WO2010023751A1

WO2010023751A1 - Method for adjusting electron beam plotting device and method for adjusting control device for controlling electron beam plotting device

Info

Publication number: WO2010023751A1
Application number: PCT/JP2008/065506
Authority: WO
Inventors: 寛顕鈴木; 章雄福島; 孝幸糟谷; 聡杉浦
Original assignee: パイオニア株式会社
Priority date: 2008-08-29
Filing date: 2008-08-29
Publication date: 2010-03-04

Abstract

An electron beam plotting device to be adjusted is caused to plot a predetermined test pattern. According to an image expressing the plotted test pattern, correction data for correcting a control amount of a plotting control unit is generated in the electron beam plotting device. According to the correction data, the control amount of the plotting control unit is corrected in the electron beam plotting device.

Description

Method for adjusting electron beam drawing apparatus and method for adjusting control apparatus for controlling electron beam drawing apparatus

The present invention relates to adjustment of an electron beam drawing apparatus that performs pattern drawing by irradiating an electron beam.

Magnetic disks or hard disks (HD) are used in personal computer (PC) storage devices, mobile devices, in-vehicle devices, and the like. In recent years, the application has been remarkably expanded and the surface recording density has been rapidly improved.

In order to manufacture such a high recording density hard disk, an electron beam mastering technique using an electron beam recording apparatus has been studied (for example, see Patent Document 1). An electron beam recording apparatus includes an electron gun that emits electrons, an electron lens that irradiates a substrate coated with a resist with an electron beam that converges the electrons, and blanking and beam deflection driving that control the irradiation position of the electron beam. System. At this time, a latent image is drawn on the resist where the electron beam is irradiated.

Here, as a high-density hard disk, groove tracks such as Discrete Track Media (DTM) and Bit Patterned Media (BPM) are formed concentrically on the disk surface. What has been attracting attention. Therefore, in order to manufacture a hard disk having such a groove-like track, an electron beam recording apparatus is required to draw a concentric latent image corresponding to the track with high accuracy. Furthermore, the electron beam recording apparatus is required to accurately draw latent images corresponding to pits and marks having various shapes.
JP 2002-367178 A

In the present invention, an adjustment method of an electron beam drawing apparatus that enables drawing to be performed with an original drawing accuracy or drawing ability, and an adjustment method of a control device that controls the electron beam drawing apparatus are provided. With the goal.

The method of adjusting an electron beam lithography apparatus according to claim 1 is an adjustment method of an electron beam lithography apparatus that performs pattern drawing by irradiating an electron beam onto a resist coated on a surface of a substrate, wherein the electron beam lithography apparatus A test pattern drawing process for drawing a predetermined test pattern, a test pattern drawing image acquisition process for obtaining a test pattern drawing image, and a control amount of a drawing control unit in the electron beam drawing apparatus based on the test pattern drawing image A correction data generation process for generating correction data to be corrected; and a correction process for correcting the control amount of the drawing control unit in the electron beam drawing apparatus based on the correction data.

According to a seventh aspect of the present invention, there is provided an adjustment method for a control device for controlling an electron beam drawing apparatus, which is responsible for drawing control of an electron beam drawing apparatus that performs pattern drawing by irradiating an electron beam onto a resist applied to a surface of a substrate. An adjustment method of a control device for generating a drawing control signal, comprising: a step of performing control for causing the electron beam drawing device to draw a predetermined test pattern; and the test pattern drawn by the electron beam drawing device. A step of generating correction data representing a correction amount for the drawing control signal based on the test pattern drawing image to be represented, and a step of correcting the drawing control signal based on the correction amount represented by the correction data. .

A control device for controlling an electron beam lithography apparatus according to claim 9 is a control device for controlling an electron beam lithography apparatus that performs pattern drawing by irradiating an electron beam onto a resist applied to a surface of a substrate. And means for generating a drawing control signal for drawing a predetermined test pattern, and means for changing a control amount represented by the drawing control signal over a predetermined period.

A control method of a control device for controlling an electron beam lithography apparatus according to claim 10 is a control device for controlling an electron beam lithography apparatus that performs pattern drawing by irradiating an electron beam onto a resist applied to a surface of a substrate. And a step of generating a drawing control signal for drawing a predetermined test pattern and a step of changing a control amount represented by the drawing control signal over a predetermined period.

An electron beam drawing apparatus according to claim 11 is an electron beam drawing apparatus for drawing a pattern by irradiating an electron beam onto a resist applied to the surface of a substrate, and drawing a predetermined test pattern to be drawn. Means for generating a control signal; means for changing a control amount represented by the drawing control signal over a predetermined period; and irradiating the resist with an electron beam in accordance with the drawing control signal. And means for performing drawing.

According to a twelfth aspect of the present invention, there is provided a program for a control device for controlling an electron beam lithography apparatus, which is responsible for rendering control of an electron beam lithography apparatus that performs pattern rendering by irradiating an electron beam onto a resist applied to a surface of a substrate. A computer-readable program executed by a control device that generates a control signal, wherein the electron beam drawing device performs a process for controlling the electron beam drawing device to draw a predetermined test pattern, and is drawn by the electron beam drawing device. Further, based on the test pattern drawing image representing the test pattern, a process of generating correction data representing a correction amount for the drawing control signal, and the drawing control signal is corrected based on the correction amount represented by the correction data. Process.

The adjustment is performed so that the drawing can be performed with the drawing accuracy or drawing ability inherent in the electron beam drawing apparatus.

It is a figure which shows the whole structure of an electron beam drawing apparatus. It is a block diagram which shows typically the structure of the formatter 50 shown in FIG. 4 is a diagram illustrating a drawing sequence performed by the main body unit 10 under the control of the formatter 50. FIG. It is a figure which shows the drawing control of the concentric circle line by the formatter. It is a figure explaining the deflection drive of the electron beam with respect to the translational movement of the board | substrate 15. FIG. FIG. 5 is a top view of a substrate 15 and is a diagram for explaining deflection control of a formatter that draws lines LN1 to LN4 using a spiral beam locus (broken line) as a concentric beam locus (solid line). It is a figure which shows an example of area distribution of the test pattern drawn on the resist surface. 3 is a diagram illustrating a drawing sequence of a test pattern of the main body unit 10 by a formatter 50. FIG. It is a figure which shows an example of the drawing form of the connection part of each line on radius line SP in the test pattern shown in FIG. It is a figure which shows the modulation signal F1 which the formatter 50 sends out to the main-body part 10 during the trace period of the reference | standard area | region RA shown by FIG. It is a figure which shows the drawing form in the reference | standard area | region RA shown by FIG. It is a figure which shows the modulation signal F1 and the focus adjustment signal FC which the formatter 50 sends out to the main-body part 10 during the trace period of the pit area | region PA1 shown by FIG. It is a figure which shows the focus test pattern drawn in pit area | region PA1 shown by FIG. It is a figure which shows the modulation signal F1 which the formatter 50 sends out to the main-body part 10 during the trace period of pit area | region PA2 shown by FIG. It is a figure which shows an example of the resolution test pattern drawn in pit area | region PA2 shown by FIG. FIG. 8 is a diagram showing another example of a modulation signal F1 sent from the formatter 50 to the main body 10 during the trace period of the pit area PA2 shown in FIG. It is a figure which shows another example of the resolution test pattern drawn in pit area | region PA2 shown by FIG. FIG. 8 is a diagram showing a deflection signal F3 employed when drawing the fifth line LN5 to the eighth line LN8 shown in FIG. FIG. 8 is a diagram showing the magnitude relationship of line widths of each of a fifth line LN5 to an eighth line LN8 shown in FIG. It is a figure which shows the modification of the electron beam drawing apparatus shown by FIG.

Explanation of symbols

10 Main unit 50 Formatter 100 Correction data generation unit

A predetermined test pattern is drawn in the electron beam drawing apparatus to be adjusted, and correction data for correcting the control amount of the drawing control unit in the electron beam drawing apparatus is generated based on an image representing the drawn test pattern. Based on this correction data, the control amount of the drawing control unit in the electron beam drawing apparatus is corrected.

FIG. 1 is a diagram showing an overall configuration of an electron beam lithography apparatus that is adjusted in accordance with the method of adjusting an electron beam lithography apparatus according to the present invention.

As shown in FIG. 1, the electron beam drawing apparatus includes a vacuum chamber 11 including a stage driving device that rotates and translates a substrate 15 for a disk master, an electron beam column 20, and the stage driving device and the electron beam column 20. A block 10 including a drive system for driving (hereinafter, referred to as a main body unit 10), a formatter 50 as a control device of an electron beam drawing apparatus that controls the main body unit 10, and a correction data generation unit 100.

The main unit 10 is an apparatus that creates, for example, a master disk for manufacturing a magnetic disk by an electron beam.

The substrate 15 for the master disc is placed on the turntable 16. For example, a resist material that is exposed to an electron beam is applied to a substrate 15 on a glass substrate, a carbon substrate, or a silicon substrate. The turntable 16 is rotationally driven with respect to the vertical axis (Z axis) of the main surface of the disk substrate by a spindle motor 17 which is a rotational drive device that rotationally drives the substrate 15. The spindle motor 17 is provided on a translation stage (hereinafter also simply referred to as a stage) 18. The stage 18 is coupled to a translation motor 19 which is a transfer (translation drive) 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 substrate 15. Yes.

The substrate 15 is held by suction on the turntable 16. The turntable 16 is made of a dielectric, for example, ceramic, and has an electrostatic chucking mechanism (not shown). Such an electrostatic chucking mechanism includes a turntable 16 and an electrode made of a conductor provided in the turntable 16 for causing electrostatic polarization. A high voltage power source (not shown) is connected to the electrode, and the substrate 15 is held by suction by applying a voltage from the high voltage power source to the electrode.

On the stage 18, optical elements such as a reflection mirror 35A and an interferometer, which are a part of a laser position measurement system 35 described later, are arranged.

The vacuum chamber 11 is installed via an anti-vibration table (not shown) such as an air damper, and vibration transmission from the outside is suppressed. The vacuum chamber 11 is connected to a vacuum pump (not shown), and the interior of the vacuum chamber 11 is set to a vacuum atmosphere at a predetermined pressure by evacuating the chamber.

In the electron beam column 20, an electron gun (emitter) 21 for emitting an electron beam, a converging lens 22, a blanking electrode 23, an aperture 24, a beam deflection coil 25, an alignment coil 26, a deflection electrode 27, a focus lens 28, an objective The lenses 29 are arranged in this order.

The electron gun 21 emits an electron beam (EB) accelerated to several tens to 100 KeV by a cathode (not shown) to which a high voltage supplied from an acceleration high voltage power source (not shown) is applied. The converging lens 22 converges the emitted electron beam. The blanking electrode 23 performs on / off switching (ON / OFF) of the electron beam based on the modulation signal from the blanking drive unit 31. That is, by applying a voltage between the blanking electrodes 23 to greatly deflect the passing electron beam, the electron beam is prevented from passing through the aperture 24, and irradiation of the electron beam to the substrate 15 is turned off (non- Irradiation).

The alignment coil 26 corrects the position of the electron beam based on the correction signal from the beam position corrector 32. The deflection electrode 27 deflects the electron beam in the radial direction and the tangential direction based on a control signal from the deflection driving unit 33. Further, the deflection electrode 27 may be composed of a plurality of deflection electrodes for controlling the deflection in the radial direction and the tangential direction. By such deflection driving, the position of the electron beam spot formed on the surface of the resist coated on the substrate 15 is adjusted.

The focus lens 28 performs focus adjustment on the electron beam based on a focus drive signal (described later) supplied from the focus drive unit 34, and guides the electron beam subjected to the focus adjustment processing to the objective lens 29.

The objective lens 29 converges the electron beam supplied from the focus lens 28 and irradiates it on the surface of the resist. At this time, a latent image is formed at a position irradiated with the electron beam on the resist surface. Hereinafter, the formation of a latent image on the resist surface by such electron beam irradiation is referred to as “drawing”.

The vacuum chamber 11 is provided with a light source 36A and a light detector 36B for detecting the height of the main surface of the substrate 15. The photodetector 36B includes, for example, a position sensor, a CCD (Charge Coupled Device), etc., receives a light beam (laser light) emitted from the light source 36A and reflected by the surface of the substrate 15, and increases the received light signal. This is supplied to the thickness detector 36. The height detection unit 36 detects the height of the main surface of the substrate 15 based on the light reception signal, and supplies a height detection signal indicating the height to the focus driving unit 34.

The focus drive unit 34 generates a focus drive signal corresponding to the focus adjustment amount in the focus lens 28 according to the height detection signal or the focus adjustment signal FC (described later) and supplies the focus drive signal to the focus lens 28.

The laser position measurement system 35 measures the distance to the stage 18 with measurement laser light from a built-in light source (not shown), and supplies the measurement data, that is, position data of the stage 18 to the translation controller 37.

The translation controller 37 performs translation control of the X stage in synchronization with a translation clock signal (T-CLK) F4 which is a reference signal supplied from the formatter 50. The translation controller 37 generates a translation error signal based on the stage position data from the laser position measurement system 35 and sends it to the beam position corrector 32. As described above, the beam position corrector 32 corrects the position of the electron beam based on the translation error signal. The translation controller 37 generates a control signal for controlling the translation motor 19 and supplies it to the translation motor 19.

The rotation controller 38 controls the rotation of the spindle motor 17 in synchronization with a rotation clock signal (R-CLK) F5 which is a reference signal supplied from the formatter 50. More specifically, the spindle motor 17 is provided with a rotary encoder (not shown), and generates a rotation signal when the turntable 16 (that is, the substrate 15) is rotated by the spindle motor 17. The rotation signal includes an origin signal indicating the reference rotation position of the substrate 15 and a pulse signal (rotary encoder signal) for each predetermined rotation angle from the reference rotation position. The rotation signal is supplied to the rotation controller 38. The rotation controller 38 detects a rotation error of the turntable 16 based on the rotary encoder signal, and corrects the rotation of the spindle motor 17 based on the detected rotation error.

Various drawing control signals are supplied from the formatter 50 to the EBR interface circuit (EBR I / F) 39. More specifically, the focus adjustment signal FC, the modulation signal F1, and the deflection signal F3 are supplied from the formatter 50. The blanking drive unit 31 turns on / off the electron beam based on the modulation signal F1, and the deflection drive unit 33 deflects the irradiation direction of the electron beam based on the deflection signal F3. In response to the focus adjustment signal FC, the focus drive unit 34 generates a focus drive signal corresponding to the focus adjustment amount in the focus lens 28 and supplies the focus drive signal to the focus lens 28.

Here, various drawing control signals supplied from the formatter 50 and operations of the formatter 50 based on the control signals will be described in detail below.

FIG. 2 is a diagram showing an internal configuration of the formatter 50 as an EBR control device that controls the main body 10.

As shown in FIG. 2, the formatter 50 includes an EBR control signal generator (processor) 51, a clock signal generator 52, a memory 53, a formatter interface circuit (formatter I / F) 54, an input / output unit 55, and a display unit 56. Consists of.

The clock signal generator 52 is, for example, a clock signal corresponding to CLV (Constant Line Velocity) drawing or CAV (Constant Angular Velocity) drawing, or a rotation clock representing the driving amount of the spindle motor 17 and the translation motor 19 as described later. And generating a translation clock signal.

The memory 53 stores setting values and data related to various control signals described later. The memory 53 stores in advance a program for performing various types of drawing including test drawing (described later).

The input / output unit 55 accepts input of various operation commands from the user or various setting values used when controlling the main body unit 10, and outputs a signal representing the contents (operation command, setting value) as an EBR control signal. Supply to the generator 51. The display unit 56 displays the operation conditions, operation states, set values, and the like of the main body unit 10 and the formatter 50 according to a display command from the EBR control signal generator 51.

The EBR control signal generator 51 reads a program corresponding to an operation command from the input / output unit 55 from the memory 53, generates the following various control signals for controlling the main body unit 10 according to the program, This is supplied to the main body 10 via the interface circuit 54. During this time, the EBR control signal generator 51 receives the following start signal F6 supplied from the main body 10 via the formatter interface circuit 54.

・ Modulation signal F1 (F1-Modulation (/ Blanking)): A signal output by the formatter to turn on / off the electron beam. For example, when “Low”, the electron beam is blanked and the electron beam is turned off.

・ Sawtooth wave deflection signal F3 (F3-Saw-Tooth-Deflection-X), deflection signal F3: deflection signal for concentric spirals. A signal with polarity inversion of the ramp wave depending on the moving direction of the X stage.

· Translation clock signal F4 (F4-Translation-clock): Reference signal to the X stage output by the formatter. The EBR apparatus drives the translation stage (X stage) in synchronization with this signal. The pulse reference unit (ΔX) can be set on the formatter side.

Rotation clock signal F5 (F5-Rotation-clock): Reference signal to the rotating spindle output by the formatter.

-Start signal F6 (F6- / Start): After the end signal F7 (below) is in the "High" state and the translation clock signal F4 and the rotation clock signal F5 become valid, the EBR device side synchronizes with these clocks. When the drawing start radius is reached, the drawing start signal F6 in the “Low” state is supplied to the formatter. As a result, the formatter starts drawing (signal output).

End signal F7 (F7-End): The formatter notifies the end of drawing (signal output) to the EBR device in the “High” state. The end signal F7 is maintained in the “Low” state during the period in which the translation clock signal F4 and the rotation clock signal F5 are valid. Upon receipt of this signal, the EBR apparatus switches the drawing start signal F6 to “High” and ends the current drawing operation.

・ Beam outer periphery direction offset signal F8 (F8-BeamOffsetOut), outer periphery direction offset signal F8, high speed offset (+) signal F8: Signals for offsetting the beam to the outer periphery at high speed.

・ Beam inner circumferential offset signal F9 (F9-BeamOffsetOut), inner circumferential offset signal F9, high-speed offset (−) signal F9: signals for offsetting the beam to the inner circumference at high speed.

Beam-tangential deflection signal F16 (F16-BeamTangentialDeflection), tangential deflection signal F16: Signals that deflect the beam in the tangential direction or circumferential direction (+ θ, -θ direction) at high speed.

Next, regarding the drawing operation by the main body 10 and the formatter 50 having the above-described configuration, a concentric line drawing operation for drawing a plurality of concentric lines on the test substrate 15 coated with a resist will be described with reference to FIGS. This will be described with reference to FIG.

[Concentric line drawing operation]
After the substrate 15 is set in the EBR main body 10, when the user performs a concentric line drawing command operation for drawing a concentric line by the input / output unit 55, the formatter 50 draws the concentric line drawing stored in the memory 53. The following control according to the program is sequentially executed.

First, as shown in FIG. 3, the formatter 50 starts sending the translation clock signal F4 and the rotation clock signal F5 to the main body 10 and sends an end signal F7 (F7-End) to be sent to the main body 10 ". Switching from the “High” state to the “Low” state (FIG. 3, time point Tp). The translation clock signal F4 and the rotation clock signal F5 at this time are clock signals having a frequency (Fini) at the start of drawing. When the supply of the translation clock signal F4 and the rotation clock signal F5 is started, the main body 10 operates in synchronization with these clocks, and then the main body 10 becomes “Low” (when the drawing start radius is reached). An active) drawing start signal F6 (F6- / Start) is sent to the formatter 50.

In response to the “Low” (active) start signal F 6, the formatter 50 starts sending the modulation signal F 1 and the deflection signal F 3, which are drawing signals, to the main body 10 as shown in FIG. 3 or FIG. . As shown in FIG. 3 or FIG. 4, the deflection signal F3 is a sawtooth signal (analog voltage signal), and the reference voltage (V = Vref = T1) during one rotation of the substrate 15 (Tini to T1). The level changes linearly from 0 volt) to V = VD. At time T1, the deflection signal F3 is returned to the reference voltage Vref (= 0 volt), and the electron beam is returned to the reference deflection position (for example, a position perpendicular to the substrate 15). As a result, the substrate 15 translates at a constant speed based on the translation clock (T-CLK) F4 as shown in FIG. More specifically, the substrate 15 extends in the X direction from the position at the start of drawing (indicated by a broken line, the center of the substrate is indicated by O) to the position at the end of one rotation (indicated by a solid line, the center of the substrate is indicated by O ′) Translate. At this time, as shown in FIG. 5, the electron beam EB is deflected so as to follow the substrate 15 by the deflection signal F3. That is, as shown in FIG. 6, when the deflection (that is, the emission direction) of the electron beam EB is fixed, a spiral beam locus (indicated by a broken line) is formed on the substrate 15, but the deflection signal F3. Thus, the main body 10 draws a concentric line LN1 (shown by a solid line). In the following description, a concentric line having a line number j (ie, LN = j) is described as LNj. Simultaneously with the end of drawing of the second line LN1 (T = T1), the deflection voltage is returned to the reference voltage (V = Vref = 0 volt, FIG. 4) by the deflection signal F3. That is, the electron beam is returned to the deflection position (reference deflection position) at the start of drawing of the line LN1, and the beam spot of the electron beam EB is at the same angular position as the angular position at the end of drawing of the line LN1 with respect to the center of the substrate 15. Returned. On the other hand, at this time, the radial position (radial position) of the beam spot on the substrate 15 with respect to the center of the substrate 15 has moved by the translational distance required for drawing the line LN1. At this time, this distance becomes a pitch q (referred to as a line pitch) between lines as shown in FIG.

Then, in the second to fourth rotations (REV = 2 to 4) of the substrate 15, the formatter 50 repeatedly executes the same control as described above, thereby the first concentric circles separated from each other by the line pitch q. Drawing of the line LN1 to the fourth line LN4 is performed (FIG. 6). In FIG. 6, the line pitch is enlarged for the sake of explanation.

Here, in order to accurately draw a concentric line having a desired line width on the resist surface, it is necessary to perform various adjustments of the main body 10 itself when the main body 10 is installed or periodically.

Needless to say, it is better to place the substrate 15 with high precision so that the center of the substrate 15 coincides with the rotation center of the rotary stage 16.

Therefore, the following test pattern drawing is performed in order to grasp the adjustment location and the adjustment amount that need to be performed among all adjustment locations (not described) in the main body 10.

[Test pattern drawing operation]
First, the undrawn substrate 15 coated with a resist is set on the rotary stage 16 of the EBR main body 10. When the user performs a test drawing command operation for drawing a test pattern using the input / output unit 55, the formatter 50 executes various drawing controls on the main body unit 10 in accordance with a test drawing program stored in the memory 53.

In the following, the test pattern is drawn as an example in which eight concentric lines (LN1 to LN8) are drawn in the sector-like groove areas GA1 to GA3 on the resist surface as shown in FIG. The operation will be described.

[Groove areas GA1 to GA3: seam error pattern by LN1 to LN4]
First, as shown in FIG. 8, the formatter 50 switches the end signal F7 sent to the main body 10 from the “High” state to the “Low” state, and starts sending the translation clock signal F4 and the rotation clock signal F5. (FIG. 8, time point Tp). When the supply of the translation clock signal F4 and the rotation clock signal F5 is started, the main body 10 operates in synchronization with these clocks, and then the main body 10 becomes “Low” (when the drawing start radius is reached). An active) drawing start signal F6 (F6- / Start) is sent to the formatter 50.

The formatter 50 starts sending the modulation signal F1 and the deflection signal F3, which are drawing signals, to the main body 10 as shown in FIG. 8 in response to the “Low” (active) start signal F6. At this time, the deflection signal F3 is a signal in which the level change occurs in a sawtooth shape as shown in FIG. That is, the level of the deflection signal F3 rises linearly from the reference voltage Vref (eg, 0 volts) to the positive peak potential during one rotation of the substrate 15 (eg, between Tini and T1). 15 returns to the reference voltage Vref at the timing of exactly one rotation. As a result, the substrate 15 translates at a constant speed based on the translation clock F4. More specifically, as shown in FIG. 7, the substrate 15 is in the X direction from the position on the radial line SP corresponding to the drawing start position for each concentric circle line (indicated by the alternate long and short dash line) until it rotates once. Translate to At this time, as shown in FIG. 5, the electron beam EB is deflected so as to follow the substrate 15 by the deflection signal F3.

By the series of controls as described above, the main body 10 starts irradiating the resist surface of the substrate 15 with the electron beam EB from time Tini as shown in FIG. That is, the operation for drawing each of a plurality of concentric lines is started from the position (position on the radial line SP shown in FIG. 7) where the electron beam EB is first irradiated at the time point Tini. For example, when the substrate 15 rotates once from the time point Tini and the electron beam EB reaches the position on the radius line SP again, the first line LN1 as shown in FIG. 7 is drawn. At this time, a concentric first line LN1 is formed on the radial line SP. Simultaneously with the drawing of the first line LN1, the deflection voltage is returned to the reference voltage Vref (0 volts) by the deflection signal F3. That is, the electron beam is returned to the deflection position (reference deflection position) at the start of drawing of the first line LN1, and the beam spot of the electron beam EB is the angular position at the end of drawing of the first line LN1 with respect to the center of the substrate 15. Is returned to the same angular position, that is, on the radial line SP of FIG. On the other hand, at this time, the radial position (radial position) of the beam spot on the substrate 15 with respect to the center of the substrate 15 has moved by the translational distance required for drawing the first line LN1. At this time, the distance becomes a line pitch q between lines as shown in FIG.

Then, during the second to fourth rotations (T2 to T4) of the substrate 15, the formatter 50 repeatedly executes the same control as described above, whereby concentric second lines LN2 separated from each other by the line pitch q. The fourth line LN4 is drawn. At this time, concentric first to fourth lines LN2 to LN4 are formed on the radial line SP.

By the way, the peak potentials of the sawtooth pulses in the deflection signal F3 supplied from the formatter 50 to the main body 10 to draw the first lines LN1 to LN4 are different from each other.

That is, as shown in FIG.
The peak potential of the sawtooth pulse KP1 during the drawing period (Tini to T1) of the first line LN1,
The peak potential of the sawtooth pulse KP2 in the drawing period (T1 to T2) of the second line LN2,
The peak potential of the sawtooth pulse KP3 in the drawing period (T2 to T3) of the third line LN3,
The peak potential of the sawtooth pulse KP4 in the drawing period (T3 to T4) of the fourth line LN4,
Are different.

That is, the slope of the level transition with time of the sawtooth pulse KP in the deflection signal F3 differs for each line. As a result, for example, as shown in FIG. 9, the first line LN1 to the fourth line LN4, each having a different amount of misalignment at the drawing start position (radius line SP), are drawn. At this time, the line pitch between adjacent ones of the first line LN1 to the fourth line LN4 is also different.

On the other hand, in each of the reference position area RA and the pit areas PA1 to PA3 shown in FIG. 7, the formatter 50 performs control to cause the main body 10 to perform drawing of various reference patterns as follows.

[Reference position area RA: Reference position recording]
First, during the electron beam tracing period in the reference position region RA shown in FIG. 7, the formatter 50 supplies the main body 10 with a modulation signal F1 having a waveform as shown in FIG. 10.

That is, as shown in FIG. 10, the formatter 50 maintains the “Low” state only during the predetermined pulse width W2 (W2 <W1), the pulse P1 maintaining the “Low” state only during the predetermined pulse width W1. A modulated signal F1 having a pulse sequence of a pulse P4 that maintains the “Low” state only during the pulses P2 and P3 and the pulse width W1 is supplied to the main body 10. At this time, the pulses P1 and P4 both having the pulse width W1 are separated from each other by a predetermined interval T1, and within this interval T1, the pulses P2 and P3 are separated from each other by a predetermined interval T2 (T2 <T1). ing.

According to the modulation signal F1 as shown in FIG. 10, the irradiation of the electron beam is interrupted only while the modulation signal F1 is in the “Low” state by the pulses P1 to P4.

Therefore, in the reference position region RA, as shown in FIG. 11, the pulse width W1 is set at two positions separated from each other by the gap interval GK1 corresponding to the interval T1 for each line (LN1 to LN4). A first gap section g1 in which line drawing is interrupted over the corresponding length θ1 is formed. Further, in the gap interval GK1, the second gap section g2 in which the line drawing is interrupted at the two positions separated from each other by the gap interval GK2 corresponding to the interval T2 over the length θ2 corresponding to the pulse width W2. Are formed respectively. At this time, the first gap section g1 is drawn with a section width such that the developed substrate 15 can be discriminated with the naked eye or an optical microscope. This is for quickly specifying a region where an image is taken with an electron microscope when analyzing a drawing test pattern to be described later. A cap having such a section width can be similarly applied to various test areas described below.

[Pit area PA1: Focus test pattern drawing]
Next, during the electron beam tracing period in the pit areas PA1 to PA3 shown in FIG. 7, the formatter 50 receives the modulation signal F1 and the focus adjustment signal FC having the waveforms shown in FIG. Supplied to the unit 10.

That is, as shown in FIG. 12, the formatter 50 supplies the main body 10 with a modulation signal F1 in which pulses P1 to P11 each maintaining a “High” state for a predetermined pulse width Wa are continuous. Further, during this time, the formatter 50 adjusts the focus adjustment amount to K5, K4, K3, K2, K1, K0, -K1, -K2, -K, corresponding to the timing of each of the pulses P1 to P11 as shown in FIG. A focus adjustment signal FC to be lowered step by step by different amounts, such as K3, -K4, and -K5, is supplied to the main body unit 10.

According to the modulation signal F1 as shown in FIG. 12, the electron beam is irradiated on the resist surface only while the modulation signal F1 is in the “High” state by the pulses P1 to P11. Further, during this time, the focus adjustment amount for the electron beam changes in 11 steps such as K5, K4, K3, K2, K1, K0, -K1, -K2, -K3, -K4, -K5 by the focus adjustment signal FC. Go.

Therefore, in the pit area PA1, the focus adjustment amount is changed along the concentric circle line for each line (LN1 to LN4) as shown in FIG. 13 by the electron beams irradiated in different states. A focus test pattern composed of ₁₁ latent image marks QP ₁ to QP ₁₁ corresponding to each of −K5 to K5 is drawn. At this time, each of the latent image marks QP ₁ to QP ₁₁ in the focus test pattern has a smaller outer shape (area) as it is drawn with a smaller focus error. For example, in the example of FIG. 13, the latent image mark QP ₇ has the smallest outer shape (area) among the latent image marks QP ₁ to QP ₁₁ .

[Pit area PA2: Resolution test pattern drawing]
Further, during the electron beam tracing period in the pit areas PA1 to PA3 shown in FIG. 7, the formatter 50 supplies the main body 10 with a modulation signal F1 having a waveform as shown in FIG.

That is, as shown in FIG. 14, the formatter 50 repeats the transition from the “Low” state to the High ”state and the“ Low ”state in a predetermined constant cycle WR, and the pulse width in the High state. Is supplied to the main body 10 with a modulation signal F1 composed of pulses P1 to P10 that gradually decrease to W11 to W20 as time elapses.

According to the modulation signal F1 as shown in FIG. 14, the resist surface is irradiated with the electron beam only while the modulation signal F1 is in the “High” state by the pulses P1 to P10.

Therefore, if the main body 10 has the drawing accuracy that should be inherent, as shown in FIG. 15, each of the pulse widths W11 to L11 in FIG. 14 is arranged along the concentric lines (LN1 to LN4) in the pit area PA2. A resolution test pattern composed of ten latent image marks having mark lengths PW11 to PW20 corresponding to each of W20 is drawn. Further, the intervals between the central portions of the latent image marks adjacent to each other on one line are all the interval Wc. That is, when the main body 10 does not have the drawing accuracy that should be originally provided, the mark length of each drawn latent image mark does not coincide with each of the mark lengths PW11 to PW20, or the latent images adjacent to each other. The interval between the center portions of the marks does not coincide with the interval Wc.

In the pit area PA2, the formatter 50 may supply the main body 10 with a modulation signal F1 having a waveform as shown in FIG. 16 instead of FIG.

That is, as shown in FIG. 16, the formatter 50 has the same pulse width W20 for maintaining the “High” state, and the interval between the centers of the adjacent pulses gradually decreases. Then, a modulation signal F1 composed of continuous pulses P1 to P10 is supplied to the main body 10.

According to the modulation signal F1 as shown in FIG. 16, in the pit area PA2, as shown in FIG. 17, for each line (LN1 to LN4), the interval between adjacent ones is gradually increased. A resolution test pattern composed of ten changing latent image marks is drawn.

[Groove areas GA1 to GA3: Overlay test pattern with LN5 to LN8]
Next, the formatter 50 sends a deflection signal F3 as shown in FIG. 18 to the main body 10 instead of the deflection signal F3 shown in FIG. 8, thereby bringing the fourth line LN4 on the resist surface to the inner circumference side. As shown in FIG. 7, the fifth line LN5 to the eighth line LN8 are sequentially drawn.

That is, first, while the substrate 15 is rotated once (between T4 and T5), the level rises from the reference voltage Vref (for example, 0 volt) to the peak potential VP1 of the positive polarity, and at the timing of just one rotation. The substrate 15 itself translates in response to the sawtooth pulse KP5 (deflection signal F3) having a waveform returning to the reference voltage Vref. During this time, the electron beam EB is deflected so as to follow the substrate 15 that translates in accordance with the transition of the potential level caused by the sawtooth pulse KP5. By such an operation, the main body 10 causes the rotation of the substrate 15 during one rotation from the position (position on the radius line SP shown in FIG. 7) irradiated with the electron beam EB at the time T4 as shown in FIG. A fifth line LN5 for one rotation is drawn as shown in FIG. At the same time as the drawing of the fifth line LN5 is completed, the deflection voltage is returned to the reference voltage Vref by the deflection signal F3. The irradiation position of the electron beam moves toward.

Next, while the substrate 15 rotates twice (between T5 and T7), the level rises from the reference voltage Vref to the positive peak potential VP2 (VP2 = 2 · VP1), and the reference voltage is just at the timing of two rotations. The substrate 15 itself translates in response to the sawtooth pulse KP6 (deflection signal F3) having a waveform returning to Vref. During this time, the electron beam EB is deflected so as to follow the substrate 15 that translates in accordance with the transition of the potential level caused by the sawtooth pulse KP6. By such an operation, the main body 10 causes the concentric circles corresponding to one rotation to be positioned at the inner circumferential side by the line pitch q from the fifth line LN5 during one rotation of the substrate 15 (T5 to T6). 6 line LN6 is drawn. Then, while the substrate 15 further rotates (T6 to T7), the main body 10 irradiates the electron beam for one rotation so as to trace on the sixth line LN6. That is, the overwriting is performed twice for the sixth line LN6. Simultaneously with the end of the operation, the deflection voltage based on the deflection signal F3 is returned to the reference voltage Vref, and is directed toward the inner periphery of the disc by half the translation distance required for drawing the sixth line LN6, that is, the line pitch q. The electron beam irradiation position moves.

Next, the level rises from the reference voltage Vref to the positive polarity peak potential VP3 (VP3 = 3 · VP1) while the substrate 15 is rotated three times (between T7 and T10). The substrate 15 itself translates in response to the sawtooth pulse KP7 (deflection signal F3) having a waveform returning to Vref. During this time, the electron beam EB is deflected so as to follow the substrate 15 that translates in accordance with the transition of the potential level caused by the sawtooth pulse KP7. By such an operation, the main body 10 causes the concentric circles corresponding to one rotation to be positioned at the inner circumferential side by the line pitch q from the sixth line LN6 during one rotation of the substrate 15 (T7 to T8). 7 lines LN7 are drawn. Next, while the substrate 15 is further rotated once (T8 to T9), the main body unit 10 irradiates the electron beam for one rotation so as to trace on the seventh line LN7. That is, overwriting is performed twice for the seventh line LN7. Then, while the substrate 15 further rotates (T9 to T10), the main body 10 irradiates the electron beam for one rotation so as to trace on the seventh line LN7. That is, the third line LN7 is overwritten three times. Simultaneously with the end of this operation, the deflection voltage based on the deflection signal F3 is returned to the reference voltage Vref, and is 1/3 of the translational distance required for drawing the seventh line LN7, that is, the line pitch q toward the inner periphery of the disk. The irradiation position of the electron beam moves toward.

Next, while the substrate 15 is rotated four times (between T10 and T14), the level increases from the reference voltage Vref to the positive polarity peak potential VP4 (VP4 = 4 · VP1), and the reference voltage is just at the timing of four rotations. The substrate 15 itself translates in response to the sawtooth pulse KP8 (deflection signal F3) having a waveform returning to Vref. During this time, the electron beam EB is deflected so as to follow the substrate 15 that translates in accordance with the transition of the potential level caused by the sawtooth pulse KP8. By such an operation, the main body 10 causes the concentric circles corresponding to one rotation to be positioned at the inner circumferential side by the line pitch q from the seventh line LN7 during one rotation of the substrate 15 (T10 to T11). 8-line LN8 is drawn. Next, while the substrate 15 is further rotated once (T11 to T12), the main body 10 irradiates the electron beam for one rotation so as to trace on the eighth line LN8. That is, overwriting is performed twice on the eighth line LN8. Then, while the substrate 15 further makes one rotation (T12 to T13), the main body unit 10 irradiates the electron beam for one rotation so as to trace on the eighth line LN8. That is, three times overwriting is performed on the eighth line LN8. Then, while the substrate 15 further rotates (T13 to T14), the main body 10 irradiates the electron beam for one rotation so as to trace on the eighth line LN8. That is, the fourth line LN8 is overwritten four times.

Thus, according to the modulation signal F1 as shown in FIG.
The fifth line LN5 written once by the electron beam irradiation for one turn,
A sixth line LN6 overwritten twice by electron beam irradiation for two rounds,
Seventh line LN7 overwritten three times by electron beam irradiation for three rounds,
An eighth line LN8 overwritten four times by electron beam irradiation for four laps,
The overwriting pattern will be drawn.

At this time, as shown in FIG. 19, each of the fifth line LN5 to the eighth line LN8 becomes thicker as the number of overwriting increases.

When the drawing of the test pattern on the resist surface as shown in FIG. 7 is completed by the above operation, the resist surface is developed and the following test pattern analysis process is performed.

[Drawing test pattern analysis]
First, the following portions (A) to (D) are respectively photographed from the resist surface subjected to the development processing as described above by using a scanning electron microscope (SEM). Test pattern image data representing the photographed image is supplied to the correction data generation unit 100 shown in FIG.

(A) Joint portion of each of the first line LN1 to the fourth line LN4 on the radius line SP as the drawing start position shown in FIG. 7 (FIG. 9)
(B) Focus test pattern in the pit area PA1 shown in FIG. 7 (FIG. 13)
(C) Resolution test pattern in the pit area PA2 shown in FIG. 7 (FIG. 15 or FIG. 17)
(D) A part of each of the fifth line LN5 to the eighth line LN8 shown in FIG. 7 (FIG. 19)
In performing the imaging operations (A) to (D) described above, first, from the resist surface shown in FIG. 7, the location where each line is cut in the form as shown in FIG. 11, that is, the reference position region RA is searched. Then, the photographic targets as in the above (A) to (D) are detected on the basis of the position. This detection can be performed with the naked eye or an optical microscope.

The correction data generation unit 100 performs various kinds of drawing control signals generated by the formatter 50 by performing the following image processing on the test pattern image data, that is, the modulation signal F1, the deflection signal F3, and the focus adjustment signal. Correction data DOF for correcting the control amount for FC is generated and supplied to the formatter 50.

For example, the correction data generation unit 100, as shown in FIG. 9, based on the test pattern image data representing the joint portions of the first line LN1 to the fourth line LN4, each of the first line LN1 to the fourth line LN4. The one with the smallest amount of deviation at the joint (radius line SP) is selected from the inside. Here, the correction data generation unit 100 includes a memory (not shown) in which deflection correction values corresponding to the first line LN1 to the fourth line LN4 are stored in advance.

For example, each of the first line LN1 to the fourth line LN4 includes
1st line LN1: “1”,
Second line LN2: “0”,
Third line LN3: “−1”,
Fourth line LN3: “−2”,
A deflection correction value is assigned.

The correction data generation unit 100 reads out the deflection correction value corresponding to the line having the smallest deviation amount at the joint as described above from the memory. That is, when line drawing for one round is performed, a deflection correction value for correcting a shift at the joint portion (radius line SP) and maintaining a predetermined line pitch q is read from the memory. . In the example shown in FIG. 9, since the amount of deviation at the joint portion is the smallest in the second line LN2, the deflection correction value “0” corresponding to the second line LN2, ie, there is no deflection correction. A deflection correction value is obtained.

Further, as shown in FIG. 13, the correction data generation unit 100 is the most among the latent image marks QP ₁ to QP ₁₁ arranged along one line based on the test pattern image data representing the focus test pattern. A latent image mark QP having a small outer shape (area) is selected, and a focus adjustment amount K corresponding to the latent image mark QP is obtained as a focus correction value. In this case, in the example shown in FIG. 13, since the latent image mark QP ₇ most outer shape (area) is small, the focus adjustment amount -K1 corresponding to the latent image mark QP ₇ is a focus correction value. That is, the focus at the time of drawing the test pattern may be set to K1, and a value obtained by subtracting the focus value of K1 from the focus value at the time of drawing becomes the focus adjustment value.

Further, as shown in FIG. 15, the correction data generation unit 100 is adjacent to the mark length of each of the 10 latent image marks arranged along one line based on the test pattern image data representing the resolution test pattern. The distance between the center portions of the latent image marks is obtained. Then, the correction data generation unit 100 calculates the difference between the predetermined interval Wc and the interval between the center portions of the latent image marks, the mark length of each of the 10 latent image marks, and the predetermined mark lengths PW11 to PW20. A difference is obtained, and a resolution improvement correction value corresponding to both differences is obtained. That is, when the adjustment is in the optimum state, the main body 10 has a mark length of each of the 10 latent image marks drawn as shown in FIG. All the intervals between the center portions of the image marks have a resolution that matches the predetermined interval Wc. However, if the adjustment of the main body 10 is not optimal, the mark length and interval of each latent image mark as described above will deviate from predetermined values (PW11 to PW20, Wc), and a desired resolution can be obtained. No state. Therefore, the amount of deviation is used as a correction value for improving the resolution.

Further, as shown in FIG. 19, the correction data generation unit 100 has a line width of each of the fifth line LN5 to the eighth line LN8 based on test pattern image data representing a part of each of the fifth line LN5 to the eighth line LN8. Measure. At this time, as the number of times of overwriting increases, the distortion of the lines is averaged to become an appropriate line, but the line width itself increases with an increase in the number of overwriting. Therefore, the correction data generation unit 100 selects a line width that is narrower than the predetermined reference width among the line widths of the fifth line LN5 to the eighth line LN8, and the number of overwriting times corresponding to the line. Is obtained as the optimum overwriting number. Note that the drawing pattern shown in FIG. 19 is a line having a predetermined line width, that is, a pattern having a predetermined width (size) in the disk radial direction or the rotation direction while changing the interval between adjacent ones in a stepwise manner. If it is drawn, but this predetermined width is larger than the expected size, adjacent patterns will come into contact with each other when the interval is narrow, and individual patterns will be recognized. become unable. The cause may be that the focus is not narrowed down. At this time, the correction data generation unit 100 (or the user) generates a focus correction value for adjusting the focus.

Then, the correction data generation unit 100 supplies the formatter 50 with correction data DOF indicating each of the optimum overwriting number, resolution improvement correction value, focus correction value, and deflection correction value obtained as described above.

The formatter 50 sends, to the main body 10, various processing control signals that are to be drawn by an electron beam, which have been subjected to processing for correcting the control amount by the value indicated by the correction data DOF. To do. For example, the formatter 50 adds (or subtracts) the focus correction value indicated by the correction data DOF to the focus adjustment signal indicating the focus adjustment amount of the electron beam to the main body unit 10 as the final focus adjustment signal FC. Supply. Further, the formatter 50 supplies the main body 10 with a final deflection signal F3 obtained by adding (or subtracting) the deflection correction value indicated by the correction data DOF to the deflection signal indicating the deflection amount of the electron beam.

That is, the formatter 50 draws various drawing control signals (F1, F3, FC) to be sent for drawing control of the main unit 10 to draw test patterns as shown in FIGS. 7, 13, 15, 17, and 19. Adjustment is performed so that the correction value indicated by the correction data DOF obtained based on the result is corrected.

By such adjustment, the main body 10 irradiates the electron beam with a predetermined drawing accuracy (drawing ability) that is supposed to be, that is, an appropriate focus state, and connects a plurality of concentric circle lines at the joints at a predetermined constant line pitch. It becomes possible to draw without causing a shift in the portion.

In the above embodiment, the correction data generation unit 100 shown in FIG. 1 generates the correction data DOF based on the test pattern drawing result (test pattern image data). By the way, according to the test pattern, the position of the drive unit (blanking drive unit 31, deflection drive unit 33, focus drive unit 34) that requires adjustment as an electron beam drawing apparatus and the correction amount thereof are visually monitored. It becomes possible. Therefore, the operation of the correction data generation unit 100 may be artificially performed.

In the above embodiment, the formatter 50 is provided outside the main body 10. However, the formatter 50 may be mounted inside the main body 10 as shown in FIG.

適用 It can be applied to the initial adjustment at the time of installation of the electron beam lithography system or maintenance adjustment.

Claims

An adjustment method of an electron beam drawing apparatus that performs pattern drawing by irradiating an electron beam onto a resist applied to a surface of a substrate,
A test pattern drawing step of drawing a predetermined test pattern in the electron beam drawing apparatus;
Test pattern drawing image acquisition process for obtaining a test pattern drawing image;
A correction data generation process for generating correction data for correcting a control amount of a drawing control unit in the electron beam drawing apparatus based on the test pattern drawing image;
And a correction step of correcting a control amount of the drawing controller in the electron beam drawing apparatus based on the correction data.
The test pattern includes a pattern that can test at least one of the joint between the start point and the end point of each pattern, the focus state of the electron beam, and the drawing resolution when drawing a pattern composed of a plurality of concentric circles. The method of adjusting an electron beam lithography apparatus according to claim 1.
The test pattern drawing step includes a step of deflecting the irradiation direction of the electron beam while rotating the substrate to draw a plurality of concentric lines.
The method for adjusting an electron beam lithography apparatus according to claim 1, further comprising a step of varying a peak of a deflection amount in an irradiation direction of the electron beam for each concentric line.
3. The test pattern drawing process includes a process of stepwise changing a focus adjustment amount of the electron beam within a predetermined first period within one rotation period of the substrate. Method for adjusting an electron beam drawing apparatus.
In the test pattern drawing process, a period for stopping the irradiation of the electron beam is provided for each predetermined period within a predetermined second period within one rotation period of the substrate, and the irradiation of the electron beam within each predetermined period is performed. The method for adjusting an electron beam lithography apparatus according to claim 1, further comprising a step of varying the periods.
The test pattern drawing step includes a step of drawing a plurality of patterns each having a predetermined width in the radial direction of rotation of the substrate while changing the interval between adjacent ones in a stepwise manner. Item 3. The method for adjusting an electron beam lithography apparatus according to Item 1 or 2.
An adjustment method of a control device that generates a drawing control signal responsible for drawing control of an electron beam drawing device that performs pattern drawing by irradiating an electron beam to a resist applied to a surface of a substrate,
A step of performing a control for drawing a predetermined test pattern to the electron beam drawing apparatus;
A step of generating correction data representing a correction amount for the drawing control signal based on a test pattern drawing image representing the test pattern drawn by the electron beam drawing apparatus;
And a step of correcting the drawing control signal based on the correction amount represented by the correction data. A method for adjusting a control device for controlling an electron beam drawing apparatus, comprising:
The test pattern includes a pattern capable of monitoring at least one of a joint of each pattern, a focus state of an electron beam, and a drawing resolution when drawing a pattern composed of a plurality of concentric circles. A method for adjusting a control device for controlling the electron beam lithography apparatus according to claim 7.
A control device for controlling an electron beam drawing apparatus that performs pattern drawing by irradiating an electron beam onto a resist applied to a surface of a substrate,
Means for generating a drawing control signal for drawing a predetermined test pattern;
Means for changing a control amount represented by the drawing control signal over a predetermined period of time.
A control method of a control device for controlling an electron beam drawing apparatus that performs pattern drawing by irradiating an electron beam onto a resist applied to a surface of a substrate,
A step of generating a drawing control signal for drawing a predetermined test pattern;
And a step of changing a control amount represented by the drawing control signal over a predetermined period.
An electron beam drawing apparatus that performs pattern drawing by irradiating an electron beam onto a resist applied to a surface of a substrate,
Means for generating a drawing control signal for drawing a predetermined test pattern;
Means for changing a control amount represented by the drawing control signal over a predetermined period;
Means for irradiating the resist with an electron beam in accordance with the drawing control signal, thereby drawing the test pattern.
A computer-readable program executed by a control device that generates a drawing control signal responsible for drawing control of an electron beam drawing device that performs pattern drawing by irradiating an electron beam onto a resist applied to the surface of a substrate,
A step of performing a control for drawing a predetermined test pattern to the electron beam drawing apparatus;
A step of generating correction data representing a correction amount for the drawing control signal based on a test pattern drawing image representing the test pattern drawn by the electron beam drawing apparatus;
And a process of correcting the drawing control signal based on the correction amount represented by the correction data.