JPH08315762A - Ion implantation device and ion implantation method - Google Patents

Abstract

PURPOSE: To provide an ion implantation device and an ion implantation method by which characteristics of an element formed in a base beard can be uniformed by uniforming ion implantation distances in the specific direction of the base board even when a rotary holder is used. CONSTITUTION: An ion implantation device 1 having a position detecting part 3 to detect a rotary position of a rotary holder 2, a deflecting part 4 to give a prescribed electric field to an ion beam and a control circuit 5 which gives a prescribed signal to the deflecting part 4 on the basis of the rotary position of the rotary holder 2 detected by the position detecting part 3 and controls an incident angle of the ion beam, is provided. When implantation is performed, the rotary position of the rotary holder 2 is detected, and the incident angle of the ion beam is controlled on the basis of this detected rotary position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion implantation apparatus and an ion implantation method for implanting ions at a predetermined angle to a substrate mounted on the periphery of a rotary holder.

[0002]

2. Description of the Related Art An ion implantation apparatus, which is one of semiconductor manufacturing apparatuses, implants ions, which are predetermined impurities, into a substrate such as a silicon wafer to form an element region and the like. Some of these ion implantation devices include a rotary holder that holds a plurality of substrates and performs beam scanning in one direction.

FIG. 3 is a view for explaining the rotary holder.
The rotary holder 2 can be mounted with a plurality of substrates 10 on its periphery and can rotate about a center O. The rotary holder 2 is arranged in a predetermined chamber (not shown). When performing ion implantation, the rotation holder 2 is rotated at a predetermined rotation speed while the substrate 10 is mounted, and the ion beam is applied to a fixed position. To do so. Due to the rotation of the rotary holder 2, mechanical scanning is performed along the rotation direction of the substrate 10 with an ion beam that strikes a fixed position, and predetermined ions are implanted into each substrate 10. The beam scanning in the direction perpendicular to the rotation direction of the substrate 10 is performed by a predetermined deflecting means (not shown).
The angle of incidence of the ion beam on the substrate 10 is preset to about 5 ° to 7 ° from the viewpoint of preventing channeling.

[0004]

However, in ion implantation using such a rotary holder, there is a difference in the implantation distance in a specific direction of the substrate between the impurity region in the central portion of the substrate and the impurity region in the peripheral portion. Will occur. FIG. 4 is a diagram for explaining the trajectory of the ion beam, and FIG. 5 is a diagram for explaining the impurity region. That is, as shown in FIG. 4, when ion implantation is performed using the rotary holder 2 (see FIG. 3), the ion beam is drawn on the substrate 10 in a locus that draws an arc as indicated by a chain line β in the figure. It will be irradiated.

As described above, since the ion beam is provided with an incident angle of about 5 ° to 7 ° in advance from the viewpoint of preventing channeling, the ion beam draws an arc with respect to the substrate 10, For example, a difference occurs between the central portion and the peripheral portion of the substrate 10 in the implantation distance of ions that enter the substrate 10 in a direction along the orientation flat (hereinafter, simply referred to as a lateral direction). FIG. 5A shows FIG.
3 shows the impurity region D in the central portion of the substrate 10 in FIG. In this case, the ion beam is implanted at an incident angle for preventing channeling, and the impurity region D provided between the masks M enters the substrate 10 in the lateral direction by a distance d.

On the other hand, FIG. 5B shows the substrate 10 in FIG.
6 shows an impurity region D'in the peripheral portion of. In the peripheral portion of the substrate 10, since the ion beam draws an arc with respect to the surface of the substrate 10, the component with respect to the horizontal direction of the substrate 10 becomes small even if the ion beam has the same incident angle. The implantation distance of the ions with respect to is shorter than that in the central portion. That is,
The impurity region D ′ provided between the masks M in the peripheral portion is separated by a distance d ′ (d ′ <in the lateral direction of the substrate 10.
Only d) will enter. For this reason, in the ion implantation using the rotary holder 2 (see FIG. 3), the implantation distance of the impurity region in the lateral direction of the substrate 10 is different between the central portion and the peripheral portion of the substrate 10, and the forming element is formed. Will be non-uniform. This problem becomes more remarkable especially as the substrate 10 becomes larger.

Therefore, according to the present invention, even when the rotary holder is used, the ion implantation distance in the specific direction of the substrate can be made uniform, and the elements formed in the substrate can be made uniform. The purpose is to provide an injection method.

[0008]

SUMMARY OF THE INVENTION The present invention is an ion implantation apparatus and an ion implantation method, which have been made to achieve the above object. That is, the ion implantation apparatus of the present invention is
This is a device that mounts a substrate on the periphery of the rotating holder and drives the ion beam onto the substrate at a specified incident angle while rotating the rotating holder about its center. Position detection to detect the rotating position of the rotating holder. Means, a deflecting means for applying a predetermined electric field to the ion beam to be implanted into the substrate, and a predetermined signal to the deflecting means based on the rotational position of the rotary holder detected by the position detecting means for the substrate of the ion beam to be implanted into the substrate. And a control means for controlling the incident angle.

Further, according to the ion implantation method of the present invention, when the substrate is mounted on the peripheral portion of the rotary holder and the ion beam is implanted, the rotary position of the rotary holder is detected, and based on the detected rotary position. This is a method of controlling the incident angle of the ion beam that is implanted into the substrate.

[0010]

In the ion implantation apparatus of the present invention, the position detecting means detects the rotational position of the rotary holder, and a signal based on the detected rotational position is given from the control means to the deflecting means. That is, the control means calculates which position of the substrate is irradiated with the ion beam from the rotational position of the rotary holder provided by the position detection means, and the case where the central part of the substrate is irradiated with the ion beam, The signal applied to the deflection means, that is, the applied voltage applied to the ion beam is controlled so as to change the incident angle of the ion beam with respect to the substrate depending on whether the peripheral portion of the substrate is irradiated with the ion beam. As a result, the implantation distance of the ion beam in the specific direction of the substrate can be made constant between the central portion and the peripheral portion of the substrate.

Further, in the ion implantation method of the present invention, when the ion beam is implanted, the rotational position of the rotary holder is detected, and the incident angle of the ion beam to be implanted into the substrate is controlled based on the detected rotational position. are doing. That is, the irradiation position of the ion beam that moves with the rotation of the substrate is calculated, and the implantation distance for the specific direction of the substrate in the ion beam at the central portion of the substrate and the specific direction of the substrate for the ion beam in the peripheral portion of the substrate are measured. The incident angle of the ion beam is controlled so that the implantation distance is constant.

[0012]

Embodiments of the ion implantation apparatus and ion implantation method of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram illustrating an ion implantation apparatus of the present invention,
(A) is a top view and (b) is a front view. That is, in the ion implantation apparatus 1 according to the present embodiment, for example, a plurality of substrates 10 for performing ion implantation are mounted on the peripheral portion of the rotation holder 2, and the rotation holder 2 is rotated about its center O as an ion beam. Is a device for driving at a predetermined incident angle.

The ion implantation apparatus 1 mainly includes a rotary holder 2 for mounting the substrate 10, a position detector 3 for detecting a rotational position of the rotary holder 2, and a substrate 10.
A deflection unit 4 that applies a predetermined electric field to the ion beam that is bombarded with a beam, and a control circuit 5 that controls a signal that is applied to the deflection unit 4 based on the information on the rotational position of the rotary holder 2 obtained from the position detection unit 3 are provided. .

The position detector 3 comprises a plurality of holes 31 formed at equal intervals in the peripheral portion of the rotary holder 2 and, for example, an optical sensor 32 for detecting the positions of these holes 31. Has been done. The plurality of holes 31 are, for example, the holes 3 of A located between the substrates 10 to be mounted.
1 and B holes 31 located beside each substrate 10 are alternately arranged. The sensor 32 of the position detection unit 3 emits a predetermined light (not shown) in the direction of the rotary holder 2, and when the hole 31 moves to the position of the sensor 32 by the rotation of the rotary holder 2, the sensor 32 emits light. Hole 31
The light passing through is detected. The position detector 3 has this hole 3
The rotation position of the rotary holder 2 is calculated based on the presence / absence of light passing through 1, and information about the rotation position is transmitted to the control circuit 5.

In the control circuit 5, the rotational position of the rotary holder 2 detected by the position detector 3 and the substrate 10 for the ion beam.
And the voltage applied between the electrodes 41 and 42 of the deflection unit 4 is controlled based on the information on the rotational position of the rotary holder 2 obtained from the position detection unit 3. . FIG. 2 is a diagram showing the relationship between the rotational position and the applied voltage. That is, in this figure, the rotational position of the rotary holder 2 is the position of the hole 31 detected by the position detector 3 (A, B).
The electrodes 41 of the deflection unit 4 corresponding to
The applied voltage across 42 is shown.

That is, in the control circuit 5, the voltage applied between the electrodes 41 and 42 is maximized when the hole 31 of A is detected in the position detecting section 3, and the electrodes 41 and 42 are detected when the hole 31 of B is detected. The applied voltage is controlled so that the voltage applied to the space is minimized.

When the applied voltage applied between the electrodes 41 and 42 of the deflecting section 4 is large, the amount of change in the incident angle of the ion beam with respect to the substrate 10 is large, while when the applied voltage is small, the substrate is small. The amount of change in the incident angle of the ion beam with respect to 10 becomes small. As described above, the ion beam has an incident angle of approximately 5 ° to 7 ° with respect to the substrate 10 in advance to prevent channeling, and an applied voltage applied between the electrodes 41 and 42 of the deflection unit 4 is applied. When the voltage is "0", there is no change in the incident angle of the ion beam, that is, the implantation is performed on the substrate 10 with the incident angle set in advance.

By electrically controlling the incident angle of the ion beam as described above, the lateral component of the ion beam in the central portion of the substrate 10 and the lateral component of the beam in the peripheral portion can be equalized. Becomes That is, the distance of the impurity region formed in the central portion of the substrate 10 in the horizontal direction of the substrate 10 and the distance of the impurity region formed in the peripheral portion of the substrate 10 in the horizontal direction of the substrate 10 can be equalized. become.

Next, the ion implantation method of the present invention will be described. The ion implantation method of the present invention detects the rotational position of the rotary holder 2 shown in FIG. 1 when implanting an ion beam, and controls the incident angle of the ion beam to be implanted into the substrate 10 based on the detected rotational position. There is a feature in doing it.

In this embodiment, the position detector 3 of the ion implanter 1 shown in FIG. 1 detects the rotational position of the rotary holder 2, and the control circuit 5 causes the deflection unit 4 to detect the rotational position based on this rotational position.
The incident angle of the ion beam is controlled by controlling the voltage applied between the electrodes 41 and 42 of the.

That is, in the step of detecting the hole 31 of B in the position detecting section 3, that is, the step of irradiating the central portion of the substrate 10 with the ion beam, the change amount of the incident angle of the ion beam is set to "0" to prevent the channeling. For this purpose, ion implantation is performed at an incident angle preliminarily attached. Further, the applied voltage gradually increases at the stage of detecting the hole 31 of A from the hole 31 of B by the position detection unit 3, that is, at the stage where the irradiation position of the ion beam moves from the central portion to the peripheral portion of the substrate 10,
Ion implantation is performed at an incident angle larger than the incident angle set in advance.

When the control of the applied voltage between the electrodes 41 and 42 is performed based on the relationship between the rotational position and the applied voltage shown in FIG. 2, the locus of the ion beam is a broken line α shown in FIG.
As shown in FIG.
In order to make the trajectory of the ion beam an accurate straight line, the applied voltage shown in FIG. 2 is changed in a trigonometric function (sine curve or cosine curve) with respect to the rotational position.

By changing the angle of incidence of the ion beam with respect to the irradiation position on the substrate 10 in this way, the implantation distance of the ion beam in the lateral direction of the ion beam at the central portion of the substrate 10 and the periphery of the substrate 10 are increased. It is possible to make the implantation distance in the lateral direction of the substrate 10 in the ion beam in a portion substantially constant. That is, the substrate 10
The distribution of the impurity regions formed in the central portion and the peripheral portion of the substrate 10 in the lateral direction of the substrate 10 becomes substantially equal,
It is possible to make the characteristics of the plurality of elements formed therein uniform.

Although the position detecting section 3 shown in this embodiment is composed of the hole 31 and the sensor 32, the present invention is not limited to this, and for example, mechanical or electrical based on the angle of the rotary holder 2. Alternatively, the rotational position may be detected automatically.

[0025]

As described above, the ion implantation apparatus and the ion implantation method of the present invention have the following effects. That is, according to the ion implantation apparatus of the present invention, the rotational position of the rotary holder is detected by the position detecting means, and the control means gives a predetermined signal to the deflecting means based on the detected rotational position to make the incident angle of the ion beam. Since it is controlled, it is possible to make the implantation distance between the central portion and the peripheral portion of the substrate constant in a specific direction with a simple configuration only by electrical control. Further, according to the ion implantation method of the present invention, since the incident angle of the ion beam is controlled based on the rotation position of the rotary holder, even when the rotary holder is used, the ion beam is implanted in a specific direction in the substrate. The distance can be made constant, and the characteristics of the elements formed in the substrate can be made uniform.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating an ion implantation apparatus of the present invention,
(A) is a top view and (b) is a front view.

FIG. 2 is a diagram showing a relationship between a rotational position and an applied voltage.

FIG. 3 is a diagram illustrating a rotation holder.

FIG. 4 is a diagram illustrating a trajectory of an ion beam.

FIG. 5 is a diagram illustrating an impurity region.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ion implantation device 2 Rotation holder 3 Position detection part 4 Deflection part 5 Control circuit 10 Substrate 31 Hole 32 Sensor 41, 42 Electrode

Claims (2)

[Claims] 1. A substrate is mounted on the periphery of a rotary holder,
An ion implanter for implanting an ion beam onto a substrate at a predetermined incident angle while rotating the rotary holder about its center, the position detecting unit detecting a rotational position of the rotary holder; Deflection means for applying a predetermined electric field to the ion beam that is driven into, and a predetermined signal to the deflection means based on the rotational position of the rotary holder detected by the position detection means, and the incident angle of the ion beam that is driven into the substrate And a control means for controlling the ion implantation device. 2. A substrate is mounted on a peripheral portion of the rotary holder,
An ion implantation method of implanting an ion beam at a predetermined incident angle with respect to the substrate while rotating the rotary holder about its center, wherein the rotational position of the rotary holder is changed when implanting the ion beam. An ion implantation method characterized by detecting and controlling an incident angle of an ion beam to be implanted into the substrate based on the detected rotational position.