JP3096167B2 - Ion implanter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion implantation apparatus.

[0002]

2. Description of the Related Art FIG. 5 schematically shows a conventional ion implantation apparatus. In FIG. 5, a substantially rectangular high voltage terminal 2 is disposed in a shielding case 1 made of metal. For this, a high voltage of, for example, 400 KV is applied by a high voltage generator 16 disposed below the high voltage terminal 2, and an ion source 14 and a mass are provided in the high voltage terminal 2. It has a built-in separation electromagnet 15 and has another known structure.
The high-voltage terminal 2 is supported at a predetermined height on the bottom wall of the shielding casing 1 by four insulating posts 17 as shown by a chain line.

The accelerating pipe 3 and one end of an exhaust pipe 7 are fixed to one side wall of the high voltage terminal 2 in parallel with the accelerating pipe 3, and the other end is fixed to the inner wall surface of the shielding casing 1. Further, one end of a cylindrical bushing 12 is fixed to the other side surface of the high-voltage terminal 2, and the other end is fixed to the other inner wall surface of the shielding casing 1.
An insulating transformer 11 having a withstand voltage of 00 KV is fixed.

As is well known, ions from an ion source 14 disposed in the high voltage terminal 2 receive Lorentz force by a voltage applied to a mass separation magnet 15 and draw a predetermined trajectory based on the Lorentz force. Rush inside. Electrodes 6 are fixed to the outer circumferential surface of the accelerating tube 3 at 90 ° intervals in the circumferential direction and at equal intervals in the length direction, and a ring-shaped metal hoop 5 made of metal is fixed to the outer end surface. Have been. A resistor 4 having a predetermined value is connected between the metal hoops 5. Further, electrodes 8 are also fixed at equal angular intervals on the outer peripheral surface of the exhaust pipe 7 in parallel with the exhaust pipe 7.
Connected by A vacuum pump 10 is fixed to an end of the exhaust pipe 7 fixed to the shielding casing 1.

A metal hoop 19 is fixed at a predetermined interval also on the outer peripheral surface of the bushing 12 fixed to the other side surface of the high-voltage terminal 2.
3 are connected.

The conventional ion implantation apparatus is configured as described above. Next, this operation will be described. In FIG. 5, a gas tank (not shown) that stores a gas of a desired ion is supplied to an ion source 14 where the gas is converted into a plasma, that is, ionized to produce a mass separation magnet 15. Is derived toward. Although the mass separation magnet 15 has a known structure, a predetermined magnetic field is formed by applying a predetermined current to a coil wound around the electromagnet, and ions enter the ion source 14 from the ion source 14. At this time, I received Lorentz force,
The trajectory is bent in the direction of approximately 90 degrees depending on the flow speed of the ion beam and the strength of the magnetic field, and travels toward the acceleration tube 3. Since a high voltage of 400 KV is applied to the high-voltage terminal 2 and the high-voltage terminal 2 is installed in the shielding casing 1, the energy corresponding to the potential difference therebetween, that is, the speed, is obtained, and the vehicle travels in the accelerating tube 3 and is shielded. The ion is injected into the ion processing device from the end of the acceleration tube 3 fixed to the wall 1. The inner space of the ion source 14 and the like is placed under a predetermined reduced pressure via the exhaust pipe 7 by the vacuum pump 10. The insulating transformer 11 supplies electric power necessary for operating the mass separation magnet 15 and the ion source 14.

[0007] The conventional ion implantation apparatus is constructed and operates as described above, but has the following defects.

That is, electrodes 6 and 8 are attached to the outer peripheral surfaces of the accelerating tube 3 and the exhaust tube 7 at equal angular intervals, and the resistors 4 and 9 are connected between them. Although the potential up to the ground earth is forcibly divided at equal intervals, the electrode 6 of the acceleration tube 3 and the electrode 8 of the exhaust tube 7 are opposed to each other. Although the electrodes should be on the equipotential surface, the electrodes facing each other are not necessarily on the equipotential surface depending on the value of the current flowing through each resistor or the insulation between them. , Electrodes and metal hoops 5
There is a risk of damaging the device.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and provides an ion implantation apparatus in which no discharge occurs between, for example, the acceleration pipe 3 and the exhaust pipe 7 arranged in parallel with the acceleration pipe. The purpose is to do.

[0010]

SUMMARY OF THE INVENTION The object of the present invention is to provide a casing having at least a built-in ion source and a mass separation magnet at a predetermined height from the ground, and a high-voltage power supply unit for mounting the casing at a predetermined height. A voltage is applied, a power supply device supplies power to the ion source, the mass separation magnet, and the like, an exhaust device for exhausting the ion source is provided, and a shield box that electromagnetically shields the casing is provided. And providing the exhaust pipe of the exhaust device and the predetermined high voltage of the high-voltage power supply device to the casing between one side surface of the casing and an inner wall surface of the shield box facing the one side surface. A first bushing made of an insulating material, and a conductive member for leading out the power of the power supply device;
In an ion accelerator in which at least one cylindrical member of the second bushing made of an insulating material is connected to an accelerating tube and electrodes are fixed at equal pitches to their outer peripheral portions, respectively, This is achieved by an ion implantation apparatus characterized in that a resistance is connected only between one of the electrodes of the tube and the other of the electrodes is connected to each other by a metal rod.

[0011]

The accelerating pipe and the exhaust pipe, for example, are connected between the casing to which a high voltage is applied and the inner wall of the shield box for electromagnetically shielding the casing. Electrodes are attached to the outer periphery at equal pitches, for example, a resistor is connected only between the electrodes attached to the acceleration tube. Since metal rods are connected between these electrodes and the electrodes attached to the peripheral wall of the exhaust pipe and opposed to the respective electrodes of the acceleration pipe, they are electrically connected to each other. Although no resistance is connected to the electrodes, the electrodes of the accelerating tube and the electrodes of the exhaust tube are forcibly maintained at the same potential. Therefore, an equipotential surface is formed between the opposing electrodes, and no discharge occurs between the casing to which a high voltage is applied and the shield box. Furthermore, a resistor is connected between the electrodes of the acceleration tube, but no resistance is connected between the electrodes attached to the outer circumference of the exhaust pipe. Only the resistance connected between the electrodes mounted on the wall. Therefore, the resistance value becomes higher than before, the current flowing from the casing to the shield box becomes smaller, and the current load also becomes smaller. Therefore, since the resistance value can be made smaller and a cheaper resistor can be used than before, and the number of such resistors can be reduced, the device cost can be greatly reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ion implantation apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a main part of the implantation apparatus of the present embodiment. Parts corresponding to those of the conventional ion implantation apparatus are denoted by the same reference numerals, and detailed description thereof will be omitted. In FIG. 1, the metal hoop 5 attached to the outer peripheral portion of the acceleration pipe 3 and the electrode 8 fixed to the outer peripheral surface of the exhaust pipe 7 are connected by a connecting rod 20 made of metal according to the present invention. I have.

FIG. 2 shows the detail of B shown by a dashed line in FIG. 1. A threaded hole is formed at one end of the connecting rod 20, and a cylindrical member is screwed into the threaded hole. A bowl and a bowl plunger 22 having a metal bowl fixed to the upper end thereof are disposed therein. The bowl has a hole 5 a formed in a part of the metal hoop 5 fixed to the acceleration tube 3. Is fitted. This engagement is ensured by a spring force built in the bowl plunger 22.

The other end of the connecting rod 20 has a slot-like groove 2.
0a is formed, and a part of the electrode 8 fixed to the outer periphery of the exhaust pipe 7 is inserted into this. A small screw hole 20b is formed orthogonal to the slot-like groove 20a, and a hexagon socket set screw 23 is screwed into the small screw hole 20b to fix the electrode 8 fixed to the exhaust pipe 7.
That is, the connecting rod 20 is attached to the acceleration pipe 3 and the exhaust pipe 7 at both ends. The length L from one end to the other end of the connecting rod 20 is adjusted within the range of the axial length of the groove 20a so as to be adapted to the distance between the exhaust pipe 7 and the acceleration pipe 3. I have.

The injection device according to the embodiment of the present invention is configured as described above. Next, this operation will be described. The operation of the ion implantation is the same as that of the conventional one, except that the accelerating tube 3 and the exhaust tube 7 are connected by a connecting rod 20 made of metal, and each electrode 6 fixed to the outer peripheral surface of the accelerating tube 3 Since it is opposed to the electrode 8 fixed to the outer peripheral surface of the exhaust pipe 7,
The metal hoops 5 of the accelerating tube 3 and the electrodes 8 fixed on the outer peripheral portion of the exhaust pipe 7 facing the metal hoops are reliably placed on the equipotential surface, and no discharge occurs between them.

According to the present embodiment, no resistance is connected between the electrodes 8 fixed to the outer peripheral surface of the exhaust pipe 7, but this is because a metal hoop fixed to the outer peripheral surface of the acceleration pipe 3 is used. This is because the resistor 4 'connected between the terminals 5 can be commonly used. Therefore, not only the cost is reduced by reducing the number of expensive resistance elements, but also conventionally, a resistance is connected between the electrodes of the acceleration pipe 3 and the exhaust pipe 7, respectively.
In addition, high voltage and high withstand voltage resistors are used, and high resistance values are used to reliably prevent dielectric breakdown. These are connected in parallel between the high voltage terminal 2 and the shielding casing 1 so to speak. Therefore, the current becomes smaller than the sum of the resistances 4 connected between the metal hoops 5 fixed to the outer periphery of the acceleration tube 3, so that the current becomes smaller and a higher resistance is required than in this embodiment. According to the present embodiment, since they are not connected in parallel, the sum of the resistance values is
In addition to reducing the number of resistance elements, it is possible to use less expensive resistance elements by using one having a smaller resistance value.

FIG. 3 shows a main part of an ion implantation apparatus according to a second embodiment of the present invention.
In addition, a bushing 12 connected to the insulating transformer 11 and a bushing 25 of the high-voltage power supply 16 are also mounted in parallel on the same side of the high-voltage terminal 2 as shown. And metal hoops 5, 25a fixed to these outer peripheral surfaces and arranged at equal intervals,
Between 19, a connecting rod 20 made of the same metal as in the first embodiment
A, 20B, 20C, and 20D are connected as shown in FIG. Thus, it is clear that the same effects as in the first embodiment can be obtained.

Although the embodiments of the present invention have been described above, the present invention is, of course, not limited to these, and various modifications can be made based on the technical concept of the present invention.

For example, in the above-described embodiment, the high-voltage power supply 16 is disposed below the high-voltage terminal 2. However, the insulating transformer 11 having the insulating bushing 12 is also disposed below the high-voltage terminal 2. The metal hoops or electrodes fixed to the outer peripheral surface may be connected to each other by a connecting rod 20 made of metal in the same manner as in the above embodiment. In this case, the high voltage terminal 2 and the bottom wall surface of the shielding box 1 can be reliably separated from each other by the equipotential surface, and discharge during this period can be prevented.

[0020]

As described above, according to the ion implantation apparatus of the present invention, discharge can be prevented.

[Brief description of the drawings]

FIG. 1 is a partially broken plan view of a main part of an ion implantation apparatus according to a first embodiment of the present invention.

FIG. 2 is an enlarged plan view of a main part B in FIG.

FIG. 3 is a partially broken plan view of a main part of an ion implantation apparatus according to a second embodiment of the present invention.

FIG. 4 is a side view taken along the line [4]-[4] in FIG.

FIG. 5 is a partially broken plan view of a conventional ion implantation apparatus.

[Explanation of symbols]

 20 connecting rod 20A connecting rod 20B connecting rod 20C connecting rod 20D connecting rod

Claims (1)

(57) [Claims] 1. A casing in which at least an ion source and a mass separation magnet are built in is disposed at a predetermined height from the ground, a predetermined high voltage is applied to the casing by a high voltage power supply, and To supply power to an ion source or a mass separation magnet, etc., an exhaust device for exhausting the ion source is provided, and a shield box for electromagnetically shielding the casing is provided, and one side surface of the casing, An exhaust pipe of the exhaust device and a conductive member for applying the predetermined high voltage of the high-voltage power supply device to the casing are provided between one side surface and an inner wall surface of the shield box facing the insulating box. The first made of wood
A bushing and a conductive member for leading out power of the power supply device are covered, and at least one cylindrical member of the second bushing made of an insulating material is connected to the accelerating tube. In an ion accelerator in which electrodes are fixed at a pitch, a resistor is connected only between one of the electrodes of the cylindrical member and the accelerating tube, and these electrodes and the other opposing electrode are each connected by a metal rod. An ion implanter characterized by being connected.