JP2015002132A - Gas cluster ion beam device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology that improves the shape reproducibility and stability of a gas cluster ion beam and enables beam axis adjustment work to be easily conducted in a short time regardless of the skill levels of workers.SOLUTION: A gas cluster ion beam device includes a nozzle holding member which holds a nozzle member 60 having a nozzle 61 and has a guide surface extending in a direction perpendicular to a beam axis direction P of a gas cluster ion beam. The nozzle holding member 70, a skimmer 3, and an ionization chamber 4 are integrally assembled while being positioned by a positioning structure 10. The nozzle member 60 is moved along a guide surface of the nozzle holding member 70 thereby adjusting a position of the nozzle 61 with respect to a direction perpendicular to the beam axis direction P of the gas cluster ion beam.

Description

  The present invention relates to a gas cluster ion beam apparatus, and more particularly to a cluster ion beam apparatus capable of easily adjusting an axis for improving the performance of a gas cluster ion beam.

FIG. 5 is a schematic diagram showing a configuration of a conventional gas cluster ion beam apparatus.
As shown in FIG. 5, the conventional gas cluster ion beam apparatus 101 has first and second vacuum chambers 102 and 103.

  The first vacuum chamber 102 has a conical and supersonic type nozzle 104 connected to a gas introduction system (not shown), and the rare gas introduced from the gas introduction system has a high pressure of several atmospheres or more from the nozzle. It is configured to generate a rare gas cluster by being ejected into a vacuum under pressure.

  The supersonic jet of noble gas ejected from the nozzle 104 is converted into translational motion in the adiabatic expansion process and the temperature drops, and the gas atoms (molecules) are several hundred to several thousand atoms by van der Waals force. A cluster beam is generated as a group of (molecules).

In the first vacuum chamber 102, a skimmer 105 is disposed on the downstream side of the nozzle 104 in the traveling direction of the cluster beam.
The skimmer 105 cuts out the central portion of the generated cluster beam, and the cluster beam cut out by the skimmer 105 is guided to the ionization chamber 106 provided downstream in the beam traveling direction in the second vacuum chamber 103. .

The ionization chamber 106 is provided with a hot filament 107, and the thermoelectrons emitted from the hot filament 107 are accelerated to several hundred volts by the anode grid 108 and irradiated to the cluster beam, whereby the neutral cluster beam is irradiated by electron impact. It is ionized to form a cluster ion beam.
In the second vacuum chamber 103, an electrostatic lens 109 for accelerating and converging the cluster ion beam is provided downstream of the ionization chamber 106 in the beam traveling direction.

In the prior art having such a configuration, it is difficult to match the beam axis of the gas cluster beam and the beam axis of the gas cluster ion beam.
For this reason, in the prior art, the performance (shape reproducibility and stability) of the gas cluster ion beam varies greatly depending on the accuracy of the component parts and the skill level of the worker performing the assembly.

In addition, in the conventional technology, the mechanical accuracy of the structure is not sufficient and relied on manual adjustment. Therefore, the adjustment time for obtaining the desired performance for the gas cluster ion beam differs depending on the skill level of the operator, and the time is increased. There was a problem to do.
On the other hand, it is conceivable to construct a gas cluster ion beam device with parts with improved machining accuracy, but the reproducibility and stability of the gas cluster ion beam can be achieved only by assembling the parts with improved machining precision. Sex does not improve so much.

  In this case, it is possible to use a precision positioning stage, but the precision positioning stage is expensive, so the cost is high, and since the adjustment mechanism is large, the device itself becomes large. there were.

JP 2006-294317 A

The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide a technique for improving the reproducibility and stability of the shape of a gas cluster ion beam.
Another object of the present invention is to provide a technique capable of easily adjusting the beam axis in a short time regardless of the skill level of the operator.

The present invention made to solve the above problems is a gas cluster ion beam apparatus that ionizes and ejects a gas cluster beam emitted from a nozzle and cut out by a skimmer in an ionization chamber, the nozzle member having the nozzle And a nozzle holding member having a guide surface extending in a direction orthogonal to the beam axis direction of the gas cluster ion beam, the nozzle holding member, the skimmer, and the ionization chamber at predetermined positions. A positioning structure that is integrally assembled in a positioned state, and by moving the nozzle member along the guide surface of the nozzle holding member, it is orthogonal to the beam axis direction of the gas cluster ion beam. Also configured to adjust the position of the nozzle with respect to the direction to It is.
The present invention is also effective when the nozzle member is held by the nozzle holding member via an elastic member and the nozzle member moves against the elastic force of the elastic member. .
The present invention is also effective when the elastic member is made of an elastomer.
In the present invention, it is also effective when the elastic member is constituted by an O-ring.

  In the present invention, the reproducibility and stability of the shape of the gas cluster ion beam can be improved, and the beam axis adjustment operation can be easily performed in a short time regardless of the skill level of the operator.

The schematic diagram which shows the structure of embodiment of the gas cluster ion beam apparatus concerning this invention (A): sectional view showing the nozzle member (b): sectional view showing the nozzle holding member (c): sectional view showing a state in which the nozzle member is mounted on the nozzle holding member Explanatory drawing which shows the example of the method of adjusting the beam axis of the nozzle in this Embodiment (the 1) Explanatory drawing which shows the example of the method of adjusting the beam axis of the nozzle in this Embodiment (the 2) Schematic diagram showing the configuration of a conventional gas cluster ion beam device

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing a configuration of an embodiment of a gas cluster ion beam apparatus according to the present invention.

As shown in FIG. 1, the gas cluster ion beam apparatus 1 of the present embodiment has an integrated positioning structure 10 having a nozzle member 60, a nozzle holding member 70, a skimmer 3, and an ionization chamber 4. doing.
Here, the nozzle member 60, the nozzle holding member 70, and the skimmer 3 are arranged in the first vacuum chamber 12 connected to the first vacuum exhaust system 11, and the ionization chamber 4 is in the second vacuum exhaust system 13. It arrange | positions in the 2nd vacuum chamber 14 connected to.

  The nozzle member 60 has a conical and supersonic type nozzle 61 connected to a gas introduction system (not shown). The noble gas introduced from the gas introduction system is discharged from the nozzle 61 at a high pressure of several atmospheric pressures or more. It is configured to generate a rare gas cluster by being ejected into a vacuum.

  The supersonic jet of the rare gas ejected from the nozzle 61 is converted into a translational motion in the adiabatic expansion process and the temperature is lowered, and the gas atoms (molecules) are several hundred to several thousand by van der Waals force. A cluster of atoms (molecules) is formed, and a gas cluster beam is generated.

The skimmer 3 is arranged on the downstream side in the axial direction in which the noble gas cluster beam travels (hereinafter referred to as “beam axial direction P”).
The skimmer 3 cuts out the central portion of the generated gas cluster beam, and the gas cluster beam cut out by the skimmer 3 is guided to the ionization chamber 4 provided on the downstream side in the beam axis direction P.

A heat filament 40 is provided in the ionization chamber 4.
Thermoelectrons are emitted from the hot filament 40, and the thermoelectrons are accelerated to several hundred volts by the anode grid 41 and irradiated to the gas cluster beam. As a result, the neutral gas cluster beam is ionized by electron impact, and gas cluster ions are emitted. A beam is formed.

In the second vacuum chamber 14, the electrostatic lens unit 5 is provided downstream of the ionization chamber 4 in the beam axis direction P.
The electrostatic lens unit 5 is for accelerating and converging the gas cluster ion beam. Here, a plurality of electrostatic lenses 50 are arranged along the beam axis direction P.
In the present invention, an extraction electrode (not shown) may be provided instead of the electrostatic lens unit 5 to extract the gas cluster ion beam.

In the present embodiment, an aperture 51 is provided on the upstream side in the beam axis direction P of the electrostatic lens 50 of the electrostatic lens unit 5.
The aperture 51 is arranged and configured so that the center of the opening 52 coincides with the center of the electrostatic lens 50.

The positioning structure 10 according to the present embodiment is configured so that a nozzle holding member 70 (to be described later) that holds the nozzle member 60, the skimmer 3, and the ionization chamber 4 are integrally assembled in a state where they are positioned at predetermined positions. It is configured.
Specifically, the nozzle holding member 70, the skimmer 3, and the ionization chamber 4 are configured to be integrally assembled based on a general clearance fit tolerance.

2A is a sectional view showing the nozzle member, FIG. 2B is a sectional view showing the nozzle holding member, and FIG. 2C is a sectional view showing a state in which the nozzle member is mounted on the nozzle holding member. It is.
As shown in FIG. 2A, the nozzle member 60 of the present embodiment has a nozzle 61 formed in an elongated cylindrical shape having an outer diameter d, and is provided integrally on the gas introduction side of the nozzle 61. A flange portion 62 is provided.

On the gas discharge side of the flange portion 62, a guided surface 63 is provided in which a plane extending in a direction orthogonal to the central axis of the nozzle 61, that is, the beam axis M of the gas cluster beam is formed.
A plurality of screw holes 64 extending in parallel with the central axis M of the nozzle 61 are provided in the flange portion 62 of the nozzle member 60.

As shown in FIG. 2B, the nozzle holding member 70 is a cylindrical main body 71 formed with an inner diameter D slightly larger (about 0.02 to 0.4 mm) than the outer diameter d of the nozzle 61. A flange portion 72 is provided at one end portion of the main body portion 71.
On the opposite side of the flange portion 72 of the nozzle holding member 70 from the main body portion 71, a guide surface 73 having a plane extending in a direction orthogonal to the central axis N of the cylinder of the main body portion 71 is provided.

The flange portion 72 of the nozzle holding member 70 is provided with a plurality of position adjustment holes 74 for adjusting the nozzle position. These position adjustment holes 74 are formed at a number and pitch corresponding to the screw holes 64 of the nozzle member 60.
Further, the nozzle holding member 70 is provided with, for example, a circular groove 75 at the end of the main body 71 on the flange 72 side so as to be continuous with the inner peripheral surface 71 a of the main body 71.

In the present embodiment, an O-ring 76 that is an elastic member is attached to the groove 75 of the nozzle holding member 70.
In the case of the present invention, the O-ring 76 may be made of a normal elastomer.

  In this case, in a state where the O-ring 76 is mounted in the groove 75 of the nozzle holding member 70, no positional deviation occurs, the inner diameter s is smaller than the inner diameter D of the main body 71 of the nozzle holding member 70, and A nozzle member 60 having a size slightly smaller than the outer diameter d of the nozzle 61 and allowing the nozzle 61 to be inserted (pressed) is used.

  On the other hand, on the side opposite to the flange portion 72 of the main body portion 71 of the nozzle holding member 70, a cylindrical extension portion 77 is provided integrally with the main body portion 71. A ring-shaped skimmer support 78 is provided.

  The skimmer support 78 is attached in a state where the above-described skimmer 3 is positioned, whereby the central portion of the skimmer 3 and the central portion of the ionization chamber 4 described above are the center of the main body 71 of the nozzle holding member 70. It is located on the axis N.

  As shown in FIG. 2C, in the present embodiment, an O-ring 76 is attached to the groove 75 of the nozzle holding member 70, and the nozzle 61 of the nozzle member 60 is inserted into the O-ring 76 and assembled.

  In this state, the guided surface 63 of the nozzle member 60 is in contact with the guide surface 73 of the nozzle holding member 70. In addition, the outer peripheral surface 61a of the nozzle 61 of the nozzle member 60 and the inner peripheral surface 71a of the main body 71 of the nozzle holding member 70 are brought into contact with each other without being in contact with each other and are stationary.

  Further, as described above, the guided surface 63 of the nozzle member 60 extends in a direction orthogonal to the central axis M of the nozzle 61, and the guide surface 73 of the nozzle holding member 70 extends in a direction orthogonal to the central axis N of the main body 71. Therefore, in a state where the nozzle member 60 is held by the nozzle holding member 70, the central axis M of the nozzle 61 of the nozzle member 60 and the central axis N of the main body 71 of the nozzle holding member 70 are parallel.

  With the above configuration, in the present embodiment, when the nozzle holding member 70, the skimmer 3, and the ionization chamber 4 are assembled to the positioning structure 10, the central axis M of the nozzle 61 of the nozzle member 60 and the main body of the nozzle holding member 70. The nozzle member 60 can be moved in a direction orthogonal to the central axis N of the main body 71 of the nozzle holding member 70, that is, the beam axis direction P, while maintaining the central axis N of the portion 71 in parallel.

  Here, in the present embodiment, since the O-ring 76 is interposed between the nozzle member 60 and the nozzle holding member 70, the nozzle member 60 is moved against the elastic force of the O-ring 76. However, when the external force is released from the nozzle member 60 after the nozzle member 60 is moved, the nozzle member 60 returns to the original position by the elastic force of the O-ring 76.

  In the present embodiment, when the nozzle member 60 is moved in a direction orthogonal to the beam axis direction P, the screw hole 64 of the flange portion 62 of the nozzle member 60 is replaced with the flange portion of the nozzle holding member 70. These positions and dimensions are set so as not to deviate from the range of the 72 position adjustment holes 74.

3 and 4 show an example of a method for adjusting the beam axis of the nozzle in the present embodiment.
In the present embodiment having the above-described configuration, as shown in FIG. 3, the beam axis of the nozzle 61 is assembled with the nozzle member 60, the nozzle holding member 70, the skimmer 3, and the ionization chamber 4 assembled to the positioning structure 10. Make adjustments.

Here, a bolt 80 for fixing the nozzle member 60 to the nozzle holding member 70 is mounted in the screw hole 64 of the nozzle member 60 without being fastened.
Further, the center of the opening 52 of the aperture 51 of the electrostatic lens unit 5 is aligned with the ionization chamber 4 using a jig (not shown).

  As described above, in the positioning structure 10, the nozzle holding member 70, the skimmer 3, and the ionization chamber 4 are assembled in a positioned state, so that the ionization chamber 4 and the electrostatic lens unit 5 By performing alignment with the center of the opening 52 of the aperture 51, the nozzle holding member 70, the skimmer 3, the ionization chamber 4, and the electrostatic lens unit 5 are relatively positioned.

  In this state, the laser beam 90 is irradiated from the upstream side in the beam axis direction P of the nozzle member 60, and this laser beam 90 is irradiated by the CCD camera 91 disposed on the downstream side in the beam axis direction P with respect to the electrostatic lens unit 5. To detect.

  In this case, by storing the position coordinates of the optical axis of the laser light 90 in advance, the optical axis of the laser light 90 detected by the CCD camera 91 is a direction orthogonal to the beam axis direction P from the position coordinates. It is possible to detect how much it is shifted in the direction perpendicular to the beam axis.

  Here, since the nozzle holding member 70, the skimmer 3, the ionization chamber 4, and the electrostatic lens unit 5 are already positioned, the positional deviation of the laser light 90 in the direction perpendicular to the beam axis is attached to the nozzle holding member 70. This corresponds to the displacement of the nozzle member 60 in the direction perpendicular to the beam axis.

  Therefore, for example, the nozzle member 60 is moved along the guide surface 73 of the nozzle holding member 70 against the elastic force of the O-ring 76 in the direction orthogonal to the beam axis. Then, the nozzle member 60 is temporarily fixed to the nozzle holding member 70 by fastening the nut 81 to the bolt 80 to some extent at the moved position (see FIG. 4).

In this state, the laser beam 90 is irradiated again from the upstream side of the nozzle member 60 in the beam axis direction P, and the laser beam 90 is detected by the CCD camera 91.
If the positional deviation of the optical axis of the laser beam 90 detected by the CCD camera 91 in the direction perpendicular to the beam axis is within a predetermined range, it is determined that the positioning of the nozzle member 60 has been completed and the bolt 80 and the nut 81 is completely fastened, and the position adjustment operation of the nozzle member 60 is completed.

On the other hand, when the positional deviation of the optical axis of the laser beam 90 detected by the CCD camera 91 in the direction perpendicular to the beam axis exceeds a predetermined range, the bolt 80 and the nut 81 are loosened.
As a result, the external force applied to the nozzle member 60 is released, and the nozzle member 60 returns to the original position by the elastic force of the O-ring 76. Therefore, the nozzle member 60 is moved again with reference to this position. And as above-mentioned, the bolt 80 and the nut 81 are temporarily fastened, and the irradiation operation | work of the laser beam 90 and the detection operation of a position shift are performed.
This operation is repeated until the positional deviation of the optical axis of the laser beam 90 detected by the CCD camera 91 in the direction perpendicular to the beam axis falls within a predetermined range.

  As described above, in the present embodiment, the nozzle holding member 70, the skimmer 3, and the positioning structure 10 that is integrally assembled in a state where the ionization chamber 4 is positioned at a predetermined position, Since the nozzle member 60 is moved along the guide surface 73 of the nozzle holding member 70, the position of the nozzle 61 is adjusted with respect to the direction orthogonal to the beam axis P of the gas cluster ion beam. The beam axis of the gas cluster beam on the source side can be accurately aligned with the beam axis of the gas cluster ion beam on the ion transport side, thereby improving the reproducibility and stability of the shape of the gas cluster ion beam. be able to.

Further, according to the present embodiment, the beam axis adjustment operation can be easily performed in a short time regardless of the skill level of the operator.
In particular, in the present embodiment, since the O-ring 76 that is an elastic member is interposed between the nozzle member 60 and the nozzle holding member 70, the nozzle member 60 is moved against the elastic force of the O-ring 76. The nozzle member 60 is returned to the original position by the elastic force of the O-ring 76 by releasing the external force to the nozzle member 60 later.

As a result, the position of the nozzle member 60 can be adjusted again from the returned position, and movement adjustment to the target position can be easily performed.
Furthermore, according to the present embodiment, by using the O-ring 76, it is possible to achieve downsizing of the apparatus without requiring a large adjustment mechanism.

The present invention is not limited to the above-described embodiment, and various changes can be made.
For example, various members other than the O-ring can be used as the elastic member.
However, if an O-ring is used, the nozzle member can be stably held using existing parts, and the cost is low.
Further, the shapes of the nozzle member and the nozzle holding member are not limited to the above embodiment, and various changes can be made.

DESCRIPTION OF SYMBOLS 1 ... Gas cluster ion beam apparatus 3 ... Skimmer 4 ... Ionization chamber 5 ... Electrostatic lens unit 10 ... Positioning structure 12 ... 1st vacuum chamber 14 ... 2nd vacuum chamber 60 ... Nozzle Member 61 ... Nozzle 63 ... Guided surface 70 ... Nozzle holding member 73 ... Guide surface 76 ... O-ring (elastic member)

Claims (4)

A gas cluster ion beam device that ionizes and ejects a gas cluster beam emitted from a nozzle and cut out by a skimmer in an ionization chamber,
A nozzle holding member having a guide surface that holds a nozzle member having the nozzle and extends in a direction orthogonal to a beam axis direction of the gas cluster ion beam;
The nozzle holding member, the skimmer, and a positioning structure that is integrally assembled in a state where the ionization chamber is positioned at a predetermined position;
A gas cluster configured to adjust the position of the nozzle with respect to a direction orthogonal to a beam axis direction of the gas cluster ion beam by moving the nozzle member along a guide surface of the nozzle holding member. Ion beam device.   The gas cluster ion beam apparatus according to claim 1, wherein the nozzle member is held by the nozzle holding member via an elastic member, and the nozzle member moves against an elastic force of the elastic member.   The gas cluster ion beam apparatus according to claim 2, wherein the elastic member is made of an elastomer.   The gas cluster ion beam apparatus according to claim 3, wherein the elastic member is configured by an O-ring.

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