JPH08220299A - Target holding device - Google Patents

Abstract

PURPOSE: To form a complicated irradiation pattern by applying the constitution that a target is made to perform action expressed as the sum of vectors of the rotation of a holder and the rotation of a turntable, and the ion beam action is combined with a beam scan. CONSTITUTION: Ions generated in an ion source 13 are accelerated with an acceleration section 14 and turn into an ion beam I. This ion beam I is deflected at a separation and scanning section 15 and directed toward a target T. At the same time, the ion beam 1 is horizontally scanned at a constant speed. Also, the scanning process takes place unidirectionally from a center section to an end section. Thereafter, the ion beam I is neutralized at a neutralizing section 19, and turns into an atomic beam A. This beam A advances straight and is applied on the target T mounted on a turntable 1. In this case, the turntable 1 rotates in an arrow (a) direction, and a target holder 2 rotates in an arrow (b) direction, respectively at the same angular velocity, Thus, the holder 2 keeps the same attitude relative to a static system at all times. As a result, the uniformity of irradiation can be properly maintained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a beam irradiation device such as an ion beam implanter or a high speed atom beam implanter used for implanting a dopant in manufacturing a semiconductor device.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, so-called doping is performed to implant a different element into a substrate in order to form an integrated circuit on the substrate. As a method for this purpose, an ion implantation method is used, and recently, adoption of a high-speed atomic beam implantation method which can avoid various drawbacks of the ion beam implantation has been considered. In order to uniformly dope the entire surface of the semiconductor substrate with these devices, it is necessary to relatively move the substrate in a direction orthogonal to the traveling direction of the beam and scan the target surface with the beam.

As a conventional mechanism for this purpose, a rotary table having a rotary shaft substantially parallel to the beam or having an arbitrary angle for preventing channeling is provided at a beam irradiation position, and the rotary table is provided with a rotary shaft. There is one that fixes a plurality of targets in a certain direction. In such a device,
As shown in FIG. 8, while rotating the turntable 31, the beam is scanned in the radial direction between the center and the edge of the turntable 31 so that impurities are implanted into the entire surface of the target T.

At this time, as a pattern of the combination of the rotation of the rotary table 31 and the speed setting of the scanning of the beam, there are the case where the rotational speed of the rotary table 31 is increased and the beam scanning speed is slowed, and the opposite case. is there. The high speed rotation of the turntable 31 is mechanically limited, and it is theoretically reasonable to scan the beam at a high speed.

[0005]

However, in the conventional method of scanning such a beam at a high speed, the traveling direction of the beam on the target T is inclined as the turntable rotates, and in the case of unidirectional scanning. It becomes radial as shown in FIG. For this reason, in this scanning method which has been used in the above-mentioned conventional method and is not unreasonable in principle, it is difficult to uniformly irradiate the entire surface of the target.

[0006]

The present invention has been made to solve the above-mentioned problems, and the invention of claim 1 has a target holding base for holding a target and is provided on a beam traveling line. A rotating table that rotates about a rotation axis that is almost parallel to the beam line or has an arbitrary angle,
And a rotating mechanism for rotating the target holding table with respect to the rotating table. According to a second aspect of the invention, the rotation mechanism has a transmission mechanism that transmits the rotation of the rotary table to the target holding table.

According to a third aspect of the present invention, the rotating mechanism has a drive device that is mechanically independent of the drive mechanism of the turntable. According to a fourth aspect of the present invention, the rotating mechanism is configured to rotate the target holding table in synchronization with the rotation of the rotating table. According to a fifth aspect of the present invention, there is provided a target holding device having the above structure, a beam source, and a beam scanning mechanism for scanning the target holding device with a beam.

[0008]

According to the invention of claim 1, the target is attached to the target holding table, and the target holding table is provided on the rotating table. Therefore, the target is the sum of the respective vectors of the rotation of the holding table and the rotation of the rotating table. Exercise as In the invention of claim 2, the rotation of the rotary table is transmitted to the target holding table via the rotating mechanism.

In the third aspect of the present invention, the target holding table is driven by a driving device that is mechanically independent of the driving mechanism of the rotary table. In the invention of claim 4, the target holder is rotated in synchronization with the rotation of the rotary table, and therefore the target holder always rotates in the same phase with respect to the stationary system, that is, without changing its posture. In the invention of claim 5, the beam generated in the beam source is scanned by the beam scanning mechanism and is irradiated onto the target held in the target holding device. At the target, the beam irradiator moves along a vector represented as the sum of the three vectors of beam scanning, rotation of the turntable, and rotation of the target holder.

[0010]

1 to 3 show a target holding device H according to one embodiment of the present invention, which has a structure in which a rotary table and a target holding table are mechanically interlocked. The rotary base 1 is provided with four target holding bases 2 at intervals of 90 degrees in the circumferential direction. The holding table 2 is a disk-shaped member mounted in a recess 3 provided at a predetermined position of the rotary table 1, and a recess 5 having a clamp device 4 for fixing the target T is formed on the surface thereof. A rotation shaft 6 is provided on the back surface of the holding table 2, which is rotatably supported by a bearing device (not shown), and a rotation gear 7 is attached to the lower end thereof. The rotating gear 7 meshes with an intermediate gear 8 provided on the lower surface of the rotary table 1, and the intermediate gear 8 meshes with a fixed gear 10 that surrounds a rotary shaft 9 of the rotary table 1. The fixed gear 10 is connected and fixed to a support member (not shown) of the rotary table 1. The planetary gear structure including the rotation gear 7, the intermediate gear 8, and the fixed gear 10 constitutes a transmission mechanism that transmits the rotation of the rotary table to the holding table. Rotating gear 7 and fixed gear 10
Has a gear ratio of 1: 1. Therefore, the rotary base 1 and the holding base 2 are synchronized, and the holding base 2 makes one rotation in the opposite direction while the rotary base 1 makes one rotation. That is, the holding table 2 always keeps the same posture with respect to the ground (stationary system).

FIG. 3 shows an example in which the present invention is applied to a high-speed atomic beam irradiation apparatus. In the figure, reference numeral 11 indicates a substantially L-shaped vacuum chamber, the inside of which is the main pump 1.
It is exhausted by 2 and is kept at a predetermined low pressure. An ion source 13 is provided on one bent side of the vacuum chamber 11.
In the vicinity of the ion source 13, an accelerating unit 14 including an electrode to which a high voltage is applied is provided. A magnetic field is formed in the bent portion of the vacuum chamber 11 by an electromagnet,
As a result, only the desired ions of the ion beam I are deflected in a predetermined direction to be separated from other ions, and the magnetic field strength or the electric field strength is changed to move the ion beam in the radial direction of the turntable 1 (in the illustrated example, A separating / scanning unit 15 that scans by shaking is provided.

At the center of the longitudinal portion of the vacuum chamber 11, there is provided a neutralizer N, which comprises three gas cells 1.
It has a neutralization chamber 19 composed of 6, 17, and 18. In these three gas cells, a differential pressure is formed by the turbo molecular pumps 20 and 21, and the central gas cell 17 has a high pressure. The ion beam I exchanges electric charge by contacting with the gas in the atom beam A. Becomes A residual ion removing device 22 that deflects and removes residual ions by magnetic force is provided on the outlet side of the neutralization chamber 19.

Since the ion beam I is scanned left and right as described above, a mechanism for changing the position of the narrowed portion (opening) 23 provided in the gas cell of the neutralization chamber 19 may be provided. Also, the narrowed portion 23 may be formed with a certain length in that direction. Also, in this figure, the direction in which the residual ions are removed does not correspond to the arrangement of the magnets, but this is for convenience of illustration. The target holding device H described above is provided at the other end of the vacuum chamber 11.

Next, the operation of the high-speed atomic beam irradiation apparatus constructed as above will be described. Ions generated in the ion source 13 are accelerated by the accelerating unit 14 to become an ion beam I, which is deflected in the separating / scanning unit 15 to be directed toward the target and, at the same time, is horizontally scanned at a constant speed. . In this example, the scanning is performed in a so-called sawtooth shape with one-way passage from the vicinity of the center toward the edge. The ion beam I is neutralized in the neutralization unit 19 to become an atomic beam A, which travels straight and is applied to a target T attached to the rotary table 1.

Here, as shown in FIG. 4, since the rotary table 1 rotates in the direction of arrow a and the target holder 2 rotates in the direction of arrow b at the same angular velocity in synchronization, the table 2 is always stationary. Take the same attitude against. Therefore, the beam irradiation pattern becomes parallel as shown in FIG. In this figure, the direction of the beam pattern is horizontal when the ratio of the scanning speed of the beam and the rotation speed of the rotary base 1 is large, but when the speed ratio is smaller, the pattern tilts upward to the left. However, since the inclination angle is constant, it remains parallel. Since the beam irradiation patterns are parallel, the irradiation uniformity can be ensured by a simple method of setting the pitch of the irradiation pattern in accordance with the tolerance.

In this apparatus, a method of increasing the rotation speed of the rotary table 1 and decreasing the beam speed can be adopted. In this case, a concentric irradiation pattern has been used in the past, but with this apparatus, a parallel linear pattern is formed, so that it is easy to ensure uniformity.

FIGS. 6 and 7 show another embodiment of the present invention, in which the rotation shaft 6 of each target holding base 2 is rotated.
A drive motor 24 is provided on the lower end side of the. The motor 24 is connected to a control device (not shown) and is controlled so as to rotate in synchronization with the rotary shaft 9 of the rotary base 1 as shown in FIG. In this example, the motor 24 is provided on each holding table 2, but a drive motor may be attached to a predetermined position of the rotary table 1 and a transmission mechanism that links this with the shaft of each holding table 2 may be provided. In any case, it is not necessary to rotate all the holding bases 2 at the same time, and they may be rotated intermittently only when they are in the beam irradiation position.

Further, in the embodiments of FIGS. 6 and 7, since the rotations of the rotary table 1 and the holding table 2 can be controlled completely independently, not only the parallel irradiation pattern as described above but also a desired irradiation beam pattern can be obtained. A suitable rotation speed control pattern can be set. For example, it is possible to rotate the holder 90 degrees at the end of one scanning to control the beam irradiation pattern into a grid pattern. In addition to this, an appropriate pattern can be obtained according to the next process. It can be controlled.

Although the above embodiment has described the apparatus for irradiating an atomic beam, the present invention is not limited to this, and other beam irradiating apparatuses such as an ion beam irradiating apparatus conventionally used can be used. It may be applied, and not only semiconductor manufacturing equipment, but also sputtering equipment,
It can be applied to various devices using a beam, such as an etching device and a beam processing device.

[0020]

As described above, according to the first aspect of the present invention, the target moves as the sum of the respective vectors of the rotation of the holding table and the rotation of the rotating table.
This can be combined with beam scanning to form a more complicated irradiation pattern, and the degree of freedom in designing and using the beam irradiation device can be increased. According to the invention of claim 2, since the rotation of the rotary table is transmitted to the target holding table via the rotary mechanism, the rotary drive source of the rotary table can be used as it is, and the mechanical transmission mechanism can be used for both of them. Interlocking is secured.

According to the third aspect of the present invention, since the target holding table is driven by a driving device that is mechanically independent of the driving mechanism of the rotating table, an irradiation pattern suitable for the purpose and situation of the device is used. Obtainable. According to the invention of claim 4, since the target holder rotates without changing its posture with respect to the stationary system, when the beam scanning is linear, the irradiation pattern is also linear and the entire surface of the target is uniform. It is easy to process. According to the invention of claim 5, it is possible to obtain a beam irradiation device that exhibits the above-described effects.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a target holding device according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a target holding device according to the first embodiment of the present invention.

FIG. 3 is a schematic view of a beam irradiation device using the target holding device according to the first embodiment of the present invention.

FIG. 4 is a diagram for explaining the operation of the target holding device according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a beam irradiation pattern when the target holding device according to the first embodiment of the present invention is used.

FIG. 6 is a sectional view showing a target holding device according to a second embodiment of the present invention.

FIG. 7 is a plan view showing a target holding device according to a second embodiment of the present invention.

FIG. 8 is a diagram illustrating the operation of a conventional target holding device.

FIG. 9 is a diagram showing a beam irradiation pattern when a conventional target holding device is used.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotary table 2 holding table 6 rotating shaft 7 rotating gear 8 intermediate gear 10 fixed gear 13 ion source 15 separation / scanning section 24 drive motor A atomic beam I ion beam H holding table T target

Claims (5)

[Claims] 1. A rotary table having a target holding table for holding a target, the rotary table rotating on a traveling line of a beam around a rotation axis substantially parallel to the beam line or having an arbitrary angle, and the target holding table. A target holding device, comprising: a rotating mechanism for rotating the rotating table. 2. The target holding device according to claim 1, wherein the rotation mechanism has a transmission mechanism that transmits the rotation of the turntable to the target holding table. 3. The target holding device according to claim 1, wherein the rotating mechanism has a driving device that is mechanically independent of a driving mechanism of the rotating table. 4. The target holding apparatus according to claim 1, wherein the rotating mechanism rotates the target holding table in synchronization with the rotation of the rotating table. 5. A beam irradiation apparatus comprising: the target holding device according to claim 1; a beam source; and a beam scanning mechanism for scanning the target holding device with a beam. .