JPH04202778A - Ion implantation device - Google Patents

Abstract

PURPOSE:To increase the number of wafers implanted with an ion at one time without need for a large space by using plural disks for charging a wafer and superposing the disks on one another. CONSTITUTION:A positive ion formed in an arc chamber is drawn out by a drawing electrode and implanted in the surface of a wafer 9 charged on disks 81 and 82. One disk 81 is placed close to an ion source, and the other disk 82 is separated from the disk 81 by the distance 10. A hatched part 11 is irradiated with an ion beam, the disks 81 and 82 are rotated at high speed in direction of the arrow A and scanned in direction of the arrow B, and the ion is implanted in the wafers on the disks 81 and 82. Since the two disks are used, the wafers twice more than before are implanted with the ion at one time.

Description

[Detailed description of the invention] (Industrial application field) The present invention applies to P-type semiconductors in various semiconductor manufacturing processes.

The present invention relates to an ion implantation device for diffusing n-type impurities.

[Conventional technology]

FIG. 3 is a cross-sectional view of a conventional large current ion implanter.

In the figure, a gas containing an element to be implanted, such as ^sH3 gas, is fed into the arc chamber (1) which is an ion source. By passing a current through the filament (2) in this gas, the emitted thermionic electrons collide and the inside of the arc chamber (1) becomes a plasma state, resulting in "As" * As
++ No ions such as 8s23 are generated. The stiff ions are extracted from the beam ratio slit in the arc chamber (1) by applying a negative bias to the extraction electrode (3). This extracted ion beam contains duplicate isotopes such as As'' and As2'' as well as different types of ions, so the necessary 7 S A is selected from among them.
A mass spectrometer (4) is used to extract only S+.

This mass spectrometer (4) changes the magnetic field to
Selecting ion mass. In other words, 7 S A S
``Ions whose mass is heavier than the ions cannot bend through the mass spectrometer tube (4) and collide into the mass spectrometer tube (4), whereas ions whose mass is lighter tend to bend easily and similarly fall into the mass spectrometer tube (4). will collide with.

From the 7 S As extracted in this way, ions having a mass close to 75 As+ are further removed on the analysis slit (5) in the beam line, and the beam area is further limited on the shaping slit (6).

This ion beam is measured by Faraday (
As shown in FIG. 2, the disk (8) rotates at high speed in the direction shown in the figure and scans in the direction B in the figure, thereby implanting ions into the surfaces of the thirteen wafers (9).

[Problem to be solved by the invention]

Conventional high-current ion implanters are configured as described above, and ion implantation is performed by loading a wafer onto a single disk, which rotates at high speed and scans in a fixed direction.

If the diameter of the wafer becomes larger, the radius of the disk must be increased in order to implant the same number of wafers at once as in the past, and this structure has a problem in that there is a limit due to space constraints.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an ion implantation apparatus that can increase the number of wafers implanted at one time without taking up space.

[Means to solve the problem]

The ion implantation device according to the present invention increases the number of wafers that can be implanted at one time by increasing the number of wafer loading disks from one to a plurality and stacking each disk. It is.

[Effect]

By increasing the number of disks, the ion implantation device of the present invention can increase the number of sea urchins that can be ion-implanted at one time without increasing the disk radius or taking up space. As a result, throughput can be improved.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

5. Since the high current ion implantation apparatus of the present invention is the same as the conventional high current ion implantation apparatus except for the disk loaded with the wafer to be ion implanted, the structure of the disk will be explained.

Figure '41 is a front view of a disk that is an embodiment of the present invention. In the figure, (8) (82) is a disk,
(9) is a wafer.

In the high current ion implantation device of the present invention, positive ions such as 75As" generated in the arc chamber (1) are extracted by the extraction electrode as in the conventional case, and the mass spectrometer (4)
It passes through an analysis slit (6), a shaped slit Faraday cup (7) and is injected onto the surface of a wafer (9) loaded onto a disk (al) (82). As shown in FIG. 1, the disc of the present invention includes two discs (81).
In (82), the subsequent disk (82) is shifted from the disk (81) near the ion source by an interval (10) equal to or more than one wafer. If the ion beam is irradiated as shown in the shaded area (11), the two disks (81) and (82) rotate at high speed in the A direction and scan in the B direction. Ion implantation is performed on 26 wafers (9) on disks (81) and (82).

〔Effect of the invention〕

As described above, according to the present invention, by using a structure in which two discs are stacked, it is possible to inject twice as many sea urchins at once as the number of eight sea urchins that can be loaded onto one conventional disc. This has the effect of improving throughput.

[Brief explanation of the drawing]

FIG. 1 is a front view of a disk of a large current ion implanter which is an embodiment of the present invention, FIG. 2 is a front view of a disk of a conventional large current ion implanter, and FIG. 3 is a front view of a disk of a conventional large current ion implanter. FIG. 2 is a cross-sectional view of a high current ion implanter. In the figure, (8]) (82) (8) is a disk, (9) is a wafer, (10) is an interval between disks, and (11) is an ion beam. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] Positively ionizes the element, accelerates the ion electrostatically,
An ion implantation device that implants these accelerated positive ions into the target object loads the implanted object into a disk, and this disk rotates at high speed and performs the implantation by scanning motion. The disk next to this disk is always moved by at least the size of the object to be injected with respect to the disk near the center, so that the object on any disk can be irradiated with ion gas. Ion implanter.