JP7299206B2 - Electron Beam Irradiation Area Adjustment Method and Adjustment System, Electron Beam Irradiation Area Correction Method, and Electron Beam Irradiation Device - Google Patents

Description

The present invention relates to an electron beam irradiation area adjustment method and adjustment system, an electron beam irradiation area correction method, and an electron beam irradiation apparatus.

2. Description of the Related Art An electron beam irradiation apparatus irradiates a mask with an electron beam in, for example, a semiconductor device manufacturing process, thereby improving the etching resistance of the mask.

JP 2016-27604 A

An object of the present invention is to provide an electron beam irradiation apparatus with good performance.

According to one aspect of the present invention, there is provided a method for adjusting an irradiation area of an electron beam in an electron beam irradiation apparatus that irradiates an irradiation target with an electron beam deflected by a deflector, wherein the deflection is performed based on an electron beam irradiation recipe. an electron beam irradiation step of irradiating the electron beam while changing the irradiation position on an adjustment plate that detects the current corresponding to the irradiated electron beam by controlling the device, and acquiring the current detected from the adjustment plate. an image forming step of forming image data corresponding to the obtained current value; and a determining step of determining whether or not the irradiation area of the electron beam is appropriate based on the formed image data. and a recipe update step of updating the electron beam irradiation recipe when the irradiation area is determined to be inappropriate.

The figure which shows typically a schematic structure of an electron beam irradiation apparatus. 4 is a schematic cross-sectional view of the sensor unit 116; FIG. The figure which shows the structural example of the particle catcher 11B. FIG. 4 is a diagram for explaining the role of an aperture 126; FIG. 4 is an explanatory diagram of control for deflecting an electron beam in XY directions; FIG. 4 is an explanatory diagram of control for deflecting an electron beam in XY directions; 1 is a diagram showing a schematic configuration of an irradiation area adjustment system 200 in an electron beam irradiation apparatus; FIG. FIG. 2 is a top view schematically showing an adjustment plate 21; FIG. 4 is a diagram schematically showing an irradiation area of an electron beam with respect to an adjustment plate 21; FIG. 4 is a diagram schematically showing an irradiation area of an electron beam with respect to an adjustment plate 21; 4 is a flowchart showing a procedure for adjusting an irradiation area; FIG. 4 is a diagram showing temporal changes in the voltage applied to the electrode 2115; The figure which shows the relationship of the irradiation area and time in FIG. 2CA. The figure which shows the relationship between an irradiation area and time in FIG. 2CB. FIG. 4 is a diagram showing temporal changes in acquired current values; FIG. 4 is a diagram showing temporal changes in acquired current values; The figure which shows the image data formed corresponding to the electric current value shown in FIG. 2GA. The figure which shows the image data formed corresponding to the electric current value shown in FIG. 2GA. FIG. 10 is a diagram showing the time change of the voltage applied to the electrode 2115 after adjustment. FIG. 4 is a diagram schematically showing irradiation regions 200 and 200' of electron beams. 3B schematically shows voltages Vv(t) and Vh(t) respectively applied to electrodes V and H in a deflector 115 to obtain the illuminated area 200 of FIG. 3A; FIG. FIG. 4 is a diagram schematically showing voltages Vv(t) and Vh(t)+kVv(t) applied to electrodes V and H, respectively, for correcting horizontal distortion of the irradiation area 200'. FIG. 4 is a diagram schematically showing irradiation regions 200 and 200″ of electron beams. FIG. 4 is a diagram schematically showing voltages Vv(t)+kVh(t), Vh(t) applied to electrodes V, H, respectively, in order to correct the vertical distortion of the irradiation region 200″. The figure which shows typically the irradiation area|region 41 of an electron beam. FIG. 4B is a diagram schematically showing voltages Vh(t) and Vv(t) respectively applied to electrodes H and V in a deflector 115 to obtain the irradiation area 41 of FIG. 4A; The figure which shows typically the irradiation area|region 42 of an electron beam. FIG. 4D is a diagram schematically showing voltages Vh(t) and Vv(t) applied to electrodes H and V of a deflector 115 from point 4P1 to point 4P2 in the irradiation region 42 of FIG. 4C, respectively; FIG. 4D is a diagram schematically showing voltages Vh(t) and Vv(t) applied to electrodes H and V of the deflector 115 from point 4P2 to point 4P3 in the irradiation region 42 of FIG. 4C, respectively; 1 is a diagram showing a schematic configuration of an electron beam position detection system 500 according to this embodiment; FIG. It is a top view of the measurement unit 127 which concerns on this embodiment. FIG. 4 is a top view of the measurement unit 127 according to the present embodiment when the plate 52 is removed; FIG. 5C is a schematic cross-sectional view showing the AA cross section in FIG. 5B; 5 is a diagram showing an example of arrangement of through holes in a plate 52; FIG. 5 is a flow chart showing an example of processing for aligning the position of the electron beam with the center of the upper right region of the plate 52. FIG. Schematic which expands and shows the structure which concerns on the application pin of an electron beam irradiation apparatus. Schematic diagram showing wiring of a potential control unit. 4 is a flow chart showing an example of the operation of the electron beam irradiation device; FIG. 2 is a plan view showing a configuration related to teaching of a robot hand; FIG. 6C is a cross-sectional view of the configuration shown in FIG. 6D along line AA; The top view of a teaching plate. Schematic which shows an example of the conventional connection piping. Schematic which shows an example of the connection instrument by this embodiment. 7B is a plan view of the first flange member of the coupling device shown in FIG. 7B; FIG. FIG. 7D is a view showing a cross section of the first flange member shown in FIG. 7C along line AA; 7C is a plan view of the second flange member of the coupling device shown in FIG. 7B; FIG. FIG. 7E is a view showing a cross section of the second flange member shown in FIG. 7E along line BB; The flowchart which shows an example of the method of connecting pipes with different flange sizes using the connection tool shown to FIG. 7B. Sectional drawing of the electron beam generator 112 which concerns on this embodiment. FIG. 3 is a view of the photocathode 82 viewed from below; The figure which looked at the insulating layer 83 from the downward direction. The figure which looked at the electrode array 84 from the downward direction. The figure which looked at the aperture_diaphragm|restriction 86 from the downward direction. Simulation results showing the shape of the emitted electron beam when the voltage applied to each electrode 840 is -1.00V. Simulation results showing the shape of the emitted electron beam when the voltage applied to each electrode 840 is -0.50V. Simulation results showing the shape of the emitted electron beam when the voltage applied to each electrode 840 is -0.13V. Simulation results showing the shape of the emitted electron beam when the voltage applied to each electrode 840 is 0.00V. Simulation results showing the shape of the emitted electron beam when the voltage applied to each electrode 840 is +2.00V. Simulation results showing the shape of the emitted electron beam when the voltages applied to adjacent electrodes 840a-840c are -0.50V, -0.13V and -0.50V, respectively. FIG. 8B is a cross-sectional view of an electron beam generator 112' according to a modification of FIG. 8A; FIG. 3 is a view of the photocathode 82 viewed from below; 8A and 8B are diagrams showing variations of the electrode 840; 8A and 8B are diagrams showing variations of the electrode 840; 8A and 8B are diagrams showing variations of the electrode 840; 8A and 8B are diagrams showing variations of the electrode 840;

First, the basic configuration of the electron beam irradiation apparatus will be described.

FIG. 1A is a diagram schematically showing the schematic configuration of an electron beam irradiation apparatus. A sample W to be processed by this electron beam irradiation apparatus is a NIL (Nano Imprint Lithography) mask, a photomask, an EUV (Extreme Ultraviolet Lithography) mask, or the like.
It is suitable for processing a mask used for fabricating a fine pattern of 20 nm or less, especially 20 nm or less. Also, the sample W may be a semiconductor wafer of Si, GaAs, or the like.

The electron beam irradiation apparatus includes a column section 11 , a main chamber section 12 provided therebelow, and a control section 13 .

The column section 11 includes a vertically extending cylindrical vacuum tube 111 , an electron beam generator 112 , an aperture 113 , a lens 114 , a deflector 115 , a sensor unit 116 , a gate valve 117 and a turbomolecular pump 118 . , a gate valve 11A, and a particle catcher 11B.

An electron beam generator 112 is provided above the vacuum tube 111 and emits an electron beam downward. A configuration example of the electron beam generator 112 will be described in the seventh embodiment. The aperture 113 is provided below the electron beam generator 112, and the electron beam passes through an opening having a diameter of 2 mm or less formed in the center. A deflector 115 is provided below the lens 114 and can deflect the electron beam. The lens 114 may be an electrostatic lens arranged inside the vacuum tube 111 or a magnetic lens arranged outside the vacuum tube 111 . Also, the deflector 115 may be an electrostatic deflector arranged inside the vacuum tube 111 or a magnetic deflector arranged outside the vacuum tube 111 .

The vacuum tube 111 has a horizontally branched intermediate exhaust line 111a between the electron beam generator 112 and the aperture 113. A sensor unit 116, a gate valve 117 and a turbomolecular pump 118 are mounted on the intermediate exhaust line 111a. are set in order.

With such a configuration, the inside of the vacuum tube 111 can be differentially pumped, and the pressure in the vicinity of the electron beam generator 112 can be made lower than the pressure inside the main chamber section 12 . In addition to the aperture 113, a small-diameter tube (not shown) may be provided below the aperture 113 to adjust the conductance to improve the effect of differential pumping.

FIG. 1B is a schematic cross-sectional view of the sensor unit 116. FIG. In order to reduce the size of the electron beam irradiation apparatus, a plurality of ports 111b radially extend from the intermediate exhaust line 111a, and each port 111b is provided with a pressure monitor 116a, an N ₂ introduction portion 116b, an atmospheric pressure sensor 116c, and the like. . The pressure monitor 116a monitors the pressure inside the vacuum tube 111, monitors the deterioration state of the electron beam generator 112, and determines the timing of replacement.

It is desirable that the diameter d of each port 111b be 1/3 or more of the diameter D of the central portion of the intermediate exhaust line 111a (d/D≧1/3). This is because the pressure monitor 116a cannot accurately monitor the pressure in the vacuum tube 111 if the diameter d of the port 111b is too small.

Returning to FIG. 1A, the gate valve 11A is provided in the vacuum tube 111 between the aperture 113 and the main chamber section 12 so as to be openable and closable. By providing the gate valve 11</b>A, it is possible to separate the vacuum state between the main chamber section 12 and the vacuum tube 111 .

The particle catcher 11B is detachably provided between the gate valve 11A and the main chamber portion 12 within the vacuum tube 111, and prevents particles generated when the gate valve 11A is operated or the like from falling into the main chamber portion 12. to prevent

FIG. 1C is a diagram showing a configuration example of the particle catcher 11B. The particle catcher 11B is composed of a base member 11Ba and an adsorbent 11Bb provided on the base member 11Ba. The adsorbent 11Bb is SiO ₂ gel or the like, and adsorbs particles falling inside the vacuum tube 111 . By providing the particle catcher 11</b>B, it is possible to prevent particles falling inside the vacuum tube 111 from falling on the surface of the sample W placed inside the main chamber section 12 .

Returning to FIG. 1A, the particle catcher 11B can move in and out of the vacuum tube 111 on the optical axis of the electron beam.

The main chamber section 12 has a main chamber 121 which is a vacuum chamber, a gate valve 122 , a turbomolecular pump 123 , a stage 124 , an application pin 125 , an aperture 126 and a measurement unit 127 .

A gate valve 122 for loading and unloading the sample W is provided on the side surface of the main chamber 121 so as to be openable and closable. A turbo-molecular pump 123 for evacuating the interior of the main chamber 121 is provided on the bottom surface of the main chamber 121 .
A stage 124 is provided in the main chamber 121 and a sample W is placed thereon.

A configuration example of the application pin 125 will be described in a fifth embodiment, which will be described later. The irradiation energy is determined according to the difference between the potential of the electron beam generator 112 (eg, −0.2 kV to −5 kV) and the potential of the sample W, but if the potential of the sample W is floating, the irradiation energy becomes unstable. end up Therefore, a constant potential is applied to the sample W by providing an application pin 125 .

Aperture 126 is provided within main chamber 121 and above stage 124 . The aperture 126 is provided with an opening 126a, which defines the shape of the electron beam and which region of the sample W is irradiated with the electron beam.

FIG. 1D is a diagram for explaining the role of the aperture 126. The upper diagram is a schematic side view of the electron beam irradiation device, and the lower diagram is a top view of the sample W and the electron beam to be scanned. The deflector 115 deflects the electron beam so that the electron beam from the electron beam generator 112 scans the sample W. FIG. At this time, the electron beam may not be uniform at the turnaround point of the scan. Therefore, by shielding the electron beam corresponding to the turning point with the aperture 126, the sample W can be uniformly irradiated with the electron beam.

Here, when the distance between the aperture 126 and the surface of the sample W is Lc, and the distance between the edge of the aperture 126a and the edge of the aperture 126 is Lp, it is desirable that Lp/Lc≧1.5. That is, it is desirable to set the aspect ratio of the space between the lower surface of the aperture 126 and the surface of the sample W to 1.5 or more. By designing in this way, electrons reflected from the surface of the sample W are reflected several times and fly to the outer peripheral portion, so that the influence of noise can be reduced.

Returning to FIG. 1A, the measurement unit 127 performs electron beam measurement and is provided inside the main chamber 121 and below the stage 124 . Details of the measurement unit 127 will be described in the fourth embodiment.

The controller 13 has a general controller 131 , an electron beam controller 132 , a peripheral controller 133 and a block manifold 134 .

The general control section 131 controls the operation of the entire electron beam irradiation apparatus including the electron beam control section 132 , the peripheral control section 133 and the block manifold 134 . The overall control unit 131 can be configured with a processor and memory. Various programs to be executed by the processor may be pre-stored in the memory, or may be additionally stored (or updated) later.

The electron beam controller 132 controls irradiation and deflection of the electron beam by controlling the electron beam generator 112 and the deflector 115 . Control examples will be described in the first to third embodiments.
A peripheral control unit 133 controls the turbomolecular pumps 118 and 123, the dry pump 119, and the like.
A block manifold 134 performs opening/closing control (pneumatic control) of the gate valves 117 , 11 A, and 122 .

This electron beam irradiation apparatus operates as follows. When irradiating the sample W with the electron beam, the gate valve 11A is opened to keep the particle catcher 11B off the optical axis of the electron beam. Further, the interior of the vacuum tube 111 and the interior of the main chamber 121 are evacuated. In this state, the electron beam generator 112 emits an electron beam. The electron beam passes through the opening of the aperture 113, is deflected by the deflector 115, passes through the opening of the aperture 126, and reaches the surface of the sample W. FIG. The irradiation area of the electron beam is wide, for example, about 10×10 mm to 500 mm×500 mm.

Next, the scanning of the electron beam on the sample W will be described. In this electron beam irradiation apparatus, the deflector 115 deflects the electron beam in the XY directions (two-dimensional directions on the surface of the sample W) according to the control of the electron beam control unit 132, so that the surface of the sample W is uniformly irradiated. Irradiate with an electron beam.

1E and 1F are explanatory diagrams of control for deflecting an electron beam in the XY directions. More specifically, FIG. 1E is a diagram showing the time change of the coordinates (X coordinate and Y coordinate) of the deflected electron beam, and FIG. 1F is a plan view showing how the electron beam is deflected in the XY directions. (Plan view of the sample W viewed from the electron beam source side). In this specification, for convenience, the X direction may be called the horizontal direction, and the Y direction may be called the vertical direction.

From time t0 to time t1, the electron beam is deflected in a direction in which the X coordinate indicating the electron beam arrival position on the sample W increases (the positive direction of the X coordinate, the right direction in FIG. 1F, also referred to as forward travel) (X1, X2, X3, X4), and then deflected in the direction in which the X coordinate becomes smaller (negative direction, leftward direction in FIG. 1F, also referred to as return path) (X4, X5, X6, X7). At this time, the Y coordinate of the electron beam remains constant at Y1.

Here, as shown in FIG. 1F, the magnitude relationship of the X coordinates is X1<X7<X2<X6<X3<X5<X4. That is, the electron beam is discretely irradiated onto the sample W, and the irradiation positions are alternated between the outward path and the return path. By doing so, the surface of the sample W can be uniformly irradiated with the electron beam.

In the return path, when the X coordinate indicating the arrival position of the electron beam becomes X8 (=X1), the electron beam is deflected in the direction in which the Y coordinate becomes larger (the positive direction of the Y coordinate, the downward direction in FIG. 1F), and the Y coordinate of the electron beam Become Y2.

Similarly, from time t1 to t2, the electron beam is deflected in the direction of increasing the X coordinate and then in the direction of decreasing the X coordinate. At this time, the Y coordinate of the electron beam remains constant at Y2. Then, when the X coordinate becomes X8 (=X1), the electron beam is deflected in the direction in which the Y coordinate becomes larger, and the Y coordinate of the electron beam becomes Y3.

Also, from time t2 to t3, the electron beam is first deflected in the direction of increasing the X coordinate, and then deflected in the direction of decreasing the X coordinate. At this time, the Y coordinate of the electron beam remains constant at Y3. Then, when the X coordinate becomes X8 (=X1), the electron beam is deflected in the direction in which the Y coordinate becomes larger, and the Y coordinate of the electron beam becomes Y4.

Then, from time t3 to t4, the electron beam is first deflected in the direction of increasing the X coordinate, and then deflected in the direction of decreasing the X coordinate. At this time, the Y coordinate of the electron beam remains constant at Y4. Then, when the X coordinate becomes X8 (=X1), the electron beam is deflected in the direction in which the Y coordinate becomes smaller (negative direction of the Y coordinate; upward direction in FIG. 1F), and the Y coordinate of the electron beam becomes Y5.

Similarly, from time t4 to t5, the electron beam is first deflected in the direction of increasing the X coordinate, and then deflected in the direction of decreasing the X coordinate. At this time, the Y coordinate of the electron beam remains constant at Y5. Then, when the X coordinate becomes X8 (=X1), the electron beam is deflected in the direction in which the Y coordinate becomes smaller, and the Y coordinate of the electron beam becomes Y6.

Also, from time t5 to t6, the electron beam is first deflected in the direction of increasing the X coordinate, and then deflected in the direction of decreasing the X coordinate. At this time, the Y coordinate of the electron beam remains constant at Y6. Then, when the X coordinate becomes X8 (=X1), the electron beam is deflected in the direction in which the Y coordinate becomes smaller, and the Y coordinate of the electron beam becomes Y7.

Then, from time t6 to t7, the electron beam is first deflected in the direction of increasing the X coordinate, and then deflected in the direction of decreasing the X coordinate. At this time, the Y coordinate of the electron beam remains constant at Y7. Then, when the X coordinate becomes X8 (=X1), the electron beam is deflected in the direction in which the Y coordinate becomes smaller (negative direction of the Y coordinate; upward direction in FIG. 1F), and the Y coordinate of the electron beam becomes Y1.

Here, as shown in FIG. 1F, the magnitude relationship of the Y coordinates is Y1<Y7<Y2<Y6<Y3<Y5<Y4. In other words, the electron beam is discretely irradiated onto the sample W also in the Y direction, and the irradiation positions are alternated between the outward path and the return path. By doing so, the sample W
The electron beam can be uniformly irradiated on the surface of the

Here, when the main chamber 121 is evacuated, the particle catcher 11B is removed from the optical axis of the electron beam before the turbomolecular pump 123 is activated. As a result, particles adsorbed to the particle catcher 11B can be prevented from falling onto the sample W by leaving the particle catcher 11B under the influence of air currents during evacuation.

A flow showing the flow of processing when a next sample W is transported and irradiated with an electron beam after completion of electron beam irradiation on a certain sample W will be described in detail with reference to FIG. 6C in the fifth embodiment. describe.

[Description of symbols]
11 Column Part 111 Vacuum Tube 111a Intermediate Exhaust Line 112 Electron Beam Generator 113 Aperture 114 Lens 115 Deflector 116 Sensor Unit 116a Pressure Monitor 116b _N2 Introduction Part 116c Atmospheric Pressure Sensor 117 Gate Valve 118 Turbo Molecular Pump 119 Dry Pump 11A Gate Valve 11Aa Base member 11Ab Adsorbent 11B Particle catcher 12 Main chamber 121 Main chamber 122 Gate valve 123 Turbo molecular pump 124 Stage 125 Application pin 126 Aperture 126a Opening 127 Measurement unit 13 Control section 131 Overall control section 132 Electron beam control section 133 Peripheral control section 134 block manifold

A part or all of each embodiment described below can be applied to the electron beam irradiation apparatus described above.

(First embodiment)

[Technical field]
The present embodiment relates to an electron beam irradiation area adjustment method and adjustment system.

[Background technology]
In the electron beam irradiation apparatus, the electron beam from the electron beam generator 112 is deflected by the deflector 115 to irradiate a specific area on the sample W with the electron beam (see FIG. 1A). However, depending on the characteristics of the deflector 115 and the like, the electron beam may irradiate an area different from the intended area.

[Problems to be solved by the present embodiment]
Provided are a method and an adjustment system for adjusting an irradiation area of an electron beam in an electron beam irradiation apparatus.

[Means to solve the problem]

<Aspect 1>
A method for adjusting an irradiation area of an electron beam in an electron beam irradiation apparatus that irradiates an irradiation target by deflecting an electron beam with a deflector, comprising:
an electron beam irradiation step of controlling the deflector based on an electron beam irradiation recipe to irradiate the electron beam while changing the irradiation position with respect to an adjustment plate that detects a current corresponding to the irradiated electron beam;
a current acquisition step of acquiring a current detected from the adjustment plate;
an image forming step of forming image data corresponding to the acquired current value;
a determination step of determining whether an irradiation area of the electron beam is appropriate based on the formed image data;
and a recipe update step of updating the electron beam irradiation recipe when the irradiation area is determined to be inappropriate.

<Aspect 2>
The electron beam irradiation area adjustment method according to aspect 1, wherein the electron beam irradiation step, the current acquisition step, the image forming step, the determination step, and the recipe update step are repeated until the irradiation area is determined to be appropriate.

<Aspect 3>
The electron beam irradiation area adjustment according to mode 1 or 2, wherein the adjustment plate includes a portion that detects a current corresponding to the irradiated electron beam and a portion that does not detect the current even if the electron beam is irradiated. Method.

<Aspect 4>
4. The electron beam irradiation according to any one of modes 1 to 3, wherein the image forming step forms the image data by converting a current value acquired at each time into a gradation of each pixel in the image data. Area adjustment method.

<Aspect 5>
5. The electron beam irradiation area adjustment method according to any one of aspects 1 to 4, wherein the determination step performs determination by comparing formed image data with image data prepared in advance.

<Aspect 6>
the adjustment plate includes a first pattern;
The image data prepared in advance includes a second pattern corresponding to the first pattern,
The irradiation area of the electron beam according to mode 5, wherein the determining step performs determination based on the positional relationship between the first pattern in the formed image data and the second pattern in the previously prepared image data. adjustment method.

<Aspect 7>
the deflector includes an electrode, and the electron beam is deflected according to the voltage of the electrode;
7. The electron beam irradiation area adjustment method according to any one of modes 1 to 6, wherein the electron beam irradiation recipe includes information on the voltage to be applied to the electrodes.

<Aspect 8>
the deflector is an electrostatic deflector including an electrode, the electron beam being deflected according to the voltage of the electrode;
The electron beam irradiation recipe includes information on the voltage to be applied to the electrode,
the adjustment plate includes a first pattern;
The image data prepared in advance includes a second pattern corresponding to the first pattern,
The determining step performs determination based on a positional relationship between the first pattern in the formed image data and the second pattern in the previously prepared image data,
The recipe updating step updates the voltage applied to the electrode in the electron beam irradiation recipe according to the distance between the position of the first pattern and the position of the second pattern in the formed image data. 6. The electron beam irradiation area adjustment method according to any one of 1 to 5.

<Aspect 9>
the deflector is an electromagnetic deflector including a magnetic pole, the electron beam being deflected according to the current of the magnetic pole;
The electron beam irradiation recipe includes information on the current supplied to the magnetic pole,
the adjustment plate includes a first pattern;
The image data prepared in advance includes a second pattern corresponding to the first pattern,
The determining step performs determination based on a positional relationship between the first pattern in the formed image data and the second pattern in the previously prepared image data,
The recipe updating step updates the current supplied to the magnetic poles in the electron beam irradiation recipe according to the distance between the position of the first pattern and the position of the second pattern in the formed image data. 6. The electron beam irradiation area adjustment method according to any one of 1 to 5.

<Aspect 10>
A system for adjusting an irradiation area of an electron beam in an electron beam irradiation apparatus that irradiates an irradiation target by deflecting an electron beam with a deflector,
an adjustment plate for detecting a current corresponding to the irradiated electron beam;
an ammeter for obtaining the current sensed from the adjustment plate;
an image forming unit that forms image data corresponding to the acquired current value;
a determination unit that determines whether or not the irradiation area of the electron beam is appropriate based on the formed image data;
An electron beam irradiation area adjustment system, comprising: a recipe updating unit that updates an electron beam irradiation recipe for controlling the deflector when the irradiation area is determined to be inappropriate.

[Effect of this embodiment]
You can adjust the electron beam.

[Brief description of the drawing]
[FIG. 2A] A diagram showing a schematic configuration of an irradiation area adjustment system 200 in an electron beam irradiation apparatus.
[FIG. 2B] A top view schematically showing the adjustment plate 21. [FIG.
[FIG. 2CA] A diagram schematically showing an irradiation area of an electron beam on the adjusting plate 21. [FIG.
[FIG. 2CB] A diagram schematically showing an irradiation area of an electron beam on the adjustment plate 21. [FIG.
[FIG. 2D] A flowchart showing a procedure for adjusting the irradiation area.
[FIG. 2E] A diagram showing the time change of the voltage applied to the electrode 2115. [FIG.
[Fig. 2FA] A diagram showing the relationship between irradiation area and time in Fig. 2CA.
[FIG. 2FB] A diagram showing the relationship between irradiation area and time in FIG. 2CB.
[Fig. 2GA] A diagram showing temporal changes in the acquired current values.
[Fig. 2GB] A diagram showing temporal changes in the acquired current values.
[FIG. 2HA] A diagram showing image data formed corresponding to the current values shown in FIG. 2GA.
[FIG. 2HB] A diagram showing image data formed corresponding to the current values shown in FIG. 2GA.
[FIG. 2I] A diagram showing the time variation of the adjusted voltage applied to the electrode 2115. [FIG.

[Mode for carrying out the present embodiment]
FIG. 2A is a diagram showing a schematic configuration of an irradiation area adjustment system 200 in an electron beam irradiation apparatus. The irradiation area adjustment system 200 performs adjustment when the sample is not placed on the stage 124 (FIG. 1A), for example, when the electron beam irradiation apparatus is started up.
First, as described with reference to FIG. 1A, the electron beam irradiation apparatus includes an electron beam generator 112, a deflector 115, an electron beam controller 132, and the like.

The deflector 115 in this embodiment is an electrostatic deflector having a plurality of electrodes 2115. More specifically, the electrodes 2115 in the deflector 115 have two electrodes for horizontally deflecting the electron beam on the specimen. It includes an electrode (hereafter referred to as electrode H, not shown) and two electrodes for vertical deflection (hereafter referred to as electrode V, although not shown). The electron beam is deflected according to the voltage applied to these electrodes H and V. FIG.

The electron beam controller 132 also has a beam scanner 26 and a deflector power supply 27 . The beam scanner 26 generates a waveform for deflecting the electron beam based on the electron beam irradiation recipe including information on the voltage applied to the electrode 2115 . The deflector power supply 27 generates a voltage corresponding to the same waveform and applies it to the electrode 2115 .

The irradiation area adjustment system 200 includes an adjustment plate 21 , an ammeter 22 , an image forming section 23 , a determination section 24 and a recipe updating section 25 . Note that the image forming unit 23, the determining unit 24, and the recipe updating unit 25 may be incorporated in the overall control unit 131 of FIG. 1A, and at least part of them may be realized by executing a predetermined program.

The adjustment plate 21 detects a current corresponding to the irradiated electron beam, and is mounted at a predetermined position on the stage 124 (FIG. 1A). That is, the adjustment plate 21 is placed under the sample to be irradiated with the electron beam.

FIG. 2B is a top view schematically showing the adjustment plate 21. FIG. The adjustment plate 21 is, for example, a square with a side of 45 mm. The adjustment plate 21 includes a predetermined pattern, and in the specific example of the figure, a hole 21a is formed as a pattern on the upper left. When the electron beam is applied to a position different from the hole 21a, the adjustment plate 21 detects current. On the other hand, when the electron beam irradiates the hole 21a, the adjustment plate 21 detects no current.

2CA and 2CB are diagrams schematically showing the irradiation area of the electron beam on the adjustment plate 21. FIG. It is intended to irradiate the electron beam on the dashed area of FIG. 2CA. However, as indicated by the dashed line in FIG. 2CB, the electron beam may irradiate an area different from the intended area (an area shifted to the upper left in the figure). Therefore, in the present embodiment, the state of FIG. 2CB is adjusted to the state of FIG. 2CA.

Returning to FIG. 2A, the ammeter 22 in the irradiation area adjustment system 200 is connected between the adjustment plate 21 and a ground terminal (not shown) to acquire the current detected by the adjustment plate 21 . The acquired current value is detected by the image forming unit 23 . The ammeter 22 sequentially acquires the current detected at each time.

The image forming unit 23 forms image data corresponding to the current acquired by the ammeter 22 . Specifically, it can be done as follows. First, the image forming section 23 converts the current value at each time into a voltage value. Subsequently, the image forming unit 23 converts the voltage value into, for example, 256 levels of gradation. Then, the image forming unit 23 sets the obtained gradation to the gradation of each pixel of the image data.

For example, the adjustment plate 21 detects the current at the time when the electron beam is applied to a position different from the hole 21a. Therefore, the voltage value also increases, and the gradation becomes 255, for example. Therefore, the pixel corresponding to this time becomes bright. On the other hand, the adjustment plate 21 detects no current at the time when the electron beam is irradiated to the hole 21a. Therefore, the voltage value also becomes small, and the gradation becomes 0, for example. Therefore, the pixels corresponding to this time are dark.

Based on the image data formed by the image forming unit 23, the determination unit 24 determines whether or not the irradiation area of the electron beam is appropriate. Specifically, the determination unit 24 holds in advance image data (hereinafter referred to as template image data) to be formed when the irradiation area of the electron beam is appropriate, and the image data formed by the image forming unit 23 is stored in advance. Determined by comparing with More specifically, the determination unit 24 performs the determination based on the positional deviation between the predetermined pattern (for example, corresponding to the hole 21a in FIG. 2B) in the formed image data and the predetermined pattern in the template image data.

The recipe updating unit 25 updates the electron beam irradiation recipe in consideration of the positional deviation when it is determined that the irradiation area of the electron beam is inappropriate. The updated electron beam irradiation recipe is notified to the beam scanner 26, and thereafter the updated electron beam irradiation recipe is used. A specific update method will be described later.

FIG. 2D is a flowchart showing a procedure for adjusting the irradiation area. In order to irradiate the adjustment plate 21 with the electron beam while changing the irradiation position (step S21), the electron beam controller 132 controls the voltage applied to the electrode 2115 in the deflector 115 based on the electron beam irradiation recipe. To simplify the explanation, it is assumed that the irradiation area of the electron beam is scanned as follows, although it is different from the explanation of FIGS. 1E and 1F.

FIG. 2E is a diagram showing changes in voltage applied to electrode 2115 over time. More specifically, the upper part of FIG. 2E shows the time change of the voltage applied to the electrode H for horizontally deflecting the electron beam, and the lower part shows the electrode H for vertically deflecting the electron beam. It shows the time change of the voltage applied to V. FIG. This waveform is included in the electron beam irradiation recipe. 2FA and 2FB are diagrams showing the relationship between irradiation area and time in FIGS. 2CA and 2CB, respectively.

From time t10 to t20 in FIG. 2E, the voltage applied to the electrode V is constant (eg -3V), and the voltage applied to the electrode H increases linearly from -2V to 2V, for example. Therefore, as shown in FIGS. 2FA and 2FB, from time t10 to t20, the electron beam irradiation position is constant in the vertical direction and moves in the horizontal direction (referred to as the first line).

At time t20 in FIG. 2E, the voltage applied to electrode V increases (eg, −2.25V). The voltage applied to the electrode H increases linearly from time t20 to t30. Therefore, as shown in FIGS. 2FA and 2FB, from time t20 to t30, the irradiation position of the electron beam is constant in the vertical direction at a different position from time t10 to t20, and moves in the horizontal direction (second line called). After that, the scanning of the irradiation area is similarly completed up to the fifth line.

Returning to FIG. 2D, the ammeter 22 acquires the current detected from the adjustment plate 21 at each time (step S22).
FIG. 2GA is a diagram showing temporal changes in the acquired current values, and corresponds to FIG. 2FA.

At times t10 to t20 of the first line, the electron beam is applied to the position of the adjustment plate 21 that is not the hole 21a (FIG. 2FA). Therefore, a constant current value is obtained from time t10 to t20 (FIG. 2GA). The same applies to times t20 to t30 of the second line.

In the third line, from time t30 to t35, the electron beam is applied to a position other than the hole 21a of the adjustment plate 21 (FIG. 2FA), so the same current value as at time t10 to t30 is obtained (FIG. 2GA). On the other hand, from time t35 to time t36, since the hole 21a of the adjustment plate 21 is irradiated with the electron beam (FIG. 2FA), almost no current flows (FIG. 2GA). At subsequent times t35 to t40, the electron beam is applied to a position other than the hole 21a of the adjusting plate 21, so the same current value as at times t10 to t40 is obtained (FIG. 2GA).

Times t40 to t50 for the fourth line and times t50 to t60 for the fifth line are the same as those for the first and second lines. From the above, the current values shown in FIG. 2GA are obtained.

FIG. 2GB is a diagram showing temporal changes in the acquired current values, and corresponds to FIG. 2FB.
During the time t10 to t20 of the first line, there is no adjustment plate 21 at the position irradiated with the electron beam (FIG. 2FB), so that almost no current flows (FIG. 2GB).

In the second line, between times t20 and t21, there is no adjustment plate 21 at the position where the electron beam is irradiated (FIG. 2FB), so almost no current flows (FIG. 2GB). During subsequent times t21 to t30, the electron beam is applied to a position other than the hole 21a of the adjustment plate 21, so a constant current value is obtained (FIG. 2GB). The same is true for the third line.

In the fourth line, between times t40 and t41, there is no adjustment plate 21 at the position where the electron beam is irradiated (FIG. 2FB), so almost no current flows (FIG. 2GB). At subsequent times t41 to t46, the electron beam is applied to a position other than the hole 21a of the adjustment plate 21, so the same current value as at times t21 to t30 is obtained (FIG. 2GB). At subsequent times t46 to t47, the hole 21a of the adjustment plate 21 is irradiated with the electron beam (FIG. 2FB), so that almost no current flows (FIG. 2GB). From time t47 to t50 thereafter, the electron beam is applied to a position other than the hole 21a of the adjustment plate 21, so the same current value as at time t21 to t30 is obtained (FIG. 2GB).

The times t50 to t60 for the fifth line are the same as those for the second and third lines. From the above, the current values shown in FIG. 2GB are obtained.

Returning to FIG. 2D, the image forming unit 23 forms image data corresponding to the acquired current value (
step S23).

FIG. 2HA is a diagram showing image data formed corresponding to the current values shown in FIG. 2GA. Current values at times t10 to t20 correspond to pixel values of the first line of the image data. Since the current value is large from time t10 to t20, each pixel value of the first line is large and bright. Considering the same below, in the image data of FIG. 2HA, only pixels corresponding to times t35 to t36 on the third line become dark. This dark location corresponds to hole 21a in FIG. 2B.

This image data is image data when the intended area shown in FIG. 2C is irradiated with the electron beam, that is, template image data. The template image data can be created on a desk based on the pattern of the intended irradiation area on the adjustment plate 21, and the template image data is stored in advance in the determination unit 24 described below. The template image data includes the pattern (holes 21a) of the adjustment plate 21 and the corresponding pattern 21b.

FIG. 2HB is a diagram showing image data formed corresponding to the current values shown in FIG. 2GB. In FIG. 2GB, since almost no current flows from time t10 to t20, the first line of the image data in FIG. 2HB is dark. In addition, since almost no current flows during times t20 to t21, t30 to t31, t40 to t41, and t50 to t51, the left edge of the same image data is also dark. Since almost no current flows even at times t46 to t47 on the fourth line, a dark pattern 21b' is generated in part of the fourth line. This pattern 21b' corresponds to the pattern (hole 21a) of the adjustment plate 21. As shown in FIG.

Returning to FIG. 2D, the determination unit 24 determines whether or not the irradiation area of the electron beam is appropriate (step S24). Specifically, the determination unit 24 performs pattern matching between the pre-stored template image data and the image data formed in step S23.

Assume that the template image data is shown in FIG. 2HA and the image data formed in step S23 is shown in FIG. 2HB. The determination unit 24 calculates the positional relationship, that is, the distance D between the pattern 21b in the template image data of FIG. 2HA and the pattern 21b' in the image data of FIG. 2HB. Then, if the distance D is equal to or less than a predetermined allowable value, the determination unit 24 determines that the irradiation area is appropriate (YES in step S24 in FIG. 2D), and ends the adjustment.

On the other hand, if the distance D exceeds the allowable value, it is determined that the irradiation area is inappropriate (NO in step S24). In this case, the recipe updating unit 25 updates the electron beam irradiation recipe (step S25). More specifically, the recipe updater 25 changes the waveform generated by the beam scanner 26 (for example, the voltage waveform shown in FIG. 2E). The greater the distance D, the greater the amount of change.

For example, the number of pixels of each image data is 256×256, the position of the pattern 21b in the template image data (FIG. 2HA) is (128, 128), and the pattern 21b′ in the image data (FIG. 2HB) formed in step S23 is is at (192, 192). In this case, the illuminated area is shifted horizontally and vertically by 25% of the image size. Therefore, the waveform shown in FIG. 2E is adjusted by 25%. That is, in FIG. 2E, the voltage applied to the electrode H in the horizontal direction is in the range of -2V to 2V, but this is changed to -1V to 3V (upper part of FIG. 2I). Although the voltage applied to the electrode V in the vertical direction is in the range of -3V to 1V, it is changed to -2V to 2V (bottom of FIG. 2I). As a result, the irradiation area of the electron beam moves in the horizontal direction and the vertical direction, so that an appropriate area is irradiated with the electron beam.

Although the adjustment may be terminated at this point, preferably, steps S21 and subsequent steps are repeated until it is determined to be appropriate in step S24. During this repetition, in step S21, the electron beam irradiation recipe updated in step S25 is applied.

As described above, in this embodiment, the irradiation area of the electron beam can be adjusted by using the adjustment plate 21 on which the predetermined pattern is formed. This method of adjustment eliminates the need to use an actual mask, thus avoiding wastage of the mask.

In this embodiment, the deflector 115 is an electrostatic deflector, but the deflector 115 may be a magnetic deflector having a plurality of magnetic poles. In this case, the deflector power supply 27 supplies a current to each magnetic pole for deflecting the electron beam.

Further, the scan shown in FIG. 2E was performed for the sake of simplification of the explanation, but the same consideration may be applied to the case where the scans shown in FIGS. 1E and 1F are performed.

[Description of symbols]
200 irradiation area adjustment system 21 adjustment plate 21a hole 21b, 21b' pattern 22 ammeter 23 image forming unit 24 determination unit 25 recipe update unit 26 beam scanner 27 deflector power supply 112 electron beam generator 115 deflector 2115 electrode 131 overall control unit 132 electron beam controller

(Second embodiment)

[Technical field]
The present embodiment relates to an electron beam irradiation apparatus and a method for correcting an irradiation area of the electron beam.

[Background technology]
As described with reference to FIG. 1F, the electron beam controller 132 controls the deflector 115 so that the irradiation area (position where the electron beam reaches) is rectangular (including square) in a normal electron beam irradiation apparatus. However, depending on the characteristics of the deflector 115, the irradiation area may not be rectangular as intended.

[Problems to be solved by the present embodiment]
An object of the present embodiment is to provide an electron beam irradiation apparatus and a method for correcting the electron beam irradiation area that can approximate the irradiation area to a rectangular shape when the irradiation area of the electron beam is not as rectangular as intended. .

[Means to solve the problem]

<Aspect 1>
An electron beam from an electron beam generator is scanned in a first direction by applying a voltage V1(t) that varies with time t to the first electrode, and a voltage V2(t) that varies with time t is applied to the second electrode. In an electron beam irradiation apparatus intended to irradiate an electron beam with a rectangular area as a target by scanning in a second direction orthogonal to the first direction, the irradiation area of the electron beam is a rectangle When it is a roughly parallelogram distorted in the first direction instead of
By applying a voltage V1(t)+kV2(t) (k is a constant) to the first electrode and applying a voltage V2(t) to the second electrode, the irradiation area of the electron beam is corrected to be rectangular. A method for correcting an irradiation area of an electron beam.
When the irradiation region is distorted in the first direction, the irradiation region can be corrected by applying voltage V1(t)+kV2(t) to the first electrode for scanning the electron beam in the first direction.

<Aspect 2>
The electron beam irradiation area correction method according to mode 1, wherein the k is set so that the electron beam irradiation area approaches a rectangle.
As a result, the illuminated area approaches a rectangle.

<Aspect 3>
3. The electron beam irradiation region correction method according to mode 1 or 2, wherein the absolute value of k is set larger as the distortion in the first direction increases.
As a result, the illuminated area approaches a rectangle.

<Aspect 4>
The voltage V2(t) repeats N0 times that the voltage V2(t) becomes a certain value and changes to another value after the period T0 has elapsed,
The voltage V1(t) repeats the linear change with the period T0 as a cycle N0 times,
4. The electron beam irradiation area correction method according to any one of modes 1 to 3, wherein said T0 and N0 respectively correspond to the length of said rectangle in said first direction and said length of said rectangle in said second direction.
When the first direction and the second direction are the horizontal direction and the vertical direction, respectively, the horizontally distorted irradiation area can be corrected into a rectangular shape.

<Aspect 5>
The voltage V1(t) repeats N0 times that the voltage V1(t) becomes a certain value and changes to another value after the period T0 has elapsed,
The voltage V2(t) repeats the linear change with the period T0 as a cycle N0 times,
4. The electron beam irradiation area correction method according to any one of modes 1 to 3, wherein the periods T0 and N0 correspond to the lengths of the rectangle in the second direction and the lengths in the first direction, respectively.
When the first direction and the second direction are the vertical direction and the horizontal direction, respectively, the vertically distorted illumination area can be corrected to be rectangular.

<Aspect 6>
An electron beam from an electron beam generator is scanned in a first direction by applying a voltage V1(t) that varies with time t to the first electrode, and a voltage V2(t) that varies with time t is applied to the second electrode. In an electron beam irradiation apparatus intended to irradiate an electron beam targeting a rectangular area by scanning in a second direction orthogonal to the first direction by applying
applying a voltage V1(t)+kV2(t) (k is a constant) to the first electrode when the irradiation area of the electron beam is not a rectangle but a substantially parallelogram distorted in the first direction; An electron beam irradiation apparatus comprising an electron beam controller for applying a voltage V2(t) to the second electrode, thereby correcting the irradiation area of the electron beam so as to be rectangular.
When the irradiation region is distorted in the first direction, the irradiation region can be corrected by applying voltage V1(t)+kV2(t) to the first electrode for scanning the electron beam in the first direction.

<Aspect 7>
an electron beam generator for generating an electron beam;
a first electrode that deflects the electron beam from the electron beam generator in a first direction;
a second electrode that deflects the electron beam from the electron beam generator in a second direction orthogonal to the first direction;
an electron beam controller for controlling the voltage applied to the first electrode and the second electrode;
An electron beam from an electron beam generator is scanned in the first direction by applying a voltage V1(t) that varies with time t to the first electrode, and a voltage V2(t) that varies with time t is applied to the first electrode. By scanning in the second direction by applying voltage to the second electrode, the irradiation area of the electron beam is not rectangular but in the first direction, although it is intended to irradiate the electron beam with a rectangular area as a target. When it is a distorted approximate parallelogram,
The electron beam controller applies a voltage V1(t)+kV2(t) (where k is a constant) to the first electrode and a voltage V2(t) to the second electrode, thereby generating an electron beam. An electron beam irradiation device that corrects the irradiation area so that it becomes a rectangle.
When the irradiation region is distorted in the first direction, the irradiation region can be corrected by applying voltage V1(t)+kV2(t) to the first electrode for scanning the electron beam in the first direction.

[Effect of this embodiment]
The irradiation area of the electron beam can be approximated to a rectangle.

[Brief description of the drawing]
[FIG. 3A] A diagram schematically showing electron beam irradiation regions 200, 200'.
FIG. 3B schematically shows voltages Vv(t) and Vh(t) respectively applied to electrodes V and H in the deflector 115 to obtain the illuminated area 200 of FIG. 3A;
[FIG. 3C] A diagram schematically showing voltages Vv(t) and Vh(t)+kVv(t) applied to electrodes V and H, respectively, for correcting horizontal distortion of the irradiation region 200'.
[FIG. 3D] A diagram schematically showing irradiation regions 200, 200'' of electron beams.
[FIG. 3E] A diagram schematically showing voltages Vv(t)+kVh(t), Vh(t) applied to the electrodes V, H, respectively, for correcting the vertical distortion of the irradiation region 200''.

[Mode for carrying out the present embodiment]
The left diagram of FIG. 3A is a diagram schematically showing an irradiation area 200 of an electron beam, which is a target. As shown in the figure, the irradiation area 200 of the target is rectangular, but in practice the electron beam is irradiated discretely (see FIG. 1F). A unit of irradiation is called a line. The number of dots (corresponding to the horizontal length) in the irradiation area 200 is Lh (5 in the example of FIG. 2A), and the number of lines (corresponding to the vertical length) is Lv (5 in the example of FIG. 2A). ).

FIG. 3B is a diagram schematically showing voltages Vv(t) and Vh(t) respectively applied to the electrodes V and H in the deflector 115 to obtain the irradiation region 200 of FIG. 3A. schematically shows the relationship between time t and voltages Vv(t) and Vh(t) applied to electrodes V and H, respectively. Electrodes V and H in the deflector 115 are electrodes for deflecting the electron beam in the vertical and horizontal directions, respectively. Also, these voltages Vv(t) and Vh(t) are controlled by the electron beam controller 132 (FIG. 1A).

When voltage Vv(t) is set to a certain value at a certain time, it remains the same value for a predetermined period T0, and is set to another value after the period T0 has elapsed. This is repeated N0 times (5 times in the example shown in the figure). The voltage Vv(t) corresponds to the vertical position (line number) in the irradiation area 200, and more specifically, the higher the value of the voltage Vv(t), the closer to the lower end in the vertical direction. Therefore, by applying such a voltage Vv(t) to the electrode V, the electron beam is scanned in the vertical direction. Here, the period T0 corresponds to the number of dots (horizontal length) Lh of the irradiation area 200 . Also, the number of repetitions N0 corresponds to the number of lines (length in the vertical direction) Lv.

The voltage Vh(t) linearly changes with the period T0 as a cycle. More specifically, voltage Vh(t) linearly increases in the first half of period T0 and linearly decreases with the same slope in the second half of period T0. This is again repeated N0 times. The voltage Vh(t) corresponds to the horizontal position (number of dots) in the irradiation area 200. More specifically, the larger the value of the voltage Vh(t), the closer to the right end in the horizontal direction. Therefore, by applying such a voltage Vh(t) to the electrode H, the electron beam is scanned in the horizontal direction.

It is intended that the voltages Vv(t) and Vh(t) shown in FIG. 3B are applied to the electrodes V and H, respectively, so that the illuminated area 200 is rectangular as shown in FIG. 3A. However, depending on the characteristics of the deflector 115, the irradiation area 200 may be distorted in the horizontal direction. Therefore, in this embodiment, when the irradiation area 200 is distorted in the horizontal direction, correction is performed so that the irradiation area 200 becomes a rectangle.

The right diagram of FIG. 3A is a diagram schematically showing a horizontally distorted electron beam irradiation region 200'. As shown, the illumination area 200' is a parallelogram. There is no vertical displacement in this parallelogram, as indicated by the dash-dot line. Therefore, in the vertical direction, the electron beam controller 132 may apply the voltage Vv(t) in FIG. 3B to the electrode V as it is (see the upper diagram in FIG. 3C).

On the other hand, as shown by the chain double-dashed line in the figure, the second line is horizontally shifted to the right by A from the first line, and more generally n (n=1 to Lv). The line is shifted to the right by (n-1)*A. That is, the amount of deviation increases in proportion to the vertical position, and this vertical position corresponds to the voltage Vv(t) as described above. Therefore, the electron beam controller 132 should apply the voltage Vh(t)+kVv(t) to the electrode H (see the lower diagram in FIG. 3C).

Here, k is a constant, and is set so that the electron beam irradiation area 200' approaches a rectangle (preferably a rectangle). As shown in the right diagram of FIG. 3A, when the irradiation area 200′ is a parallelogram distorted to the right side (the side where the voltage Vh(t) is large), the horizontal position of the second and subsequent lines is to the left side. k is set to a negative value to shift . On the other hand, if the irradiation area 200′ is a parallelogram distorted to the left (to the side where the value of the voltage Vh(t) is small), k is a positive value to shift the horizontal position of the second and subsequent lines to the right. is set to The larger the distortion amount A is, the larger the absolute value of k is set.

As described above, in this embodiment, when the irradiation region 200 is distorted in the horizontal direction, the voltage Vv(t) is applied to the electrode V that deflects the electron beam in the vertical direction, and the electrode H that deflects the electron beam in the horizontal direction is applied. is applied with a voltage Vh(t)+kVv(t). This results in a distorted irradiation area 200'.
can approximate a rectangle.

The embodiments described above assume that the irradiation region 200 is distorted in the horizontal direction. In contrast, the embodiment described below assumes that the irradiation area 200 is distorted in the vertical direction. The following description will focus on the differences.

The upper diagram of FIG. 3D is a reprint of the left diagram of FIG. 3A, and the lower diagram of FIG. 3D is a diagram schematically showing an irradiation region 200'' of an electron beam distorted in the vertical direction. As shown, the illumination area 200'' is a parallelogram. There is no horizontal displacement in this parallelogram, as indicated by the dashed line. Therefore, in the horizontal direction, the electron beam controller 132 should apply the voltage Vh(t) in FIG. 3B to the electrode H (see the lower diagram in FIG. 3E).

On the other hand, as shown by the chain double-dashed line in the same figure, when the first dot is used as a reference, the second dot is shifted upward by B in the horizontal direction. ) dot is shifted upward by (n−1)*B. That is, the amount of deviation increases in proportion to the horizontal position, and this horizontal position corresponds to the voltage Vh(t) as described above. Therefore, the electron beam controller 132 should apply the voltage Vv(t)+kVh(t) to the electrode V (see the upper diagram of FIG. 3E).

Here, k is a constant, and is set so that the electron beam irradiation area 200'' approaches a rectangle (preferably a rectangle). As shown in the lower diagram of FIG. 3D, when the irradiation area 200'' is a parallelogram distorted upward (the side where the value of the voltage Vv(t) is small), the vertical position of the second and subsequent dots is downward. To shift to the side, k is set to a positive value. On the other hand, when the irradiation area 200'' is a parallelogram distorted downward (the side where the voltage Vv(t) is large), k is Set to a negative value. The larger the distortion amount B is, the larger the absolute value of k is set.

As described above, in this embodiment, when the irradiation region 200 is distorted in the vertical direction, the voltage Vh(t) is applied to the electrode H that deflects the electron beam in the horizontal direction, and the electrode V that deflects the electron beam in the vertical direction is applied. is applied with a voltage Vv(t)+kVh(t). Thereby, the distorted irradiation area 200'' can be approximated to a rectangle.

[Description of symbols]
300, 300', 300'' irradiation area

(Third Embodiment)

[Technical field]
The present embodiment relates to an electron beam irradiation apparatus, an electron beam control method, and a program.

[Background technology]
The etching resistance of a resist mask is improved by irradiating an electron beam from an electron beam irradiation apparatus.

[Problems to be solved by the present embodiment]

The etching rate of plasma etching is not spatially uniform, but has a predetermined distribution (for example, the etching rate is high near the center). For this reason, when the sample surface is uniformly irradiated with an electron beam from an electron beam irradiation device to uniformly improve the etching resistance of the resist over the entire surface, a difference in the etching amount occurs according to the distribution of the etching rate. There is a problem.

Therefore, an object of the present embodiment is to provide an electron beam irradiation apparatus, an electron beam control method, and a program capable of reducing variations in the etching amount caused by the etching rate distribution.

[Means to solve the problem]
<Aspect 1>
a deflector for deflecting the electron beam;
a controller that controls the deflector to scan the electron beam;
with
The controller moves the electron beam in the first scanning direction at a moving speed in the first scanning direction in the first region in a second region having a lower etching rate than the first region. An electron beam irradiation device controlling the deflector to be slower than speed.

With this configuration, the movement of the electron beam in the first scanning direction is slower in the first region than in the second region, so that the dose of the electron beam is greater than in the second region, and the resist in the first region has a higher etching resistance than the second region. As a result, even if the etching rate of the first region is higher than that of the second region, the etching resistance of the resist is higher than that of the second region. It is possible to reduce the difference in the etching amount according to the distribution.

<Aspect 2>
the deflector is provided with a first electrode for scanning the electron beam in the first scanning direction;
The control unit controls the change per unit time of the voltage applied to the first electrode in the first period of scanning the first region to be the above-mentioned voltage in the second period of scanning the second region. The electron beam irradiation apparatus according to mode 1, wherein the deflector is controlled so as to be smaller than the change per unit time of the voltage applied to the first electrode.

With this configuration, the movement of the electron beam in the first scanning direction is slower in the first period than in the second period. The etching resistance of the resist in the region irradiated with the electron beam becomes higher than the etching resistance of the resist in the region irradiated with the electron beam during the second period. Thus, even if the etching rate of the region irradiated with the electron beam during the first period is high, the etching resistance of the resist is high. It is possible to reduce the resulting variation in etching amount.

<Aspect 3>
The second period is divided into a first half period and a second half period,
The electron beam irradiation apparatus according to aspect 2, wherein the first period is a period sandwiched between a first half period of the second period and a second half period of the second period.

<Aspect 4>
The electron beam irradiation apparatus according to any one of Modes 1 to 3, wherein the first region is a region in which an etching rate exceeds a threshold.

<Aspect 5>
The electron beam irradiation apparatus according to any one of aspects 1 to 3, wherein the first region is set substantially in the center of the substrate.

<Aspect 6>
The electron beam irradiation device according to any one of aspects 1 to 5, wherein the first region is substantially circular.

<Aspect 7>
The electron beam irradiation device according to any one of modes 1 to 5, wherein the first area is a quadrilateral.

<Aspect 8>
The electron beam irradiation apparatus according to any one of modes 1 to 7, wherein the first scanning direction is a horizontal direction.

<Aspect 9>
An electron beam control method executed by an electron beam irradiation apparatus comprising a deflector for deflecting an electron beam and a controller for controlling the deflector and scanning the electron beam,
The moving speed of the electron beam in the first scanning direction within the first region is lower than the moving speed of the electron beam in the first scanning direction in the second region having a lower etching rate than the first region. An electron beam control method comprising the step of controlling the electron beam as described above.

With this configuration, the movement of the electron beam in the first scanning direction is slower in the first region than in the second region, so that the dose of the electron beam is greater than in the second region, and the resist in the first region has a higher etching resistance than the second region. As a result, even if the etching rate of the first region is higher than that of the second region, the etching resistance of the resist is higher than that of the second region. It is possible to reduce the difference in the etching amount according to the distribution.

<Aspect 10>
A program for controlling a deflector to function as a controller for scanning an electron beam,
The controller moves the electron beam in the first scanning direction at a moving speed in the first scanning direction in the first region in a second region having a lower etching rate than the first region. A program that controls the electron beam to be slower than speed.

With this configuration, the movement of the electron beam in the first scanning direction is slower in the first region than in the second region, so that the dose of the electron beam is greater than in the second region, and the resist in the first region has a higher etching resistance than the second region. As a result, even if the etching rate of the first region is higher than that of the second region, the etching resistance of the resist is higher than that of the second region. It is possible to reduce the difference in the etching amount according to the distribution.

[Effect of this embodiment]

According to this embodiment, in the first region, the movement of the electron beam in the first scanning direction is slower than in the second region. In the region 2, the etching resistance of the resist mask is higher than that in the second region when the electron beam is moved in the first scanning direction. Accordingly, even if the etching rate of the first region is higher than that of the second region, the etching resistance of the resist mask is higher than that of the second region. It is possible to reduce the difference in etching amount according to the distribution of .

[Brief description of the drawing]
[FIG. 4A] A diagram schematically showing an irradiation region 41 of an electron beam.
[FIG. 4B] A diagram schematically showing voltages Vh(t) and Vv(t) respectively applied to electrodes H and V in the deflector 115 to obtain the irradiation region 41 of FIG. 4A.
[FIG. 4C] A diagram schematically showing an irradiation region 42 of an electron beam.
[FIG. 4D] A diagram schematically showing voltages Vh(t) and Vv(t) respectively applied to electrodes H and V of the deflector 115 between points 4P1 and 4P2 in the irradiation region 42 of FIG. 4C.
[FIG. 4E] A diagram schematically showing voltages Vh(t) and Vv(t) respectively applied to electrodes H and V of the deflector 115 between points 4P2 and 4P3 in the irradiation region 42 of FIG. 4C.

[Mode for carrying out the present embodiment]
FIG. 4A is a diagram schematically showing an irradiation region 41 of an electron beam as a target. The irradiation area 41 is part of the substrate on which the layer to be etched is formed. Although the irradiation area 41 of the target is rectangular as shown, in practice, for example, the electron beam is irradiated discretely at the positions of the points in FIG. 4A. As indicated by the polygonal line in FIG. 4A, the electron beam is scanned sequentially from the upper left to the lower right in FIG. 4A.

As an example, the irradiation region 41 is divided into a first region 411 and a second region 412 having a lower etching rate than the first region 411 . The first region 411 is a region where the etching rate exceeds the threshold and is set substantially in the center of the substrate. Here, as an example, the first region 411 is rectangular. In the area of the second area 412 located above the first area 411, the vertical position is changed and five lines are scanned in the horizontal direction. After that, the area including the first area 411 is scanned by 11 lines, for example, in the horizontal direction while changing the position in the vertical direction. After that, in the area located under the first area 411 in the second area 412, the vertical position is changed and five lines are scanned in the horizontal direction.

As shown in FIG. 4A, in the first region 411, the horizontal dot spacing is narrower than in the outer regions. That is, the moving speed of the electron beam in the horizontal direction within the first region 411 in FIG. 4A is slower than the moving speed of the electron beam in the horizontal direction outside the first region 411 in FIG. 4A.

The processing of the control unit 13 at this time will be described. The controller 13 operates the deflector so that the horizontal movement speed of the electron beam in the first region 411 of FIG. 4A is lower than the horizontal movement speed of the electron beam in the second region 412 of FIG. 4A. 115. With this configuration, the horizontal movement of the electron beam is slower in the first region 411 in FIG. 4A than in the second region 412 in FIG. Therefore, the etching resistance of the resist is higher in the first region 411 of FIG. 4A than in the second region 412 of FIG. 4A. As a result, even if the etching rate of the first region 411 in FIG. 4A is higher than that of the second region 412, the etching resistance of the resist is high, so the amount etched by plasma etching can be reduced. It is possible to reduce the difference in the etching amount according to the distribution.

In this embodiment, as an example, a case where the deflector 115 is an electrostatic deflector will be described. FIG. 4B is a diagram schematically showing voltages Vh(t) and Vv(t) respectively applied to electrodes H and V in deflector 115 to obtain irradiation region 41 of FIG. 4A. More specifically, the relationship between time t and voltages Vh(t) and Vv(t) applied to electrodes H and V, respectively, is shown schematically. Electrodes H and V in the deflector 115 are electrodes for deflecting the electron beam in the horizontal and vertical directions, respectively. These voltages Vh(t) and Vv(t) are controlled by an electron beam controller 132 (FIG. 1A) in the controller 13. FIG. In the following, for the sake of simplification, it is assumed that the control unit 13 controls.

When voltage Vv(t) is set to a certain value at a certain time, it remains the same value for a predetermined period T1, and is set to a value larger by the difference voltage ΔV1 after the lapse of this period T1. This is repeated N1 times (five times, corresponding to five lines in the example shown in the figure). The voltage Vv(t) corresponds to the vertical position (line number) in the irradiation area 41, and more specifically, the higher the value of the voltage Vv(t), the closer to the lower end in the vertical direction. Therefore, when such a voltage Vv(t) is applied to the electrode V, the position of the electron beam in the vertical direction changes.

In the meantime, the voltage Vh(t) linearly changes with the period T1 as a cycle. More specifically, voltage Vh(t) linearly increases with a first slope during this period T1. This is again repeated N1 times. The voltage Vh(t) corresponds to the horizontal position (number of dots) in the irradiation area 41. More specifically, the larger the value of the voltage Vh(t), the closer to the right end in the horizontal direction. Therefore, by applying such a voltage Vh(t) to the electrode H, the irradiation position of the electron beam shifts in the horizontal direction.

After that, when the voltage Vv(t) is set to a value greater by the differential voltage ΔV1, it remains the same value for a predetermined period T2 (>T1), and is set to a value greater by the differential voltage ΔV1 after the lapse of this period T2. be. This is repeated N2 times (11 times corresponding to 11 lines in the example shown in the figure).

In the meantime, the voltage Vh(t) changes in a polygonal line with the period T2 as a cycle. More specifically, the voltage Vh(t) linearly increases with a first slope in the first half period T21, linearly increases with a second slope smaller than the first slope in the middle period T22, and rises linearly with a second slope in the second half period T22. In period T23, it linearly increases with the same first slope as in period T21 in the first half. That is, the change in voltage Vh(t) per unit time in period T22 (that is, the slope of voltage Vh(t) in FIG. 4B) is the change in voltage Vh(t) per unit time in periods T21 and T23 (that is, slope of voltage Vh(t) in FIG. 4B). This is also repeated N2 times (11 times, corresponding to 11 lines in the example shown in the figure).

After that, when the voltage Vv(t) is set to a value greater by the difference voltage ΔV1, it remains the same value for a predetermined period T1, and is set to a value greater by the difference voltage ΔV1 after the lapse of this period T1. This is repeated N1 times (five times, corresponding to five lines in the example shown in the figure).
In the meantime, the voltage Vh(t) linearly changes with the period T1 as a cycle. More specifically, the voltage Vh(t) increases linearly with a first slope during the period T1, and returns to the initial value Vh0 after the period T1. This is again repeated N1 times.

Specifically, in the present embodiment, the control unit 13 determines that the change per unit time of the voltage Vh(t) in the period T22 of FIG. The deflector 115 is controlled so as to be less than the change in perimeter. With this configuration, in period T22 in FIG. 4B, the horizontal movement of the electron beam is slower than in periods T21 and T23 in FIG. 4B. , the etching resistance of the resist in the regions irradiated with the electron beam during periods T21 and T23 in FIG. 4B. As a result, even if the etching rate of the region irradiated with the electron beam during the period T22 in FIG. 4B is high, the etching resistance of the resist is high. It is possible to reduce the difference in the etching amount according to .

In this embodiment, the moving speed of the electron beam is slowed down in the horizontal direction. In that case, the controller 13 controls the moving speed of the electron beam in the first scanning direction in the first region 411 to be lower than the moving speed of the electron beam in the first scanning direction in the second region 412. , may control the deflector 115 . Here, the first scanning direction is any direction including the horizontal direction and the vertical direction.

With this configuration, the horizontal movement of the electron beam is slower in the first region 411 than in the first region 412 , so that the electron beam irradiation amount is greater than in the second region 412 . , the etching resistance of the resist is higher in the horizontal movement of the electron beam than in the second region 412 . As a result, even if the etching rate of the first region 411 is higher than that of the second region 412, the etching resistance of the resist is higher than that of the second region 412, so the amount etched by plasma etching can be reduced. It is possible to reduce the difference in the etching amount according to the etching rate distribution.

Further, as a specific process in this case, the control unit 13 controls the unit time of the voltage applied to the first electrode in the first period (for example, period T22 in FIG. 4B) for scanning the first region 411. The change per unit time is smaller than the change per unit time of the voltage applied to the first electrode in the second period of scanning the second region 412 (eg, period T21 and/or period T23 in FIG. 4B) The deflector 115 may be controlled such that Here, the first electrode is any electrode including the electrodes H and V, and is an electrode provided for scanning the electron beam in the first scanning direction.

With this configuration, the movement of the electron beam in the scanning direction is slower in the first period than in the second period. The etching resistance of the resist in the irradiated region is higher than the etching resistance of the resist in the region irradiated with the electron beam during the second period. Thus, even if the etching rate of the region irradiated with the electron beam during the first period is high, the etching resistance of the resist is high. It is possible to reduce the difference in etching amount according to the etching amount.

Here, the second period is divided into a first half period (e.g., period T21 in FIG. 4B) and a second half period (e.g., period T23 in FIG. 4B). T22) is a period sandwiched between the first half of the second period (eg, period T21 in FIG. 4B) and the latter half of the second period (eg, period T23 in FIG. 4B).

In the present embodiment, the area for slowing the scanning speed is a rectangle, but it may be a triangle or a polygon with pentagons or more.

(Modification)
Next, a modified example of this embodiment will be described.

In the present embodiment, the region for slowing the scanning speed is rectangular, but in this modified example, it is substantially circular.

FIG. 4C is a diagram schematically showing an irradiation region 42 of an electron beam, which is a target. The irradiation area 42 is a portion of the substrate on which the layer to be etched is formed. As shown, the irradiation area 42 of the target is substantially circular, and in actuality, for example, the electron beam is irradiated discretely at the positions of the points shown in FIG. 4C. As shown by the polygonal line in FIG. 4C, the electron beam is scanned sequentially from left to right at the same vertical position generally from top to bottom.

As an example, the irradiation region 42 is divided into a first region 421 and a second region 422 having a lower etching rate than the first region 421 . The first region 421 is a region where the etching rate exceeds the threshold and is set substantially in the center of the substrate. Here, as an example, the first region 421 is substantially circular. A substantially circular shape includes a perfect circle and an ellipse, and the line may be a polygonal line as well as a curved line. In the area of the second area 422 located above the first area 421, the vertical position is changed and five lines are scanned in the horizontal direction. After that, the area including the first area 421 is scanned horizontally by 11 lines, for example, by changing the position in the vertical direction. After that, in the area of the second area 422 located below the first area 421, the vertical position is changed and five lines are scanned in the horizontal direction.

As shown in FIG. 4C, in the first region 421, the horizontal dot spacing is narrower than in the outer regions. That is, the moving speed of the electron beam in the horizontal direction within the first region 421 in FIG. 4C is slower than the moving speed of the electron beam in the horizontal direction outside the first region 421 in FIG. 4C.

The processing of the control unit 13 at this time will be described. The controller 13 deflects the electron beam so that the horizontal movement speed of the electron beam within the first region 421 in FIG. 4C is lower than the horizontal movement speed of the electron beam outside the first region 421 in FIG. 4C. device 115; With this configuration, the horizontal movement of the electron beam is slower in the first region 421 in FIG. 4C than in the second region 422 in FIG. , the etch resistance of the resist is higher in the horizontal movement of the electron beam in the first region 421 of FIG. 4C than in the second region 422 of FIG. 4C. As a result, even if the etching rate of the first region 421 in FIG. 4C is higher than that of the second region 422, the etching resistance of the resist is higher than that of the second region 422, so that the amount etched by plasma etching can be reduced. It is possible to reduce the difference in the etching amount according to the distribution of the etching rate.

FIG. 4D is a diagram schematically showing voltages Vh(t) and Vv(t) respectively applied to the electrodes H and V of the deflector 115 from point 4P1 to point 4P2 in the irradiation area 42 of FIG. 4C. be. Similarly, FIG. 4E schematically shows voltages Vh(t) and Vv(t) applied to electrodes H and V of deflector 115 from point 4P2 to point 4P3 in irradiation region 42 of FIG. 4C. FIG. 4 is a diagram showing; 4D and 4E schematically show the relationship between time t and voltages Vh(t) and Vv(t) applied to electrodes H and V, respectively.

Voltage Vv(t) is set to a certain value at a certain time, and is set to a larger value by the difference voltage ΔV2 after a unit time Δt. After that, the voltage Vv(t) remains the same value for a predetermined period T11, and is set to a value larger by the difference voltage ΔV2 after the period T11 has elapsed. Next, the voltage Vv(t) has the same value for a predetermined period T12 (>T11), and is set to a value larger by the difference voltage ΔV2 after the lapse of this period T12. Next, the voltage Vv(t) has the same value for a predetermined period T13 (>T12), and is set to a value larger by the difference voltage ΔV2 after the lapse of this period T13. Next, the voltage Vv(t) has the same value for a predetermined period T14 (>T13), and is set to a value larger by the difference voltage ΔV2 after the lapse of this period T14. The voltage Vv(t) corresponds to the vertical position (line number) in the irradiation area 42, and more specifically, the larger the value of the voltage Vv(t), the closer to the lower end in the vertical direction. Therefore, when such a voltage Vv(t) is applied to the electrode V, the position of the electron beam in the vertical direction changes.

Meanwhile, voltage Vh(t) varies linearly in corresponding periods T11, T12, T13, and T14, respectively. More specifically, voltage Vh(t) linearly increases with a first slope in periods T11, T12, T13, and T14. The voltage Vh(t) corresponds to the horizontal position (number of dots) in the irradiation area 42. More specifically, the larger the value of the voltage Vh(t), the closer to the right end in the horizontal direction. Therefore, by applying such a voltage Vh(t) to the electrode H, the irradiation position of the electron beam shifts in the vertical direction.

After that, when the voltage Vv(t) is set to a value that is further increased by the difference voltage ΔV2, it remains the same value for a predetermined period T15 (>T14), and is set to a value that is increased by the difference voltage ΔV2 after this period T15 has elapsed. be.

In the meantime, voltage Vh(t) changes in a polygonal line shape in period T15. More specifically, the voltage Vh(t) linearly increases with a first slope in the first half period T151, linearly increases with a second slope smaller than the first slope in the middle period T152, and increases linearly with a second slope in the second half period T152. increases linearly with the same first slope as in the first half period T151 in period T153. That is, the change in voltage Vh(t) per unit time in period T152 (that is, the slope of voltage Vh(t) in FIG. 4D) is the change in voltage Vh(t) per unit time in periods T151 and T153 (that is, slope of voltage Vh(t) in FIG. 4D).

After that, when the voltage Vv(t) is set to a value greater by the difference voltage ΔV2, it remains the same value for a predetermined period T16 (>T15), and is set to a value greater by the difference voltage ΔV2 after the lapse of this period T16. be.

In the meantime, voltage Vh(t) changes in a polygonal line shape in period T16. More specifically, the voltage Vh(t) linearly increases with a first slope in the first half period T161, linearly increases with a second slope smaller than the first slope in the middle period T162, and increases linearly with a second slope in the second half period T162. increases linearly with the same first slope as in the first half period T161 in period T163. That is, the change in voltage Vh(t) per unit time in period T162 (that is, the slope of voltage Vh(t) in FIG. 4D) is the change in voltage Vh(t) per unit time in periods T161 and T163 (that is, slope of voltage Vh(t) in FIG. 4D).

After that, when the voltage Vv(t) is set to a value that is further increased by the difference voltage ΔV2, it remains the same value for a predetermined period T17 (>T16), and is set to a value that is increased by the difference voltage ΔV2 after the lapse of this period T17. be.

In the meantime, voltage Vh(t) changes in a polygonal line shape in period T17. More specifically, the voltage Vh(t) linearly increases with a first slope in the first half period T171, linearly increases with a second slope smaller than the first slope in the middle period T172, and increases linearly with a second slope in the second half period T172. increases linearly with the same first slope as in the first half period T171 in period T173. That is, the change in voltage Vh(t) per unit time in period T172 (that is, the slope of voltage Vh(t) in FIG. 4D) is the change in voltage Vh(t) per unit time in periods T171 and T173 (that is, slope of voltage Vh(t) in FIG. 4D).

After that, when the voltage Vv(t) is set to a value that is further increased by the difference voltage ΔV2, it remains the same value for a predetermined period T18 (>T17), and is set to a value that is increased by the difference voltage ΔV2 after the lapse of this period T18. be.

In the meantime, voltage Vh(t) changes in a polygonal line shape in period T18. More specifically, the voltage Vh(t) linearly increases with a first slope in the first half period T181, linearly increases with a second slope smaller than the first slope in the middle period T182, and rises linearly with a second slope in the second half period T182. increases linearly with the same first slope as in the first half period T181 in period T183. That is, the change in voltage Vh(t) per unit time in period T182 (that is, the slope of voltage Vh(t) in FIG. 4D) is the change in voltage Vh(t) per unit time in periods T181 and T183 (that is, slope of voltage Vh(t) in FIG. 4D).

After that, when the voltage Vv(t) is set to a value that is further increased by the difference voltage ΔV2, it remains the same value for a predetermined period T19 (>T18), and is set to a value that is increased by the difference voltage ΔV2 after the lapse of this period T19. be. This is repeated three times as an example.

In the meantime, the voltage Vh(t) changes in a polygonal line shape every period T19. More specifically, the voltage Vh(t) linearly increases with a first slope in the first half period T191, linearly increases with a second slope smaller than the first slope in the middle period T192, and increases linearly with a second slope in the second half period T192. increases linearly with the same first slope as in the first half period T191 in period T193. That is, the change in voltage Vh(t) per unit time in period T192 (that is, the slope of voltage Vh(t) in FIG. 4D) is the change in voltage Vh(t) per unit time in periods T191 and T193 (that is, slope of voltage Vh(t) in FIG. 4D).

After that, when the voltage Vv(t) is set to a value greater by the difference voltage ΔV2, it remains the same value for a predetermined period T18, and is set to a value greater by the difference voltage ΔV2 after the lapse of this period T18.

In the meantime, voltage Vh(t) changes in a polygonal line shape in period T18. More specifically, the voltage Vh(t) linearly increases with a first slope in the first half period T181, linearly increases with a second slope smaller than the first slope in the middle period T182, and rises linearly with a second slope in the second half period T182. increases linearly with the same first slope as in the first half period T181 in period T183. That is, the change in voltage Vh(t) per unit time in period T182 (that is, the slope of voltage Vh(t) in FIG. 4D) is the change in voltage Vh(t) per unit time in periods T181 and T183 (that is, slope of voltage Vh(t) in FIG. 4D).

After that, when the voltage Vv(t) is set to a value greater by the differential voltage ΔV2, it remains the same value for a predetermined period T17, and is set to a value greater by the differential voltage ΔV2 after the lapse of this period T17.

In the meantime, voltage Vh(t) changes in a polygonal line shape in period T17. More specifically, the voltage Vh(t) linearly increases with a first slope in the first half period T171, linearly increases with a second slope smaller than the first slope in the middle period T172, and increases linearly with a second slope in the second half period T172. increases linearly with the same first slope as in the first half period T171 in period T173. That is, the change in voltage Vh(t) per unit time in period T172 (that is, the slope of voltage Vh(t) in FIG. 4D) is the change in voltage Vh(t) per unit time in periods T171 and T173 (that is, slope of voltage Vh(t) in FIG. 4D).

After that, when the voltage Vv(t) is set to a value greater by the difference voltage ΔV2, it remains the same value for a predetermined period T16, and is set to a value greater by the difference voltage ΔV2 after the lapse of this period T16.

In the meantime, voltage Vh(t) changes in a polygonal line shape in period T16. More specifically, the voltage Vh(t) linearly increases with a first slope in the first half period T161, linearly increases with a second slope smaller than the first slope in the middle period T162, and increases linearly with a second slope in the second half period T162. increases linearly with the same first slope as in the first half period T161 in period T163. That is, the change in voltage Vh(t) per unit time in period T162 (that is, the slope of voltage Vh(t) in FIG. 4D) is the change in voltage Vh(t) per unit time in periods T161 and T163 (that is, slope of voltage Vh(t) in FIG. 4D).

After that, when the voltage Vv(t) is set to a value greater by the difference voltage ΔV2, it remains the same value for a predetermined period T16, and is set to a value greater by the difference voltage ΔV2 after the lapse of this period T16.

In the meantime, voltage Vh(t) changes in a polygonal line shape in period T15. More specifically, the voltage Vh(t) linearly increases with a first slope in the first half period T151, linearly increases with a second slope smaller than the first slope in the middle period T152, and increases linearly with a second slope in the second half period T152. increases linearly with the same first slope as in the first half period T151 in period T153. That is, the change in voltage Vh(t) per unit time in period T152 (that is, the slope of voltage Vh(t) in FIG. 4D) is the change in voltage Vh(t) per unit time in periods T151 and T153 (that is, slope of voltage Vh(t) in FIG. 4D).

After that, the voltage Vv(t) remains the same value for a predetermined period T14, and is set to a value larger by the difference voltage ΔV2 after the period T14 has elapsed. Next, the voltage Vv(t) has the same value for a predetermined period T13, and is set to a value larger by the difference voltage ΔV2 after the lapse of this period T13. Next, the voltage Vv(t) has the same value for a predetermined period T12, and is set to a value larger by the difference voltage ΔV2 after the lapse of this period T12. Next, the voltage Vv(t) has the same value for a predetermined period T11, and is set to a value larger by the difference voltage ΔV2 after the lapse of this period T11.
Meanwhile, voltage Vh(t) varies linearly in corresponding periods T11, T12, T13, and T14, respectively. More specifically, voltage Vh(t) linearly increases with a first slope in periods T11, T12, T13, and T14.

Specifically, in the present embodiment, the control unit 13 controls the change per unit time of the voltage Vh(t) in the period T152 of FIG. The deflector 115 is controlled so as to be less than the change in perimeter. With this configuration, in the period T152 of FIG. 4D, the horizontal movement of the electron beam is slower than in the periods T151 and T153 of FIG. 4D. , T151 and T153 in FIG. 4D. As a result, even if the etching rate of the region irradiated with the electron beam in the period T152 of FIG. 4D is high, the etching resistance of the resist is high. It is possible to reduce the difference in the etching amount according to .

Similarly, the control unit 13 controls the change per unit time of the voltage Vh(t) in the period T162 of FIG. 4D to be smaller than the change per unit time of the voltage Vh(t) in the periods T161 and T163 of FIG. 4D. Also, the deflector 115 is controlled. With this configuration, in the period T162 of FIG. 4D, the horizontal movement of the electron beam is slower than in the periods T161 and T163 of FIG. 4D. , T161 and T163 in FIG. 4D. As a result, even if the etching rate of the region irradiated with the electron beam in the period T162 of FIG. 4D is high, the etching resistance of the resist is high. It is possible to reduce the difference in the etching amount according to .

Note that a program for executing each process of the control unit according to the present embodiment and modifications is recorded on a computer-readable recording medium, the program recorded on the recording medium is read by a computer, and the processor executes By doing so, the above-described various processes related to the control unit according to the present embodiment and the modification may be performed.
In this embodiment and the modified example, the deflector 115 is explained as an electrostatic deflector as an example, but the deflector 115 is not limited to this, and may be an electromagnetic deflector. A current is applied to each of the
Moreover, the area where the electron beam dose is varied is not limited to the rectangular or circular central area, and the shape of the area does not matter, the position of the area does not matter, and the area can be applied not only in one place but also in a plurality of places. may exist. If there are multiple regions with different electron beam irradiation doses, the size of each region does not matter, and the electron beam irradiation dose may differ for each region, and whether the electron beam irradiation dose is high or low There are not only two types of

The electron beam generator can be applied not only to the electron beam irradiation device but also to the exposure device and the inspection device.

[Description of symbols]
41 irradiation region 411 first region 412 second region (fourth embodiment)
[Technical field]
The present embodiment relates to an electron beam irradiation apparatus, an electron beam position detection system, an electron beam position detection method, and a program.

[Background technology]
In an electron beam irradiation apparatus, in order to calibrate the irradiation area of the electron beam, a position in a plane substantially perpendicular to the traveling direction of the electron beam (hereinafter referred to as beam position) is detected. .

[Problems to be solved by the present embodiment]
However, there is a problem that a micro channel plate (MCP) that can directly observe the beam position is expensive. A method of arranging silicon photodiodes for each predetermined area is also conceivable, but there is a problem of high cost. On the other hand, fluorescent screens that can detect the beam position are inexpensive, but have the problem of possible particle contamination within the column.

Therefore, an object of the present embodiment is to provide an electron beam irradiation apparatus, an electron beam position detection system, an electron beam position detection method, and a program that can reduce costs and reduce contamination when detecting the beam position. is.

[Means to solve the problem]
<Aspect 1>
a deflector for deflecting the electron beam;
a controller that controls the deflector to scan the electron beam;
a plate having a unique spatial arrangement of a plurality of through holes for each preset region;
a trap that traps electrons in the electron beam that have passed through the through hole;
an ammeter that measures the current generated by the electrons captured by the trap;
with
The control unit uses the distribution of current positions measured by the ammeter when the electron beam scans each region of the plate, and uses the distribution of current positions in a plane substantially perpendicular to the traveling direction of the electron beam. an electron beam irradiation device for detecting the position of the electron beam in the

With this configuration, the spatial distribution of the positions (spots) where the current is measured becomes unique for each region, so it is possible to determine which region the electron beam is passing through. In addition, since the plate, the trap and the ammeter are used for detection, the cost for detecting the beam position can be suppressed. Furthermore, since dust is not generated in the electron beam irradiation device, contamination can be reduced. Furthermore, since the plate is hard to break, the beam position can be stably detected for a long period of time.

<Aspect 2>
The electron beam irradiation device according to aspect 1, wherein the through hole is smaller than the electron beam diameter.

With this configuration, the position (spot) where the current is measured has a diameter smaller than that of the electron beam, and the spatial distribution of this spot is unique for each region, so it is possible to determine which region the electron beam is passing through. can.

<Aspect 3>
the plate is provided with a second through-hole different from the plurality of through-holes in each of the regions and having substantially the same diameter as the electron beam diameter,
Based on the measured current, the controller controls the deflector so as to align the electron beam with one of the second through-holes in a plane substantially perpendicular to the traveling direction of the electron beam. The electron beam irradiation device according to aspect 1 or 2.

With this configuration, the horizontal position of the electron beam can be aligned with the position of the second through hole.

<Aspect 4>
The electron beam irradiation device according to aspect 3, wherein the second through-hole is arranged substantially in the center of the corresponding region.
With this configuration, the horizontal position of the electron beam can be aligned with the substantially central position of the corresponding area.

<Aspect 5>
The electron beam irradiation device according to any one of aspects 1 to 4, wherein the plate further has a third through hole having a diameter larger than the diameter of the electron beam.

With this configuration, when the electron beam passes through approximately the middle of the third through-hole, the electron beam passes through and all the electron beams reach the trap. can be measured.

<Aspect 6>
The electron beam irradiation device according to aspect 5, wherein the third through-hole is arranged substantially in the center of the plate.
With this configuration, it is possible to reliably measure the amount of current irradiated by the electron beam at one time.

<Aspect 7>
7. The electron beam irradiation device according to any one of modes 1 to 6, wherein the plate further has a fourth through hole having a diameter smaller than that of the electron beam.

With this configuration, the spatial distribution of the electron density of the electron beam can be measured from the amount of electrons captured by the trap, that is, the current value of the ammeter when the electron beam moves across the fourth through-hole. can be done.

<Aspect 8>
A metal member provided with an opening is further provided between the plate and the trap,
7. The electron beam irradiation device according to any one of modes 1 to 6, wherein a negative voltage is applied to the metal member.

With this configuration, the metal member is negatively charged, so secondary electrons that have bounced off the trap are further reflected by the metal member. Therefore, this secondary electron is also captured by the trap. This can prevent the secondary electrons from jumping out.

<Aspect 9>
a plate having a unique spatial arrangement of a plurality of through holes for each preset region;
a trap that traps electrons in the electron beam that have passed through the through hole;
an ammeter that measures the current generated by the electrons captured by the trap;
Using the current position distribution measured by the ammeter when the electron beam scans each region of the plate, the electron beam in a plane substantially perpendicular to the traveling direction of the electron beam. a control unit that detects a position;
An electron beam position detection system comprising:

<Aspect 10>
When the trap scans the electron beam for each area of the plate in which the spatial arrangement of the plurality of through holes is unique for each preset area, the electrons that have passed through the through holes in the electron beam are captured. process and
measuring the current due to the electrons captured by the trap with an ammeter;
a step of detecting the position of the electron beam in a plane substantially perpendicular to the traveling direction of the electron beam, using the current position distribution measured by the ammeter by the control unit;
An electron beam position detection method comprising:

<Aspect 11>
A plate having a unique spatial distribution of through-holes, a trap for trapping electrons in an electron beam that have passed through the through-holes, and a current generated by the electrons trapped by the trap is measured for each preset region. A program for execution by a computer of an electron beam position detection system comprising an ammeter,
Using the current position distribution measured by the ammeter when the electron beam scans each region of the plate, the electron beam in a plane substantially perpendicular to the traveling direction of the electron beam. A program having a step of detecting a position.

[Effect of this embodiment]
According to the electron beam irradiation apparatus according to this embodiment, since the spatial distribution of the positions (spots) where the current is measured is specific for each region, it is possible to determine which region the electron beam passes through. . In addition, since the plate, the trap and the ammeter are used for detection, the cost for detecting the beam position can be suppressed. Furthermore, since dust is not generated in the electron beam irradiation device, contamination can be reduced. Furthermore, since the plate is hard to break, the beam position can be stably detected for a long period of time.

[Brief description of the drawing]
[FIG. 5A] A diagram showing a schematic configuration of an electron beam position detection system 500 according to the present embodiment.
[FIG. 5B] A top view of the measurement unit 127 according to the present embodiment.
[FIG. 5C] A top view of the measurement unit 127 according to the present embodiment when the plate 52 is removed.
[FIG. 5D] It is a schematic cross-sectional view showing the AA cross section in FIG. 5B.
[FIG. 5E] A diagram showing an example of the arrangement of through holes in the plate 52. [FIG.
FIG. 5F is a flow chart showing an example of processing for aligning the position of the electron beam with the center of the upper right region of the plate 52;

[Mode for carrying out the present embodiment]

In this embodiment, a dedicated plate 52 is used to detect the position of the electron beam. In addition, the plate 52 is used to automatically adjust the irradiation position of the electron beam before the specimen (sample) is introduced.

FIG. 5A is a diagram showing a schematic configuration of an electron beam position detection system 500 according to this embodiment. The electron beam position detection system 500 detects the position of the electron beam. As shown in FIG. 5A, the electron beam position detection system 500 includes a plate 52, a trap 54 arranged below the plate 52, an ammeter 55 connected to the trap 54, and a controller 13. . The plate 52 is provided with a plurality of through holes through which the electron beams EB emitted from the electron beam generator 112 pass. Ammeter 55 is connected to general control section 131 in control section 13 . The electron beam control section 132 controls the voltage applied to the electrode 5115 provided in the deflector 151 based on the control command from the general control section 131 .

FIG. 5B is a top view of the measurement unit 127 according to this embodiment. As shown in FIG. 5B, the measurement unit 127 includes a housing 51 and a plate 52 provided on the housing 51. As shown in FIG. As shown in FIG. 5B, the plate 52 is provided with a plurality of through holes.

FIG. 5C is a top view of the measurement unit 127 according to this embodiment when the plate 52 is removed. As shown in FIG. 5C, the measurement unit 127 further includes a grid-shaped metal member (also referred to as a mesh) 53 and a trap 54 that traps electrons.

FIG. 5D is a schematic cross-sectional view showing the AA cross section in FIG. 5B. As shown in FIG. 5D, metal member 53 is provided between plate 52 and trap 54 and is fixed inside housing 51 . Also, the metal member 53 is connected to the cathode of the power supply 56 and a negative voltage is applied to the metal member 53 . As a result, the metal member 53 is negatively charged, and the secondary electrons that bounce off the trap 54 as indicated by the arrow 5A1 are further reflected by the metal member 53 as indicated by the arrow 5A2. Therefore, this secondary electron is also captured by the trap 54 . This can prevent the secondary electrons from jumping out of the housing 51 .

The trap 54 traps electrons that have passed through the through-hole in the electron beam generated by the electron beam generator 112 . Here, the trap 54 according to this embodiment is a Faraday cup.

The ammeter 55 detects the current due to the electrons captured by the trap 54 . A current value signal indicating the current value measured by the ammeter 55 is transmitted to the control unit 13 .

FIG. 5E is a diagram showing an example of the arrangement of through holes in the plate 52. FIG. As shown in FIG. 5E, in this embodiment, as an example, four through holes with different diameters are provided as through holes. In this embodiment, as an example, the through holes are not arranged to interfere with each other.

As shown in FIG. 5E, the plate 52 has a plurality of regions. Here, as an example, 25 regions (regions surrounded by dashed lines) 5R1 to 5R25 are set in advance on the plate 52, and the spatial distribution of through holes (for example, The spatial arrangement of the through-holes, or the shape of the through-holes, or a combination thereof) is unique. The diameter of the first through-hole is, for example, about 2/3 of the beam diameter of the electron beam. Since the spatial distribution of the through-holes is unique for each preset region on the plate 52, the current spatial distribution is also unique for each region. Using this fact, the control unit 13 detects the position of the electron beam in the horizontal direction using the distribution of the position of the current measured by the ammeter 55 when the electron beam scans each region of the plate 52. do. As a result, the spatial distribution of the positions (spots) where the current is measured becomes unique for each region, so it is possible to determine which region the electron beam is passing through.

Here, as an example, as one of the through holes, a plurality of (here, three as an example) first through holes (for example, 5M51, 5M52, and 5M53) smaller than the electron beam diameter are provided. The spatial arrangement of the first through holes in the plate 52 is unique for each region. The diameter of the first through-hole is, for example, about 2/3 of the beam diameter of the electron beam. Since the spatial arrangement of the first through-holes is unique for each preset region on the plate 52, the current spatial distribution is also unique for each region. It is also assumed that the position of the entire irradiation range of the electron beam is not shifted. Using this fact, the control unit 13 uses the current spatial distribution obtained by the current measured by the ammeter 55 when the electron beam is scanned for each region of the plate 52, and to detect the position of the electron beam (beam position) in a substantially vertical plane. As a result, the position (spot) where the current is measured has a diameter smaller than that of the electron beam, and the spatial distribution of this spot is unique to each region, so it is possible to determine which region the electron beam is passing through. .

The plate 52 is provided with second through holes 5L1 to 5L25 having substantially the same diameter as the electron beam in each of the above regions. When the position of the electron beam in a plane substantially perpendicular to the traveling direction of the electron beam is aligned with the position of one second through-hole, the measured current is maximized. Using this fact, the controller 13 controls the deflector 151 to align the position of the electron beam with the second through-hole in a plane substantially perpendicular to the direction of travel of the electron beam, based on the measured current. to control. Thereby, the horizontal position of the electron beam can be aligned with the position of the second through hole. Here, the second through holes 5L1 to 5L25 are arranged substantially in the center of the corresponding regions. Thereby, the horizontal position of the electron beam can be aligned with the substantially central position of the corresponding area. In the center of each area, the second through holes 5L1 to 5L25 are connected to other surrounding first through holes (eg, 5M51, It is preferably 1.5 times larger than the diameter of 5M52, 5M53). Specific processing will be described later with the flowchart of FIG. 5F.

The plate 52 is further provided with a third through hole 5LL having a diameter larger than the electron beam diameter. As a result, when the electron beam passes through approximately the center of the third through-hole 5LL, the electron beam passes through and all the electron beams reach the trap 54, so the ammeter 55 is irradiated with the electron beam at once. The amount of current can be measured. The third through hole 5LL is arranged substantially in the center of the plate 52 (within the region 5R13). This makes it possible to reliably measure the amount of current irradiated by the electron beam at one time.

The plate 52 is further provided with nine fourth through-holes (for example, fourth through-holes 5S5) having a smaller diameter than the electron beam. These fourth through-holes are for beam profile measurements of the electron beam. As a result, when the electron beam moves across the fourth through holes 5S1 to 5S25, the amount of electrons captured by the trap 54, that is, the current value of the ammeter 55, the spatial distribution of the electron density of the electron beam can be measured. As an example in this embodiment, the fourth through-hole (for example, the fourth through-hole 5S5) has a smaller diameter than the first through-holes (for example, 5M51, 5M52, 5M53).

Next, referring to FIG. 5F, the process of aligning the horizontal position of the electron beam to the approximate center position of the corresponding area will be described. FIG. 5F is a flow chart showing an example of processing for aligning the position of the electron beam with the center of the upper right region of the plate 52 . In this flowchart, the diameter of the second through-hole 5L5 provided in the upper right region 5R5 of the plate 52 is substantially the same as the diameter of the electron beam, and the electron beam is directed through the second through-hole 5L5. Align to position. Voltages applied to the electrodes H and V of the deflector 115 are referred to as Vh and Vv (hereinafter referred to as deflection voltages). A deflection voltage Vh is a voltage for scanning in the horizontal direction, and a deflection voltage Vv is a voltage for scanning in the vertical direction.

(Step S501) The deflection voltages Vh and Vv of the electron beam that can scan the upper right region 5R5 of the plate 52 are calculated and set in advance from the position and the electron energy. Here, as an example, the deflection voltages Vh and Vv are both 1 to 3V, and both have a variable amount of 2V.
First, the control unit 13 causes the upper right deflection range corresponding to the upper right region 5R5 of the plate 52 to be horizontally scanned at predetermined first horizontal intervals at predetermined first vertical intervals. device 115;

(Step S502) Next, the controller 13 detects the deflection voltages when the current detected by the ammeter 55 is maximum as deflection voltages Vhmax and Vvmax. At these deflection voltages Vhmax and Vvmax, the electron beam passes through substantially the center of the upper right region 5R5 of the plate 52. FIG. The control unit 13 then stores the deflection voltages Vhmax and Vvmax when the detected current is maximum in a memory (not shown). Here, for example, it is assumed that the deflection voltages Vh and Vv are 2.1 V and 2.2 V when the detection current is maximum. As a result, the center of the upper right region 5R5 of the plate 52 can be detected with rough positional accuracy.

(Step S503) Next, the control unit 13 sets the deflection variable amount of the deflection voltage Vh and the deflection variable amount of the deflection voltage Vv to, for example, half. Here, for example, if the deflection variable amount is set to 1 V, which is half of 2 V, the deflection voltage Vh takes a value of 1.6 to 2.6 V around 2.1 V because the deflection variable amount is 1 V, and the deflection voltage Vv takes a value of 1.7 to 2.7 V because the deflection variable amount is 1 V with 2.2 V as the center.

(Step S504) Next, the control unit 13 starts scanning under the condition that the deflection variable amount of the deflection voltage Vh and the deflection variable amount of the deflection voltage Vv are half of those in step S501, centering on the deflection voltages Vhmax and Vvmax. It controls the deflector 115 as follows. In doing so, for example, every second vertical interval smaller than the first vertical interval may be scanned at a second horizontal interval smaller than the first horizontal interval. As a result, the center of the upper right region 5R5 of the plate 52 can be detected with higher positional accuracy than in step S502.

(Step S505) Every time the deflection voltages Vh and Vv are changed, the control unit 13 determines whether or not the current detected by the ammeter 55 is approximately the same as a preset current value. Here, "substantially the same" means that the detected current is within a predetermined range based on the set current value. Here, the set current value is the charge amount per unit time of the electron beam generated by the electron beam generator 112 .

(Step S506) If the detected current is not substantially the same as the preset current value in step S505, the controller 13 changes the deflection voltages Vh and Vv to the next deflection voltages, and the process returns to step S505.

(Step S507) On the other hand, when the detected current is substantially equal to the preset current value in step S505, it is estimated that the electron beam passes through the second through hole 5L5 in the upper right region 5R5 of the plate 52. Therefore, the control unit 13 stops changing the deflection voltages Vh and Vv. Since the second through hole 5L5 is in the center of the upper right region 5R5 of the plate 52, the electron beam passes through the center of the upper right region 5R5 of the plate 52 at this time. In this manner, the deflection voltages Vhmax and Vvmax are detected at the center of the upper right region 5R5 of the plate 52 in the first scan, and the electron beam is directed to the center of the upper right region 5R5 of the plate 52 in the next scan. can be aligned. With this, the processing of this flowchart ends.

As described above, the electron beam irradiation apparatus according to the present embodiment includes the deflector 115 that deflects the electron beam, the controller 13 that controls the deflector 115 to scan the electron beam, and a plurality of electron beams for each preset region. A plate 52 having a unique spatial arrangement of through-holes, a trap 54 for trapping electrons passing through the through-holes in the electron beam generated by the electron beam generator 112, and a current generated by the electrons trapped by the trap 54. and an ammeter 55 for measuring The control unit 13 uses the current position distribution measured by the ammeter 55 when the electron beam scans each region of the plate 52 to detect the electrons in a plane substantially perpendicular to the traveling direction of the electron beam. Detect the position of the beam.

With this configuration, the spatial distribution of the positions (spots) where the current is measured becomes unique for each region, so it is possible to determine which region the electron beam is passing through. Moreover, since the plate 52, the trap 54, and the ammeter 55 are used for detection, the cost for detecting the beam position can be suppressed. Furthermore, since dust is not generated in the electron beam irradiation device, contamination can be reduced. Furthermore, since the plate 52 is hard to break, the beam position can be stably detected for a long period of time.

In addition, although the shape of the 1st through-hole which concerns on this embodiment was a substantially circle, it is not restricted to this. The shape of the first through-hole may be different for each region, such as a different number shape for each region. The shape of the through-hole may be substantially circular, square, triangular, or any other polygonal shape.

Note that a program for executing each process of the control unit according to the present embodiment and modifications is recorded on a computer-readable recording medium, the program recorded on the recording medium is read by a computer, and the processor executes By doing so, the above-described various processes related to the control unit according to the present embodiment and the modification may be performed.

In the present embodiment, the metal member 53 has a lattice shape, but it is not limited to this, and the metal member 53 may have regular hexagonal openings in a honeycomb shape. should be provided.

The electron beam generator can be applied not only to the electron beam irradiation device but also to the exposure device and the inspection device.

[Description of symbols]
13 Control Part 51 Case 52 Plate 53 Metal Member 54 Catcher 55 Ammeter 56 Power Supply 127 Measurement Unit 131 Overall Control Part 132 Electron Beam Control Part 151 Deflector 500 Electron Beam Position Detection System 5115 Electrode

(Fifth embodiment)
[Technical field]
This embodiment relates to an electron beam irradiation apparatus.

[Background technology]
The present applicant has already proposed an electron beam irradiation apparatus that irradiates a sample with an electron beam to perform surface treatment (see Patent Document 1). This electron beam irradiation apparatus is provided with a lift mechanism for raising and lowering the stage, and an application pin is arranged above the sample on the stage. By raising the stage by the lift mechanism and bringing the application pin into contact with the surface of the sample on the stage, the potential of the surface of the sample is connected to the ground potential and stabilized.

However, such an electron beam irradiation apparatus has a problem that dust and outgas from the lift mechanism are emitted into the vacuum chamber, contaminating the atmosphere inside the vacuum chamber.

[Problems to be solved by the present embodiment]

Provided is an electron beam irradiation apparatus capable of preventing the atmosphere in a vacuum chamber from being contaminated by dust and outgassing from a lift mechanism when an application pin is pressed against the surface of a sample on a sample stage to conduct.

[Means to solve the problem]
<Aspect 1>
a sample table for holding the sample in the vacuum chamber;
an electron source for generating an electron beam to irradiate the sample on the sample table;
a potential control unit that controls the potential of the sample on the sample table;
with
The potential control unit is
an application pin arranged above the sample on the sample stage;
an application pin lift mechanism arranged outside the vacuum chamber and capable of vertically moving the application pin to press it against the surface of the sample on the sample table.
<Aspect 2>
The electron beam irradiation device according to aspect 1, wherein the application pin has a spring pin.
<Aspect 3>
The application pin is provided at an upper end portion of a vertically extending support member,
the lower end of the support member penetrates the bottom of the vacuum chamber and protrudes to the outside;
A space between the lower end of the support member and the bottom of the vacuum chamber is airtightly covered by an expandable bellows,
The electron beam irradiation device according to aspect 1 or 2, wherein the application pin lift mechanism is connected to the lower end of the support member.
<Aspect 4>
The support member has a cylindrical shape,
The electronic device according to aspect 3, wherein the conducting wire electrically connected to the applying pin passes through the inside of the supporting member and is led out to the outside through a feedthrough provided at the lower end of the supporting member. Beam irradiation device.
<Aspect 5>
The electron beam irradiation device according to any one of aspects 1 to 4, wherein the application pin is connected to ground potential.
<Aspect 6>
The application pin has a pair of pin members,
6. The potential control unit according to any one of aspects 1 to 5, further comprising detecting means for applying a voltage to one of the pin members and detecting conduction between the one pin member and the other pin member. Electron beam irradiation device.
<Aspect 7>
The electron beam irradiation device according to aspect 6, wherein the potential control section causes the detection means to reapply the voltage to the one pin member when the detection means does not detect the conduction. <Aspect 8>
The electron beam irradiation apparatus according to mode 6, wherein the potential control section restarts the pressing of the application pin against the surface of the sample by the application pin lift mechanism when the detection means does not detect the conduction.

[Effect of this embodiment]
In the electron beam irradiation apparatus, it is possible to prevent the atmosphere in the vacuum chamber from being contaminated by dust or outgassing from the moving mechanism when the application pin is pressed against the surface of the sample on the sample stage to conduct.

[Brief description of the drawing]
[FIG. 6A] A schematic diagram showing an enlarged configuration of an application pin of the electron beam irradiation device.
[FIG. 6B] A schematic diagram showing the wiring of the potential control section.
[FIG. 6C] A flow chart showing an example of the operation of the electron beam irradiation device.
[FIG. 6D] A plan view showing a configuration related to teaching of the robot hand.
[FIG. 6E] A view showing a cross section along line AA of the configuration shown in FIG. 6D.
[Fig. 6F] A plan view of the teaching plate.

[Mode for carrying out the present embodiment]
(Potential control of sample)
FIG. 6A is a schematic diagram showing an enlarged configuration of the application pin 125 of the electron beam irradiation apparatus 10 according to the present embodiment.

As shown in FIG. 6A, the electron beam irradiation apparatus 10 includes a sample table 124 that holds a sample W in a vacuum chamber 121, and an electron source 112 that generates an electron beam to irradiate the sample W on the sample table 124 (see FIG. 6A). 1A) and a potential control unit 620 that controls the potential of the sample W on the sample table 124 .

As described above, in the electron beam irradiation apparatus 10, the irradiation energy is determined according to the difference between the potential (eg, −0.2 kV to −5 kV) of the electron source (electron beam generator) 112 and the potential of the sample W. If the potential of the sample W is floating, the irradiation energy becomes unstable. Therefore, the potential control unit 620 is used to control the potential of the sample W (for example, connect it to the ground potential).

As shown in FIG. 6A, the potential control unit 620 includes an application pin 125 arranged above the sample W on the sample table 124, and is arranged outside the vacuum chamber 121 to move the application pin 125 up and down to control the sample table. and an application pin lift mechanism 630 that can be pressed against the surface of the sample W on 124 .

Of these, the application pin 125 preferably has a spring pin. When an insulating film is formed on the surface of the sample W, when the application pin lift mechanism 630 presses the spring pin against the surface of the sample W, the spring pin is rubbed against the surface of the sample W, so that a part of the insulating film is lifted by the spring pin. be scraped off. As a result, the spring pin can penetrate through the insulating film on the surface of the sample W and reliably conduct with the conductive portion of the sample W. FIG.

In the illustrated example, the application pin 125 is provided at the upper end of a vertically extending support member 622 . The lower end of the support member 622 penetrates the bottom of the vacuum chamber 121 and protrudes to the outside.

A stretchable bellows 623 is arranged coaxially with the support member 622 around the lower end of the support member 622 , and a stretchable bellows 623 is provided between the lower end of the support member 622 and the bottom of the vacuum chamber 121 . 623 is hermetically covered.

The application pin lift mechanism 630 is connected to the lower end of the support member 622 outside the vacuum chamber 121 .

More specifically, as shown in FIG. 6A, the application pin lift mechanism 630 includes a ball screw 633, a motor 635 connected to the ball screw 633 via a coupling 634, and a mounting member 631 capable of moving up and down along the ball screw 633. , and a linear guide 632 for guiding the mounting member 631 , the mounting member 631 being attached to the lower end of the support member 622 .

When the ball screw 633 is rotated by the output of the motor 635 , the mounting member 631 is vertically moved along the ball screw 633 together with the support member 622 and the application pin 125 .

When the application pin lift mechanism 630 operates, dust and outgas are generated from the application pin lift mechanism 630 . However, since the space between the lower end of the support member 622 and the bottom of the vacuum chamber 121 is air-tightly covered by the expandable bellows 623, dust and outgassing from the application pin lift mechanism 630 are blocked by the bellows 623. There is no intrusion into the interior through the through hole 621 at the bottom of the vacuum chamber 121 .

In the illustrated example, the apply pin 125 is connected to ground potential. More specifically, the support member 622 has a cylindrical shape, and a lead wire 625 electrically connected to the application pin 125 passes through the inner side of the support member 622 and is provided at the lower end of the support member 622 . It is pulled out to the outside through a feedthrough 624 and connected to the ground potential.

FIG. 6B is a schematic diagram showing the wiring of the potential controller 620. As shown in FIG.

As shown in FIG. 6B, the application pin 125 has a pair of pin members 671,672.

Potential control unit 620 applies a voltage (for example, positive voltage) to one pin member 671 that is different from that of the other pin member 672, and detects conduction between one pin member 671 and the other pin member 672. It further has a detection means 673 for detecting.

A relay 674 is arranged between one pin member 671 and the detection means 673 . By switching the relay 674 , one pin member 671 is connected to either the ground potential (0 V) or the output voltage (positive voltage) of the detection means 673 .

When the application pin 125 is pressed against the surface of the sample W on the sample stage 124 by detecting the conduction between the one pin member 671 and the other pin member 672 by the detection means 673, the sample W and the application pin 125 are detected. It is possible to easily confirm whether or not there is continuity.

If the detection means 673 does not detect conduction between the sample W and the application pin 125 , the potential control section 620 operates the relay 674 to prevent the detection means 673 from applying voltage to one of the pin members 671 . Configured to start over. According to the verification by the inventors of the present invention, even if the detection means 673 does not detect the conduction between the sample W and the application pin 125 by chance, the voltage application from the detection means 673 to one of the pin members 671 is redone. Thus, there is a possibility that the electrical connection between the sample W and the application pin 125 can be detected.

As a modification, the potential control unit 620 causes the application pin lift mechanism 630 to press the application pin 125 against the surface of the sample W again when the detection means 673 does not detect the conduction between the sample W and the application pin 125 . may be configured to Such an aspect may also make it possible to detect conduction between the sample W and the application pin 125 .

Next, an example of the operation of the electron beam irradiation device 10 will be described with reference to FIG. 6C. FIG. 6C is a flowchart showing the flow of processing when electron beam irradiation of a certain sample W is completed, and then the next sample W is transported and electron beam irradiation is performed.

In the example shown in FIG. 6C, first, the sample W is prepared for transportation. That is, the electron beam irradiation to the sample W whose surface treatment has been completed is stopped (step S601), and the particle catcher 11B (see FIG. 1A) is inserted into the vacuum tube 111 (step S602). This can prevent particles from falling onto the sample W from the later operated gate valve. Then, the gate valve 11A is closed (step S603). Thereby, the inside of the vacuum tube 111 (especially the vicinity of the electron beam generator 112) and the inside of the main chamber 121 are separated. Next, the application pin lift mechanism 630 lifts the application pin 125 to separate the application pin 125 from the surface of the sample W (step S604).

Next, the sample W is transported. That is, the transport gate valve 122 is opened (step S605), the surface-treated sample W is unloaded from the main chamber 121, and the next sample W is loaded into the main chamber 121 (step S606). After that, the transport gate valve 122 is closed (step S607).

Then, the next sample W is irradiated with the electron beam. That is, the application pin lift mechanism 630 lowers the application pin 125, and the application pin 125 contacts the surface of the sample W (step S608).

In the present embodiment, since the application pin lift mechanism 630 is arranged outside the vacuum chamber 121, the atmosphere in the vacuum chamber 121 is prevented from being contaminated by dust and outgassing from the application pin lift mechanism 630. .

Next, the detection means 673 applies a voltage (for example, a positive voltage) to one pin member 671 to detect conduction between one pin member 671 and the other pin member 672 (step S609). Then, the potential control unit 620 determines whether or not the detection means 673 has detected continuity (step S610).

When it is determined that the detection means 673 has not detected the continuity (step S610: YES), the relay 674 is switched, and the voltage is reapplied from the detection means 673 to the pin member 671 on one side. Then, the process is redone from step S610.

On the other hand, if it is determined that the detection means 673 has detected continuity (step S610: YES), it is guaranteed that the surface potential of the sample W is connected to the ground potential. When the evacuation of the main chamber 121 is completed, the gate valve 11A is opened (step S611), and the particle catcher 11B is pulled out from the vacuum tube 111 (step S612). Then, electron beam irradiation to the sample W is started (step S613).

According to the present embodiment as described above, since the application pin lift mechanism 630 for pressing the application pin 125 against the surface of the sample W on the sample table 124 to make it conductive is arranged outside the vacuum chamber 121, application It is possible to prevent the atmosphere in the vacuum chamber 121 from being contaminated by dust and outgas from the pin lift mechanism 630 .

Further, according to the present embodiment, when the application pin 125 is pressed against the surface of the sample W on the sample table 124, the application pin 125 is vertically moved by the application pin lift mechanism 630, and the sample table 124 holding the sample W is moved up and down. Not moved. Therefore, the sample table 124 can stably hold the sample W to be irradiated with the electron beam at a predetermined position.

Further, according to the present embodiment, since the application pin 125 has a spring pin, when an insulating film is formed on the surface of the sample W, the application pin lift mechanism 630 presses the spring pin against the sample surface. At this time, the insulating film on the surface of the sample W is scraped off by the spring pin. As a result, the spring pin can penetrate through the insulating film on the surface of the sample W and reliably conduct with the conductive portion of the sample W. FIG.

Further, according to the present embodiment, the detection means 673 applies a voltage to one pin member 671 of the application pin 125 to detect conduction between the one pin member 671 and the other pin member 672. , when pressing the application pin 125 against the surface of the sample W on the sample table 124, it is possible to easily confirm whether or not the sample W and the application pin 125 are electrically connected.

(Installation of measuring unit)
Returning to FIG. 1A, in this embodiment, the measurement unit 127 that measures the electron beam is immovably installed inside the vacuum chamber 121 .

If the measurement unit 127 is configured to be movable within the vacuum chamber 121, the cable electrically connected to the measurement unit 127 also moves and bends when the measurement unit 127 moves. Dust may be generated by rubbing against surrounding members.

On the other hand, according to the present embodiment, the measuring unit 127 for measuring the electron beam is immovably installed in the vacuum chamber 121, so dust generation accompanying the movement of the measuring unit 127 can be avoided.

(Robot hand teaching method)

Next, a teaching method for the robot hand 641 that conveys the sample W will be described with reference to FIGS. 6D to 6F. FIG. 6D is a plan view showing a configuration related to teaching of the robot hand 641. FIG. FIG. 6E is a diagram showing a cross section along line AA in FIG. 6D. 6F is a plan view of teaching plate 660. FIG.

As shown in FIGS. 6D and 6E, the electron beam irradiation apparatus 10 according to this embodiment further includes a teaching plate 660. As shown in FIG. As a material of the teaching plate 660, for example, a transparent resin is used.

As shown in FIG. 6F, a marking line 661 having the same shape as the robot hand 641 is attached to the surface of the teaching plate 660 . A plurality of (four in the illustrated example) positioning holes 652 are formed in the teaching plate 660 so as to surround the marking line 661 .

On the other hand, the sample table 124 is formed with a plurality of (four in the illustrated example) positioning holes 651 corresponding to the positioning holes 652 of the teaching plate 660 . The positioning holes 651 are arranged inside the area surrounded by the sample support pins 650 that support the sample W. As shown in FIG.

When teaching the robot hand 641 in the electron beam irradiation apparatus 10 having such a configuration, first, instead of the sample W, the teaching plate 660 is placed on the sample stage 124 . Teaching plate 660 is held by the tips of sample support pins 650 protruding from sample table 124 .

Next, as shown in FIG. 6F, positioning pins 653 are commonly inserted into the positioning holes 652 of the teaching plate 660 and the positioning holes 651 of the sample stage 124, respectively. Thereby, the teaching plate 660 is accurately positioned at a predetermined position with respect to the sample stage 124 .

Next, the robot hand 641 is extended from the transfer chamber 640 through the transfer gate valve 122 to the main chamber 121 . The robot hand 641 is then inserted into the space between the sample stage 124 and the teaching plate 660 .

Next, the position of the robot hand 641 is confirmed from above the teaching plate 660 visually or by a detector such as a CCD sensor. Then, the robot hand 641 is taught so that the robot hand 641 is aligned with the marking line 661 of the teaching plate 660 .

According to the teaching method as described above, even an inexperienced engineer can easily teach the robot hand 641 .

The teaching method as described above may be performed in an atmospheric pressure atmosphere or in a vacuum atmosphere. If the teaching is performed in a vacuum atmosphere, it is the same as the case of electron beam irradiation, and teaching can be performed taking into account the influence of distortion of the main chamber 121, which is preferable.

[Description of symbols]
10 electron beam irradiation device 121 vacuum chamber (main chamber)
122 transport gate valve 124 sample table (stage)
125 Application pin 620 Potential control unit 621 Through hole 622 Support member 623 Bellows 624 Feed through 625 Lead wire 630 Application pin lift mechanism 631 Mounting member 632 Linear guide 633 Ball screw 634 Coupling 635 Motor 640 Transfer chamber 641 Robot hand 650 Sample support pin 651 Positioning Positioning hole 652 Positioning hole 653 Positioning pin 660 Teaching plate 661 Marking wire 671 Pin member 672 Pin member 673 Detecting means 674 Relay

(Sixth embodiment)
[Technical field]
This embodiment relates to a connecting device for connecting pipes having different flange sizes.

[Background technology]

FIG. 7A is a schematic diagram showing an example of a conventional connecting pipe 790 that connects pipes with different flange sizes. As shown in FIG. 7A, for example, when connecting the ICF70 standard flange 721 on the column side of the electron beam irradiation device and the ICF114 standard flange 722 on the turbomolecular pump side, the first flange portion 791 of the ICF70 standard and a second flange portion 792 conforming to the ICF114 standard (sometimes referred to as a modified nipple) is used. A first flange portion 791 of the connecting pipe 790 is screwed to the flange 721 on the column side with a first gasket 794 interposed therebetween, and a second flange portion 792 is screwed to the flange 722 on the turbo molecular pump side. 2 gasket 795 is sandwiched and screwed.

By the way, if the piping distance can be shortened, the space can be saved and the exhaust efficiency can be improved. Further, for example, when the pipe extends horizontally, the load bearing capacity of the connecting portion can be increased.

However, in the conventional connecting pipe 790, a cylindrical body portion 793 exists between the first flange portion 791 and the second flange portion 792, and the entire length of the connecting pipe 790 is, for example, 100 mm. In order to shorten the piping distance, it is necessary to shorten the length of the main body portion 793. For example, if the length of the main body portion 793 is shorter than the length of the screw, the length of the screw when screwing the first flange portion 791 can be reduced. The head physically interferes with the second flange portion 792, and the first flange portion 791 cannot be screwed. Therefore, the conventional connecting pipe 790 has a limit in shortening the pipe distance.
[Problems to be solved by the present embodiment]
To provide a connecting tool capable of shortening a pipe distance when connecting pipes having different flange sizes.

[Means to solve the problem]
<Aspect 1>
A connecting device for connecting pipes having different flange sizes,
a first flange member arranged to overlap the flange on the small diameter side;
a second flange member overlappingly arranged between the first flange member and the flange on the large diameter side;
with
The second flange member has a convex portion that enters the inside of the first flange member,
The first flange member is formed with a first fixing hole coaxial with the fixing hole of the flange on the small diameter side,
A coupling tool, wherein the first flange member and the second flange member are each formed with a second fixing hole coaxial with the fixing hole of the large diameter side flange.
<Aspect 2>
A coupling device according to aspect 1, wherein the tip of the protrusion is tapered.
<Aspect 3>
The coupling device according to aspect 1 or 2, wherein the outer diameter of the first flange member and the outer diameter of the second flange member are each equal to the outer diameter of the larger diameter side flange.
<Aspect 4>
A method for connecting pipes having different flange sizes using the connecting device according to any one of aspects 1 to 3,
Arranging the first flange member so as to overlap the flange on the small diameter side,
screwing the first flange member to the flange on the small diameter side by inserting screws in common into the first fixing hole and the fixing hole of the flange on the small diameter side;
inserting a first seal member inside the first flange member;
The second flange member is arranged to overlap the first flange member, and the first seal member is sandwiched between a convex portion entering the inside of the first flange member and the flange on the small diameter side,
placing the large-diameter-side flange over the second flange member while sandwiching the second seal member between the second flange member and the large-diameter-side flange;
Screws are commonly inserted into the second fixing hole of the first flange member, the second fixing hole of the second flange member, and the fixing hole of the flange on the large diameter side, and the first flange member and A method, wherein the second flange member is fastened together with the flange on the large diameter side.
<Aspect 5>
5. The method of aspect 4, wherein the first sealing member and the second sealing member are gaskets or O-rings.
<Aspect 6>
a column;
a turbomolecular pump;
The connecting device according to any one of claims 1 to 3, which connects the column-side flange and the turbo-molecular pump-side flange;
An electron beam irradiation device with

[Effect of this embodiment]
The pipe distance can be shortened when connecting pipes with different flange sizes.

[Brief description of the drawing]
[Fig. 7A] A schematic diagram showing an example of a conventional connecting pipe.
[Fig. 7B] A schematic diagram showing an example of a connecting device according to the present embodiment.
7C is a plan view of the first flange member of the coupling device shown in FIG. 7B; FIG.
[FIG. 7D] A view showing a cross section along line AA of the first flange member shown in FIG. 7C.
7E is a plan view of the second flange member of the coupling device shown in FIG. 7B; FIG.
[FIG. 7F] A view showing a cross section along line BB of the second flange member shown in FIG. 7E.
[FIG. 7G] A flow chart showing an example of a method of connecting pipes having different flange sizes using the connecting device shown in FIG. 7B.

[Mode for carrying out the present embodiment]
FIG. 7B is a schematic diagram illustrating an example of a coupling device 710 according to this embodiment. The connecting device 710 is used to connect pipes having different flange sizes. Specifically, for example, the connecting device 710 includes a small-diameter flange 721 (for example, an ICF70 standard flange) arranged on the column 111 (see FIG. 1A) side of the electron beam irradiation device 10 and a turbomolecular pump 118 side. It is used to connect the large diameter side flange 722 (for example, ICF114 standard flange) arranged in the .

As shown in FIG. 7B , the connecting device 710 is arranged to overlap a first flange member 711 which overlaps the small diameter side flange 721 and which overlaps between the first flange member 711 and the large diameter side flange 722 . and a second flange member 712 .

7C is a plan view of the first flange member 711, and FIG. 7D is a cross-sectional view of the first flange member 711 taken along line AA.

As shown in FIGS. 7C and 7D, the first flange member 711 has a ring-shaped disc shape. The inner diameter of the first flange member 711 is larger than the inner diameter of the flange 721 on the small diameter side. exposed. Also, the outer diameter of the first flange member 711 is equal to the outer diameter of the flange 722 on the large diameter side.

As shown in FIG. 7C, the first flange member 711 has a plurality of (six in the illustrated example) first fixing holes 711a, each having a small diameter so as to correspond to the fixing holes of the flange 721 on the small diameter side. It is formed coaxially with the fixing hole of the side flange 721 . As shown in FIG. 7D, one end of the first fixing hole 711a is provided with a counterbore 711c for accommodating the head of the screw.

Further, as shown in FIG. 7C, the first flange member 711 has a plurality of (six in the illustrated example) second fixing holes 711b corresponding to the fixing holes of the flange 722 on the large diameter side. , is formed coaxially with the fixing hole of the flange 722 on the large diameter side.

7E is a plan view of the second flange member 712, and FIG. 7F is a cross-sectional view of the second flange member 712 taken along line BB.

As shown in FIGS. 7E and 7F , the second flange member 712 has a body portion 712 d having a ring-shaped disk shape and a convex portion 712 a that enters the inside of the first flange member 711 . The convex portion 712a has a cylindrical shape and is provided so as to coaxially extend from the main body portion 712d. Also, the outer diameter of the body portion 712d is equal to the outer diameter of the flange 722 on the large diameter side.

As shown in FIG. 7E, a main body portion 712d of the second flange member 712 has a plurality of (six in the illustrated example) second fixing holes 712b corresponding to the fixing holes of the flange 722 on the large diameter side. It is formed coaxially with the fixing hole of the flange 722 on the large diameter side.

As shown in FIG. 7F, the tip of the protrusion 712a of the second flange member 712 is tapered 712c to facilitate crushing of the first sealing member 714, which will be described later.

Referring now to FIG. 7G, a method of using coupling device 710 will be described. FIG. 7G is a flow chart showing an example of a method for connecting pipes having different flange sizes using the connecting device 710. FIG.

In the example shown in FIG. 7G, first, the first flange member 711 is placed coaxially over the flange 721 on the small diameter side (step S701). Then, the first fixing holes 711a of the first flange member 711 are aligned in the circumferential direction so as to face the fixing holes of the flange 721 on the small diameter side.

Next, screws are commonly inserted into the first fixing hole 711a of the first flange member 711 and the fixing hole of the flange 721 on the small diameter side, and the first flange member 711 is screwed to the flange 721 on the small diameter side. (Step S702). Since a counterbore 711c is formed at the end of the first fixing hole 711a, the head of the screw is accommodated in the counterbore 711c and does not protrude from the first flange member 711 to the outside.

Next, the first seal member 714 is coaxially inserted inside the first flange member 711 (step S703). The first sealing member 714 may be a metal gasket or a resin O-ring.

The second flange member 712 is placed over the first flange member 711 (step S704). The convex portion 712a of the second flange member 712 enters the inside of the first flange member 711, and the first seal member 714 is sandwiched between the convex portion 712a and the flange 721 on the small diameter side. The second flange member 712 is held in this state by the projection 712a entering the inside of the first flange member 711 . Then, the second fixing holes 712 b of the second flange member 712 are aligned in the circumferential direction so as to face the second fixing holes 711 b of the first flange member 711 .

Next, while the second sealing member 715 is sandwiched between the body portion 712d of the second flange member 712 and the flange 722 on the large diameter side, the flange 722 on the large diameter side is arranged to overlap the second flange member 712. (Step S705). The second sealing member 715 may be a metal gasket or a resin O-ring. Then, the fixing holes of the flange 722 on the large diameter side are aligned in the circumferential direction so as to face the second fixing holes 712b of the second flange member 712 and the second fixing holes 711b of the first flange member 711. .

Next, screws are commonly inserted into the second fixing hole 711b of the first flange member 711, the second fixing hole 712b of the second flange member 712, and the fixing hole of the flange 722 on the large diameter side. The flange member 711 and the second flange member 712 are fastened together with the flange 722 on the large diameter side (step S706). At this time, the first seal member 714 is crushed between the convex portion 712a of the second flange member 712 and the flange 721 on the small diameter side, so that the second flange member 712 and the flange 721 on the small diameter side are airtightly connected. be done. Further, the second sealing member 715 is crushed between the body portion 712d of the second flange member 712 and the large diameter side flange 722, so that the second flange member 712 and the large diameter side flange 722 are airtight. concatenated.

According to the present embodiment as described above, the first flange member 711 is screwed to the flange 721 on the small diameter side, and the first flange member 711 and the second flange member 712 are connected to the flange 722 on the large diameter side. By being tightened together, the flange 721 on the small diameter side and the flange 722 on the large diameter side are airtightly connected via the connecting device 710 . Since the connecting device 710 does not require a cylindrical main body 793 (see FIG. 7A) unlike the conventional connecting pipe 790, the pipe distance can be greatly shortened. According to actual verification by the inventors of the present invention, the pipe distance was 100 mm in the conventional connecting pipe 790, whereas the pipe distance can be shortened to 17.5 mm in the present embodiment. As a result, the space can be saved and the exhaust efficiency can be improved. Further, for example, when the pipe extends horizontally, the load bearing capacity of the connecting portion can be increased.

Further, according to the present embodiment, since the tip of the convex portion 712a of the second flange member 712 is tapered 712c, the gap between the convex portion 712a of the second flange member 712 and the flange 721 on the small diameter side is reduced. When the first seal member 714 is crushed by , the load applied from the convex portion 712a to the first seal member 714 increases, making it easier to crush.

Further, according to the present embodiment, the outer diameter of the first flange member 711 and the outer diameter of the second flange member 712 are equal to the outer diameter of the flange 722 on the large diameter side. Space is saved because the second flange member 712 does not protrude in the radial direction.

[Description of symbols]
710 connecting device 711 first flange member 711a first fixing hole 711b second fixing hole 711c counterbore 712 second flange member 712a convex portion 712b second fixing hole 712c taper 712d body portion 714 first sealing member 715 second Seal member 721 Flange 722 on the small diameter side Flange on the large diameter side

(Seventh embodiment)

[Technical field]
The present embodiment relates to an electron beam generator, and more particularly to an electron beam generator that generates a plurality of electron beams.

[Background technology]
Some electron beam irradiation apparatuses irradiate a sample with a single electron beam, while others irradiate a plurality of electron beams. In the latter case, the electron beam generator needs to generate multiple electron beams. In this case, it is conceivable to provide a diaphragm with a plurality of apertures, and to separate one electron beam into a plurality of electron beams by passing one electron beam through the plurality of apertures.

[Problems to be solved by the present embodiment]
However, such an electron beam generator is inefficient because the electron beam is cut by the diaphragm.

Accordingly, an object of the present embodiment is to provide an electron beam generator that efficiently generates a plurality of electron beams and an electron beam irradiation apparatus that includes such an electron beam generator.

[Means to solve the problem]

<Aspect 1>
a photocathode that receives light and emits an electron beam;
a diaphragm facing the photocathode;
a first insulating layer provided between the diaphragm and the photocathode;
a plurality of electrodes provided between the diaphragm and the first insulating layer;
a second insulating layer provided between the aperture and the plurality of electrodes;
An electron beam generator, wherein openings are provided in the diaphragm, the second insulating layer, each of the plurality of electrodes, and the first insulating layer so as to expose a plurality of portions of the photocathode.

<Aspect 2>
a first insulating layer provided with a plurality of openings;
a photocathode having a plurality of photoelements disposed in at least a portion of the plurality of apertures for receiving light and emitting electron beams;
a diaphragm facing the first insulating layer;
a plurality of electrodes provided between the diaphragm and the first insulating layer;
a second insulating layer provided between the aperture and the plurality of electrodes;
An electron beam generator, wherein an opening is provided in each of the diaphragm, the second insulating layer and the plurality of electrodes so as to expose each of the plurality of photoelectric elements.

<Aspect 3>
a photocathode that receives light and emits an electron beam;
a plurality of electrodes provided with openings at positions facing at least part of the photocathode and separated from the photocathode;
First and second insulating layers having openings and sandwiching the plurality of electrodes so as not to block the openings, the first insulating layer being closer to the photocathode and the insulating layer being farther from the photocathode. a second insulating layer on the side;
An electron beam generator comprising: an aperture provided with an opening, and provided facing the second insulating layer so as not to block the opening of the second insulating layer.

<Aspect 4>
4. The electron beam generator according to any one of aspects 1 to 3, wherein a voltage can be applied independently to each of the plurality of electrodes.

<Aspect 5>
5. The method according to any one of aspects 1 to 4, wherein one of a first voltage for emitting an electron beam and a second voltage for not emitting an electron beam can be selectively applied to each of the plurality of electrodes. electron beam generator.

<Aspect 6>
One of a first voltage equal to or higher than a threshold voltage determined according to the work function of the photocathode and the frequency of light irradiated onto the photocathode and a second voltage lower than the threshold voltage is applied to each of the plurality of electrodes. 5. The electron beam generator according to any one of aspects 1 to 4, which can be applied by switching between .

<Aspect 7>
7. The electron beam generator according to any one of modes 1 to 6, wherein each of the plurality of electrodes is composed of a plurality of poles.

The electron beam generator can be applied not only to the electron beam irradiation device but also to the exposure device and the inspection device.

[Effect of this embodiment]
An electron beam can be generated efficiently.

[Brief description of the drawing]
[FIG. 8A] A sectional view of the electron beam generator 112 according to the present embodiment.
[FIG. 8B] A view of the photocathode 82 viewed from below.
[FIG. 8C] A view of the insulating layer 83 viewed from below.
[FIG. 8D] A view of the electrode array 84 from below.
[FIG. 8E] A diagram of the diaphragm 86 viewed from below.
[FIG. 8F] Simulation results showing the shape of the emitted electron beam when the voltage applied to each electrode 840 is -1.00V.
[FIG. 8G] Simulation results showing the shape of the emitted electron beam when the voltage applied to each electrode 840 is -0.50V.
[FIG. 8H] Simulation results showing the shape of the emitted electron beam when the voltage applied to each electrode 840 is -0.13V.
[FIG. 8I] Simulation results showing the shape of the emitted electron beam when the voltage applied to each electrode 840 is 0.00V.
[FIG. 8J] Simulation results showing the shape of the emitted electron beam when the voltage applied to each electrode 840 is +2.00V.
[FIG. 8K] Simulation results showing the shape of the emitted electron beam when the voltages applied to the adjacent electrodes 840a-840c are -0.50V, -0.13V and -0.50V, respectively.
[FIG. 8L] A sectional view of an electron beam generator 112' according to a modification of FIG. 8A.
[FIG. 8M] A view of the photocathode 82 viewed from below.
[FIG. 8N] A diagram showing a variation of the electrode 840. [FIG.
[FIG. 8O] A diagram showing a variation of the electrode 840. [FIG.
[FIG. 8P] A diagram showing a variation of the electrode 840. [FIG.
[FIG. 8Q] A diagram showing a variation of the electrode 840. [FIG.

[Mode for carrying out the present embodiment]
FIG. 8A is a cross-sectional view of the electron beam generator 112 according to this embodiment. The electron beam generator 112 includes a substrate 81 made of an insulating material such as glass, a photocathode 82, an insulating layer 83, an electrode array 84 composed of a plurality of electrodes 840, an insulating layer 85, and an aperture 86. ing. Although the electron beam generator 112 is controlled by the electron beam controller 132 of FIG. 1A, the electron beam controller 132 may be part of the electron beam generator 112 .

FIG. 8B is a view of the photocathode 82 viewed from below. The photocathode 82 is composed of a photoelectron-generating material with a low work function. Photocathode 82 is rectangular and formed on substrate 81 (see FIG. 8A). A reference voltage (for example, GND) is applied to the photocathode 82 . The photocathode 82 emits an electron beam upon receiving light such as ultraviolet rays and laser light.

FIG. 8C is a view of the insulating layer 83 viewed from below. The insulating layer 83 is made of ceramic, Kapton sheet, or the like. The outer contour of the insulating layer 83 is rectangular, and a plurality of substantially circular openings 83a are formed in a matrix inside. The insulating layer 83 is arranged directly under the photocathode 82 (see FIG. 8A), whereby a part of the photocathode 82 is covered with the insulating layer 83, but the other part (that is, the part facing the opening 83a) is covered with the insulating layer 83. Exposed.

FIG. 8D is a bottom view of the electrode array 84. FIG. Each electrode 840 has a substantially square outer contour and a substantially circular opening 84a formed therein. This opening 84 a is smaller than the opening 83 a of the insulating layer 83 . Such electrodes 840 are arranged in a matrix just below the insulating layer 83 (see FIG. 8A). More specifically, the electrode array 84 is arranged such that the opening 84a of each electrode 840 is positioned in the center of the opening 83a of the insulating layer 83. As shown in FIG. The distance from the photocathode 82 to the electrode array 84 is, for example, several μm to several mm.

Also, as shown in FIG. 8D, a wiring 84b is connected from each of the electrodes 840 to the outside (not shown in FIG. 8A). A predetermined voltage (details will be described later) is applied to each electrode 840 via each wiring 84b in accordance with the control of the electron beam controller 132 (FIG. 1A). The wiring 84b may be printed on the insulating layer 83 or the insulating layer 85. FIG.

In FIG. 8A, the insulating layer 85 has the same shape as the insulating layer 83 and also has an opening 85a. The electrode 840 is sandwiched between the insulating layers 83 and 85, but the opening 84a is not closed.

FIG. 8E is a diagram of the diaphragm 86 viewed from below. The diaphragm 86 is made of metal such as tantalum or molybdenum. The diaphragm 86 has a rectangular outline, and has a plurality of substantially circular openings 86a formed therein in a matrix. This opening 86 a is smaller than the opening 84 a of electrode 840 . Such an aperture 86 is arranged directly under the insulating layer 85 (see FIG. 8A). More specifically, the aperture 86 is arranged so that the aperture 86a of the aperture 86 is positioned at the center of the aperture 85a of the insulating layer 85. As shown in FIG. In other words, the diaphragm 86 covers the insulating layer 85 so that the insulating layer 85 is not exposed.

An anode (not shown) is provided below the diaphragm 86, and a voltage higher than the reference voltage by several volts to several tens of kV is applied.

As described above with reference to FIGS. 8A to 8E, the diaphragm 86 faces the photocathode 82 in the electron beam generator 112 . An insulating layer 83 is provided between the diaphragm 86 and the photocathode 82 . A plurality of electrodes 840 are provided between the diaphragm 86 and the insulating layer 83 . Furthermore, an insulating layer 85 is provided between the diaphragm 86 and the plurality of electrodes 840 . Openings 86a, 85a, 84a, and 83a are provided in the diaphragm 86, the insulating layer 85, the plurality of electrodes 840, and the insulating layer 83, respectively, so that the photocathode 82 is exposed at a plurality of locations.

In other words, each of the plurality of electrodes 840 is provided with an opening 84 a at a position facing at least a portion of the photocathode 82 and is separated from the photocathode 82 . The insulating layers 83 and 85 having the openings 83a and 85a sandwich the plurality of electrodes 840 so as not to block the openings 84a. A diaphragm 86 having an opening 86a formed therein is provided facing the insulating layer 85 so as not to block at least a portion of the opening 85a of the insulating layer 85. As shown in FIG.

Electron beams from exposed positions on the photocathode 82 pass through the openings 86a, 85a, 84a, and 83a by the electron beam generator 112 configured as described above.

This electron beam generator 112 operates as follows.
Each electrode 840 can be applied by switching between an ON voltage for emitting an electron beam and an OFF voltage for not emitting an electron beam under the control of the electron beam controller 132 (FIG. 1A). The ON voltage is a voltage higher than the reference voltage applied to the photocathode 82, and the OFF voltage is a voltage lower than the reference voltage. As an example, when the reference voltage is GND, the on-voltage is about 0 to several volts, and the off-voltage is about minus several volts.

When an off-voltage is applied to a certain electrode 840, a negative barrier is generated on the surface of the photocathode 82 and no electron beam is emitted.

When an on-voltage is applied to a certain electrode 840, the electron beam is extracted and emitted through the opening 84a of the electrode 840 because no barrier occurs.

When applying the present electron beam generator 112 to an electron beam irradiation apparatus, the electron beam control section 132 may commonly apply an ON voltage or an OFF voltage to all the electrodes 840 . On the other hand, when applying the present electron beam generator 112 to an exposure apparatus or an inspection apparatus, it is desirable that the electron beam control section 132 can apply an ON voltage or an OFF voltage to the plurality of electrodes 840 individually. As a result, the irradiation area of the electron beam can be finely controlled, and for example, a drawing pattern for an exposure apparatus can be created.

In this way, the aperture 86a of the diaphragm 86a is positioned opposite the aperture 84a of the electrode 840, so that most of the electron beam from the photocathode 82 is not cut off by the diaphragm 86a, and the sample W can be irradiated efficiently. well available. In addition, since the impact energy on the diaphragm 86 is low, almost no X-rays are generated, eliminating the need for X-ray countermeasures.

Further, insulating layers 83 and 85 are arranged facing the photocathode 82 . Therefore, even if positive ions are generated by the collision of the electron beam with the gas, these positive ions hardly reach the photocathode 82, and deterioration of the photocathode 82 can be suppressed.

Also, since the distance from the substrate 81 to the diaphragm 86 can be shortened, the optical path length is shortened. Since a large current does not flow from the photocathode 82 to the diaphragm 86, it is possible to suppress deterioration in resolution caused by the Boersch effect.

Furthermore, when it is not desired to irradiate the sample W with the electron beam (so-called blanking), for example, it is not necessary to greatly deflect the electron beam using the deflector 115 (FIG. 1A), and an off voltage may be applied to the electrode 840. . Since the electron beam itself is not generated, contamination can be suppressed.

It is desirable that the electron beam controller 132 can also apply a voltage to the diaphragm 86 as well. The electron beam emitted by the applied voltage can be deflected, and the electron beam generator 112 can also serve as a deflector.

Subsequently, simulation results of the electron beam generator 112 shown in FIG. 8A are shown. In FIG. 8A, the substrate 81 was a glass substrate. The insulating layers 83 and 85 have a thickness of 10 μm, and the openings 83a and 85a have a diameter of 10 μm. Each electrode 840 had a thickness of 2 μm, and the diameter of the opening 84a was 6 μm. The diaphragm 86 had a thickness of 2 μm and the diameter of the opening 86a was 4 μm. The distance between the center of the opening 84a in one electrode 840 and the center of the opening 84a in the adjacent electrode 840 was set to 30 μm.

As a calculation condition, the electron emission energy Eem was set to 0.2 eV. The electron emission energy Eem is expressed by the following formula.
Eem=hν−W
Here, h is Planck's constant, ν is the frequency of light (for example, ultraviolet rays) irradiated to the photocathode 82 , and W is the work function of the photocathode 82 .

8F-8J show the emitted electron beams when the voltages applied to each electrode 840 are −1.00 V, −0.50 V, −0.13 V, 0.00 V and +2.00 V, respectively. It is a simulation result showing the shape of

In FIGS. 8F and 8G, the applied voltages (−1.00 V and −0.50 V, respectively) are lower than the electron emission energy Eem so that the −0.2 V equipotential line is at the photocathode 82 and the electrode array 84 . formed between Therefore, the electron beam does not reach the electrode array 84 due to this negative barrier.

In FIG. 8H, no barrier is formed between the photocathode 82 and the electrode array 84 because the applied voltage is higher than the electron emission energy Eem. Since the applied voltage is negative (−0.13 V), the electron beam is bent in a direction away from the inner peripheral edge of the electrode 840 (in a direction toward the center of the opening 84a) (in other words, the electron beam is constricted). ) and passes through the aperture 86 a of the diaphragm 86 .

In FIG. 8I, no barrier is formed between the photocathode 82 and the electrode array 84 because the applied voltage is higher than the electron emission energy Eem. Also, since the applied voltage is 0.00 V, the electron beam passes through the aperture 84 a of the electrode 840 without passing through the aperture 86 a of the diaphragm 86 .

In FIG. 8J, no barrier is formed between the photocathode 82 and the electrode array 84 because the applied voltage is higher than the electron emission energy Eem. Since the applied voltage is positive (+2.00 V), the electron beam is bent (in other words, the electron beam spreads) in a direction approaching the inner peripheral end of the electrode 840 (a direction away from the center of the opening 84a). ), through the aperture 86 a of the diaphragm 86 .

Thus, an electron beam is emitted by applying to the electrode 840 a voltage higher than the threshold voltage (−0.2 V in this example) corresponding to the electron emission energy Eem (−0.2 eV in this example). In other words, it is only necessary to switch between a voltage equal to or higher than the threshold voltage and a voltage lower than the threshold voltage and apply the voltage to the electrode 840 .

FIG. 8K is a simulation result showing the shape of the emitted electron beam when the voltages applied to adjacent electrodes 840a-840c are -0.50V, -0.13V and -0.50V, respectively. As shown, −0.50 V (<Eem) is applied to the electrodes 840a and 840c, so the electron beam does not reach these electrodes 840a and 840c. On the other hand, since -0.13 V (>Eem) is applied to the electrode 840b, the electron beam passes through the aperture 86a of the diaphragm 86 corresponding to the electrode 840b. Thus, it is possible to control whether or not to emit an electron beam for each electrode 840 .
FIG. 8L is a cross-sectional view of an electron beam generator 112' according to a modification of FIG. 8A. The following description focuses on differences from FIG. 8A.

FIG. 8M is a view of the photocathode 82 viewed from below. The shape of the photocathode 82 is different from the electron beam generator 112 of FIG. 8A. The photoelectric surface 82 is composed of a plurality of substantially circular photoelectric elements 82b arranged in a matrix. Such a photocathode 82 is formed on the substrate 81 (see FIG. 8L).

Returning to FIG. 8L, the shapes of insulating layer 83, electrode array 84, insulating layer 85 and diaphragm 86 are similar to those shown in FIGS. 8C-8E, respectively. However, the insulating layer 83 is formed on the substrate 81 so that the photoelectric element 82a is accommodated in the opening 83a.

Thus, in the electron beam generator 112', the insulating layer 83 having a plurality of openings 83a is provided on the substrate. A photoelectric element 82b of the photoelectric surface 82 is arranged in at least part of the opening 83a. A diaphragm 86 faces the insulating layer 83 . A plurality of electrodes 840 are provided between the diaphragm 86 and the insulating layer 83 . Also, an insulating layer 85 is provided between the diaphragm 86 and the plurality of electrodes 840 . Openings 86a, 85a, and 84a are provided in the aperture 86, the insulating layer 85, and the electrodes 840, respectively, so that the photoelectric elements 82a are exposed.

In other words, each of the plurality of electrodes 840 is provided with an opening 84 a at a position facing at least a portion of the photocathode 82 and is separated from the photocathode 82 . The insulating layers 83 and 85 having the openings 83a and 85a sandwich the plurality of electrodes 840 so as not to block the openings 84a. A diaphragm 86 having an opening 86a formed therein is provided facing the insulating layer 85 so as not to block at least a portion of the opening 85a of the insulating layer 85. As shown in FIG.

In the electron beam generator 112′ shown in FIG. 8L as well, the electron beams from the photoelectric elements 82a on the photocathode 82 pass through the openings 84a, 85a, and 86a. Operate.

8N-8Q are diagrams showing variations of the electrode 840. FIG. As shown in the figures, the contour of electrode 840 may be substantially circular. And the electrodes 840 may be circular holes (FIG. 8N), quadrupoles (FIG. 8O), octapoles (FIG. 8P), twelve poles (FIG. 8Q), and so on. As shown in FIGS. 8O to 8Q, when the electrode 840 is composed of a plurality of poles, the electrode 840 can It functions as a lens and deflector.

As described above, in this embodiment, a plurality of electrodes 840 having apertures 84a are arranged to face the photocathode 82, and the diaphragm 86 having apertures 86a is arranged at a position facing the apertures 84a. . Therefore, the number of electron beams cut by the diaphragm 86 is reduced, and a plurality of electron beams can be efficiently generated.
[Description of symbols]
81 substrate 82 photocathode 82b photoelectric element 83 insulating layer 83a opening 84 electrode array 840 electrode 84a opening 84b wiring 85 insulating layer 85a opening 86 diaphragm 86a openings 112, 112' electron beam generator

Claims (5)

An electron beam from an electron beam generator is scanned in a first direction by applying a voltage V1(t) that varies with time t to the first electrode, and a voltage V2(t) that varies with time t is applied to the second electrode. In an electron beam irradiation apparatus intended to irradiate an electron beam with a rectangular area as a target by scanning in a second direction orthogonal to the first direction, the irradiation area of the electron beam is a rectangle When it is a roughly parallelogram distorted in the first direction instead of
By applying a voltage V1(t)+kV2(t) (k is a constant) to the first electrode and applying a voltage V2(t) to the second electrode, the irradiation area of the electron beam is corrected to be rectangular. death,
The voltage V2(t) repeats N0 times that the voltage V2(t) becomes a certain value and changes to another value after the period T0 has elapsed,
The voltage V1(t) has the period T0 as a cycle , linearly increases in the first half of the period T0, and linearly decreases with the same slope in the second half of the period T0, and repeats N0 times,
The electron beam irradiation area correction method, wherein T0 and N0 respectively correspond to the lengths of the rectangle in the first direction and the lengths of the rectangle in the second direction. 2. The electron beam irradiation area correction method according to claim 1, wherein said k is set so that the electron beam irradiation area approximates a rectangle. 3. The electron beam irradiation region correction method according to claim 1, wherein the absolute value of k is set larger as the distortion in the first direction increases. An electron beam from an electron beam generator is scanned in a first direction by applying a voltage V1(t) that varies with time t to the first electrode, and a voltage V2(t) that varies with time t is applied to the second electrode. In an electron beam irradiation apparatus intended to irradiate an electron beam targeting a rectangular area by scanning in a second direction orthogonal to the first direction by applying
applying a voltage V1(t)+kV2(t) (k is a constant) to the first electrode when the irradiation area of the electron beam is not a rectangle but a substantially parallelogram distorted in the first direction; an electron beam controller that applies a voltage V2(t) to the second electrode, thereby correcting the irradiation area of the electron beam to be rectangular;
The voltage V2(t) repeats N0 times that the voltage V2(t) becomes a certain value and changes to another value after the period T0 has elapsed,
The voltage V1(t) has the period T0 as a cycle , linearly increases in the first half of the period T0, and linearly decreases with the same slope in the second half of the period T0, and repeats N0 times,
The electron beam irradiation device, wherein T0 and N0 respectively correspond to the length in the first direction and the length in the second direction of the rectangle. an electron beam generator for generating an electron beam;
a first electrode that deflects the electron beam from the electron beam generator in a first direction;
a second electrode that deflects the electron beam from the electron beam generator in a second direction orthogonal to the first direction;
an electron beam controller for controlling the voltage applied to the first electrode and the second electrode;
An electron beam from an electron beam generator is scanned in the first direction by applying a voltage V1(t) that varies with time t to the first electrode, and a voltage V2(t) that varies with time t is applied to the first electrode. By scanning in the second direction by applying voltage to the second electrode, the irradiation area of the electron beam is not rectangular but in the first direction, although it is intended to irradiate the electron beam with a rectangular area as a target. When it is a distorted approximate parallelogram,
The electron beam controller applies a voltage V1(t)+kV2(t) (where k is a constant) to the first electrode and a voltage V2(t) to the second electrode, thereby generating an electron beam. Correct the irradiation area so that it becomes a rectangle,
The voltage V2(t) repeats N0 times that the voltage V2(t) becomes a certain value and changes to another value after the period T0 has elapsed,
The voltage V1(t) has the period T0 as a cycle , linearly increases in the first half of the period T0, and linearly decreases with the same slope in the second half of the period T0, and repeats N0 times,
The electron beam irradiation device, wherein T0 and N0 respectively correspond to the length in the first direction and the length in the second direction of the rectangle.

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