JPH08288377A - Wafer container - Google Patents

Abstract

PURPOSE: To provide a wafer container, as a wafer transferring cassette or case, that does not emit gas and does not contaminate stored wafers. CONSTITUTION: The wafer container, as a wafer transferring cassette 20 and storing case 26, comprises polybutylene terephthalate resin. The container comprises liquid crystal polymer made from the material as paraoxy-benzoic acid and terephthaloyl. Organic compound as the out gas from the container is minimized and the organic contamination of the wafer is prevented by composing it with such a material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer container which can be safely transported, stored or stored without contaminating a semiconductor wafer.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, a wafer is generally housed in a wafer housing such as a carrying cassette or a case and moved between processes. Conventionally, the wafer container is made of resin such as polyethylene, polypropylene or polycarbonate. In order to prevent the contamination of the wafer inside the wafer container,
The environment is free of dust.

[0003]

However, with the increase in the density and the degree of integration of the devices formed on the semiconductor wafer, not only dust but also the organic contamination by the outgas from the container has an adverse effect. It was

According to a new finding of the present inventor, a plasticizer contained in a wafer container made of synthetic resin such as polyethylene, polypropylene or polycarbonate,
A large amount of additives such as an antioxidant, an ultraviolet absorber or a cross-linking agent is released as outgas and is adsorbed on the wafer being stored.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wafer container such as a wafer transfer cassette or case in which outgas is hardly generated and a stored wafer is not contaminated. And

[0006]

In order to achieve the above object, the wafer container according to the first aspect of the present invention is characterized by being made of a resin containing polybutylene terephthalate as a main component. The content of the additive contained in the resin containing polybutylene terephthalate as a main component constituting the wafer container is 1500 ppm or less and 500 pp or less.
It is preferably m or more, and preferably 1000 ppm or less. The upper limit of the content of the additive is determined from the viewpoint of preventing contamination of the wafer by the outgas of the additive.
The lower limit of the additive is determined from the viewpoint of resin moldability.
The smaller the content of the additive is, the more preferable as long as the resin can be molded and has required strength, durability and weather resistance.

A wafer container according to a second aspect of the present invention is characterized by being composed of a resin containing a liquid crystal polymer as a main component. The raw material of the liquid crystal polymer is preferably any one of paraoxybenzoic acid and terephthaloyl.

The content of the additive contained in the resin containing the liquid crystal polymer as a main component which constitutes the wafer container is
1,500 ppm or less, 500 ppm or more, preferably 10
It is preferably 00 ppm or less. The upper limit of the content of the additive is determined from the viewpoint of preventing contamination of the wafer by the outgas of the additive. The lower limit of the additive is determined from the viewpoint of resin moldability. The smaller the content of the additive is, the more preferable as long as the resin can be molded and has required strength, durability and weather resistance. In the present invention, the wafer container conveys the wafer,
The case is used for storage, storage, or other handling, and its name, shape, and structure are not particularly limited, and include a wafer transfer cassette, a storage case, and the like.

In the present invention, the additive is an antioxidant necessary for molding a wafer container with a synthetic resin,
It is a plasticizer, a crosslinking agent, or an ultraviolet absorber.

[0010]

The wafer container according to the first aspect of the present invention is
It is composed of a resin containing polybutylene terephthalate as a main component (polybutylene terephthalate resin). When molding a wafer container with polybutylene terephthalate resin, due to its excellent moldability, it requires only a small amount of plasticizer, and due to its excellent weather resistance, the amount of antioxidant and ultraviolet absorber is small. Complete. Therefore, the amount of outgas released from the wafer container made of polybutylene terephthalate resin is small.

Therefore, by using the wafer container according to the first aspect of the present invention, it is possible to effectively prevent the adsorption of organic substances on the surface of the wafer when the wafer is transported, stored, stored, or otherwise handled. . In addition, the wafer container according to the first aspect of the present invention can be manufactured at a low cost, which is a fraction of that of a polycarbonate resin, and compared with a fluororesin such as PTFE or PFA. It is about 30% lighter. Furthermore, since the wafer container according to the first aspect of the present invention is made of polybutylene terephthalate resin, it has excellent antistatic performance.

A wafer container according to a second aspect of the present invention is a resin containing a liquid crystal polymer as a main component (liquid crystal polymer).
Composed of. Since the liquid crystal polymer contains a self-reinforcing fiber orientation component in its molded product, the compounding amount of additives such as a crosslinking agent and an antioxidant can be reduced. for that reason,
The amount of outgas emitted from the wafer container made of liquid crystal polymer is small.

Therefore, by using the wafer container according to the second aspect of the present invention, organic substances can be effectively prevented from being adsorbed on the surface of the wafer when the wafer is transported, stored, stored, or otherwise handled. . The wafer container according to the second aspect of the present invention is about 30% lighter than fluororesins such as PTFE and PFA.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The wafer container according to the present invention will be described in detail below with reference to the embodiments shown in the drawings. Embodiment 1 A wafer container according to the embodiment shown in FIG. 1A is a wafer transfer cassette 20 and has an accommodation groove 24 for accommodating a large number of semiconductor wafers 22. In this embodiment, this wafer transfer cassette 20 is molded from polybutylene terephthalate resin. The cassette 20 composed of polybutylene terephthalate resin was molded by injection molding, and the additive contained in the resin was only the antioxidant, and the content thereof was 1000 ppm.

The wafer storage body according to the embodiment shown in FIG. 1B is a wafer storage case 26, and its case 2
A cassette 20 in which the wafer 22 shown in FIG. In this embodiment,
The storage case 26 was molded from polybutylene terephthalate resin. The storage case 26 made of polybutylene terephthalate resin was molded by injection molding, and the additive contained in the resin was only the antioxidant, and the content thereof was 1000 ppm.

A portion of the cassette 20 shown in FIG. 1 (A) or the storage case shown in FIG. 1 (B) is cut out into a fixed quantity and a fixed shape to prepare a sample, and the sample is prepared as a Curie point headspace. Gas chromatography·
Infrared spectroscope / Mass spectroscope (CuriePoint-
Headspace-GC / IR / MS).

This apparatus has a Curie point headspace sampler 1 and a sample 2 is a sample tube 3
The inside of the sample tube 3 is housed inside and is heated by the sample heater 4. In this embodiment,
Sample 2 is heated to 100 ° C. He gas is introduced into the sample tube 3 as a carrier gas.

A concentrator 5 is connected to the lower part of the sample tube 3. The concentrating device 5 has a trap tube 7 and a pyrolyzer 6. A needle heater 8, a gas chromatograph 9, an infrared spectroscope 10 are provided below the trap tube 7.
And the mass spectrometer 11 is sequentially connected.

Using the apparatus shown in FIG. 2, a qualitative analysis of outgas from sample 2 made from a part of the cassette 20 shown in FIG. 1A or the storage case shown in FIG. I went. The results are shown in the PBT column in Table 1.

[0020]

[Table 1]

As shown in Table 1, none of the organic compounds shown in Table 1 was detected in the outgas of the cassette or storage case made of PBT. Since the organic compounds shown in Table 1 generally have a low vapor pressure and have polar groups, they are easily adsorbed on the surface of a semiconductor wafer, which adversely affects device characteristics. In this example, these organic compounds were not detected in the outgas of the cassette or the storage case made of PBT.

Embodiment 2 Cassette 20 and storage case 26 shown in FIG. 1 (A)
Was molded with a liquid crystal polymer using paraoxybenzoic acid as a raw material, and the cassette 20 shown in FIG. 1 (A) or FIG. Sample 2 created from a part of the storage case shown in
A qualitative analysis of the outgasses from and relative comparison of the amounts was performed.

The results are shown in the column of LCP in Table 2.

[0024]

[Table 2]

As shown in Table 2, none of the organic compounds shown in Table 2 was detected in the outgas of the cassette or the storage case composed of the liquid crystal polymer made of paraoxybenzoic acid as a raw material. Since the organic compounds shown in Table 2 generally have a low vapor pressure and have polar groups, they are easily adsorbed on the surface of the semiconductor wafer, which adversely affects the device characteristics. In this example, these organic compounds were not detected in the outgas of the cassette or the storage case made of the liquid crystal polymer made of paraoxybenzoic acid as a raw material. Third Embodiment Cassette 20 and storage case 26 shown in FIG.
Was molded from a liquid crystal polymer using terephthaloyl as a raw material, and the apparatus shown in FIG. 2 was used in the same manner as in Example 1 to show the cassette 20 shown in FIG. 1 (A) or the cassette 20 shown in FIG. Sample 2 created from a part of the storage case
A qualitative analysis of the outgasses from and relative comparison of the amounts was performed.

The results are shown in the LCP column in Table 2 above.
As shown in Table 2, none of the organic compounds shown in Table 2 was detected in the outgas of the cassette or the storage case made of the liquid crystal polymer using terephthaloyl as a raw material.

Since the organic compounds shown in Table 2 generally have a low vapor pressure and have polar groups, they are easily adsorbed on the surface of the semiconductor wafer, which adversely affects the device characteristics. In this example, these organic compounds were not detected in the outgas of the cassette or the storage case composed of the liquid crystal polymer made of terephthaloyl as a raw material. Comparative Example 1 Cassette 20 and storage case 26 shown in FIG.
2 was used in the same manner as in Example 1 except that polyethylene was molded from the cassette 20 shown in FIG. 1 (A) or a part of the storage case shown in FIG. 1 (B). A qualitative analysis of the outgas from the prepared sample 2 and a relative comparison of amounts were performed.

The results are shown in the PE column of Tables 1 and 2 above. As shown in Tables 1 and 2, large amounts of various phthalate ester plasticizers were detected. Comparative Example 2 Cassette 20 and storage case 26 shown in FIG.
2 was used in the same manner as in Example 1 except that the above was molded from polypropylene by using the apparatus shown in FIG. 2 from a part of the cassette 20 shown in FIG. 1A or the storage case shown in FIG. A qualitative analysis of the outgas from the prepared sample 2 and a relative comparison of amounts were performed.

The results are shown in the PP column of Tables 1 and 2 above. As shown in Tables 1 and 2, a large amount of various phthalate ester plasticizers, phenolic antioxidants and organic peroxide crosslinking agents were detected. Comparative Example 3 Cassette 20 and storage case 26 shown in FIG.
Example 1 except that was molded with polycarbonate.
Similarly to the above, using the apparatus shown in FIG. 2, a qualitative analysis of the outgas from the sample 20 prepared from the cassette 20 shown in FIG. 1A or a part of the storage case shown in FIG. A relative comparison was made.

The results are shown in the columns of PC in Tables 1 and 2 above. As shown in Tables 1 and 2, large amounts of various phthalate ester plasticizers were detected. Comparing Evaluation Examples 1 to 3 with Comparative Examples 1 to 3, in Comparative Example, organic compounds were detected from the outgas of the cassette or the storage case, as shown in Tables 1 and 2, whereas In the examples, none of the organic compounds shown in Tables 1 and 2 was detected in the outgas of the cassette or the storage case.

Since the organic compounds shown in Tables 1 and 2 generally have a low vapor pressure and have polar groups, they are easily adsorbed on the surface of the semiconductor wafer, which adversely affects the device characteristics. Therefore, when the wafer is stored in the wafer transport cassette and the storage case according to the comparative example, there is a possibility that the organic compound may cause contamination.

On the other hand, in this example, these organic compounds were not detected in the outgas of the cassette or the storage case. Therefore, the container such as the wafer transfer cassette and the storage case according to the present embodiment is
Semiconductor wafers are less likely to be contaminated with organic compounds and can be safely transported or stored.

The present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the present invention. For example, the wafer container according to the present invention is not limited to the shape or structure of the above embodiment.

[0034]

As described above, according to the present invention, it is possible to effectively prevent the adsorption of organic substances on the surface of a wafer when the wafer is transported, stored, stored, or otherwise handled.

In addition to the above effects, a wafer container made of polybutylene terephthalate resin can be manufactured at a low cost of a fraction of that of a polycarbonate resin, and fluorine such as PTFE and PFA can be manufactured. It is about 30% lighter than resin. Further, since this wafer container is made of polybutylene terephthalate resin, it has excellent antistatic performance.

In addition to the above effects, the wafer container made of liquid crystal polymer is also about 30% lighter in weight than fluororesins such as PTFE and PFA.

[Brief description of drawings]

1A is a partially omitted perspective view of a wafer transfer cassette according to an embodiment of the present invention, and FIG. 1B is a perspective view of a storage case according to another embodiment of the present invention. is there.

FIG. 2 is a schematic diagram of an analyzer used in the analysis of Examples and Comparative Examples of the present invention.

[Explanation of symbols]

 20 ... Wafer carrying cassette 22 ... Wafer 24 ... Storage groove 26 ... Storage case

Claims (5)

[Claims] 1. A wafer container used for handling a wafer, which is made of a resin containing polybutylene terephthalate as a main component. 2. The wafer container according to claim 1, wherein the content of the additive contained in the resin containing polybutylene terephthalate as a main component constituting the wafer container is 1500 ppm or less and 500 ppm or more. 3. A wafer container used for handling a wafer, which is made of a resin containing a liquid crystal polymer as a main component. 4. The wafer container according to claim 3, wherein the raw material of the liquid crystal polymer is one of paraoxybenzoic acid and terephthaloyl. 5. The wafer container according to claim 3, wherein the content of the additive contained in the resin containing a liquid crystal polymer as a main component that constitutes the wafer container is 1500 ppm or less and 500 ppm or more.