JPH02260360A - Ion implantation apparatus - Google Patents

Abstract

PURPOSE:To easily assemble and position a plurality of electrodes which are for parallel scanning by forming a plurality of frange installation ports in a same distance along the surroundings of a vacuum container of a multipole deflection scanning system in the circumference direction and fitting each electrode installation frange in each flange installation port. CONSTITUTION:The outer plane of a vacuum container 6 forms an octangon shape and flange installation ports 7 are formed in each of the lines of the octangon in the longitudinal direction. An electrode installation flange 3 is fixed in a vacuum sealing plane 8 of the periphery area of each flange installation port 7 through an O-ring 9, bolted with bolts 10 so as to each deflection electrode 1 is assembled in the inside of the vacuum container 6 and positioned in relative, precise position. When each electrode 1 is fixed in the prescribed position of the electrode installation flange 3, eight deflection electrodes 1 can be positioned in prescribed relative, precise positions automatically by installing each electrode installation flange 3 in each flange installation port 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a parallel scanning ion implantation apparatus used for semiconductor manufacturing, surface modification or surface analysis of materials, and the like.

[Prior Art] In the ion implantation process that requires extremely high integration such as VLSI, shadowing becomes a problem as the pattern width becomes narrower, and shadowing at the edge of the wafer becomes a problem as the diameter of the wafer becomes larger. The uniformity of ion implantation is poor,
It is known that the ion beam needs to be implanted into the wafer in parallel because channeling is likely to occur.

For example, the conventional electrostatic type X as shown in FIG.
- In a deflection scanning system in a Y-sweep type ion implanter, a parallel plate type deflection electrode A for X direction deflection and a parallel plate type deflection electrode B for X direction deflection are arranged in series in a vacuum chamber C, and each Ions are deflected using a parallel plate type deflection electrode A for deflection in the X direction.
After being deflected in the X direction by the parallel plate type deflection electrode B for deflection in the X direction, the ion beam is scanned onto the wafer D by the combined displacement, and ions are implanted. Since each ion is displaced in one composite direction, it is implanted into the wafer D as an ion beam with a spread angle of about 8 degrees.

In this method, the electrode part inside the wound is approximately 80 cm wide and approximately 50 cm long.
It is relatively short and has an hour wheel-like structure, and since it is a parallel plate type, by making the vacuum container C square, it can be made smaller with less wasted space. Since it is only deflected in one direction about
The ion beam will not be parallel.

Therefore, a system has been proposed in which the ion beam can be scanned in parallel by using two parallel plate type electrostatic deflectors for deflection in the X and Y directions, and examples thereof are shown in FIGS. 3 and 4.

FIG. 3 shows the first parallel plate deflector E and the second flat scanning method. In this method, the ion beam is deflected in the X direction and the X direction by the first parallel plate deflector E, and the deflection given by the first parallel plate deflector E is deflected by the second parallel plate deflector F. The ion beams are deflected in the X direction and the X direction so as to cancel the angles, and as a result, a parallel ion beam is formed.

FIG. 4 shows another conventional parallel scanning system, in which a first parallel plate quadrupole deflector G and a second parallel plate quadrupole deflector H are arranged in series. A parallel plate quadrupole deflector G deflects the ion beam in one X direction and an The deflection is made in the X direction and in the X direction so as to cancel out the given deflection angle.

[Problems to be Solved by the Invention] As shown in FIGS. 3 and 4, a parallel ion beam can be generated by increasing the number of deflection electrodes, but in either method, the electric field at the edge Due to the turbulence, the effective area is narrow and a large width must be taken, making the electrode large and causing considerable deflection distortion, and the length of the entire electrode section is extremely long (3 m in the case of Figure 3).
(2.7 m in the case of Figure 4) and the electrode width is also large (45 cIIl in both Figures 3 and 4), which increases the overall size of the device, increases the installation area of the device, and increases production costs. will be affected.

From this perspective, the applicant arranged two octupole deflectors I and J in series as shown in FIG. Ion implantation with a multipole deflection scanning system that deflects the ions in the X and X directions with the second octupole deflector J so as to cancel the deflection angle given by the proposed a device. As a result, compared to the parallel plate type shown in Figures 3 and 4, the effective uniform electric field area is wider and the length is shorter (1.6 m), making it possible to provide a highly practical device. became.

However, even with the previously proposed electrode, the width and length are approximately three times as large as those of the conventional electrode section shown in Figure 2, and the electrode section requires that each electrode be removed individually for maintenance. Must be disassembled, cleaned and reassembled. Therefore, in the conventional electrode assembly structure in which all electrodes are attached to one flange as shown in Figure 2, when the number of electrodes increases as shown in Figure 5, it is difficult to position the electrodes with high precision and sufficient strength. Figures 2 and 4
This is significantly more difficult than when the number of electrodes is two or four as shown in the figure, and is not practical.

Insufficient positional accuracy of the electrodes not only impairs the parallelism of the ion beam that could originally be obtained, but also reduces the effective space between the electrodes that helps to make the ion beam parallel, and as a result, the performance of the ion implanter is affected. This will reduce the

The present invention solves the above-mentioned problems, and aims to provide an ion implantation apparatus in which a plurality of electrodes for parallel scanning can be easily assembled and positioned.

[Means for Solving the Problems] In order to achieve the above object, an ion implantation apparatus according to the present invention has an ion implantation apparatus in which each electrode of a multipole deflection electrode forming a multipole deflection scanning system that scans an ion beam in parallel is connected to an independent electrode. For mounting, fix to the flange, and for mounting multiple flanges, provide ports at equal intervals along the circumference around the vacuum vessel of the multipole deflection scanning system, and for each flange mounting, attach a flange to the port, and for electrode mounting, install a flange. The device is characterized in that each deflection electrode is relatively positioned within the vacuum container.

[Function] In the ion implantation apparatus of the present invention, a plurality of flange mounting ports are provided at equal intervals along the circumferential direction around the vacuum vessel of the multipole deflection scanning system, and each flange mounting port is provided with an electrode mounting port. is equipped with a flange,
The vacuum vessel itself of the multipole deflection scanning system functions as a means for positioning the electrodes, and the flange of each electrode with each deflection electrode attached is always the same positioning accuracy by mounting the flange of the vacuum vessel so that it is in surface contact with the port. can be obtained with sufficient strength.

[Example] Hereinafter, an example of the present invention will be described with reference to FIG. 1 of the accompanying drawings.

FIG. 1 shows an embodiment of the present invention, in which each electrode 1 of an aluminum octupole deflection electrode forming one of the electrode parts of a parallel scanning system is attached to a flange by two insulator support rods 2. 3 are fixed parallel to each other, and each electrode is attached to the flange 3.
A current introduction terminal 4 is provided on the outer surface of the electrode 1, and this current introduction terminal 4 is connected to the electrode 1 via a lead wire 5. A deflection voltage is applied to each current introduction terminal 4 from a power source (not shown).

Further, in FIG. 1, reference numeral 6 denotes a cylindrical vacuum container housing eight deflection electrodes 1. The outer surface of this vacuum container 6 forms a hexagon, and ports 7 are provided with flanges on each side along the longitudinal direction. It is formed. Each flange is attached to the vacuum sealing surface 8 at the edge of the port 7 via an O-ring 9, and the electrode is attached by bringing the flange 3 into surface contact with the flange 3. By tightening the bolt 10, each deflection electrode 1 is installed in the vacuum vessel 6. integrated and relatively precisely positioned.

By fixing each electrode 1 at a predetermined position with respect to the flange 3, the eight deflection electrodes 1 are automatically set in place by simply attaching the flange 3 to port 7. can be positioned relative to each other.

When taking out the deflection electrode l installed in the vacuum container 6 in this way, the deflection electrode l can be easily taken out from the vacuum container 6 by loosening the bolt 10 for tightening and removing the flange 3 for attaching the electrode.

Incidentally, in the illustrated embodiment, each electrode attachment is provided with one deflection electrode 1 on the flange 3, but one electrode attachment may be made such that a plurality of electrodes are attached to the flange. For example, one electrode can be attached by attaching two electrodes to a flange and attaching them to each side of a vacuum vessel having a rectangular cross section.

Further, in the above embodiment, the number of electrodes is eight. [Effects of the Invention] As explained above, in the ion implantation apparatus of the present invention, the electrodes are arranged circumferentially around the vacuum chamber of the multipole deflection scanning system. For mounting multiple flanges at equal intervals, ports are provided, and for each flange mounting, a flange is attached to each port, so for electrode mounting with each deflection electrode attached, the flange can be attached to the flange of the vacuum vessel. By attaching it so that it makes surface contact with the port, it is possible to always obtain the same positional accuracy with sufficient strength. In addition, the electrostatic scanning electrode can be easily taken out from the vacuum chamber of the scanning system during maintenance and inspection, making it easier to disassemble, clean, reassemble, and position each electrode, resulting in the operation of the ion implanter. Downtime can be kept to a minimum, thereby increasing equipment availability and improving productivity.

[Brief explanation of drawings]

Fig. 1 is a schematic exploded perspective view showing one embodiment of the present invention;
The figure is a schematic perspective view showing a deflection system in a conventional ion implanter, Figure 3 is a schematic perspective view showing a conventional parallel plate type deflection system, and Figure 4 is a schematic perspective view showing a conventional parallel plate type quadrupole deflection system. FIG. 5 is a schematic perspective view showing the previously proposed octupole deflection system. Middle 1: Deflection electrode 2: Insulator support rod 3: Pole mounting is on flange 4: Current introduction conductor 5: Lead wire 6: Vacuum vessel 7: Flange is mounted on port 8: Vacuum seal surface 9: O-ring 10: Tightening is bolted

Claims (1)

[Claims] 1. In a parallel scanning ion implanter equipped with a multipole deflection scanning system that scans the ion beam in parallel, each electrode of the multipole deflection electrodes forming the multipole deflection scanning system is fixed to an independent electrode mounting flange, and the multipole A plurality of flange mounting ports are provided at equal intervals along the circumferential direction around the vacuum vessel of the deflection scanning system, and each deflection electrode is mounted relative to the inside of the vacuum vessel by attaching an electrode mounting flange to each flange mounting port. An ion implanter characterized by positioning.