JPH0317947A - Ion implanting device - Google Patents

Abstract

PURPOSE:To carry out measuring of uniformity of an ion beam in its scanning direction simultaneously with ion implantation toward a target by causing the ion beam scanned to be incident on the target and a beam meter alternately at a predetermined cycle. CONSTITUTION:A deflecting means 18 for deflecting an ion beam 2 in the Y direction and causing it to be incident on a beam meter 22, and a controller 26 having a function of causing the ion beam 2 scanned by a scanning means 4 to be incident on a target 8 and a beam meter 22 alternately at a predetermined cycle by control of the deflecting means 18, are provided. Thus the ion beam 2 scanned can be made to be alternately incident on the target 8 and the beam meter 22 at a predetermined cycle and so measuring of uniformity of the ion beam in the X direction is carried out simultaneously with ion implantation toward the target 8.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention electrically scans an ion beam and
Mechanically scanning the target in a direction perpendicular to it;
The present invention relates to a so-called hybrid scan type ion implantation device.

[Conventional technology]

A conventional example of this type of ion implantation apparatus is shown in FIG.

In this ion implantation apparatus, a spot-shaped ion beam 2 that has been extracted from an ion source and subjected to mass analysis, acceleration, etc. as necessary is transmitted to a scanning voltage ( For example 1000Hz
A set of scanning electrodes 4 to which a triangular wave voltage of approximately 100 msec. .

On the other hand, a target (for example, a wafer) 8 is held within the irradiation area of the ion beam 2 by a holder 10, and
A drive device 12 drives them in a direction in the direction of Y, which is perpendicular to the X direction.
Mechanically scan in a direction (for example, vertical direction; the same applies hereinafter),
This and the scanning of the ion beam 2 work together to uniformly implant ions over the entire surface of the target 8.

More specifically, the amount of the ion beam 2 that has entered the target 8 and the holder 10 is measured by the beam current measuring device 14, and based on the measurement, the control device 16 controls the driving device l2 to scan the target 8 and the holder 10. The speed is controlled (simply put, if the beam current is large, the scanning speed is increased). The drive device 12 may be a combination of, for example, a motor and a ball screw.

[Problem to be solved by the invention]

However, in the above-mentioned ion implanter, X
It is not known whether the ion beam 2 scanned in the direction is uniformly implanted into the target 8.

In reality, the ion beam 2 that has been scanned and is incident on the target 8 can be There is no guarantee that it will always be injected in the same way on target 8.

Therefore, in order to measure the uniformity of the ion beam 2, a method has been proposed in which a beam measuring device is inserted into the scanned ion beam 2 and moved within the irradiation area of the ion beam (for example, (Refer to Publication No. 62-295347), measurement by such means is based on target 8
Since this can only be done between ion implantations, it is still unclear whether the uniformity of the ion beam 2 in the X direction is good during actual implantation.

Therefore, the main object of the present invention is to provide an ion implantation apparatus that can measure the uniformity of an ion beam in the scanning direction in parallel with ion implantation into a target.

[Means to solve the problem]

In order to achieve the above object, the ion implantation apparatus of the present invention is provided on the side of the target in the Y direction,
a beam measuring instrument for measuring the uniformity of the ion beam in the X direction; and a deflecting means provided downstream of the scanning means for deflecting the ion beam in the Y direction and making it incident on the beam measuring instrument. and a control device having a function of controlling the deflection means and causing the ion beam scanned by the scanning means to be incident on the target and the beam measuring device at a predetermined period.

[Effect]

According to the above structure, the ion beam scanned by the scanning means can be made to be incident on the target and the beam measuring device while being switched at a predetermined period.

Therefore, the uniformity of the ion beam in the scanning direction can be measured in parallel with the ion implantation into the target.

〔Example〕

FIG. 1 is a diagram partially showing an ion implantation apparatus according to an embodiment of the present invention. The same reference numerals are given to the same or corresponding parts as in the example of FIG. 4, and the differences from the conventional example will be mainly explained below.

In this embodiment, the holder 10 and the target 8 are placed above the target 8 on the holder 0 (but may also be placed below), and slightly behind the holder 10 and the target 8 (but in front) so as not to interfere with the mechanical scanning of the holder 10 and the target 8. A beam measuring device 22 is provided to receive the ion beam 2 scanned in the X direction and measure the uniformity of the ion beam 2 in the X direction.
I am trying to input it to 4.

Further, a set of deflection electrodes 18 is provided on the downstream side of the scanning electrode 4 as an example of deflection means for deflecting the ion beam 2 scanned in the X direction in the Y direction and making it incident on the beam measuring device 22. , a constant deflection voltage (DC voltage) is supplied thereto from a deflection power supply 20.

Further, a control device 26 is provided which has a function of controlling the deflection power supply 20 and causing the ion beam 2 scanned by the scanning electrode 4 to be incident on the target 8 and the beam measuring device 22 at predetermined intervals. This control device 26 is
This embodiment also has a function to control the entire ion implantation device. In this example, the beam measuring device 22 is, as shown in FIG.
A large number of Faraday cups 223 each having the same area are arranged in a row in the X direction to receive the ion beam 2 and measure its beam current, and an opening is provided in front of the Faraday cups 223 at a position corresponding to each Faraday cup 223. A mask 221 is provided in front of the sublessor 222 for suppressing secondary electrons and has an opening at a position corresponding to each Faraday cup 223. 2
24 and 225 are supporting insulators. In this example, as shown in FIG.
a current/frequency converter 242 that converts into a frequency signal;
Thereafter, a counter 243 counts the frequency of the output frequency signal, digitizes the beam current I, and supplies it to the arithmetic control circuit 244.
23 to connect it to the current/frequency converter 242, and the beam current M (charge 1!) incident on each Faraday cup 223 based on the data input as described above. k) and an arithmetic control circuit 244 having a function of calculating the uniformity of the ion beam 2 in the X direction by examining the dispersion of the ion beam 2.

In addition, in this embodiment, the following measures are taken to not only measure the uniformity of the ion beam 2 in the X direction but also to further improve the uniformity, but this is essential. isn't it.

That is, the scanning power supply 6 is, for example, as shown in FIG.
An arbitrary waveform generator 61 capable of generating a scanning signal VS of an arbitrary waveform including a triangular wave, and a scanning signal v from the arbitrary waveform generator 61
S is boosted to generate scan voltages X and -vX with mutually opposite polarities.
It is configured using high voltage amplifiers 62 and 63, which respectively output .

Then, the arbitrary waveform generator 61 basically outputs a triangular wave scanning signal VS, and then the ion beam 2
If a predetermined uniformity cannot be obtained, the arbitrary waveform generator 61 is controlled by the processing device 24 to correct the waveform of the scanning signal vS and, ultimately, the scanning voltage generator X so as to improve the uniformity. There is. More specifically, the waveform is corrected so that the scanning speed of the ion beam 2 is high in areas where the amount of beam current is large, and the scanning speed of the ion beam 2 is low in areas where the amount of beam current is small.

An example of the operation of this ion implantation device will be explained as follows.

First, the control device 26 issues a command to the deflection power source 20 to deflect the ion beam 2 and make it incident on the beam measuring device 22. After that, the scanning power source 6 is instructed to deflect the ion beam 2 in the X direction by, for example, A command to scan twice (one way or round trip is fine) is issued. As a result, the ion beam 2 scanned in the X direction is incident on the beam measuring device 22, and its uniformity in the X direction is calculated in the processing device 24.

The processing device 24 then compares the calculated uniformity value with a predetermined set value, and if the uniformity is satisfied, the control device 24
6, outputs an injection OK signal.

In response, the control device 26 instructs the deflection power source 20 to make the ion beam 2 enter the target 8, and further instructs the scanning power source 6 and the control device 16 to perform the implantation operation.

After performing the implantation operation for a while, for example, scanning the ion beam 2 10 times, the ion beam 2 is transferred to the beam measuring device 2.
2 and return to the state where the uniformity is examined.

Thereafter, the above operations are repeated until the predetermined injection into the target 8 is completed.

As described above, in the ion implantation apparatus of this embodiment, the scanned ion beam 2 is transferred to the target 8 and the beam measuring device 22.
Since the ion beam can be switched at a predetermined period to be incident, the uniformity of the ion beam 2 in the X direction can be measured in parallel with the ion implantation into the target 8. In other words, ion implantation can be performed while monitoring the uniformity of the ion beam 2 in the X direction. As a result, for example, abnormalities in injection uniformity can be detected early and in near real time.

Further, if a means for correcting the waveform of the scanning voltage outputted from the scanning power source 6 is further provided as in this embodiment, ion implantation with good implantation uniformity can be performed at all times.

In the above embodiment, the scanning electrode 4 is used as a scanning means for the ion beam 2, and the deflection electrode 18 is used as a deflection means for the ion beam 2, but instead of these, a deflection magnet is used to direct the ion beam 2 in a magnetic field. Alternatively, the scanning and deflection may be performed by the following.

In addition, in this specification, the X direction and the Y direction only represent two orthogonal directions, and therefore, for example, whether the X direction is viewed as a horizontal direction, a vertical direction, or even a direction tilted from them. You can also look at it as

〔Effect of the invention〕

As described above, according to the present invention, since the scanned ion beam can be switched between the target and the beam measuring device at a predetermined period, the uniformity of the ion beam in the scanning direction can be controlled by the ion implantation into the target. Can be measured in parallel. In other words, ion implantation can be performed while monitoring the uniformity of the ion beam in the scanning direction.

As a result, for example, abnormalities in injection uniformity can be detected early and in near real time.

[Brief explanation of drawings]

FIG. 1 is a diagram partially showing an ion implantation apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing a more specific example of the beam measuring device and processing device shown in FIG. 1. FIG. 3 is a block diagram showing a more specific example of the scanning power supply shown in FIG. 1. FIG. 4 is a diagram partially showing an example of a conventional ion implantation apparatus. 2...Ion beam, 4... Scanning electrode (scanning means)
, 6... Scanning power supply, 8... Target, 12...
Drive device, 18... Deflection electrode (deflection means), 20...
- Deflection power source, 22... Beam measurement device, 24... Processing device, 26... Control device. Figure 2 Figure 4 Figure 3

Claims (1)

[Claims] (1) In an ion implantation apparatus in which the ion beam is electrically scanned in the X direction by a scanning means, and the target is mechanically scanned in the Y direction perpendicular to the X direction by a drive device, the target is scanned in the Y direction. A beam measuring device is provided on the side of the ion beam to measure the uniformity of the ion beam in the X direction, and a beam measuring device is provided downstream of the scanning device to deflect the ion beam in the Y direction. a control device having a function of controlling the deflection means to cause the ion beam scanned by the scanning means to be incident on the target and the beam measuring device at a predetermined period. An ion implantation device comprising: