JPH0449815Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a jig for semiconductor manufacturing, and more particularly to a jig for holding a semiconductor wafer in an ion implantation apparatus that implants impurity ions into a semiconductor wafer.

Conventional technology Diffusion of impurities such as phosphorus and boron into semiconductor wafers is usually carried out using a gas diffusion method, but this gas diffusion method requires heat treatment at high temperatures, resulting in problems with workability, concentration distribution, and energy consumption. There are problems with this. Therefore, recently, the ion implantation method as an impurity diffusion method that does not have the above-mentioned problems has been attracting attention and being widely used. This ion implantation method is a method in which impurity ions are bombarded and implanted into a semiconductor wafer.This ion implantation method includes a medium current method in which a medium current ion beam is deflected and scanned at a fixed angle over the semiconductor wafer. There is a high current method in which a high current ion beam is irradiated onto a semiconductor wafer that moves along a plane that is at a fixed angle with the ion beam.

The former medium current type ion implantation equipment described above implants ions into semiconductor wafers one by one, while the latter high current type ion implantation equipment uses a wafer holder (jig) on one disk.
A plurality of semiconductor wafers are arranged around the periphery of the semiconductor wafer, and while the wafer holder is rotated and moved up and down, the plurality of semiconductor wafers are sequentially irradiated with an ion beam from a fixed direction, so that ions are implanted into all the semiconductor wafers. When completed, a plurality of semiconductor wafers are removed together with the wafer holder.This high current type ion implantation apparatus will be explained with reference to FIGS. 6 to 8 as follows.

FIG. 6 is a schematic plan view of a high current type ion implantation apparatus, and FIG. 7 is a side view of a part thereof. In the figure, 1 is a semiconductor wafer, and 2 is a semiconductor wafer 1.
A disk-shaped wafer holder 3 is held at a predetermined interval around the front surface, and 3 is a vacuum chamber of the ion implantation apparatus, with an ion beam generation system 4 in one end and a wafer holder 2 held approximately vertically in the other end. A drive system 5 is disposed that supports the wafer holder 2 in a detachable manner, and also supports the wafer holder 2 in a manner that allows it to rotate around its center line and drive it up and down. Reference numeral 6 denotes a chamber connected to the end of the vacuum chamber 3 where the drive system 5 is located, and the interior has a volume that accommodates two wafer holders 2, 2. Semiconductor wafers 1, 1... are loaded, and semiconductor wafers 1, 1... are loaded before ion implantation into the drive system 5.
The wafer holder 2 having the ion-implanted semiconductor wafer 1 is supplied from the drive system 5, and the ion-implanted semiconductor wafers 1, 1, . . . are unloaded from the wafer holder 2. . The loading and unloading operations of the semiconductor wafers 1, 1, . . . onto the wafer holder 2 are performed alternately at two locations within the chamber 6.

In the ion beam generation system 4, 7 is an ion source that generates ions containing target ions, 8 is an extraction electrode that extracts an ion beam 9' from the ion source 7, and 10 is an ion beam 9' extracted by the extraction electrode 8. an ion separator that applies a magnetic field to separate target ions and unnecessary ions; 11 is a slit through which the ion beam 9 containing only the target ions separated by the ion separator 10 passes; 12 is a slit 1;
1 is an acceleration system that accelerates the ion beam 9 that has passed through the ion beam 9, and 13 is a convergence system that focuses the accelerated ion beam 9 toward the semiconductor wafer 1 held by the wafer holder 2 in front.

Next, the ion implantation operation by the above-mentioned ion implantation apparatus will be explained. A predetermined number of non-ion-implanted semiconductor wafers 1, 1, . . . are attached to one wafer holder 2 inside and outside the chamber 6. For example, as shown in the front view of the wafer holder in FIG.
4, 14, and a pair of clampers 15, 15 which sandwich the semiconductor wafer 1 positioned by the pins 14, 14, . . . are provided at equal intervals. Next, a predetermined number of semiconductor wafers 1, 1...
A wafer holder 2 having a wafer holder 2 is automatically supplied to a drive system 5 in a vacuum chamber 3, and is set substantially perpendicularly to a substantially horizontal rotating shaft 5' of the drive system 5 that moves up and down. Then, the wafer holder 2 is rotated and lowered (or raised) by the drive system 5, and the ion beam 9 is emitted from the ion beam generation system 4 in a fixed direction. This ion beam 9 is incident on the semiconductor wafer 1 at, for example, the uppermost position of the wafer holder 2 at a constant angle (approximately 7 degrees). Therefore, as the wafer holder 2 rotates and descends (or ascends), the ion beam 9 Each semiconductor wafer 1, 1, . . . is sequentially irradiated with ion implantation, and the semiconductor wafers 1, 1, . In other words, if one semiconductor wafer 1 is continuously scanned with a large current ion beam 9, the semiconductor wafer 1 will become abnormally high temperature and become a defective product. By irradiating the semiconductor wafer 1 with a high-current ion beam 9 several times at intervals, the wafer holder 2 Dissipate heat to
Abnormal temperature rise is prevented. To improve this effect, the wafer holder 2 is provided with special cooling means (not shown).

When all the semiconductor wafers 1, 1, . Then, the unprocessed wafer holder 2 prepared at another position in the chamber 6 is supplied to the drive system 5, and ion implantation is performed in the same manner as described above. The wafer holder 2 having the ion-implanted semiconductor wafers 1, 1, . . . in the chamber 6 is removed from the chamber 6 at an appropriate time.
The ion-implanted semiconductor wafers 1, 1, . . . are removed manually, and the wafer holder 2 is reused.

Problems to be Solved by the Invention The loading and unloading of the wafer holder 2 into and out of the chamber 6 is performed in a continuous operation by opening the door of the chamber 6. The unloading work is performed alternately at two locations inside the chamber 6, so when the door of the chamber 6 is opened, there are two wafer holders 2 inside the chamber 6, and which one is before the ion implantation process and which one is after the ion implantation process. Sometimes I don't know what it is. That is, when the semiconductor wafer 1 is ion-implanted, the color of its surface changes slightly, and this color change can be visually judged to determine which of the two wafer holders 2 in the chamber 6 has been processed. It is very difficult to accurately determine whether there is. Therefore, the unprocessed wafer holder 2 in the chamber 6 is taken out, the processed wafer holder 2 is left behind, and the processed wafer holder 2 is sent to the vacuum chamber 3 again, where the semiconductor wafers 1, 1, . . . There was a work error in which ions were implanted twice, and contrary to the above, unprocessed wafer holder 2 in chamber 6 was mistakenly taken out as a processed wafer holder, and semiconductor wafers 1, 1, etc. were ion-implanted. Occasionally, errors occur that are sent to subsequent processes without being corrected, resulting in poor yields in semiconductor manufacturing.

Therefore, the purpose of this invention is to eliminate the above-mentioned work mistakes.
The goal is to prevent this from happening even with simple additional measures.

Means to Solve the Problems This invention displays temperature changes in the jig before and after ion implantation of the semiconductor wafer at a predetermined portion of the jig that holds the semiconductor wafer undergoing ion beam implantation. The above object is achieved by adding an ion-implanted indicator whose state changes.

Effect When ion implantation is performed on the semiconductor wafer attached to the jig while the ion implantation completion display means attached to the jig is set to the display state before ion implantation,
During this ion implantation, the display state of the ion implantation display means changes, so if you visually check the display state of the ion implantation completion display means, you can see at a glance whether the jig is before or after ion implantation processing. It's easy to understand.

Embodiment An embodiment of the present invention applied to, for example, a wafer holder (jig) in the above-mentioned high-current ion implantation apparatus will be described with reference to FIGS. 1 to 5.

The difference between the wafer holder 16 shown in FIGS. 1 to 5 from the conventional wafer holder 16 is that a plurality of clampers 15 on the front side of the wafer holder 16,
The only difference is that a shape memory alloy 17 as an example of an ion-implanted display means is attached to the selected ones of 15.... Although two shape memory alloys 17 are attached to the two clampers 15, 15 in FIG. 1, the number may be one, or three or more. Moreover, one shape memory alloy 17 is attached so as to be deformable as follows.

Now, a pair of clampers 15, 1 holding one semiconductor wafer 1 on the front side of the wafer holder 16 are installed.
5 opens and closes between the positions shown by the solid line and the chain line in FIG. 1 is taken out and supplied, the shape memory alloy 1
7 stores the shape of a straight line, for example, and one end of the shape memory alloy 17 on this straight line is a clamper 15.
It is fixed to the opening/closing support shaft 18 of the clamper 15 and extends along the outer surface of the clamper 15 when the clamper 15 is closed.
When opened, the opening force causes the shape memory alloy 17
is attached so that the end fixed to the support shaft 18 moves and deforms together with the clamper 1, as shown by the chain line in FIG. Furthermore, shape memory alloy 1
The operating temperature for returning the wafer holder 7 to the memorized shape is set during the temperature change before and after the ion implantation process of the wafer holder 16.

A plurality of non-ion-implanted semiconductor wafers 1, 1, . When ion implantation is performed, the shape memory alloy 17 is deformed as shown in FIGS. 4 and 5. That is, FIG. 4 shows the state before ion implantation, and at this time the shape memory alloy 17 is deformed into an F-shape even by the opening operation of the clamper 15. When ion implantation is performed in this state, the wafer holder 16 is heated by irradiation with the ion beam 9, and the shape memory alloy 17 is also heated, and when the shape memory alloy 17 is heated to the operating temperature of its shape displacement point, the shape memory alloy 17 As shown in Figure 5, it returns to its original straight shape.

Therefore, there are two wafer holders 1 in the chamber 6.
6 and 16, and when determining which of the two is before processing or after processing, it can be easily and accurately determined by looking at the shape of shape memory alloy 17 in wafer holder 16. Moreover, by opening the clamper 15, the shape memory alloy 17 is deformed into a shape different from the memorized shape, so that it is possible to avoid forgetting the manual work to deform the shape memory alloy 17 before the ion implantation process.

Note that the mounting position of the shape memory alloy 17 on the wafer holder 16 is not limited to the side surface of the clamper 15.
It may be mounted near the clamper 15 at a position where it deforms when the clamper 15 is opened, or at a position unrelated to the clamper 15 so that it deforms in a direction perpendicular to the front surface of the wafer holder 16.

Furthermore, instead of indicating that ions have been implanted by the change in shape of the shape memory alloy 17 itself, the indication may be made by displacing other members in accordance with the change in shape of the shape memory alloy 17.

Alternatively, instead of a shape memory alloy, a combination of bimetal and a mechanism that memorizes and retains its thermal deformation may be used.

Furthermore, other means can also be employed.

Effects of the invention According to the invention, the shape of the shape memory alloy attached to the jig determines whether the jig supporting the semiconductor wafer to be ion-implanted is before or after the ion implantation process. The display status of the ion-implanted display means can be accurately and easily determined by visually checking the display status of the ion-implanted display means, such as the ion-implanted display means. As a result, the yield of semiconductor manufacturing can be improved. In addition, it is easy to carry out because it is only necessary to add ion-implanted means such as shape memory alloy to a part of the jig of conventional equipment.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an embodiment of the semiconductor manufacturing jig according to the present invention, Fig. 2 is an enlarged view of a part of Fig. 1, and Fig. 3 is taken along line A-A in Fig. 2. 4 and 5 are cross-sectional views of the portion shown in FIG. 3 before and after ion implantation. FIG. 6 is a schematic plan view of a semiconductor manufacturing device (ion implantation device) using a conventional jig, FIG. 7 is a partial side view of the device shown in FIG. 6, and FIG. It is an enlarged front view of a tool. 1... Semiconductor wafer, 9... Ion beam,
16... jig (wafer holder), 17... ion implanted display means (shape memory alloy).

Claims (1)

[Scope of utility model registration request] A feature is that an ion implanted display means is attached to a predetermined part of a jig that holds a semiconductor wafer to be implanted with an ion beam, and the display state changes depending on the temperature change of the jig before and after ion implantation of the semiconductor wafer. Jig for semiconductor manufacturing.