JP2008108745A - Neutral particle beam treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charge-free and damage-free neutral particle beam treatment device which can radiate beams of large diameters to a treatment object and can obtain a high neutralization ratio by an economical and compact constitution. <P>SOLUTION: The neutral particle beam treatment device is provided with a holding part 20 to hold a treatment object X, a plasm generating part which repeats alternately the application and stop of a high-frequency voltage and generates plasma containing positive ions and negative ions in a vacuum chamber 3, an orifice electrode 4 which is placed in the vacuum chamber and arranged between the plasma generating part and the treatment object and shields ultraviolet rays emitted from the plasma, a grid electrode 5 arranged in an upper stream with respect to the orifice electrode in the vacuum chamber, and a bipolar power source 102 which applies a voltage between the orifice electrode and the grid electrode and takes out alternately the positive ions and the negative ions from the plasma generated in the plasma generating part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a neutral particle beam processing apparatus, and more particularly to a neutral particle beam processing apparatus that generates a high-directivity and high-density particle beam from high-density plasma and processes an object to be processed.

  In recent years, processing patterns have been remarkably miniaturized in fields such as semiconductor integrated circuits, information storage media such as hard disks, and micromachines. In processing in this field, a technology for performing film formation or etching of an object to be processed by irradiating an energy beam such as a high-density ion beam with a relatively large diameter and high straightness (high directivity) Is attracting attention.

  As such an energy beam source, one that generates various beams such as positive ions, negative ions and radical particles is known. By irradiating such a beam of positive ions, negative ions, radical particles, etc. from the beam source to any part of the object to be processed, local film formation or etching of the object to be processed, surface modification, bonding, adhesion And so on.

  In a beam source that irradiates an object to be processed with charged particles such as positive ions and negative ions, an insulator cannot be processed (charge-up phenomenon) because charges accumulate on the object to be processed. Further, since the ion beam diverges due to the space charge effect, fine processing cannot be performed.

  In order to prevent this, it is considered to neutralize the charge by injecting electrons into the ion beam. However, although this method can balance the overall charge, there is a local charge imbalance. After all, I can not do fine processing.

  In addition, when ions are extracted from the plasma source and irradiated on the object to be processed, the object to be processed is adversely affected if the object is irradiated with radiation light such as ultraviolet rays generated from the plasma. It is necessary to shield emitted light such as ultraviolet rays.

  The present invention has been made in view of such problems of the prior art, and is capable of irradiating a workpiece with a large-diameter beam with an inexpensive and compact configuration and obtaining a high neutralization rate. An object of the present invention is to provide a neutral particle beam processing apparatus that is charge-free and damage-free.

  In order to solve such a problem in the prior art, one embodiment of the present invention includes a holding unit that holds an object to be processed, and an application of a high-frequency voltage and a stop of the application alternately. A plasma generating unit that generates plasma containing positive ions and negative ions in the vacuum chamber; and an ultraviolet ray that is disposed in the vacuum chamber between the plasma generating unit and the object to be processed and is emitted from the plasma. By applying a voltage between the orifice electrode to be shielded, the grid electrode disposed upstream of the orifice electrode in the vacuum chamber, and the orifice electrode and the grid electrode, A bipolar power source for alternately extracting positive ions and negative ions from the generated plasma, and positive ions from the plasma by the bipolar power source. A neutral particle beam processing apparatus characterized in that negative ions are alternately extracted and passed through an orifice formed in the orifice electrode to neutralize the positive ions and the negative ions in the orifice. is there.

  In a preferred aspect of the present invention, the apparatus further includes a modulation device that synchronizes the application timing of the high-frequency voltage and the application timing of the voltage by the bipolar power supply.

  According to the present invention, it is possible to extract positive ions and negative ions alternately, neutralize them, and irradiate the workpiece as a neutral particle beam. Since the object to be processed can be processed by a neutral particle beam having no charge and large translational kinetic energy, highly accurate etching and film formation can be performed while keeping the charge-up amount small. In this case, two types of treatment can be performed alternately by alternately irradiating neutral particles resulting from neutralization of positive ions and neutral particles resulting from neutralization of negative ions.

  Hereinafter, a first embodiment of a beam processing apparatus according to the present invention will be described in detail with reference to FIGS. 1 to 3. FIG. 1 is a diagram showing an overall configuration of a beam processing apparatus according to the first embodiment of the present invention.

  As shown in FIG. 1, the beam processing apparatus has a cylindrical shape having a beam generating chamber 1 for generating a neutral particle beam and a processing chamber 2 for processing an object to be processed X such as a semiconductor substrate, glass, organic matter, and ceramics. The vacuum chamber 3 is provided. In the vacuum chamber 3, the beam generation chamber 1 side is made of quartz glass or ceramic, and the processing chamber 2 side is made of a metal metal chamber.

  An inductively coupled coil 10 is disposed on the outer periphery of the beam generation chamber 1. The coil 10 is a coil of a water-cooled pipe, for example, and a coil having an outer diameter of about 8 mmφ is wound around the beam generation chamber 1 for about two turns. The coil 10 is connected to a high frequency power source 101 via a matching box 100, and a high frequency voltage of 13.56 MHz is applied to the coil 10, for example. The coil 10, the matching box 100, and the high frequency power source 101 constitute a plasma generation unit. That is, an induction magnetic field is generated by passing a high-frequency current through the coil 10, and atoms and molecules in the gas are ionized by the displacement current to generate plasma.

A gas introduction port 11 for introducing gas into the vacuum chamber 3 is provided in the upper part of the beam generation chamber 1, and this gas introduction port 11 is connected to a gas supply source 13 via a gas supply pipe 12. . A gas such as SF ₆ , CHF ₃ , CF ₄ , Cl ₂ , Ar, O ₂ , N ₂ , C ₄ F _8, etc. is supplied from the gas supply source 13 into the vacuum chamber 3.

  In the processing chamber 2, a holding unit 20 that holds the workpiece X is disposed, and the workpiece X is placed on the upper surface of the holding unit 20. The processing chamber 2 is provided with a gas discharge port 21 for discharging gas. The gas discharge port 21 is connected to a vacuum pump 23 via a gas discharge pipe 22. The processing chamber 2 is maintained at a predetermined pressure by the vacuum pump 23.

  An orifice plate (orifice electrode) 4 made of a conductor such as graphite is disposed at the lower end of the beam generating chamber 1, and the orifice electrode 4 is set to the ground potential. The orifice electrode 4 functions as a first electrode and neutralizing means. Further, above the orifice electrode 4, a thin grid-like grid electrode (second electrode) 5 which is also formed of a conductor is disposed. The grid electrode 5 is connected to a bipolar power source 102 (voltage application unit). For example, a low frequency voltage of 400 kHz is applied to the grid electrode 5 by the bipolar power source 102. FIG. 2 is a perspective view (FIG. 2A) and a partial longitudinal sectional view (FIG. 2B) of the orifice electrode 4 and the grid electrode 5. As shown in FIG. 2, the orifice electrode 4 has a large number of orifices 4a, and the grid electrode 5 has a large number of grid holes 5a. The grid electrode 5 may be a mesh net or punching metal.

  Modulators 103 and 104 are connected to a high-frequency power source 101 and a bipolar power source 102 connected to the coil 10, respectively. The high-frequency power source 101 and the bipolar power source 102 are connected to each other via the modulation devices 103 and 104, and the timing of voltage application by the high-frequency power source 101 and the voltage application by the bipolar power source 102 are determined by a synchronization signal between the modulation devices 103 and 104. Timing is synchronized.

Next, the operation of the beam processing apparatus in this embodiment will be described. FIG. 3 is a time chart showing an operation state in the present embodiment. In FIG. 3, Va is the potential of the coil 10, Te is the electron temperature in the beam generating chamber 1, ne is the electron density of the beam in the generating chamber 1, ni ^- the negative ion density in the beam generating chamber 1, Vb grid electrode 5 potentials are shown. Note that the time chart of FIG. 3 is schematic, and for example, the illustrated period is different from the actual period.

First, after evacuating the inside of the vacuum chamber 3 by operating the vacuum pump 23, SF ₆ , CHF ₃ , CF ₄ , Cl ₂ , Ar, O ₂ , N ₂ , C ₄ F _{8 is} supplied from the gas supply source 13. Or the like is introduced into the vacuum chamber 3. Then, as shown in FIG. 3, a high frequency voltage of 13.56 MHz is applied to the coil 10 by the high frequency power supply 101 for 10 μsec. By applying the high frequency voltage, a high frequency electric field is formed in the beam generating chamber 1. The gas introduced into the vacuum chamber 3 is ionized by electrons accelerated by the high-frequency electric field, and high-density plasma is generated in the beam generation chamber 1. The plasma formed at this time is a plasma mainly composed of positive ions and heated electrons.

  Then, the application of the high frequency voltage by the high frequency power supply 101 is stopped for 100 μsec. After the application of the high-frequency voltage by the high-frequency power supply 101 is stopped, the high-frequency voltage applied by the high-frequency power supply 101 again heats the electrons in the plasma in the beam generation chamber 1 and the above-described cycle is repeated. That is, the application of a high-frequency electric field (10 μsec) and the application stop (100 μsec) are repeated alternately. This high-frequency electric field application stop time (100 μsec) is sufficiently longer than the time required for negative ions to be generated by adhering to the processing gas in which electrons in the plasma remain, and the electron density in the plasma Is sufficiently shorter than the time when the plasma is extinguished and the plasma is extinguished. The application time of the high-frequency electric field (10 μsec) is a time sufficient to recover the energy of the electrons in the plasma that has decreased while the application of the high-frequency electric field is stopped.

  By stopping the application of the high-frequency electric field after increasing the energy of electrons in the plasma, negative ions can be generated efficiently and continuously. That is, normal plasma often consists of positive ions and electrons, but plasma in a state where negative ions coexist with positive ions can be efficiently formed. Although an example in which the application stop time of the high-frequency electric field is set to 100 μs has been described here, a large amount of negative ions as well as positive ions can be generated in the plasma by setting the time to 50 μs to 100 μs. Can do.

  After 50 μsec from the stop of voltage application by the high frequency power supply 101, a low frequency voltage of 400 kHz is applied to the grid electrode 5 by the bipolar power supply 102 for 50 μsec. In this application of the low frequency voltage, when the potential Vb of the grid electrode 5 is higher than the potential (ground potential) of the orifice electrode 4 (for example, the portion indicated by A in FIG. 3), the orifice electrode 4 and the grid electrode 5 A potential difference is generated between the orifice electrode 4 as a cathode and the grid electrode 5 as an anode. Accordingly, positive ions 6 (see FIG. 2B) leaking from the grid electrode 5 toward the orifice electrode 4 are accelerated toward the orifice electrode 4 by this potential difference, and enter the orifice 4a formed in the orifice electrode 4. To go.

  At this time, the positive ions 6 passing through the orifice 4a of the orifice electrode 4 are mainly neutralized in the vicinity of the solid surface of the peripheral wall of the orifice 4a or charge with the gas remaining in the orifice 4a. Neutralized by exchange or neutralized by colliding with electrons emitted from the surface of the orifice electrode 4 and recombining to become neutral particles 7.

  On the other hand, when the potential Vb of the grid electrode 5 is lower than the potential (ground potential) of the orifice electrode 4 (for example, a portion indicated by B in FIG. 3), the orifice electrode 4 is interposed between the orifice electrode 4 and the grid electrode 5. A potential difference is generated using the anode as the anode and the grid electrode 5 as the cathode. Accordingly, negative ions leaking from the grid electrode 5 toward the orifice electrode 4 are accelerated toward the orifice electrode 4 by this potential difference, and enter the orifice 4 a formed in the orifice electrode 4. The negative ions passing through the orifice 4a of the orifice electrode 4 are neutralized mainly in the vicinity of the solid surface of the peripheral wall of the orifice 4a or neutralized by charge exchange with the gas remaining in the orifice 4a. To neutral particles 7. Thus, since the high neutralization rate can be obtained by using the orifice electrode as a means for neutralization, it becomes possible to increase the diameter of the beam inexpensively without increasing the size of the apparatus.

  Positive ions or negative ions (neutral particles) neutralized while passing through the orifice 4a are alternately emitted into the processing chamber 2 as an energy beam. The neutral particles 7 travel straight through the inside of the processing chamber 2 and irradiate the workpiece X placed on the holding unit 20, and the neutral particles 7 cause the surface of etching, cleaning, nitriding treatment, oxidation treatment, etc. It is possible to perform processing such as modification and film formation.

In this way, by alternately irradiating neutral particles resulting from neutralization of positive ions and neutral particles resulting from neutralization of negative ions, two types of treatments can be performed alternately. For example, when the gases introduced into the vacuum chamber 3 are Cl ₂ and Xe, Xe sputtering is performed using Xe due to neutralization of positive ions, and chlorine etching is performed using chlorine due to neutralization of negative ions. Therefore, the etch rate can be increased by the chemical sputtering action.

  In addition, for example, by irradiating a chlorine beam, several atomic layers having a weak binding force between chlorine and the object to be processed are formed. Etching without destroying the crystal structure of the atoms of the workpiece if appropriate reaction process and energy control are performed, such as sputtering removal with Xe beam having energy that cannot cut strong bonding force. Is possible.

  In this case, the orifice electrode functions not only as a means for neutralizing ions, but also as a means for preventing the object to be irradiated with radiation light generated from plasma. That is, since the beam generation chamber 1 where the plasma is generated and the workpiece X are blocked by the orifice electrode 4, the radiation X generated from the plasma is not irradiated on the workpiece X, and the workpiece X is damaged. This can reduce the influence on the object to be processed X such as ultraviolet rays.

  Although some charged particles may also pass through the orifice 4a of the orifice electrode 4, in order to prevent such charged particles from irradiating the workpiece X, the charged particles are disposed downstream of the orifice electrode 4. A deflector or an electronic trap may be provided. The deflector changes the traveling direction of the charged particles by applying a voltage in the radial direction of the vacuum chamber 3 to prevent irradiation of the workpiece X with the charged particles. Further, the electron trap changes the traveling direction of the charged particles by forming a magnetic field in the radial direction, thereby preventing irradiation of the workpiece X with the charged particles.

  When processing insulators such as glass and ceramic materials, there is a problem of charge-up on the surface. By irradiating neutral particles thus neutralized, the amount of charge-up is kept small and high precision is achieved. Etching and film formation are possible. Note that the type of gas may be properly used according to the processing content of the object to be processed. In dry etching, oxygen, halogen gas, or the like can be properly used according to the difference in the object to be processed.

  In the present embodiment, an example in which the grid electrode 5 is disposed on the downstream side of the coil 10 has been described. However, the grid electrode may be disposed on the upstream side of the coil 10. In this case, no holes need be formed in the grid electrode. FIG. 4 is a diagram showing the overall configuration of the beam processing apparatus when the grid electrode 50 is arranged on the upstream side of the coil 10. In this case, positive ions and negative ions in the plasma generated in the beam generation chamber 1 are accelerated between the grid electrode 50 and the orifice electrode 4.

  In the present embodiment, the example in which the orifice electrode is used as the neutralizing means has been described. However, the present invention is not limited to this, and other neutralizing means may be used. For example, (1) neutralization is performed by irradiating ions extracted from plasma with an electron beam, and (2) a region in which neutral gas is introduced by introducing neutral gas onto the extracted ion path. And neutralize the ions by passing through this region, (3) neutralize by irradiating the ions with light, (4) neutralize by shaking the ions with a high-frequency electric field, (5) Various neutralizing means such as forming an electron cloud on the extracted ion path and neutralizing it by passing through the electron cloud can be applied. Further, instead of the orifice electrode, an electrode having a slit or a honeycomb structure may be used.

  Next, a first reference example of the beam processing apparatus will be described in detail with reference to FIGS. In addition, the same code | symbol is attached | subjected to the member or element which has the same effect | action or function as the member or element in the above-mentioned 1st Embodiment, and the part which is not demonstrated in particular is the same as that of 1st Embodiment. FIG. 5 is a diagram illustrating an overall configuration of a first reference example of the beam processing apparatus.

  The vacuum chamber 30 in the present reference example is a metal chamber formed of metal, and includes a thin grid-like grid electrode (second electrode) 8 formed of a conductor on the upstream side of the interior thereof. The vacuum chamber 30 and the grid electrode 8 are electrically connected, and these are at ground potential.

  Further, as shown in FIG. 5, an AC power source 105 and an AC power source 106 are connected to the orifice electrode (first electrode) 4 in parallel. Modulators 107 and 108 are connected to these power supplies 105 and 106, respectively. Further, the modulation device 107 of the AC power supply 105 and the modulation device 108 of the AC power supply 106 can be synchronized with each other by a synchronization signal. These AC power supplies 105 and 106 and modulators 107 and 108 constitute a voltage application unit. The vacuum chamber 30 and the orifice electrode 4 are electrically insulated by an insulator (not shown).

Next, the operation of the beam processing apparatus in this reference example will be described. FIG. 6 is a time chart showing an operation state in this reference example. In FIG. 6, Vc is the potential at the AC power supply 105, Te is the electron temperature in the beam generating chamber 1, ne is the electron density of the beam in the generating chamber 1, ni ^- the negative ion density of the beam generating chamber 1, Vd AC The potential of the power source 106, Ve, indicates the potential of the orifice electrode 4, respectively. Note that the time chart in FIG. 6 is schematic, and for example, the illustrated cycle is different from the actual cycle.

  First, by evacuating the vacuum chamber 30 by operating the vacuum pump 23, gas is introduced from the gas supply source 13 into the vacuum chamber 30. Then, as shown in FIG. 6, a high frequency voltage of 13.56 MHz is applied to the orifice electrode 4 by an AC power source 105 for 10 μsec. By applying the high frequency voltage, a high frequency electric field is formed in the beam generating chamber 1. The gas introduced into the vacuum chamber 30 is ionized by electrons accelerated by the high-frequency electric field, and high-density plasma is generated in the beam generation chamber 1.

  Then, the application of the high frequency voltage by the AC power source 105 is stopped for 100 μsec. After the application of the high frequency voltage is stopped, the electrons in the plasma are heated in the beam generation chamber 1 again by the application of the high frequency voltage for 10 μsec by the AC power source 105, and the above-described cycle is repeated. That is, the application of a high-frequency electric field (10 μsec) and the application stop (100 μsec) are repeated alternately.

  By stopping the application of the high-frequency electric field after increasing the energy of electrons in the plasma, negative ions can be generated efficiently and continuously. That is, normal plasma often consists of positive ions and electrons, but plasma in a state where negative ions coexist with positive ions can be efficiently formed.

  After 50 μs from the stop of voltage application by the AC power source 105, a low frequency voltage of 400 kHz is applied to the orifice electrode 4 by the AC power source 106 for 50 μs. As in the first embodiment, positive ions and negative ions are alternately accelerated toward the orifice electrode 4 by the potential difference due to the low frequency voltage, and enter the orifice 4a formed in the orifice electrode 4. .

  Positive ions or negative ions that pass through the orifice 4a of the orifice electrode 4 are neutralized to become neutral particles in the same manner as in the first embodiment described above, and alternately become neutral particles as an energy beam. To be emitted. The neutral particles travel straight through the inside of the processing chamber 2 and are irradiated to the workpiece X placed on the holding unit 20.

  As described above, in this reference example, by alternately applying a high frequency voltage and a low frequency voltage between the orifice electrode 4 and the grid electrode 8, plasma is generated and positive ions and negative ions are generated from the generated plasma. Can be extracted alternately, and there is no need to provide a separate plasma generation unit for generating plasma. For this reason, the apparatus can be made more compact and the beam diameter can be increased at a low cost.

  Next, a second reference example of the beam processing apparatus will be described in detail with reference to FIGS. In addition, the same code | symbol is attached | subjected to the member or element which has the same effect | action or function as the member or element in the above-mentioned 1st Embodiment, and the part which is not demonstrated in particular is the same as that of 1st Embodiment. FIG. 7 is a diagram illustrating an overall configuration of a second reference example of the beam processing apparatus.

  In the present reference example, the negative ion generation chamber 31a in which electrons adhere to the residual gas and negative ions are generated in the downstream region of the coil 10 of the beam generation chamber 31 is the same as the first embodiment described above. Different. As described above, in this reference example, a so-called downstream type beam processing apparatus in which the negative ion generation chamber 31a is formed in the downstream region of the generated plasma is configured.

  The negative ion generation chamber 31a can be provided with an electron cloud forming means for forming an electron cloud in the negative ion generation chamber 31a as necessary. Specifically, as shown in FIG. 8, permanent magnets 9 are arranged at a predetermined interval in the circumferential direction of the vacuum chamber 3. At this time, the magnetic poles of adjacent permanent magnets 9 are arranged to be opposite. By disposing the permanent magnet 9 in this way, a magnetic field is formed in the vacuum chamber 3 so that electrons in the plasma go around the trajectory indicated by C in FIG. 8, and an electron cloud is formed. Such an electron cloud forming means is not limited to the case of using a permanent magnet, and can also be configured by applying an electric field in the negative ion generation chamber 31a.

  A low frequency power source 109 that applies a low frequency voltage of, for example, 400 kHz is connected to the grid electrode 5. In this reference example, unlike the first embodiment, no modulation device is provided.

  Next, the operation of the beam processing apparatus in this reference example will be described. FIG. 9 is a time chart showing an operation state in this reference example. Vf represents the potential in the coil 10, and Vg represents the potential of the grid electrode 5. Note that the time chart of FIG. 9 is schematic, and for example, the illustrated period is different from the actual period.

First, after evacuating the inside of the vacuum chamber 3 by operating the vacuum pump 23, SF ₆ , CHF ₃ , CF ₄ , Cl ₂ , Ar, O ₂ , N ₂ , C ₄ F _{8 is} supplied from the gas supply source 13. Or the like is introduced into the vacuum chamber 3. Then, as shown in FIG. 9, a high frequency voltage of 13.56 MHz is applied to the coil 10 by the high frequency power source 101. By applying this high frequency voltage, a high frequency electric field is formed in the beam generating chamber 31. The gas introduced into the vacuum chamber 3 is ionized by electrons accelerated by the high-frequency electric field, and high-density plasma is generated in the beam generation chamber 31. The plasma formed at this time is a plasma mainly composed of positive ions and heated electrons.

  As described above, in this reference example, the negative ion generation chamber 31a is provided in the downstream region of the plasma, and in the negative ion generation chamber 31a, electrons having a low electron temperature adhere to the residual gas and negative ions are generated. Generated. Therefore, the negative ion generation chamber 31a is a region where positive ions, negative ions, and electrons exist.

  Simultaneously with the application of the high frequency voltage by the high frequency power supply 101, a low frequency voltage of 400 kHz is applied between the grid electrode 5 and the orifice electrode 4 by the low frequency power supply 109. Similar to the above-described embodiment, positive ions and negative ions in the negative ion generation chamber 31 a are alternately accelerated toward the orifice electrode 4 by the potential difference due to the low frequency voltage, and the orifice 4 a formed in the orifice electrode 4. Enter.

  Positive ions or negative ions that pass through the orifice 4a of the orifice electrode 4 are neutralized to become neutral particles in the same manner as in the first embodiment described above, and alternately become neutral particles as an energy beam. To be emitted. The neutral particles travel straight through the inside of the processing chamber 2 and are irradiated to the workpiece X placed on the holding unit 20.

  Also in this reference example, the grid electrode can be arranged on the upstream side of the coil 10. FIG. 10 is a diagram showing the overall configuration of the beam processing apparatus when the grid electrode 50 is arranged on the upstream side of the coil 10. In this case, positive ions and negative ions in the plasma in the negative ion generation chamber 31 a are accelerated by the voltage applied to the grid electrode 50 and the orifice electrode 4.

  In the embodiment and the reference example described above, an example in which positive ions and negative ions are alternately extracted and neutralized has been described. However, positive ions and negative ions are alternately extracted and neutralized. It is also possible to irradiate the object to be processed as a positive ion beam or a negative ion beam as it is without being converted into a target.

  FIG. 11 is a diagram illustrating an overall configuration in the case where the workpiece X is irradiated alternately with positive ions and negative ions as energy beams without performing neutralization in the first embodiment described above. In the example shown in FIG. 11, a thin grid-type grid electrode (second electrode) 51 formed of a conductor is disposed instead of the orifice electrode. The grid electrode 51 is set to the ground potential similarly to the orifice electrode in the first embodiment. In such a configuration, as in the first embodiment, a high-frequency voltage is applied to the coil 10 by the high-frequency power source 101 for 10 μs to generate high-density plasma in the beam generation chamber 31, and voltage application by the high-frequency power source 101 is performed. When a low-frequency voltage is applied to the grid electrode 51 by the bipolar power source 102 after 50 μs from the stop of this, positive ions and negative ions jump out of the grid electrode 51 alternately and irradiate the workpiece X.

  Similarly, in the embodiment shown in FIG. 4, the reference example shown in FIG. 7, and the reference example shown in FIG. 10, the object X is irradiated alternately with positive ions and negative ions without neutralization. The overall configuration of the apparatus in these cases is shown in FIGS. 12, 13, and 14, respectively.

  In the embodiment and the reference example described above, an example in which plasma is generated using an ICP type coil has been described. It is good to do. Also, the frequency region of the high frequency is not limited to 13.56 MHz, and a region of 1 MHz to 20 GHz may be used. Also, the low frequency range is not limited to 400 kHz. For example, as shown in FIG. 15, a rectangular voltage may be applied instead of the low frequency voltage.

  Although one embodiment of the present invention has been described so far, it is needless to say that the present invention is not limited to the above-described embodiment, and may be implemented in various forms within the scope of the technical idea.

It is a figure which shows the whole structure of the beam processing apparatus in the 1st Embodiment of this invention. It is a figure which shows the orifice electrode and grid electrode which are shown in FIG. 1, and has shown the state by which a positive ion is neutralized especially. It is a time chart which shows the operation state in the 1st Embodiment of this invention. It is a figure which shows the whole structure of the beam processing apparatus in other embodiment of this invention. It is a figure which shows the whole structure of the beam processing apparatus in a 1st reference example. It is a time chart which shows the operation state in the 1st reference example. It is a figure which shows the whole structure of the beam processing apparatus in a 2nd reference example. It is sectional drawing which shows the electron cloud formation means in the 2nd reference example. It is a time chart which shows the operation state in the 2nd reference example. It is a figure which shows the whole structure of the beam processing apparatus in a 3rd reference example. In the 1st Embodiment of this invention, it is a figure which shows the whole structure in the case of irradiating a to-be-processed object with a positive ion and a negative ion alternately, without neutralizing. In the embodiment shown in FIG. 4, it is a figure which shows the whole structure in the case of irradiating a to-be-processed object with a positive ion and a negative ion alternately, without performing neutralization. In a 2nd reference example, it is a figure which shows the whole structure in the case of irradiating a to-be-processed object with a positive ion and a negative ion alternately, without performing neutralization. In the reference example shown in FIG. 10, it is a figure which shows the whole structure in the case of irradiating a to-be-processed object with a positive ion and a negative ion alternately, without neutralizing. It is a time chart which shows an example of the voltage applied instead of a low frequency voltage.

Explanation of symbols

X object to be processed 1,31 beam generation chamber 2 processing chamber 3,30 vacuum chamber 4 orifice electrode (neutralizing means)
4a Orifice 5, 8, 50, 51 Grid electrode 6 Positive ion 7 Neutral particle 9 Permanent magnet (electron cloud formation means)
DESCRIPTION OF SYMBOLS 10 Coil 11 Gas introduction port 12 Gas supply piping 13 Gas supply source 20 Holding | maintenance part 21 Gas discharge port 22 Gas discharge piping 23 Vacuum pump 31a Negative ion production | generation chamber 100 Matching box 101 High frequency power supply 102 Bipolar power supply (voltage application part)
103, 104, 107, 108 Modulator 105 AC power supply (first voltage application unit)
106 DC power supply (second voltage application unit)
109 Low frequency power supply

Claims (2)

A holding unit for holding a workpiece;
A plasma generation unit that generates plasma including positive ions and negative ions in a vacuum chamber by alternately applying high-frequency voltage and stopping application;
An orifice electrode in the vacuum chamber, disposed between the plasma generation unit and the object to be processed, and shielding ultraviolet rays emitted from the plasma;
A grid electrode disposed upstream of the orifice electrode in the vacuum chamber;
A bipolar power source that alternately draws positive ions and negative ions from the plasma generated by the plasma generator by applying a voltage between the orifice electrode and the grid electrode;
The positive ion and the negative ion are neutralized in the orifice by alternately extracting positive ions and negative ions from the plasma through the orifice formed in the orifice electrode by the bipolar power source. Neutral particle beam processing equipment.   2. The neutral particle beam processing apparatus according to claim 1, further comprising a modulation device that synchronizes timing of application of the high-frequency voltage and timing of voltage application by the bipolar power source.

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