JPS60193250A - Ion implantation device - Google Patents

Abstract

PURPOSE:To minimize the damage to an ion implantation device caused by the breakage of the wafer by forming piercing holes in given positions of a wafer holder and a disk and by transmitting light from a light-emitting circuit to a light-receiving circuit through the piercing holes when the wafer is broken and scattered. CONSTITUTION:A disk 20 and a wafer holder 21 have piercing holes 26. A chamber 25 and its lid 27 have openings 28 which are continuous with the piercing holes 26. When a wafer 41 is broken and scattered due to a great centrifugal force applied during high speed rotation, a given optical signal is sent from a light-emitting circuit 29 to a light-receiving circuit 30 through the piercing holes 26 and the openings 28. As the result, a given interruption signal is delivered from the light-receiving circuit 30 to an interruption circuit 32 thereby interrupting the rotation of the disk 20 and the supply of an ion beam current. Accordingly it is possible to minimize the damage to an ion implantation device caused by the scattering of the wafer 41.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to an ion implantation device.

[Technical background of the invention]

Conventionally, ion implantation equipment has been used to form impurity regions such as sources and drains constituting semiconductor devices. An ion implanter is assembled from an extremely large number of parts, including both the vacuum system and the electrical system. FIG. 1 is an explanatory diagram showing the main parts of a conventional ion implanter. In the figure, reference numeral 1 denotes a disc-shaped disk that holds a large number of wafers 2. As shown in FIG. The disk l is connected to a drive unit 3 provided at the rear thereof,
It rotates at a predetermined speed. On the surface of the Weno S2 held by the Disc 1, there is a soluping ano! installed in front of the Disc J. - Char 4. Suppression electrode 5. A predetermined ion beam 7 that has sequentially passed through the Faraday flag 6 is irradiated. FIG. 2 is a sectional view showing how the wafer 2 is mounted in this ion injection λ pot #10. In the figure, reference numeral 11 denotes a process chamber surrounding the disk 1 holding the wafer 2. A seal plate 12 is attached to the front surface of the process chamber 11. The seal plate 12 is connected to a vacuum pump (not shown). Note that 13 is a wafer holder formed on the disk 1.

[Problems with background technology]

According to the ion implantation apparatus 10 configured in this manner, the wafer 2 fixed to the disk 1 is scraped and broken into small pieces during vacuum evacuation when the chamber is closed and the disk 1 is rotating at high speed, or during ion implantation. Accidents may occur where the particles become scattered.

Serious damage to the scattered small pieces, the spindle of the disk 1, the dirt valve, the leak valve, the beam line, the vacuum system such as the cryopump, the electric system such as the bias of the Faraday cage, and other disks 1 and wafer holder 13. give. Naturally, the wafer 2 that was not cracked also becomes unusable. The occurrence of such cracks in the wafer 2 is caused by small "flaws" around the wafer 2 during the manufacturing process of semiconductor devices.
and "kake" are formed, and such "scratches" and "kake"
Since most of the scratches cannot be detected with the naked eye, it is thought that the wafer 2 is set in the wafer holder 13 with scratches and the like and is subjected to large centrifugal force due to high speed rotation.

Conventional ion implantation equipment does not have a mechanism to detect if the wafer 2 breaks and scatters, so if the wafer 2 is seriously damaged, the equipment must be stopped immediately, or if the wafer 2 is left with significant damage. Currently, the ion implantation operation is performed, and it is not known until after the ion implantation operation is completed and the chamber is opened that an accident has occurred. For this reason, there is a problem in that damage caused by cracking of the wafer 2 is large and that the operating rate is lowered.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ion implantation apparatus that minimizes damage caused by wafer cracking accidents and improves operating efficiency.

[Summary of the invention]

In the present invention, through-holes are formed at predetermined positions of the wafer holder and the disk, and when the wafer 1 is scattered, light is inserted through the through-hole and propagated from the light emitting circuit to the light receiving circuit, thereby preventing the wafer from cracking. By making it possible to detect wafers immediately, damage caused by wafer cracking accidents can be minimized.
This is an ion implanter that has achieved improved operating rates.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is an explanatory diagram showing a main part of an embodiment of the present invention. In the figure, 20 is a disk-like ′σ disk, and the disk 2
A large number of wafer holders 21 are attached at predetermined intervals along the circumferential direction on the peripheral edge of the surface of the wafer 0 . A rotating shaft 22 is attached to the center of the back surface of the disk 20.

The rotating shaft 22 is connected to a motor 24 of a drive section 23. The disk 20 is housed within a chamber 25. A through hole 26 is opened in the disk 20 and the wafer holder 21 to pass through them. chamber 2
5 and its lid 27 are formed with an opening 28 communicating with the through hole 26. A light emitting circuit 29 is attached to the open end of the opening 28 on the chamber 25 side. A light receiving circuit 30 is attached to the opening end of the opening 28 on the lid 27 side. Chamber 25 and lid part 2
An opening/closing sensor 31 is attached to the mating portion 7. The output signal of the light receiving circuit 30 is supplied to the motor 24 and the ion beam current stopping circuit 32. Stop circuit 32. The opening/closing sensor 3/1 light emitting circuit 29 is
electrically connected. Note that an ion beam supply section (not shown) is provided in front of the chamber 25 so as to face the wafer holder 21 through the opening of the chamber 25.
is provided.

According to the ion implantation apparatus 40 configured in this manner, the wafer 41 is placed in each wafer holder 21, and the chamber 25 and the lid part 27 are closed in order to perform ion implantation.

Next, a degree of vacuum is set to about 10<-5 >Torr on the outside of the chamber 25 by an exhaust mechanism (not shown). The disk 20 rotates at high speed during the subsequent vacuum evacuation operation and ion implantation operation. When the weno 141 is subjected to a large centrifugal force due to this high-speed rotation and breaks and scatters, the through hole 26 and the opening 28 communicate with each other, and a predetermined optical signal flows from the light emitting circuit 29 to the light receiving circuit 30.

As a result, a predetermined stop signal is output from the light receiving circuit 30 to the stop circuit 32. Therefore, upon receiving a signal from the stop circuit 32, the rotation of the disk 20 and the supply of ion beam current are stopped. Therefore, the vacuum seal part of the disc rotating part, the dart valve.

Vacuum systems such as Liebel, beam lines, cryopumps, electrical systems such as Faraday bias, and
The disk 20, wafer holder 21, etc. are attached to the wafer 4.
Damage caused by scattering of 1 can be minimized. As a result, the time required for disassembling and assembling the device after an accident can be shortened, and the operating rate of the device can be increased.

〔Effect of the invention〕

As explained above, according to the ion implantation apparatus according to the present invention, it is possible to minimize the damage caused by wafer cracking accidents and improve the operating rate.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the main parts of a conventional ion implantation device;
FIG. 2 is a cross-sectional view showing a state in which a wafer is attached to the ion implantation apparatus, and FIG. 3 is an explanatory view showing a main part of an embodiment of the present invention. 20... disk, 21... wafer holder, 22
...Rotating shaft, 23...Drive unit, 24...Motor,
25...Chamber, 26...Through hole, 27...
Lid part, 28... Opening part, 29... Light emitting circuit, 30.
...Light receiving circuit, 3...Opening/closing sensor, 32...Stop circuit, ±1...Ion implanter, 41...Weno 1゜Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2

Claims (1)

[Claims] A letter wafer holder installed at a predetermined interval on a peripheral edge of a plate-shaped disk, a through hole formed by inserting the wafer holder and the disk, a chamber accommodating the disk, and a through hole in the chamber. an opening formed so as to communicate with each other, a light emitting circuit provided at one end of the opening, and a light receiving circuit provided at the other end of the opening;
a stop circuit electrically connected to the light receiving circuit and the light emitting circuit; a rotating shaft that penetrates the chamber and has one end connected to the disk and the other end connected to the drive section; and an opening of the chamber. An ion implantation apparatus comprising: an ion beam supply section provided to face the wafer holder via the wafer holder.