JPH0722851Y2 - Ion processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an ion processing apparatus for irradiating an ion beam onto a wafer mounted on a disk that is rotated at least in a vacuum container to process the wafer, The present invention relates to improvement of means for deriving an ion beam current from a rotary shaft for a disk.

[Conventional technology]

The ion treatment device includes, for example, an ion implantation device, an ion deposition thin film forming device that uses both ion implantation and vacuum deposition,
There is an ion beam etching device and the like. In the following, an ion implanter will be described as an example.

FIG. 2 is a schematic sectional view partially showing an example of a disk around a conventional ion implantation apparatus, and FIG. 3 is a schematic plan view showing the disk of FIG. This ion implanter
For example, as disclosed in Japanese Patent Laid-Open No. 58-198843, a so-called mechanical scan system is used in which the disk 6 is rotated and translated instead of being scanned by the ion beam 2.

That is, a disk 6 in which a plurality of wafers 4 are mounted on the same radius of the surface is housed in a vacuum container (not shown), and the disk 6 is moved by the disk rotation / translation mechanism 10 to, for example, an arrow B. For example, while being rotated at a high speed, the wafer 4 is translated perpendicularly to the ion beam 2 as indicated by an arrow C (in the front and back direction of the paper in FIG. 2), whereby the ions are uniformly implanted in each wafer 4. I am trying.

The disc rotating / translating mechanism 10 includes a moving body 12 supported by guide rails 14a and 14b so as to be linearly movable. The rotating shaft 8 coupled to the disc 6 has a ball bearing 24,
It is rotatably supported by the moving body 12 via 25.
Gears 20 and 22 which are attached to the drive shaft 18 and the rotary shaft 8 and mesh with each other are provided in the moving body 12, and the drive shaft 18 is rotated by a motor (not shown) so that the disk 6 described above is rotated. The rotation is performed as if it was done. A ball screw 16 is meshed with the moving body 12, and the ball screw 16 is rotated by a motor (not shown) so that the moving body 12 is linearly moved, that is, the disk 6 is translated as described above.

In this example, the disk 6 is configured to be cooled by a refrigerant W such as freon or cooling water, and a rotary joint 28 for supplying / recovering the refrigerant W is attached to the moving body 12. That is, the rotary joint 28 has a cylindrical stator 30, and the rotary shaft 8
Are extended into the stator 30 and are rotatably supported by ball bearings 26. A forward path 42 and a return path 44 for the refrigerant W are provided from the inside of the rotary shaft 8 to the inside of the disk 6, and a forward tube 36 and a return tube 38 of the refrigerant W connected to the stator 30 communicate with them. Incidentally, 34 is a packing for sealing movable parts and the like, and 32 is a lid.

In the apparatus as described above, the beam current I of the ion beam 2 with which the disk 6 and the wafer 4 on the disk 6 are irradiated is measured for various controls. For example, the translational speed v of the disk 6 is controlled so as to be v∝I / R based on the beam current I in order to uniformly ion-implant each wafer 4. R is the distance between the center of the disk 6 and the center of the ion beam 2 (see FIG. 3). Further, the dose amount of the ions implanted into the wafer 4 is also controlled based on the ion beam I.

Specifically, the ion beam I is led to a non-rotating portion, for example, the moving body 12 or the stator 30 of the rotary joint 28 via the rotary shaft 8 and the ball bearings 24 to 26, and further from there, for example, the lid 32. Lead wire connected to
It is guided to the current measuring device 48 via 46, etc., and is measured there.

[Problems to be solved by the invention]

However, a small amount of lubricating oil is applied to the ball bearings 24 to 26, which may serve as an insulating coating and cause the disk 6 to float electrically. In such a case, the disk 6 is charged (charged) to a high voltage with the irradiation of the ion beam 2, and when it exceeds a certain limit, the insulating coating is destroyed and instantly discharged. It will be repeated. As a result, the waveform of the beam current I measured by the current measuring device 48 is significantly disturbed, and various controls based on the beam current I may be disabled.

Therefore, the main object of the present invention is to provide an ion processing apparatus capable of solving the above problems.

[Means for solving problems]

The ion processing apparatus of the present invention is an apparatus for irradiating a wafer mounted on a disk that can be rotated at least in a vacuum container with an ion beam to process the wafer. A conductive ball case is housed and fixed in the center of the end of the, and a conductive coil spring is housed in this ball case, and a conductive ball is housed in the ball case, which is then fixed by the coil spring. The elastic member is elastically pressed against the non-rotating portion facing the end portion of the rotating shaft, thereby electrically conducting the rotating shaft and the non-rotating portion.

[Action]

The beam current flowing through the rotating shaft of the disk is led to the non-rotating portion via the conductive ball case, coil spring and ball. Therefore, unlike the conventional case, the insulating film is not affected by the lubricating oil in the bearing portion.
Moreover, the ball is in point contact with the non-rotating part facing the end of the rotating shaft, and since it is not necessary to apply a large force to the ball, friction and wear at the contact point are very small, and therefore, there is no mechanical obstacle. Nor.

〔Example〕

FIG. 1 is an enlarged sectional view partially showing an end portion of a rotary shaft for a disk of an ion implantation device according to an embodiment of the present invention. The same or equivalent parts as those in FIGS. 2 and 3 are designated by the same reference numerals, and the description thereof will be omitted.

In this embodiment, a ball case 50 is inserted and fixed in a hole 8b at the center of an end 8a of the rotary shaft 8 on the side opposite to the disk 6, and a coil spring (more specifically, a compression coil spring) is inserted therein. ) 52 and a ball 54 are mounted so that the ball 54 is elastically pressed against the opposed non-rotating portion, for example, the lid 32.

In this case, the ball case 50, the coil spring 52 and the ball
Since 54 is for electrically conducting the rotary shaft 8 and the lid 32, both are electrically conductive, for example, made of metal. In addition, the hole 8b is provided, for example, in the above-described refrigerant W on the rotating shaft 8.
It is easy to use the holes that are normally formed when the forward path 42 is provided. If there is no such hole, a new hole may be provided in the end portion 8b.

According to the above configuration, since the rotating shaft 8, the ball case 50, the coil spring 52, the ball 54 and the lid 32 are in conductive contact with each other, the beam current I flowing through the rotating shaft 8 is the ball case 50 and the coil spring 52. And, it is stably led out to the lid 32 which is a non-rotating portion via the ball 54. In other words, since the beam current I flowing through the rotating shaft 8 is not led to the non-rotating portion via the ball bearings 24 to 26 as in the conventional case, it is not affected by the insulating film of the lubricating oil in the ball bearings 24 to 26. Disappear. As a result, the beam current I can be measured and various controls based on it can be stably performed without any trouble.

Incidentally, there are various means for guiding the beam current I led to the lid 32 to, for example, the above-described current measuring device 48 or the like, for example, the lid 32 and the current measuring device 48 are connected by the lead wire 46 as illustrated. Connecting. Lead to the current measuring device 48 via the stator 30, the forward pipe 36, the return pipe 38, or the like, or the stator 3
It is possible to employ means such as guiding to the current measuring device 48 via the moving body 12, the guide rails 14a, 14b, etc. shown in FIG.

In the above case, although the ball 54 rotates with the rotating shaft 8, it does not need to exert a large force on the ball 54 because it contacts the lid 32 at one point of the center of rotation of the rotating shaft 8 and is only for conduction. The friction and wear at the contact points between the balls 54 and the lid 32 are very small, and therefore there is no mechanical problem.

In the above description, the ion implantation apparatus that rotates and translates the disk has been described as an example, but the present invention is not limited thereto. For example, an ion implantation apparatus that linearly scans an ion beam to rotate the disk, Further, the present invention can be applied to the ion treatment apparatus other than the ion implantation apparatus as exemplified at the very beginning.

[Effect of device]

As described above, according to the present invention, the beam current flowing in the rotating shaft of the disk can be stably led to the non-rotating portion via the conductive ball case, the coil spring, and the ball. As a result, measurement of the beam current,
Further, various controls based on it can be stably performed without any trouble.

Moreover, since the ball case, the coil spring, and the ball are all housed inside the end of the rotary shaft, even if these parts are provided, no special space is required around the end of the rotary shaft. Therefore, there is an effect that it is possible to prevent the size around the rear portion of the rotary shaft from increasing.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view partially showing an end portion of a rotary shaft for a disk of an ion implantation device according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view partially showing an example around a disk of a conventional ion implantation apparatus. Figure 3 shows the second
It is a schematic plan view which shows the disk of a figure. 2 ... Ion beam, 4 ... Wafer, 6 ... Disk,
8 …… Rotary shaft, 24-26 …… Ball bearing, 28 …… Rotary joint, 32 …… Lid, 50 …… Ball case, 52
…… Coil spring, 54 …… Ball, I …… Beam current.

Claims (1)

[Scope of utility model registration request] 1. An apparatus for irradiating a wafer mounted on a disk, which is rotated at least in a vacuum container, with an ion beam to process the wafer, the end of a rotating shaft connected to the disk opposite to the disk. A conductive ball case is housed and fixed in the center of the, a conductive coil spring is housed in the ball case, and a conductive ball is housed in the ball case, which is then
Elastically pressed against the non-rotating part facing the end of the rotating shaft,
The ion treatment device is characterized in that the rotation shaft and the non-rotating portion are thereby electrically conductive.