JPH0678584B2 - Contamination prevention wafer rotating tool - Google Patents

Description

TECHNICAL FIELD The present invention relates to the field of semiconductor manufacturing, and more particularly to a wafer rotator for irradiating a wafer with a specific ion beam.

[Conventional technology]

When the wafer is doped with impurities by the ion implantation method, the wafer W is rotated as shown in FIG.
The cells are arranged in a circle on the top and are irradiated with an ion beam while being rotated by a rotating device. In this case, when the ion beam hits the rotating tool material near the wafer W, the element of the material undergoes sputtering and scatters to contaminate the wafer. Therefore, as shown in FIG. 7 which is a sectional view taken along the line CC of FIG. 6, the wafer rotator of the conventional ion implantation apparatus prevents the wafer rotator material from being sputtered by the ion beam (contamination to the wafer). In order to achieve the above), the structure is such that the position where the wafer is installed is raised, or the part where the ion beam of the wafer rotator hits is coated with a film containing a wafer element as a main component (for example, a In this case, it was a Si, SiN, or SiC film).

[Problems to be Solved by the Invention]

In the above-mentioned conventional example, the structure in which the wafer installation position of the wafer rotator is raised makes the processing complicated, and the contamination of the wafer rotator material cannot be completely prevented.
Further, there is a problem that the coating process becomes large in a structure in which a portion of the wafer rotating tool which is exposed to the ion beam is coated with a film containing a wafer element as a main component. Further, for example, in a device that mainly implants boron (B) into a silicon wafer, when phosphorus (P) is implanted, the dopant that was previously implanted enters the silicon wafer as contamination by the dopant that is subsequently implanted. There is a problem that it will end up. Conventionally, in such a case, the wafer rotator itself had to be replaced.

The present invention has been made to solve such a contamination problem.

[Means for Solving the Problems]

That is, according to the present invention, in order to solve the above-mentioned problems, the means constituting the contamination preventing wafer rotating tool has a plate for mounting a plurality of wafers or a hole for fitting a plurality of wafers on the rotatable disk. It is characterized in that the plate which is provided and has the same constituent element as that of the wafer as the main component is detachably installed by a fixture.

[Work]

When the contamination prevention wafer rotator is used as the above means, even if the plate component is sputtered by the ion beam, it does not contaminate the wafer. Further, if each wafer is detachably fixed with a fixing tool, it is possible to simply perform plate replacement without ion exchange when implanting different kinds of ions, which simplifies the work.

〔Example〕

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

FIG. 1 is a plan view of a contamination prevention wafer rotating tool according to the present invention. In this figure, reference numeral 1 denotes a disk which is rotated by a rotary drive device (not shown). A wafer 2 is arranged on the disk 1. A plate 3 is made of a material that does not pose a problem even if the wafer 2 is contaminated with an element that is sputtered out when the ion beam is irradiated and jumps out. For example, when the wafer 2 is a silicon wafer, a plate (SiC, SiN, etc.) containing silicon or a group IV element as a main component is used. In addition, a material other than a silicon wafer is selected so that the element that jumps into the wafer by sputtering does not pose a problem. For example, when the wafer is germanium, germanium or a plate containing germanium as a main component is selected, and when the wafer 2 is gallium arsenide, gallium arsenide or a plate containing this as a main component is selected.

2 is a partial plan view of FIG. 1, and FIG. 3 is AA of FIG.
FIG.

The plate 3 is provided with a hole 3a, and the size of the hole 3a matches the size of the wafer 2. Further, the plate 3 has a divided shape so that a large number can be spread on the disk 1, and its corners are detachably fixed by a fixing tool such as a screw 4. When the plate 3 is divided as described above, it is convenient because it can be replaced with a plate 3 that does not cause contamination when implanting different kinds of ions into the wafer 2. For example, when a large amount of boron (B) is implanted in a silicon wafer, the next phosphorus (P) is implanted in this state, the boron is sputtered and becomes a pollution source, and is contaminated. If this is done, such a situation can be prevented. When a large number of wafers 2 are simultaneously implanted with the same type of ions, a circular plate 3 may be formed and holes 3a matching the wafer size may be formed.

When the contamination prevention wafer rotating tool according to the present invention is configured as described above, the wafer is not contaminated even if the elements of the plate are sputtered by the ion beam. Further, if each wafer is detachably fixed with a screw, the plate exchange becomes extremely easy when implanting different kinds of ions.

The contamination prevention wafer rotator according to the present invention is as described above. However, as a modification, the same applies even if an Al plate or other metal plate is attached with a coating plate having the same element as the main component of the wafer of about 1 μm. Results are obtained. This is because the elements to be sputtered are limited to the vicinity of the surface. Further, the shape of the plate may be ring-shaped as shown in FIG. 4, or may be a shape that is spread below the wafer 2 as shown in the sectional view of FIG.

〔The invention's effect〕

Since the contamination-preventing wafer rotator according to the present invention is configured as described above in detail, the contamination-preventing wafer rotator can have a simpler structure than the conventional one and does not require a large-scale coating process. Further, even if a large amount of ions are implanted, contamination can be prevented if the plate is replaced. Furthermore, the contamination prevention measures can be taken by changing the plate material depending on the case of each of the Si semiconductor and the III-V group compound semiconductor.

[Brief description of drawings]

FIG. 1 is a plan view of a contamination preventing wafer rotating tool according to the present invention, FIG. 2 is a partial plan view of FIG. 1, and FIG. 3 is an A of FIG.
-A sectional view taken along arrow A, Fig. 4 (a) is a partial plan view when a wafer is fitted to a ring-shaped plate according to the present invention, and Fig. 4 (b) is viewed along arrow BB in (a). FIG. 5 is a sectional view of a modified embodiment in which the plate according to the present invention is spread below the wafer, and FIG. 6 is a partial plan view of a conventional contamination preventing wafer rotating tool. Is C in FIG.
FIG. 6 is a cross-sectional view taken along the arrow C. 1 ... disk, 2 ... wafer, 3 ... plate 3a ... hole, 4 ... screw

Claims (1)

[Claims] 1. A plate on which a plurality of wafers are placed or a hole in which a plurality of wafers are fitted is formed on a rotatable disk, and the component element of the same material as the wafer is the main component. A contamination-preventing wafer rotator in which a plate is detachably installed by a fixture.