Gas cluster ion beam device

Abstract

Provided is a GCIB device capable of changing the energy of ions to be emitted without changing: an extraction electrode arrangement optimized at a specific voltage; an electrode arrangement of a GCIB device having a permanent magnet type magnet for efficiently removing monovalent monomer ions using the voltage; or the magnetic field intensity of the permanent magnet. In addition to the first high-voltage power supply (22a) to the third high-voltage power supply (22c), the GCIB device is also provided with another high-voltage power supply (22d) that generates a positive high voltage or a negative high voltage, and another high-voltage application circuit (27). And another high-voltage application circuit (27) that applies another positive high voltage or negative high voltage from the high-voltage power supply (22d) to the ground electrode portion of the extraction electrode (7) and the ground electrode portions of the electrostatic lenses (9a, 9b).

Description

Technical Field

[0001] The invention relates to a gas cluster ion beam device. Background Art

[0002] Patent document 1 and non-patent document 1 disclose a conventional gas cluster ion beam device (hereinafter sometimes referred to as a GCIB device), in which a gas cluster beam is ionized by electron impact in an ion generator to produce gas cluster ions, and the gas cluster ions are extracted from the ion generator as a beam using an extraction electrode, transported, and irradiated onto a substrate.

[0003] Related technical literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent 6,632,937 (December 20, 2019)

[0006] Non-patent literature

[0007] Non-patent document 1: Materials processing by cluster ion beams (Isao Yamada, 2015, CRC Press) Summary of the invention

[0008] In the case of a gas cluster ion beam, if the average energy of each atom / molecule after collision with the substrate increases, the processing speed of polishing, etching, etc. of the substrate surface tends to increase. In order to increase the processing speed, it is necessary to increase the acceleration voltage (Va) applied to the accelerating electrode set at the exit of the ion generator. When the acceleration voltage is high, the current that can be extracted is generally high. On the other hand, if a gas cluster ion beam extracted at a low acceleration voltage of 10 kV or less is used for irradiation, surface processing (polishing, etching, etc.) can be performed with minimal damage to the substrate. Whether using a beam in a high voltage region or a beam in a low voltage region, it is important to achieve a high irradiation current and arbitrarily control the beam shape to improve processing performance. In a gas cluster ion beam (hereinafter sometimes referred to as GCIB) device, the current and shape of the extractable ion beam depend on the shape and voltage of the extraction electrode. For example, in a system where ion extraction performance is optimized at a certain high acceleration voltage, if the beam energy is increased by simply increasing the acceleration voltage, abnormal discharges frequently occur between the acceleration electrode and the extraction electrode because the distance between the acceleration electrode and the extraction electrode does not change, making it difficult to extract a stable beam. Abnormal discharge can be reduced by increasing the above distance. Generally, when the voltage applied to the accelerating electrode is increased, the distance between the accelerating electrode and the extraction electrode must be increased. On the other hand, when the voltage applied to the accelerating electrode is reduced to a lower voltage while maintaining the system, abnormal discharge does not occur. However, due to insufficient extraction electric field strength, the problem of not being able to obtain sufficient extraction current arises. In order to increase the extraction current, the distance between the accelerating electrode and the extraction electrode must be reduced. In addition, in order to obtain the maximum current and the best beam shape according to the voltage used, in conventional devices, the distance between the accelerating electrode and the extraction electrode and the shape of each electrode must be changed according to each accelerating voltage used. Therefore, in conventional GCIB devices, the distance between the accelerating electrode and the extraction electrode must be adjusted for each voltage when the container is exposed to the atmosphere.

[0009] In addition, conventional GCIB devices are required to be equipped with a permanent magnet type magnet having a magnetic field strength required to remove single-atom / single-molecule single-charged ions (called monomer ions) according to the voltage used. The single-charged ions (monomer ions) of atoms / molecules constituting the cluster beam travel in a straight line without a magnetic field after being deflected in a magnetic field. The orbit radius r increases with the increase of the mass number, and the deflection angle decreases with the increase of the mass number. Therefore, when an appropriate magnetic field strength value is selected according to the distance between the magnet and the irradiated substrate, the single-charged ions can be prevented from hitting the irradiated substrate, and only GCIBs with a high mass number are irradiated. For this reason, the magnetic field strength of the magnet is determined to remove single-charged monomer ions with a specific voltage. However, since a permanent magnet is used, the magnetic field strength cannot be changed. Therefore, when a permanent magnet type magnet is used, if the beam is extracted at an acceleration voltage higher than the design voltage, the orbit radius of the monomer ions becomes larger and the deflection angle becomes smaller, which causes a problem because the beam is irradiated onto the irradiated substrate.

[0010] As described above, in a conventional GCIB apparatus, in order to obtain an optimum beam current and beam shape for each accelerating voltage, the distance between the accelerating electrode and the extracting electrode must be changed, or the existing electrode must be replaced with an electrode having a different shape. The existing permanent magnet type magnet must also be replaced with another permanent magnet type magnet having a magnetic field strength that depends on the voltage. In order to perform such a replacement, the vacuum container must be exposed to the atmosphere at one time. However, such exposure to air causes moisture to be absorbed by the electrode surface, and there is also a problem because a longer time is required to stably apply a high voltage after evacuation. Therefore, there is a need for a GCIB apparatus that can maintain a suitable beam current and beam shape over a wide range of voltages while also being able to remove singly charged monomer ions without changing the permanent magnet type magnet.

[0011] An object of the present invention is to provide a GCIB device that can change the energy of irradiated ions without changing: the electrode arrangement of the GCIB device having an extraction electrode arrangement optimized for a specific voltage, or a permanent magnet type magnet that effectively removes singly charged monomer ions at this voltage, or the magnetic field strength of the permanent magnet type magnet.

[0012] The configuration of the present invention for solving this problem will be described below. For easier understanding, the following description will use the same reference numerals as those used in the description of the embodiment shown in the figures. However, these reference numerals should not be used to interpret the present invention as being limited to only these embodiments.

[0013] The gas cluster ion beam device involved in the present invention comprises a cluster generation chamber 1, a skimmer 4, an ion generator 5, a beam transport system TS and a permanent magnet 21. The cluster generation chamber 1 generates a neutral gas cluster beam of gas atoms or gas molecules by injecting high-pressure gas through a nozzle 3 in a vacuum. The skimmer 4 skims the cluster beam from the central area of ​​the neutral gas cluster beam. The ion generator 5 generates cluster ions by causing the cluster beam introduced through the skimmer 4 to collide with accelerated thermal electrons; the beam transport system TS extracts cluster ions from the ion generator 5 as a gas cluster ion beam 11 through the potential difference between an accelerating electrode 6 arranged at the outlet of the ion generator 5 and applied with a positive high voltage by a high voltage power supply (22a) and an extraction electrode 7 arranged downstream of the accelerating electrode 6; and irradiates the gas cluster ion beam 11 onto an irradiated substrate 15 placed in a vacuum container of an irradiation chamber 12 through one or more electrostatic lenses (9a, 9b) applied with a positive high voltage by a high voltage power supply (22b, 22c). The permanent magnet type magnet 21 included in the beam transport system removes monomer ions. The present invention includes, in addition to the high voltage power supply (22a, 22b, 22c), an independent high voltage power supply 22d for generating a positive high voltage or a negative high voltage, and an independent high voltage applying circuit 27, 27a for applying the positive high voltage or the negative high voltage from the independent high voltage power supply 22d to the ground electrode portion of the extraction electrode 7, the ground electrode portion of the one or more electrostatic lenses (9a, 9b) and the negative terminal portion of the first high voltage power supply, the second high voltage power supply and the third high voltage power supply (22a, 22b, 22c).

[0014] According to the present invention, in the case where the independent high voltage power supply 22d generates a positive high voltage, when the positive high voltage is applied from the independent high voltage power supply 22d to the ground electrode portion of the extraction electrode 7 and the ground electrode portion of the one or more electrostatic lenses (9a, 9b), the ion beam extracted from the ion generator 5 can be irradiated onto the irradiated substrate 15 as a cluster ion beam under the same voltage condition as the following moment: when the positive high voltage or negative high voltage applied from the independent high voltage power supply 22d is added to the positive high voltage applied from the high voltage power supply to the extraction electrode 7 and the one or more electrostatic lenses. On the other hand, in the above-mentioned beam transport system TS, the optimal extraction condition when the original positive voltage is applied is maintained. Therefore, without changing the existing equipment, the energy of the irradiated cluster ion beam can be increased by using the high voltage after adding the positive high voltage applied from the independent high voltage power supply 22d, without changing the electrode arrangement of the GCIB device and the magnetic field strength of the magnet.

[0015] In the case where the independent high-voltage power supply 22d generates a negative high voltage, since the positive high voltage applied to the accelerating electrode 6 provided at the exit of the ion generator 5 reduces the amount of the negative voltage applied by the independent high-voltage power supply 22d, the energy of the cluster ion beam irradiated onto the irradiated substrate 15 is similarly reduced by the amount of the negative voltage. However, even if a negative voltage is applied, the voltage difference at the extraction portion (the portion between the accelerating electrode 6 and the extraction electrode 7) does not change, so the beam can be extracted according to the original voltage difference (electric field strength) and the extraction performance under the optimal extraction conditions can be maintained. Therefore, since the beam transport system TS is at a negative voltage, the beam is decelerated in the space from the beam transport system TS to the irradiated substrate 15 which is at ground potential. As a result, Figure 1 In the conventional device shown, compared with the case where a high voltage with a negative voltage reduction is applied to the accelerating electrode 6 arranged at the exit of the ion generator 5, although the beam is diffused and the irradiated beam current is slightly reduced, there is an advantage that a higher current value can be obtained because the extraction performance is optimized.

[0016] Furthermore, according to another aspect of the present invention, in addition to the high voltage power supply (22a, 22b, 22c), the present invention may also include an independent high voltage power supply 22d that generates a positive high voltage or a negative high voltage, and an independent high voltage applying circuit 27 that applies the positive high voltage or the negative high voltage from the independent high voltage power supply 22d to the ground electrode portion of the extraction electrode 7 and the ground electrode portion of one or more electrostatic lenses (9a, 9b). In addition, each negative terminal portion of the high voltage power supply (22a, 22b, 22c) may be grounded. According to another aspect of the present invention including the above-mentioned elements, the energy of the irradiated cluster ion beam may be increased by adding the high voltage applied from the independent high voltage power supply 22d without changing the electrode arrangement of the GCIB device and the magnetic field strength of the magnet.

[0017] The independent high voltage applying circuit 27 may include a common electrode portion 23 to which the ground electrode portion of the extraction electrode 7 at ground potential, the ground electrode portion of the one or more electrostatic lenses (9a, 9b), and the ground electrode portion directly connected to the permanent magnet type magnet are commonly connected by electrical and mechanical means. In the case where such a common electrode portion 23 is provided, the independent high voltage applying circuit 27 can be configured with a small number of components.

[0018] The common electrode portion 23 is preferably made of a metal integrated electrode plate member (23). The electrode plate member preferably has a structure that mechanically supports the extraction electrode 7, the one or more electrostatic lenses (9a, 9b) and the permanent magnet type magnet 21. If the electrode plate member is attached to the vacuum container 2 in which at least the extraction electrode 7, the one or more electrostatic lenses (9a, 9b) and the permanent magnet type magnet 21 are stored through an insulating glass 24 as an electrical insulator, by using the electrode plate member (23), the extraction electrode, the one or more electrostatic lenses and the permanent magnet type magnet can be supported by a mechanically easy and simple structure.

[0019] As the one or more electrostatic lenses, a structure in which two Einzel lenses are arranged in the direction in which the cluster ion beam passes can be used. In addition, the high voltage power supply may include a first high voltage power supply 22a for applying a high voltage to the acceleration electrode 6, and a second high voltage power supply 22b and a third high voltage power supply 22c for applying a high voltage to the two Einzel lenses 9a, 9b constituting the one or more electrostatic lenses. The permanent magnet type magnet 21 may be arranged between the two Einzel lenses 9a, 9b. Therefore, the two Einzel lenses 9a, 9b have two cylindrical ground electrodes at both ends of the central cylindrical electrode (positive electrode) E3. When the above-mentioned one or more electrostatic lenses are used, the positive high voltage applied from the above-mentioned independent high voltage power supply is applied to the two cylindrical ground electrodes.

[0020] In addition, the accelerating electrode 6 can be electrically coupled to the conductive housing 51 of the ion generator 5, which is fixed on the first electrical connection member La, which is electrically coupled to the first high voltage introduction flange 20a attached to the vacuum container 2. Only the central cylindrical electrode E3 of the two Einsel lenses can be coupled to the second electrical connection member Lb and the third electrical connection member Lc, which are electrically coupled to the second high voltage introduction flange 20b and the third high voltage introduction flange 20c attached to the vacuum container 2. The first electrical connection member La, the second electrical connection member Lb and the third electrical connection member Lc are preferably each made of a metal rod member. In the above case, in addition to the easy arrangement of the permanent magnet type magnet, it also has the following advantages: it is not required to mechanically constitute one or more insulating glasses of one or more Einsel lenses 9a, 9b, and it is easy to supply power to the central cylindrical electrode E3.

[0021] Each of the metal shielding members 26a, 26b and 26c can be fixed to each of the three metal rod members 25 constituting the first electrical connection member La, the second electrical connection member Lb and the third electrical connection member Lc, and the metal shielding member is used to prevent the charged particles generated by the cluster ion beam 11 from reaching the first high voltage introduction flange 20a, the second high voltage introduction flange 20b and the third high voltage introduction flange 20c. By providing the metal shielding members 26a, 26b and 26c, micro discharge can be prevented from occurring between the metal rod member 25 and the inner surface (specifically, the edge portion E) of the vacuum container 2 close to the metal rod member 25. Therefore, the extracted gas cluster ion beam is stable.

[0022] Each of the shielding members 26a, 26b and 26c may have a curved shape, the center of which is fixed to the metal rod member 25, and the curved shape is bent outward from the center to approach the corresponding high voltage introduction flange. The housing having the above shape can effectively prevent charged particles causing micro discharge from penetrating into the shielding members 26a, 26b and 26c.

[0023] The independent high voltage power supply 22d can be a bipolar high voltage power supply that can generate both positive and negative outputs. Therefore, the advantage of the above situation is that high voltage irradiation and low voltage irradiation can be performed on the same irradiated substrate without destroying the vacuum, simplifying the irradiation process.

[0024] In addition, the central magnetic field strength of the permanent magnet type magnet 21 can be a value of 0.1T or greater, which causes deflection so that the SF6 monomer ions in the gas cluster beam containing SF6 extracted from the ion generator at an acceleration voltage of 30 KV do not reach the irradiated substrate. The removal performance of the monomer ions varies with the magnet strength and the straight-line distance from the magnet to the irradiated substrate 15. In an actual device, the straight-line distance from the magnet to the irradiated substrate is about 10 to 60cm. For this straight-line distance, if the magnetic field strength of the magnet is about 0.1 T, since the magnetic field strength increases proportionally with the distance between the magnetic poles as the distance between the magnetic poles decreases, it has the following advantages: regardless of the straight-line distance of 10 to 60 cm, the monomer ions can be easily removed.

[0025] In a specific aspect of the present invention, when the high voltage power supplies 22a, 22b, and 22c output a positive voltage and the independent high voltage power supply 22d applies a positive high voltage, the output voltage of the high voltage power supplies 22a, 22b, and 22c is preferably equal to the output voltage of the independent high voltage power supply 22d. In addition, when the high voltage power supplies 22a, 22b, and 22c output a positive voltage and the independent high voltage power supply 22d applies a positive high voltage, the output voltage of the high voltage power supplies 22a, 22b, and 22c may preferably be higher than the output voltage of the independent high voltage power supply 22d. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a diagram for explaining the structure of a GCIB device previously developed by the inventors, which is an improved object of the present invention.

[0027] Figure 2 It is a diagram for explaining the structure of an example of the first embodiment of the GCIB device of the present invention.

[0028] Figure 3 It is a diagram for explaining the structure of the second embodiment of the GCIB device of the present invention.

[0029] Figure 4 It is a diagram for explaining the structure of the third embodiment of the GCIB device of the present invention.

[0030] Figure 5 It is a diagram for explaining the structure of the fourth embodiment of the GCIB device of the present invention. DETAILED DESCRIPTION

[0031] [Conventional GCIB device]

[0032] Figure 1 1 is a diagram for explaining the configuration of a gas cluster ion beam apparatus (GCIB apparatus) previously developed by the inventors of the present invention, which is an improvement target of the present invention. Figure 1 , the reference numerals are used as follows. 1 represents a cluster generation chamber, 2 represents a vacuum container, 3 represents a nozzle, 4 represents a skimmer, 5 represents an ion generator, 6 represents an accelerating electrode, 7 represents an extraction electrode, 8a, 8b and 8c represent vacuum exhaust pumps, 9a and 9b represent a first Einsel lens and a second Einsel lens constituting an electrostatic lens, and 12 represents a vacuum container for an irradiation chamber. 13 represents a Faraday cup, 14 represents a stage for an irradiated substrate, 15 represents an irradiated substrate, 16 represents a tungsten hot wire, 17 represents an anode rod, 19 represents a high-pressure gas cylinder, 21 represents a permanent magnet type magnet, and 22a, 22b and 22c represent a first high voltage power supply, a second high voltage power supply, and a third high voltage power supply.

[0033] exist Figure 1 In the GCIB device shown as an improvement object, when the SF6 gas introduced into the nozzle 3 from the high-pressure gas cylinder 19 is ejected from the nozzle 3, atoms and molecules condense due to adiabatic expansion, thereby forming a neutral gas cluster beam. Hereinafter, only the neutral gas cluster beam with high density and located in the center is skimmed by the skimmer 4 as a cluster beam, and then the neutral gas cluster beam is introduced into the ionization chamber of the ion generator 5. In the ion generator 5, the thermal electrons generated from the tungsten hot wire 16 are accelerated to several hundred eV (which corresponds to the voltage applied to the anode rod 17), and collide with the neutral cluster beam to cause ionization. Therefore, the neutral gas cluster beam is effectively ionized.

[0034] Note that the first electrical connection member La electrically connected to the first high voltage introduction flange 20a attached to the vacuum container 2 is fixed to the conductive housing 51 of the ion generator 5. Furthermore, the accelerating electrode 6 is fixed to the outlet of the conductive housing 51 and is electrically coupled to the conductive housing 51.

[0035] Next, a voltage of tens of kV (Va in the figure) is applied from the first high voltage power supply 22a to the accelerating electrode 6 through the first high voltage introduction flange 20a, the first electrical connection member La and the conductive shell 51. Due to the voltage difference (= electric field strength) between the accelerating electrode 6 to which a high voltage is applied and the extraction electrode 7 at the ground potential, the cluster ions are extracted from the outlet of the ion generator 5 as an ion beam. Then, the ion beam is transmitted in the first electrostatic lens 9a and the second electrostatic lens 9b composed of the Einsel lens included in the beam transport system TS. The first electrostatic lens 9a and the second electrostatic lens 9b composed of the Einsel lens have cylindrical grounding electrode parts E1 and E2 at both ends of the lens, respectively. Positive high voltages Vb and Vc are applied to the central cylindrical electrode E3 of the first electrostatic lens 9a and the second electrostatic lens 9b from the second high voltage power supply 22b and the third high voltage power supply 22c, respectively. In the first electrostatic lens 9a and the second electrostatic lens 9b, only the cylindrical electrode E3 is coupled to the high voltage introduction flanges 20a and 20b attached to the vacuum container 2. Note that the high voltage introducing flanges 20a, 20b and 20c are fixed to the vacuum container 2 through the insulating glass 10a.

[0036] In the beam transport system TS, a permanent magnet type magnet 21 at ground potential is installed between the first electrostatic lens 9a and the second electrostatic lens 9b. The magnet 21 deflects and removes the monoatomic or monomolecular singly charged ions (hereinafter referred to as monomer ions) contained in the gas cluster ion beam 11, thereby preventing the monomer ions from reaching the irradiated substrate 15. The magnet 21 that removes the monomer ions from the ion generator 5 to the irradiated substrate 15 in the beam transport system TS is a specific configuration for the gas cluster ion beam device.

[0037] The irradiated substrate 15 is positioned in a state where the irradiated substrate 15 is attached to the stage 14 for irradiated substrates in the vacuum container of the irradiation chamber 12. Then, the irradiation of the gas cluster ion beam 11 is performed on the irradiated substrate 15. The Faraday cup 13 measures the current value of the gas cluster ion beam 11. The Faraday cup current measured by the Faraday cup is measured by an ammeter (not shown) placed outside the vacuum container of the irradiation chamber 12 through a cable. When measuring the current value, the stage 14 for irradiated substrates is moved in the direction of the arrow in the figure, and the Faraday cup 13 is moved to a position where the axis of the Faraday cup 13 coincides with the gas cluster ion beam 11, and the current value of the gas cluster ion beam 11 is measured.

[0038] exist Figure 1 In the embodiment, the energy (eV) of the gas cluster ion beam 11 irradiated onto the irradiated substrate 15 at the ground potential is the value obtained by multiplying the voltage (Va, several kV to several tens of kV) applied to the ion generator 5 (accelerating electrode 6) by the ion valence (usually single charge). However, when the gas cluster ion beam 11 is irradiated onto the irradiated substrate 15, the atoms or molecules constituting the gas cluster ion beam 11 will split, diffuse along the surface direction, and etch the irradiated substrate 15, thereby producing the so-called lateral sputtering phenomenon. The average energy of each atom or molecule formed by the dissociation of the gas cluster ion beam 11 is the value of the energy of the above-mentioned gas cluster ion beam divided by the cluster size (number), and is a value in the range of several eV to several tens of eV (several V to several tens of V in voltage conversion). Therefore, compared with a general ion beam processing device that performs surface processing by accelerating single-charged ions to several kV, the device of this embodiment can perform surface processing that causes less damage to the surface structure of the irradiated substrate. In addition, in the case of substrate processing (etching, etc.) using the beam of a typical ion beam processing device, processing is mainly performed in the vertical direction of the substrate surface. Compared with the above-mentioned processing, in the case of processing using a gas cluster ion beam, since the characteristics of the so-called lateral sputtering phenomenon (the above-mentioned atoms or molecules are split, spread in the horizontal surface direction and etched on the irradiated substrate) are utilized, this processing has the advantage of excellent processing performance that achieves surface flattening.

[0039] Note that in order to obtain a beam of several eV to several tens of eV per ion using a general-purpose ion beam processing apparatus using singly charged ions, it is necessary to extract ions directly from an ion source at a voltage of several volts to several tens of volts corresponding to the ion energy. On the other hand, in the case of a general-purpose ion beam processing apparatus, an ion source that extracts ions from a plasma source is generally used. However, since the extraction voltage is insufficient at such a low voltage, the plasma is simply ejected without forming an ion beam, and therefore a large current ion beam cannot be extracted.

[0040] By the way, in the case of a conventional gas cluster ion beam device, an ion beam is extracted by using both an accelerating electrode 6 mounted on an ion generator and an extraction electrode 7 disposed downstream of the accelerating electrode 6. The energy of the extracted ions is several keV to several tens of keV, depending on the voltage of several kV to several tens of kV applied to the accelerating electrode 6. Therefore, the extracted current can also be very high, so that the irradiated ion current irradiated onto the irradiated substrate 15 is at a level of several tens of µA to several hundred µA. Since the cluster size is several hundred particles to several thousand particles on average, the number of particles dissociated after colliding with the surface is several mA to several hundred mA. Therefore, the energy per unit atom is as small as several tens of eV, but a current value equal to or greater than the current value of a general ion beam processing device that extracts singly charged ions at an extraction voltage of several kV can be obtained. Therefore, the surface of the substrate can be etched at high speed.

[0041] However, in order to obtain the maximum current and the best beam shape corresponding to the voltage to be used, it is required to Figure 1 In the GCIB apparatus shown, the distance between the accelerating electrode 6 and the extracting electrode 7 or the shapes of the accelerating electrode 6 and the extracting electrode 7 are changed for each accelerating voltage to be used. Therefore, the distance between the accelerating electrode 6 and the extracting electrode 7 must be adjusted for each voltage to be used while the container is exposed to the atmosphere.

[0042] In addition, in order to Figure 1 In the GCIB apparatus shown, in order to extract beams at different acceleration voltages, a permanent magnet type magnet 21 with sufficient magnetic field strength must be equipped to remove single atomic / monomolecular single-charged ions (called monomer ions) according to the voltage to be used. The single-charged ions (monomer ions) of atoms / molecules constituting the cluster ion beam travel in a straight line in the absence of a magnetic field after being deflected in the magnetic field space. The orbital radius r of the ion beam in the permanent magnet type magnet 21 increases with the increase of the mass number, and the deflection angle decreases with the increase of the mass number. Therefore, when an appropriate magnetic field strength value is selected according to the distance between the magnet 21 and the irradiated substrate 15, the single-charged ions can be prevented from hitting the substrate, and only GCIB with a high mass number is irradiated. The magnetic field strength of the magnet 21 is determined to remove single-charged monomer ions with a specific voltage. However, since a permanent magnet is used as the magnet 21, the magnetic field strength cannot be changed. Therefore, when the magnet 21 is used, if the beam is extracted at an acceleration voltage higher than the designed voltage, the orbit radius of the monomer ions becomes larger and the deflection angle becomes smaller, which causes a problem because the beam is irradiated onto the irradiated substrate 15 .

[0043] Therefore, in Figure 1In the GCIB apparatus shown, in order to obtain the optimum beam current and beam shape for each accelerating voltage, it is necessary to change the distance between the accelerating electrode 6 and the extracting electrode 7, or replace the electrode having the existing shape with an electrode having a different shape. It is also necessary to replace the existing magnet with a permanent magnet type magnet 21 whose magnetic field strength varies with voltage. Although the vacuum container 2 must be exposed to the atmosphere once in order to perform such a replacement, this exposure to the air may cause moisture absorption on the electrode surface, which may also cause problems because it takes a longer time to stably apply a high voltage after evacuation. Therefore, there is a need for a GCIB apparatus that can maintain a suitable beam current and beam shape over a wide range of voltages while also being able to remove singly charged monomer ions without changing the permanent magnet type magnet 21.

[0044] [First embodiment]

[0045] Figure 2 is a diagram showing the configuration of an embodiment of a GCIB device according to the present invention, for solving Figure 1 In this embodiment, the conventional GCIB device is used to solve the above problems. Figure 1 The same reference numerals in the figure denote Figure 1The GCIB device of this embodiment also generates a cluster beam of gas atoms or gas molecules by injecting high-pressure gas through a nozzle 3 in a vacuum, and also introduces a beam of the cluster beam located in the central area into an ion generator 5 through a skimmer 4. The ion generator 5 generates cluster ions by colliding accelerated thermal electrons with a cluster beam. Then, ions are extracted from the ion generator 5 as a cluster ion beam by an accelerating electrode 6 disposed at the outlet of the ion generator 5 and applying a positive high voltage thereto, and an extraction electrode 7 disposed downstream of the accelerating electrode 6. In a state where a positive high voltage is applied from a first high voltage power supply 22a, a second high voltage power supply 22b, and a third high voltage power supply 22c to the extraction electrode 7 and the one or more electrostatic lenses 9a, 9b, the gas cluster ion beam 11 is irradiated onto an irradiated substrate 15 placed in a vacuum container 12 for an irradiation chamber through a beam transport system TS including electrostatic lenses 9a, 9b and a permanent magnet type magnet 21. In addition to the first high voltage power supply 22a, the second high voltage power supply 22b and the third high voltage power supply 22c, the present embodiment also includes an independent high voltage power supply 22d that generates a positive high voltage, and an independent high voltage applying circuit 27 that applies the independent high voltage provided by the independent high voltage power supply 22d to the common electrode portion 23 and the ground electrode portion of the one or more electrostatic lenses 9a, 9b. The common electrode portion 23 includes an electrode plate member made of a metal plate and provides a ground electrode portion of the extraction electrode 7. In the present embodiment, the independent high voltage applying circuit 27 includes a circuit portion 27a that couples the negative terminal portions of the first high voltage power supply 22a, the second high voltage power supply 22b and the third high voltage power supply 22c to the positive electrode portion of the independent high voltage power supply 22d, respectively. In the present embodiment, the independent high voltage applying circuit 27 is connected to the common electrode portion 23, which is electrically or mechanically connected to the ground electrode portion of the extraction electrode 7, the cylindrical ground electrode portions E1 and E2 other than the central positive electrode constituting the electrostatic lens, and the ground electrode portion of the magnet 21. The common electrode portion 23 is made of a metal integrated electrode plate member. The common electrode portion 23 made of the electrode plate member has a structure that mechanically supports the extraction electrode 7, the electrostatic lenses 9a, 9b, and the permanent magnet type magnet 21. Since the common electrode portion 23 made of the electrode plate member is attached to the vacuum container 2 in which the extraction electrode 7, the electrostatic lenses 9a, 9b, and the permanent magnet type magnet 21 are stored through the insulating glass 24 as an electrical insulator, by using the common electrode portion 23, the extraction electrode 7, the electrostatic lenses 9a, 9b, and the permanent magnet type magnet 21 can be supported by a mechanically easy and simple structure. Such a common electrode portion 23 simplifies the construction of the independent high voltage application circuit 27 with a small number of components.

[0046] In the present embodiment, the positive high voltage generated from the independent high voltage power supply 22d is applied to the ground electrode portion of the extraction electrode 7 and the two ground electrodes E1 and E2 located at both ends of the central cylindrical electrode E3 (positive electrode) of the electrostatic lenses 9a and 9b. In the above structure, the ion beam extracted from the ion generator 5 is irradiated onto the irradiated substrate 15 as a beam generated under the same voltage condition as at the time when the positive high voltage applied from the independent high voltage power supply 22d is added to the positive high voltage applied from the first high voltage power supply 22a, the second high voltage power supply 22b, and the third high voltage power supply 22c to the extraction electrode 7 and the electrostatic lenses 9a and 9b. Therefore, without changing the existing equipment, the energy of the irradiated ions can be increased by using the high voltage after adding the positive high voltage applied from the independent high voltage power supply 22d, without changing the electrode arrangement of the GCIB device and the magnetic field strength of the magnet 21.

[0047] In this embodiment, when the output generated by the independent high voltage power supply 22d is applied to the electrode plate member constituting the common electrode portion 23, if the voltage value of the independent high voltage power supply 22d is +Vd, the voltage value of the ion generator 5 is Vd+Va with respect to the ground potential. On the other hand, since the extraction electrode 7 is biased by Vd in the extraction region, the potential difference between the acceleration electrode 6 and the extraction electrode 7 is maintained at Va. In addition, since the potential of the irradiated substrate 15 is the ground potential, Figure 2 The gas cluster ion beam 11 in the irradiation device is irradiated onto the irradiated substrate 15 with energy corresponding to the voltage of Vd+Va. On the other hand, since the beam transport system TS composed of the electrostatic lenses 9a, 9b and the permanent magnet type magnet 21 is also biased by Vd, the singly charged ions are deflected by the magnetic field corresponding to the energy depending on the voltage Va. Therefore, the orbit radius r does not change, and the characteristics of removing singly charged monoatomic / monomolecular ions (monomer ions) are the same as those in the conventional case. Therefore, according to the present embodiment, while maintaining the performance of the optimized beam line under the acceleration voltage Va, the ion energy flowing into the irradiated substrate 15 can be increased.

[0048] In the present embodiment, the voltage Vd applied from the independent high voltage power supply 22d is a positive high voltage as described above, but the voltage Vd may also be a negative high voltage (-Vd). In this way, the irradiation energy can be reduced to Va-Vd without changing the beam extraction performance under the positive high voltage Vd. In the case where the independent high voltage power supply 22d outputs a negative high voltage, since the positive high voltage applied to the conductive housing 51 of the ion generator 5 is reduced by only the amount of the negative voltage applied from the independent high voltage power supply 22d, the energy of the ion beam irradiated onto the irradiated substrate 15 is also reduced by only the amount of the negative voltage. However, since the voltage difference of the extraction part (the part between the acceleration electrode 6 and the extraction electrode 7) does not change even if a negative voltage is applied, the beam can be extracted with the original voltage difference (electric field strength) and the extraction performance under the optimized extraction condition can be maintained. In the above case, since the beam delivery system is at a negative voltage, the speed of the beam is reduced in the space from the beam delivery system to the irradiated substrate 15 at the ground potential. As a result, the beam spreads and the irradiated beam current tends to decrease slightly. However, since the extraction performance is optimized, there is an advantage that a higher current can be obtained compared to applying a high voltage with a reduced negative voltage to the conductive shell 51 of the ion generator 5. The above configuration can be achieved because the permanent magnet type magnet 21 is provided at the center between the first electrostatic lens 9a and the second electrostatic lens 9b, and the permanent magnet type magnet 21 can be provided on the insulating common electrode portion 23 together with the first electrostatic lens 9a and the second electrostatic lens 9b.

[0049] Next, we will explain the actual implementation Figure 2 The first example of the embodiment shown in . The first example is an ion beam generated using argon gas or argon gas containing sulfur hexafluoride (SF6) gas as a gas cluster ion beam. A DC voltage of a high voltage power supply 22a with a maximum output voltage of 30 kV is applied to the conductive shell 51 of the ion generator 5. A 30 kV voltage applied from an independent high voltage power supply 22d is applied to the first high voltage power supply 22a. As a result, the energy of the gas cluster ions irradiated onto the irradiated substrate 15 is at a level of 60 keV, corresponding to a voltage of 60 kV. The tungsten hot wire 16 provided in the ion generator 5 is heated by energizing to a temperature sufficient to emit thermal electrons. A DC voltage of several hundred V is applied to the space between the tungsten hot wire 16 and the anode rod 17, and the cluster beam is ionized by accelerating the thermal electrons. In order to efficiently extract the gas cluster ion beam, an extraction electrode 7 having a mountain-shaped vertical cross-sectional shape as shown in the figure is used. In addition, the extraction electrode 7 is directly fixed to the metal plate constituting the common electrode 23. The distance between the acceleration electrode 6 and the extraction electrode 7 is about 10 mm. At this distance, operation at 30 kV provides maximum current and minimum inter-electrode discharge.

[0050] The first electrostatic lens 9a and the second electrostatic lens 9B are respectively composed of cylindrical Einsel lens configurations. The Einsel lens includes a cylindrical electrode made of stainless steel. The permanent magnet type magnet 21 to be used is a two-pole (dipolar) magnet, in which the N pole and the S pole of the permanent magnet are arranged facing each other. Specifically, a dipolar magnet with a central magnetic field of 0.1T (Tesla) or more is used. The magnetic field strength is a value of the magnetic field strength that will obtain the following deflection angle: at this deflection angle, a single-charged SF6 single-molecule monomer ion (SF6 + ) will not be irradiated onto the irradiated substrate 15. If the argon cluster beam passes through the above magnet, due to the argon monomer ions (Ar + ) is less than the mass number of SF6 monomer ions, the deflection radius in the magnetic field becomes smaller, thereby the deflection angle becomes larger, and the argon cluster beam does not collide with the substrate. The removal of monomer ions is confirmed by the so-called time-of-flight mass spectrometry. Next, a voltage of +30 kV is applied to the metal plate used for the common electrode 23 from an independent high-voltage power supply 22d. Therefore, the optimal extraction condition of 30 kV is maintained between the acceleration electrode 6 and the extraction electrode 7. Next, the voltages Vb and Vc applied to the central cylindrical electrode E3 of the electrostatic lenses 9a and 9b are applied as the optimal voltages when extraction is performed at 30 kV from the high-voltage power supplies 22b and 22c. In addition, the negative electrode terminals of the high-voltage power supplies 22b and 22c are coupled to the +30 kV output terminals of the independent high-voltage power supply 22d. Note that if the value of the voltage Vd of the independent high-voltage power supply 22d is set to 0 V in the above state, it will obviously be achieved with Figure 1 The examples shown in FIG. 1 have the same extraction conditions and the same delivery conditions.

[0051] First, the voltage Vd applied from the independent high voltage power supply 22d is set to 0V to emit the beam, and the Faraday cup 13 having an opening diameter of 35mm and disposed in the irradiation chamber vacuum container 12 is moved to a position facing the beam. The wire coupled to the Faraday cup 13 is connected to the outside of the vacuum space, and the current is measured with an ammeter ( Figure 2ion current is measured by adjusting the voltage Vb, Vc of the central cylindrical electrode E3 of the one or more electrostatic lenses 9a, 9b. When the voltage Vb, Vc applied to the one or more electrostatic lenses 9a, 9b is adjusted, a current of 100μA or more is obtained as the Faraday cup current in the Ar-GCIB. In the above state, when the voltage Vd of the independent high voltage power supply 22d is set to 30kV, when no discharge is generated between the accelerating electrode 6 and the extraction electrode 7, a current of the same level or more of 100μA is measured as the value of the Faraday cup current. In the above case, the energy of the cluster ion beam is 60keV. In addition, when the beam is statically irradiated onto a Si substrate with a SiO2 film and the irradiation mark is observed, the shape of the irradiation mark is about 3 mm to 5 mm in diameter. Since the irradiation mark at 30kV (Vd=0kV) alone is in the shape of 5 mm to 10 mm in diameter, it is confirmed that the beam convergence is also effective. This is probably because by increasing the energy from 30 keV to 60 keV, the beam divergence from the second-stage electrostatic lens 9b to the irradiated substrate 15 was suppressed. Similarly, in the experiment using the gas containing SF6, the Faraday cup current value at 30 kV alone (Vd = 0 kV) and the Faraday cup current value when Vd = 30 kV was added to 30 kV (Vd = 0 kV) were compared, and it was confirmed that almost the same current value of 200 μA or more was obtained in both results.

[0052] Note that although Ar gas or SF6 gas is used as the gas of GCIB in the example, it has been confirmed according to the experiments conducted by the inventors that even when a gas species that forms clusters [e.g., NF3, CF4, O2, CO2 gas and a gas obtained by mixing the above gases with a rare gas (Ar, He, etc.)] is used, a gas cluster ion beam that does not contain monomer ions and has a high current value can be obtained. In the above case, since the magnetic field strength of the permanent magnet type magnet 21 is set to a value (>0.1T) that can deflect and remove the monomer ions of SF6, a gas cluster ion beam that does not contain monomer ions can be obtained even when the above gas species with a molecular weight lower than that of SF6 is used. This is because the magnet is designed to have a magnetic field strength value that can remove SF6 monomer ions, so that the orbital radius of ions of gas species with a mass number lower than the mass number of SF6 becomes smaller than the orbital radius of SF6 monomer ions, and the deflection angle of ions at the magnet outlet becomes larger. Therefore, the orbit after leaving the magnet significantly deviates from the straight beam path, and the monomer ions of the above gas species cannot reach the irradiated substrate. Note that the Faraday cup current value of gas species other than Ar gas and SF6 gas varies depending on the aggregation sensitivity and ionization efficiency of each gas.

[0053] In the second example, Figure 2The independent high voltage power supply 22d shown uses a high voltage power supply that generates a negative voltage. The operating conditions other than the above conditions are the same as those in the first example. That is, the value of the voltage Va is set to 30 kV, and the value of the voltage Vd in the independent high voltage power supply 22d is set to -10 kV as operating conditions. In this case, the potential of the conductive housing 51 of the ion generator 5 is set to 20 kV relative to the potential of the irradiated substrate 15 (i.e., the ground potential). In the same state of measuring the current of the Ar-GCIB applied to the Faraday cup 13, a current value of about 100 μA was obtained. As can be understood from the above, in terms of beam extraction and delivery efficiency, it is clearly seen that the performance at only 30 kV is maintained. When observing the irradiation mark using Ar-GCIB, in the case of Vd=-10 kV, the irradiation mark is about 10–15 mm, because the diameter of the beam irradiation mark is slightly enlarged compared to the case of Vd=0 kV. This is because the beam divergence effect is enhanced due to the lower energy. It is considered that the beam divergence effect mainly works in the space from the second electrostatic lens 9b to the irradiated substrate 15. In fact, when the state (Vd = -10 kV) is maintained and the voltages Vb and Vc of the first electrostatic lens 9a and the second electrostatic lens 9b are adjusted, the diameter of the beam irradiation mark is reduced to about 8 mm. Note that even if a bipolar high voltage power supply that can switch positive and negative voltages and generate both positive and negative voltages is used as the independent high voltage power supply 22d, it is easy to switch between the above-mentioned positive high voltage power supply only and the negative high voltage power supply only.

[0054] [Second embodiment]

[0055] Figure 3 1 is a diagram showing the configuration of a second embodiment of the present invention. Figure 1 Components identical or similar to those used in the conventional GCIB device shown, and Figure 2 The present embodiment uses the same or similar components as those used in the first embodiment shown in FIG. Figure 1 and Figure 2 The present embodiment is also configured such that the ground electrode portions E1 provided at both ends of the electrostatic lens 9a and the electrostatic lens 9b are directly fixed to the common electrode portion 23, and the electrode portion E2 at the opposite side of the ground electrode portion E1 is fixed to the magnet 21, and the magnet 21 is connected to the common electrode portion 23. Figure 2The same as the first embodiment shown in FIG. However, the second electrical connection member Lb and the third electrical connection member Lc that electrically couple the central cylindrical electrode E3 constituting the first electrostatic lens 9a and the second electrostatic lens 9b to the high voltage introduction flanges 20b and 20c are formed by the metal rod portion 25 in this embodiment. That is, the first electrostatic lens 9a and the second electrostatic lens 9b can be fixed to the high voltage introduction flanges 20b and 20c by the second electrical connection member Lb and the third electrical connection member Lc made of the metal rod member 25. In this case, Figure 2 Compared with the embodiment shown in FIG. 1 , the insulating glass 10b is not required at all in this embodiment. Therefore, since the inter-electrode discharge (creeping discharge) through the insulating glass 10b does not occur, the operation of the electrostatic lens is stable, so that the lens action is maintained stably and the beam current is stable.

[0056] Note that Figure 3 In the configuration shown, an example of a beam with Va=30kV and Vd=30kV is generated. When extracting from a GCIB containing Ar-CIB and SF6 gas, because the surface discharge generated by the insulating glass installed inside the electrostatic lens does not occur, a stable beam is extracted without generating discharge, etc. for hundreds of hours. When a lens system including insulating glass is used, dirt will adhere to the surface of the insulating glass due to the sputtering of the beam to the metal part. As a result, after 100 hours, discharge will occur several times per hour. In this case, due to the induction of discharge, the unstable state of the high voltage power supply, etc. increases, resulting in occasional current extraction failure. In the present embodiment, not only is no discharge generated, but the current performance or beam shape does not change, and stable operation can be achieved for a long time, and in actual use, the effect of stable operation is also very large.

[0057] Figure 4 1 is a diagram showing the configuration of a third embodiment of the present invention. Figure 1 Components identical and similar to those used in the conventional GCIB apparatus shown, and Figure 2 The present embodiment also uses the same and similar components as those used in the first embodiment shown. Figure 1 and Figure 2 Although Figure 2The first embodiment shown includes a circuit portion 27a of the independent high voltage applying circuit 27 that couples the negative terminal portions of the first high voltage power supply 22a, the second high voltage power supply 22b, and the third high voltage power supply 22c to the positive terminal portion of the independent high voltage power supply 22d, respectively, but in the present embodiment, all the negative terminal portions of the first high voltage power supply 22a, the second high voltage power supply 22b, and the third high voltage power supply 22c are grounded. In the present embodiment, the independent high voltage power supply 22d is coupled only to the common electrode portion 23 of the beam transport system TS. In addition, the output voltage Vb of the independent second high voltage power supply 22b and the output voltage Vc of the independent third high voltage power supply 22c are respectively supplied to the cylindrical electrode E3. The independent high voltage power supply 22d in the present system is coupled only to the common electrode portion 23. In the above case, when the voltage Vd of the independent high voltage power supply 22d is set to 30 kV, if a power supply in which the maximum output voltages Va, Vb and Vc of the first high voltage power supply 22a, the second high voltage power supply 22b and the third high voltage power supply 22c are set to 60 kV is used, the respective voltage values ​​are the same as those of the first embodiment and the second embodiment.

[0058] exist Figure 4 In the third embodiment shown, the configuration in which the voltage Vb and the voltage Vc relative to the ground potential are directly applied to the cylindrical electrode E3 (anode) is similar to Figure 1 The same conventional configuration as shown. Figure 4 In the third embodiment shown, Figure 2 and Figure 3 The configuration of the first embodiment and the second embodiment shown in FIG. 1 is the same, except that the configuration of applying the positive voltage Vd generated by the independent high voltage power supply 22d to the extraction electrode 7 is the same as that of the first embodiment and the second embodiment shown in FIG. Figure 1 In addition, the configuration in which the positive voltage Vd generated by the independent high voltage power supply 22d is applied to the ground electrode portion E1 of the electrostatic lens 9a and the ground electrode portion E2 of the electrostatic lens 9b is different from that in Figure 1 The configuration shown is different.

[0059] exist Figure 1 In the conventional example shown, the energy of the cluster beam extracted using the extraction electrode 7 at ground potential is energy corresponding to the voltage Va applied by the first high voltage power supply 22a. For example, when the voltage of the first high voltage power supply 22a is set to 60 kV, the energy of the cluster beam is 60keV. In addition, the extracted cluster beam passes through an environment that is generally maintained at ground potential except for the cylindrical electrode E3 located in the center and serving as an anode within the electrostatic lenses 9a and 9b. As a result, the cluster beam is subjected to the action of the electrostatic lenses 9a, 9b as a 60keV beam. Therefore, in Figure 1In the conventional example shown, the voltage Vb and the voltage Vc required to effectively transmit the beam applied to the cylindrical electrode E3 are 50 kV to 60 kV. Figure 4 In the embodiment, when the voltage Vd applied by the independent high voltage power supply 22d is set to 30 kV, since the beam passes through the 30 kV electrical environment in the electrostatic lenses 9a, 9b, the beam subtracted to a 30 keV beam is effectively affected by the electrostatic lenses 9a, 9b. Figure 4 In the third embodiment shown, the voltage applied to the cylindrical electrode E3 (anode) is sufficient to achieve the voltage required to transmit a beam of 30keV, and therefore, the above required voltage plus the voltage applied to the common electrode portion 23 is sufficient. In fact, in the example of the third embodiment where a voltage of 30kV is applied to the common electrode portion, a voltage of less than 50kV applied to the cylindrical electrode E3 is sufficient. Therefore, according to the present embodiment, it can be confirmed that no abnormal discharge occurs in the electrostatic lenses 9a, 9b and the extraction electrode 7, and the performance of the obtained current and the shape of the beam are also the same as the results of the examples of the first and second embodiments.

[0060] [Fourth embodiment]

[0061] In the present invention Figure 2 The first embodiment shown, Figure 3 The second embodiment shown and Figure 4 In the third embodiment shown, it has been confirmed that micro discharges are easily generated in the tiny space between each of the first electrical connection member La, the second electrical connection member Lb and the third electrical connection member Lc (wiring or metal rod member 25) and the peripheral portion (specifically, between the wiring or metal rod member 25 and the inner edge E of the vacuum container 2), wherein the first electrical connection member La, the second electrical connection member Lb and the third electrical connection member Lc couple each of the first high voltage introduction flange 20a, the second high voltage introduction flange 20b and the third high voltage introduction flange 20c with each of the ion generator 5 and the cylindrical electrode E3. This is because, in the first to third embodiments, as described above, the beam in the first electrostatic lens 9a and the second electrostatic lens 9b is transmitted as a beam that effectively corresponds to the low voltage energy, and therefore the beam tends to diffuse. When the current value applied by the power supply is the same, the greater the energy, the smaller the degree of diffusion. Figure 1In the conventional example shown, when the voltage is set to, for example, 60 kV and applied to the ion generator 5, the ions are transmitted through the electrostatic lenses 9a, 9b while maintaining a high energy of 60 keV, and are irradiated as a 60 keV beam onto the irradiated substrate 15. On the other hand, in the examples of the first to third embodiments, a high voltage Vd (for example, 30 kV) generated by an independent high voltage power supply 22d is applied to the common electrode portion 23, and when the applied voltage Va applied to the ion generator 5 is set to 30 kV, a 60 keV beam is irradiated onto the irradiated substrate (ground potential), which is the same as the ground potential. Figure 1 As a result, the beam is more likely to collide with electrodes (E1 to E3) and the like, and secondary charged particles are more likely to be emitted from the electrode surface by collision. In addition, even in the peripheral space of the diffuse beam, a large number of collisions between the beam and the residual gas (neutral particles) tend to occur. Some of these charged particles also tend to scatter into the surrounding space. Experiments have confirmed that these charged particles trigger micro-discharges between the inner surface of the vacuum container 2 (particularly the edge portion E) and the first electrical connection member La, the second electrical connection member Lb and the third electrical connection member Lc (wiring or metal rod member 25) and the anode rod 17 that applies voltage to the ion generator 5. In addition, in the first to third embodiments, it is also confirmed from the beam trajectory calculation simulation that the beam tends to diffuse in the electrostatic lenses 9a, 9b.

[0062] In order to solve the above problems, a Figure 5 The fourth embodiment shown. Figure 1 Components identical or similar to those used in the conventional GCIB device shown, and Figure 2 The fourth embodiment also uses the same or similar components as those used in the first embodiment shown. Figure 1 and Figure 2The same figure marks are used in the figure. In the fourth embodiment, the first electrical connection member La, the second electrical connection member Lb and the third electrical connection member Lc that electrically connect the first high voltage introduction flange 20a, the second high voltage introduction flange 20b and the third high voltage introduction flange 20c to the ion generator 5 and the cylindrical electrode E3 (anode) are each made of a metal rod member 25. In addition, each of the metal shielding members 26a, 26b and 26c is respectively fixed to each of the three metal rod members 25. The metal shielding members 26a, 26b and 26c prevent secondary charged particles (mainly electrons) from reaching the first high voltage introduction flange 20a, the second high voltage introduction flange 20b and the third high voltage introduction flange 20c. The secondary charged particles (mainly electrons) are generated from the electrodes by the above-mentioned beam divergence collision, or by the collision between the gas cluster ion beam 11 and the gas molecules around the divergence. Each of the shielding members 26a, 26b and 26c of the present embodiment has a curved shape, the center of the curved shape is fixed on the metal rod member 25, and the curved shape is bent outward from the center to approach the corresponding high voltage introduction flange. It has been experimentally confirmed that the above-mentioned shielding members 26a, 26b and 26c can prevent micro-discharges between the three metal rod members 25 constituting the first electrical connection member La, the second electrical connection member Lb and the third electrical connection member Lc and the inner surface of the vacuum container 2 located near the three metal rod members 25. Thus, it is also confirmed that the extracted gas cluster ion beam 11 can be stably obtained. Note that if the shielding members 26a, 26b and 26c each adopt a curved shape, it is also confirmed that charged particles causing micro-discharges are effectively prevented from penetrating into the shielding members 26a, 26b and 26c. Note that it has been confirmed that even in the configurations in the first and second embodiments, it is effective to reduce micro-discharges by installing metal shielding members 26a, 26b and 26c.

[0063] In the above-described embodiment, the first to third high voltage power supplies are described as being each an independent high voltage power supply, but of course, a common high voltage power supply may also be used.

[0064] [Effects of Embodiment]

[0065] According to the first to fourth embodiments described above, ionization achieved by electron beam impact can generate gas cluster ions, wherein a gas is sprayed into a vacuum at a pressure of several atmospheres to several tens of atmospheres through a fine nozzle, and a cluster beam (neutral) is generated as a group of hundreds to thousands or more gas molecules and gas atoms gathered. Then, the gas cluster ions are extracted from the ion generator 5 by the extraction electrode 7 at a high voltage and turned into an ion beam. Thereafter, a gas cluster ion beam device can be provided, which can irradiate the beam onto the irradiated substrate 15 through a beam transport system TS composed of an electrostatic lens 9a, 9b and a permanent magnet type magnet 21 as a magnetic field generating device. According to the use of the device of this embodiment, the entire surface layer of μm to mm level formed on the surface of the irradiated substrate 15 can be etched or flattened with almost no damage to the surface roughness.

[0066] In addition, according to the present embodiment, a GCIB device can be realized, which can easily obtain beams with different energies of GCIB optimized for a specific acceleration voltage without changing the distance between the acceleration electrode 6 and the extraction electrode 7 or the shape of the acceleration electrode 6 and the extraction electrode 7, and without changing the magnetic field strength of the magnet introduced into the beam transport system TS. Thus, a stable and efficient gas cluster ion beam can be irradiated within a wide energy range (acceleration voltage range). In addition, cluster ion beams with different energies can be continuously irradiated to the same irradiated substrate. For example, the sample is etched in a high voltage area, and then low-energy irradiation is added, so that high-speed and flat gas cluster ion beam processing can be performed. Surface treatment processing of piezoelectric element materials is regarded as a field that requires the above-mentioned processing. The device of the present invention can provide a GCIB irradiation device that can be processed at a higher speed and has fewer surface defects.

[0067] Industrial Applicability

[0068] According to the present invention, in the case where the independent high voltage power supply generates a positive high voltage or a negative high voltage, when the positive high voltage or the negative high voltage is applied from the independent high voltage power supply to the ground electrode portion of the extraction electrode and the ground electrode portion of the one or more electrostatic lenses, the ion beam extracted from the ion generator can be irradiated on the irradiated substrate as the generated beam under the same voltage condition as the following moment: when the positive high voltage or the negative high voltage applied from the independent high voltage power supply is added to the positive high voltage applied from the high voltage power supply to the extraction electrode and the one or more electrostatic lenses. Therefore, without changing the existing equipment, the energy of the irradiated ion beam can be increased by using the high voltage after adding the positive high voltage applied from the independent high voltage power supply, without changing the electrode arrangement of the GCIB device and the magnetic field strength of the magnet.

[0069] Explanation of symbols

[0070] 1 Cluster Generation Chamber

[0071] 2 Vacuum container

[0072] 3 Nozzles

[0073] 4 Skimmer

[0074] 5. Ion Generator

[0075] 6 Accelerating electrode

[0076] 7 Extraction Electrode

[0077] 8a-8b vacuum exhaust pump

[0078] 9a, 9b first electrostatic lens and second electrostatic lens

[0079] 10a, 10b insulating glass

[0080] 11 Gas Cluster Ion Beam (GCIB)

[0081] 12 Irradiation chamber vacuum container

[0082] 13 Faraday Cup

[0083] 14 Stage for irradiated substrate

[0084] 15 Irradiated substrate

[0085] 16 Tungsten hot wire

[0086] 17 Anode rod

[0087] 18 Pressure reducing cock

[0088] 19 cylinders

[0089] 20a, 20b, 20c first to high voltage introduction flange

[0090] 21Permanent magnet

[0091] 22a, 22b, 22c first to third high voltage power supplies

[0092] 22d Independent high voltage power supply

[0093] 23 Common electrode part (metal plate)

[0094] 24 Insulation glass

[0095] 25 Metal rod components

[0096] 26a, 26b, 26c shielding components.

Claims

1. A gas cluster ion beam device, comprising: Cluster generation chamber, which generates neutral gas cluster beams of gas atoms or gas molecules by injecting high-pressure gas through a nozzle in a vacuum. a skimmer, skimming the cluster beam from a central region of the neutral gas cluster beam, an ion generator for generating cluster ions by causing the cluster beam introduced through the skimmer to collide with accelerated thermal electrons, A beam delivery system extracts the cluster ions from the ion generator as a cluster ion beam by a potential difference between an accelerating electrode disposed at the outlet of the ion generator and to which a positive high voltage is applied by a high voltage power supply and an extracting electrode disposed downstream of the accelerating electrode; and irradiates the cluster ion beam onto an irradiated substrate placed in a vacuum container of an irradiation chamber through one or more electrostatic lenses to which a positive high voltage is applied by the high voltage power supply, a permanent magnet type magnet, contained in the beam transport system and removing monomer ions, an independent high voltage power supply that generates a positive high voltage or a negative high voltage independently of the high voltage power supply, and An independent high voltage applying circuit applies a positive high voltage or a negative high voltage from the independent high voltage power supply to the ground electrode portion of the extraction electrode, the ground electrode portion of the one or more electrostatic lenses, and the negative terminal portion of the high voltage power supply.

2. A gas cluster ion beam device, comprising: a cluster generation chamber into which high-pressure gas is injected through a nozzle in a vacuum to generate a neutral gas cluster beam consisting of gas atoms or molecules, a skimmer, selecting a cluster beam in a central region of the neutral gas cluster beam, an ion generator for generating cluster ions by subjecting the cluster beam introduced through the skimmer to collision ionization with accelerated thermal electrons, A beam transport system TS extracts the cluster ions from the ion generator as a cluster ion beam by a potential difference between an accelerating electrode to which a positive high voltage is applied by a high voltage power supply disposed at the outlet of the ion generator and which is grounded by a negative terminal portion and an extracting electrode disposed downstream of the accelerating electrode; and irradiates the cluster ion beam onto an irradiated substrate placed in a vacuum container of an irradiation chamber by one or more electrostatic lenses to which a positive high voltage is applied by the high voltage power supply which is grounded by a negative terminal portion, a permanent magnet type magnet, contained in the beam transport system and removing monomer ions, an independent high voltage power supply that generates a positive high voltage or a negative high voltage independently of the high voltage power supply, and An independent high voltage applying circuit applies a positive high voltage or a negative high voltage from the independent high voltage power source to the extraction electrode and the ground electrode portion of the one or more electrostatic lenses.

3. The gas cluster ion beam device according to claim 1 or 2, wherein: The independent high voltage applying circuit includes a common electrode portion to which the ground electrode portion of the extraction electrode, the ground electrode portions of the one or more electrostatic lenses, and the ground electrode portion directly connected to the permanent magnet type magnet are electrically and mechanically commonly connected.

4. The gas cluster ion beam device according to claim 1 or 2, wherein: The independent high voltage applying circuit is electrically coupled to a common electrode portion, to which the ground electrode portion of the extraction electrode, the ground electrode portion of the one or more electrostatic lenses, and the ground electrode portion directly connected to the permanent magnet type magnet are commonly connected by electrical or mechanical means, The common electrode portion is made of a metal integrated electrode plate component. The electrode plate member has a structure that mechanically supports the extraction electrode, the one or more electrostatic lenses, and the permanent magnet type magnet, and The electrode plate member is attached to a vacuum container through an electrical insulator, in which at least the extraction electrode, the electrostatic lens, and the permanent magnet type magnet are stored.

5. The gas cluster ion beam device according to claim 1 or 2, wherein: The one or more electrostatic lenses include two Einsel lenses arranged along the passing direction of the cluster ion beam, The high voltage power supply includes a first high voltage power supply for applying a high voltage to the accelerating electrode, and a second high voltage power supply and a third high voltage power supply for applying a high voltage to the two Einsel lenses constituting the one or more electrostatic lenses, The permanent magnet is arranged between the two Einsel lenses. The two Einsel lenses have two cylindrical ground electrodes at both ends of the central cylindrical electrode. A positive high voltage applied from the independent high voltage power supply is applied to the two cylindrical ground electrodes, The accelerating electrode is electrically coupled to the ion generator fixed to a first electrical connection member, the first electrical connection member is electrically coupled to a first high voltage introduction flange attached to the vacuum container, and Only the central cylindrical electrodes of the two Einsel lenses are coupled to second and third electrical connection members, which are electrically coupled to second and third high voltage introduction flanges attached to the vacuum container.

6. The gas cluster ion beam device according to claim 5, wherein: The first electrical connection member, the second electrical connection member and the third electrical connection member are each made of a metal rod member, and Each of the metal shielding members is fixed to each of the three metal rod members constituting the first electrical connection member, the second electrical connection member and the third electrical connection member, and the metal shielding members prevent the charged particles generated by the cluster ion beam from reaching the first high voltage introduction flange, the second high voltage introduction flange and the third high voltage introduction flange.

7. The gas cluster ion beam device according to claim 6, wherein: Each of the shielding members has a bent shape, a center of which is fixed to the metal bar member, and the bent shape is bent outward from the center to approach a corresponding high voltage introduction flange.

8. The gas cluster ion beam device according to claim 1 or 2, wherein: The independent high voltage power supply is a bipolar high voltage power supply capable of producing both positive and negative outputs.

9. The gas cluster ion beam device according to claim 1 or 2, wherein: The central magnetic field strength of the permanent magnet type magnet is 0.1 T or more, which causes deflection so that SF6 monomer ions in the gas cluster beam containing SF6 extracted from the ion generator at an acceleration voltage of 30 KV do not reach the irradiated substrate.

10. The gas cluster ion beam apparatus according to claim 1, wherein: When the high voltage power supply outputs a positive voltage and the independent high voltage power supply applies a positive high voltage, an output voltage of the high voltage power supply is equal to an output voltage of the independent high voltage power supply.

11. The gas cluster ion beam apparatus according to claim 2, wherein: When the high voltage power supply outputs a positive voltage and the independent high voltage power supply applies a positive high voltage, an output voltage of the high voltage power supply is higher than an output voltage of the independent high voltage power supply.

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