JPH0457474B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wafer holder for holding a semiconductor wafer.

The purity of semiconductor wafers is extremely carefully maintained during processes such as epitaxial growth so as not to impair their semiconductor properties. For this reason, high-purity products are used for all of the susceptor on which the wafer is placed, the furnace body for heat treatment, and the water for cleaning. Furthermore, between each process, wafer holders such as tweezers are used to pinch and transport the wafers, but to prevent contamination, the parts that come into contact with the wafers are covered with Teflon, quartz glass, etc.
Those protected with silicon carbide, metal silicon, etc. are used.

However, in any of the wafer holders, the contact portion is made on a flat surface of the wafer, and the area of the contact portion is large.

In addition, a wafer holder that is structured to stick to the back side of the wafer is sometimes used to prevent it from coming into contact with the epitaxial growth surface of the wafer, but even with such a wafer holder, it is difficult to pick it up from a susceptor, etc. It is easily contaminated and scratched.

Therefore, in the subsequent steps, there were many defects caused by contamination or scratches on the wafer due to the use of the wafer holder, resulting in poor yield.

The present invention has been made in order to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide a wafer holder that allows easy handling of wafers and does not have any adverse effect on the flat surfaces of both the front and back surfaces of the wafer. It is something.

To achieve this object, the present invention includes a plurality of holding arms whose tail ends are pivotally supported via a fulcrum around a vertically movable rod. The rod has a wafer holding part formed inward in a key shape so that the rod faces downward from the horizontal position, and the wafer holding part is configured to hold the wafer by making contact with the wafer at three or more places, and the rod The tail end of the actuating arm is pivotally supported via a fulcrum around a guide or cylinder provided coaxially so as to be movable relative to the actuating arm,
The at least one holding arm is pivoted to the distal end of the actuating arm via a fulcrum in the middle thereof, and a portion of the holding arm below the fulcrum pivoted to the distal end of the actuating arm is bent outward. The gist is a wafer holder that is characterized by:

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

First, the embodiment shown in FIG. 1 will be described. Reference numeral 1 indicates the lower part of the wafer holder. The three holding arms 3a, 3b, and 3c have wafer holding parts 9a, 9b, and 9c at their tips, respectively. The wafer holding parts 9a, 9b, and 9c contact only the peripheral edge of the wafer W, do not affect the flat surface of the wafer, and are formed inward in a hook shape so that the tips point downward from the horizontal direction. Only the peripheral edge of the wafer W is held at three locations. Wafer holding parts 9a, 9b, 9c
are bent and supported at the ends of the holding arms 3a, 3b, and 3c in a direction opposite to the direction of the inward hook-shaped portion at the tip of the wafer holding portion, that is, outward. Further, the wafer holding parts 9a, 9b, 9c may be constructed integrally with the main bodies of the holding arms 3a, 3b, 3c, or may be constructed separately, but in the illustrated example, they have an integral structure.

An operating arm 4 is connected in the middle of the holding arms 3a, 3b, 3c via fulcrums 5a, 5b, 5c, respectively.
One ends of a, 4b, and 4c are pivotally supported. The other ends of the operating arms 4a, 4b, 4c are attached to the guide 2 at a fulcrum 7.
a, 7b, (one of the three not shown).

The rod 8 passes through the guide 2 and is relatively movable. 3 at the lower end 8a of the rod 8.
The tail end of the book holding arms 3a, 3b, 3c is the fulcrum 6
a, 6b (one of the three is not shown). Although not shown, the upper end of the rod 8 is connected to a driving means such as an air cylinder.

The material of the wafer holder 1 is quartz glass, silicon carbide, silicon nitride, metallic silicon, etc. so as not to contaminate the wafer W, prevent it from being attacked by cleaning liquid, and be mechanically and chemically stable at high temperatures.
Quartz glass coated with high-purity and dense silicon nitride, silica glass coated with Teflon, metal high-purity alumina porcelain coated with Teflon (e.g. products made by Toshiba Ceramics)
TPA) etc. are preferable, but since they are expensive, the wafer holding part 9 that comes into contact with the wafer W and cleaning solution
Only (a, b, c) may be made of such a material.

The guide 2 is fixed, and the rod 8 is moved along the guide 2 in the vertical direction in the figure. 10 indicates a return spring.

When the rod 8 is slid in the direction of arrow A or B along the guide 2 by a driving means such as an air cylinder, the three holding arms 3 (a, b and c) open and close at the same degree as shown in Figure 2.

When pinching wafer W, move rod 8 to arrow B
Slide the holding arm 3 (a, b, c) in the direction of
is opened larger than the diameter of the wafer W. Next, the rod 8 is gradually slid in the direction of the arrow A, and the wafer holding part 9 (a, b, c) is brought into contact with the peripheral edge of the wafer W while the holding arm 3 (a, b, c) is collapsed. Then, as shown in FIG. 3, hold the wafer W in a fixed position (not shown) by holding the wafer W with the key-shaped parts of the wafer holder 9 (a, b, c) so as not to touch the upper and lower flat parts of the wafer. move it.

FIG. 4 shows another embodiment. In this embodiment, the rod 8 is fixed, and the guide 2 can move vertically along the rod 8. Although not shown, the guide 2 is adapted to be moved by a driving means such as an air cylinder.

Further, to explain one of the three arms as an example, a wafer holding part 9 is fixed to the tip of the holding arm 3 by a connecting member 11. As is clear from the figure, this wafer holding section 9 itself has a curved structure, and substantially the holding arm 3
The lower portion of the actuating arm 4 is bent outward from a fulcrum pivotally supported at the tip thereof.

As shown in FIG. 5, the wafer holding section 9 has a key-shaped tip for holding the wafer W.

In the drawings, the explanation has been given of a device having three holding arms, but the number of arms may be two or four or more. The case of three is preferable because it can be stably held by supporting at three locations. Furthermore, by dividing the wafer holding portion of the holding arm into two, for example, even with two holding arms, the wafer can be supported at three or four locations. Note that in the present invention, all of the holding arms do not necessarily have to be pivotally supported by the shaft; for example, one of the three holding arms
A book fixed to a rod can also hold a wafer in the same way. Also, guide 2
It is also possible to use the rod 8 as a cylinder and the rod 8 as a piston rod.

As described above, the wafer holder of the present invention has a structure in which the peripheral edge of the wafer is held in contact with at least three points, so that the wafer is less likely to be contaminated and its surface is less likely to be scratched. Furthermore, the wafer is stable during movement and will not fall. In particular, if the wafer holding portion of the holding arm is configured in a hook shape, the contact portion with the wafer will make minute contact with the corner of the wafer end face or the corner of the chamfered portion, and the influence on the wafer will be extremely reduced.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view showing an example of a wafer holder according to the present invention, FIG. 2 is an explanatory view showing the movement of the holding arm of the wafer holder shown in FIG. 1, and FIG.
Figure A is a diagram showing the state of contact between the wafer holding part of the holding arm of the wafer holder shown in Figure 1 and the wafer, Figure 3B is a sectional view taken along line BB in Figure 3A, 3C is a sectional view taken along line C-C in FIG. 3A, FIG. 4 is a partial sectional view showing another example of the wafer holder according to the present invention, and FIG. 5 is a sectional view of the wafer shown in FIG. 4. FIG. 6 is a diagram showing a contact relationship between a wafer holding part of a holding arm of a holder and a wafer. 1... Wafer holder, 2... Guide, 3...
Holding arm, 4... Operating arm, 5... Fulcrum, 6
... fulcrum, 7... fulcrum, 8... rod, 9... wafer holding section.

Claims (1)

[Claims] 1. A plurality of holding arms are provided around a vertically movable rod, the tail end of which is pivotally supported via a fulcrum, and the holding arm has an inner end so that the tip is directed downward from the horizontal position when the wafer is being held. The guide has a wafer holding part formed in a key shape in the direction of the rod, and is configured to hold the wafer by bringing the wafer holding part into contact with the wafer at three or more places, and is provided coaxially with the rod so as to be movable relative to the rod. Alternatively, the tail end of the actuating arm is pivotally supported around the cylinder via a fulcrum, and at least one of the holding arms is pivoted to the tip of the actuating arm via the fulcrum in the middle thereof, and the holding arm is A wafer holder characterized in that a portion below a fulcrum pivotally supported at the tip of an operating arm is bent outward.