TW201701391A - A cycloolefin composition and a cycloolefin semiconductor substrate transport box made of the same - Google Patents

Abstract

The present invention provides a cycloolefin composition. The cycloolefin composition comprises cycloolefin copolymer (COC) or cycloolefin polymer (COP), and carbon nanotubes, wherein the content of the carbon nanotubes ranges from 1% to 5% by weight. The present invention also provides a cycloolefin semiconductor substrate transport box, wherein the cycloolefin semiconductor substrate transport box is made of the cycloolefin composition.

Description

Cyclic olefin composition and cycloolefin semiconductor substrate transfer box using the same

The present invention relates to a material composition and its use, and more particularly to a composition comprising a cycloolefin compound having a carbon nanotube as a main component and an application thereof.

In the semiconductor industry, it is commonly used as a substrate transfer box, a wafer cassette or a photomask box. The main materials of the carrier or the box are: polypropylene (PP), polycarbonate (PC), and liquid crystal polymer. (Liquid Crystal Polymer; LCP).

Most of the early transfer boxes were made of PP as the main material, but they were used less because of their low manufacturing yield. Later, PCs were used as the main material, but the water absorption rate of the material itself was more than 0.25%, and the low humidity maintenance time was low. Short, the demand for maintaining the drying process is higher than that of the process, which will increase the manufacturing cost and is therefore less used.

However, LCP is generally considered to have the advantages of high hardness, high heat distortion temperature, high yield, and long humidity maintenance time, which is superior to the other two. However, there are still other problems, such as high material cost, weak vertical direction and easy fracture.

Therefore, in the face of the strict process standards and cost considerations of the semiconductor industry, the choice of the main material is crucial in the case of not changing the main structure of the carrier or the box. It is one of the problems to be solved by the present invention to improve the quality of single materials, to achieve high quality, high dimensional stability, impact resistance, long humidity maintenance time, low harmful gas release, and low organic gas volatilization.

The invention selects a cycloolefin composition as the main material of the semiconductor substrate transfer box, and achieves the above-mentioned strict requirements at one time, and through a plurality of tests and researches, selects the ratio of the excellent additive which best meets the actual process requirements for the industry. reference.

The present invention provides a cyclic olefin composition comprising a cyclic olefin compound and further comprising a carbon nanotube such that the weight percentage of the carbon nanotube is from 1% to 5%.

The cycloolefin compound may be a cycloolefin copolymer (COC) or a cycloolefin polymer (COP).

A cyclic olefin compound is a material having low hygroscopicity, high chemical resistance, and good mechanical strength. It can be divided into three types: elastomer, thermosetting plastic and thermoplastic plastic, among which thermoplastics can also have high transparency.

The method for producing a cycloolefin compound is a ring-type exchange polymerization method (ROMP), a reaction-molded thermosetting copolymer, and a thermoplastic copolymer having a molecular weight controlled by a hydrogenation step, that is, COC. The other is to carry out a polymerization reaction in the presence of a catalyst to maintain a bicyclic structure in the main chain, that is, a cyclic olefin polymer COP.

The invention further adds a cycloolefin compound to the carbon nanotubes of 1% to 5% by weight to further add conductive or static dissipative properties or to change the toughness structure, so that the cycloolefin composition formed by the cycloolefin compound has a wider application range and is more capable. Meet the needs of semiconductor processes.

The cycloolefin semiconductor substrate transfer cassette of the present invention is made of the above-mentioned cyclic olefin composition, and has the advantages of light weight, high dimensional stability, impact resistance, long humidity maintenance time, low harmful gas release, high yield, and the like. characteristic.

The cycloolefin composition and the cycloolefin semiconductor substrate transfer cassette using the same have a development advantage as compared with the transfer box using PP, PC or LCP as the main material.

Figure 1 is a diagram of the release test of harmful ions; Figure 2 is a plot of dimensional stability test; and Figure 3 is a plot of relative humidity test.

The cycloolefin composition of the present invention means a cycloolefin compound such as a cycloolefin copolymer (COC) or a cycloolefin polymer (COP) as a host material, and the weight percentage is 1%~ A composition formed of a 5% carbon nanotube, and a cycloolefin semiconductor substrate transfer case produced using the composition of the material.

In this embodiment, a front opening unified pod (FOUP) made of a carbon nanotube with a weight percentage of 1% to 5% by weight is used as an example, and various characteristics are actually measured. And the cycloolefin composition and the cycloolefin semiconductor substrate transfer cassette of the present invention can be further confirmed as compared with the previously opened wafer cassette which is also a cyclic olefin compound and a carbon fiber to replace the carbon nanotubes and the LCP. The excellent characteristics and scope of application.

First, please refer to Figure 1, which is a diagram of the release test of harmful ions, which is made by using an ion chromatograph to add 1% to 5% by weight of carbon nanotubes, COC plus carbon fiber, and LCP. The ion release concentration was tested in a previously opened wafer cassette. In Fig. 1, the vertical axis represents the release concentration of harmful ions (unit: one part per billion; ppb); the horizontal axis represents various harmful ions, including fluoride ion (F ^- ), chloride ion (Cl ^- ), sub Nitrate ion (NO ₂ ^2- ), bromide ion (Br ^- ), nitrate ion (NO ₃ ^- ), sulfate ion (SO ₄ ^2- ), lithium ion (Li ⁺ ), ammonium ion (NH ₄ ⁺ ), potassium ion (K ⁺ ), magnesium ion (Mg ²⁺ ), and calcium ion (Ca ²⁺ ).

It can be seen from the test results that before the COP is added with a weight percentage of 1% to 5% of the carbon nanotubes, the open wafer cassette has a low release amount of harmful ions, and is similar to the cyclic olefins. The COC of the compound is added to the previously opened wafer cassette made of carbon fiber or LCP material, and the addition of the carbon nanotubes is more beneficial to reduce the amount of harmful ions released in various processes.

Please refer to Figure 2, which is a dimensional stability test chart. It is a previously opened wafer cassette made of COP with 1% to 5% by weight of carbon nanotubes, COC added carbon fiber and LCP. experimenting. Due to the shrinkage of the plastics during the molding of the previously opened wafer cassettes, there may be a difference in size between the front open wafer cassettes, so that they are placed in the front open wafer cassette. The distance from the first to the 25th wafers to the standard position can be used to measure the offset position of each wafer. If the offset position is predictable, indicating that the plastic shrinkage direction is predictable, it will be easy to adjust and improve the process conditions, which can improve the dimensional stability of the front open wafer cassette, thereby improving the product yield.

The test results in Figure 2 show that the COP added 1%~5% carbon nanotubes or the COC-added carbon fiber front-opening wafer cassette, the test results are better than those produced by LCP. The wafer cassette is more linear and predictable. Therefore, the use of a cycloolefin compound to add a 1% to 5% by weight carbon nanotube or carbon fiber front-opening wafer cassette can help improve process yield and reduce manufacturing costs. In addition, it is added with COP Pre-opening wafer cassettes made from 1% to 5% of carbon nanotubes have the best predictability.

In addition, the present invention further tests the drop height of the front opening wafer cassette made of 5% by weight of carbon nanotubes, COC added carbon fiber and LCP. . It was found that the wafer cassette made of COP added with a weight percentage of 1% to 5% of carbon nanotubes can be dropped from a position of 90 cm without any damage; otherwise, the front open wafer made of LCP The box ruptures when it falls from a height of 50 cm. The above test results are in line with the general industry's recognition that the front-opening wafer cassette made by LCP has high hardness characteristics, but due to factors such as poor toughness and strength, it is actually in the event of impact. It is easy to be brittle, and the open-type wafer cassette made of the cyclic olefin composition as the main material has better elasticity and impact resistance.

Please also refer to Figure 3 and Table 1, which are the relative humidity test chart and the 0% relative humidity maintenance schedule. The COP is added with 1% to 5% by weight of carbon nanotubes, COC added carbon fiber and LCP. The prepared front open wafer cassette can compare the relative humidity of the inside of the box to 0%. Since the semiconductor box of the wafer cassette, the photomask box and the like need to have good airtightness to avoid contamination of the outside air or particles, the water inside the box can be quickly eliminated after a short time, and if the box body can be removed for a long time, Maintaining the low relative humidity means that the casing is not easily penetrated by water and air, and the airtight effect is good. Therefore, the relative humidity of the casing is further tested for the foregoing three.

As can be seen from Fig. 3 and Table 1, the COP adds a 1% to 5% by weight carbon nanotube front opening wafer cassette, which maintains the relative humidity in the box at 0% for up to 80 minutes. The time of the other two is comparable, which is much shorter than the COP adding 1% to 5% by weight of carbon nanotubes.

Please refer to Table 2, which is a test result test result list of the cyclic olefin composition of the present invention, which is used to display an open wafer cassette before the COP addition weight percentage is 2.8%~3.2% carbon nanotubes, and is applied to The results of the test of the important application characteristics of the semiconductor substrate transfer box.

The above table describes the test results of various characteristics, which can further define the application range of the cyclic olefin composition and the cycloolefin semiconductor substrate transfer cassette of the present invention. Furthermore, the characteristics of the cycloolefin semiconductor substrate transfer cassette are not only to pursue extreme values, but to select the most suitable material for different process requirements.

Among the foregoing application characteristics, a cycloolefin composition in which a carbon nanotube is added The specific gravity can be maintained between 1 and 1.2, and the general weight of LCP is about 1.5. In other words, for a semiconductor substrate transfer cassette of the same size, the weight of the cycloolefin composition as the main material can be reduced by 25% to 50%, that is, for example, for a 12-inch wafer cassette weighing 5 kg. Each cycloolefin wafer cassette will reduce the weight of 1.25 kg to 2.5 kg, which has substantial and obvious help for handling operations.

Further, the cyclic olefin composition has a water content of less than 0.01%, and is a material having a low water content, that is, moisture absorption phenomenon does not occur by itself, and therefore, the cycloolefin semiconductor substrate transfer container of the present invention is a wet semiconductor cleaning process. Also applicable.

Furthermore, the elongation at break of the cyclic olefin composition is about 5%, which is significantly larger than that of the LCP as the main material (the elongation at break of the LCP wafer cassette is usually less than 1%), indicating that the material extends more when the COP is impact resistant. Not immediately brittle.

It can also be seen from the above Table 2 that the cyclic olefin composition of the present invention has an impact strength of more than 30 (joules/meter) and falls between 30 (joules/meter) to 50 (joules/meter). The impact strength of COP or COC, which is generally not filled with carbon nanotubes, falls between 15 (Joules/meter) and 25 (Joules/meter), indicating that the addition of carbon nanotubes contributes to improved impact resistance.

Furthermore, the shrinkage ratio of the cyclic olefin composition is between about 0.1% and 0.5%, compared to the shrinkage rate of COP or COC of generally not added carbon nanotubes of about 0.3% to 0.8%. The shrinkage rate of the inventive cyclic olefin composition is low, indicating that the addition of carbon nanotubes contributes to the improvement of dimensional stability and thus the yield of the product.

In addition, the amount of the carbon nanotubes added may be different, and the cyclic olefin composition of the present invention may have different characteristics. When a carbon nanotube having a weight percentage of 2% to 2.8% is added, the cycloolefin semiconductor substrate transfer box may be used. The surface resistance falls between 10 ⁹ ~ 10 ¹² (unit: ohm / unit area; Ω / sq.) to provide antistatic properties of the transfer box; if the weight percentage is 2.8% ~ 3.2% In the case of a carbon nanotube, the surface resistance of the cycloolefin semiconductor substrate transfer cassette may fall between 10 ⁵ and 10 ⁹ (unit: ohm/unit area; Ω/sq.) to provide antistatic dissipation characteristics of the transfer case; If a carbon nanotube having a weight percentage of 3.2% to 5% is added, the surface resistance of the cycloolefin semiconductor substrate transfer cassette can be less than 10 ⁵ (unit: ohm/unit area; Ω/sq.) so that the transfer box has a conductor The characteristics, so the user can determine the amount of carbon nanotubes added according to actual needs, so that they have the desired characteristics of the transfer box.

The cyclic olefin composition of the present invention and the cycloolefin semiconductor substrate transfer case using the same do not limit the applicable appearance or size of the casing, and mainly lie in the technical features disclosed in the present invention, and the cyclic olefin compound is used as a main material. By further adding a specific proportion of carbon nanotubes, it is possible to manufacture a material composition excellent in performance and a semiconductor substrate transfer box made of the material composition, which can meet the strict cleanliness and high-efficiency protection requirements of the semiconductor process. .

Claims (12)

A cyclic olefin semiconductor substrate transfer box made of a cyclic olefin composition comprising a cycloolefin copolymer (COC) to which a carbon nanotube is added or a cycloolefin to which a carbon nanotube is added Cycloolefin polymer (COP), wherein the carbon nanotubes account for 1% to 5% by weight. The cycloolefin semiconductor substrate transfer cassette according to claim 1, wherein the carbon nanotubes account for 2% to 2.8% by weight. The cycloolefin semiconductor substrate transfer cassette according to claim 1, wherein the carbon nanotubes account for 2.8% to 3.2% by weight. The cycloolefin semiconductor substrate transfer cassette according to claim 1, wherein the carbon nanotubes account for 3.2% to 5% by weight. The cycloolefin semiconductor substrate transfer cassette according to any one of claims 1 to 4, which has a specific gravity of from 1 to 1.2. The cycloolefin semiconductor substrate transfer cassette according to any one of claims 1 to 4, which has a water content of less than 0.01%. The cycloolefin semiconductor substrate transfer cassette according to any one of claims 1 to 4, which has a shrinkage ratio of 0.1% to 0.5%. The cycloolefin semiconductor substrate transfer cassette according to any one of claims 1 to 4, which has an impact resistance of 30 (joules/meter) to 50 (joules/meter). A cyclic olefin composition comprising a cycloolefin copolymer (COC) to which a carbon nanotube is added or a cycloolefin polymer (COP) to which a carbon nanotube is added, wherein the carbon nanotubes occupy The weight percentage is 1% to 5%. The cyclic olefin composition of claim 9, wherein the carbon nanotubes comprise from 2% to 2.8% by weight. The cyclic olefin composition of claim 9, wherein the carbon nanotubes comprise from 2.8% to 3.2% by weight. The cyclic olefin composition of claim 9, wherein the carbon nanotubes comprise from 3.2% to 5% by weight.