JPH079927B2 - Semiconductor wafer attachment / detachment mechanism - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a mechanism for attaching and detaching a semiconductor wafer to and from a flat plate such as a susceptor of a vapor phase growth apparatus.

[Technical background of the invention]

The manufacturing of semiconductor devices includes many steps of vapor-phase growth of an insulating film such as a SiO ₂ film or a polycrystalline silicon layer on the surface of a semiconductor wafer. It is performed by placing it horizontally on top.

By the way, when placing and taking out a semiconductor wafer on the susceptor of the vapor phase growth apparatus, the vacuum chuck shown in FIG. 6 or 7 is conventionally used. In these figures, 1 is a vacuum chuck. The vacuum chuck comprises a cup section 2 and a suction tube section 3. In addition, 4 is a susceptor of a vapor phase growth apparatus, 5 is a heater block. In any case, the vacuum chuck 1 sucks vacuum from the suction tube part 4 to reduce the internal space of the cup part 3, and the semiconductor wafer 10 is sucked and held at the opening end of the cup part to attach and detach the semiconductor wafer. Is.

The difference between the vacuum chucks of FIGS. 6 and 7 is that in FIG. 6, the outer peripheral ridge of the semiconductor wafer is brought into contact with the inner surface of the cup to adsorb it, whereas in FIG. 7, a flat portion is provided at the lower end of the cup. The point is that the flat portion is brought into contact with the surface of the semiconductor wafer to adsorb it.

[Problems of background technology]

As described above, since the mechanism conventionally used for attaching and detaching the semiconductor wafer is based on vacuum suction, there are the following problems.

First, since the back surface of the semiconductor wafer 10 is a mirror surface, the semiconductor wafer 10 and the susceptor 4 are in close contact with each other in a vacuum state and cannot be reliably removed by a holding force by suction.

Secondly, it is difficult to set the strength of vacuum suction because the required suction force differs depending on the degree of close contact between the semiconductor wafer 10 and the susceptor 4, and if the strength is set to a higher value, the wafer will warp and will crack when it is remarkable.

The third problem is to attach the dust to the surface of the wafer, which does not suck in the dust as well.

Fourthly, since the chucking cup contacts the wafer, there are problems that the surface of the wafer is scratched or dust is attached.

[Object of the Invention]

The present invention has been made in view of the above circumstances, and provides a semiconductor wafer attaching / detaching mechanism capable of avoiding all conventional problems by means of mechanically holding the semiconductor surface without contacting the semiconductor surface.

[Outline of Invention]

A semiconductor wafer attaching / detaching mechanism according to the present invention is provided at a peripheral portion of a wafer mounting position of a flat plate susceptor on which a semiconductor wafer mounted in a vapor phase growth apparatus is mounted, so that a part thereof is located below the semiconductor wafer. And three or more recesses, a chucking rod vertically arranged at a position corresponding to each of these recesses, and a lower end provided with a collar portion smaller than the diameter of the recess, and a chucking rod for each chucking rod. A supporting body for supporting the chucking rod, wherein the chucking rod is hung from the supporting body under its own weight, and supports the chucking rod so that the chucking rod can be pushed upward from the supporting body; An opening / closing mechanism for making the closed state close to the side end surface of the semiconductor wafer and the opened state separated from each other, and a single cam plate rotatable by a drive shaft and a peripheral surface of the cam plate. An opening / closing mechanism including an urging member for pressing the support, and a lifting mechanism for simultaneously moving the chucking rods suspended on the support and the opening / closing mechanism as a set up and down. When chucking a semiconductor wafer, with the chucking rod open, lower the chucking rod until the collar portion abuts the bottom surface of the recess and is pushed upward from the support, and then the recess bottom surface. After the chucking rod is closed along with the sliding of the flange portion above, the chucking rod is raised so that the semiconductor wafer is locked and held by the collar portion. It is characterized by having done.

As mentioned above, in the present invention, not vacuum suction,
Since the semiconductor wafer is held and held on the flat plate by mechanical locking, all the conventional problems can be avoided.

Example of Invention

1 to 3 are explanatory views showing a semiconductor wafer attachment / detachment mechanism according to an embodiment of the present invention.

In FIG. 1, reference numeral 11 is a flat plate such as a susceptor in the vapor phase growth apparatus, and the semiconductor wafer 10 is located at a position indicated by a chain double-dashed line in the figure.
Is placed. In the state on the surface of the plate 11, four circular recess 12 ₁ to 12 ₄ are provided along the periphery of the semiconductor wafer is mounted, the semiconductor wafer as shown in the figure covering part recesses of each It is supposed to be placed. On the other hand, on the flat plate 11, chucking four of which moves King rods _131-134 are arranged vertically at a position corresponding to each of the recesses 12 ₁ to 12 _4. Collar portions 14 _{1 to} 14 _{4 each} having a diameter smaller than the diameter of the recessed portions 12 _{1 to} 12 ₄ are formed at the tips of the chucking rods so as to project laterally. The overall structure of each chucking rod is as shown in FIGS. 2 (A) and 2 (B).

FIG. 2 (A) is a perspective view showing the whole of the chucking rod 13 _1, and FIG. (B) is a sectional view thereof. As shown, Chakkinbu rod 13 ₁ is provided through the casing 15 _1, the casing 15 ₁ by a stopper 16 ₁ formed at an upper end
Is locked to. A bearing member 17 ₁ is built in the casing 15 ₁ , and the chucking rod 13 ₁ falls by its own weight into the state shown in the figure, and moves upward when pushed up from below. An arm 18 ₁ is provided on the casing 15 ₁ , and a fulcrum member 19 ₁ is provided on the other end of the arm 18 ₁ . Then, the whole by axially supporting the fixed rotation axis 21 ₁ that is suspended from above fulcrum member is fixed. Further, a roller 20 ₁ is provided on the top surface of the casing 15 ₂ so as to project outward. The structure of the other chucking rods 13 _{2 to} 13 ₄ is the same.

FIG. 3 is a plan view of the state of FIG. 1 seen from above, showing the state of attachment of the four chucking rods. As shown, the chucking rods 13 ₁ and 13 ₂ are arranged adjacent to their respective fulcrum members 19 ₁ 19 ₂ and are biased inward by a spring 21 adjusted between the respective arms 18 ₁ and 18 _2. ing. The same applies to the chucking bars 13 ₃ and 13 ₄ . Further, a cam 22 is provided in a central portion surrounded by the chucking rods, and is supported by the cam and a fixed rotary shaft that is hung from above. The rollers 20 _{1 to} 20 ₄ provided on the casing of each chucking rod are urged by the spring 21 and are in contact with the side end surface of the cam 22. Therefore, the rotation of the cam 22 causes the arms 18 ₁ and 18 ₂ and the arms 18 ₃ and 18 ₄ to open and close as indicated by arrows in the figure.

The chucking device as a whole can be moved up and down, and can be moved horizontally.

The operation of the detaching mechanism having the above structure will be described below.

First, as shown in FIG. 4 (A), the chucking device is moved to a predetermined position on the flat plate 11 on which the semiconductor wafer is placed, and the chucking rods 13 _{1 to} 13 ₄ are moved to the corresponding recesses 12 _{1 to} 12 respectively. _Four
On top. At this time, the chucking rod is in an open state as shown in FIG.

Then, by lowering the chucking device, the fourth
The flange portion 14 _{1-14 4} provided at the tip of each chucking rod as shown in FIG. (B) contacting the bottom surface of each recess. in this case,
As shown in FIG. 5, chucking bar stoppers 16 ₁ to 1
6 ₄ is desirable so as to lower the chucking device to rise lifting the locking surface of the casing by a predetermined distance d. This is to ensure certainty.

Then, by rotating the cam 22, the chucking stick
_131-134 closed, as shown in FIG. 4 (C), the flange portion 14 ₁
To enter -14 ₄ to periphery subordinates semiconductor wafer 10.

Next, if the device is raised with the chucking rods closed, the chucking rods will relatively fall from the state shown in FIG. 5 until the stopper is engaged with the top surface of the casing and then rise. As a result, as shown in FIG. 4 (D), the semiconductor wafer has its peripheral edge portion at the collar portion 14 _{1 at the} lower end of the chucking rod.
Lifted in locked state to -14 _4. After that, the chucking device can be moved to a predetermined position to open the chucking rod, and the semiconductor wafer can be taken out.

When the semiconductor wafer 10 is mounted on the flat plate 11 at a predetermined position, the above operation may be performed in reverse.

Since the desorption mechanism of the above embodiment is based on mechanical chucking, it is much more reliable than the conventional desorption mechanism using chucking by vacuum suction, and sucks dust together and attaches it to the wafer. There is no such thing. In addition, since the surface of the semiconductor wafer is not contacted with anything, it is possible to avoid a situation in which it is scratched.

Further, since the safety span d is provided as described with reference to FIG. 5, even when the susceptor is in a poor flat state, the chucking can be reliably performed.

〔The invention's effect〕

As described in detail above, since the semiconductor wafer attaching / detaching mechanism according to the present invention employs mechanical chucking,
By using chucking by vacuum suction, it is possible to solve all the problems that have occurred in the conventional attachment / detachment mechanism.

[Brief description of drawings]

1 to 3 and 5 are explanatory views showing the structure of a semiconductor wafer attaching / detaching mechanism according to an embodiment of the present invention, and FIG. 4 is an explanatory view showing its action, FIG. 6 and FIG. FIG. 7 is an explanatory view showing a conventional attaching / detaching mechanism. 11 ... Flat plate such as susceptor, 12 _{1 to} 12 ₄ ... Recessed portion, 13 _{1 to} 13 ₄ ... Chucking rod, 14 ₁ , 14 ₄ ... Collar portion, 15 ₁ ... Casing, 16 ₁
… Stopper, 17 ₁ … Bearing member, 18 ₁ … Arm, 19 ₁
... fulcrum member, 20 ₁ ... fixed rotating shaft, 21 ... spring, 22 ...
cam.

Claims (1)

[Claims] 1. At least three semiconductor wafers, which are installed in a vapor phase growth apparatus, are provided at a peripheral portion of a wafer mounting position of a flat plate susceptor on which a semiconductor wafer is mounted so that a part thereof is located below the semiconductor wafer. Recesses, a chucking rod vertically arranged at a position corresponding to each of the recesses, and a collar portion having a collar portion smaller than the diameter of the recess at the lower end, and a support for supporting each of the chucking rods. A support body for supporting the chucking rod so that the chucking rod is hung from the support body under its own weight, and the chucking rod can be pushed upward from the support body; An opening / closing mechanism for setting a closed state close to the side end surface and an opened state separated from the side end surface, wherein one cam plate rotatable by a drive shaft and the support body are pressed against the peripheral surface of the cam plate. Biasing member And an elevating mechanism for simultaneously moving up and down as a set of the chucking rods and the opening / closing mechanism suspended from the support, and the chucking is performed when the semiconductor wafer is chucked. With the rod open, lower the chucking rod until the collar comes into contact with the bottom surface of the recess and is pushed upward from the support, and then slide the collar on the bottom surface of the recess. Accordingly, after the chucking rod is closed, the chucking rod is raised to hold and hold the semiconductor wafer on the collar portion. mechanism.