JPH06223769A - Ion implantation device - Google Patents

Abstract

PURPOSE:To reduce metallic contamination as well as to realize the neutralization of a substrate with high accuracy by providing a substrate fixing disc or a shield plate interlocked with an arm or a beam mask, and thereby preventing parts other than the substrate from being irradiated by ion beams. CONSTITUTION:When ion beams 12 are implanted into a substrate 11, ions are implanted to the substrate 11 while the substrate is being scanned with respect to the ion beams 12 with a disc 21 or an arm 23 rotated by a rotating shaft 10, and concurrently with the disc or the arm translated by a column 14. In this case, since a shield plate 15 is fixed onto the column 14, the disc 21 or the arm 23 are not irradiated by the ion beams 12. This constitution thereby prevents the substrate from being contaminated by metals due to sputtering by the disc 21 or the arm 23 or from being charged by secondary electrons. A plate made of non-metallic material such as graphite and the like is desirable as the shield plate 15.

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 used in a semiconductor device manufacturing process.

[0002]

2. Description of the Related Art As shown in FIGS. 4A and 4B, a conventional ion implantation apparatus is used to form a disk 21 made of metal such as Al (see FIG.
a) or an arm 23 extending radially from the circumferential axis 22 (see FIG. 4).
While fixing the substrate 11 on the circumference of b) or the like and rotating the disk 21 or the arm 23 or the like at about 300 to 1600 rotations per minute, the disk 21 or the arm 23 or the like is about 1 to 20 cm per second. By exposing the substrate 11 to the ion beam 12 while performing a translational movement by
Impurity ions are uniformly implanted into the entire surface of the substrate 11. Further, in order to prevent the substrate 11 from being charged by the ion beam 12 having a positive charge, electrons having a negative charge are transferred to the substrate 11.
It is equipped with a mechanism for irradiating the substrate with the aim of electrically neutralizing the substrate.

[0003]

Conventionally, since the disk for fixing the substrate or the arm moves in translation, as shown in FIG. 3, the disk and the arm other than the substrate are exposed to the ion beam. Therefore, metal atoms such as Al that compose the disk or arm scatter due to a sprinkling phenomenon that pops out due to the impact of ion irradiation, and contaminates the substrate, or secondary particles generated from the disk or arm or the like. There is a problem that the electrons negatively charge the substrate, making it difficult to keep the substrate electrically neutralized.

Therefore, according to the present invention, it is possible to keep the electrical neutrality of the substrate clean and highly accurately by suppressing the metal contamination from the disc for fixing the substrate, the arm, etc. and the generation of secondary electrons. It is an object to provide an ion implantation device.

[0005]

In order to solve the above-mentioned problems, the ion implantation apparatus of the present invention scans a substrate with respect to an ion beam by moving a substrate fixing tool which fixes the substrate, and ion In an ion implantation apparatus for implanting a substrate into a substrate, it is characterized in that it has means for shielding the ion beam in conjunction with the movement of the substrate fixture.

[0006]

In the ion implantation apparatus of the present invention constructed as described above, the means for shielding the ion beam in conjunction with the movement of the substrate fixture is provided so that the substrate fixture is irradiated with the ion beam. Since it is possible to prevent the metal contamination and secondary electrons generated from the substrate fixture, the substrate can be kept clean and highly electrically neutral.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a view for explaining an embodiment of a substrate fixture and an ion beam shielding means in an ion implantation apparatus according to the present invention.

In FIG. 1, a substrate 11 is circumferentially fixed to a substrate fixing disk 21 or arm 23, and the disk 21 or arm 23 is attached to a rotary shaft 10 provided with a rotating mechanism (not shown). The rotating shaft 10 is supported by a column 14, which translates the disk 21 or the entire arm 23. Further, a shield plate 15 for preventing the ion beam 12 from irradiating the disk 21 or the arm 23 is provided on the support column 14 from immediately above the peripheral portion of the substrate mounted on the disk 21 or the arm 23 from the disk 21 or the arm 23. Is attached so as to cover the region irradiated with the ion beam 12 by the translational movement of the. Further, a Faraday cup 17 for measuring the value of the ion beam current at the time of ion implantation is provided. This Faraday cup 17 is made of graphite.

In order to implant the ion beam 12 into the substrate by this apparatus, the disk 21 or the arm 2 is rotated by the rotating shaft 10.
Ions are injected into the substrate while scanning the substrate with respect to the ion beam 12 by rotating 3 and translating it by the pillar 14. At this time, since the shielding plate 15 is fixed to the column 14, the disk 21 or the arm 23
Is not irradiated with the ion beam 12. For this reason, it is possible to prevent the contamination of the metal generated by the sputtering phenomenon from the disk 21 or the arm 23 or the charging of the substrate by the secondary electrons. The shield plate 15 is preferably a non-metal plate such as graphite. This is because when graphite is used, most of the irradiated ion beam 12 is absorbed, so that the ions are not diffusely reflected right above the substrate 11, and since graphite is conductive, it can be grounded. This is because it is possible to prevent the shield plate 15 from being charged.

FIG. 2 is a view for explaining means for shielding an ion beam of another embodiment of the sputtering apparatus according to the present invention. In this embodiment, a beam mask 16 interlocked with the translational movement of the support 14 is provided at the exit of the accelerating tube 13 for accelerating the ion beam 12, and the beam mask 16 is moved along with the passage of the substrate 11 so that the beam other than the substrate 11 12 is not irradiated.

[0012]

As described above, according to the present invention, a shield plate or a beam mask is provided which moves in conjunction with the translational movement of the column, that is, the translational movement of the disk or arm which is the substrate fixing tool, and the ion is provided in addition to the substrate. Since the irradiation of the beam is prevented, the ion implantation can be performed while the substrate being ion-implanted is kept clean and highly accurately neutralized.

[Brief description of drawings]

FIG. 1 is a view for explaining a substrate fixture and an ion beam shielding means of an ion implantation apparatus according to an embodiment of the present invention.

FIG. 2 is a view for explaining a substrate fixing member and an ion beam shielding means of an ion implantation apparatus according to another embodiment of the present invention.

FIG. 3 is a view for explaining a substrate fixture of a conventional ion implantation device.

FIG. 4a is a diagram for explaining a substrate fixing disk, and FIG. 4b is a diagram for explaining a substrate fixing arm.

[Explanation of symbols]

10 ... Rotation axis, 11 ... Substrate, 12 ... Ion beam, 13 ...
Accelerator tube, 14 ... Prop, 1
5 ... Shielding plate, 16 ... Beam mask,
17 ... Faraday cup 21 ... Disc, 22 ... Circumferential axis, 23 ... Arm.

Claims (1)

[Claims] 1. An ion implanter for scanning a substrate with respect to an ion beam by moving a substrate fixing tool which fixes the substrate and implanting ions into the substrate. An ion implantation apparatus having means for shielding an ion beam.