam is irradiated while being electromagnetically deflected onto a wafer or a photomask placed on a support table. Is done.
Therefore, the electron beam writing apparatus used in the semiconductor manufacturing process is set to an optimal state for irradiating an electron beam onto a wafer or a photomask placed on a support while electromagnetically deflecting the electron beam.

On the other hand, when a master disc is manufactured, it is necessary to irradiate an electron beam onto a resist material applied on a substrate rotating at a high speed of about 500 to 2500 rpm, so that it is used in a semiconductor manufacturing process. It is difficult to use the electron beam lithography apparatus that has been used for producing a master disk as it is.

[0006] For example, an electron beam is emitted from 500 to 2500.
When irradiating a resist layer on a substrate rotating at a high speed of about rpm, the linear velocity of an electron beam irradiation spot is 1
５5 m / sec. Therefore, in order to irradiate the resist material coated on this substrate with an electron beam and draw an appropriate pattern, the current density, which is the magnitude of the current per unit area of the electron beam, is set to a value corresponding to this linear velocity. Must be set to

Further, if the drawing time is long, it is difficult to maintain the stability of the electron beam, and the beam may fluctuate. For this reason, one disk master must be manufactured within the time that the stability of the electron beam can be maintained. It is necessary to control the drawing time so that the drawing for the drawing is completed.

[0008] In view of the above, an object of the present invention is to appropriately draw a desired pattern on a resist material applied on a substrate which is rotated by using an electron beam, thereby producing a master disk having a highly accurate fine pattern. An object of the present invention is to provide a pattern drawing method using a possible electron beam.

[0009]

A pattern drawing method using an electron beam according to the present invention comprises irradiating an electron beam emitted from an electron gun onto a chemically amplified resist applied on a substrate to be rotated. When drawing a pattern corresponding to the pattern of the recording medium on this chemically amplified resist,
The current density J, which is the magnitude of the current per unit area of the electron beam, the area of the recording area of the recording medium is A, the track pitch of the recording medium is P, and the drawing of the chemically amplified resist is required. When the charge amount per unit area is S and the radius of the spot of the electron beam irradiated on the chemically amplified resist is W, J ≧ A × S / (1 [h] ×
π × P × W).

[0010] The current density is set so as to satisfy the above equation, and a pattern corresponding to the pattern of the recording medium is drawn on the chemically amplified resist applied on the substrate to be rotated. Pattern writing can be performed at a current density corresponding to the linear velocity of the irradiation spot, and a master disk having a fine pattern can be manufactured with high accuracy.

Further, in the pattern drawing method using an electron beam according to the present invention, an aperture is arranged on a path of the electron beam toward the chemically amplified resist, and an electric field or an electric field is provided on a path of the electron beam toward the chemically amplified resist. It is desirable that the intensity of the electron beam be modulated by switching whether or not the electron beam passes through the aperture by applying a magnetic field to deflect the electron beam.

If the intensity of the electron beam is modulated as described above, the on / off switching of the electron beam can be easily performed, and a desired pattern can be easily drawn.

Further, in the pattern writing method using an electron beam according to the present invention, when writing a pattern corresponding to the shortest pit of the recording medium, when the pit length of the shortest pit is L, A / A
It is desirable to perform at a frequency of (2 [h] × P × L) or more.

The intensity modulation of the electron beam is represented by A / (2 [h] ×
By drawing a pattern corresponding to the shortest pit of the recording medium at a frequency equal to or higher than P × L), a desired pattern can be drawn with high accuracy.

Further, in the pattern writing method using an electron beam according to the present invention, when a pattern corresponding to a pattern of a recording medium having a meandering pattern is drawn, the pattern of the electron beam toward the chemically amplified resist is used. It is desirable to draw a meandering pattern on the chemically amplified resist by deflecting the electron beam by applying an electric or magnetic field.

By drawing a meandering pattern by deflecting the electron beam as described above, a master disk having a meandering pattern can be manufactured with high accuracy.

Further, in the pattern writing method using an electron beam according to the present invention, when the electron beam is irradiated on the chemically amplified resist, a voltage applied to accelerate the electron beam is 30 to 30. It is desirable to set it in the range of 80 kV.

By setting the voltage applied for accelerating the electron beam as described above, pattern deterioration due to forward scattering of the electron beam does not occur, and the sensitivity of the chemically amplified resist is lowered. Thus, a desired pattern can be appropriately drawn.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

When an optical recording medium (hereinafter, referred to as an optical disk) such as an optical disk or a magneto-optical disk is manufactured by injection molding, an original disk on which an inverted pattern of pits or grooves of the optical disk is formed is used.

The master disc is mounted in a cavity between a pair of molds provided in the injection molding machine. Then, the molten substrate material is injected into the cavity of the injection molding machine on which the disk master is mounted, and cooled,
A disk substrate on which desired pits and grooves are formed in advance is manufactured. The optical disk is placed on this disk substrate
It is manufactured by sequentially forming a recording layer, a protective layer, and the like.

According to the present invention, as described above, when producing a master disc used in the optical disc producing process,
The pattern is drawn using an electron beam.

When manufacturing a master disc, first, FIG.
As shown in (1), for example, a disk-shaped substrate 1 made of glass or the like whose surface is precisely polished is prepared.

Next, as shown in FIG. 2, a chemically amplified resist 2 is applied to the main surface of the substrate 1 via an adhesion reinforcing agent or the like to form a resist layer. The chemically amplified resist 2 is a resist material having high sensitivity and high resolution and suitable for drawing a pattern using an electron beam.

Next, the substrate 1 on which the chemically amplified resist 2 has been applied is set in an electron beam lithography apparatus described later.
Rotated. Then, as shown in FIG. 3, by irradiating the chemically amplified resist 2 with an electron beam, a pattern corresponding to the pits and grooves of the optical disk is drawn on the chemically amplified resist 2 in, for example, a spiral shape. You. Then, the chemically amplified resist 2 irradiated with the electron beam is baked (PEB: Post Exposure).
As a result, a latent image of a concavo-convex pattern corresponding to pits and grooves of the optical disk is formed on the chemically amplified resist 2.

Next, the chemically amplified resist 2 on which the latent image is formed is developed with an alkaline developing solution, and as shown in FIG. 4, a resist master 3 having a concavo-convex pattern corresponding to the pits and grooves of the optical disk is formed. It is formed.

Next, as shown in FIG.
The metal film 4 such as silver or nickel is formed on the main surface having the uneven pattern by a method such as a sputtering method, a vapor deposition method, and an electroless plating method.

Next, the resist master 3 on which the metal coating 4 is formed is set in an electroplating apparatus, and electroplating is performed using the metal coating 4 as an electrode, as shown in FIG. The electroplating layer 5 is formed on the main surface of the substrate 1 via the metal coating 4.

Next, as shown in FIG. 7, the resist master 3 is peeled off from the electroplating layer 5 to which the metal film 4 has adhered. Then, the excess metal film 4 is removed by pressing from the electroplated layer 5 from which the resist master 3 has been peeled off, thereby completing a disk master 6 as shown in FIG.

On the disk master 6 manufactured as described above, the electron beam is irradiated onto the chemically amplified resist 2 applied on the substrate 1 to be rotated while modulating the intensity of the electron beam according to the modulation signal. As a result, a pattern 11 corresponding to the pit pattern of the optical disk as shown in FIG. 9 is formed.

Further, the disk master 6 manufactured as described above is irradiated with the electron beam while deflecting the chemically amplified resist 2 applied on the substrate 1 to be rotated in accordance with the deflection signal. As a result, a pattern 12 corresponding to the meandering groove (wobbling groove) pattern of the optical disc as shown in FIG. 10 is formed.

Further, the disk master 6 manufactured as described above is irradiated with the electron beam as a fixed beam without deflecting the electron beam onto the chemically amplified resist 2 applied on the substrate 1 to be rotated. Thus, as shown in FIG.
Linear groove of optical disk (straight groove)
The pattern 13 corresponding to this pattern is formed.

Here, the chemically amplified resist 2 applied on the substrate 1 is irradiated with an electron beam, and a pattern corresponding to the pit or groove pattern of the optical disk is drawn on the chemically amplified resist 2. The electron beam writing apparatus will be described.

As shown in FIG. 12, the electron beam writing apparatus 20 includes an electron beam generator 3 for generating an electron beam.
0, an electron beam focusing unit 40 that focuses the electron beam from the electron beam generating unit 30 and irradiates the electron beam onto the chemically amplified resist 2 coated on the substrate 1, and the substrate 1 coated with the chemically amplified resist 2. A substrate supporting mechanism 50 movably supporting the substrate.

In the electron beam writing apparatus 20,
The electron beam generating unit 30 and the electron beam converging unit 40 are disposed in the electron optical column 21 maintained in a high vacuum state.

The electron optical column 21 has, for example, a cylindrical shape, and is provided on the vibration isolation table 23 so that one end thereof faces the substrate 1 supported by the substrate supporting mechanism 50 disposed in the atmosphere. Is held by the holder 22 provided.
An electron beam transmission hole (not shown) is provided at an end of the electron optical lens barrel 21 facing the substrate in a portion serving as an electron beam path.
It is closed by a thin film (not shown) that sufficiently transmits the electron beam. In the electron beam exposure apparatus 20, this thin film functions as a vacuum shield for the electron optical column 21.

On the other hand, the substrate supporting mechanism 50 is placed on the vibration isolation table 23 and supports the substrate 1 on which the chemically amplified resist 2 has been applied at atmospheric pressure.

The electron beam writing apparatus 20 includes an electron beam generating section 30, an electron beam focusing section 40, and a substrate supporting mechanism section 5.
0 are supported by the vibration isolation table 23,
Draw defects due to external vibrations are suppressed.

The electron beam generator 30 includes an electron gun 31 for emitting an electron beam, a condenser lens 32 for focusing the electron beam emitted from the electron gun 31, and a modulation signal for the electron beam focused by the condenser lens 32. Electron beam modulating means 33 for deflecting or passing according to
And an aperture 34 for transmitting or blocking an electron beam deflected by the electron beam modulation means 33 or passed through the electron beam modulation means 33.

The electron gun 31 emits an electron beam emitted from an electron beam emission source such as LaB _{6 and} accelerated by an anode. The electron beam emitted from the electron gun 31 is focused by a condenser lens 32 which is an electrostatic lens, and is transmitted through an electron beam modulating unit 33 to the aperture 1.
Reach 4

The electron beam modulating means 33 includes a pair of electrodes 3
3a and 33b, which switch on / off by generating an electric field between these electrodes according to the modulation signal and deflecting the electron beam focused by the condenser lens 32. That is, when turning off the electron beam, the electron beam modulating means 33 generates a large electric field between the pair of electrodes so that the electron beam focused by the condenser lens 32 is blocked by the aperture 34, Large deflection. When turning on the electron beam, the electron beam modulating means 33 passes the electron beam without deflecting it so that the electron beam focused by the condenser lens 32 passes through the aperture 34. Here,
Although an example in which the electron beam modulating means 33 is configured to generate an electric field in the path of the electron beam to deflect the electron beam has been described, the electron beam modulating means 33 is not limited to this example. Alternatively, a configuration may be adopted in which a magnetic field is generated in the path of the electron beam to deflect the electron beam.

The electron beam transmitted through the aperture 34 moves to the electron beam focusing section 40 in a state where the beam diameter is narrowed by the aperture 34.

The electron beam focusing section 40 deflects the electron beam transmitted through the aperture 34 of the electron beam generating section 30 in accordance with a wobbling signal.
A focus adjusting lens 42 for adjusting the beam diameter of the electron beam deflected by the electron beam deflecting means 41 or passing through the electron beam deflecting means 41; and focusing the electron beam whose beam diameter is adjusted by the focus adjusting lens 42. Objective lens 43 for irradiating chemically amplified resist 2
And

The electron beam deflecting means 41 includes a pair of electrodes 4
1a and 41b, an electric field is generated between these electrodes according to the wobbling signal to deflect the electron beam transmitted through the aperture 34.
This is for forming the pattern 12 corresponding to the wobbling groove as shown in FIG. Therefore, the electron beam deflecting means 41 deflects the electron beam only when the pattern 12 corresponding to the wobbling groove is formed, for example, and the pattern 11 corresponding to the pit as shown in FIG. When a pattern 13 corresponding to a straight groove as shown in FIG. 11 is formed, the electron beam is allowed to pass without being deflected. Here, an example is described in which the electron beam deflector 41 is configured to deflect the electron beam by generating an electric field in the path of the electron beam. However, the electron beam deflector 41 is not limited to this example. Is not
The magnetic field may be generated in the path of the electron beam to deflect the electron beam.

The spot diameter of the electron beam transmitted through the electron beam deflecting means 41 is adjusted by a focus adjustment lens 42 composed of an electrostatic lens or an electromagnetic lens. The electron beam is always focused on the chemically amplified resist 2 by passing through the focus adjustment lens 42. The electron beam whose spot diameter has been adjusted by the focus adjustment lens 42 enters the objective lens 43.

The electron beam incident on the objective lens 43 is
Focused by this objective lens 43, several nm to several μm
And irradiates the chemically amplified resist 2 on the substrate 1 supported by the substrate support mechanism 50.

The substrate support mechanism 50 includes an air spindle device 51 for rotating the substrate 1 on which the chemically amplified resist 2 has been applied, and an air spindle device 51 for rotating the substrate 1 shown in FIG.
2, an air slide device 52 for horizontally moving the substrate 1 in the radial direction indicated by the arrow A in FIG.

The air spindle device 51 includes a stage on which the substrate 1 coated with the chemically amplified resist 2 is mounted,
An air bearing that supports a rotating shaft attached to the stage and a drive motor that rotates the stage are provided, and are driven at a rotational speed controlled with high precision. For example, the air spindle device 51 rotates the substrate 1 coated with the chemically amplified resist 2 at 3600 rpm,
The rotation speed is controlled by a servo mechanism using, for example, an optical rotary encoder with a rotation jitter of 10 ^-7 or less per rotation.

The air slide device 52 uses a drive motor for moving the air spindle device 51 in the radial direction A of the substrate 1 and air for supporting the air spindle device 51 and controlling the horizontal movement of the air spindle device 51. Linear guide mechanism. The moving speed of the air slide device 52 is precisely controlled by, for example, a length measuring mechanism using a laser scale.
Horizontally in the radial direction A.

The electron beam focused by the objective lens 43 is irradiated on the chemically amplified resist 2 on the substrate 1 which is rotated by the air spindle device 51 and horizontally moved by the air slide device 52. As a result, a latent image having a pattern corresponding to the pits and grooves of the optical disk is formed in the chemically amplified resist 2 in a spiral shape, for example.

When a predetermined pattern is drawn on the chemically amplified resist 2 using the electron beam drawing apparatus 20 described above, the electron beam is applied to the substrate 1 which is rotated at a high speed by the air spindle device 51. Irradiation is performed on the chemically amplified resist 2. Therefore, in order to draw an appropriate pattern on the chemically amplified resist 2, the current density, which is the magnitude of the current per unit area of the electron beam emitted from the electron gun 31, is changed to a value corresponding to this linear velocity. Must be set.

Here, assuming that the area of the recording area of the optical disk to be manufactured is A and the track pitch of the recording track of the optical disk is P, the total length of the recording track of the optical disk can be represented by A / P.

When writing a pattern on the master disk corresponding to this optical disk, the linear velocity V of the spot of the electron beam is a value obtained by dividing the total track length A / P by the time t required for writing.

Here, the time t required for drawing needs to be within 2 hours in consideration of the stability of the electron beam, the stability of the chemically amplified resist 2, the practical productivity of the master disk 6, and the like. It is.

The stability of the chemically amplified resist 2 depends on the progress of the dark reaction that occurs between the irradiation of the chemically amplified resist 2 with the electron beam and the above-described baking after drawing (PEB). Chemically amplified resist 2
Generally, a latent image is formed by activating the acid generated in the resist by irradiation with an electron beam by PEB. However, the acid component generated by the irradiation of the electron beam is gradually deactivated by the amine component contained in a slight amount in the atmosphere around the chemically amplified resist 2, and a so-called dark reaction occurs.

Therefore, if a long time elapses between the start of drawing and the end of drawing, the dark reaction of the chemically amplified resist 2 proceeds, and the pattern formed after PEB is performed. However, the pattern at the start of the drawing and the pattern at the end of the drawing are greatly different, and appear as a pattern variation.

The time from the start of drawing to PEB is generally referred to as PED (Post Exposure Delay), and when a pattern is formed by irradiating the chemically amplified resist 2 with an electron beam, the pattern to be formed is formed. In order to make the fluctuation small enough to be ignored, it is desirable that the PED be set within two hours.

For the above reasons, if the time required for writing is set within 2 hours, the linear velocity of the spot of the electron beam V
Can be represented by the following equation (1).

V ≧ A / (2 [h] × P) (1) The current I of the electron beam necessary to form an appropriate pattern corresponding to the linear velocity V is a chemically amplified type. Resist 2
Assuming that the amount of charge per unit area required for the writing of S is S and the radius of the spot of the electron beam irradiated on the chemically amplified resist 2 is W, the following equation (2) can be obtained.

I = 2 × W × V × S (2) The current density J, which is the magnitude of the current per unit area of the electron beam, can be expressed by the following equation (3). .

J = I / (π × W ² ) (3) When the above equation (2) is substituted into the above equation (3), the following equation (4) is obtained.

J = 2 × V × S / (π × W) (4) By substituting the above equation (1) into the above equation (4), the following equation (5) is obtained.

J ≧ A × S / (1 [h] × π × P × W) (5) As described above, the electron beam is applied to the chemically amplified resist 2 to support the optical disk. When a pattern is formed, the current density J, which is the magnitude of the current per unit area of the electron beam, is set so as to satisfy the above equation (5), so that the electron beam is applied onto the substrate 1 to be rotated. A desired pattern can be appropriately drawn on the chemically amplified resist 2 and the master disk 6 having a highly accurate fine pattern can be manufactured.

Further, using the electron beam writing apparatus 20,
As described above, in order to produce the pattern 11 corresponding to the pits of the optical disk shown in FIG. 9, a voltage (modulation signal) of a predetermined frequency is applied between the pair of electrodes 33a and 33b of the electron beam modulation means 33 as described above. Is applied, the electron beam is deflected and cut off by the aperture 34, or the electron beam is passed as it is and transmitted through the aperture 34 to switch on / off the electron beam.

Also in this case, since the electron beam is applied to the chemically amplified resist 2 on the substrate 1 which is rotated at a high speed by the air spindle device 51, the pattern corresponding to the pits of the optical disk is added to the chemically amplified resist 2. In order to draw 11 properly, the frequency of the voltage applied between the pair of electrodes 33a and 33b of the electron beam modulating means 33 should be
It is necessary to set a value corresponding to the linear velocity of the spot of the electron beam.

Here, assuming that the shortest pit length of the optical disk to be manufactured is L, the frequency Q of the applied voltage for appropriately drawing the pattern 11 corresponding to the pit of the optical disk corresponding to the linear velocity of the spot of the electron beam. Can be represented by the following equation (6).

Q = V / L (6) When the above equation (1) is substituted into the above equation (6), the following equation (7) is obtained.

Q ≧ A / (2 [h] × P × L) (7) Accordingly, the pattern 11 corresponding to the pits of the optical disk previously shown in FIG.
If the frequency of the voltage applied between the pair of electrodes 33a and 33b of the electron beam modulating means 33 is set so as to satisfy the above equation (7), it corresponds to the linear velocity of the spot of the electron beam. Thus, the pattern 11 corresponding to the pits of the optical disk can be appropriately drawn.

Further, using the electron beam writing apparatus 20,
As described above, in order to produce the pattern 12 corresponding to the wobbling groove of the optical disk shown in FIG.
It is necessary to apply a voltage (wobbling signal) having a predetermined amplitude between 41b, deflect the electron beam, and irradiate the chemically amplified resist 2 on the substrate 1, which is rotated at high speed, in a meandering manner.

In this case, the meandering amplitude of the electron beam on the chemically amplified resist 2, that is, the scanning range of the electron beam, should be set as small as possible to increase the current density and the electron beam modulation means. It is easy to improve the frequency of the voltage applied between the pair of electrodes 33a and 33b.

Here, generally, the meandering amplitude of the wobbling groove of the optical disk is set within 10 μm. For this reason, when a master of an optical disc is manufactured using the electron beam drawing apparatus 20, it does not make much sense to set the scanning range of the electron beam on the chemically amplified resist 2 to 10 μm or more. Therefore, the amplitude of the voltage applied between the pair of electrodes 41a and 41b of the electron beam deflecting means 41 is within the scanning range of the electron beam on the chemically amplified resist 2, that is, the meandering amplitude of the pattern to be drawn is within 10 μm. It is desirable that the setting is made as follows.

When a desired pattern is drawn on the chemically amplified resist 2 using the electron beam drawing apparatus 20,
In order to draw a fine pattern with high accuracy, an electron gun 3
It is desirable that the voltage applied to accelerate the electron beam emitted from 1 is also set to an appropriate value.

When the voltage applied to accelerate the electron beam emitted from the electron gun 31 is set to 30 kV or less, the speed at which the electron beam enters the chemically amplified resist 2 is low, The spread of the electron beam in the amplification type resist 2, that is, the influence of forward scattering becomes large, and the pattern to be formed fluctuates.

If the voltage applied to accelerate the electron beam emitted from the electron gun 31 is set to 80 kV or more, the sensitivity of the chemically amplified resist 2 is reduced, and it is difficult to form an appropriate pattern. Becomes

Therefore, when a desired pattern is drawn on the chemically amplified resist 2 using the electron beam drawing apparatus 20, the voltage applied to accelerate the electron beam emitted from the electron gun 31 must be 30 to 80 kV. It is desirable to set in the range.

Here, the above-described electron beam writing apparatus 20
A signal having a capacity of 30 GB was recorded on one side of a disc having a diameter of 12 cm, the same as a CD (Compact Disc), using
Master disk 6 of read-only ROM type optical disk
In actuality, the current density J, which is the magnitude of the current per unit area of the electron beam emitted from the electron gun 31, and the pair of electrodes 33a,
A description will be given of what value should be set for the frequency Q of the voltage applied between 33b.

30 GB on one side of a 12 cm diameter disc
In order to record the pit pattern with the EFM method similar to the CD recording method, a fine pit pattern having a track pitch P of 0.29 [μm] and a shortest pit length L of 0.16 [μm] is formed with a radius of 24-58. It is necessary to record spirally in an annular recording area in the range of [mm]. At this time, the area A of the recording area is (58 ² −2 ² ) π [mm ² ].

Here, as the chemically amplified resist 2 to be irradiated with an electron beam, a resist having a charge amount S per unit area required for drawing of 5 [μc / cm ² ] was used. The spot size radius W of the electron beam was set to 0.05 [μm].

At this time, the current density J capable of appropriately drawing the above-described fine pattern corresponding to the linear velocity of the spot of the electron beam can be obtained by substituting the above numerical values into the above equation (5). 267 [A / cm ² ] or more.

The frequency Q of the voltage applied between the pair of electrodes 33a and 33b of the electron beam modulating means 33 is about 26 [MHz] by substituting the above numerical values into the above equation (7).
That is all.

In other words, by using the electron beam drawing apparatus 20, an electron beam having a spot radius W of 0.05 [μm] is charged at a charge amount S per unit area required for drawing of 5 [μc / cm]. ² ], a desired pattern is drawn by irradiating the chemically amplified resist 2 with a master disc 6
Is manufactured, the current density J is set to about 267 [A / cm ² ].
As described above, the pair of electrodes 33a, 3
By setting the frequency Q of the voltage applied between 3b to about 26 [MHz] or more, a read-only ROM-type optical disc in which a signal having a capacity of 30 GB is recorded on one side of a disc having the same diameter of 12 cm as a CD. The master disc 6 can be manufactured.

[0082]

According to the pattern writing method using an electron beam according to the present invention, the current density which is the magnitude of the current per unit area of the electron beam is set to a value corresponding to the linear velocity of the spot of the electron beam. Therefore, a desired pattern can be appropriately drawn on a chemically amplified resist applied on a substrate to be rotated and a master disk having a highly accurate fine pattern can be manufactured.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a process of manufacturing a master disc, and is a perspective view of a substrate.

FIG. 2 is a diagram illustrating a process of manufacturing a master disc, and is a perspective view of a substrate on which a chemically amplified resist is applied.

FIG. 3 is a diagram illustrating a process of manufacturing a master disc, and is a perspective view illustrating a state where a pattern is drawn on a chemically amplified resist using an electron beam.

FIG. 4 is a diagram for explaining a process of manufacturing a disc master, and is a cross-sectional view of a main part of a resist master;

FIG. 5 is a diagram illustrating a process of manufacturing a disk master, and is a cross-sectional view of a main part of a resist master on which a metal film is formed.

FIG. 6 is a view for explaining a step of manufacturing a disc master, and is a cross-sectional view of a main part of a resist master on which an electroplating layer is formed.

FIG. 7 is a view for explaining a step of manufacturing the disc master, and is a cross-sectional view of a main part showing a state where the resist master has been peeled off from the electroplating layer.

FIG. 8 is a view for explaining a step of manufacturing the disc master, and is a cross-sectional view of a main part of the disc master.

FIG. 9 is a perspective view of a main part of a master disc on which patterns corresponding to pits of the optical disc are formed.

FIG. 10 is a perspective view of a main part of a disc master on which a pattern corresponding to a wobbling groove of the optical disc is formed.

FIG. 11 is a perspective view of a main part of a disc master on which a pattern corresponding to a straight groove of the optical disc is formed.

FIG. 12 is a configuration diagram illustrating an example of an electron beam writing apparatus.

[Description of Signs] 1 substrate, 2 chemically amplified resist, 6 disk master, 20 electron beam drawing apparatus, 30 electron beam generator, 31 electron gun, 33 electron beam modulating means, 34
Aperture, 40 electron beam focusing section, 41 electron beam deflecting means, 43 objective lens, 50 substrate support mechanism section

Claims (5)

[Claims] An electron beam emitted from an electron gun is applied to a chemically amplified resist applied on a substrate to be rotated to draw a pattern corresponding to a pattern of a recording medium on the chemically amplified resist. In this case, the current density J, which is the magnitude of the current per unit area of the electron beam, is A, the recording area of the recording medium is P, the track pitch of the recording medium is P, and the drawing of the chemically amplified resist is necessary. Where S is the charge amount per unit area, and W is the radius of the spot of the electron beam applied to the chemically amplified resist, wherein the following formula is satisfied. A pattern drawing method using an electron beam. J ≧ A × S / (1 [h] × π × P × W) 2. An aperture is disposed on a path of the electron beam toward the chemically amplified resist, and an electric field or a magnetic field is applied to a path of the electron beam toward the chemically amplified resist to deflect the electron beam. 2. The pattern drawing method using an electron beam according to claim 1, wherein the intensity of the electron beam is modulated by switching whether or not the electron beam passes through the aperture. 3. When drawing a pattern corresponding to the shortest pit of the recording medium, the pit length of the shortest pit is set to L.
, The intensity modulation of the electron beam is A / (2
3. The pattern drawing method using an electron beam according to claim 2, wherein the pattern writing is performed at a frequency of [h] × P × L) or more. 4. A meandering pattern is drawn on the chemically amplified resist by applying an electric field or a magnetic field to a path of the electron beam toward the chemically amplified resist and deflecting the electron beam. Item 7. A pattern drawing method using the electron beam according to Item 1. 5. A voltage applied to accelerate the electron beam when irradiating the chemically amplified resist with the electron beam is set in a range of 30 to 80 kV. Item 7. A pattern drawing method using the electron beam according to Item 1.