JPS62272443A - Ion doping device - Google Patents

Abstract

PURPOSE:To enable a radiation plane and radiation amount to be changed, by controlling movement of magnetic charged particles so that the charged particles are radiated on a substrate board, with readiness and less contamination on the substrate. CONSTITUTION:A gas-introduction pipe 8 is linked with an insulating cylindrical tube 1 in an ion doping device, and electrodes 2 for high-frequency glow discharge are disposed outside the cylindrical tube 1. One side of these electrodes 2 is earthed, and the other side of them 2 is connected with a high-frequency oscillator 4, wh se high-frequency wave causes glow discharge inside the cylindrical tube 1 to supply ionic gases from the introduction tube 8. Charged particles are drawn out through a nozzle 9 from the plasma inside the cylindrical tube 1, and applied to a drawn-out electrode 10. The electrode 10 is insulated from earth by usiug an insulating flange 11, and the particles are accelerated by means of a d-c power source 12. The particles from the nozzle 9 are then radiated to a sample on a substrate board 15 in a substrate chamber 14, to enable the radiation plane and radiation amount to be changed by electromagnets 18 and 19 respectively connected with d-c power sources 20 and 21.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention Field of Industrial Application The present invention relates to an ion doping apparatus used for implanting impurities into semiconductor elements and the like in the semiconductor industry.

Conventional technology In ion doping equipment, methods for uniformly irradiating doping ions onto a sample provided on a substrate table include electrical scanning of the generated charged particle beam and mechanical scanning of the charged particle beam on the substrate table. etc., and a method of controlling the irradiation surface and the irradiation amount was to provide a movable diaphragm in the bias section.

Problems to be Solved by the Invention In conventional techniques, methods using charged particle beam scanning and substrate stage scanning have complicated mechanisms, making it difficult to remove and maintain the mechanisms, and when using an aperture. There is a problem in that impurities generated by sputtering with charged particles contaminate the sample.

Means for Solving the Problems The means used by the present invention to solve the above problems is to provide two sets of independent magnetic field generating sections outside the substrate chamber, and to set the central axis of the two sets of magnetic field generating sections. By providing a substrate thereon, the charged particles irradiated onto the substrate stage can be made uniform and the irradiation surface and irradiation amount of the charged particles can be controlled using a simple mechanism with less impurity contamination.

That is, the present invention relates to an ion source and a gas exhaust pipe that are composed of, for example, an insulating cylindrical pipe connected to a gas introduction pipe, a high frequency electrode provided on the outside of the insulating pipe, a matching box connected thereto, and a high frequency power source. A substrate chamber consisting of a connected high vacuum chamber and a substrate stand provided inside the high vacuum chamber while maintaining insulation from the high vacuum chamber, and an extraction electrode and an insulating flange provided between the ion source and the high vacuum chamber. In an ion doping device consisting of a bias section,
Annular or cylindrical magnetic field generating sources that generate two independent magnetic fields are arranged at a distance outside the substrate chamber so that their central axes coincide, and a substrate table is placed on the central axis of the magnetic field generating sources. By providing the substrate pedestal so that their centers coincide, the irradiation surface and irradiation amount of the charged particles generated in the ion source, passed through the bias section, and transported to the substrate pedestal onto the substrate pedestal are controlled. be.

Function The present invention utilizes the movement of charged particles so as to wrap around lines of magnetic force to control charged particles irradiated onto a sample substrate placed on a substrate stand.

A cusp magnetic field is created on the substrate table and its surroundings by reversing the direction of the magnetic field generated by an electromagnet provided outside the substrate chamber. The position of the center of this magnetic field can be arbitrarily determined by adjusting the amount of current flowing through each electromagnet. A mirror magnetic field is created by making the directions of the magnetic fields generated by the electromagnets the same, and similarly, the position of the center of the magnetic field can be arbitrarily set by adjusting the amount of current flowing through each electromagnet. The above action can be achieved by making one of the electromagnets a permanent magnet and controlling the current of the other electromagnet. It is also possible to use permanent magnets as both electromagnets and move the positions of the magnets.

EXAMPLES The present invention will be explained in more detail below based on the drawings.

FIG. 1 shows a cross-sectional view of a first embodiment of an ion doping apparatus according to the present invention. The insulating cylindrical tube 1 of the ion source is made of quartz, ceramics, etc., and the electrode 2 for high-frequency glow discharge is made of copper, which has good conductivity.

Use metal such as nickel. One end of the electrode 2 is connected to a high frequency oscillator 4 via a matching box 3, the other end is grounded, and high frequency power is supplied to the insulating cylindrical tube 1 to generate plasma within the tube. Material gas is supplied to the ion source from a gas pump 6 (pulp, etc.) via a gas introduction pipe 8 connected to the insulating cylindrical pipe 1 through a flow rate control device 7.

The extraction electrode 1o, which has a nozzle 9 for extracting charged particles from the plasma generated inside the insulating cylindrical tube 1, has a floating potential with respect to the ground due to an insulating flange 11 made of vinyl chloride, acrylic, ceramics, etc. , is connected to the high voltage DC power supply 12. This extracts and accelerates the charged particles. A high vacuum (pressure 10-'10-'
A substrate stand 15 is provided inside the substrate chamber 14 (5 Torr),
This substrate stand 16 is fixed inside the substrate chamber 14 by a substrate support rod 16 and an insulating flange 17 made of vinyl chloride, acrylic, ceramics, etc., and a sample substrate is placed on it. Passing through the nozzle 9 of the extraction electrode 1o,
The charged particle beam, which has obtained kinetic energy corresponding to the potential of the extraction electrode 1o with respect to the substrate pedestal 15, irradiates the substrate pedestal. To make the irradiation of charged particles uniform and to control the irradiation surface and the irradiation amount, electromagnets 18.
This is done by the magnetic field generated by 9. This magnetic field is controlled by DC power supplies 20, 21 connected to each.

FIG. 2 is a sectional view of the substrate chamber during operation of the first embodiment of the ion doping apparatus according to the present invention. Electromagnet 1
A cusp magnetic field 22 is created inside the substrate chamber 14 by reversing the direction of the magnetic field created by each of the elements 8.19. By controlling the current flowing through the electromagnet so that the center of this cusp magnetic field is on the substrate table 15, the charged particle beam 23 spreads toward the substrate table, and the entire surface of the substrate table is irradiated with charged particles almost uniformly. The situation is shown in Figure 2 (,). Also, Figure 2 (
b) is a state in which no bias is applied to the extraction electrode, and the center of the cusp magnetic field 22 is shifted toward the electromagnet in order to suppress impurity ions and electrons from irradiating the substrate stage at the start of discharge, etc. This prevents contamination of the substrate stage due to unnecessary charged particle irradiation.

FIG. 3 is a partial cross-sectional view of a second embodiment of the ion doping device according to the present invention. The electromagnets 18 and 19 are each connected to a DC power supply 26 via a variable resistor 24 and 26, so that the current of each electromagnet 18 and 19 can be independently controlled by one DC power supply 26. This is possible, and the same effect as the first embodiment can be obtained.

FIG. 4 is a partial cross-sectional view of a third embodiment of the ion doping device according to the present invention. By providing a permanent magnet 27 made of ferrite or the like and an electromagnet 29 connected to a DC power supply 28 outside the substrate chamber and controlling the current of the electromagnet 29, the same effect as in the first embodiment can be obtained.

FIG. 5 is a partial cross-sectional view of a fourth embodiment of the ion doping apparatus according to the present invention. The same effect as in the first embodiment can be obtained by disposing the permanent magnets 30.31 movably outside the substrate chamber and changing the positions of the permanent magnets 30.31.

Effects of the Invention The present invention controls the movement of magnetically charged particles in an ion doping apparatus, and thereby irradiates the substrate stage with charged particles easily and with less contamination of the substrate. It becomes possible to uniformly irradiate the entire surface of the substrate stage with charged particles and to change the irradiation surface and irradiation amount of charged particles.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a first embodiment of an ion doping device according to the present invention, and FIGS. 2(a) and (b) are partial sectional views of the first embodiment of an ion doping device according to the present invention. , 3rd
The figure is a partial sectional view of the second embodiment, FIG. 4 is a partial sectional view of the third embodiment, and FIG. 5 is a partial sectional view of the fourth embodiment. 1...Insulating cylindrical tube, 2...High frequency electrode, 3-...Matching box, 4...
・High frequency power supply, 5... Gas cylinder, 6...
...Pulp, 7...Flow rate control device, 8...
Gas introduction pipe, 9...nozzle, 10...extraction electrode, 11...-insulation 7 lange, 12...
Vacuum pump, 13... Gas exhaust pipe, 14...
... Board chamber, 16... Board stand, 16... Board support rod, 17... Insulating flange, 18...
- Electromagnet, 19...Electromagnet, 2o...DC power supply, 21...DC power supply, 22...Magnetic field line, 23...Charged particle beam, 24・・・・・
・Variable resistor, 25... Variable resistor, 26... Old DC power supply, 27... Permanent magnet, 28... DC power supply, 29... Electromagnet, 3o... ...Permanent magnet, 31...Permanent magnet. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4

Claims (5)

[Claims] (1) An insulating cylindrical tube connected to the gas introduction tube, an ion source provided outside the tube, a high vacuum chamber connected to the gas exhaust tube, and an insulated tube inside the tube that is insulated from the high vacuum chamber. In an ion doping apparatus comprising a substrate chamber consisting of a substrate stand and a bias section provided between the ion source and the high vacuum chamber, an annular or cylindrical structure that generates two independent magnetic fields is used. By arranging magnetic field generation sources at intervals outside the substrate chamber so that their central axes coincide, and by providing a substrate stand so that the center of the substrate table coincides with the central axis of the magnetic field generation source. An ion doping apparatus characterized in that the irradiation surface and irradiation amount of charged particles generated in the ion source, passed through the bias section, and transported to the substrate pedestal onto the substrate pedestal are controlled. (2) The ion doping apparatus according to claim 1, wherein the magnetic field generating section is composed of two sets of electromagnets, and each electromagnet is connected to an independent DC power source. (3) Claim 1, characterized in that the magnetic field generating section is composed of two sets of electromagnets, and each electromagnet is connected to one DC power source via a variable resistor or a fixed resistor. ion doping equipment. (4) The ion doping apparatus according to claim 1, wherein the magnetic field generating section is comprised of one set of electromagnets and one set of permanent magnets. (5) The ion doping apparatus according to claim 1, wherein the magnetic field generating section is composed of two sets of permanent magnets.