JPS6319321Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a wafer holding mechanism of a vapor deposition machine.

Semiconductor devices such as transistors, diodes, thyristors, and integrated circuits are generally manufactured through a process in which a large number of elements are formed on a single semiconductor wafer by diffusion, etc., electrodes are formed, and the wafer is divided into a large number of pellets. ing. The electrodes may be formed by a plating method, but recently they are often formed by a vapor deposition method. This type of electrode is made of various metals depending on the type and product of the semiconductor device, and representative metals include Al, Au, Ag, Cr,
There are Ni etc.

The vapor deposition machine used for forming the electrodes described above has a structure schematically shown in FIG. In the figure, reference numeral 1 denotes a bell gear, and a hearth 3 containing a vapor-deposited metal 2 is disposed below the center of the bell gear, and an electron gun 4 is disposed below the hearth 3 in a horizontal direction. A plurality of planetariums 5 are arranged inside the bell gear 1. These planetariums 5 are configured to rotate and revolve by the following mechanism. That is, 6 is a motor, which rotates a driving gear 7, thereby rotating a passive gear 8 at an appropriate reduction ratio, and as the passive gear 8 rotates, the center of the bell gear is rotated via a shaft 9. By rotating the disc 11 at a predetermined speed about the shaft 10, the planetarium 5 attached to the disc 11 via the arm 12 is rotated around the central axis 1.
0 as the center of rotation, and each planetarium 5 rotatably attached to the arm 12 is caused to rotate around the axis 15 by means of the disk 13 and rail 14 fixed to the planetarium 5. It is. 16 is a shutter disposed between the hearth 3 and the planetarium 5; 17 is an exhaust pipe for evacuating and exhausting the bell gear 1; and 18 is a water cooling pipe for cooling the bell gear 1.

As is clear from FIG. 2 and FIG. 3, which is an enlarged sectional view of the main part along the line - in FIG.
It has a plurality of through holes 19, and a stepped portion 20 is provided at the periphery of each through hole 19. A semiconductor wafer 21 is placed on this stepped portion 20 with the surface on which a deposited film is to be formed facing downward, and the upper surface of the semiconductor wafer 21 is pressed by a spring member 22 to allow the planetarium 5 to rotate and revolve. Therefore, semiconductor wafer 2
1 will not be removed from Planetarium 5. Here, the spring material 22 is used to directly hold the semiconductor wafer 2.
When the center of the top surface of 1 is pressed, the semiconductor wafer 2
Stress is concentrated in the center of the semiconductor wafer 21
Not only is it easy to break, but also the spring material 22 will damage the top surface of the semiconductor wafer 21, especially if an aluminum electrode or the like is formed on this top surface. Because it may get stuck and stick to the
As shown in FIG. 3, a dummy wafer 23 is interposed between the semiconductor wafer 21 and the spring material 22. However, even with this method, it was not possible to completely eliminate scratches on the upper surface of the semiconductor wafer 21, particularly on the minute aluminum electrodes of the integrated circuit, and cracks in the semiconductor wafer 21 also occurred.

Therefore, the main purpose of this invention is to prevent the electrodes on the top surface of the semiconductor wafer from being scratched as described above.
It is an object of the present invention to provide a wafer holding mechanism that does not damage semiconductor wafers.

Examples of this invention will be described below with reference to the drawings.

FIG. 4 shows an enlarged sectional view of a main part of the planetarium 5 corresponding to FIG. 3 of the first embodiment. In the figure, the same parts as in FIG. 3 are given the same reference numerals, and the explanation thereof will be omitted. The feature of this embodiment is that a dish-shaped member 24 made of stainless steel or the like is used in place of the dummy wafer 23, and only the peripheral part of the semiconductor wafer 21 above the step 20 is pressed by the flange part 25 on the peripheral edge of the dish-shaped member 24. It is.

According to the above configuration, only the peripheral portion of the semiconductor wafer 21 is pressed by the flange portion 25 of the dish-shaped member 24, and the dish-shaped member 24 is floating from the center of the upper surface of the semiconductor wafer 21.
Even if an aluminum electrode is formed on the top surface of the semiconductor wafer 21, this aluminum electrode will not be scratched, and the semiconductor wafer 21
Since no stress is applied by the spring material 22 to the center of the semiconductor wafer 21, there will be no damage to the semiconductor wafer 21.
However, due to the worker's carelessness, when mounting the semiconductor wafer 21 on the planetarium 5 or removing the semiconductor wafer 21 on which a vapor-deposited film has been formed from the planetarium 5, the flange portion 25 of the dish-shaped member 24 may There have been cases where the top surface of the semiconductor wafer 21 was scratched and the aluminum electrode was damaged, or the semiconductor wafer 21 was dropped and damaged. Even considering such accidents, this invention reduces the number of scratches on the aluminum electrode on the top surface of the semiconductor wafer 21 to less than 1/2.
The number of breakage accidents in No. 1 has been reduced to less than 1/4.

FIG. 5 shows an enlarged sectional view of a main part of a second embodiment of this invention. The feature of this embodiment is that in addition to a step 20 at the periphery of the through hole 19 of the planetarium 5, the thickness t of the semiconductor wafer 21 is approximately equal to the step 20.
The semiconductor wafer 21 is placed on the lower stage 20, and a dish-shaped member 27 having the same shape as the dish-shaped member 24 but with a slightly larger diameter is provided on the upper stage 26.
The flange portion 28 of the flange portion 28 is placed thereon. In this embodiment, the diameter of the dish-shaped member 27 is larger than the diameter of the dish-shaped member 24 of the first embodiment, so
When the semiconductor wafer 21 is attached to or removed from the planetarium 5, accidents in which the aluminum electrode on the upper surface of the semiconductor wafer 21 is damaged by the flange portion 28 of the dish-shaped member 27 are further reduced. The load of step part 2
6 and is hardly added to the semiconductor wafer 21, which has the advantage of drastically reducing accidents of damage to the semiconductor wafer 21.

In each of the embodiments described above, the spring member 22 and the dish-shaped members 24 and 27 may be configured separately, but they may also be configured integrally. In such a case, there is an advantage that the effort of attaching and removing the dish-shaped members 24 and 27 can be saved. In this case, if the spring material 22 is allowed to slide slightly on the dish-like members 24, 27, the pressing force by the spring material 22 can be changed while the dish-like members 24, 27 are held in place. . .

Although the above embodiments have all been described with reference to the case of forming electrodes on semiconductor wafers, the present invention can also be implemented in the same way when forming vapor deposited films on wafers made of ceramic or glass.

As described above, in this invention, a dish-shaped member having a flange on the periphery is brought into contact with the upper surface of the wafer in a face down state, and only the peripheral edge of the wafer is pressed by the dish-shaped member. Not only can it prevent the wafer from going around to the upper surface side, but it also has the excellent effect of drastically reducing the occurrence of scratches on the wafer's upper surface and damage to the wafer.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the schematic structure of the vapor deposition machine, Figure 2
The figure is a perspective view of the planetarium, and Figure 3 is the same as in Figure 2 for explaining the conventional wafer holding mechanism.
FIGS. 4 and 5 are enlarged sectional views of main parts taken along the line, and FIGS. 4 and 5 are enlarged sectional views of main parts showing different embodiments of the wafer holding mechanism of this invention. 5...Planetarium, 19...Through hole, 20,
26...Step part, 21...Semiconductor wafer, 22...
...Spring material, 24, 27...Dish-shaped member, 25, 28
...Flange part, d...Step difference between step parts 20 and 26,
t...Thickness of the semiconductor wafer 21.

Claims (1)

[Claims for Utility Model Registration] (1) A vapor deposition machine in which a wafer is placed on the stepped portion of a planetarium having a plurality of through holes with stepped portions on the periphery, and the upper surface of the wafer is pressed by a spring material. In the wafer holding mechanism, a dish-shaped member having a flange portion on the periphery is brought into contact with the top surface of the wafer in a face down state, and the top surface of the dish-shaped member is pressed by a spring material.
A wafer holding mechanism for a vapor deposition machine, characterized in that only the peripheral edge of the wafer is pressed by a flange portion of a dish-shaped member. (2) the step portion has two steps, and the step difference between the upper step and the lower step is set to be approximately equal to the thickness of the wafer;
A wafer holding mechanism for a vapor deposition machine according to claim (1) of the registered utility model, wherein a wafer is placed on the lower stage and a dish-shaped member is placed on the upper stage.