JP2949102B1 - Beam generator - Google Patents

Abstract

An object of the present invention is to provide a low-cost beam generating apparatus capable of generating various beams capable of performing efficient pre-processing on a sample. A beam generating device includes a chamber and a first electrode arranged in order along a Z-axis direction. The chamber 10 has a structure in which a first filament 16a for generating an ion beam or a second filament 16b for generating an electron beam can be fitted to one end face along the Z axis, and the other end face along the Z axis. And a focusing electrode 14. A first filament 16a is attached to one end surface of the chamber 10, a positive ion plasma is generated in the chamber 10, and an ion beam is emitted by applying an acceleration voltage of + VA between the chamber 10 and the first electrode 20. You.
The electron beam is emitted by attaching the second filament 16b to the chamber 10 and applying an acceleration voltage of -VA between the chamber 10 and the second electrode 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a beam generator, and more particularly to a beam generator for generating an electron beam or an ion beam for performing a predetermined process on a sample.

[0002]

2. Description of the Related Art In the field of various research and development, particularly in the field of basic research such as analysis of atomic arrangement on a metal surface and structural analysis of atoms, various types of beams such as an electron beam and an ion beam are used in accordance with each experimental theme. Is indispensable. An electron beam generator that generates an electron beam is used for pretreatment such as heating a sample such as a metal, removing impurities attached to the sample, and neutralizing a positive charge. In addition, an ion beam generator that generates an ion beam is used for pretreatment such as cleaning a sample before depositing another metal on a sample surface such as various metals or performing analysis of the sample surface. You.

[0003]

Incidentally, these electron beam generators and ion beam generators are each constituted by a separate casing. These housings are incorporated in each unit. Therefore, when continuously irradiating a sample with an electron beam and an ion beam, it is necessary to move the sample between a unit having an electron beam generator and a unit having an ion beam generator. is there.

[0004] Further, since both the electron beam generator and the ion beam generator are expensive, if both are required, a huge budget is required for capital investment. As described above, conventionally, since the electron beam generator and the ion beam generator are each configured in a separate casing, a sample that needs to be continuously irradiated with the electron beam and the ion beam is transferred between the units. There is a problem that it takes time and effort to move the sample, and pretreatment such as cleaning cannot be efficiently performed on the sample. Further, there is a problem that a huge budget is required to purchase the electron beam generator and the ion beam generator.

The present invention has been made in view of the above-mentioned problems, and provides a low-cost beam generating apparatus capable of generating various beams capable of performing efficient pre-processing on a sample. The purpose is to do.

[0006]

In order to solve the above-mentioned problems and achieve the object, a beam generating apparatus according to claim 1 is provided.
A first filament section for generating an ion beam;
Alternatively, a chamber capable of attaching a second filament part for generating an electron beam to one end thereof, a focusing electrode attached to the other end of the chamber and having an opening, and a focusing electrode provided adjacent to the focusing electrode. An accelerating electrode arranged in a manner as described above, a plasma generating means for generating plasma in the chamber when the first filament portion is attached to the chamber, and a plasma generating means for attaching the first filament portion to the chamber. A voltage for forming a first potential difference between the focusing electrode and the accelerating electrode, in order to discharge plasma generated in the chamber by the plasma generating means from an opening of the focusing electrode. A first voltage supply means for supplying the second filament part to the chamber; A second voltage supply means for supplying a voltage for forming a second potential difference between the focusing electrode and the accelerating electrode to the focusing means in order to emit electrons generated in the focusing section from the opening of the focusing electrode. And characterized in that:

[0007]

According to a fifth aspect of the present invention, there is provided a beam generating apparatus, wherein a first filament portion for generating an ion beam or a second filament portion for generating an electron beam can be attached to one end of the chamber; A heat shield plate attached to the other end of the chamber and having a first opening for shielding heat generated in the chamber; and a heat shield plate when superimposed on the heat shield plate. A focusing electrode provided with a second opening corresponding to the first opening, and a concave portion for forming a gap between the heat shielding plate and the focusing electrode, and disposed adjacent to the focusing electrode. An accelerating electrode having a ground potential, plasma generating means for generating plasma in the chamber when the first filament portion is attached to the chamber, and the first filament portion being installed in the chamber. When attached, the focusing is performed so that plasma generated in the chamber by the plasma generating means is emitted from a second opening of the focusing electrode through a first opening of the heat shield plate. A first voltage for supplying a voltage that forms a positive potential difference between the electrode and the acceleration electrode with respect to the acceleration electrode at a ground potential to the focusing means;
When the second filament section is attached to the chamber, electrons generated from the second filament section are supplied to the second electrode of the focusing electrode via the first opening of the heat shield plate when the second filament section is attached to the chamber. A second voltage supply unit that supplies a voltage that forms a negative potential difference with respect to the ground potential acceleration electrode to the focusing unit, between the focusing electrode and the acceleration electrode, in order to release the light from the opening. It is characterized by having.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a beam generating apparatus according to an embodiment of the present invention. First,
The ion beam generator will be described.

FIG. 1 is a diagram schematically showing the configuration of an ion beam generator. That is, as shown in FIG. 1, the ion beam generator includes a chamber 1 for generating plasma.
0, a first electrode 20 functioning as an acceleration electrode, a second electrode 30, and a third electrode 40. The chamber 10, the first electrode 20, the second electrode 30, and the third electrode 40 are arranged in order along the Z-axis direction from which the ion beam is emitted, and are adjacent to each other at a predetermined interval. It is arranged.

A chamber 10 has a gas inlet 11 into which an inert gas such as argon gas or nitrogen gas is introduced, a ring-shaped anode ring 12 having a circular opening centered on the Z axis, and a coil for emitting thermoelectrons. Filament 13
a, and a Wehnelt 14 functioning as a focusing electrode disposed on an end face along the Z-axis.

The anode ring 12 is insulated from the chamber 10. One end of the filament 13a is insulated from the chamber 10 and the other end is electrically connected to the chamber 10. The Wehnelt 14 has an opening 15 for emitting positive ions as plasma generated inside the chamber 10. The Wehnelt 14 is electrically connected to the chamber 10 and has the same potential as the chamber 10. As shown in FIG. 1, the opening 15 of the Wehnelt 14 has a sectional shape inclined at a predetermined angle with respect to the Z axis.
The inner diameter of the opening 15, that is, the opening diameter facing the inside of the chamber 10, is formed to be smaller than the outer diameter of the opening 15, that is, the opening diameter of the surface facing the first electrode 20.

The first electrode 20 is disposed adjacent to the chamber 10 at a predetermined interval, and has a Z
It has a circular opening 21 centered on the axis. The second electrode 30 is disposed adjacent to the first electrode 20 at a predetermined interval, and has a circular opening 31 centered on the Z axis. The third electrode 40 is arranged adjacent to the second electrode 30 at a predetermined interval, and has a circular opening 41 centered on the Z axis.

A potential difference V is applied to both ends of the filament 13a.
A filament voltage forming F is applied. The anode ring 12 has a potential difference + VDS with respect to the chamber 10.
Is applied. An acceleration voltage that forms a potential difference + VA between the chamber 10 and the grounded first electrode 20 is applied to the chamber 10. Second electrode 30
To the first electrode 20 and the third electrode 40, which are grounded, are applied with a focusing voltage that forms a potential difference + VL.

In the ion beam generator having such a configuration, first, an inert gas, for example, an argon gas is introduced into the chamber 10 from the gas inlet 11. At this time, a current is passed through the filament 13a to heat the filament 13a, and electrons are emitted toward the anode ring 12 having a potential of + VDS. Filament 13
The electrons emitted from a vibrate between the vicinity of the anode ring 12 and the filament 13a. With this electron,
The argon gas introduced into the chamber 10 is ionized, and a high-temperature plasma composed of positive argon ions is generated. Since the argon ions have a positive charge, they are accumulated near Wehnelt 14.

When an acceleration voltage + VA is applied between the Wehnelt 14 and the first electrode 20, positive argon ions flow from the opening 15 of the Wehnelt 14 to the first electrode 20.
It is released toward.

Further, a focusing lens is formed by a potential difference formed between the first electrode 20 and the second electrode 30 and between the second electrode 30 and the third electrode 40, and a predetermined focusing property is provided. The emitted ion beam is emitted along the Z-axis direction.

An ion beam generator for generating an ion beam is constructed based on the above principle. Next, the electron beam generator will be described.

FIG. 2 is a diagram schematically showing the configuration of the electron beam generator. Note that the same components as those of the ion beam generator shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

That is, the electron beam generator has basically the same configuration as the ion beam generator, and includes a chamber 10 which is sequentially arranged at a predetermined distance from each other along the Z-axis direction, Third electrodes 20, 30, and 40 are provided. The chamber 10 has a gas inlet 11 for introducing an inert gas, a ring-shaped anode ring 12 having a circular opening centered on the Z axis, a filament 13b for emitting thermoelectrons, and along the Z axis. It has a Wehnelt 14 functioning as a focusing electrode disposed on the end face. However, when the chamber 10 is used as an electron beam generator, no inert gas is introduced from the gas inlet 11 and no voltage is applied to the anode ring 12.

When used as an electron beam generator, the filament 13b is formed in a V shape having a tip 13c protruding to the vicinity of an opening 15 formed in Wehnelt 14.

A voltage having a potential difference VF is applied to both ends of the filament 13b. Further, the chamber 10 includes:
An acceleration voltage that forms a potential difference -VA with the grounded first electrode 20 is applied. A focusing voltage that forms a potential difference -VL between the grounded first electrode 20 and third electrode 40 is applied to the second electrode 30.

In the electron beam generator having such a configuration, first, a current is supplied to the filament 13b in the chamber 10 to heat the filament 13b.
Electrons are emitted. The electrons emitted from the filament 13 b are focused by the Wehnelt 14 by applying an acceleration voltage −VA between the Wehnelt 14 and the first electrode 20, and the electrons emitted from the opening 15 of the Wehnelt 14
It is emitted toward the electrode 20.

Further, a focusing lens is formed by a potential difference formed between the first electrode 20 and the second electrode 30 and between the second electrode 30 and the third electrode 40, and a predetermined focusing property is provided. The emitted electron beam is emitted along the Z-axis direction.

An electron beam generator for generating an electron beam is constructed based on the above principle. By the way, the beam generating apparatus of the present invention makes use of the configuration of the ion beam generating apparatus as shown in FIG. And a configuration capable of reversing the polarity of the voltage applied to.

That is, this beam generating apparatus has a structure to which either one of a first filament portion having a filament for generating an ion beam and a second filament portion having a filament for generating an electron beam can be attached. And a plurality of electrodes. Further, the beam generating apparatus includes a first driving circuit as first voltage supply means for supplying a voltage for generating an ion beam to the chamber and each electrode, and a first driving circuit for supplying a voltage for generating an electron beam to the chamber and each electrode. 2nd voltage supply means
A drive circuit. The chamber and each electrode of this beam generator have the basic structure of the ion generator.

In this beam generating apparatus, the first filament section is attached to the chamber, and a predetermined voltage is applied to the chamber and each electrode by the first drive circuit, so that the apparatus is used as an ion beam generating apparatus for generating an ion beam. It is possible to Further, in this beam generating device, the second filament portion is attached to the chamber, and a predetermined voltage is applied to the chamber and each electrode by the second drive circuit, so that the beam generating device can be used as an electron beam generating device for generating an electron beam. It is possible.
These first drive circuit and second drive circuit can be switched by a switch.

FIG. 3 is a diagram schematically showing the configuration of the beam generating apparatus of the present invention. FIG. 3 shows a configuration in a case where the beam generator is used for generating an ion beam.

That is, as shown in FIG. 3, the beam generating device comprises a cylindrical chamber 10 arranged in order at a predetermined interval along the Z-axis direction, and a first electrode 20.
, A second electrode 30, and a third electrode 40. The first electrode 20, the second electrode 30, and the third electrode 40 have circular openings 21, 31, and 41, respectively, centered on the Z axis.

FIG. 4 is an enlarged view showing the structure of a chamber provided with a first filament section for generating an ion beam.
FIG. 5 shows a first end of the chamber for generating an ion beam.
It is an exploded perspective view at the time of attaching a filament part.

As shown in FIGS. 3 to 5, a cylindrical chamber 10 has a gas inlet 11 for introducing an inert gas, and a ring-shaped anode having a circular opening centered on the Z axis. A ring 12 is provided. The anode ring 12 functions as a plasma generation unit. The cylindrical chamber 10 has one end face along the Z axis,
A first filament portion 16a provided with a coiled filament 13a for emitting thermoelectrons for generating an ion beam, or a second filament portion 16b provided with a V-shaped filament 13b for emitting thermoelectrons for generating an electron beam Has a structure that can be attached. 3 to 5 show:
An example in which the first filament portion 16a is attached to one end surface of the chamber 10 is shown. Further, the chamber 10
Has a Wehnelt 14 functioning as a focusing electrode on the other end surface along the Z-axis.

The anode ring 12 is insulated from the chamber 10 as shown in FIG. As shown in FIGS. 3 and 4, the Wehnelt 14 has a circular opening 15 centered on the Z axis. This Wehnelt 14
Is electrically connected to the chamber 10 and has the same potential as the chamber 10. The opening 15 of the Wehnelt 14
It has a cross-sectional shape inclined at a predetermined angle with respect to the Z axis. That is, the inner diameter of the opening 15 is formed to be smaller than the outer diameter of the opening 15. Opening 15
The inclination angle with respect to the Z axis in the cross section is set to an appropriate angle in accordance with the required focusing performance.

As shown in FIGS. 3 to 5, the first filament portion 16a is a circular insulating support portion 17 which engages with one end surface of the chamber 10, and a metal provided on the inner surface of the support portion 17. The first introduction line 19A is connected to one end of the filament 13a for generating an ion beam through the plate 18 and the support plate 17, and is connected to multiple ends of the filament 13a through the support plate 17 and the metal plate 18. Second introduction line 19
B is provided. The first introduction line 19A is insulated from the support 7 and the chamber 10, and the second introduction line 19B is electrically connected to the chamber 10 via the metal plate 18.

The first filament portion 16 having such a structure
As shown in FIG. 5, a is inserted into one end surface of the chamber 10, and is fixed by the C-ring 51 after the support plate 17 is fitted to a predetermined position of the chamber 10. Further, FIG.
As shown in the figure, the support plate 1 of the first filament portion 16a
7 is screwed and fixed to the chamber 10 by screws.

FIG. 6 is an enlarged view showing the structure of a chamber provided with a second filament section for generating an electron beam. As shown in FIG. 6, the configuration of the second filament portion 16b for generating an electron beam is the same as that of the first filament portion 16a except that the shape of the filament 13b is different. The same reference numerals are given and the detailed description is omitted.

That is, in order to generate an electron beam using the ion beam generating chamber 10, it is necessary to extend the tip of the filament 13 b to the vicinity of the opening 15 formed in the Wehnelt 14. For this reason,
The filament 13b of the second filament portion 16b is formed in a V-shape having a tip 13c protruding to the vicinity of the opening 15 formed in the Wehnelt 14. This tip 13c corresponds to the apex angle of the V-shaped filament 13b.

The second filament portion 16 having such a structure
b is fixed to the chamber 10 by the C ring 51 and the screw 52 in the same manner as the first filament portion 16a.
Subsequently, a first driving circuit for generating an ion beam will be described.

As shown in FIG. 3, when the first filament portion 16a for generating an ion beam is attached to the chamber 10, the first introduction line 19A of the first filament portion 16a is connected to the first filament power supply. The second lead-in line 19B is connected to the terminal TF1 and is connected to the second
Connected to terminal TF2. The second introduction line 19 </ b> B is connected to the chamber 10 via the metal plate 18. And
A filament voltage having a potential difference VF is applied to both ends of the filament 13a. The filament voltage is, for example, 1
It is set so that the current is 0 V and a current of 4 A flows.

The anode ring 12 insulated from the chamber 10 is connected to a first terminal TD of a discharge power supply.
1 and the chamber 10 is connected to a second terminal TD2 of the discharge power supply. Then, a discharge voltage for forming a potential difference + VDS with respect to the chamber 10 is applied to the anode ring 12. The discharge voltage is, for example, + 100V.

The acceleration power supply has a first terminal TA1 and a second terminal TA2 having a potential difference of, for example, 500 V.
When generating an ion beam, the switch SW is switched to the terminal TI, the second terminal TA2 of the acceleration power supply is grounded, and a voltage of +500 V is output from the first terminal TA1. The terminal T1 is connected to the terminal T in conjunction with the switch SW.
2 and the terminal T3 is connected to the terminal T4. Thereby, the first electrode 2 that is grounded is provided in the chamber 10.
For 0, an acceleration voltage of a first potential difference + VA, that is, +500 V is applied from the first terminal TA1 of the acceleration power supply.

The second electrode 30 is connected to a first terminal TA of the acceleration power supply.
It is connected to a terminal TL capable of setting an arbitrary potential between the potential difference between the first and second terminals TA2. That is, in the example shown in FIG. 3, the potential can be set to an arbitrary value within a range of 0 to +500 V, but is set to a substantially intermediate potential, for example, 300 V
Is set to The second electrode 30 is applied with a second potential difference + VL, that is, a focusing voltage of +300 V, between the grounded first electrode 20 and the third electrode 40.

In the beam generating apparatus having such a configuration, first, an inert gas is introduced into the chamber 10 through the gas inlet 11 and an electric current is caused to flow through the filament 13a to emit electrons from the heated filament 13a. . Then, high-temperature plasma composed of positive ions is generated in the chamber 10.

By applying an accelerating voltage between the Wehnelt 14 having the same potential as the chamber 10 and the first electrode 20, positive ions are emitted from the opening 15 of the Wehnelt 14 toward the first electrode 20. You.

Further, a focusing lens is formed by a potential difference formed between the first electrode 20 and the second electrode 30 and between the second electrode 30 and the third electrode 40, and a predetermined focusing property is provided. The emitted ion beam is emitted along the Z-axis direction.

Next, a second drive circuit for generating an electron beam will be described. As shown in FIG. 6, when the second filament section 16b for generating an electron beam is attached to the chamber 10, the first introduction line 19A of the second filament section 16b is connected to the first terminal TF1 of the filament power supply. And the second introduction line 19B is connected to the second terminal TF2 of the filament power supply. Then, a filament voltage having a potential difference VF is applied to both ends of the filament 13b. The filament voltage is, for example, 10
V, and is set so that a current of 4 A flows.

The output from the first terminal TD1 of the discharge power supply connected to the anode ring 12 is set to 0V. The accelerating power supply has a first potential difference of, for example, 500 V.
A terminal TA1 and a second terminal TA2 are provided. To generate an electron beam, the switch SW is switched to the terminal TE, the first terminal TA1 of the acceleration power supply is grounded,
A voltage of -500 V is output from the terminal TA2. Also,
In conjunction with the switch SW, the terminal T1 is connected to the terminal T5, and the terminal T3 is connected to the terminal T6. Thereby, the potential difference -VA, that is, -V, from the second terminal TA2 of the acceleration power source to the grounded first electrode 20 is provided in the chamber 10.
An acceleration voltage of 500 V is applied.

The second electrode 30 is connected to a first terminal TA of the acceleration power supply.
It is connected to a terminal TL capable of setting an arbitrary potential between the potential difference between the first and second terminals TA2. That is, in the example shown in FIG. 3, the potential can be set to an arbitrary potential within the range of -500 V to 0 V, but is set at a substantially intermediate potential, for example, -30
It is set to 0V. The second electrode 30 is applied with a potential difference of −VL, that is, a focusing voltage of −300 V, between the grounded first electrode 20 and third electrode 40.

In the beam generating apparatus having such a configuration, first, electrons are emitted from the heated filament 13b by applying a current to the filament 13b without introducing an inert gas into the chamber 10.

The electrons emitted from the filament 13b are focused by the Wehnelt 14 by applying an accelerating voltage between the Wehnelt 14 and the first electrode 20, and are transferred from the opening 15 of the Wehnelt 14 to the first electrode 20. Released toward.

Further, a focusing lens is formed by a potential difference formed between the first electrode 20 and the second electrode 30, and between the second electrode 30 and the third electrode 40, and a predetermined focusing property is given. The emitted electron beam is emitted along the Z-axis direction.

As described above, according to this beam generator, the filament is exchanged, and the drive circuit suitable for the exchanged filament is selected, so that the ion beam and the electron beam can be selectively produced in one housing. Can be generated. That is, the beam generator can function as an ion beam generator that generates an ion beam or an electron beam generator that generates an electron beam.

Therefore, it is possible to eliminate the trouble of moving a sample which needs to be continuously irradiated with an electron beam and an ion beam between units, and to perform an efficient pretreatment on the sample. Becomes In addition, since one housing can be shared without separately purchasing an ion beam generator and an electron beam generator,
A beam generator capable of generating an electron beam and an ion beam can be provided at low cost.

Next, a preferred embodiment applied when this beam generator is used as an ion beam generator will be described. That is, when the Wehnelt provided at the other end of the chamber is made of, for example, a single metal plate made of stainless steel, it is easily deteriorated by high-temperature plasma of several thousand degrees generated inside the chamber, There is a problem that the heat retention of the plasma is poor. Therefore, the ionization efficiency of the inert gas introduced into the chamber is low, and a high output cannot be obtained. To solve this problem, it is conceivable to apply a large current to the filament to generate more thermoelectrons, but the life of the filament is shortened accordingly.

Therefore, in the beam generator according to this embodiment, the Wehnelt has a double structure. That is, as shown in FIG. 7, the other end of the chamber 10 from which the ion beam is emitted is provided with a circular first metal plate 14 </ b> A facing the inside of the chamber 10 and the outside of the chamber 10, that is, the first electrode 20. There is provided a Wehnelt 14 having a double structure composed of the opposed circular second metal plate 14B.

The first metal plate 14A is formed of, for example, a metal such as molybdenum (Mo), tantalum (Ta), or tungsten (W), and functions as a heat-resistant heat shielding plate. The first metal plate 14A has a circular first opening 15a centered on the Z axis.

The second metal plate 14B is made of, for example, stainless steel. The second metal plate 14B has a circular second opening 15b centered on the Z axis.
The second opening 15b has a cross-sectional shape such that the outer diameter facing the first electrode 20 is larger than the inner diameter facing the first metal plate 14A. The second metal plate 14b functions substantially as a focusing electrode.

The second metal plate 14b is, as shown in FIG.
It has a U-shaped cross section. That is, a concave portion is formed on the surface of the second metal plate 14B facing the first metal plate 14A. Therefore, when the first metal plate 14A is superimposed on the surface of the second metal plate 14B having the concave portion,
A gap 1 between the metal plate 14A and the concave portion of the second metal plate 14B
4C is formed. The width of the gap 14C is, for example, 0.
2 to 0.3 mm.

The Wehnelt 14, composed of the first metal plate 14A and the second metal plate 14B,
4A faces the inside of the chamber 10 and the recess of the second metal plate 14B is in contact with the first metal plate 14A.
Of the chamber 1 by the C-ring 53.
Fixed to 0.

In such a Wehnelt 14 having a double structure,
By supplying a voltage, for example, +500 V, that forms a positive potential difference to the acceleration electrode 20 at the ground potential, the plasma of the positive ions generated inside the chamber 10 is converted to the first opening 15a of the first metal plate 14A. The ion beam is formed by discharging the light from the second opening 15b of the second metal plate 14B through the hole.

With such a structure, deterioration of the Wehnelt 14 itself can be prevented by the first metal plate 14A as a heat shield plate having excellent heat resistance, and the first metal plate 14A and the second metal plate 14B It is possible to improve the heat retention of the plasma reaching several thousand degrees due to the gap 14C. Therefore, the inert gas can be efficiently ionized without passing a large current through the filament, and an ion beam with a relatively high output can be obtained. Further, since it is not necessary to supply a large current to the filament, the life of the filament is about twice as long as the case where the Wehnelt is formed of one metal plate.

When the discharge current supplied to the anode ring is 30 mA and the Wehnelt 14 is formed of one metal plate, the output of the ion beam is 5.8.
In contrast to μA, when Wehnelt 14 has a double structure, it is 12.9 μA, and the output can be improved about twice or more.

As described above, according to this beam generator, a heat-resistant heat shielding plate facing the inside of the chamber and a focusing electrode for focusing the electron beam emitted from the inside of the chamber are provided on the other end surface of the chamber. By applying a double-layered Wehnelt equipped, the deterioration of the Wehnelt itself due to plasma generated in the chamber can be prevented, the service life can be prolonged, and a welt formed between the heat shield plate and the focusing electrode can be formed. The gap provided makes it possible to improve the heat retention in the chamber, and to efficiently generate plasma even with low power consumption. Therefore, it is possible to obtain high ion beam output with low power consumption. What
The concept of the heat shield plate of the present invention is
With a coiled filament that emits electrons for
Gas for introducing inert gas
A cylindrical chamber with a gas inlet,
When attached to one end, one end of the chamber
And the gas inlet
Generates plasma by ionizing inert gas introduced from
Coiled filament that emits electrons to form
And provided inside the chamber,
Anode for focusing electrons emitted from the filament
And attached to the other end of the chamber.
A first opening, wherein heat generated in the chamber is provided.
A heat shielding plate that shields, when superposed on the heat shielding plate
A second opening corresponding to the first opening of the heat shield plate;
Part, for forming a gap between the heat shield plate
A focusing electrode having a recess formed therein, adjacent to the focusing electrode;
A ground potential accelerating electrode and a
The formed plasma is passed through a first opening of the heat shield plate.
In order to release the light from the second opening of the focusing electrode,
The acceleration of the ground potential is provided between the focusing electrode and the acceleration electrode.
A voltage that forms a predetermined potential difference with respect to the electrodes is
And voltage supply means for supplying the voltage to the poles.
Beam generating device.

[0063]

As described above, according to the present invention, it is possible to provide a low-cost beam generating apparatus capable of generating various beams capable of performing efficient pre-processing on a sample.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a configuration of an ion beam generator.

FIG. 2 is a diagram schematically showing a configuration of an electron beam generator.

FIG. 3 is a diagram schematically showing a configuration of a beam generating device of the present invention.

FIG. 4 is a sectional view schematically showing a structure of a chamber to which a first filament portion is attached when the beam generator shown in FIG. 3 is used as an ion beam generator.

FIG. 5 is an exploded perspective view of the chamber and the first filament section shown in FIG. 4;

FIG. 6 is a cross-sectional view schematically showing a structure of a chamber to which a second filament portion is attached when the beam generating device shown in FIG. 3 is used as an electron beam generating device.

FIG. 7 is a cross-sectional view schematically showing a Wehnelt structure applied to the beam generating device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Chamber 11 ... Gas inlet 12 ... Anode ring 13 (a, b) ... Filament 14 ... Wehnelt 14A ... Heat shield plate 14B ... Focusing electrode 14C ... Gap 15 ... Opening 16a ... 1st filament part 16b ... 2nd filament Part 17: Support plate 18: Metal plate 19 (A, B) ... Introductory line 20: First electrode 30 ... Second electrode 40 ... Third electrode 51, 53 ... C ring 52 ... Screw

Claims (4)

(57) [Claims] 1. A chamber to which a first filament portion for generating an ion beam or a second filament portion for generating an electron beam can be attached at one end, and which is attached to the other end of the chamber. Along with
A focusing electrode having an opening, an accelerating electrode arranged adjacent to the focusing electrode, and plasma generating means for generating plasma in the chamber when the first filament part is attached to the chamber. When the first filament part is attached to the chamber, the focusing electrode and the accelerating electrode are used to discharge plasma generated in the chamber by the plasma generating means from an opening of the focusing electrode. A first voltage supply unit for supplying a voltage that forms a first potential difference to the focusing unit, and an electron generated from the second filament unit when the second filament unit is attached to the chamber. In order to emit the light from the opening of the focusing electrode, a voltage that forms a second potential difference between the focusing electrode and the acceleration electrode is applied to the focusing electrode. A second voltage supply means for supplying the bundle means to the bundle means. 2. The accelerating electrode is grounded, and the first voltage supply means supplies a voltage for forming a first positive potential difference to the focusing means with respect to the acceleration electrode at a ground potential, 2. The beam generating apparatus according to claim 1, wherein the second voltage supply unit supplies a voltage forming a negative second potential difference to the focusing unit with respect to the ground electrode of the acceleration electrode. 3. 3. The first filament section includes a coil-shaped filament disposed at a position close to one end side of the chamber when attached to one end of the chamber, and the second filament section. Comprises a V-shaped filament having an apex angle disposed near an opening of the focusing electrode attached to the other end of the chamber when attached to one end of the chamber. The beam generator according to claim 1, wherein 4. A chamber capable of attaching a first filament section for generating an ion beam or a second filament section for generating an electron beam to one end, and being attached to the other end of the chamber. Along with
A heat shield plate that has a first opening and shields heat generated in the chamber; and a second shield corresponding to the first opening of the heat shield plate when superimposed on the heat shield plate. A focusing electrode having an opening, and a concave portion for forming a gap between the heat shielding plate, a ground potential accelerating electrode disposed adjacent to the focusing electrode, A plasma generating unit that generates plasma in the chamber when one filament unit is attached; and a plasma generating unit that is generated in the chamber by the plasma generating unit when the first filament unit is attached to the chamber. In order to discharge the plasma from the second opening of the focusing electrode through the first opening of the heat shielding plate, between the focusing electrode and the accelerating electrode, the plasma is discharged with respect to the accelerating electrode at the ground potential. Positive A first voltage supply unit for supplying a voltage for forming a potential difference to the focusing unit; and, when the second filament unit is attached to the chamber, an electron generated from the second filament unit is supplied to the heat shielding plate. A voltage that forms a negative potential difference between the focusing electrode and the accelerating electrode with respect to a ground potential accelerating electrode for emission from the second opening of the focusing electrode through the first opening; And a second voltage supplying means for supplying the voltage to the focusing means.