KR19990078443A - Ion implantation apparatus and method, ion beam source, and variable slit mechanism - Google Patents

Abstract

The present invention relates to an ion implantation apparatus and method suitable for implanting ions at low energy, an ion beam source, and a variable slit mechanism that can be used as an acceleration electrode for an ion implantation apparatus. In the present invention, an ion source generates ions in a space where a beam potential is applied, and an acceleration electrode is applied with an acceleration potential lower than the beam potential, thereby pulling and accelerating ions generated in the ion source to generate an ion beam. And a mass spectrometer extracts the desired ions from the ion beam accelerated by the accelerating electrode to discharge an ion beam containing substantially only the desired ions, and the deceleration electrode is halfway between the beam potential and the acceleration potential. A deceleration potential, which is a value, is applied to decelerate the ion beam discharged from the mass spectrometer, and a filter electromagnet extracts ions having desired energy from the ion beam decelerated by the deceleration electrode, thereby generating ions having the desired energy. The ion beam which substantially contains only a bay is discharged. Therefore, divergence of the ion beam can be suppressed, and ions can be implanted with low energy while having excellent controllability.

Description

ION IMPLANTATION APPARATUS AND METHOD, ION BEAM SOURCE, AND VARIABLE SLIT MECHANISM

The present invention relates to an ion implantation apparatus and method and a variable slit mechanism, and more particularly to an ion implantation apparatus and method suitable for implanting ions at low energy, and to a variable slit mechanism that can be used as an acceleration electrode for ion implantation apparatus It is about.

In recent years, since semiconductor integrated circuits have become finer, it is desired to make ion implantation low energy. In a conventional ion implantation apparatus, positive ions generated by an ion source to which a positive potential is applied are pulled by an acceleration electrode to which a ground potential is applied to form an ion beam. . The ion beam is then passed through a mass spectrometer equipped with a deflection magnet to form an ion beam containing only the desired ions. Next, ions are implanted into the substrate by applying an ion beam containing only the desired ions to the semiconductor substrate.

However, when the potential applied to the ion source is low, the energy of the ion beam is also lowered.

In addition, when the potential difference between the ion source and the acceleration electrode is low, it is necessary to narrow the gap therebetween. Between the ion source and the accelerating electrode, a suppression electrode to which a negative potential is applied is disposed in order to prevent the electrons in the beam duct from flowing back into the ion source. As described above, it is difficult to control the positions of the ion source, the suppression electrode, and the acceleration electrode, which are disposed in the narrow space, respectively.

In addition, it is necessary to increase the ion density when using a low energy ion beam to maintain the same current density as the high energy ion beam. In this way, if the ion density of the ion beam is increased, the ion beam diverges due to the repulsive force between the ions.

Since ion beams with low energy make it difficult to ionize the gas present in the beam path, electrons do not stay in the ion path, thereby affecting the neutral state of space charge held by the electrons. Will receive. Thus, the ion beam is divergent.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an ion implantation apparatus capable of implanting ions with low energy with excellent controllability while suppressing divergence of an ion beam.

Another object of the present invention is to provide an ion implantation method capable of implanting ions with low energy with excellent controllability while suppressing divergence of an ion beam.

Another object of the present invention is to provide a variable slit mechanism suitable for use as an acceleration electrode of an ion implantation apparatus.

1 is a schematic view showing an ion implantation apparatus according to a first embodiment of the present invention,

FIG. 2 is a block diagram showing the ion implantation apparatus shown in FIG. 1, a graph showing the potential distribution thereof;

3A and 3B are cross-sectional views and front views of an ion source of the ion implantation apparatus shown in FIG. 1;

4 is a cross-sectional view showing an acceleration unit of an ion generating unit in the ion implantation apparatus shown in FIG. 1;

5 is a cross-sectional view of the reduction unit of the ion implantation apparatus shown in FIG. 1;

6 is a side view downstream of the acceleration electrode and the support mechanism of the ion implantation apparatus shown in FIG.

7 is a cross-sectional view of the acceleration electrode support mechanism of the ion implantation device shown in FIG.

8 is a view showing a power system of the ion implantation apparatus shown in FIG.

9 is a schematic diagram of an ion implantation apparatus according to another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

10 ion generating unit 11 beam duct

15 ion source 30 suppression electrode

40 acceleration electrode 50 mass spectrometer

51: deflection electromagnet 52: decomposition ball

53 beam duct 54 inner shield

55: ground shield 60: reduction unit

61 ground beam duct 62 suppression electrode

63: reduction electrode 64: vacuum pump

70: gas supply unit 80: electronic supply unit

90 beam filter unit 91 deflection electromagnet

92: slit 93: ground beam duct

95 ion implantation chamber 96 semiconductor substrate

120 mass spectrometer 121 deflection electromagnet

In order to achieve the above object, an ion implantation apparatus according to an embodiment of the present invention, the ion source for generating ions in the space to which the beam potential is applied; An acceleration electrode applied with an acceleration potential lower than the beam potential to draw and accelerate ions generated in the ion source to form an ion beam; A mass spectrometer for extracting desired ions from the ion beam accelerated by the accelerating electrode and emitting an ion beam substantially containing only the desired ions; A deceleration electrode receiving a deceleration potential, which is an intermediate value between the beam potential and the acceleration potential, to decelerate the ion beam discharged from the mass spectrometer; And a filter electromagnet for extracting ions having desired energy from the ion beam decelerated by the deceleration electrode and discharging an ion beam substantially containing only the ions having the desired energy.

According to one embodiment described above, an ion beam having low energy can be formed by slowing down the ion beam that has passed through the mass spectrometer. Since the energy of the ion beam before passing through the mass spectrometer is relatively high, the divergence of the ion beam can be suppressed. Further, after the ion beam is decelerated, only the ions having the desired energy can be extracted using the filter electromagnet to remove ions that have not been decelerated to the desired energy or excessively decelerated ions during deceleration.

An ion implantation method according to another embodiment of the present invention comprises the steps of: emitting a first ion beam having a first energy; Extracting desired ions from the first ion beam to form a second ion beam substantially containing only the desired ions; Slowing the second ion beam to form a third ion beam; Extracting ions with the desired energy from the third ion beam, and injecting a fourth ion beam containing substantially only the ions with the desired energy into the substrate to be processed.

An ion beam source according to another embodiment of the present invention comprises: an arc chamber defining an ion generating cavity elongated in one direction; A filament disposed almost in the one direction in the ion generating cavity to generate hot electrons; Ion source material introduction means for introducing an ion source material into the ion generating cavity; A magnet for generating a magnetic field in said one direction within said ion generating cavity; It is formed through the side wall of the arc chamber, and when viewed from the front side comprises a beam discharge slit extending in the one direction.

According to another embodiment described above, by arranging the filament almost in the center of the ion generating cavity, the hot electrons generated in the filament can be efficiently used.

According to another embodiment of the present invention, a variable slit mechanism includes a vacuum container; First and second slit defining members disposed on both sides of the slit to define a slit extending from the xy plane of the xyz rectangular coordinate system set for the vacuum container in the x-axis direction; A first support member having an internal cavity extending outwardly of the vacuum container and fixed to the first slit defining member; A second support member secured to said second slit defining member and extending into said inner cavity through a wall of said first support member; Vacuum bellows which prevent the air from leaking through the passage region where the second support member extends through the wall of the first support member; And a slit width variable mechanism for movably supporting the second support member in the inner cavity of the first support member in a y-axis direction with respect to the first support member.

According to this another embodiment, since the inner cavity of the first support member is outward of the vacuum vessel, the slit width can be changed by operating the slit width variable mechanism externally.

An ion implantation apparatus according to another embodiment of the present invention includes an ion source for generating ions in a space to which a beam potential is applied; An acceleration electrode applied with an acceleration potential lower than the beam potential to draw and accelerate ions generated in the ion source to form an ion beam; A mass spectrometer for extracting desired ions from the ion beam accelerated by the accelerating electrode and emitting an ion beam substantially containing only desired ions; A deceleration electrode receiving a deceleration potential, which is an intermediate value between the beam potential and the acceleration potential, to decelerate the ion beam discharged from the mass spectrometer; A first voltage shield member disposed on the acceleration electrode so as to surround a path of the ion beam accelerated by the acceleration electrode and receiving the acceleration potential; And a second voltage shield member surrounding the first voltage shield member and receiving a ground potential.

According to this further embodiment, the first voltage shield member is arranged to surround the ion beam. Therefore, it is not necessary to cover the entire ion source, so that the apparatus can be miniaturized.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic view showing an ion implantation apparatus according to an embodiment of the present invention. The ion implantation apparatus of this embodiment is composed of an ion beam generating unit 10, a mass spectrometer 50, a deceleration unit 60, a beam filter unit 90, and an ion implantation chamber 95. These components define the beam path 1.

The ion beam generating unit 10 is composed of an ion source 15, a suppression electrode 30, and an acceleration electrode 40. These components are arranged in the beam duct 11 which is grounded. The interior of the beam duct 11 is exhausted by the turbo molecular pump 12. The potential of the ion source 15 is set to the beam potential V _B , and the ion beam source 15 generates ions having potential energy corresponding to the beam potential V _B.

The acceleration electrode 40 receives an acceleration potential (-V _A ) lower than the beam potential V _B , for example, -20 kV. The suppression electrode 30 receives a suppression potential (-V _A -V _S1 ) lower by a potential V _S1 , for example, 1800 V, than the potential (-V _A ) of the acceleration electrode. The ions generated in the ion source 15 are attracted by the acceleration electrode 40 to form an ion beam moving along the beam path 1. The suppression electrode 30 prevents electrons generated in the beam duct from returning to the ion source 15.

The mass spectrometer 50 is composed of a deflection electromagnet 51, a resolving aperture 52, a beam duct 53, an inner shield 54, and a ground shield 55. The ion beam emitted from the ion beam generating unit 10 moves in the beam duct, and the moving direction thereof is deflected by the deflecting electromagnet 51. Here, the radius of curvature of the beam trajectory is expressed as a function of ion mass, charge amount and energy. Therefore, only the desired ions pass through the decomposition hole 52 disposed downstream of the deflection electromagnet 51. In this way, an ion beam containing substantially only the desired ions is formed. Here, the term "substantially" means that impurity ions are excluded to the extent that impurity ions other than the desired ions are implanted into the semiconductor substrate so as not to cause problems in the operation of the semiconductor element formed.

The potential of the beam duct 53 is equal to the acceleration potential (-V _A ). Therefore, the inside of the beam path from the acceleration electrode 40 to the decomposition hole 52 is maintained at the acceleration potential (-V _A ). The deflection electromagnet 51 and its power source and the like are arranged inside the inner shield 54 to which a potential (-V _A ) is applied. The inner shield 54 is disposed in the ground shield 55.

The ion beam passing through the decomposition hole 52 enters the reduction unit 60. The ion beam entering the deceleration unit 60 enters the beam filter unit 90 via the suppression electrode 62, the deceleration electrode 63, the gas supply unit 70, and the electron supply unit 80. These components are arranged in the ground beam duct 61. The interior of the ground beam duct 61 is exhausted by the vacuum pump 64.

The suppression electrode 62 receives a suppression potential (-V _A -V _S2 ) lower by a potential V _S2 , for example, 1800 V, than the potential (-V _A ) of the acceleration electrode, and the electrons in the mass spectrometer 50 The movement to the beam path of the deceleration unit 60 is prevented. The deceleration electrode 63 receives a deceleration potential V _D. In this embodiment, the deceleration potential V _D is equal to the ground potential.

The moving direction of the ion beam emitted from the deceleration unit 60 is deflected by the deflection electromagnet 91 of the beam filter unit 90. Here, the radius of curvature of the beam trajectory is expressed as a function of ion mass, charge amount and energy. Thus, only ions with the desired energy enter the ion implantation chamber 95 through the slit 92 disposed downstream of the deflection electromagnet 91. The beam path in the beam filter unit 90 is surrounded by a ground beam duct 93.

The semiconductor substrate 96 to be ion implanted is disposed in the ion implantation chamber 95. As the ion beam entering the ion implantation chamber 95 is irradiated onto the semiconductor substrate 96, ions are implanted into the semiconductor substrate 96.

In the following description, the xyz rectangular coordinate system in which the z axis corresponds to the moving direction of the ion beam and the x axis corresponds to the upward vertical direction is used.

2 is a block diagram showing the ion implantation apparatus shown in FIG. The ion source 15 is applied with a positive beam potential (V _B ), the suppression electrode 30 is applied with a negative suppression potential (-V _A -V _S1 ), the acceleration The electrode 40 receives a negative acceleration potential (-V _A ).

The potential of the beam path from the acceleration electrode 40 to the decomposition hole 52 is maintained at the acceleration potential (-V _A ). The suppression electrode 62 receives a negative suppression potential (-V _A -V _S2 ), and the deceleration electrode 63 receives a ground potential. The potential of the beam path 1 on the downstream side of the deceleration electrode 63 is maintained at the ground potential.

The single charged ions emitted from the ion source 15 and passing through the acceleration electrode 40 have a kinetic energy of e (V _A + V _B ), where e is a charged unit. The single charged ions passing through the deceleration electrode 63 have kinetic energy of eV _B. Thus, ions with kinetic energy eV _B are implanted into the semiconductor substrate.

The beam speed at the upstream side of the deceleration electrode 63 is faster than the beam speed after deceleration, and the ion density at the upstream side of the deceleration electrode 63 is lower than the ion density after deceleration even if the beam current is the same. The ion beam has a kinetic energy of e (V _A + V _B ) large enough to ionize the gas in the beam path. Accordingly, it is possible to hold electrons in the beam path, and to make the space charge neutral. Therefore, the divergence of the beam can be suppressed.

The ion beam before entering the mass spectrometer 50 contains a large amount of ions different from the desired ions. For example, when a B ⁺ ion beam is used, the number of B ⁺ ions is approximately 20% of the total number of ions before entering the mass spectrometer 50. Therefore, the ion density of the ion beam before entering the mass spectrometer 50 is high, thereby causing the ion beam to diverge. On the downstream side of the deceleration electrode 63, since the ion beam contains only desired ions, the ion density is relatively low. Therefore, the divergence propensity of the ion beam is weak on the downstream side of the reduction electrode 63.

Since the kinetic energy of the ion beam is set high in the region where the beam divergence propensity is strong, the beam divergence can be effectively suppressed.

The gas supply unit 70 supplies inert gases such as AR and Xe to the beam path on the downstream side of the reduction electrode 63. The gas ionizes upon collision with the ion beam, generating electrons to make the space charge neutral. The ionized gas ions collide with the walls of the beam duct and become neutral.

The electron supply unit 80 emits electrons in the beam path. These electrons make the space charge in the beam path neutral. When electrons generated by ionization of the gas supplied from the gas supply unit 70 are insufficient, electrons are supplied from the electron supply unit 80 to suppress beam divergence. The same electron supply unit as the electron supply unit 80 may be disposed downstream of the beam filter unit 90.

After only the desired ions are extracted by the mass spectrometer 50, some of these ions are in a neutral state, whereby ions having a charge amount different from the desired charge amount are formed. Such ions are not reduced to the desired energy or are over decelerated by the deceleration electrode 63. That is, the ion beam passing through the deceleration electrode 63 contains particles having energy different from the desired energy, in particular particles in a neutral state and not decelerated properly.

The beam filter unit 90 extracts only ions having desired energy from the ion beam. Thus, it is possible to obtain an ion beam containing substantially only ions with the desired energy.

3A and 3B are cross-sectional views and front views of the ion source of the ion implantation apparatus 15 shown in FIG. The arc chamber 16 defines an ion generating cavity 17 that is long in the x axis. The arc chamber 16 is made of Mo, for example. The tungsten (W) filament 18 is disposed approximately in the center along the x axis in the ion generating cavity 17. The filament 18 emits hot electrons in the ion generating cavity 17. Ion source material introduction tubes 19 and 20 are connected to the arc chamber 16. The ion source material introduction tube 19 supplies the source gas evaporated from the solid source material to the ion generating chamber 17, and the ion source material introduction tube 20 supplies the gas source material in a gas state at room temperature. do.

Magnets 21 are arranged near both ends of the arc chamber 16. The magnet 21 generates a magnetic field along the x-axis direction in the ion generating cavity 17.

A beam discharge slit 22 is formed on the front wall of the arc chamber 16. As seen from the front, the beam discharge slit 22 extends in the x-axis direction and does not extend in the region where the filament 18 is located. Thus, the beam exit slit 22 is composed of a pair of sub-slits that are separated at approximately the center of the front wall.

When viewed along the lateral direction perpendicular to the x-axis direction, that is, along the y-axis direction, the sub slits of the beam slit 22 are slightly inclined in a direction opposite to the direction parallel to the x-axis direction. This inclination direction is set such that the virtual straight lines perpendicular to the sub slits intersect with each other on the outside of the ion generating cavity 17 in the xy plane.

Electron reflecting members 25 are disposed at both ends of the ion generating cavity 17. The electron reflecting member 25 is in an electrically floating state. The hot electrons emitted from the filament 18 move along the positive and negative x-axis directions while turning in the electric field in the x-axis direction. These hot electrons are charged on the electron reflection member 25, and thus the potential of the electron reflection member 25 is lowered. When the potential of the electron reflection member 25 is lowered, hot electrons moving in the x-axis direction are reflected by a potential barrier formed by the electron reflection member 25. In this way, electrons are accumulated in the ion generating cavity 17. Here, the electron reflection member 25 is electrically biased.

The ion source gas introduced into the ion generating cavity 17 is ionized by electrons, thereby generating ions. The ions generated in the ion generating cavity 17 are extracted from the beam emitting slit 22 by the electric field generated near the beam emitting slit 22.

Since the beam discharge slit 22 is slightly inclined with respect to the x-axis direction, the direction of the electric field in the vicinity of the beam discharge slit 22 is slightly inclined with respect to the z direction of the xz plane. Therefore, the pair of ribbon-shaped ion beams discharged from the pair of sub slits gradually become close to each other as they move along the z-axis direction, thereby forming a single ribbon-shaped ion beam.

In the ion source shown in Fig. 3A, the filament 18 is disposed almost in the center of the ion generating cavity. In the filament 18, hot electrons are emitted in about the same amount in the positive and negative x-axis directions. When the filament 18 is disposed on one side of the opposite end of the ion generating cavity 17, only about half of the hot electrons can be used. As shown in FIG. 3A, by arranging the filament 18 near the center of the ion generating cavity 17 in the x-axis direction, the utilization efficiency of hot electrons can be improved.

4 is a cross-sectional view parallel to the yz plane of the acceleration unit of the ion generating unit 10. The suppression electrode 30 is disposed along the xy plane facing the ion source 15. The acceleration electrode 40 is disposed slightly downstream of the suppression electrode 30. The suppression electrode 30 and the acceleration electrode 40 are made of, for example, stainless steel or graphite. The suppression electrode 30 is spaced apart from the acceleration electrode 40 by an insulating spacer 33 made of alumina, boron nitride (BN), or the like. The suppression electrode 30 and the acceleration electrode 40 are each formed with slits parallel to the x-axis. The ribbon-shaped ion beam discharged from the ion source 15 passes through the slit.

The acceleration electrode 40 is supported by the acceleration electrode support arms 42A and 42B in the beam duct 11. This support mechanism will be described later in detail with reference to FIGS. 6 and 7.

The tubular first voltage shield member 41 extends downstream from the acceleration electrode 40. The first voltage shield member 41 is made of, for example, stainless steel and surrounds the path of the ion beam accelerated by the acceleration electrode 40. The first voltage shield member 41 receives the same acceleration voltage (-V _A ) as the acceleration electrode 40 to shield the ion beam from the ground potential of the beam duct 11.

The second voltage shield member 53a is arranged to surround the path of the ion beam passing through the first voltage shield member 41. The second voltage shield member 53a is made of, for example, aluminum or stainless steel, and is provided in the beam duct 53 of the mass spectrometer 50 to have the same potential as that of the beam duct 53.

The second voltage shield member 53a is arranged such that the region near the ion beam introduction end thereof overlaps with the region near the ion beam discharge end of the first voltage shield member 41 in the z-axis direction. In the xy plane, the second voltage shield member 53a is arranged to surround the first voltage shield member 41 in a predetermined space therebetween. Therefore, a ring space 34 is formed between the region near the ion beam discharge end of the first voltage shield member 41 and the region near the ion beam introduction end of the second voltage shield member 53a. It is.

The electron reflecting member 32 is disposed along the ring space 34. The electron reflection member 32 is connected to the suppression electrode 30 through the support rod 31, and the support rod 31 is such that the electron reflection member 32 has the same potential as the suppression electrode 30. It extends to the suppression electrode 30 through the acceleration electrode 40. The electron reflecting member 32 prevents electrons inside the second voltage shield member 53a from leaking through the ring space 34.

The inner cavity of the second voltage shield member 53a is separated from the inner cavity of the beam duct 53 by the gate valve 56. On the upstream side of the gate valve 56, a protective member 57 made of graphite is disposed slightly apart from the gate valve 56. The protection member 57 prevents the ion beam moving away from the beam path from colliding with the inner wall of the beam duct.

The space between the ground duct 11 and the beam duct 53 to which the acceleration voltage (-V _A ) is applied is prevented from leaking air by, for example, an insulating member 58 made of epoxy resin.

FIG. 5 is a cross-sectional view parallel to the yz plane of the reduction unit 60 shown in FIG. 1. The third voltage shield member 52a extends downstream from the beam duct 53 along the ion beam path. The decomposition hole 52 is disposed at the downstream end of the third voltage shield member 52a. The decompression hole 52 is provided with a second suppression electrode 62 via an insulating spacer 62a. The second suppression electrode 62 receives a second suppression potential (-V _A -V _B2 ) through the lead wire 62b.

By applying a potential (-V _A ) to the mass spectrometer 50, the second voltage shield member 53a and the third voltage shield member 52a, the ion beam is maintained in a state where the beam duct 11 is maintained at ground potential. Can accelerate and decelerate. Since the whole of the ion source 15 is not required to be covered with the potential (-V _A ) by using the shield member, the device can be made compact and simple.

A deceleration electrode 63 is disposed slightly downstream of the second suppression electrode 62, and a gas supply unit 70 is disposed downstream of the deceleration electrode 63. The gas supply unit 70 includes a tubular beam path defining member 71 extending downstream from the deceleration electrode 63 and a gas supply pipe 72 connected to the beam path defining member 71. It is. The gas supply pipe 72 extends to the outside through the wall of the beam duct 61. The passage area where the gas supply pipe 72 extends through the wall is prevented from leaking air by the vacuum bellows 73.

Gas is supplied from the gas supply pipe to the internal cavity of the beam path defining member 71 to make the space charge neutral. The reduction electrode 63 is supported in the beam duct 61 by the gas supply pipe 72 and the beam path defining member 71.

An electron supply unit 80 is disposed downstream of the gas supply unit 70. The electron supply unit 80 is composed of a tubular beam path defining member 82, a plasma chamber 83, and a filament 81 installed inside the plasma chamber 83. The inner cavity of the plasma chamber 83 and the beam path inside the beam path defining member 82 are connected to each other through slits.

An inert gas such as Ar is supplied to the plasma chamber 83 through the gas introduction part 84. When hot electrons are emitted from the filament 81, Ar ions and electrons are generated in the plasma chamber 83. The generated Ar ions and electrons are transferred to the beam path through the slit. In this way, electrons can be supplied to the beam path.

6 is a cross-sectional view of the accelerating electrode 40 and the accelerating electron supporting mechanism thereof viewed from the downstream along the z axis. The acceleration electrode 40 is separated into first and second slit defining members 40A and 40B. The slit through which the ion beam passes is defined between the first and second slit defining members 40A and 40B.

At the side of the ion beam path, a first support member 100 having an internal cavity is arranged. The first slit defining member 40A is fixed to the first supporting member 100 through the acceleration electrode supporting arm 42A. The second support member 101 extends from the interior cavity of the first support member 100 through the wall to the interior cavity of the beam duct 11. The passage region through which the second support member 101 extends through the wall is made free from air leakage by the first vacuum bellows 103.

The slit width variable mechanism 102 is disposed in the inner cavity of the first support member 100. The slit width varying mechanism 102 supports the second support member 101 so as to be movable along the y-axis direction with respect to the first support member 100. The second slit defining member 40B is fixed to the second supporting member 101 through the acceleration electrode supporting arm 42B.

As the second support member 101 moves along the y-axis direction parallel to the first support member 100, the width of the slit defined by the first and second slit defining members 40A and 40B is Change.

7 is a cross-sectional view parallel to the yz plane of the support mechanism of the accelerating electrode 40. The first support member 100 extends through the wall of the beam duct 11 in the z-axis direction, whereby the inner cavity of the first support member 100 passes through the outside of the beam duct 11. The passage region where the first support member 100 extends through the wall is formed by the second vacuum bellows 104 so that air does not leak. Accordingly, it is possible to operate the second support member 101 directly from the outside of the beam duct 11 to drive the second support member 101 in the y-axis direction.

The first support member 100 is provided on the third support member 105 via the y-axis movable member 106 in the outside of the beam duct 11. The y-axis direction movable support mechanism 106 movably supports the first support member 100 along the y-axis direction parallel to the third support member 105.

The third supporting member 105 is disposed on the fourth supporting mechanism 107 through the movable direction supporting mechanism 108 in the θy direction. The θy direction movable support mechanism 108 supports the third support member 105 to be rotatable about the y axis direction with respect to the fourth support member 107.

The fourth supporting member 107 is provided on the beam duct 11 through the z-axis movable member 109. The z-direction movable support member 109 supports the fourth support member 107 to be movable along the z-axis direction parallel to the beam duct 11.

The slit width variable mechanism 102, the y-axis movable support mechanism 106 and the z-direction movable support mechanism 109 are configured using a linear ball bearing, for example. The θy direction movable support mechanism 108 is configured using, for example, a ball bearing.

The third support member 105 has a fixed position with respect to the beam duct 11 in the y-axis direction. Therefore, by driving the y-axis direction movable support mechanism 106, the acceleration electrode 40 shown in FIG. 1 can be moved in the y-axis direction. In this way, the moving direction of the ion beam can be changed in the yz plane.

By driving the θy-direction movable support mechanism 108, the acceleration electrode 40 can be inclined with respect to the y-axis direction. By tilting the acceleration electrode 40 in this way, the moving direction of the ion beam can be changed in the xz plane. When the acceleration electrode 40 is inclined, in order not to change the position of the acceleration electrode 40 in the z-axis direction, the rotational center axis of the θy-direction movable support mechanism 108 is a slit of the acceleration electrode 40. It is desirable to set to pass through the center of.

By driving the z axis direction movable support mechanism 109, it is possible to change the position of the acceleration electrode 40 and the suppression electrode 30 provided on the acceleration electrode in the z axis direction. The distance between the ion source 15 and the suppression electrode 30 shown in FIG. 4 can be adjusted according to the acceleration voltage and the beam current.

8 is a diagram illustrating an example of a power system of the ion implantation apparatus shown in FIG. 1. The ion source 15 is connected via a switch SW1 to a positive terminal of a DC power supply DC2 having a voltage V _{B1 or} to a positive terminal of a DC power supply DC3 having a voltage V _B2 . The negative of the DC power supply DC2 is grounded. The negative electrode of the DC power source DC3 is connected to the negative electrode of the DC power source DC1 having the voltage (-V _A ) or the ground potential through the switch SW2. The positive electrode of the DC power supply DC1 is grounded.

The acceleration electrode 40, the beam duct 53 and the decomposition hole 52 are connected to the switch SW2. As the contacts of the switch SW2 are switched, a voltage (-V _A ) or a ground potential is applied to the acceleration electrode 40, the beam duct 53, and the decomposition hole 52.

The DC power supply DC4 applies a voltage (-V _S1 ) to the suppression electrode 30 with respect to the acceleration electrode 40. The DC power supply DC5 applies a voltage (-V _S2 ) to the suppression electrode 62 with respect to the decomposition hole 52. The ground potential is applied to the deceleration electrode 63 and the ion implantation chamber 95.

For example, when ions are implanted at a high energy of about 100 keV, the switch SW2 is switched to the ground potential side, and the switch SW1 is switched to the DC power supply DC2 side. That is, the ion beam forming current is supplied from the DC power supply DC2. Therefore, the DC power supply DC2 needs a maximum output voltage of 100 kV or more.

For example, when ions are implanted at a low energy of about 5 keV, the switch SW2 is switched to the DC power supply DC1 side, and the switch SW1 is switched to the DC power supply DC3 side. That is, the ion beam forming current is supplied from the serial connection of the direct current power source DC1 and the direct current power source DC3. In this case, the voltages V _B2 -V _A become 5 kV.

In general, it is difficult to accurately output a low voltage of about 5 kV using a power supply having a maximum output voltage of about 100 kV. Therefore, in the present invention, by separately installing the low energy power source (DC3) and high energy power source (DC2) as the ion beam forming power source, it is possible to precisely control the energy of the ion beam through the entire range from low energy to high energy have.

In addition, since the maximum output voltage of the DC power supply DC3 is low, the maximum output power can be kept low even when a relatively large current is used. Therefore, a power source having a relatively small power capacity can be used as the direct current power source DC3.

9 is a schematic diagram of an ion implantation apparatus according to another embodiment of the present invention. The ion beam generator unit 10, the deflection electromagnet 51, the decomposing hole 52, the deceleration unit 60, and the filtering deflection electromagnet 91 constitute an ion beam path in almost the same way as the ion implanter shown in FIG. do. The ion implantation apparatus of this embodiment includes another mass spectrometer 120.

When the deflection electromagnet 51 is not driven, the ion beam goes straight into the another mass spectrometer 120. The deflection electromagnet 121 of this mass spectrometer 120 defines an orbit with a larger radius of curvature than the deflection electromagnet 51. That is, the mass spectrometer 120 is suitable for high energy ion beams. The ion beam passing through the mass spectrometer 121 enters a magnetic field generated by the deflection electromagnet 91. In this case, the ion beam does not pass through the reduction unit 60.

For example, when injecting ions at a high energy of about 20 keV or more, the mass spectrometer 120 is driven. For example, when injecting ions at low energy of about 20 keV or less, the mass spectrometer 50 and the deceleration unit ( 60). In this way, ions can be implanted through the entire range from low energy to high energy.

On the other hand, the present invention is not limited to the above preferred embodiments, it can be carried out by various modifications and modifications within the scope not departing from the gist of the present invention.

As described above, according to the present invention, the ion beam having a low energy can be formed by slowing down the ion beam passing through the mass spectrometer, and the ion beam diverges because the energy of the ion beam before passing through the mass spectrometer is relatively high. And decelerating the ion beam, and by using the filter electromagnet to extract only the ions having the desired energy, ions not decelerated to the desired energy or excess decelerated ions can be removed during deceleration. have.

Further, by arranging the filament almost in the center of the ion generating cavity, the hot electrons generated in the filament can be efficiently used. In addition, since the inner cavity of the first support member passes through the outside of the vacuum container, the slit width can be changed by operating the slit width variable mechanism from the outside. In addition, since the first voltage shield member surrounds the ion beam, it is not necessary to cover the entire ion source, so that the apparatus can be miniaturized.

Claims (21)

An ion source for generating ions in the space to which the beam potential is applied; An acceleration electrode applied with an acceleration potential lower than the beam potential to draw and accelerate ions generated in the ion source to form an ion beam; A mass spectrometer for extracting desired ions from the ion beam accelerated by the accelerating electrode and emitting an ion beam substantially containing only the desired ions; A deceleration electrode receiving a deceleration potential, which is an intermediate value between the beam potential and the acceleration potential, to decelerate the ion beam discharged from the mass spectrometer; An ion implantation comprising a filter electromagnet extracting ions with desired energy from the ion beam decelerated by the deceleration electrode and discharging an ion beam substantially containing only the ions with the desired energy Device. The method of claim 1, The deceleration potential is an ion implantation device, characterized in that the ground potential. The method of claim 1, It further comprises a first suppression electrode disposed between the ion source and the acceleration electrode, And the first inhibitory electrode has a passage area through which ions pulled out of the ion source pass, and receives a potential lower than the acceleration potential. The method of claim 1, It further comprises a second suppression electrode disposed between the mass spectrometer and the deceleration electrode, And the second suppression electrode is formed to have a passage area through which ions discharged from the mass spectrometer pass, and receives a potential lower than the acceleration potential. The method of claim 1, And a gas supply means for supplying gas to a path of the ion beam between the deceleration electrode and the filter electromagnet. The method of claim 1, And an electron supply means for supplying electrons to a path of the ion beam between the deceleration electrode and the filter electromagnet. The method of claim 1, A first voltage shield member disposed on the acceleration electrode and surrounding a path of the ion beam accelerated by the acceleration electrode, And the first voltage shield member receives the acceleration potential. The method of claim 7, wherein And a second voltage shield member surrounding the path of the ion beam between the first voltage shield member and the mass spectrometer, The ion beam introduction end of the second voltage shield member and the ion beam discharge portion of the first voltage shield member are disposed with a space in a direction orthogonal to the moving direction of the ion beam, And the second voltage shield member receives the acceleration potential. The method of claim 8, And an electron reflecting member disposed in a space portion between the ion beam introduction end of the second voltage shield member and the ion beam discharge portion of the first voltage shield member. And the electron reflecting member receives a potential lower than the acceleration potential. The method of claim 1, Another mass for extracting the desired ions from the ion beam introduced after being accelerated by the accelerating electrode and introducing an ion beam containing substantially only the desired ions to the filter electromagnet when the mass spectrometer is not driven. An ion implantation device, characterized in that further comprises a spectrometer. Emitting a first ion beam having a first energy; Extracting desired ions from the first ion beam and forming a second ion beam containing substantially only the desired ions; Slowing the second ion beam to form a third ion beam; Extracting ions with desired energy from the third ion beam and implanting a fourth ion beam containing substantially only the ions with the desired energy into the substrate to be processed. Injection method. An arc chamber defining a long ion generating cavity in one direction; A filament disposed near the center of the one direction in the ion generating cavity to generate hot electrons; Ion source material introduction means for introducing an ion source material into the ion generating cavity; A magnet for generating a magnetic field in said one direction within said ion generating cavity; An ion beam source formed through a sidewall of the arc chamber and including a beam discharge slit extending in one direction when viewed from the front side thereof. The method of claim 12, And an electron reflecting member disposed at both inner ends of the ion generating cavity and set in an electrically floating state. The method of claim 13, And the beam exit slit is divided into a pair of sub slits at a position corresponding to a position where the filament is disposed. The method of claim 14, The pair of sub slits are inclined in opposite directions with respect to the one direction, An imaginary straight line perpendicular to each sub slit of the sub slit pair crosses each other outside the ion generating cavity when viewed along a lateral direction perpendicular to the one direction. A vacuum container; First and second slit defining members disposed on both sides of the slit to define a slit extending in the x-axis direction of the xy plane of the xyz rectangular coordinate system set for the vacuum container; A first support member having an internal cavity extending outwardly of the vacuum container and fixed to the first slit defining member; A second support member secured to said second slit defining member and extending into said inner cavity through a wall of said first support member; A vacuum bellow which prevents air from leaking in the passage area where the second support member extends through the wall of the first support member; And a slit width variable mechanism for movably supporting the second support member in the y-axis direction with respect to the first support member in the inner cavity of the first support member. . A vacuum container; A slit defining member for defining a slit extending in the x-axis direction of the xy plane of the xyz rectangular coordinate system set for the vacuum container; A support member extending out of the vacuum vessel through a wall of the vacuum vessel; A vacuum bellows which prevents air from leaking in the passage area where the support member extends through the wall of the vacuum vessel; And a y-axis moveable support mechanism for supporting the support member so as to be movable in the y-axis direction with respect to the vacuum container from the outside of the vacuum vessel. The method of claim 17, And a z-axis direction movable support mechanism for supporting the support member so as to be movable in a z-axis direction with respect to the vacuum container on the outside of the vacuum container. The method of claim 17, And a θy direction movable support mechanism for rotatably supporting the support member on the outside of the vacuum vessel about a y axis with respect to the vacuum vessel. An ion source for generating ions in the space to which the beam potential is applied; An acceleration electrode applied with an acceleration potential lower than the beam potential to draw and accelerate ions generated in the ion source to form an ion beam; A mass spectrometer for extracting desired ions from the ion beam accelerated by the accelerating electrode and emitting an ion beam substantially containing only the desired ions; A deceleration electrode receiving a deceleration potential, which is an intermediate value between the beam potential and the acceleration potential, to decelerate the ion beam discharged from the mass spectrometer; A first voltage shield member provided on the acceleration electrode and receiving the acceleration potential so as to surround a path of the ion beam accelerated by the acceleration electrode; And a second voltage shield member surrounding the first voltage shield member and receiving a ground potential. The method of claim 20, The deceleration potential is an ion implantation device, characterized in that the ground potential.