JPH0728690Y2 - Ion processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is an apparatus such as an ion implantation apparatus in which ion beams can be irradiated even on the side wall of a recess provided on the surface of a wafer. The present invention relates to a processing apparatus, and more particularly, to improvement of a means for deriving an ion beam current flowing in a holder for holding a wafer.

[Background technology]

In recent years, along with the miniaturization of semiconductor devices, not only the bottom surface of a recess such as a hole or a groove carved on the surface of a wafer but also the side wall (side surface) thereof can be irradiated with an ion beam to perform ion implantation or the like. The demand for a device is increasing, and a device capable of meeting the demand has been separately proposed by the same applicant.

This will be described with reference to FIG. 3. An ion beam 4 from an ion source (not shown) or the like is introduced in the front side direction from the back side of the paper, for example, into a vacuum container 6 that is evacuated by a vacuum exhaust device (not shown). .

A hollow holder main shaft 20 is rotatably passed through the side wall of the vacuum container 6 via a rotary feedthrough 18 for vacuum sealing. The center line 20a of the holder spindle 20 is
Center point of the surface of the wafer 2 held by a holder 8 described later
It is designed to pass through 2a.

A hollow holder supporting arm 22 bent in a crank shape is attached to the inside of the vacuum container 6 of the holder main shaft 20, and gears that mesh with each other are provided on the outside of the vacuum container 6.
A reversible holder tilt motor 12 (holder tilt drive source) is connected via 16 and 14, and a holder rotation motor
32 (holder rotation drive source) is supported. Both motors 1
2 and 32 are, for example, stepping motors. 24 to 26 are lids of the holder supporting arm 22.

By rotating the holder tilt motor 12 as indicated by arrow J, the holder main shaft 20 can be rotated as indicated by arrow K together with the holder rotation motor 32, etc., and thereby the holder attached to the tip of the holder support arm 22. 8 and the wafer 2 can be fixed by rotating (tilting) between the horizontal state (implantation angle 90 degrees) and the vertical state (implantation angle 0 degrees) as shown.

A rotary shaft bearing 35, one end of which is connected to a holder rotation motor 32, is rotatably passed through the holder main shaft 20, and a holder is provided with a rotary feedthrough 39 for vacuum sealing at the tip of the holder support arm 22. A rotary shaft 38 is rotatably supported (axially supported). The rotary motion of the rotary shaft 35, for example, as indicated by the arrow F, is transmitted by a rotary transmission mechanism, that is, the rotary rotary shafts 36 and 37 rotatably supported in the holder support arm 22 by bearings 46 to 49, and three sets of bevel gears. 40-45
Is transmitted to the holder rotation shaft 38 via the, and the holder 8 attached to the holder rotation shaft 38 is rotated as indicated by an arrow G, for example.

A holder base 8a that constitutes the holder 8 that holds the wafer 2 is attached to the tip of the holder rotation shaft 38.
A ring-shaped clamper 8b, which also constitutes the holder 8 and presses the peripheral portion of the wafer 2, is provided on the upper portion thereof. This clamper 8b is moved up and down by a mechanism (not shown).

The wafer 8 is attached to and detached from (removed from) the holder 8 by carrying means (not shown) such as a carrying belt.

According to the above configuration, the wafer 2 held by the holder 8 can be processed in various modes, for example, in the following four modes, for example, by ion implantation, and the surface of the wafer 2 can be processed in any mode. Ions can be implanted not only on the bottom surface of the provided hole or groove, but also on the side wall.

Rotation Implant Mode The holder support arm 22 is rotated by the holder tilt motor 12 to bring the holder upright and the implantation angle of the ion beam 4 into the wafer 2 is set to a desired angle. In that case, since the center line 20a of the holder spindle 20 passes through the center point 2a on the surface of the wafer 2 on the holder 8 as described above, the center of the ion beam 4 coincides with the center of the wafer 2. In this case, the centers of the two do not shift even if the implantation angle is changed variously. Then, while the holder 8 and the wafer 2 are rotated (rotated) by the holder rotation motor 32, the wafer 2 is irradiated with the ion beam 4 to perform processing such as ion implantation.

Oscillation injection mode The holder tilt motor 12 causes the holder 8 and the wafer 2 to move.
Are ion-implanted while reciprocating between predetermined implantation angles. In that case, the holder 8 and the wafer 2 are not rotated.

Rotational rocking injection mode In this case, the above modes and are simultaneously performed.

Step rotation implantation mode This is a modification of the above mode, in which the holder 8 and the wafer 2 are intermittently rotated by a predetermined angle, and ions are implanted into the wafer 2 while the rotation is stopped. However, in this case, the wafer 2 whose orientation flat is aligned in the predetermined direction in advance is supplied to the holder 8, and the angle of intermittent rotation of the wafer 2 is set to a certain value with respect to the orientation flat.

[Purpose of device]

In the above-mentioned apparatus, the holder 8 is usually used for controlling the dose amount of ions implanted in the wafer 2, for example.
And the beam current of the ion beam 4 with which the wafer 2 on it is irradiated is measured.

Specifically, in this example, the holder support arm 22 and the mechanism therein are floated from the ground potential by the insulators 50 to 52, and one end of the holder rotation shaft 38 and the holder support arm 22 are also provided.
A contact 54 composed of a spring 56, a rotor 58, and a ball 60 is provided between (specifically, the lid 26) of the spring 56, the rotor 58, and the ball 60 to electrically connect the two to each other, whereby the beam current flowing to the holder 8 is Current measuring device 64 via holder support arm 22 and leads 62 connected thereto (specifically to its lid 24)
I am trying to measure it by taking it to.

In that case, when the beam current of the ion beam 4 is not so small, the structure as described above does not cause any problem, but ion implantation is performed with a minute current (for example, nA order) and while rotating the wafer 4 (that is, the holder 8). If you do
There is still room for improvement in that the beam current being measured may be affected by noise and the beam current measurement rule may not be accurately performed.

This is because the grease etc. applied to the bevel gears 40-45 becomes an insulator and the electrical contact becomes unstable between the gears meshing during the rotation of the bevel gears 40-45, which becomes a noise source. is there.

Therefore, the main object of the present invention is to provide an ion processing apparatus in which such a point is further improved.

[Means for achieving the purpose]

The ion treatment apparatus of the present invention electrically connects each rotating shaft to the holder supporting arm between one end of the holder rotating shaft and the transmitting rotating shaft at the same electric potential as the holder and the holder supporting arm. Each has a contact,
In addition, each contactor has a conductive ball case inserted and fixed in a portion of the holder support arm that faces one end of each rotation shaft, a conductive coil spring fitted in the ball case, and the coil spring. And a conductive ball elastically pressed against the end face of the rotating shaft.

[Action]

The holder rotation shaft and the transmission rotation shafts are electrically connected to the holder support arm by the contacts, so that the holder rotation arm and the transmission rotation shaft are not electrically unstable. Therefore, even if the electrical contact between the gears for connecting the rotary shafts becomes unstable, noise does not occur.

〔Example〕

FIG. 1 is a longitudinal sectional view partially showing an ion treatment apparatus according to an embodiment of the present invention. The same or corresponding parts as those in the example of FIG. 3 are designated by the same reference numerals, and the differences from the preceding example will be mainly described below.

In this embodiment, the transmission rotary shaft 3 as described above, which is in the beam current measuring system, that is, at the same electric potential as the holder 8.
6, 37 and each one end of the holder rotating shaft 38 and the holder supporting arm 22 (more specifically, its lids 24 to 26), each rotating shaft 36.
Contact for electrically conducting ~ 38 to holder support arm 22
66 to 68 are provided respectively.

Since each of the contacts 66 to 68 has the same structure, the detailed structure of the contact 68 will be described here with reference to FIG. 2 by taking the contact 68 as an example. The end portion is extended to the vicinity of the lid 26, and the ball case 72 is inserted and fixed in a portion of the lid 26 facing the end portion of the holder rotation shaft 38, and a coil spring (more specifically, a compression coil spring) is inserted therein. 74
The ball 70 is attached to form the contact 68, and the ball 70 is elastically pressed against the end surface of the holder rotation shaft 38 by the coil spring 74.

Since the ball case 72, the coil spring 74, and the ball 70 are intended to electrically connect the holder rotating shaft 38 and the lid 26, all of them are conductive ones, for example, metal ones.

In this case, the ball 70 is in point contact with the end surface of the holder rotation shaft 38, and since it is only for electrical conduction, it is not necessary to apply a large force to the ball 70, so that the ball 70 and the end surface of the holder rotation shaft 38 do not contact each other. Friction and wear at the contact points are very small, so there is no need to apply grease or oil to the ball 70.

Therefore, the holder rotation shaft 38 is surely conducted to the lid 26, that is, the holder support arm 22 via the ball 70, the coil spring 74, and the ball case 72, so that it is not electrically unstable. Absent. The same applies to the transmission rotary shafts 36 and 37 side. Also bevel gears attached to them
Since 40 to 45 are surely conducted to the holder support arm 22 via the rotary shafts 36 to 38, respectively, they are not electrically unstable.

Therefore, even if electrical contact between gears that are meshed with each other becomes unstable due to grease or the like during the rotation of the bevel gears 40 to 45, this does not become a noise source and no noise is generated.

As a result, even when minute beam current measurement is performed, it is possible to prevent noise from being added to the regular beam current value and accurately perform beam current measurement.

[Effect of device]

As described above, according to the present invention, the holder main shaft, the holder tilt drive source, the holder support arm, the holder rotation shaft, the holder rotation drive source, and the rotation transmission mechanism as described above are provided. The tilt angle can be changed and the holder can be rotated.As a result, the combination of tilt and rotation allows ion beam irradiation not only on the bottom surface of the recesses such as holes and grooves provided on the wafer surface but also on the side walls. It can be carried out.

In addition, a contact is provided between each end of the holder rotation shaft and the transmission rotation shaft at the same potential as the holder and the holder support arm to electrically connect each rotation shaft to the holder support arm. The shaft and the transmission rotary shafts are electrically connected to the holder support arm by the contacts, respectively, and are not electrically unstable. Therefore, even if the electrical contact between the gears for connecting the rotary shafts becomes unstable, noise does not occur. As a result, even when a minute beam current is measured, noise can be prevented from being added to the regular beam current value, and accurate beam current measurement can be performed.

Moreover, since all the components that make up each contact, that is, the ball case, the coil spring, and the ball, are arranged on the axis of the end of each rotating shaft, the space required for the contact is very small. I'm done. In particular, since the holder support arm is clogged with many parts such as a rotary shaft and gears, it is difficult to allocate a large space to the contactor, so that the contactor having the above-described configuration has a great effect.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view partially showing an ion treatment apparatus according to an embodiment of the present invention. FIG. 2 is an enlarged partial sectional view of one of the contacts of FIG. FIG. 3 is a longitudinal sectional view partially showing an example of the ion processing apparatus which is the background of the present invention. 2 ... Wafer, 4 ... Ion beam, 6 ... Vacuum container, 8 ... Holder, 12 ... Holder tilt motor, 20 ... Holder spindle, 22 ... Holder support arm, 32 ... Holder rotation motor, 36, 37 ... Transmission rotation shaft, 38 … Holder rotation axis, 40-45… Bevel gear, 66-68…
Contact, 70 ... Ball, 72 ... Ball case, 74 ... Coil spring.

Claims (1)

[Scope of utility model registration request] 1. An apparatus for irradiating a wafer with an ion beam in a vacuum container to process the wafer, comprising a holder housed in the vacuum container and capable of holding the wafer, and a holder main shaft penetrating the inside of the vacuum container. And the center line of the holder spindle is connected to the outside of the vacuum container, and a reversible holder tilt drive source for rotating the holder spindle is connected to the holder spindle. A hollow holder support arm that is insulated from the inside of the vacuum container, a holder rotation shaft that is rotatably supported by the holder support arm and has a holder attached to one end, and a holder main shaft that is supported outside the vacuum container. The holder rotation drive source for rotating the holder and the holder rotation arm accommodates the rotation movement from the holder rotation drive source and transmits it to the holder rotation shaft. And a holder supporting arm having the same electric potential as the holder and one end of the transmission rotating shaft, and a holder supporting arm. And a contactor that electrically connects each rotation shaft to the holder support arm, and each contactor is inserted and fixed in a portion of the holder support arm facing one end of each rotation shaft. An ion having a conductive ball case, a conductive coil spring fitted in the ball case, and a conductive ball elastically pressed against the end surface of the rotating shaft by the coil spring. Processing equipment.