JP2010225442A - Gas cluster ion beam irradiation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adjust in a vacuum so as to restrain a nozzle from moving, to obtain cluster ion beams of a stable and appropriate size distribution, and take a plenty of cluster ion beam current. <P>SOLUTION: A skimmer 7 arranged between a cluster generating chamber 1 and a beam control part 2 is loaded through a plate 8 on an XY stage 10a, and a position of the skimmer 7 is adjusted with micrometers 10b, 10c. The micrometers 10b, 10c are arranged exposed outside a vacuum chamber 40, so that they 10b, 10c are operated with a vacuum degree of the vacuum chamber 40 retained. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a gas cluster ion beam irradiation apparatus that performs processing and surface formation with a gas cluster ion beam.

  In recent years, attention has been focused on gas cluster ion beam processing that realizes irradiation energy at a level of 100 eV or less per atom, which cannot be achieved by an ion beam extracted from plasma. A gas cluster ion beam is an ion beam that is obtained by adiabatic expansion of high-pressure gas from a nozzle under vacuum, ionization by irradiating electrons to the clustered particles by supercooling, and acceleration / deceleration by an electric field. .

  This gas cluster ion beam irradiation apparatus for irradiating a target with an ion beam includes a vacuum chamber, which is divided into a cluster generation chamber, a beam control chamber, and an irradiation chamber, each of which is appropriately vacuumed by a vacuum pump. Depressurized every time. Nozzles are arranged in the cluster generation chamber, and a cluster flow is generated by adiabatic expansion of gas ejected from the nozzles to the cluster generation chamber. A skimmer is disposed in the vacuum chamber, and a part of the cluster flow is guided to the ionization chamber in the beam control chamber. In the ionization chamber, for example, an electron source such as a filament that generates thermoelectrons and an anode electrode that attracts electrons are arranged. Then, electrons generated from the electron source collide with the cluster flow, and some atoms or molecules constituting the cluster are positively ionized by electron impact to generate a cluster ion flow. The cluster ion beam extracted by the extraction electrode passes through an electrode group composed of a plurality of annular electrodes having different voltages, and the acceleration of the beam and the convergence or divergence of the beam are controlled by this electrode group. The cluster ion beam that has passed through the electrode group is bent in the orbit of monomer ions and small cluster ions by a magnetic field by a mass separator. Then, an appropriately sized cluster is selected by the aperture and irradiated to the substrate placed in the irradiation chamber.

  In this type of gas cluster ion beam irradiation apparatus, in order to shorten the processing time for etching, film formation, doping, etc., it is required to increase the processing speed, such as improving the etching rate and film forming speed. Since the speed of this process is proportional to the amount of cluster ion beam to be irradiated, it is necessary to increase the amount of beam in order to speed up the process, and improvement and effective utilization of cluster generation is required.

  By the way, the three-dimensional velocity distribution of the cluster flow generated by the adiabatic expansion from the nozzle is the smallest at the central portion of the cluster flow and becomes larger as the distance from the center increases. Low-velocity atoms (molecules) in the velocity distribution have a small energy difference, so they are likely to bond with a small force during collision and cluster. Therefore, the central portion of the cluster flow has the highest cluster density, and becomes lower as the distance from the center increases. Further, since the higher the density, the higher the probability of collision of atoms (molecules), the center portion of the cluster flow becomes larger in both the amount (namely, number) and size of the clusters. Therefore, the alignment of the center of the cluster flow and the skimmer is very important.

  However, the center of the cluster flow may not always coincide with the mechanical center due to a mechanical manufacturing error. In other words, even if the nozzle and the skimmer are arranged so that the radial center of the nozzle outlet coincides with the radial center of the skimmer aperture, the nozzle or skimmer center may not be aligned due to the manufacturing error of the nozzle or skimmer. In some cases, it does not coincide with the center of the cluster flow. Therefore, in order to efficiently use the generated cluster, a method has been proposed in which an adjustment mechanism is provided in the nozzle, the nozzle is aligned with the aperture of the skimmer, and the ionization chamber opening is aligned (see Patent Document 1). ).

US Pat. No. 6,486,478

  However, since a large amount of gas is introduced into the cluster generation chamber for cluster generation, a high exhaust capacity is required, and the cluster generation chamber of the exhaust port and the vacuum chamber must be enlarged due to the conductance of the exhaust path. I must. For this reason, in the conventional configuration, the nozzle including the adjusting mechanism is long, and the radial rigidity of the nozzle is weak. If the gas ejection direction is deviated from the nozzle axis when the gas is flowed in such a configuration, a force is applied to the nozzle in the radial direction, and the nozzle may vibrate. The vibration disturbed the cluster flow, and the density of the cluster passing through the skimmer fluctuated, resulting in fluctuations in the size distribution and current of the cluster ion beam.

  In the above conventional configuration, since the gas supply pressure to the nozzle is high, the gas supply pipe should be fixed in principle. When adjusting the position of the nozzle, it is necessary to move the connection part with the gas supply pipe at the same time. is there. Therefore, there is a problem that the nozzle may move due to a creep phenomenon even if the stress is relieved.

  Therefore, an object of the present invention is to provide a gas cluster ion beam that can be adjusted in a vacuum so as to obtain a cluster ion beam having a stable and appropriate size distribution and to obtain a large amount of cluster ion beam current while suppressing the movement of the nozzle. It is to provide an irradiation apparatus.

  The present invention is a gas cluster ion beam irradiation apparatus that ionizes and accelerates a cluster at an ionization unit, and irradiates the target with a cluster. A skimmer arranged opposite to the nozzle and passing a cluster flow to the ionization unit, and an adjustment mechanism for adjusting the position of the skimmer relative to the nozzle in a state where the vacuum chamber is sealed. Is.

  According to the present invention, since the position of the skimmer is adjusted, it is not necessary to provide a mechanism for moving the nozzle, and the movement of the nozzle can be suppressed. Further, by adjusting the position of the skimmer while maintaining the degree of vacuum in the vacuum chamber, the portion having the highest cluster density can be taken into the ionization portion, and the cluster ion beam current can be increased. Further, by adjusting the position of the skimmer while maintaining the vacuum degree of the vacuum chamber, it is possible to adjust the cluster size suitable for irradiation. Furthermore, since it is not necessary to open the vacuum chamber to the atmosphere each time the position of the skimmer is adjusted, the work for adjusting the position of the skimmer can be shortened.

It is explanatory drawing which shows schematic structure of the gas cluster ion beam irradiation apparatus which concerns on 1st Embodiment of this invention. It is explanatory drawing which shows schematic structure of the gas cluster ion beam irradiation apparatus which concerns on 2nd Embodiment of this invention, (a) is explanatory drawing which shows the principal part of an apparatus, (b) is the parallel displacement part of an adjustment mechanism. It is a schematic perspective view shown. It is explanatory drawing which shows schematic structure of the gas cluster ion beam irradiation apparatus which concerns on 3rd Embodiment of this invention. It is explanatory drawing which shows schematic structure of the gas cluster ion beam irradiation apparatus which concerns on 4th Embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is an explanatory diagram showing a schematic configuration of a gas cluster ion beam irradiation apparatus according to the first embodiment of the present invention. The gas cluster ion beam irradiation apparatus 100 includes a vacuum chamber 40 including two vacuum vessels 41 and 42. Of the two vacuum vessels 41 and 42 of the vacuum chamber 40, the first vacuum vessel 41 is formed with the cluster generation chamber 1, and the first vacuum vessel 41 and the second vacuum vessel 42 are separated from each other. The beam control chamber 2 and the irradiation chamber 3 are formed separately. The vacuum pumps 4, 5, and 6 are connected to the chambers 1, 2, and 3, and the pressure is reduced to an appropriate degree of vacuum.

In the cluster generation chamber 1, a nozzle 14 having an appropriate shape such as a conical type or a Laval type is fixed. A gas (for example, 6 atm Ar gas) supplied from a supply source (not shown) is controlled in pressure by a regulator (not shown), supplied to the stagnation chamber 13 via the gas supply pipe 12, and from the nozzle 14 into the vacuum chamber. Is ejected into the cluster generation chamber 1. The jetted gas becomes a jet composed of gas atoms or molecules that move at the supersonic speed in the same direction due to adiabatic expansion. From this gas jet, clusters of several to tens of thousands of atoms or molecules are generated by van der Waals force. As the source gas, in addition to Ar, gas such as CO ₂ , O ₂ , N ₂ , NO, NO ₂ , NH ₃ , SF ₆ , CF ₄ , or He is mixed to facilitate the generation of clusters thereof. Gas is available. Here, the cluster accelerated by the acceleration voltage is expressed as “beam”, and the other is expressed as “flow”.

  The three-dimensional velocity distribution of this jet flow is the smallest at the central portion of the gas flow ejected from the jet outlet 14a of the nozzle 14, and becomes larger as the distance from the center is increased in the radial direction. The lower the gas velocity, the lower the temperature of the gas, so the closer to the center, the amount of clusters (that is, the number of clusters that pass through the unit area per unit time, in other words, density) and the cluster size (configures individual clusters). Number of atoms or molecules) to be increased.

  Further, in the cluster generation chamber 1, a skimmer 7 having a small-diameter aperture formed in order to prevent a shock wave is disposed to face the nozzle 14, and a part of the cluster flow is used as an ionization unit in the beam control chamber 2. The ionization chamber 16 is passed through. A voltage is applied to the ionization chamber 16, and for example, an electron source such as a filament that generates thermoelectrons and an anode electrode that attracts electrons are disposed. Then, electrons generated from the electron source efficiently collide with the cluster flow, and some atoms or molecules constituting the cluster are positively ionized by electron impact to generate a cluster ion flow.

  The extraction electrode 18 is applied to a ground potential lower than the potential of the ionization chamber 16 and extracts the cluster ion beam by an electric field generated by the potential difference. The cluster ion beam extracted by the extraction electrode 18 passes through an annular electrode group 19 composed of a plurality of annular electrodes having different voltages. The annular electrode group 19 accelerates the beam and converges or diverges the beam (beam diameter). Is controlled.

  A mass separator 20 and an aperture 21 are disposed downstream of the annular electrode group 19 in the traveling direction of the cluster beam. In the mass separator 20, in order to remove monomers and clusters having a small mass such as monomer ions and cluster ions having a small size, the orbits of the ions of monomers and clusters having a small mass are greatly bent by the generation of a magnetic field. The aperture 21 is adjusted in opening size, and an appropriate size cluster is selected by the aperture 21. A cluster ion beam having an appropriate size distribution is guided to the irradiation chamber 3 by the mass separator 20 and the aperture 21. In the irradiation chamber 3, an XYZ stage 26 and a substrate 23 that is a target mounted on the XYZ stage 26 are disposed, and the substrate 23 is irradiated with a cluster ion beam that has passed through the aperture 21.

  When the substrate 23 is an insulator and charges are accumulated, by appropriately operating the neutralizer 25, the cluster can be neutralized to prevent changes in the beam trajectory and irradiation energy due to the repulsive force, thereby stabilizing the beam. Then, the substrate 23 can be irradiated. In order to prevent skimmer destruction due to a pressure difference between the two chambers that occurs at the start of exhaust, venting (when the atmosphere is open), etc., bypass pipes and valves (not shown) are installed between the two chambers.

  By the way, in this 1st Embodiment, the gas cluster ion beam irradiation apparatus 100 is provided with the adjustment mechanism 50 which adjusts the position of the skimmer 7 with respect to the nozzle 14 with the vacuum chamber 40 sealed. Thus, since the nozzle 14 is fixed to the vacuum chamber 40 (cluster generation chamber 1) and the position of the skimmer 7 is adjusted by the adjustment mechanism 50, it is not necessary to provide a mechanism for moving the nozzle 14, and the nozzle 14 Can be prevented from moving.

  The adjusting mechanism 50 includes an in-plane moving unit 10 that moves the skimmer 7 in a plane (arrow XY direction) whose normal direction is the ejection direction (arrow Z direction) of the cluster flow ejected from the nozzle 14. . The in-plane moving unit 10 is an XY stage 10a that supports the skimmer 7 through the plate 8 so as to be movable in-plane with the skimmer 7 and two micrometers that are XY stage operating units that move the XY stage 10a. 10b and 10c.

  More specifically, the XY stage 10a has an opening at the center of the stage, and the plate 8 is fixed. In the plate 8, an opening is formed in the center of the plate and the skimmer 7 is fixed. An opening is formed in the wall 41 a of the first vacuum container 41, and the XY stage 10 a is fixed to the outer surface of the first vacuum container 41 with the skimmer 7 facing the opening of the first vacuum container 41. ing. An opening is formed in the wall portion 42a of the second vacuum vessel 42, and the opening of the first vacuum vessel 41 and the second vacuum vessel are connected so that the cluster generation chamber 1 and the beam control chamber 2 communicate with each other. The opening part of 42 is connected by the bellows 9. The plate 8 fixed to the XY stage 10a can move together with the skimmer 7 in each of two axes (for example, ± 5 mm) in the depth direction (arrow X direction) and the vertical direction (arrow Y direction) in the figure. That is, the skimmer 7 can be moved in the direction of the arrow XY within a plane in which the ejection direction of the cluster flow is the normal direction with respect to the ejection port 14a of the nozzle 14. The micrometers 10b and 10c are of a manual type and are exposed to the outside of the vacuum chamber 40. Thereby, in the operation | work which adjusts the position of the skimmer 7, it can carry out in the airtight state, without opening the vacuum chamber 40 to air | atmosphere.

  In the first embodiment, the gas cluster ion beam irradiation apparatus 100 includes a measuring device (measuring unit) 30 that measures a physical quantity used when the position of the skimmer 7 is adjusted by the adjusting mechanism 50.

  Here, since the cluster flow 15 that has passed through the skimmer 7 has a density distribution, the amount of clusters that enter the beam control chamber 2 varies depending on the position of the skimmer 7. It is difficult to directly measure the amount of clusters that have passed through the skimmer 7, and it is necessary to measure a physical quantity corresponding to this.

  Therefore, the measuring apparatus 30 of the first embodiment includes a vacuum gauge 32 that measures pressure as a cluster amount measuring unit that measures a physical quantity corresponding to the amount of clusters that have passed through the skimmer 7. The vacuum gauge 32 is a dynamic pressure gauge having a vacuum-sealed diaphragm type pressure gauge, a piezoelectric gauge, or the like, and is provided in the beam control chamber 2 so that the display unit is exposed from the second vacuum vessel 42. Yes. In each of the rooms 1 and 3, vacuum gauges 31 and 33 having the same configuration as the vacuum gauge 32 are provided.

  Here, most of the gas that has passed through the skimmer 7 is a cluster. The pressure (degree of vacuum) in the beam control chamber 2 and the amount of clusters are correlated with each other under a constant gas supply amount and exhaust amount from the nozzle 14. In particular, under a constant speed and a constant cluster size, the pressure in the beam control chamber 2 and the amount of clusters are proportional. That is, the pressure measurement by the vacuum gauge 32 is less accurate than the direct measurement of the amount of clusters, but a simple configuration that only attaches the vacuum gauge 32 may be used, and the amount of clusters is relatively large or small. If it can be evaluated, the position of the skimmer 7 can be adjusted. Therefore, the amount of clusters can be evaluated by measuring the pressure of the beam control chamber 2 with the vacuum gauge 32 as a physical quantity.

  The amount of clusters entering the beam control chamber 2 can be maximized by adjusting the position of the XY stage 10a so that the pressure of the vacuum gauge 32 provided in the beam control chamber 2 becomes the highest. As a result, a portion having the highest cluster density in the cluster flow ejected from the nozzle 14 can be taken into the ionization chamber 16. Thus, by evaluating the cluster amount with the vacuum gauge 32, the entire cluster flow can be evaluated, so that the position of the skimmer 7 can be adjusted so that the cluster flow enters the ionization chamber 16 most.

  Therefore, by adjusting the position of the skimmer 7 with the vacuum degree of the vacuum chamber 40 maintained, a portion having the highest cluster density can be taken into the ionization chamber 16 and the cluster ion beam current can be increased. Further, the center in the radial direction of the cluster flow where the amount of the cluster is maximum is also the portion where the size of the cluster is maximum. Therefore, the cluster size suitable for irradiation can be adjusted by adjusting the position of the skimmer 7 to a position where the amount of clusters is maximized. Furthermore, since it is not necessary to open the vacuum chamber 40 to the atmosphere each time the position of the skimmer 7 is adjusted, the work of adjusting the position of the skimmer 7 can be shortened.

[Second Embodiment]
Next, the gas cluster ion beam irradiation apparatus of 2nd Embodiment is demonstrated. Note that in the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. As shown in FIGS. 2A and 2B, the adjustment mechanism 50 </ b> A of the second embodiment is configured so that the in-plane moving unit 10 and the skimmer 4 are ejected from the nozzle 14 with respect to the ejection direction of the cluster flow. And a parallel moving part 11 for moving in the parallel direction (arrow Z direction). The translation unit 11 includes a Z stage 11a that can move in the direction of arrow Z integrally with the skimmer 7, and two micrometers 11b that are arranged diagonally to the Z stage 11a as a Z stage operation unit that moves the Z stage 11a. And have. Moreover, the translation part 11 has the two linear bush 11c and the linear guide 11d which are arrange | positioned diagonally.

  The skimmer 7 is fixed to the plate 8, the plate 8 is fixed to the XY stage 10a, the XY stage 10a is fixed to the Z stage 11a, and the Z stage 11a has the cluster generation chamber 1 formed therein. The first vacuum vessel 41 is fixed. Thereby, it is possible to adjust the three axes including the ejection direction of the cluster flow. The Z stage 11a is movable in the arrow Z direction within a movable range of ± 3 mm, for example.

  The micrometer 11 b is of a manual type and is disposed so as to be exposed to the outside of the first vacuum container 41 of the vacuum chamber 40. Thereby, in the operation | work which adjusts the position of the skimmer 7, it can carry out in the airtight state, without opening the vacuum chamber 40 to air | atmosphere. Since the optimum position for the ejection direction of the cluster flow differs depending on the gas type and pressure, the operator looks at the micrometers 10b and 10c (see FIG. 1) while observing the degree of vacuum in the beam control chamber 2 (pressure indicated by the vacuum gauge 32). ) And the micrometer 11b can be operated to adjust the three axes. By this operation, the cluster can be efficiently introduced into the ionization chamber 16 (FIG. 1). The assembling order of the XY stage 10a and the Z stage 11a can be determined according to the stage mountable weight and usability.

  Here, when the interval between the nozzle 14 and the skimmer 7 is too wide, a shock wave is generated when another particle having a different velocity collides with a particle including a cluster, and a large number of cluster particles are decomposed by the shock wave. As a result, a large amount of monomer is generated. On the other hand, when the distance between the nozzle 14 and the skimmer 7 is too narrow, particles (components that increase the temperature) such as monomers far from the center of the cluster flow or clusters having a small mass pass through the skimmer 7 and the particles. Diffuses into the beam control chamber 2 and becomes floating molecules. When a cluster collides with this floating molecule, the traveling direction of the cluster changes.

  Therefore, by adjusting the position of the skimmer 7 in the direction of the arrow Z parallel to the cluster flow ejected from the nozzle 14, it is possible to suppress the generation of shock waves, and the skimmer 7 can remove the component that raises the temperature. Thereby, many cluster flows with uniform directions can be taken out, and the size distribution and current of the cluster ion beam can be improved.

[Third Embodiment]
Next, the gas cluster ion beam irradiation apparatus of 3rd Embodiment is demonstrated. Note that in the third embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals and description thereof is omitted. In the first and second embodiments, the case where the vacuum gauge 32 is a mechanical pressure gauge such as a vacuum-sealed diaphragm type pressure gauge or a piezo gauge has been described. However, in the third embodiment, the vacuum gauge is an ion A case where a gauge is used will be described. The ion gauge 17 shown in FIG. 3 measures the ion current by ionizing the cluster, and includes, for example, a filament from which electrons jump out, a grid, and a collector that collects ions. The ion gauge 17 is movable, and is arranged so as to be movable between a cluster path in the beam control chamber 2 and a position deviating from the path. Further, the ion gauge 17 is arranged on the downstream side of the skimmer 7 in the cluster flow ejection direction (immediately after the skimmer 7), and the non-ionized cluster is irradiated. That is, in the third embodiment, the ion gauge 17 measures a current as a physical quantity corresponding to the amount of clusters that have passed through the skimmer 7. And the output of the ion gauge 17 changes by moving the XY stage 10a and the Z stage 11a and adjusting the position of the skimmer 7.

  Thus, since the cluster flow is directly applied to the ion gauge 17, measurement with higher sensitivity than the vacuum gauge 32 (FIG. 1) can be performed, and the accuracy of position adjustment of the skimmer 7 is improved. Further, by removing the ion gauge 17 from the path of the cluster flow, it is possible to prevent the cluster from colliding with the ion gauge 17 when the substrate 23 is irradiated with the cluster, so that the cluster is destroyed and the ion gauge 17 is contaminated. Can be prevented.

[Fourth Embodiment]
Next, the gas cluster ion beam irradiation apparatus of 4th Embodiment is demonstrated. Note that in the fourth embodiment, identical symbols are assigned to configurations identical to those in the first embodiment and descriptions thereof are omitted. In the first to third embodiments, the case has been described in which the measuring device includes a vacuum gauge that measures a physical quantity corresponding to the amount of clusters that have passed through the skimmer. On the other hand, in the fourth embodiment, as shown in FIG. 4, the case where the measuring apparatus includes a measuring device 35 that is a cluster size measuring unit that measures a physical quantity corresponding to the size of the cluster that has passed through the skimmer is described. To do.

  The measuring device 35 has a chopper electrode 22 and a Faraday cup 24 as a detector for detecting current, and measures the flight time of the cluster. The chopper electrode 22 is provided in the beam control chamber 2 on the downstream side in the ejection direction of the cluster of the annular electrode group 19, deflects the cluster beam, and releases the deflection in a pulse manner, so that a pulse-like straight beam is generated. Obtainable. The Faraday cup 24 is provided in the irradiation chamber 3 and is irradiated with a pulsed straight beam.

  Since individual cluster ion particles in the cluster ion beam have the energy of the potential of the ionization chamber 16 as kinetic energy, the speed varies depending on the size of the cluster. Therefore, the time for the pulsed straight beam to reach the Faraday cup 24 from the chopper electrode 22 is longer as the cluster size is larger. For example, when the distance between the chopper electrode 22 and the Faraday cup 24 is 40 cm and the potential of the ionization chamber 16 is 20 kV, the monomer ion is about 18 μsec. On the other hand, the cluster consisting of Ar100 atoms takes about 183 μsec, and the cluster consisting of Ar1000 atoms takes about 580 μsec.

  Therefore, the cluster size can be evaluated by observing the ionic current detected by the Faraday cup 24 with an oscilloscope (not shown). The chopper electrode 22 is also movable and can be removed from the path of the cluster ion beam so as not to interfere with the beam optical path.

  Further, by moving the Faraday cup 24 in a plane in which the beam traveling direction is a normal direction, the cluster size distribution in the plane in which the Faraday cup 24 moves can be evaluated. Therefore, by obtaining the position of the substrate 23 and the scanning range of the XYZ stage 26 from the position of the aperture 21 and the position of the Faraday cup 24, the size distribution of the cluster ion beam to be irradiated can be made desired.

  Here, as the cluster flow moves away from the center in the radial direction, the cluster size decreases. Therefore, if the skimmer 7 is moved in the plane (in the direction of the arrow XY) with the cluster flow as the normal direction while measuring the cluster size, the cluster size distribution in the radial direction of the cluster flow can be found. That is, the cluster flow has a cluster size distribution in the radial direction, and the aperture diameter of the skimmer 7 is smaller than the diameter of the cluster flow. Therefore, when the skimmer 7 is moved, the cluster size distribution is evaluated at each position. be able to. Thus, by evaluating the cluster size after passing through the skimmer, the skimmer can be adjusted where the clusters are well generated.

  Further, it is possible to select a skimmer 7 having an aperture that can pass through a region in which a necessary cluster size is distributed, and it is not necessary to perform trial and error, and the skimmer 7 is disposed only by opening the vacuum chamber 40 to the atmosphere once. be able to. By selecting and arranging the optimum skimmer 7, the number of clusters that can pass through the skimmer 7 and transport to the ionization chamber 16 is remarkably increased, and the cluster generation capability of the apparatus can be maximized.

  In the cluster ion beam, the energy amount per atom is a basic parameter of the irradiation effect. Therefore, in order to efficiently obtain a cluster ion beam having an appropriate size distribution according to the acceleration voltage, gas type, and desired action, the capacity of the apparatus is maximized by adjusting the position of the skimmer 7 in addition to the above parameters. Can be pulled out.

  In addition to the time-of-flight method, there is a decelerating electrode method as an ion beam particle evaluation method, which is described in detail in the literature ("Charged Particle Beam Engineering" written by Junzo Ishikawa, issued by Corona 2001) It is possible to evaluate the cluster size by each method. In particular, as described above, when using the so-called time-of-flight method that measures the flight time to the detector when the same kinetic energy is applied and calculates the mass, the cluster size distribution is obtained as a measurement result in real time. The adjustment accuracy and time are very effective.

  In addition, although this invention was demonstrated based on the said embodiment, this invention is not limited to this. In the first to fifth embodiments, the case where the micrometer for moving the XY stage is manually operated has been described. However, the present invention is not limited to this, and the operation may be performed using an electric motor or the like. Similarly, in the second to fifth embodiments, the case where the micrometer for moving the Z stage is manually operated has been described. However, the present invention is not limited to this. Also good. That is, the operation amount of each micrometer may be controlled by the control device based on the measurement result of the measurement device so that the cluster amount and the cluster size are maximized.

  In the first embodiment, the measurement device is the vacuum gauge 32 and the vacuum gauge 32 is directly read. However, the measurement device ionizes the cluster and measures the ion current with the Faraday cup or the laser interference. A device that measures ion current with a meter may be used. Also by this, the cluster amount can be evaluated.

  In the fifth embodiment, the case where the detector for detecting current is the Faraday cup 24 has been described. However, the present invention is not limited to this, and the detector may be an electron multiplier, a scintillator, or the like. Any detector may be used as long as the ion current can be detected.

  Moreover, in the said 1st-4th embodiment, a measuring apparatus has a vacuum gauge as a cluster amount measurement part, and the said 5th Embodiment demonstrates the case where a measuring apparatus has a measuring device as a cluster size measurement part. However, the present invention is not limited to this. The measurement apparatus may include a cluster amount measurement unit and a cluster size measurement unit.

7 Skimmer 14 Nozzle 16 Ionization chamber 40 Vacuum chamber 50, 50A Adjustment mechanism 100 Gas cluster ion beam irradiation device

Claims (10)

In a gas cluster ion beam irradiation device that ionizes and accelerates the cluster at the ionization unit and irradiates the target with the cluster,
A nozzle that injects gas into the vacuum chamber and adiabatically expands to generate clusters;
A skimmer disposed opposite the nozzle and passing a cluster stream through the ionization section;
A gas cluster ion beam irradiation apparatus comprising: an adjustment mechanism that adjusts a position of the skimmer with respect to the nozzle while the vacuum chamber is sealed.   2. The gas cluster ion according to claim 1, wherein the adjustment mechanism includes an in-plane moving unit that moves the skimmer in a plane whose normal direction is an ejection direction of the cluster flow ejected from the nozzle. Beam irradiation device.   The in-plane moving unit includes an XY stage that can move in the plane integrally with the skimmer, and an XY stage operating unit that moves the XY stage. The XY stage operating unit is connected to the vacuum chamber. The gas cluster ion beam irradiation apparatus according to claim 2, wherein the gas cluster ion beam irradiation apparatus is disposed so as to be exposed to the outside.   The said adjustment mechanism has a translation part which moves the said skimmer in the direction parallel to the ejection direction of the cluster flow ejected from the said nozzle, The Claim 1 characterized by the above-mentioned. Gas cluster ion beam irradiation device.   The parallel movement unit includes a Z stage that can move in the parallel direction integrally with the skimmer, and a Z stage operation unit that moves the Z stage, and the Z stage operation unit is located outside the vacuum chamber. The gas cluster ion beam irradiation apparatus according to claim 4, wherein the gas cluster ion beam irradiation apparatus is disposed so as to be exposed to the surface.   The gas cluster ion beam irradiation apparatus according to claim 1, further comprising a measurement unit that measures a physical quantity used when adjusting the position of the skimmer by the adjustment mechanism.   The gas cluster ion beam irradiation apparatus according to claim 6, wherein the measurement unit includes a cluster amount measurement unit that measures a physical quantity corresponding to the amount of clusters that have passed through the skimmer.   The gas cluster ion beam irradiation apparatus according to claim 7, wherein the cluster amount measuring unit is a vacuum gauge.   9. The gas cluster ion beam irradiation apparatus according to claim 6, wherein the measurement unit includes a cluster size measurement unit that measures a physical quantity corresponding to the size of the cluster that has passed through the skimmer. .   The gas cluster ion beam irradiation apparatus according to claim 9, wherein the cluster size measuring unit is a measuring device that measures a flight time of the cluster.

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