JP2001053015A - Semiconductor wafer transfer device in vertical furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor wafer transfer device in a vertical furnace, which allows an effective and high-yield transfer or collection of a plurality of semiconductor wafers stored in a cassette into or out of a boat of the vertical furnace. SOLUTION: A cassette 2 storing semiconductor wafers A is disposed facing a boat 1. Being supported horizontally, the semiconductor wafers A are collectively transferred from the cassette 2 to the boat 1 by comb-like loaders 61 and 71 of a pusher mechanism 6 and a receiver mechanism 7. Before and after being transferred, the semiconductor wafers A are collectively transferred between support shelves of the cassette 2 and the loaders 61, 71 by vertically moving the whole cassette 2 by a cassette elevation means 5. Similarly, the semiconductor wafers A are collectively transferred between the loaders 61, 71 and wafer support sections 12 of the boat 1 by vertically moving the whole boat 1 with a boat elevation means 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer transfer apparatus for a vertical furnace in which a plurality of semiconductor wafers are vertically arranged in multiple stages and heat treatment is performed.

[0002]

2. Description of the Related Art As a heat treatment furnace for heat treating a disc-shaped semiconductor wafer such as Si, there is a vertical furnace in which a plurality of semiconductor wafers are arranged in a vertical direction with the board surface being horizontal. In the vertical furnace, a semiconductor wafer support member called a boat for arranging the semiconductor wafer at the center of the cylindrical heater is used. In this boat, a plurality of quartz rods standing vertically are arranged along the outer periphery of the semiconductor wafer and avoiding the front side so that the semiconductor wafer can be inserted from the front side of the vertical furnace. A plurality of grooves orthogonal to the axis are formed in the quartz bar at predetermined intervals in the axial direction.Each semiconductor wafer is held horizontally by grooves of the same height of each quartz bar, and is vertically spaced at predetermined intervals. Are arranged in plurals. On the other hand, the semiconductor wafers are transported from the previous process using a cassette that can be collectively stored without being in contact with each other. For this reason, the operation of transferring semiconductor wafers to the boat involves removing semiconductor wafers one by one from the cassette, inserting the end into the groove of the boat while keeping the board surface horizontal, and removing another semiconductor wafer. It is arranged in the vertical direction by being inserted in another groove in the same manner.
In the transfer operation, means for holding both ends of the semiconductor wafer for handling the semiconductor wafers one by one, and a vacuum chuck for sucking the board surface of the semiconductor wafer are used.

[0003]

However, the above-mentioned conventional transfer means has a problem that the work time is long and the efficiency is low because the semiconductor wafers are transferred one by one.
Further, the semiconductor wafer has a thickness of one of the thickness of a normal semiconductor wafer.
In the case of a thickness of about 100 μm, which is about / 3, cracks and edges may be lost during transfer due to the clamping force at both ends acting on the semiconductor wafer and the suction force of the vacuum chuck. However, there is a problem that the yield is reduced. In view of the above conventional problems, the present invention
It is an object of the present invention to provide a vertical furnace semiconductor wafer transfer apparatus capable of efficiently transferring a plurality of semiconductor wafers stored in a cassette to a vertical furnace boat with good yield or recovering the same.

[0004]

In order to achieve the above object, a vertical furnace according to the present invention holds a plurality of disc-shaped semiconductor wafers in a multi-stage manner with a gap provided between them by a wafer support portion of a boat. In a semiconductor wafer transfer device of a vertical furnace that performs heat treatment in a state, the device has a support shelf that supports semiconductor wafers configured in multiple stages at the same interval as the wafer support portion, and the support shelf is divided into right and left, A cassette provided with a space portion, a cassette support portion for holding the cassette facing the front of the boat, and a projection portion connected to the cassette support portion and arranged at the same interval as the wafer support portion. A push mechanism for moving the comb-shaped loader provided to the boat through the space of the cassette with the projections inserted between a plurality of semiconductor wafers; and the comb-shaped loader. The other end of the semiconductor wafer, one end of which is supported by the die, is collectively supported by the same comb-shaped loader as the push mechanism from the opposite direction of the push mechanism, and interlocked with the push mechanism. A receiving mechanism for moving horizontally while maintaining a constant interval, a cassette elevating means for transferring the semiconductor wafer between the protrusion and the support shelf by raising and lowering the cassette support, It is characterized by comprising a boat elevating means provided at a lower part of the boat for transferring the semiconductor wafer to and from the wafer support part and elevating the boat.

[0005] According to the semiconductor wafer transfer device of the vertical furnace having the above-described structure, each of the comb-shaped loaders of the receiving mechanism and the push mechanism is advanced toward the semiconductor wafer stored in the cassette in multiple stages. Thereby, each semiconductor wafer can be supported in a state of being sandwiched from the front and rear by the respective projecting portions of both comb tooth loaders. In addition, the push mechanism and the receiving mechanism are linked to each other and horizontally moved while maintaining a constant interval, so that the semiconductor wafers can be moved horizontally between the cassette and the boat while being held horizontally. Further, the cassette and the boat can be moved in the vertical direction by the cassette lifting and lowering means and the boat lifting and lowering means. The semiconductor wafer can be collectively delivered while being supported from below. Therefore, no damage is given to each semiconductor wafer.

In the semiconductor wafer transfer device, the first comb-shaped loader and the second comb-shaped loader each have a loader positioning plate facing each other in the horizontal direction, and the positioning plates are connected to each other. It is preferable to keep the above-mentioned constant interval by making contact with each other (claim 2). In this case, the distance between the first comb-shaped loader and the second comb-shaped loader is kept constant by bringing the positioning plates into contact with each other, so that the semiconductor wafer is moved by the comb-shaped loader. Can be prevented from acting directly.

[0007]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a main part front view showing one embodiment of a semiconductor wafer transfer device for a vertical furnace according to the present invention. This vertical type semiconductor wafer transfer apparatus includes a boat elevating means 3 for vertically moving a boat 1 installed in a vertical furnace R, a cassette 2 for storing semiconductor wafers A, and a vertical type. A cassette supporting portion 4 provided on the front side (right side in the figure) of the furnace R and supporting the cassette 2; and a cassette lifting / lowering means 5 provided at a lower portion of the cassette supporting portion 4 and moving the cassette vertically.
A push mechanism 6 connected to the cassette support 4 for holding the semiconductor wafer A and pushing the semiconductor wafer A toward the boat 1;
The main part is constituted by a receiving mechanism 7 provided on the rear surface side (left side in the figure) of the vertical furnace R and holding the semiconductor wafer A in conjunction with the push mechanism 6 and transferring the semiconductor wafer A to the boat 1.

The boat 1 comprises four upright quartz rods 1
1 and housed inside the vertical furnace R. The four quartz rods 11 are provided at four places avoiding the front side so that the semiconductor wafer A can be taken in and out of the boat 1 from the front side of the vertical furnace R, and arranged at the center of the vertical furnace R. Are arranged along the outer periphery of the semiconductor wafer A to be formed (see FIG. 2). The quartz rod 11 is provided with a plurality of grooves having a predetermined depth perpendicular to the axis at predetermined intervals. The semiconductor wafer A is supported by the wafer support portion 12 below each groove. The semiconductor wafer A is supported at four positions by the wafer supporting portions 12 of the quartz bars 11 at the same height as each other, and is kept horizontal. The boat elevating means 3 is provided below the boat 1. The boat elevating means 3
Is provided with a fluid pressure cylinder 31 and moves the boat 1 up and down.

The cassette 2 is an integrally formed box for storing the semiconductor wafers A and transporting the semiconductor wafers A from a previous process. Inside the cassette 2, there are provided a plurality of supporters for mounting the semiconductor wafers A. The shelves 21 are provided in multiple stages.
Each of the support shelves 21 is a pair of shelf boards 21 formed to project horizontally from the left and right side surfaces of the cassette 2 toward the inside.
b, 21c, and between the shelf boards 21b, 21c,
A space 21a is secured as a passage of the comb-shaped loader 61 of the push mechanism 6 described later (see FIG. 2). A rear opening 22 is also provided on the rear surface in the space, through which the comb tooth loader 61 passes. The cassette 2 is disposed on the cassette support unit 4 with the front opening 23 opened for inserting the semiconductor wafer A facing the boat 1 and the support shelf 21 in a horizontal state.

[0010] The cassette supporting portion 4 is provided with the cassette 2.
The cassette 2 is positioned in advance so that the supporting shelf 21 of the boat 1 and the wafer supporting portion 12 of the boat 1 face each other. The cassette support 4 is moved up and down by a cassette elevating means 5 having a fluid pressure cylinder 51 connected to a lower portion of the cassette support 4. The cassette support 4
A push mechanism 6 for holding and moving the semiconductor wafers A stored in the cassette 2 is provided above the cassette 2.

The push mechanism 6 includes a comb-shaped loader 61 for holding a predetermined number of semiconductor wafers A at one time,
A fluid pressure cylinder 62 holds the comb-shaped loader 61 at the tip of a piston rod 62a, and is disposed on the right side of the cassette 2 in FIG. The comb-shaped loader 61 has a number of projections 61a corresponding to the wafer support portions 12 of the boat 1 arranged at the same pitch as the wafer support portions 12 in the vertical direction. The protrusion 61a has a thickness that can be inserted into a gap between the stages of the semiconductor wafers A arranged in multiple stages and a width that can hold the semiconductor wafer A horizontally. When the piston rod 62a moves forward, the comb-shaped loader 61 inserts the protrusion 61a into the gap between the semiconductor wafers A through the rear opening 22 of the cassette 2. Similarly, the opposite end of the semiconductor wafer A is connected to the comb-shaped loader 71 of the receiving mechanism 7.
(See FIG. 2).

The receiving mechanism 7 is connected to a hydraulic cylinder 72 connected to a support (not shown) at the rear (left side in FIG. 1) of the vertical furnace R, and to a tip of a piston rod 72a of the hydraulic cylinder 72. The above push mechanism 6
And the same comb-shaped loader 71.

The comb-like loader 71 of the receiving mechanism 7
Passes between the quartz rods 11 and advances in the direction of the cassette 2, holds the semiconductor wafer A from the opposite direction to the comb-shaped loader 61 of the push mechanism 6, and simultaneously holds the semiconductor wafer A of the push mechanism 6. The semiconductor wafer A is moved while maintaining a constant distance from each other in conjunction with the semiconductor wafer A.
Is transferred to the boat 1 or a collecting operation from the boat 1 to the cassette 2 is performed.

Loader positioning plates 61b, 71b are provided at the uppermost and lowermost portions of the comb-shaped loaders 61, 71 of the push mechanism 6 and the receive mechanism 7, respectively. At the tips of the loader positioning plates 61b, 71b,
A concave portion 61d and a convex portion 71d are formed respectively.
When the comb-shaped loaders 61 and 71 are respectively advanced to predetermined positions inside the cassette 2, the concave portions 61 d and the convex portions 7
By contacting 1d with each other, both comb-shaped loaders 61 and 71 are held at a predetermined interval, and horizontal deflection of each other is regulated. For this reason, the distance between the base ends 61c, 71c of both comb-shaped loaders 61, 71 does not become smaller than a predetermined distance, and an external force acts on the semiconductor wafer A via the base ends 61c, 71c. Since there is no semiconductor wafer, loss of the semiconductor wafer can be prevented.

Next, the operation of transferring the semiconductor wafer A from the cassette 2 to the boat 1 will be described with reference to FIG. FIG. 3 shows two semiconductor wafers A as viewed in the axial direction of the piston rod 62a of the push mechanism 6, the left and right shelves 21b and 21c of the cassette 2 supporting the semiconductor wafers A,
The wafer support 12 of the quartz rod 11 and the comb-shaped loader 61,
7 shows the positional relationship between the projections 61a and 71a in the vertical direction. In FIG. 1, the cassette 2 is set on a cassette support portion 4, and the semiconductor wafers A are each held horizontally by a support shelf 21 of the cassette 2.
Prior to the transfer operation, as shown in FIG. 3A, the positions of the upper surfaces of the respective shelves 21b and 21c supporting the semiconductor wafer A of the cassette 2 correspond to the respective positions of the corresponding quartz rods 11. The position coincides with the position of the upper surface of the wafer support 12.

First, the comb-shaped loader 7 of the receiver mechanism 7
1 enters the inside of the cassette 2 from the rear of the vertical furnace R through the space between the quartz rods 11 of the boat 1. Next, the comb-shaped loader 61 of the pusher mechanism 6 enters the cassette 2 from the rear opening 22 of the cassette 2 (see FIGS. 1 and 2). At this time, the upper surfaces of the protruding portions 61a, 71a of the comb-shaped loader 61 of the pusher mechanism 6 and the comb-shaped loader 71 of the receiver mechanism 7 correspond to the shelves 21b, 21c and the respective wafer support portions 12.
And does not contact the semiconductor wafer A (the state shown in FIG. 3A). Next, in order to transfer the semiconductor wafer A from the cassette 2 to the comb-shaped loaders 61 and 71,
When the cassette lifting means 5 is driven to lower the cassette 2, the semiconductor wafer A is supported from below by the projections 61a, 71a of the comb tooth loaders 61, 71 as shown in FIG. Thereby, the semiconductor wafer A is separated from the shelves 21b and 21c of the cassette 2.

Next, the push mechanism 6 is driven to push out the comb-tooth loader 61, and in conjunction with this, the receiver mechanism 7 is retracted to the boat 1 side, and the semiconductor wafer A is moved to the position of the boat 1. . At this time, the wafer support portion 12 of the boat 1 is lowered in advance to a state shown in FIG. Therefore, the semiconductor wafer A does not come into contact with the wafer support 12 of the boat 1. After the movement is completed, the boat 1 is raised by the boat lifting / lowering means 3. As a result, the semiconductor wafer A is separated from the protrusions 61a and 71a and is supported from below by the wafer support 12 of the boat 1 (see FIG. 3A). In this state, the comb tooth loader 6
When the semiconductor wafers A and 71 are returned to their original positions, the operation of transferring the semiconductor wafer A to the boat 1 is completed. When the semiconductor wafer A is collected from the boat 1 into the cassette 2, the operation is reversed.

With the above structure, the semiconductor wafer A is held horizontally by the comb-shaped loaders 61 and 71 of the pusher mechanism 6 and the receiver mechanism 7 while the semiconductor wafer A is housed in the cassette 2. Can be moved. Independently of this moving operation, the cassette supporting shelf 21 and the wafer supporting portion 12 of the boat 1 are vertically moved up and down, so that the comb-teeth loaders 61 and 71 and the shelf plates 21b and 21c of the cassette 2 are moved up and down. , Comb tooth loaders 61, 7
The semiconductor wafer A can be transferred between the wafer support 1 and the wafer support portion 12 of the boat 1 without damaging the semiconductor wafer A. For this reason, work efficiency and yield can be improved.

[0019]

As described above, according to the semiconductor wafer transfer device of the vertical furnace according to the first aspect, when transferring the semiconductor wafer from the cassette to the boat and collecting the semiconductor wafer from the boat to the cassette, the semiconductor wafer is transferred from the cassette to the boat. Since the semiconductor wafer A is supported and supported from below by the toothed loader and can be collectively moved and delivered in cassette units, work efficiency is improved, and a reduction in yield due to conventional handling errors can be prevented. For this reason, productivity can be improved.

According to the semiconductor wafer transfer device of the vertical furnace according to the second aspect of the present invention, the positioning plates are brought into contact with each other to prevent the comb-teeth loader from directly applying a force to the semiconductor wafer. Further, the transfer yield can be further improved by preventing the semiconductor wafer from being damaged.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of a semiconductor wafer transfer device of a vertical furnace according to one embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

3A and 3B are diagrams illustrating an operation of transferring a semiconductor wafer from a cassette to a boat, wherein FIG. 3A illustrates a state where the semiconductor wafer is supported by the cassette, and FIG. 3B illustrates a state where the semiconductor wafer is supported by a comb-shaped loader.

[Explanation of symbols]

 Reference Signs List 1 boat 12 wafer support 2 cassette 21 support shelf 21a space 22 rear opening 23 front 3 boat elevating means 4 cassette support 5 cassette elevating means 6 push mechanism 61 comb-shaped loader 61b loader positioning plate 7 receive mechanism 71 comb teeth Loader 71b Loader positioning plate A Semiconductor wafer R Vertical furnace

Claims (2)

[Claims] 1. A vertical furnace semiconductor wafer transfer apparatus for performing heat treatment in a state in which a plurality of semiconductor wafers are held in multiple stages with a gap provided therebetween by a wafer support portion of a boat,
A support shelf that supports semiconductor wafers configured in multiple stages at the same interval as the wafer support portion, the support shelf is divided into left and right, a cassette provided with a space in the middle, and the cassette in the boat A first cassette supporter for holding the cassette in opposition to the first supporter, the first supporter having projections arranged at the same interval as the wafer supporter;
In a state in which the projections are inserted between a plurality of semiconductor wafers, the semiconductor wafers are provided for delivery of the semiconductor wafers, and a space between the original position and the boat is passed through the space of the cassette. A push mechanism for horizontally moving the first comb tooth loader, and a second comb tooth loader having the same shape as the first comb tooth loader, and a projection of the second comb tooth loader. The first part
In a state in which a plurality of semiconductor wafers are inserted between the projections of the comb-shaped loader in a direction opposite to that of the projections, the semiconductor wafers are delivered and held at a constant distance from each other in conjunction with the push mechanism. A receiving mechanism for horizontally moving the second comb-shaped loader while transferring the semiconductor wafer between the protrusion and the support shelf by moving the cassette support up and down; A vertical furnace provided at a lower portion of the boat, and comprising: a boat elevating means for transferring a semiconductor wafer between the protrusion and the wafer support part by elevating the boat. Semiconductor wafer transfer device. 2. The first comb-shaped loader and the second comb-shaped loader each have a loader positioning plate which is opposed to each other in a horizontal direction, and the positioning plates are brought into contact with each other. 2. The semiconductor wafer transfer device according to claim 1, wherein said constant interval is maintained.