JPH0648859Y2 - Wafer support - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The present invention is used for a plasma device or the like for manufacturing LSI, VLSI, etc. When storing and taking out a semiconductor wafer by an elevator inside and outside a reaction chamber of the plasma device. The present invention relates to a wafer support that ensures the support of a wafer on the wafer, and particularly improves the efficiency of plasma processing on the back surface of the wafer.

(Prior Art) A plasma device is used for processing such as etching and ashing when manufacturing LSI or VLSI. In order to insert a wafer into a reaction chamber (chamber) of this plasma apparatus and to take out a wafer from the reaction chamber, a quartz wafer support called a boat that supports a plurality of devices in parallel is used. .

(Problems to be Solved by the Invention) When a wafer support is supported horizontally by a horizontal movement relative to the reaction chamber, the wafer support is supported by the wafer support itself. If you support the wafer in an upright position at the bottom,
Sufficient because they can maintain their spacing. However, such a horizontal plasma device has a large installation area,
In the semiconductor industry of this kind, which is trying to reduce costs from all points of view, it is not much liked.

For this reason, a vertical plasma device that requires a small installation area has been proposed, and at present, it is becoming the mainstream. In this vertical plasma apparatus, the wafer support is moved up and down by an elevator arranged below the vertical reaction chamber.

The wafer support used in this conventional vertical plasma apparatus has a plurality of rod-shaped support frames standing on a pedestal, and the upper ends of the support frames are connected and fixed by a substantially C-shaped ring frame. A support groove for accurately maintaining the wafer support interval is provided inside the wafer.

However, according to this conventional wafer support, the wafer may jump out toward the front of the support and fall due to vibration or the like when the elevator moves up and down. In addition, since the upper part of the support is an open structure, the one set near the upper part may be damaged during plasma processing in the reaction chamber, which may cause a significant decrease in product yield. It was one.

Not only that, when chip patterns are formed on both front and back surfaces of a wafer to improve the efficiency of plasma processing, the back surface of the supported wafer must contact the bottom surface of the supporting groove when the wafer is supported by a support tool. Therefore, no plasma treatment is performed at the contact portion. for that reason,
If the support groove is formed shallow to reduce the contact area,
The support of the wafer became uncertain, and the inserted wafer was sometimes dropped due to vibration during transportation or the like.

On the other hand, since the support groove for supporting the wafer is provided inside the support frame, the support frame itself must have a certain thickness or more. The frame itself weakens the strength, and as a result, the mechanical strength is insufficient, and the frame may be damaged by an external impact or the like.

Therefore, the present invention has been devised in view of the above-described conventional circumstances, and in particular, enables plasma processing of a chip pattern formed on the back surface of a wafer to be performed efficiently and has sufficient mechanical strength. Another object of the present invention is to provide a wafer support tool capable of preventing the damage, and further, preventing the wafer set in the upper and lower positions of the support tool itself from being damaged by plasma.

(Means for Solving the Problems) In order to achieve the above-mentioned object, according to the present invention, a board-shaped base mounted on an elevating base in an elevator in a vertical plasma apparatus, and this base Located parallel to the table, a top plate that forms a storage area together with the base that can store a predetermined number of semiconductor wafers, and is located on the left and right of the storage area entrance where the wafer is inserted substantially parallel to the base surface,
It is a rod-shaped member that stands upright between the base and the top plate, and has an inlet support frame on which the peripheral edge of the wafer is placed and which has an inlet support protrusion to support it. It is characterized in that it comprises a backside support frame, which is a rod-like member standing upright between the base and the top plate, on which a peripheral edge of the wafer is placed, and a backside support projection for supporting the wafer is formed.

The entrance support frame and the back support frame are hollow, and the center of the storage area can be configured by inserting and fixing the entrance support projection and the back support projection on the peripheral wall.

Further, the damage prevention upper plate may be fixed to each of the inlet support frame and the inner part support frame at the lower position of the top plate with a slight distance from the top plate.

Furthermore, the lowermost wafer supported by the inlet support protrusion of the inlet support frame and the inner support protrusion of the inner support frame is separated from the lowermost position wafer by a slight distance from the inlet support frame and the inner support frame, respectively. The damage prevention lower plate can be fixed and configured.

(Operation) In the wafer support according to the present invention, the wafer is directly stored from the storage area entrance between the base and the top plate, and the entrance support projection of the entrance support frame and the back support projection of the back support frame are provided. The peripheral portion of the wafer is placed and supported on each. Then
It is housed in a reaction chamber by an elevator in a plasma device and plasma-processed.

At this time, the inlet support projections and the back support projections reliably support the contact area with the back surface of the wafer in a reduced state, and also make the plasma processing of the chip pattern on the back surface of the wafer efficient.

During the plasma processing in the reaction chamber, the plate-shaped top plate sufficiently protects the wafer near the top plate and avoids damage by the plasma during the plasma processing.

In particular, when used in a vertical plasma device, the plasma heat that rises to the upper part is retained by the heat space between the top plate and the damage prevention upper plate, and the heat for the wafer placed on the upper part is retained. Prevents damage more effectively.

On the other hand, the damage prevention lower plate avoids damage to the chip pattern formed on the back surface of the wafer supported at the lowest position by plasma during the plasma processing.

Further, since the inlet support frame having the inlet support protrusions and the inner support frame having the inner support protrusions each have a hollow shape, the mechanical strength can be reduced by reducing the diameter. Increase the overall robustness.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

Reference numeral 10 shown in the drawing is a predetermined vertical type plasma device, and as shown in FIG. 4, the semiconductor wafer W stepwise supported by the supporting device of the present invention is arranged in the lower portion of the elevator 11. It is designed to be inserted into the reaction chamber (chamber) 12 arranged in the upper part by rising, and after the plasma processing, it is lowered and taken out from the reaction chamber 12.

Thus, as shown in FIG. 1 to FIG. 3, the supporting tool in this invention has a board-shaped base 1 placed on an elevating base of an elevator 11 and a base 1 substantially corresponding to the base 1. A top plate 2 which is parallel and forms a storage area capable of storing a predetermined number of wafers W together with the base 1, and is located on the left and right of the storage area entrance into which the wafer W is inserted, substantially parallel to the surface of the base 1. , A base 1 and a bar-shaped entrance support frame 3 standing upright between the top plate 2 and
It is located in the back part of the storage area and is also composed of a base 1 and a rod-shaped back support frame 5 standing upright between the top plates 2, and is entirely made of transparent quartz.

Each of the inlet support frame 3 and the back support frame 5 is formed in a hollow shape as shown in FIG. 3, and is formed to have a predetermined diameter in consideration of the load of the wafer W to be supported and the like.

Then, the inner edge of each of the inlet support frame 3 and the rear support frame 5, that is, the center of the storage area, is provided with the peripheral edge portion of the wafer W, and the inlet support protrusion 4 and the rear support protrusion 6 that support the wafer W are supported, respectively. To project. These inlet support protrusion 4 and back support protrusion 6
Is formed in the shape of a pin having a circular cross section, and the center of the storage area of the inlet support frame 3 and the back support frame 5 is inserted into the peripheral wall and fixed by abutting the inserted end against the inner surface of the peripheral wall. (See Fig. 3). Further, the inlet support protrusion 4 and the back support protrusion 6 themselves are the wafer W mounted on the upper surface thereof.
The contact area with the wafer W is considered to be as small as possible, and the reliability of the wafer W support can be improved by selecting the length.

Wafer W supported by inlet support frame 3, inlet support protrusion 4 inserted through and fixed to rear support frame 5, and rear support protrusion 6.
The rear is inclined downward, so that the edge of the base 1 on the back support projection 6 is smaller than the edge of the base 1 on the entrance support projection 4 compared to the edge of the base 1. No. 1 is located at the alligator position (see FIG. 2).

Further, a damage prevention upper plate 7 is arranged and fixed at a lower position of the top plate 2 by fixing the entrance support frame 3 and the back support frame 5 to the top plate 2 with a slight space therebetween. Upper plate 7
Form a heat space with the top plate 2. That is, when plasma processing is performed by the plasma device 10 having a vertical configuration, the plasma heat generated during the processing is retained in the thermal space between the top plate 2 and the damage prevention upper plate 7. .

The damage prevention upper plate 7 is not limited to being fixed substantially parallel to the top plate 2 as shown in the drawing, and although not shown in the drawing, the damage preventing upper plate 7 is substantially parallel to the wafer W supported by being inclined downward. When the wafer W is processed, it is possible to ensure the plasma processing especially for the uppermost wafer W by being fixed so as to be.

Further, the lowermost wafer W supported by the inlet supporting protrusions 4 of the inlet supporting frame 3 and the inner supporting protrusions 6 of the inner supporting frame 5 and the inlet supporting frame 3 at a lower position with a slight distance therebetween,
A damage prevention lower plate 8 is arranged and fixed to each of the back support frames 5.

The damage prevention upper plate 7 and the damage prevention lower plate 8 in the illustrated example are
The inlet support projection 4 and the back support projection 6 are fixed while being placed on the respective upper surfaces, but the fixing structure is not limited to this.

Although the base 1, the top plate 2, the damage prevention upper plate 7 and the damage prevention lower plate 8 are each formed in a disk shape, the shape is not limited to this. Further, since the base 1 serves as a support substrate in the supporting device of the present invention, it is formed thicker than the top plate 2, but it can be set arbitrarily.

Further, the disk-shaped base 1 is provided with a positioning hole 9 for positioning at a specific position, and is used for positioning when the invention supporting tool itself is placed on the elevator base of the elevator 11. It is designed to be used.

The storage area is obtained as a space between the base 1 and the top plate 2, and the wafer W is substantially parallel to the surfaces of the base 1 and the top plate 2 in a direction orthogonal to the entrance support frame 3. It is stored directly in the storage area. The space between the left and right entrance support frames 3 at the entrance of the accommodation area is not smaller than the width of the wafer W, and the distance between the inner edges of the entrance support protrusions 4 is not small. In order to prevent W from coming out easily, when viewed from a plane, it is assumed that it is positioned slightly forward of the diametrical direction with respect to the center of the base 1 in the storage area (see FIG. 3).

It should be noted that the number of the inlet support projections 4 and the depth support projections 6 are usually set to 50 as one unit in batch processing, so the number is 50, but is limited to that number. Of course it is not a thing.

In addition, although the back part support frame 5 itself is arranged in two in the drawing, it may be one, or three or more.

Next, to explain an example of the use, as shown in FIG. 4, the plasma apparatus 10 is set upright on the elevating base of the elevator 11 via the base 1. Then, the wafer W may be stored directly from the storage area entrance between the damage prevention upper plate 7 and the damage prevention lower plate 8, and the wafer W is supported by the entrance support projection 4 and the back support frame 5. The peripheral portions of the wafer W are placed on and supported by the respective inner-portion support protrusions 6.

After storage and support, the reaction chamber 12
It is stored and taken out inside and outside.

At this time, if the wafer W supported by the inlet support projections 4 and the back support projections 6 is tilted downward at the rear, the back of the wafer W will always be backed by the vibration associated with the elevation of the elevator 11. Since the back portion of the support frame 5 has a slanted back portion, the front portion in the storage area does not jump out.

(Effect of the Invention) Therefore, as described above, the wafer support according to the present invention includes the board-shaped base 1 mounted on the elevating base of the elevator in the vertical plasma device 10, and the base. 1
A top plate 2 that is substantially parallel to the base 1 and that forms a storage area in which a predetermined number of semiconductor wafers W can be stored, and a storage area entrance in which the wafer W is inserted substantially parallel to the surface of the base 1. An entrance support frame 3 in which the entrance support projections 4 are formed, which are rod-shaped and are erected between the base 1 and the top plate 2 on the left and right, and on which the peripheral edge of the wafer W is placed, and a storage area. In the back support, the back support 6 is formed in a bar shape that is also positioned in the back of the wafer 1 and stands upright between the base 1 and the top plate 2 and on which the peripheral edge of the wafer W is placed and supported. Since the frame 5 is provided, the contact area for supporting the wafer W by the entrance support frame 3 and the back support projections 6 is small especially when chip patterns are formed on both front and back surfaces of the wafer. The efficiency of the plasma treatment can be improved.

In addition, the plate-shaped top plate 2 sufficiently protects the wafer W near the top plate 2 in the storage area, greatly helps to avoid damage due to plasma during plasma processing, and significantly improves the product yield. .

Further, during the plasma processing in the reaction chamber 12, the top plate 2 and the damage prevention upper plate 7 sufficiently protect the wafer W in the vicinity of the top plate 2 and avoid the damage due to the plasma during the plasma processing. In particular, when the plasma apparatus 10 is configured as a vertical type to perform plasma processing, the plasma heat generated during the processing rises, so that the heat is retained at the upper part of the wafer support of the present invention, and It is possible to prevent heat damage to the wafer W. That is, the plasma heat rising to the upper part is retained in the thermal space between the top plate 2 and the damage prevention upper plate 7, so that the heat damage to the wafer W arranged on the upper part is made more effective. Therefore, the wafer W at that position can be prevented from being thermally damaged, and the product yield can be improved.

On the other hand, the damage prevention lower plate 8 prevents the chip pattern formed on the back surface of the wafer W supported at the lowermost position from being damaged by the plasma during the plasma processing. The plasma processing efficiency of the formed chip pattern is greatly improved.

Further, the inlet support frame 3 having the inlet support protrusions 4 and the inner support frame 5 having the inner support protrusions 6 each have a hollow shape to reduce the diameter. However, the mechanical strength is increased and the overall robustness is increased. By increasing the overall robustness, the load of the wafer W accommodated and supported in the accommodation area is sufficiently supported, the supporting interval of the wafer W supported in a stepwise manner is maintained, and reliable plasma processing is achieved.

As described above, according to the present invention, the plasma treatment of the chip pattern formed on the back surface of the wafer can be efficiently performed, the mechanical strength is sufficient, and the damage can be prevented. There are excellent effects such as avoiding damage to the wafer set in the upper position and the lower position of the tool itself due to plasma and preventing thermal damage during plasma processing in the vertical plasma apparatus.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a perspective view, FIG. 2 is a side sectional view of an essential part in a state of supporting a semiconductor wafer, FIG. 3 is a plan view, and FIG. [Fig. 3] is a cross-sectional view of a state of use in a plasma device. W ... Wafer, 1 ... Base, 2 ... Top plate, 3 ... Entrance support frame, 4 ... Entrance support projection, 5 ... Back support frame, 6 ... Back support projection,
7 ... Damage prevention upper plate, 8 ... Damage prevention lower plate, 9 ... Positioning hole, 10 ... Plasma device, 11 ... Elevator, 12 ... Reaction chamber.

Claims (4)

[Scope of utility model registration request] 1. A board-shaped base placed on an elevating base of an elevator in a vertical plasma apparatus, and a storage area which is substantially parallel to the base and is capable of storing a predetermined number of semiconductor wafers. The top plate that is formed with the base and the rods that are positioned on the left and right at the entrance of the storage area in which the wafer is inserted and are approximately parallel to the base surface and stand upright between the base and the top plate. Is placed and is located at the back of the entrance support frame in which the entrance support protrusions are formed to support it, and is a rod-like shape that is also erected between the base and the top plate, and the peripheral edge of the wafer is A wafer support tool, comprising: a back support frame on which a back support protrusion is formed to support and is mounted. 2. The inlet support frame and the back support frame are hollow,
2. The wafer support according to claim 1, wherein the center of the storage area is provided with an entrance support projection and a back support projection through the peripheral wall. 3. The wafer support device according to claim 1, wherein a damage prevention upper plate is fixed to each of the inlet support frame and the back support frame at a position below the top plate with a slight distance from the top plate. 4. An entrance support frame and a back support frame at a lower position with a slight distance from the wafer at the lowest position supported by the entrance support projection of the entrance support frame and the back support projection of the back support frame. 4. The wafer support according to claim 1, wherein a damage prevention lower plate is fixed to each of them.