JP3409398B2 - Ion implanter, method of operating ion implanter, and method of adjusting beam deflection angle of ion implanter - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to an ion implantation apparatus for irradiating a wafer by scanning the ion beam, ion implantation device
Operating method and adjustment of beam deflection angle of ion implanter
It is about the method .

[0002]

2. Description of the Related Art Conventionally, a hybrid scan type ion implanter is constructed by horizontally and electrostatically or ionically irradiating a vertically reciprocally moved wafer with an ion beam that is horizontally scanned. , The entire surface of the wafer is uniformly irradiated with the ion beam.

In recent years, in order to remove unnecessary impurity ions generated when the ion beam advances and to realize the downsizing of the apparatus, as shown in FIG. 2, one-dimensional scanning with the ion beam 51 in the horizontal direction is performed. As a device provided downstream of the scanner 52, for example, a neutral trap 54 may be adopted which collimates the ion beam 51 in the direction of the wafer 53 by electromagnetic force and collimates the ion beam 51. The specifications of the neutral trap 54 are determined in advance so as to collimate the ion beam 51 scanned by the one-dimensional scanner 52, and the ion species and the energy of the ion beam 51 are adjusted during adjustment before ion implantation. The exciting current corresponding to the neutral trap 5
4, the ion beam 51 is deflected in the direction of the wafer 53, and the ion beam 51 is irradiated onto the surface of the wafer 53 at a predetermined incident angle (beam injection angle).

[0004]

However, the above-mentioned conventional neutral trap 54 is used for the ion beam 51.
In the ion implantation apparatus for collimating the ion beam 51, when the ion beam 51 is deflected by the exciting current calculated based on the set value, it is difficult to obtain the ion beam 51 passing through the regular path due to the hysteresis characteristic and the like. Ion implantation will be performed at an incident angle α different from the incident angle α. That is, the conventional ion implanter has reduced accuracy of the incident angle, and even when the entire surface of the wafer 53 is uniformly irradiated with the ion beam 51 collimated by the neutral trap 54, a predetermined amount of the ion beam 51 is emitted. There is a problem that ions cannot be injected into a predetermined position of the wafer 53 at a predetermined angle with high accuracy.

Therefore, it is an object of the present invention to provide an ion implanter capable of solving the above problems by improving the accuracy of the angle of incidence of the ion beam 51 on the surface of the wafer 53.

[0006]

In order to solve the above-mentioned problems, the ion implantation apparatus of the present invention collimates a scanned ion beam while deflecting it in the wafer direction and collimates the ion beam so that a predetermined incident angle with respect to the wafer surface is obtained. The wafer is irradiated with the ion beam so as to have the following characteristics.

That is, the ion implantation apparatus is a one-dimensional scanner that scans the ion beam on one side of a straight trajectory of the ion beam, and a beam scanning unit that deflects the ion beam that has passed through the beam scanning unit. and a deflection collimating means is a neutral traps, waiting
The ion beam that went straight through the beam scanning means in the state
The deflection parallelizing means is arranged so as to deflect
It Further, the ion implantation apparatus is configured so that, when an ion beam that has traveled straight through the beam scanning means is deflected by the deflection collimating means and is incident, the traveling direction of the ion beam has a predetermined incident angle with respect to the wafer surface. It is characterized in that it further comprises a beam detecting means which is a beam detector disposed in the.

Further , a method of operating the ion implantation apparatus of the present invention.
Deflects the scanned ion beam in the wafer direction.
Ion implanter for parallelizing and irradiating the wafer
Therefore, it should be on one side of the straight trajectory of the ion beam.
Beam scanning means for scanning the ion beam with the beam
Deflection and parallelization of the ion beam that has passed through the scanning unit
Deflection and collimation means for
Beam detection means for outputting the emitted beam current
Method of operating a that ion implantation apparatus, Lee to Parkway Ha
When stopping the on-beam irradiation,
While maintaining the deflection of the ion beam by the ionization means,
Put the ion beam in the standby state with the beam scanning means.
It is characterized in that it is incident on the beam detecting means.

Further , the beam deflection of the ion implantation apparatus of the present invention is
The direction adjustment method is to scan the ion beam on the wafer.
Predetermine with respect to the wafer surface by deflecting in parallel
The wafer is irradiated with the ion beam so that the angle of incidence becomes
It is an ion implanter that makes the ion beam go straight
Beam that scans the ion beam in one direction side than
The scanning means and the ion beam that has passed through the beam scanning means.
And a deflecting and collimating means for deflecting and collimating the beam.
In the method of adjusting the beam deflection angle of the implanter,
The beam is deflected by the deflection collimating means and is incident.
The direction of travel of the ion beam with respect to the wafer surface
A beam detecting means arranged so as to have a predetermined incident angle.
The ion implanter further has the beam scanning means.
While holding the
Change the beam deflection angle,
The maximum beam current detected when the ion beam is incident is
Ion beam by the deflection parallelizing means
It is characterized by adjusting the deflection angle of.

Method for adjusting beam deflection angle of the above ion implantation apparatus
In the method, the deflection parallelizing means is
A magnetic field is generated and the ion beam is polarized according to the magnetic field strength.
Change the exciting current of the deflection parallelizing means.
When the ion beam is incident on the
Excitation when the beam current detected at the stage reaches the maximum value
It is possible to determine the magnetic current as the exciting current during ion implantation.
desirable.

[0011]

According to the above structure, the incident angle of the ion beam with respect to the wafer surface is adjusted to a predetermined angle by adjusting the deflecting and collimating means using the ion beam used for ion implantation. It is possible. Therefore, since the accuracy of the incident angle can be improved, a predetermined amount of impurity ions can be accurately injected into a predetermined position of the wafer. Furthermore, without considering the ion species and energy of the ion beam,
Since the ion beam can be made incident on the beam detecting means by adjusting the deflecting and collimating means, the incident angle of the ion beam with respect to the wafer surface can be easily adjusted.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following will describe one embodiment of the present invention with reference to FIG.

As shown in FIG. 1, the ion implantation apparatus according to this embodiment produces a magnetic field to produce an ion beam 1
Has a mass analyzer 3 for mass spectrometric analysis to obtain desired impurity ions. An ion source (not shown) that generates the ion beam 1 and an accelerator (not shown) that accelerates the mass-analyzed ion beam 1 are provided in front of and behind the mass analyzer 3, respectively. A one-dimensional scanner 2 that electromagnetically deflects the ion beam 1 in a horizontal direction, for example, is provided at the subsequent stage of the accelerator. The one-dimensional scanner 2 performs a standby operation of moving the ion beam 1 straight and an ion beam 1 of the ion beam 1. By repeatedly increasing and decreasing the deflection angle, the ion beam 1
The scanning operation for scanning the ion beam 1 in the horizontal direction is performed on the one direction side of the straight trajectory of the.

A neutral trap 4 for electromagnetically deflecting the ion beam 1 is provided after the one-dimensional scanner 2. This neutral trap 4
The traveling direction of the deflected ion beam 1 determined by the ion beam 1 traveling straight through the one-dimensional scanner 2 and being deflected, and the traveling direction of the ion beam 1 scanned by the one-dimensional scanner 2 after being deflected Are parallelized so that they are in the same direction. The one-dimensional scanner 2 described above may be configured to electrostatically deflect the ion beam 1.

In the deflection direction of the ion beam 1 deflected by the neutral trap 4 described above, the ion beam 1
A beam detector 5 for determining the deflection angle of the wafer, a platen (not shown) for holding the wafer 6 and reciprocating in the vertical direction, and a dose Faraday 7 used for controlling the moving speed of the wafer 6 by the platen. Has been done.

The beam detector 5 is the ion beam 1
Is arranged so that the incident angle of the ion beam 1 with respect to the surface of the wafer 6 becomes a predetermined incident angle such as a right angle, when it advances straight through the one-dimensional scanner 2 during standby operation and is deflected by the neutral trap 4. ing. In addition, the beam detector 5 is located at a position sufficiently separated from the beam scanning area so as not to obstruct the loading and unloading when the wafer 6 is loaded on the platen and when the wafer 6 is unloaded from the platen. It is arranged. still,
The beam detector 5 is preferably movable so that the incident angle of the ion beam 1 with respect to the wafer 6 surface can be arbitrarily set.

The beam detector 5 is connected to a beam deflection angle adjusting device 8 and outputs a beam current detected when the ion beam 1 is incident on the beam detector 5 to the beam deflecting angle adjusting device 8. It is supposed to do. The beam deflection angle adjusting device 8 is connected to the neutral trap 4 and determines the exciting current of the neutral trap 4 based on the beam current. That is, the beam deflection angle adjusting device 8 changes the deflection angle of the ion beam 1 by gradually increasing the exciting current of the neutral trap 4 during the standby operation of the one-dimensional scanner 2 to change the deflection angle of the ion beam 1 to a beam detector. 5, the exciting current when the beam current of the beam detector 5 reaches the maximum value is determined as the exciting current at the time of ion implantation.

The operation of the ion implanter having the above structure will be described.

First, when the ion implantation apparatus is started up, power supply to the ion source, the mass analyzer 3, and the accelerator is started. As a result, positively charged ions are extracted from the ion source by the extraction electrode, and the ion beam 1 composed of only the specific impurity ions mass-analyzed by the mass analyzer 3 is generated. After being accelerated by the accelerator, the ion beam 1 travels straight through the one-dimensional scanner 2 that is in the standby state, and travels straight through the neutral trap 4 to which the exciting current is not supplied.

Next, the exciting current of the neutral trap 4 is energized by the command of the beam deflection angle adjusting device 8 and a magnetic field is generated in the neutral trap 4.
As a result, the ion beam 1 that has passed straight through the neutral trap 4 is deflected toward the beam detector 5 at a deflection angle according to the magnetic field strength of the neutral trap 4. The energization amount of the exciting current to the neutral trap 4 is gradually increased by the command of the beam deflection angle adjusting device 8, and the deflection angle of the ion beam 1 is gradually increased as the energizing amount of the exciting current is increased. It will change. Then, the ion beam 1 is incident on the beam detector 5, and the exciting current when the beam current detected by the beam detector 5 shows the maximum value is determined as the exciting current at the time of ion implantation.

After that, while the exciting current to the neutral trap 4 is maintained, the beam amount of the ion beam 1 is appropriately changed by referring to the beam current from the beam detector 5 to change the operating conditions of the ion source. After being adjusted to a predetermined value, the scanning operation of the one-dimensional scanner 2 is started, so that the ion beam 1 is horizontally scanned by the one-dimensional scanner 2 and the neutral trap 4 is moved.
Will pass through.

At this time, the neutral trap 4 has a direction in which the traveling direction of the ion beam 1 that has traveled straight through the one-dimensional scanner 2 is deflected and the traveling direction of the scanned ion beam 1 is deflected. It is designed to be parallelized so that. Further, in the beam detector 5, when the ion beam 1 traveling straight on the one-dimensional scanner 2 in the standby operation is deflected by the neutral trap 4 and enters, the incident angle of the ion beam 1 with respect to the wafer 6 surface becomes, for example, a right angle. Are arranged as follows. As a result, the ion beam 1 that has passed through the neutral trap 4 scans the wafer 6 surface at an incident angle that is perpendicular to the wafer 6 surface.

Next, when the irradiation of the ion beam 1 to the wafer 6 is stopped due to the completion of ion implantation or the abnormality of the apparatus, the one-dimensional scanner 2 waits while the exciting current to the neutral trap 4 is maintained. Will be put into operation. The one-dimensional scanner 2 in the standby operation moves the ion beam 1 straight, and the ion beam 1
Is deflected by the magnetic field of the neutral trap 4 and enters the beam detector 5. As a result, the beam detector 5 exhibits a function as a beam parking station which is a retreat place for the ion beam 1 when the ion implantation is not performed. In the example,
After the implantation is completed, the ion beam 1 is made to stand by at the beam parking position, the implanted wafer is taken out, then the unimplanted wafer is loaded, the beam standby is terminated, and the implantation irradiation is restarted.

As described above, the ion implantation apparatus of this embodiment has a one-dimensional scanner 2 that scans the ion beam 1 on one side of the linear trajectory of the ion beam 1, and the ion beam 1 that has passed through the one-dimensional scanner 2. When a neutral trap 4 for deflecting and collimating the ion beam 1 and an ion beam 1 traveling straight through a one-dimensional scanner 2 are deflected by the neutral trap 4 and incident, the traveling direction of the ion beam 1 is predetermined with respect to the wafer 6 surface. The beam detector 5 is arranged so as to have an incident angle of.

As a result, the ion beam 1 straightly moved by the one-dimensional scanner 2 is made incident on the beam detector 5.
By adjusting the deflection angle of the ion beam 1 by the neutral trap 4, it is possible to adjust the incident angle of the ion beam 1 with respect to the surface of the wafer 6.
That is, it is possible to adjust the incident angle of the ion beam 1 with respect to the wafer 6 surface using the ion beam 1 used for ion implantation. Therefore, since the ion implantation apparatus can improve the accuracy of the incident angle, it becomes possible to precisely implant a predetermined amount of impurity ions into a predetermined position of the wafer, and as a result, the implantation accuracy and implantation can be improved. It is possible to improve quality.
Further, since the ion trap 1 can be made incident on the beam detector 5 by adjusting the neutral trap 4 without considering the ion species and energy of the ion beam 1, the incident angle of the ion beam 1 with respect to the surface of the wafer 6 can be adjusted. It is possible to easily adjust the.

In addition, the above-mentioned ion implanter maintains the excitation current to the neutral trap 4 to maintain the deflection of the ion beam 1 by the neutral trap 4 when the irradiation of the ion beam 1 is stopped. The scanner 2 is set in a standby state and the ion beam 1 is allowed to go straight. Thereby, the beam detector 5
Is the ion beam 1 when ion implantation is not performed.
It is possible to give the beam detector 5 a function as a beam parking station, which is an evacuation site.

Further, in the above-mentioned ion implantation apparatus, the beam detector 5 is arranged at a position which does not hinder the loading and the removal when the wafer 6 is loaded on the platen and when the wafer 6 is unloaded from the platen. ing. Therefore, the arrangement of the beam detector 5 does not hinder the transportation of the wafer 6.

[0028]

As described above, the ion implantation apparatus of the present invention collimates a scanned ion beam while deflecting it in the direction of the wafer and collimates the ion beam so that the ion beam has a predetermined incident angle with respect to the wafer surface. is intended to be irradiated to a beam scanning means for scanning the ion beam in one direction side of the straight trajectory of the ion beam, a deflecting collimating means for collimating and deflecting the ion beam passed through the beam scanning means Have the beam scanning hand in the standby state
The deflection is performed so that the ion beam traveling straight through the step is also deflected.
A collimating means is arranged. Also, ion implantation equipment
Is arranged so that, when an ion beam traveling straight through the beam scanning means is deflected by the deflection collimating means and is incident, the traveling direction of the ion beam has a predetermined incident angle with respect to the wafer surface. The configuration further includes a beam detection unit that is a beam detector.

This makes it possible to adjust the deflecting and collimating means by using the ion beam used for ion implantation and adjust the incident angle of the ion beam with respect to the wafer surface to be a predetermined incident angle. The accuracy of the incident angle is improved, and it is possible to inject a predetermined amount of impurity ions into a predetermined position of the wafer with high accuracy. Further, since the ion beam can be incident on the beam detecting means by adjusting the deflection parallelizing means without considering the ion species and energy of the ion beam, it is easy to adjust the incident angle of the ion beam to the wafer surface. The effect is that it can be performed.

The method of operating the ion implantation apparatus of the present invention
Deflects the scanned ion beam in the wafer direction.
Ion implanter for parallelizing and irradiating the wafer
Therefore, it should be on one side of the straight trajectory of the ion beam.
Beam scanning means for scanning the ion beam with the beam
Deflection and parallelization of the ion beam that has passed through the scanning unit
Deflection and collimation means for
Beam detection means for outputting the emitted beam current
In the method of operating the ion implanter,
When stopping the on-beam irradiation,
While maintaining the deflection of the ion beam by the ionization means,
Put the ion beam in the standby state with the beam scanning means.
It is characterized in that it is incident on the beam detecting means.

Further , the beam deflection of the ion implantation apparatus of the present invention is
The direction adjustment method is to scan the ion beam on the wafer.
Predetermine with respect to the wafer surface by deflecting in parallel
The wafer is irradiated with the ion beam so that the angle of incidence becomes
It is an ion implanter that makes the ion beam go straight
Beam that scans the ion beam in one direction side than
The scanning means and the ion beam that has passed through the beam scanning means.
And a deflecting and collimating means for deflecting and collimating the beam.
In the method of adjusting the beam deflection angle of the implanter,
The beam is deflected by the deflection collimating means and is incident.
The direction of travel of the ion beam with respect to the wafer surface
A beam detecting means arranged so as to have a predetermined incident angle.
The ion implanter further has the beam scanning means.
Io by said deflecting collimating means while the standby state of the
Change the beam deflection angle,
The maximum beam current detected when the ion beam is incident is
Ion beam by the deflection parallelizing means
It is characterized by adjusting the deflection angle of.

Method of adjusting beam deflection angle of the above ion implantation apparatus
In the method, the deflection parallelizing means is
A magnetic field is generated and the ion beam is polarized according to the magnetic field strength.
Change the exciting current of the deflection parallelizing means.
When the ion beam is incident on the
Excitation when the beam current detected at the stage reaches the maximum value
It is possible to determine the magnetic current as the exciting current during ion implantation.
desirable.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a state in which a deflection angle of an ion beam is adjusted by an ion implantation apparatus of the present invention.

FIG. 2 shows a conventional example and is an explanatory view showing a state in which a deflected ion beam is applied to a wafer.

[Explanation of symbols]

1 ion beam 2 One-dimensional scanner (beam scanning means) 3 Mass spectrometer 4 Neutral trap (deflection parallelization means) 5 Beam detector (beam detection means) 6 Waha 7 Dose Faraday 8 Beam deflection angle adjustment device

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01J 37/317 H01J 37/04 H01L 21/265 C23C 14/48

Claims (4)

(57) [Claims] 1. A collimated while deflecting the scanned ion beam in the wafer direction, an ion implantation apparatus for irradiating an ion beam to the wafer so as to have a predetermined angle of incidence with respect to the wafer surface, the ion beam An ion implanter having a beam scanning means for scanning an ion beam on one side of a straight trajectory and a deflection collimating means for deflecting and collimating the ion beam passing through the beam scanning means.
In the standby state, the ion beam is moved straight through the beam scanning means.
The deflection parallelizing means is arranged so as to deflect the beam as well.
Cage, when the ion beam straight through the beam scanning means is incident is deflected by the deflection collimating means, the traveling direction of the ion beam is arranged to have a predetermined angle of incidence with respect to the wafer surface An ion implanter further comprising a beam detecting means. 2. A scanned ion beam is directed to a wafer.
Ions to be collimated and deflected to irradiate the wafer
It is an implanter, and the ions are placed on one side of the straight trajectory of the ion beam.
Beam scanning means for scanning the beam and deflecting the ion beam passing through the beam scanning means
Deflection and collimation means for collimating and outputting the beam current detected when the ion beam is incident.
Operation of an ion implanter with a beam detection means
In the method, when the irradiation of the ion beam to the wafer is stopped
Maintains the deflection of the ion beam by the deflection collimating means.
While lifting by the beam scanning unit in a standby state Io
Beam is incident on the beam detecting means.
And operating method of ion implanter. 3. The scanned ion beam is directed to the wafer.
Parallelize while deflecting, and insert it into the wafer
Irradiate the wafer with an ion beam so that the angle of attack is the same.
An ion implanter, in which ions are placed on one side of the straight trajectory of the ion beam.
Beam scanning means for scanning the beam and deflecting the ion beam passing through the beam scanning means
Of an ion implanter having a deflecting and collimating means for collimating
In the beam deflection angle adjusting method, the ion beam is deflected by the deflection collimating means and enters.
When irradiated, the direction of travel of the ion beam is the wafer surface
A beam detector arranged to have a predetermined incident angle with respect to
The ion implanter further includes a beam ejecting means, and the deflection flattening device is performed while the beam scanning means is in a standby state.
Change the deflection angle of the ion beam
It is detected when the ion beam is incident on the beam detection means.
The above-mentioned deflection parallelizing means so that the beam current generated is maximized.
It is characterized by adjusting the deflection angle of the ion beam by
Method of adjusting beam deflection angle of ion implanter. 4. The beam of the ion implanter according to claim 3.
In the deflection angle adjusting method, the deflection parallelizing means generates a magnetic field by an exciting current.
It deflects the ion beam according to the magnetic field strength.
Ri, by changing the exciting current of the deflection collimating means, Ionbi
Beam detected by the beam detection means when a beam is incident.
Ion implantation of exciting current when the maximum current is reached
Beam polarization characterized by being determined as the excitation current during
Direction adjustment method.