JP2003277919A - Laser ablation method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser ablation method and device that can surely collect micro-grains as well as removing coarse grains. <P>SOLUTION: A first rotary plate 6 is rotatably driven which is arranged opposite to a substrate S for collecting grains and which is provided with a slit 6a for allowing grains to pass, while a pulsed laser beam is generated from a laser beam source 2 in synchronization with the rotation of the first rotary plate 6. The target 5 arranged on the side opposite from the substrate S with the first rotary plate in-between is irradiated by the laser beam and made to release the grains. With the slit 6a of the first rotary plate 6 traversing a grain release route from the target 5 to the substrate S, the released grains in a prescribed speed range are passed through the slit 6a, so that the released grains are selectively collected with the substrate S. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser ablation method and apparatus, and more particularly to a method and apparatus for reducing coarse particles generated by laser ablation.

[0002]

2. Description of the Related Art Conventionally, various methods have been proposed to reduce coarse particles caused by laser ablation.

For example, Japanese Patent Laid-Open No. 7-180042 and
In K.Kinoshita, et al., J.Appl.Phys.33 (1994) L417 (hereinafter referred to as Kinoshita et al.), A shield plate is provided between the target and the substrate to remove coarse particles during film formation. A method of removing it is proposed.

In addition, B. Holzapfel, et al., Appl. Phys. Le
tt.61 (1992) 3178. (hereinafter referred to as Holzapfel), a so-called off-axial method in which a substrate is placed parallel to the plume of the laser has been conventionally known. This method uses the principle that coarse particles such as clusters fly in parallel with the substrate and thus are less likely to adhere to the substrate, whereas fine particles have Brownian motion and thus tend to adhere to the substrate.

On the other hand, some methods for suppressing the generation of coarse particles from the target have been proposed. For example, Japanese Patent Application Laid-Open No. 10-36959 discloses a technique in which a target being irradiated with laser light is heated to suppress the generation of coarse particles.

[0006] Further, Laser Research, 20 (1992) 355. (Nagaishi et al.) Proposes a method of suppressing the generation of coarse particles by densifying a target.

Further, as a method completely different from the above-mentioned methods, as a method of laser heat processing, 7 (2000) 107.
(Yoshida et al.) Proposes a method of classifying nanoparticles using DMA (electromobility classification method) and then depositing them.

[0008]

However, the methods in the above-mentioned respective prior arts have various problems as described below.

That is, according to the method described in Japanese Patent Laid-Open No. 7-180042 or Kinoshita et al., It is not possible to sufficiently remove coarse particles, and the target-substrate are shielded by a shield plate, so that deposition on the substrate is performed. There is a problem that the speed becomes extremely slow.

Further, the off-axial method has a problem in that, like the method using the shield plate described above, the adhesion efficiency of fine particles is poor and coarse particles having a slow speed cannot be completely removed.

Further, the method disclosed in Japanese Patent Laid-Open No. 10-36959 has a problem in that the substrate is simultaneously heated by the radiant heat from the heated target, which deteriorates the quality of the deposited film.

In addition, the method of Nagaishi et al. Has a problem that the types of targets are limited, and when the laser irradiation time is long, the target surface becomes rough and coarse particles are easily generated.

Further, in the DMA method, since a classifier is passed on the way, it is necessary to separate the laser ablation and the film forming chamber from each other, so that the collection efficiency of fine particles is poor and the process up to film formation is poor. There was a problem that it took a long time.

In view of the above problems, it is an object of the present invention to provide a laser ablation method and apparatus capable of removing coarse particles and reliably collecting fine particles.

[0015]

In order to achieve this object, a laser ablation method according to a first aspect of the present invention is to irradiate a target with a laser beam so that particles are emitted toward a collecting member and a laser beam is emitted. By allowing the release particles to reach the collecting member within a predetermined period after the light irradiation and preventing the release particles from reaching the outside of the predetermined period, the release particles in a predetermined speed range are collected by the collecting member. It is characterized by selectively collecting.

There is a correlation between the particle velocity and the particle size, and the time required from the generation of the laser light to the arrival of the particles at the collecting member differs depending on the particle size. Therefore, within a predetermined period after the generation of the laser light. By allowing passage of the emitted particles to the repair member and preventing passage of the emitted particles to the collecting member outside the predetermined period, only particles having a particle size within a predetermined range are selectively collected. can do.

In the laser ablation method according to a second aspect of the present invention, the movable member is disposed so as to face the collecting member that collects the particles and has a passage portion that allows the particles to pass therethrough. Pulsed laser light is generated from a laser light source in synchronization with the movement of the member, and the target is arranged on the opposite side of the trapping member with the movable member sandwiched between them to emit the laser light to emit particles. While the passage portion of the movable member traverses a particle emission path from the target to the collection member, the emission particles in a predetermined velocity range are passed to the passage portion, thereby collecting the emission particles. It is characterized by selectively collecting in.

Therefore, since there is a correlation between the particle velocity and the particle size, only particles emitted within a predetermined velocity range are passed through the passage of the movable member to select particles having a uniform particle size. Can be collected as a target. Therefore, the low-speed coarse particles emitted from the target are removed, and only the high-speed ultrafine particles are selectively collected to form a high-quality thin film having a highly uniform and smooth surface on the collecting member. can do. Further, the laser ablation and the film formation can be performed simultaneously and in a short time without being limited by the type and temperature of the target.

Further, in the laser ablation method according to a third aspect of the present invention, as the movable member, a rotary plate rotationally driven by a drive source and having a slit is used, and the laser light source is synchronized with the rotation of the rotary plate. A more pulsed laser beam is generated, and while the slit is traversing the particle emission path by the rotation of the rotary plate, the emitted particles in a predetermined velocity range are passed through the slit.

Therefore, by passing only the particles emitted in the predetermined velocity range to the slit of the rotary plate, it is possible to reliably and selectively collect the particles having a uniform particle size.

Further, in the laser ablation method according to a fourth aspect, depending on the size of the particles to be collected, laser light generation in the laser light source and crossing of the particle emission path of the slit in the rotary plate are performed. The feature is that the timing of is set.

Therefore, the particle velocity varies depending on the particle size, and the time from the generation of the laser beam to the arrival of the emitted particles at the rotating plate is different.
By arbitrarily setting the timing of laser light generation in the laser light source and the crossing of the slit in the rotating plate across the particle emission path, only particles of a desired size can be selectively collected.

The laser ablation method according to a fifth aspect is characterized in that the generation of laser light in the laser light source and the crossing of the slit in the rotary plate across the particle emission path are synchronized.

Therefore, the ultra-fine particles emitted from the target at a high speed reach the rotating plate within a very short time after the laser beam is generated. Therefore, the laser beam is generated in the laser light source and the particle is emitted from the slit in the rotating plate. By synchronizing with the crossing of the path, only ultrafine particles can be selectively collected.

Further, in the laser ablation method according to the sixth aspect, the particle diameter is about 100 nm into the slit of the rotating plate.
It is characterized in that the timing of generation of laser light in the laser light source and the crossing of the slit in the rotary plate across the particle emission path are set so that only the following ultrafine particles are selectively passed.

Therefore, the particle diameter is about 100 in the slit of the rotating plate.
By selectively passing only ultrafine particles of nm or less to collect, it is possible to form a high quality thin film having high uniformity and smooth surface without adhesion of coarse particles on the collecting member. it can.

The laser ablation device according to a seventh aspect of the present invention is a movable member which is driven by a driving source and is arranged to face a collecting member which collects particles, and which has a passage portion which allows passage of the particles. And a synchronization signal generating means for generating a synchronization signal by detecting the movement of the movable member,
A laser light source that receives a synchronization signal from the synchronization signal generation means and generates a pulsed laser beam based on the synchronization signal, and a laser light source that is disposed on the opposite side of the trapping member with the movable member sandwiched therebetween. A target that emits particles by irradiation with laser light generated from a light source, and the passing portion of the movable member traverses a particle emission path from the target to the collecting member, and within a predetermined speed range. It is characterized in that the emission particles are selectively collected by the collection member by passing the emission particles to the passage portion.

Therefore, the movable member in which the passage portion is formed is driven by the drive source, the synchronization signal generating means detects the movement of the movable member and generates a synchronization signal, and the laser light source
Pulsed laser light is generated based on the synchronization signal generated by the synchronization signal generation means. When the target is irradiated with the laser light, the particles are emitted toward the collecting member. At this time, while the passage part traverses the particle emission path from the target to the collection member due to the movement of the movable member, the particles emitted from the target in the predetermined velocity range are passed to the passage part to selectively capture the particles. You can gather.

That is, since there is a correlation between the particle velocity and the particle size, only particles emitted within a predetermined velocity range are allowed to pass through the passage portion to selectively capture particles having a uniform particle size. You can gather. Therefore, with a simple structure, the low-speed coarse particles emitted from the target can be reliably removed, and only the high-speed ultrafine particles can be selectively collected, and a highly uniform and smooth surface can be formed on the collecting member. It is possible to form a high quality thin film having the same. Further, the laser ablation and the film formation can be performed simultaneously and in a short time without being limited by the type and temperature of the target.

Further, in the laser ablation device according to claim 8, the movable member is constituted by a rotary plate which is rotationally driven by a drive source and has a slit formed therein,
The laser light source generates pulsed laser light from the laser light source in synchronization with the rotation of the rotating plate, and while the slit crosses the particle emission path by the rotation of the rotating plate, particles emitted within a predetermined velocity range. Is configured to pass through the slit.

Therefore, by passing only the particles emitted in the predetermined velocity range through the slit of the rotary plate, it is possible to reliably and selectively collect the particles having a uniform particle size with a simple structure.

[0032]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of a laser ablation method and apparatus embodying the present invention will be described below with reference to the drawings.

First, a schematic structure of the laser ablation apparatus 1 according to this embodiment will be described with reference to FIG.

The laser ablation device 1 includes a laser light source 2, a condenser lens 3, a vacuum container 4, and a target 5.
, First rotary plate 6, second rotary plate 7, and variable motor 8
And an optical switch 9 and a trigger circuit 10. The first rotary plate 6 is the movable member of the present invention, the variable motor 8 is the drive source, the optical switch 9 and the trigger circuit 1
Reference numeral 0 constitutes each of the synchronizing signal generating means.

The laser light source 2 is a device for generating pulsed laser light (hereinafter referred to as pulsed laser light) by generating a laser pulse signal based on the synchronization signal received from the trigger circuit 10.

The condenser lens 3 is an optical system member for guiding the pulsed laser light generated from the laser light source 2 into the vacuum container 4 and condensing it on the target 5 arranged in the vacuum container 4.

The vacuum container 4 is a container whose interior is kept vacuum, and in which the target 5, the first rotating plate 6, and the substrate S on which the particles emitted from the target 5 are attached or deposited are arranged. It The vacuum container 4 is provided with a window 4a made of a transparent material such as glass, and the pulsed laser light guided by the condenser lens 3 can enter the vacuum container 4. Further, the vacuum container 4 is provided with an exhaust port 4b for exhausting gas generated by execution of laser ablation.

The target 5 is a material for supplying a raw material of fine particles, and for example, a semiconductor material such as silicon, a metal material, an inorganic material, an organic material or the like and a composite material thereof can be used. The target 5 is located in the vacuum container 4 at a position where laser light can be irradiated, is arranged on the opposite side of the substrate S with the first rotating plate 6 interposed therebetween, and is rotationally driven by a driving unit such as a motor (not shown).

As shown in FIGS. 1 and 2, the first rotary plate 6 is a disk-shaped member that is fixed to the rotary shaft 8a of the variable motor 8 and is driven to rotate, and the particles emitted from the target 5 are A slit 6a for passing the slit is formed. The first rotary plate 6 is provided between the target 5 and the substrate S in the vacuum container 4, and is arranged so as to face the substrate S. Therefore, the first rotating plate 6 is arranged at a position that blocks the particle emission path from the target 5 to the substrate S, and while the slit 6a crosses the particle emission path by the rotation of the first rotating plate 6 (that is, the slit 6a is The emitted particles are allowed to reach the substrate S only (while passing through the position facing the substrate S), and otherwise the emitted particles are blocked from reaching the substrate S. The size of each part of the first rotary plate 6 is set according to the application and various conditions. For example, the slit 6a has a diameter of about 10 mm, and the distance from the center of rotation of the first rotary plate 6 to the center of the slit 6a. (Turning radius) is 50m
It can be set to about m. Where the slit 6a
Serves as the passage portion of the present invention, and the substrate S constitutes a particle collecting member.

The second rotary plate 7 is arranged outside the vacuum container 4 and fixed to the rotary shaft 8a of the variable motor 8. Therefore, the second rotary plate 7 is connected to the vacuum container 4 via the rotary shaft 8a.
It is coaxially connected to the first rotary plate 6 inside and is rotationally driven together with the first rotary plate 6 by a variable motor 8. Also,
The second rotary plate 7 is formed with a slit 7a for rotation detection by the optical switch 9.

The variable motor 8 is a drive source that is provided outside the vacuum container 4 and rotationally drives the first and second rotating plates 6 and 7 fixed to the rotating shaft 8a extending in the axial direction.

A part of the optical switch 9 is the second rotary plate 7
A device for detecting the passage of the slit 7a associated with the rotation of the second rotary plate 7 and transmitting and outputting an optical signal each time the detection is performed. Is. By detecting the passage of the slit 7a, it is possible to detect the rotation speed of the first rotary plate 6 that rotates in the same manner as the second rotary plate 7.

The trigger circuit 10 is a circuit having a function of synchronizing the optical signal transmitted from the optical switch 9 with the laser pulse signal (pulse number) of the laser light source 2, and outputs a synchronization signal to the laser light source 2.

Next, the operation of the laser ablation device 1 having the above-mentioned structure will be described with reference to FIG.

When the variable motor 8 rotates, the first rotary plate 6 and the second rotary plate 7 mounted on the rotary shaft 8a are rotationally driven. The optical switch 9 detects the passage of the slit 7 a of the second rotary plate 7 that is rotationally driven and sends an optical signal to the trigger circuit 10. As described above, the second rotating plate 7 and the first
Since it is coaxially fixed to the rotary plate 6, the rotation of the first rotary plate 6 can be detected by detecting the rotation of the second rotary plate 7. The trigger circuit 10 sends a synchronization signal to the laser light source 2 based on the optical signal from the optical switch 9. The laser light source 2 generates a laser pulse signal based on the synchronization signal from the trigger circuit 10 and generates pulsed laser light in synchronization with the rotation of the first rotary plate 6. The pulsed laser light generated from the laser light source 2 is guided by the condenser lens 3, enters the inside of the vacuum container 4 through the window 4a, and is condensed and irradiated onto the surface of the target 5. Target 5
When the pulsed laser light is irradiated on, a plume is formed on the surface of the target 5 and particles are emitted. Since the substrate S as a particle collecting member is arranged on the emission path of the particles emitted from the target 5, the particles scatter toward the substrate S. Since the one rotary plate 6 is provided, the first rotary plate 6 is driven to rotate.
Only the particles that have passed through the slit 6a while the slit 6a having the radius x of the rotating plate 6 traverses the particle emission path are collected by the substrate S and attached or deposited on the substrate S.

Now, the relationship between the particle size of the particles emitted from the target 5 and the average particle velocity will be described with reference to FIG. From the graph of FIG. 3, coarse particles (called debris) having a large particle size have a slow average particle speed (particle speed of 150 m / s or less), and ultrafine particles having a small particle size (called nanoparticles) have an average particle speed. It turns out that is fast.

In the present embodiment, the timing between the generation of laser light in the laser light source 2 and the passage of the slit 6a in the first rotary plate 6 at a position facing the substrate S (that is, crossing the particle emission path by the slit 6a) is set. By arbitrarily setting, only particles within a predetermined particle velocity range can be passed through the slit 6a and collected by the substrate S. Since the particle size and the particle velocity have the above-described relationship, by setting the above timing so as to collect particles within a predetermined particle velocity range, particles with uniform particle size are selectively selected. Can be collected at. Further, laser ablation and film formation can be performed simultaneously and in a short time without being limited by the type and temperature of the target 5. The above timing is preferably set so that only ultrafine particles having a particle size of about 100 nm or less are selectively passed.

Next, regarding the method of setting the timing between the generation of laser light and the passage of the slit 6a at the position facing the substrate S (that is, the crossing of the particle emission path by the slit 6a),
This will be described with reference to the plan view of the first rotary plate 6 shown in FIG. In FIG. 2, the slit angle θ represents the rotational position of the slit 6a at the time when the laser light is generated, in angle, with the center of the particle collection position on the substrate S as a reference. Therefore, when the generation of the laser light and the passage of the slit 6a at the position facing the substrate S are synchronized, the slit angle θ becomes 0 degree (FIG. 2A).

Then, for example, when the slit angle θ is set to 0 degree (FIG. 2A), only ultrafine particles having a high particle velocity which reach the rotating plate 6 immediately after the laser light is generated pass through the slit 6a. Therefore, the ultrafine particles can be selectively collected on the substrate S and attached or deposited. in this case,
The coarse particles having a low particle velocity reach the rotating plate 6 after the slit 6a has already passed the position facing the substrate S, so that the coarse particles cannot pass through the slit 6a.
It is possible to reliably remove coarse particles.

On the other hand, when the slit angle θ is increased, the slit 6a is moved to the substrate S with a delay of a predetermined time from the time when the laser light is generated.
Since the particles pass through the facing position, the ultrafine particles having a high particle velocity are blocked by the rotating plate 6, only the coarse particles having a low particle velocity pass through the slit 6a, and the coarse particles are selectively collected on the substrate S. Will be. For example, FIG. 2 (b)
Indicates the positional relationship between the slit 6a and the substrate S at the time of generation of laser light when the slit angle θ is set to 30 degrees.

Needless to say, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

For example, in the above-described embodiment, the disk-shaped first rotary plate 6 having the slits formed therein is rotationally driven to allow the emitted particles to selectively pass through the slits 6a. Is not limited to this. For example, a configuration in which a plate member having a rectangular shape is reciprocated at a predetermined timing may be used. In short, a structure capable of selectively collecting emitted particles within a predetermined velocity range by allowing the emitted particles to reach the substrate S within a predetermined period after the laser light irradiation and blocking the arrival outside the predetermined period. It is all right.

Further, in the above embodiment, the slit 6a of the first rotary plate 6 is formed in a substantially circular shape, but it may be formed in another shape such as a rectangular shape.

[0054]

EXAMPLES Next, the results of actual experiments on the laser ablation method and apparatus of this embodiment will be described.

A YAG laser device is used as the laser light source 2, and the second harmonic (wavelength 532n) of the pulse YAG laser is used.
m) is a laser output of 2 to 5 W (2.1 to 5.2 J / cm ² at a beam diameter of 3.5 mm) and a pulse number of 10 to 50 Hz.
Raised as. The beam diameter of the laser light is narrowed by a condenser lens 3 installed in front of being incident on the vacuum container 4 in the irradiation direction, and a target 5 placed in the vacuum container 4 is formed.
The above beam was focused and irradiated with a beam diameter of 3.5 mm. A silicon wafer is used as the target 5 and a predetermined rotation speed (20
Laser ablation was performed by irradiating laser light while rotating the target 5 at ˜50 rpm. The degree of vacuum in the vacuum container 4 is set to about 3 × 10 by using a diffusion pump.
^-4 Pa or less.

Target 5, first rotary plate 6, and substrate S
Were arranged so as to face each other in parallel, as shown in FIG. The number of rotations of the first rotary plate 6 and the second rotary plate 7 is set to 30.
00 rpm, the diameter x of the slit 6a is 10 mm, the distance from the center of the first rotary plate 6 to the center of the slit 6a (rotation radius r of the slit 6a) is 50 mm, the distance between the target 5 and the first rotary plate 6 is 100 mm, The pulse number of laser light was set to 50 Hz.

Here, it was confirmed that under the above-mentioned conditions, the relationship between the slit angle and the particle velocity is as shown in FIG. From the graph of FIG. 5, the particles having a high particle velocity (that is, ultrafine particles) have a slit angle θ =
It can be seen that they are concentrated near 0 degrees. The graph shows the upper limit value and the lower limit value of the particle velocity at each slit angle.

Next, the slit angle θ is set to 0 degree (example),
When set to 30 degrees (Comparative Example 1), and the first
In the case where the rotating plate 6 was not used (Comparative Example 2), laser ablation experiment was conducted, a scanning microscope (hereinafter referred to as SEM) photograph of the surface of the substrate S was taken, and the surface roughness of the film formed on the substrate S was taken. Was measured (laser output was 5
W, irradiation time is 5 minutes).

6A shows the substrate S obtained in the example, FIG. 6B shows the comparative example 1 and FIG. 6C shows the substrate S obtained in the comparative example 2.
It is a SEM photograph of the surface. In the example in which the slit angle θ is 0 degree, coarse particles are not attached and a uniform film made of fine particles is formed (FIG. 6A). That is, in the embodiment, the generation of the laser light in the laser light source 2 and the passage of the slit 6a in the first rotary plate 6 at the position facing the substrate S are synchronized, and only high-speed ultrafine particles pass through the slit 6a. , Because they are deposited on the substrate S. On the other hand, in Comparative Examples 1 and 2, it is observed that coarse particles are attached (FIGS. 6B and 6C).

Table 1 shows the results of measuring the surface roughness of the films of the substrates S obtained in Examples, Comparative Examples 1 and 2, respectively, using a stylus type surface roughness meter (Dektak). .

[0061]

[Table 1]

From Table 1, the surface roughness of the film formed by the example is 50 Å or less, which is an extremely small value as compared with Comparative Examples 1 and 2, and a smooth surface is formed. You can see that Therefore, it can be said that the laser ablation method of the present invention is effective for forming a high quality thin film.

[0063]

As described above, according to the laser ablation method of any one of claims 1 to 6 of the present invention or the laser ablation device of claim 7 or 8, the laser is ablated within a predetermined velocity range. Particles with uniform particle size can be selectively collected. Therefore, low-speed coarse particles emitted from the target are removed, and only high-speed ultrafine particles are selectively collected. The effect is that a high-quality thin film having high uniformity and a smooth surface can be formed thereon. In addition, there is an effect that laser ablation and film formation can be performed simultaneously and in a short time without being limited by the type and temperature of the target.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram schematically showing an overall configuration of a laser ablation device according to an embodiment of the present invention.

2A and 2B are plan views of a first rotating plate, FIG. 2A shows a case where the slit angle is 0 degree, and FIG. 2B shows a case where the slit angle is 30 degrees.

FIG. 3 is a graph showing the relationship between particle size and particle velocity.

FIG. 4 is an explanatory diagram showing a positional relationship between a target and a slit of the first rotating plate in the example.

FIG. 5 is a graph showing the relationship between the slit angle and the particle velocity in the example.

6A and 6B are SEM photographs of a substrate surface, FIG. 6A showing an example, FIG. 6B showing a comparative example 1, and FIG. 6C showing a comparative example 2.

[Explanation of symbols]

1 ... Laser ablation device, 2 ... Laser light source, 3 ...
Condensing lens, 4 ... Vacuum container, 5 ... Target, 6 ... First
Rotating plate (movable member, rotating plate), 6a ... Slit (passing portion), 7 ... Second rotating plate, 8 ... Variable motor (driving source), 9
... optical switch (synchronization signal generation means), 10 ... trigger circuit (synchronization signal generation means), S ... substrate (collection member).

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[Procedure amendment]

[Submission date] May 9, 2002 (2002.5.9)

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 6

[Correction method] Change

[Correction content]

[Figure 6]

Continued front page    (72) Inventor Tadashi Ito             Aichi Prefecture Nagachite Town Aichi District             Local 1 Toyota Central Research Institute Co., Ltd. (72) Inventor Akihiro Takeuchi             Aichi Prefecture Nagachite Town Aichi District             Local 1 Toyota Central Research Institute Co., Ltd. (72) Inventor Nobuo Kamiya             Aichi Prefecture Nagachite Town Aichi District             Local 1 Toyota Central Research Institute Co., Ltd. F-term (reference) 4K029 DA12 DB20 EA00

Claims (8)

[Claims] 1. Irradiating particles to a collecting member by irradiating a target with laser light, and permitting the emitted particles to reach the collecting member within a predetermined period after laser light irradiation, Moreover, the laser ablation method is characterized in that the emission particles within a predetermined velocity range are selectively collected by the collection member by blocking the arrival outside the predetermined period. 2. A movable member, which is arranged to face a collecting member for collecting particles and has a passage portion which allows passage of the particles, is driven by a pulse from a laser light source in synchronization with the movement of the movable member. -Shaped laser light is generated, particles are emitted by irradiating a laser beam to a target arranged on the opposite side of the collecting member with the movable member interposed therebetween, and the passing portion of the movable member is the target. The discharge particles are selectively collected by the collecting member by passing the discharge particles in a predetermined velocity range to the passage portion while traversing the particle discharge path further reaching the collecting member. And laser ablation method. 3. A rotary plate driven by a drive source and having slits is used as the movable member, and pulsed laser light is generated from a laser light source in synchronization with rotation of the rotary plate, The laser ablation method according to claim 2, wherein emitted particles in a predetermined velocity range are passed through the slit while the slit traverses the particle emission path due to rotation of a rotating plate. 4. The timing between generation of laser light in the laser light source and crossing of the slit in the rotary plate across the particle emission path is set according to the size of particles to be collected. Item 4. The laser ablation method according to Item 3. 5. The laser ablation method according to claim 4, wherein the generation of laser light in the laser light source and the crossing of the slit in the rotary plate across the particle emission path are synchronized. 6. A particle size of about 100 n is applied to the slit of the rotary plate.
4. The timing between generation of laser light in the laser light source and crossing of the slit in the rotary plate across the particle emission path is set so that only ultrafine particles of m or less are selectively passed. 6. The laser ablation method according to any one of 1 to 5. 7. A movable member, which is driven by a driving source and is arranged to face a collecting member that collects particles, and has a passage portion that allows passage of the particles, and a movement of the movable member is detected. A synchronization signal generating means for generating a synchronization signal, a laser light source for receiving the synchronization signal from the synchronization signal generating means, and generating a pulsed laser beam based on the synchronization signal, and the trapping device sandwiching the movable member. A target which is arranged on the opposite side of the member and which emits particles upon irradiation with laser light generated from the laser light source, wherein the passage portion of the movable member is a particle from the target to the collecting member. A feature is that the emission particles in a predetermined velocity range are allowed to pass through the passage portion while traversing the emission path, so that the emission particles are selectively collected by the collection member. Laser ablation device to. 8. The movable member is a rotary plate that is rotationally driven by a drive source and has a slit, and the laser light source is a pulsed laser from a laser light source in synchronization with the rotation of the rotary plate. The light is generated, and while the slit is traversing the particle emission path by the rotation of the rotating plate, the emitted particles in a predetermined velocity range are allowed to pass through the slit. Laser ablation device.