JPS6396855A - Ion implanting device - Google Patents

Abstract

PURPOSE:To obtain large-current ion beams of high quality by installing an ion deflecting part, in which an ion beam orbit is deflected, between an ion separating part and an ion implanting chamber and installing a scanning part for mobile scanning in the ion implanting chamber. CONSTITUTION:Ions generated in an ion source 1 are accelerated in an ion accelerating part 2 and made to enter an ion separating part 4 and separated into ion species with specific mass by a magnetic field in the ion separating part 4. The ion species with specific mass are guided to an ion deflecting part 5 and an ion beam orbit 3 is bent by a magnetic field in the deflecting part 5. Next, the beams are guided to a prescribed position of the ion implanting chamber 9 and made to impinge on wafers 11 on a disk 6. When an ion implanting operation is not performed, the ion beams are deflected in the ion deflecting part 5 and made to move rectilinearly to a Faraday cup 10. The Faraday cup 10 is formed into an absorber which absorbs neutral particles of carbon or the like and needless ions. The disk 6 is rotated by a disk rotating motor 7 and scanned by a disk scanning motor 8, and ion implantation is performed uniformly on the whole surface of the wafer 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ion implantation device for semiconductor manufacturing equipment that obtains a large current ion beam. This invention relates to an ion implantation device that removes or minimizes unnecessary substances such as neutral particles and denatured ions to obtain a high-quality, high-energy ion bee 11.

[Conventional technology]

As an ion implantation device that obtains a large current ion beam output, for example, a method as described in Japanese Patent Application Laid-Open No. 105153/1980 is known. In such a method,
In order to obtain a large current ion beam output, a strong magnetic field is used to separate specific ion species. Furthermore, there is a structural limit to increasing the strength of this magnetic field. For this reason, a method is known in which ions are separated using a strong magnetic field and then accelerated in a subsequent stage.

Furthermore, a mechanical scanning method is also known in which when scanning and implanting an ion beam into an irradiation object, the object itself is rotated and moved. As such a method, Japanese Patent Application Laid-open No. 5
There are publications such as No. 7-187853 and Japanese Unexamined Patent Publication No. 182956/1982.

[Problem that the invention seeks to solve]

The ion implantation apparatus of the present invention aims to obtain a high-current, high-quality ion beam.

However, when trying to extract high-energy ion species by applying a strong magnetic field and, in particular, by having an accelerating section after the magnet for separating ion species, the effect of the strong magnetic field and the addition of energy to the separated ions make it difficult to extract high-energy ion species. Unnecessary substances such as sexual particles and denatured ions are generated, which adversely affects the irradiated object.

Furthermore, it has been found that when a scanning magnetic field is applied to scan the separated ion beam over the irradiated object, this magnetic field also generates unnecessary substances and has an adverse effect.

Particularly in fine semiconductor devices, if unnecessary material is implanted onto the object to be irradiated, the accuracy of the object to be irradiated will be reduced, resulting in a fatal defect.

[Means for solving problems]

In the present invention, in order to obtain a high-quality, high-energy ion beam, a deflection section is provided to remove unnecessary substances after accelerating the separated ions, and a high-quality ion beam from which unnecessary substances have been removed generates unnecessary substances. By adopting a mechanical scanning method that mechanically moves and scans the irradiated object without using magnetic field scanning to avoid applying unnecessary magnetic fields, unnecessary substances that reach the irradiated object are thoroughly removed and their generation is suppressed. It was configured to do this.

[Effect]

The magnetic field of the ion deflection unit is created by applying the magnetic field strength necessary to deflect specific ions by a desired angle, so that positively charged ions with a specific mass are Neutral particles are deflected so that they enter a trajectory that leads them to a predetermined location in the implantation chamber, but since neutral particles are unaffected by the magnetic field and travel straight, unnecessary ions are Since the strength is different from the strength required to guide ions to a predetermined location in the ion implantation chamber, the force moves to deviate from the ion implantation trajectory. As a result, only ion beams with a specific mass are guided to the ion implantation position in the ion implantation chamber after passing through the deflection magnetic field, so that neutral particles and unnecessary ions are implanted into the ion target object. You won't get caught.

At the same time, since the high-quality ion beam from which unnecessary substances have been removed is then subjected to a mechanical scanning method without the magnetic field generated by unnecessary substances, the irradiated object is irradiated with a high-quality ion beam.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1, 2, and 3.

FIG. 1 shows an ion beam section of a pre-acceleration type ion implantation apparatus having an ion beam trajectory according to the present invention.

This is a three-dimensional diagram. FIG. 2 is a side view of the ion beam trajectory in FIG. 1.

Ions generated by the ion source 1 are accelerated by the ion accelerator 2, enter the ion separation part 4, and are separated into ion species having a specific mass by the magnetic field of the separation part. Ion species having a specific mass are guided to the ion deflection unit 5, and the ion beam trajectory is bent by the magnetic field of the ion deflection unit 5, and guided to a predetermined position in the ion implantation chamber 9, where it is guided to the wafer 11 of the disk 6. (Ions are implanted into the irradiated object).

When the ion deflection unit 5 does not perform an implantation operation, the ion beam does not deflect and the ion beam travels straight to the Faraday tube 10. The Faraday tube 10 is composed of an absorber for neutral particles such as carbon and unnecessary ions.

The disk 6 is rotated by a disk rotation motor 7 and scanned by a disk scanning motor 8, so that uniform ion implantation is performed over the entire surface of the wafer 11.

Neutral particles generated between the exit of the ion separation unit 4 and the ion deflection unit 5 are not deflected even by the magnetic field of the ion deflection unit 5,
Faraday hit 10 and never hit disk 6. Furthermore, since ions other than those having a specific mass deviate from the ion beam trajectory 3 that reaches a predetermined position in the ion implantation chamber 9, they are blocked by the slit 12 and the like, and are not implanted into the disk 6.

FIG. 3 is a side view of a post-acceleration type ion beam trajectory having an ion accelerating section 2 after the ion separation section 4 in the ion implantation apparatus having the ion beam trajectory of the present invention.

FIG. 4 shows a conventionally used ion beam trajectory, in which the ion beam exits the ion separation section 4.

〔Effect of the invention〕

According to the present invention, the ion beam trajectory is bent by the magnetic field of the ion deflection unit installed in front of the ion implantation chamber, and neutral particles and unnecessary ions can be removed. Since the magnetic field generated by ions is completely eliminated, ion implantation accuracy is extremely high, and
It is possible to prevent unnecessary ions and neutral particles from being implanted into the ion-irradiated object to the maximum extent possible.

[Brief explanation of the drawing]

Fig. 1 is a schematic three-dimensional diagram of the ion beam trajectory of the present invention; Fig. 2 is a side view of the ion beam trajectory (pre-stage acceleration method) of Fig. 1; Fig. 3 is a schematic three-dimensional diagram of the ion beam trajectory of the present invention; The figure shows a side view of the ion beam trajectory using the post-acceleration method. Fourth
The figure shows a three-dimensional view of an ion beam trajectory used in a conventional ion implantation device. DESCRIPTION OF SYMBOLS 1... Ion source, 2... Ion acceleration part, 3... Ion beam orbit, 4... Ion separation part, 5... Ion deflection part, 6... Disk, 7... Disk Rotating motor, 8... Disk scanning motor, 9... Ion implantation chamber, 10... Faraday tube, 11... Wafer, 12... Slit 12--Slit

Claims (1)

[Scope of Claims] 1. An ion source section that generates ions, an ion separation section that separates ions having a specific mass from the ions generated by the ion source and extracts them as an ion beam, and an ion beam receiving section. It consists of an ion implantation chamber where the irradiation object is installed.
In the ion implantation apparatus in which the trajectory of the ion beam is in one plane, an ion deflection section for deflecting the ion beam trajectory is provided between the ion separation section and the ion implantation chamber, and the ion chamber is moved and scanned. An ion implantation device characterized by being provided with a scanning section. 2. The ion implantation apparatus according to claim 1, wherein the ion beam trajectory provided with the ion deflection section is within one plane. 3. In claim 1, the ion implantation chamber is characterized by having a disk on which an object to be ion irradiated is mounted, and a disk that is rotated so as to move the disk across the ion beam trajectory. Ion implantation equipment. 4. Claim 1 states that when the ion deflection section does not deflect ions, the ions have a beam trajectory in which the ions proceed in a straight trajectory from the exit of the ion separation section and are guided to the ion beam amount measuring device. Features of ion implantation equipment.