JPH08180829A - Oxygen ion implanting device - Google Patents

Abstract

PURPOSE: To miniaturize and purify an oxygen ion implanting device for making a SIMOX base plate for forming an embedded oxygen film in a silicon wafer by ion beam implantation. CONSTITUTION: This oxygen ion implanting device has an ion source 10 for generating an ion beam; a connecting pipe 11 for connecting the ion source 10 to a mass separator; the mass separator 12 for taking out only a necessary ion component oxygen ion in this embodiment); an accelerating tube 13; a quadrupole lens 14; a deflection magnet 15; and an end station 16. The ion source 10 is provided with an ion beam extraction electrode 20 for three- dimensionally converging the ion beam near the incident point of the mass separator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxygen ion implanter used for forming a buried oxide film in a wafer by implanting oxygen ions into the wafer.

[0002]

2. Description of the Related Art A conventional oxygen implantation apparatus is an apparatus and method for ion implantation of a semiconductor wafer (Japanese Patent Application Laid-Open No. 6-58242).
1-116746), there is no particular description about the beam extracted from the ion source, and a parallel beam was used as in the ion implantation apparatus for impurity implantation.

[0003]

However, the SIM
In an oxygen ion implantation apparatus for manufacturing an OX (Separation Implanted Oxygen) substrate, a required beam current is one digit or more larger than that of a conventional ion implantation apparatus for impurity implantation.

If the beam extracted from the ion source in the ion implanter is a parallel beam, the size of the beam incident on the mass separator increases as the beam current value extracted from the ion source increases. Therefore, if the beam extracted from the ion source is used without being lost, the vacuum container of the mass separator becomes large, and the magnetic pole spacing of the mass separating magnet becomes large accordingly, and the magnet itself also becomes large. Moreover, each device after that also becomes large-sized.

When the parallel beam is used as in the conventional ion implanter, the respective devices constituting the ion implanter become large in size, and hence the ion implanter becomes large in size and high in cost. Therefore, there is a problem that the SIMOX substrate manufactured by this oxygen injection device is also expensive.

The present invention has been made in view of the above circumstances, and the size of the entire apparatus is reduced and the cost of the apparatus is reduced regardless of the beam current value drawn from the ion source, and the beam is injected. It is an object of the present invention to provide an oxygen ion implantation apparatus in which impurities and particles generated by collision with the inner wall of a vacuum container constituting the apparatus are reduced.

[0007]

The oxygen ion implantation apparatus of the present invention is an ion source for generating an ion beam and extracting the ion beam from a porous ion beam extraction electrode, and an oxygen ion beam from the ion beam emitted from the ion source. A mass separator for separating the oxygen ion beam, an accelerating tube for accelerating the oxygen ion beam emitted from the mass separator, a quadrupole lens for controlling the cross-sectional shape of the oxygen ion beam accelerated by the accelerating tube, and the quadrupole In an oxygen ion implanter having a deflection magnet for deflecting an oxygen ion beam emitted from a polar lens, and an end station on which a wafer is placed, on which the oxygen ion beam deflected by the deflection magnet is incident,
The mass separator constitutes a three-dimensional focusing system that focuses an ion beam at an entrance point and an exit point, the porous ion beam extraction electrode is composed of a plurality of electrodes, and the plurality of electrodes are part of a concentric sphere. It is characterized in that it is curved so as to form.

The oxygen ion implantation apparatus of the present invention comprises an ion source for generating an ion beam and extracting the ion beam from a porous ion beam extraction electrode, and a mass separator for separating the oxygen ion beam from the ion beam emitted from the ion source. An accelerating tube for accelerating the oxygen ion beam emitted from the mass separator, a quadrupole lens for controlling the cross-sectional shape of the oxygen ion beam accelerated by the accelerating tube, and oxygen emitted from the quadrupole lens In an oxygen ion implantation apparatus having a deflection magnet for deflecting an ion beam and an end station on which a wafer is installed, into which the oxygen ion beam deflected by the deflection magnet is incident, the mass separator includes an incident point and an emission point. And form a three-dimensional focusing system for focusing the ion beam, and the porous ion beam extraction electrode is composed of a plurality of flat plate electrodes. , Each plate electrode, characterized in that the ion beam extraction hole is formed so as to deflect each plate electrodes.

[0009]

In the oxygen ion implanter having the above-described structure, the mass separator is configured to stereofocus the ion beam, and the ion beam shape at the incident point of the mass separator is created at the exit-side stereofocusing point. Has become. Therefore, if the ion beam size at the mass separator incident point is made smaller, the ion beam size after the mass separator incident point can be made smaller, so that each component can be made smaller.

As described above, by making the beam extracted from the ion source into a beam that converges at one point in the vicinity of the mass separator, the size of the entire apparatus can be reduced.

Further, if the size of the ion beam is reduced, impurities and particles generated by the collision of the beam with the inner surface of the vacuum container can be reduced.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the overall configuration of an embodiment of the oxygen ion implantation apparatus according to the present invention. In the figure, the oxygen ion implanter includes only an ion source 10 for generating an ion beam, a connecting pipe 11 for connecting the ion source 10 and a mass separator, and a necessary ion component (oxygen ion in this embodiment). Mass separator 12 for taking out the gas, accelerating tube 13, and quadrupole lens 14
And a deflection magnet 15 and an end station 16.

Further, inside the ion source 10, there is provided an ion beam extraction electrode 20 for focusing the ion beam in the vicinity of the incident point of the mass separator. Ion beam extraction electrode 2
A specific configuration of 0 is shown in FIG. In the figure, the ion beam extraction electrode 20 is an acceleration electrode 20A and a deceleration electrode 20.
B, ground electrode 20C, and each electrode is provided with a plurality of ion beam extraction holes for passing an ion beam. In order to focus the ion beam in front of the ion source 10 by the ion beam extraction electrode 20 near the incident point of the mass separator 12, the acceleration electrode 20A, the deceleration electrode 20B, and the ground electrode 20C form a part of a concentric sphere. Curved to form. An ion source 10 (not shown) is located on the left side of the ion beam extraction electrode 20 in FIG.

Since the ion source 10 of the oxygen ion implanter having the structure shown in FIG. 1 has an extraction energy of about 50 kV, the ion beam extraction electrode 20 has a three-electrode structure.

Since the beam radius (r) of the mass separator 12 is selected to be 540 mm, the distance from the ion source 10 to the incident point of the mass separator 12 is 1080 mm here.
(2r).

Reference numeral 17 is a rotary stage for rotating the wafer 18, and reference numerals 30, 31, 32 are gate valves used for maintenance of the apparatus.

In the above structure, the ion beam extracted from the ion source 1 passes through the connecting pipe 11 and the mass separator 12.
The light is incident on the mass separator 12 so as to be three-dimensionally converged in the vicinity of the incident point of.

Since the deflection angle of the ion beam incident on the mass separator 12 differs depending on the mass number of the ions, the mass separator 12 except for the necessary ions (oxygen ions in this embodiment).
It is struck by a beam damper provided inside, and only the necessary oxygen ion beam is made incident on the accelerating tube 13 located at the latter stage of the mass separator 12 to be accelerated to the required energy and made incident on the quadrupole lens 14. It

The ion beam incident on the quadrupole lens 14 is bent by the deflection magnet 15 and the magnetic field of the quadrupole lens is adjusted so that the ion beam enters the wafer 18 installed in the end station 16 so as to have an optimum sectional shape. (The beam cross section is shaped from circular to rectangular here). The shaped beam is deflected by a deflection magnet, separated again from the neutral beam and other residual impurities, and then incident on the wafer 18 installed in the end station 16.

In the present embodiment, the mass separator 12 employs a three-dimensional focusing system, so that the image of the incident point appears at the outgoing point as it is. Therefore, the mass separator 1
If the cross-sectional size of the ion beam at the incident point in 2 is reduced, the cross section of the ion beam after the incident point can be reduced.

In the above embodiment, as one means for converging one point in the vicinity of the incident point of the mass separator 12 like the ion beam extraction electrode 20, among the three flat plate-shaped electrodes forming the ion beam extraction electrode, The position of the beam extraction hole of the deceleration electrode or the ground electrode may be deviated.

[0022]

According to the present invention, even if the beam current of the beam generated by the ion source is increased, the device after the mass separator can be downsized and the beam may come into contact with the inner wall of the vacuum container. Since the amount of impurities and particles brought into the wafer can be reduced because of the reduction, it is possible to realize a small-sized and low-cost device and a high-performance oxygen ion implantation device with few impurities and particles.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an overall configuration of an oxygen ion implantation apparatus according to the present invention.

FIG. 2 is an explanatory diagram showing an electrode structure of an ion beam extraction electrode in the ion source in FIG.

[Explanation of symbols]

 10 Ion Source 11 Connection Tube 12 Mass Separation Tube 13 Accelerator Tube 14 Quadrupole Lens 15 Deflection Magnet 16 End Station 17 Rotating Stage 18 Wafer 20 Ion Beam Extraction Electrode 30 Gate Valve 31 Gate Valve 32 Gate Valve

Claims (2)

[Claims] 1. An ion source for generating an ion beam and extracting the ion beam from a porous ion beam extraction electrode; a mass separator for separating an oxygen ion beam from the ion beam emitted from the ion source; and a mass separator. An accelerating tube for accelerating the emitted oxygen ion beam, a quadrupole lens for controlling the cross-sectional shape of the oxygen ion beam accelerated by the accelerating tube, and a deflection magnet for deflecting the oxygen ion beam emitted from the quadrupole lens And an oxygen ion implanter having an end station on which a wafer is installed, into which the oxygen ion beam deflected by the deflection magnet is incident, wherein the mass separator converges the ion beam at an incident point and an emission point. In the three-dimensional focusing system, the porous ion beam extraction electrode is composed of a plurality of electrodes, and the plurality of electrodes are one of concentric spheres. An oxygen ion implanter characterized by being curved so as to form a portion. 2. An ion source for generating an ion beam and extracting the ion beam from a porous ion beam extraction electrode, a mass separator for separating an oxygen ion beam from the ion beam emitted from the ion source, and a mass separator An accelerating tube for accelerating the emitted oxygen ion beam, a quadrupole lens for controlling the cross-sectional shape of the oxygen ion beam accelerated by the accelerating tube, and a deflection magnet for deflecting the oxygen ion beam emitted from the quadrupole lens And an oxygen ion implanter having an end station on which a wafer is installed, into which the oxygen ion beam deflected by the deflection magnet is incident, wherein the mass separator converges the ion beam at an incident point and an emission point. A three-dimensional focusing system is configured, and the porous ion beam extraction electrode is composed of a plurality of plate electrodes, and each plate electrode has an ion beam. An oxygen ion implanting device, characterized in that the hole for drawing out holes is formed so as to deviate for each plate electrode.