JPH10250709A - Integrating facility for molding and filling container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent particle contamination of chemical substance used in manufacturing an integrated circuit by receiving facility for molding a container, a filling region for filling chemical substance and transfer of the container to the filling region all in contamination-free environments to manage and integrate processes for manufacturing and handling the container. SOLUTION: In order to manufacture a clean container and keep a clean state throughout a packaging process, 1-gallon bottle manufacturing facility of a clean room is provided adjacent to a manufacturing clean room. Strict attention is paid to a resin material of a container to be used for packaging chemical substance and air to be used in a blow-molding process. Appropriate resin is high density polyethylene with a low level in leaching of residual metal catalyst and organic leaching substance. Air to be used for blow-molding to form the container is highly filtered to prevent a bottle from being contaminated. Static electricity attracting particles in an atmosphere is removed by installing a static eliminator on bottle manufacturing facility and providing gas ionizer on a tunnel for carrying from the manufacturing clean room to a filling clean room.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION This invention relates to bottling of ultra-high purity chemicals for use in the manufacture of integrated circuits.

[0002]

2. Description of the Related Art The need for high purity chemicals continues to evolve to meet specifications with the increasing complexity of integrated circuit processes. Close attention must be paid to all sources that affect the purity of the process chemical from the production of the chemical to the point of use. US Patent 5,242,
One solution is described in US Pat. No. 468, where ultra-high purity cleaning and corrosive agents are prepared from gaseous raw materials at the point of use. Such high purity has an ultrapure water resistivity of at least 18 megohm-cm at 25 ° C., less than about 25 ppb of electrolytes other than the agent, fine particle content of less than 150 / ml and less than 0.2 micron in particle size, less than 10 / ml And the semiconductor production standard defined as total organic carbon of 100 ppb or less. Chemical containers are ions,
It is the largest potential source of organic and particulate contamination.

[0003]

Most container manufacturing facilities are not installed in a clean room environment. Transporting containers from a manufacturing facility to a chemical packaging facility further introduces contamination.
Due to non-clean manufacturing and shipping contamination, drums and bottles for high purity chemicals must be cleaned before filling them with high purity chemicals.

[0004]

SUMMARY OF THE INVENTION Integrated container manufacturing and chemical packaging facilities alleviate many of these contamination problems. Important issues in the manufacture and packaging of containers include component materials, resin selection, environmental pollution, and control of the blowing process. In the present invention, the control and integration of the manufacturing and packaging processes prevents particle contamination and reduces all metal contamination to less than 1 ppb.

[0005] As the microelectronics industry follows a path of constant development, suppliers of raw materials and equipment to this sector must likewise meet the needs of this changing market. Increasing device complexity has led to feature shrinkage, which has in turn raised interest in impurities contacting the wafer surface. In order to achieve the required purity of process chemicals at the surface of the wafer, a collaborative approach is essential to address all possible sources of chemical contamination. These sources include raw materials, chemical synthesis processes, purification processes, packaging processes, chemical containers, and delivery processes to wafer manufacturing facilities. As the purity specifications of process chemicals become increasingly stringent, the nature of the packaging must be improved to maintain the purity at which the chemicals are transported and stored prior to use.

[0006] In order to understand and eliminate the contribution of contaminants (metals and particulate matter) to the wafer process, it is important to characterize the entire container manufacturing and handling process. The parameters that affect the cleanliness of the chemical container are: o Type of constituent material or resin (chemical compatibility) o Cleanliness of resin manufacturing process o Cleanliness of blow molding manufacturing process o Environmental cleanliness after container manufacturing o Container handling process before cleaning and filling o Container cleaning process o The cleanliness of the environment used for cleaning and filling containers.

[0007] The manufacturing specifications for containers used for packaging electronic grade chemicals far exceed those found in ordinary industrial or consumer markets. Strict attention must be paid to the plastic resin raw materials used in the process as well as the air used in the blow molding process. If the bottle is awaited after a molding process that could contaminate the bolt, even though its resin and air are perfect, it renders the use of high purity chemicals unsuitable for packaging. Construction of a one gallon (3.78 L) bottle manufacturing facility in the clean room adjacent to the clean room to produce clean containers and maintain cleanness throughout the packaging process Possible contamination of chemicals It has been found to eliminate. This is the “integrated equipment” of the present invention.

[0008] Proper selection of the resin is important. High density polyethylene (HDPE) is the best choice for packaging electronic chemicals due to its excellent chemical resistance, strength, impact resistance, and ease of manufacture of various size containers (Hac
kett, T .; B. and K. Dillenbec
k, “Characterization Polye
Tile as a Packing Ma
terminal for High Purity Pr
process Chemicals ", Processedin
gs-Institute of Environment
ntal Sciences, 39th Annual
Technical Meeting, Las Ve
gas, NV May 2-7, 1993).

[0009] As the metal catalyst is used in the HDPE resin and remains in the resin, the residual catalyst can leach out of the polyethylene and enter the process chemistry. The catalytic metal is typically chromium or titanium. Prior to using HDPE resin in semiconductor packaging, metal leachability must be tested. In addition to the residual metal catalyst, many metals leach from HDPE, which has been shown to originate from the container manufacturing process rather than from the resin ("Determination of Leacha").
ble Metallic Impurities f
rom Semiconductor Chemica
l Packaging Material ", Pr
oceeding-Microcontaminati
on 94Conference, Santa Cla
ra, CA, Oct, 4-6, 1994, Talase
k, T. Hall, L .; Mallini, L, and
See Sewall, V .; reference).

[0010] Another important factor in the selection of HDPE is the content of organic leachables. Additives are typically easy to mix into HDPE resins because polyethylene is susceptible to oxidation by exposure to heat and ultraviolet light.
Commonly used processing stabilizers are phenol and phosphite compounds which scavenge free radicals. Light stabilizers are usually hindered amines, which control the UV damage of polyethylene. The content of organic substances in HDPE resin is determined by Soxhlet extraction method, supercritical fluid extraction method (“De
termination of Leachable
Organics from Semiconductor
r Chemical Packaging Mate
real by Supercritical Flu
id Extraction ”, Proceeding
s-Microcontamination 94 C
onference, Santa, Clara, CA,
Oct. 4-6, 1994-Talasek, T .; , H
all, L .; , And Knowles, D .; ) Or headspace chromatography. There is considerable variation in the content and composition of organic leachables between the various sources of HDPE resin manufacturers.
Organic materials leaching from polyethylene bottles are found in process chemicals and can be quantified (“Det
emission of Trace Organ
ic Impurities in Semiconductor
actor Processing Chemical
s ", Proceedings-Microconta
mination 91 Conference an
d Exposure, San Jose, CA,
Oct. 16-18, 1991-Camenzind,
M. , Tan, S .; , And Balazs, M, an
d “Identifying OrganicImp
urities in Inorganic Proc
ess Chemicals by Solid-Ph
as Extractions ”, Microcon
termination, 11 (6), 43-45, 19
93-Talasek, T .; , Vanatta, L .; ,
Lucero, B .; , And Schoenke,
T. ). The effects of these organics on the chemicals range from discoloration of the liquid to increasing the potential for particle release of the container over time. In the worst case, these organic materials leave residues on the wafer surface. The seriousness of the problem is directly related to the amount of organic leachables present in the resin, so an important resin selection criterion is to obtain low levels of organic leachables.

In a typical blow molding operation, conveyors, polishers, material handling equipment and blow molding machines introduce countless particles into the manufacturing environment. The working environment is open to outside environments with high air particle content and loading dock facilities. 1 million particles / ft
It is common for more than ³ (0.028 / m ³ ) air particles to be present in the air. Container manufacturers are generally unaware of pollution control issues and are not aware of the importance of particle regulation in their manufacturing area. However, in semiconductor chemical packaging, the nature of the air at the bottle manufacturing site is very important.

In the blow molding process, the molten polyethylene is extruded into a circular parison. The container mold is fixed around the parison and compressed air is injected to expand the molten parison to form the container. In this process,
If the compressed air contains particles, these particles will strike the inner surface of the container. As the container cools and solidifies, the particles physically adhere. These particles are difficult to remove by simple washing of the container. Therefore, the air used for blow molding must be highly filtered to prevent bottle contamination.

[0013] The static charge on the bottle is detrimental in various ways. The electrostatic charge attracts atmospheric particles, which reach the container, resulting in a high particle count in the process chemical. The particles themselves are likely to adhere to the outside of the container. In this case, the particles on the bottle are carried into the wafer manufacturing area. An air ionizer neutralizes the electrostatic charge resulting in the bursting of contaminating particles. The electrostatic charge of a particle is
It is also a safety issue due to the possibility of igniting flammable vapors in bottle filling operations. Two different antistatic devices are installed in the bottle manufacturing facility to remove static charge from the bottle. Both devices utilize a discharge, which is the most commonly used method for preventing static electricity (“Stat
ic Forces and Magnetic Fi
elds-Part 1: Research on A
Dhesion of Particles to C
harged Wafers Critical in
Control Control "-Mi
crocontinuation, October
1989-Ohmi, T .; , Inaba, H .; , And
Takenami, T .; ). Since these devices do not have a radiation source, the possibility of α-particle contamination is not introduced.
Immediately after the annealing step, the bottle is placed in the ion device
STAT6664 type ISOSTAT FLOWBAR)
Carried under. The air ionizer is designed to operate in a dynamic air flow device. This IS
The OSSTAT FLOWBAR is placed underneath a high efficiency particulate air filter to apply ionized clean air to a newly manufactured bottle.

Further, in order to reliably remove the electrostatic charge from the bottle, a built-in ionization chamber (trade name, ZSTAT62)
10) is placed in a tunnel that carries a 1 gallon (3.78 L) HDPE bottle from the bottle manufacturing cleanroom to the bottle filling cleanroom. The gas ionizer is connected to a source of compressed air to be filtered that has passed through a tungsten alloy emitter pin. The surface in contact with the flowing gas is made of Teflon which is injected for special use in a clean room. This ionized air sweeps around the container and neutralizes the charge on their surface.

This facility is designed with the feature of isolating particle sources that can contaminate one gallon blow molded bottles. The main feature is the separation of the extruder body and the blow molding machine head. The blow molding machine is a 15 ton Uniloy reciprocating screw, a 10 hp rotary drive with intermittent extrusion. The hydraulic air valves and heating elements used to operate the apparatus are isolated from the bottle forming process. There is a potential for oil leaks from the high pressure hydraulics of the molding machine, and thus a potential source of organic contamination in the blow molding process. A chamber is created around the molding machine to eliminate all of these particle sources.

Another primary source of particles is in the transfer of polyethylene resin pellets to a blow molding machine. When additional resin is needed,
The top air blower of the blow molding machine operates. By isolating parts of the device, the working area is not contaminated. Other steps isolated from the blow molding process are mills, remill bins, mixers, and vacuum equipment to remove resin from silos. All this equipment, including the molding machine, is housed in a room isolated from the molding floor, and maintains a lower pressure than the clean room molding area to ensure clean production of blow molded bottles.

[0017] Today's blow molding processes have advanced significantly over the last decade. These advances result in excellent bottles in terms of uniformity and consistency. One such development is in the control of resin placement in the molten parison. After melting the polyethylene resin in the extruder, the melt is extruded through an annular die to form a parison. Because the bolts include curves, pinch-off points, handles, and changing dimensions, the ideal parison shape needs to be changed to compensate for changing bottle dimensions. The blow molding machine used in this facility can adjust the hundreds of dimensions over the length of the parison and place a re-suitable amount of resin in the bottle.

Another area of improvement is the area of mold design. The effect of adequate mold cooling and control is important in maintaining bottle dimensions. The effect of failure to control the dimensions of the neck and screw leads to breakage and leaking containers in drop tests. Recent advances in the automation of the Uniloy MACO8000 type controller allow for a consistent round of clock production in the blow molding process.

The nature of the air used to make the bottles is an important variable in overall bottle cleanliness. Three specific areas that require a high degree of filtered air are the blown air used to expand the molten polymer parison, the leak detector air blown directly into the bottle, and the air in the entire manufacturing environment. The main thing is the nature of the blowing air. If the air contains particles, the particles will collide with and adhere to the inner surface of the container. These attached particles are difficult to remove by washing the vessel and remain attached until solvated by active process chemicals. Therefore, it is essential that the blown air be highly filtered and low in particulate contamination. The effect of the nature of the blowing air on the process chemistry has been measured previously ("Understanding the Part."
ice Shedding Phenomenai
n Polyethylene Container
for Semiconductor Process
Chemicals ", Proceedings-M
microcontainment 91 Conf
erence and Exposure, San
Jose, CA, Oct. 16-18, 1991-H
ackett, T .; B. , And Dillenbec
k, K. ). Without blown air filtration, the total number of particles in sulfuric acid is initially high, followed by the release of particles into the process chemical. On the other hand, when air was purified, the level of particles in the sulfuric acid remained constant for the duration of the test.

The air used for the leak detector must also be highly filtered. The leak detector is a quality assurance that guarantees the integrity of each bottle. Each bottle is pressurized with air and takes multiple pressure readings. For holes with a diameter of 1 mm or more in the bottle, the final pressure reading is part of the initial pressure reading and the bottle fails. Smaller holes in the bottle are detected by comparing the change between the previous bottle and the pressure reading of the current bottle being tested. Since the leak detector air is injected directly into each bottle, the air must be low in particles. The nature of the air in the production facility is important for maintaining the cleanliness of the outside of the bottle.
The static charge of the plastic bottle attracts particles in the air. Particles attached to the outside of the bottle are likely to be carried into the wafer manufacturing area as a potential source of contamination. The nature of the air in the wafer fabrication area is routinely monitored at various locations in the clean room. The entire manufacturing area is class 100
Designed to include sufficient high efficiency particulate filtration to obtain a rating of zero. The arrangement of the high efficiency particulate air filter is extremely asymmetric to protect the opening of the bottle.

In a typical bottle making and filling scheme, molded bottles are manufactured at another location and sent to a filling location. Normal bottle production does not take place in a clean room, the bottles are transported to a filling site in cardboard overpacks.
During transport, some of the cardboard dust will inevitably adhere to the outside of the bottle, and some will cause particulate matter and metal contamination into the container ("Static").
Forces and Magnetic Field
ds-Part 1-Research onAdhe
session of Particles to Char
ged Wafers Critical in Co
natamination Control ”-Micr
oconmination, October 198
9-Ohmi, T .; , Inba, H .; , And Take
enami, T .; ). The cleanliness of the bottles sent in the cardboard overpack was tested before filling and compared to bottles manufactured in a clean room environment (see Table 1).

Particles on the outer surface of bottles manufactured in standard and clean room environments

[Table 1] The two sets of data are two non-parametric tests (Introduction to the Theo).
ry of Non-Paramic Stat
istics, John Wiley and Son
s, New York, 1978-Randles
R. , H .; , An Wolfe) was used to determine the difference between bottles manufactured in a clean room environment and a standard environment. These tests showed that bottles produced in a clean room environment had a statistically significantly lower surface particle count.

While the level of particles outside the bottle is a concern for reducing the level of contamination introduced into the wafer production cleanroom, particles in chemicals are of primary interest to customers.
In a drum dispense, particles can be reduced by circulating through a filter in a chemical distribution device before introducing the chemical into the distribution line. It is important to keep the particles in chemicals sent to customers low, as luxurious pre-cleaning before introduction into the process bath is not possible with bottled chemicals. Table 2 shows the improvements received after the realization of the integrated clean room blow molding facility.

Number of particles in sulfuric acid-clean room production bottle v
s. Standard bottle

[Table 2] Tests show that sulfuric acid filled with the integrated equipment of the present invention has a statistically significantly higher purity level than sulfuric acid filled in a conventional manner into bottles not molded in the integrated equipment.

In the blow molding process, the high density polyethylene resin is heated above its melting point and extruded through a thin annular die. During this process, the HDPE molecules elongate and introduce internal stress to the polymer. Annealing is the process of removing the internal stress of the polymer molecules and causing the plastic bottle to shrink. Polymer
Annealing of the container can be performed in two ways. The first method is to store the bottles in a warehouse for several days to give a natural anneal. The natural anneal is slow due to the limited mobility of the high molecular weight polyethylene chain. The second method is a forced cure. this is,
This is accomplished by placing the annealing units in line with the bottle handling device. The annealing unit consists of a heating tunnel that raises the temperature of the bottle and facilitates the movement of polyethylene molecules. By exciting the polymer, the plastic relaxation process quickly progressed and the plastic container was brought to its final dimensions in minutes.

The motion Gemini (Moti)
On Gemini) The idea in a 1000 unit can change the amount of infrared radiation as well as the speed of the bottle passing through the unit. Typically, a temperature of 593 ° C. is used for the annealing unit. Care must be taken to avoid melting of the plastic. The purpose of the annealing unit is to achieve the same level of polymer shrinkage that occurs naturally in warehousing of bottles before use. This method provides a consistent bottle with no dimensional change,
It can be sent continuously to an automated filling unit.

[0027]

The chemicals for the semiconductor industry can be significantly improved through the use of equipment that integrates container manufacturing and packaging. Key elements of this improvement include: • The polyethylene resin must be carefully managed with respect to metal catalysts, stabilizers, plasticizers, and release agents.

The nature of the air around the blow molding machine and the nature of the blown air must be non-contaminating for the container.

A clean room container manufacturing facility capable of directly delivering zero contamination-free bottles to a clean room packaging facility.

The result of such an effort is a clean chemistry that is sent to Microelectronics customers without extra contamination inside and outside the container.

Claims (8)

[Claims] 1. A facility for molding a container using a molten resin; a filling area adjacent to the facility for filling the container with ultrapure chemicals; and means for transporting the container to the filling area. An integrated system for producing ultra-high purity chemicals in containers, wherein said equipment, said area, and said means of transport are all housed in a clean environment that meets semiconductor manufacturing standards. 2. The integrated manufacturing system according to claim 1, wherein said resin comprises a high-density polyethylene resin, a halogenated carbon polymer resin, a polypropylene resin or nylon. 3. The integrated manufacturing system according to claim 1, wherein said container is blow molded. 4. The integrated manufacturing system according to claim 1, wherein said transportation means is installed in a tunnel. 5. The integrated manufacturing system according to claim 1, wherein the container is formed at a speed substantially equal to a speed at which the container is filled. 6. The ultra-high-purity chemical substance includes sulfuric acid, acetone, hydrogen peroxide, isopropyl alcohol, phosphoric acid,
2. The integrated production system according to claim 1, wherein the system is nitric acid, hydrochloric acid or aqueous hydrogen fluoride. 7. The integrated manufacturing system according to claim 1, wherein the container is a bottle, a drum, or a transport pack. 8. Forming a container; testing the container for leaks with highly filtered air; exposing the container to ionized air; transporting the container to a filling area; exposing the container to ionized air; And filling the
A method for manufacturing containers for ultrahigh-purity chemicals used in the manufacture of semiconductor wafers, wherein all the steps are performed in an environment maintained in a pollution-free state in accordance with semiconductor manufacturing standards.