JPH11145268A - Carrier for semiconductor wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deformation of a carrier in an upper part and a lower part caused by a wafer and improve washing effect of a wafer by forming a rib for reinforcement in a lower end part of a carrier body at a specified interval and forming a flange part to a double structure in a carrier body. SOLUTION: A carrier body 10a has four sidewalls 12, 13, 14, 15 and a wafer containing part 16 is formed between them. A rib 18 for reinforcement is formed in a bottom part of the carrier body 10a parallel to a wafer to be contained, A flange part 30 which is loaded most when lifted by a carrier transfer device is formed to a double structure of an inner flange part 31 and an outer flange part 32. Therefore, deformation can be prevented. Accordingly, carrier is not deformed when loaded by a wafer and treated at a high temperature, and damage, etc., of a wafer caused by deformation of a carrier can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a particularly large semiconductor wafer, for example, having an outer diameter of 12 inches (about 300 mm).
And a semiconductor wafer carrier suitable for housing and transporting a large-diameter semiconductor wafer.

[0002]

2. Description of the Related Art Conventionally, ICs (integrated circuits), LSIs
In the manufacturing process of a (large-scale integrated circuit), since semiconductor wafers such as silicon wafers are extremely reluctant to contaminate, a plurality of semiconductor wafers are housed in a semiconductor wafer carrier (hereinafter simply referred to as “carrier”). After being transported in a state of being isolated from the surroundings, various processes such as cleaning with a chemical solution, cleaning with pure water, and drying are performed.

[0003] As described above, since the carrier has conventionally been required to be immersed in various chemicals to perform various treatments on the wafer, PT is a fluororesin having good chemical resistance and high temperature resistance.
It is formed by cutting FE (polytetrafluoroethylene) or by injection molding PFA (polytetrafluoroethylene-perfluoroalkylvinyl ether copolymer).

As shown in FIGS. 3 and 4, such a carrier has two side walls 2 and 2 on which a carrier body 1 faces each other, and a pair of connecting walls 3 and 3 for connecting them. The center is formed with a large opening so as to be easily immersed in a chemical solution. Further, the carrier body 1 has a plurality of wafer separating ribs 5 protruding inward so that grooves 4 having a predetermined width are formed in the inner surfaces 2a of both side walls 2, 2.
The ribs 5 separate the wafers W from each other at a fixed interval, and hold them independently. Two legs 6, 6 provided with a rib 5 for separating the wafer are also provided on the bottom, and are mounted on a mounting table 7 or the like by the legs 6, 6. When the wafer W is transported using the carrier body 1, the upper flange 8 projecting outward from the upper ends of the side walls 2, 2 in the state shown in FIG. The carrier 9 is conveyed by holding the carrier body 1 with the gripping portion 9a of the carrier conveying device 9 locked from below.

As shown in FIG. 5, a conventional wafer carrier for accommodating a large semiconductor wafer W has two legs 6, 6 having a rib 5 for separating a wafer, and Generally, the peripheral edge of the wafer W is supported at four points, namely, both side walls 2 and 2 provided with ribs 5 for use.

[0006]

By the way, most semiconductor wafers have an outer diameter of 6 inches (approximately φ150 mm) to 8 inches (approximately φ200 mm). Large-diameter semiconductor wafers have begun to appear on the market, and carriers used for transporting the semiconductor wafers need to be increased in size accordingly. Also, in the current 8-inch carrier, conventionally, 25 to 26 wafers were generally accommodated, but in order to increase the number of processed wafers in response to mass production, the number of wafers has to be doubled. That is, there is an increasing demand for processing 50 to 52 wafers at a time.

However, when using a carrier having a conventional structure as shown in FIG. 3 to transport about 50 large semiconductor wafers W of about 12 inches, the material constituting the carrier body 1 is made of PTFE or PTFE. Since it is a fluororesin such as PFA, the strength becomes weak relative to the weight of the wafer W. As a result, the vicinity of the upper flange 8 at the upper end of the carrier side walls 2 and 2 is deformed in the direction A, and the dimensional accuracy is reduced. Of the carrier body 1 may fall from the holding portion 9a of the carrier transfer device 9 to damage the wafer W.

Further, even if the leg 6 of the carrier body 1 is present, the load of the wafer W directly acts on the upper portion thereof, so that the carrier may be deformed in the direction of arrow B. If such deformation is repeated, permanent deformation occurs, and the performance of the carrier is deteriorated. The dimensional accuracy required for the carrier to stably hold the wafer is deteriorated, and trouble occurs in wafer transfer, automatic transport of the carrier itself, and the like. For example, adjacent wafers W come into contact with each other, causing damage to the wafers W, which is not preferable.

[0009] Such a problem is caused, in particular, as the number of wafers W accommodated in the carrier is large and the weight of the wafer W transferred by the carrier is increased, and the carrier is used in a high temperature region such as 130 ° C to 160 ° C. It is remarkable when you do.

[0010] In order to solve such a problem, PEEs are provided on both side walls 2 and 2 of the carrier body 1 or the legs 6.
2. Description of the Related Art Strengthening is performed by inserting a reinforcing member such as K (polyetheretherketone), metal, or quartz. However, in this case, it is necessary to insert a reinforcing member into the carrier body 1, and it is technically difficult to form an integral structure by injection molding. Also, in the case of a carrier made of PEEK, it cannot withstand sulfuric acid and nitric acid,
A quartz carrier cannot withstand hydrofluoric acid, and has a problem that the used chemical solution is limited.

When a carrier is molded by injection molding or the like, a certain molding distortion is inevitably generated. Therefore, as shown in FIG. 5, the entire wafer is supported at four points with two legs. When such a carrier is molded, there is a problem that a high degree of control is required at the molding stage in order to manufacture a carrier satisfying all four dimensional accuracy.

In view of such circumstances, the present invention, when accommodating a large-diameter semiconductor wafer and performing chemical treatment, prevents deformation of the upper and lower portions of the carrier due to the wafer and cleans the wafer irrespective of the chemical used. It is an object of the present invention to provide a fluororesin semiconductor wafer carrier that can improve the cleaning effect at the time of cleaning and can be easily formed.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in order to achieve the above-mentioned problems and objects in the prior art, and has four side walls which define a receiving portion for a semiconductor wafer. A wafer separating rib for accommodating a plurality of semiconductor wafers at predetermined intervals is provided on inner surfaces of a pair of side walls facing each other of the carrier body, and the carrier body is provided at least on upper ends of the pair of side walls. A carrier for a semiconductor wafer, comprising a flange portion capable of being locked by a carrier transport device for transporting while holding, and a leg portion capable of holding a self-standing posture formed at a bottom portion of the carrier body. Wherein a reinforcing rib is formed at a predetermined interval at a lower end portion of the carrier body.

According to the present invention having such a configuration, the strength of the leg portion is increased, the outward deformation can be prevented, and the immersion of the chemical solution can be performed effectively.

In the present invention, the flange portion formed on the carrier main body is constituted by an outer flange portion and an inner flange portion. With such a configuration, it is possible to prevent the main part from being deformed by the load of the wafer or the like when lifted from the flange part.

In the present invention, instead of the rib for separating the wafer which is usually formed on the upper surface of the two legs, the rib is located at substantially the center of the two legs, and one rib is provided in parallel with the legs. By providing a rib for separating the wafer on its upper surface, the wafer can be divided into three ribs by the separating rib on both side walls and the separating rib.
It is characterized by being supported by points.

Thus, the dimensional accuracy for molding the carrier body can be reduced as compared with the case where the carrier is supported at four points. In addition, with this configuration, even when a large-diameter semiconductor wafer is transported in a stored state, the carrier is not deformed, and it is possible to perform various kinds of processing such as chemical cleaning, pure water cleaning, and drying. Becomes

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a first embodiment of the semiconductor wafer carrier of the present invention, and FIG.
FIG. 2 is a sectional view taken along line II-II of FIG.

In FIG. 1, reference numeral 10 denotes a semiconductor wafer carrier (hereinafter simply referred to as “wafer carrier”) of the present invention.
Is shown). This wafer carrier 10 is
A plurality of semiconductor wafers W such as silicon wafers are accommodated in a carrier body 10a, and are used for transportation and processing in order to perform various kinds of processing such as chemical cleaning, pure water cleaning, and drying. The present invention is applied to a larger semiconductor wafer having a large diameter of, for example, 12 inches (about φ300 mm).

The general shape of the wafer carrier 10 is determined by the shape of the wafer W. In the present embodiment, the wafer carrier 10 is used for a disk-shaped wafer W, and the carrier body 10a has a vertical cylindrical shape. The shape is cut in the direction, and the cross section has a substantially arc shape.

The carrier body 10a of the wafer carrier 10 is made of, for example, PT
It is made of a fluororesin such as FE (polytetrafluoroethylene) and PFA (polytetrafluoroethylene-perfluoroalkylvinyl ether copolymer), and is formed by injection molding, cutting, or assembling.

The carrier body 10a has four side walls 12, 1
3, 14, and 15, and the wafer storage unit 1
6 are formed. The bottom of the carrier body 10a is formed with legs 25 formed in parallel with the wafer in which the reinforcing ribs 18 are accommodated and capable of maintaining its own self-standing posture. The leg 25 is composed of three ribs: ribs 17 at both ends and a rib 17 ′ newly formed at the center. Each of the side walls 12, 13, 14, 15 has a large-area opening.

The opening of each side wall and the reinforcing rib 1
The openings formed in a lattice pattern between the ribs 8 and the leg ribs 17, 17 ′, 17 are provided in the carrier tank 10 a, for example, in a chemical tank filled with a chemical for the purpose of performing various processes on the wafer W. When the wafer W is immersed in the wafer W, the chemical liquid penetrates into the wafer accommodating portion 16 through these openings to efficiently process the wafer W.

Also, grooves 19 and 20 having a predetermined width are formed at the upper ends of the pair of opposed side walls 12 and 14, respectively.
A plurality of wafer separating ribs 21 and 22 are protruded. That is, usually, the legs of the carrier (ribs 17, 1
A plurality of wafer separating ribs are formed on the upper surface of 7).
In the present embodiment, this is eliminated and the rib 1 formed in the center is removed.
A new rib for wafer separation protrudes from the upper surface of 7 '.

Therefore, in the wafer carrier 10, the wafers W are separated from each other by a predetermined distance by the ribs 21, 22, and 27 formed at these three locations, and can be held independently. That is, the wafer W is supported in three grooves formed on the side walls 12 and 14 and the rib 17 ′ provided on the lowermost leg 25.

As described above, according to the present embodiment, the wafer W
Are supported at three points, as compared with the case where the wafer W is supported at four points as in the case of FIG. 5, the tolerance for the dimensional change at the time of formation is increased, and the difficulty in manufacturing is reduced.
It is possible to produce a carrier that supports a wafer reliably with good yield.

On the other hand, the upper ends of the side walls 13 and 15 are provided with horizontally wide flange portions 30 and 30, respectively. The flange portion 30 has an inner flange portion 31
And an outer flange portion 32 to form a double structure, and a liquid communication hole 33 is formed in the connection portion.

At the upper ends of the side walls 12 and 14, side walls 34 and 35 are disposed to hang downward so as to surround the periphery thereof.
2, 14 are longitudinal ribs 36 arranged at predetermined intervals,
At 37 they are connected to each other.

As described above, on the side walls 12 and 14,
The bent upper ends of the walls 12 and 13 constitute an inner flange portion, and the walls 34 and 35 constitute an outer flange portion.

Further, on the lower surfaces of the vertical ribs 36 and 37 connected to the walls 34 and 35, gripping portions 3 of the carrier transport device are provided.
Locking recesses 39 and 40 are formed so that the locks 7 and 38 can be locked. Thus, the carrier 10 can be transported while holding the carrier body 10a.

In this embodiment, the positions where the locking concave portions 39 and 40 are provided are in the vicinity of the walls 34 and 35 in the present embodiment, but are not limited to this. In addition, the holding part of the carrier transport device is locked in the locking recesses 39 and 40,
Since the carrier main body 10a containing the wafer W is lifted and transported to the next step, such as a chemical tank, and immersed in the chemical tank together with the carrier main body 10a,
It is necessary to have chemical resistance and strength not to be deformed even under the load of the wafer W. Therefore, for example, metal such as SUS304 or PEEK or the like as a core, chemical resistance,
It is preferable to coat with a high temperature resistant fluororesin or the like.

According to the present embodiment, the carrier transport device 50
When the carrier body 10a is lifted by the grip portion 37, the load can be received by the walls 34, 35 via the vertical ribs 36, 37. That is, the load such as the wafer W can be received by the outer flange portion 32. Therefore, since a force acts on the inner flange portion 31 constituting the main portion of the carrier body 10a, the deformation of the inner flange portion 31 can be prevented.

Further, since a plurality of reinforcing ribs 18 are formed on the bottom of the carrier body 10a, the bottom does not expand outward even when the carrier is taken out of the chemical solution tank, for example. . In addition, even when immersing in a chemical solution, since the openings are formed between the ribs, there is no hindrance to the immersion in the chemical solution.

As described above, according to this embodiment, even if the wafer carrier accommodates a large number of large-diameter wafers,
Either part is not deformed, and the chemical treatment can be performed effectively.

In the above embodiment, the so-called low profile type carrier main body 10a for accommodating the lower half of the wafer W has been described. However, the present invention accommodates the entire wafer W as shown in FIG. It goes without saying that the present invention can be applied to a high profile type carrier body.

In the above embodiment, the carrier body 10
The flange portion 30a is composed of the outer flange portion 32 and the inner flange portion 31, and the reinforcing ribs 18 are formed. However, sufficient strength can be obtained by forming the flange portion 30 twice. If obtained, the ribs 18 for reinforcement may not be provided. Conversely, ribs 18 for reinforcement
If sufficient strength can be obtained by providing, the flange portion does not need to be formed twice.

Needless to say, as shown in the above embodiment, the strength is improved by doubling the flange portion and providing the reinforcing ribs 18.

[0038]

As described above, according to the present invention,
Since the reinforcing ribs are formed between the side walls, the bottom does not expand due to the load of the wafer. Therefore, the carrier is hardly deformed even when the wafer carrier is lifted, so that the carrier is not deformed even when storing and transporting a semiconductor wafer having a large diameter, for example, an outer diameter of 12 inches (about φ300 mm). It is possible to carry out processes such as various chemical cleaning, pure cleaning, and drying.

Further, when the carrier is lifted by the carrier transport device, the flange portion to which the most load is applied is formed double, so that deformation can be prevented. Further, in holding the semiconductor wafer, one wafer is held at three places, so that the structure of the carrier body can be simplified.

As described above, according to the present invention, the carrier is not deformed even under the load of the wafer or when the wafer is processed at a high temperature, so that the damage of the wafer due to the deformation of the carrier is prevented. Does not occur.

[Brief description of the drawings]

FIG. 1 is a plan view of one embodiment of a semiconductor wafer carrier of the present invention.

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

FIG. 3 is a cross-sectional view of a conventional semiconductor wafer carrier.

FIG. 4 is a bottom view of a conventional semiconductor wafer carrier.

FIG. 5 is a cross-sectional view of another conventional semiconductor wafer.

[Explanation of symbols]

 10 Wafer carrier 10a Carrier body 12, 13, 14, 15 ... Side wall 16 ... Housing 18 ... Reinforcing ribs 21, 22, 27 ... Rib for wafer separation 25 ... Leg 30 ... Flange 31 ... Inner flange 32 ... Outer flange 50 ... Carrier transport device W ...・ Wafer

Claims (4)

[Claims] 1. A wafer separating device for accommodating a plurality of semiconductor wafers at predetermined intervals on inner surfaces of a pair of opposed side walls of a carrier body having four side walls defining a semiconductor wafer accommodating portion. With a rib, a carrier transporting device for holding and transporting the carrier body at least at an upper end portion of the pair of side walls is provided with a flange portion that can be locked, and further at a bottom portion of the carrier body,
A semiconductor wafer carrier in which legs capable of maintaining a self-standing posture are formed, wherein reinforcing ribs are formed at predetermined intervals at a lower end of the carrier body. Wafer carrier. 2. The carrier for a semiconductor wafer according to claim 1, wherein a lower end of the carrier body having four side walls defining a receiving portion of the semiconductor wafer is supported at three points. . 3. A wafer separating device for accommodating a plurality of semiconductor wafers at predetermined intervals on inner surfaces of a pair of opposed side walls of a carrier body having four side walls defining a semiconductor wafer accommodating portion. With a rib, a carrier transporting device for holding and transporting the carrier body at least at an upper end portion of the pair of side walls is provided with a flange portion that can be locked, and further at a bottom portion of the carrier body,
A semiconductor wafer carrier on which a leg capable of maintaining a self-standing posture is formed, wherein the flange formed on the carrier main body includes an outer flange portion and an inner flange portion. Characteristic carrier for semiconductor wafers. 4. The semiconductor wafer carrier according to claim 3, wherein a lower end portion of the carrier body having four side walls defining a receiving portion of the semiconductor wafer is supported at three points. .