JPH11191548A - Treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a treatment apparatus which prevents an atmosphere inside a clean draft from being contaminated with various generated gases, by a method wherein a substrate which is immersed in an immersion tank is housed so as to be exposed through a second opening which can be brought into close contact with a first opening, and an enclosure which is provided with a circulation pipe into which a gas is made to flow is arranged and installed in a region in which the substrate is housed. SOLUTION: An air which is highly purified is introduced from a ventilation pipe 19, and it is always sucked from a ventilation pipe 20. When an enclosure 13 and an enclosure 15 are united, a cleaning solution (an aqueous cleaning solution composed of ammonium hydroxide and of hydrogen peroxide) is introduced into an immersion tank 11. After a silicon wafer 9 is cleaned, the cleaning solution is discharged from the same conveyance system. As a result, an atmosphere in an environment in which a treatment apparatus is arranged and installed is not contaminated with ammonia when the silicon wafer 9 is cleaned. In this execution state, a shielding plate 36 and a shielding plate 37 which can be opened and shut are installed at an opening 16 of the enclosure 13 and at an opening 17 of the enclosure 15. As a result, the productivity and the economy of the silicon wafer 9 can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing apparatus for performing processes such as cleaning and etching on substrates and the like when manufacturing semiconductor substrates such as silicon wafers and various devices.

[0002]

2. Description of the Related Art In the process of manufacturing semiconductors and the like, chemical treatment for cleaning the surface of a substrate such as a silicon wafer is frequently performed. In order to remove metals, organic substances, fine particles, and other substances from the surface of the substrate, it is necessary to wash the substrate vigorously, and therefore, usually, a plurality of steps consisting of chemical solution treatment and rinsing with ultrapure water are combined. A wash sequence has been applied. In particular, RCA cleaning is most widely used as a cleaning sequence for cleaning silicon wafers. RCA cleaning includes SC-1 (aqueous cleaning solution containing ammonium hydroxide and hydrogen peroxide), diluted hydrofluoric acid (H
_{F: H 2 O = 1:} 50~200; called DHF), SC-
2 (aqueous cleaning liquid containing hydrochloric acid and hydrogen peroxide) and a rinsing with ultrapure water. In a standard cleaning sequence, SC-1 → pure water rinsing → dilute hydrofluoric acid → Rinse with pure water → SC-2 → Rinse with pure water → drying (spin drying or isopropyl alcohol vapor drying).

[0003] Cleaning devices for performing a cleaning sequence are roughly classified into a single station system and a multi-tank immersion system. In any case, a silicon wafer is stored in a carrier made of a fluororesin or the like. Alternatively, a cleaning sequence is performed on a plurality of silicon wafers while using this type of carrier only for transferring the silicon wafers. The single-station type processing apparatus is an apparatus that executes all cleaning sequences in one cleaning tank,
On the other hand, a multi-tank immersion processing apparatus arranges a chemical solution tank and a pure water tank as many as necessary for a cleaning sequence, sequentially transports a carrier containing silicon wafers by a robot arm or the like, and places the silicon wafers in each tank. This is a device that executes a cleaning sequence by immersing it in a chemical solution and pure water. By the way, removing a substance such as a metal, an organic substance, or a fine particle from the surface of a silicon wafer usually requires a chemical solution treatment for 10 minutes or more. Since the process is performed in one washing tank, there is an advantage that a floor area is small, but productivity is low. Therefore, a general production plant usually uses a multi-tank immersion type processing apparatus.

[0004] In the above multi-tank immersion processing apparatus, a carrier containing a substrate such as a silicon wafer processed in the cleaning tank is pulled up from the cleaning tank by a robot arm, and the carrier is transported to a rinse tank. The operation of immersing the substrate in pure water in the rinsing tank is repeated. Generally, the surface of the substrate immediately after the chemical treatment tends to adhere fine particles in the air, so the cleaning tank and robot arm are placed in a clean draft equipped with a filter for ultrafine particles with chemical resistance. SC-1 and SC-2 are 60 to 8
SC-1 and SC
Hydrogen peroxide contained in -2 decomposes and the chemical liquid foams strongly, and hydrochloric acid, ammonia and the like are scattered from the surface of the chemical liquid into the clean draft. Therefore, for the clean draft, in order to discharge the gaseous substance from the inside of the clean draft, a strong exhaust is performed from a part of the rear surface or a part of the lower part.

[0005] In chemical treatment such as etching, a sequence similar to the above-mentioned cleaning is applied. For example, treatment with a mixed solution of sulfuric acid and hydrogen peroxide for removing photoresist from a substrate is performed by: 13
Heating to 0 to 150 ° C. generates mist of sulfuric acid. Further, in the phosphoric acid treatment for removing the nitride film from the substrate, a phosphoric acid mist is generated because the phosphoric acid solution is heated to 160 to 170 ° C. In addition, in the etching of a silicon wafer with a mixed acid of nitric acid and hydrofluoric acid, these reactions cause the (toxic) of nitrogen dioxide and hydrofluoric acid.
Gas is generated. Therefore, even in the case of chemical treatment such as etching, in order to exhaust gaseous substances from the inside of the clean draft, it is necessary to perform strong exhaustion from a part of the back surface or a part of the lower surface.

[0006]

If a slight amount of hydrochloric acid gas, sulfuric acid mist, or the like is contained in an atmosphere in a clean room for semiconductors, contamination of the substrate exposed in the atmosphere with fine particles may occur. If the atmosphere contains hydrofluoric acid gas or the like, boron is released from the dust-proof filter to cause p-type contamination on the substrate, and phosphoric acid mist causes n-type contamination. . Then, super LSI
It is desired that the acid concentration in the atmosphere in the clean room for producing the phenol is controlled to be 0.1 ppb or less. Also, with the ultra-high integration of VLSI, unit devices are becoming ultra-miniaturized, so chemically amplified photoresists have been used in photolithography, but if ammonia is present in the atmosphere in the clean room, LS is adversely affected during development.
It is also desired that the concentration of ammonia in the atmosphere in the lithography clean room for manufacturing I be controlled to be 0.1 ppb or less.

However, in the case of a normal clean room, organic matter, sulfuric acid,
The concentration of hydrochloric acid or ammonia is usually 1 ppb or more.
In some cases, the immersion treatment apparatus is one of the sources of contamination of the chemical substance. As described above, when the chemical substance is present in the atmosphere, the chemical substance is adsorbed on the surface of the substrate exposed to the atmosphere, and as in a certain organic substance,
In the process of forming an oxide film or a polysilicon film, not only the characteristics of the device are directly deteriorated, but also fine particles of ammonium sulfate or the like cause fine particle contamination.

When strong exhaust is locally performed in a clean draft in which a processing apparatus for performing the above chemical treatment is introduced, the flow rate of air supplied from the ultrafine particle filter is adjusted to about 0.5 m / sec. Therefore, the laminar flow at the corner becomes turbulent. As described above, in the processing apparatus of the multi-tank immersion method, the number of operations in which the carrier containing the substrate is pulled up from the cleaning tank containing the chemical solution by the robot arm and transported to the rinsing tank is inevitably increased. Since the chemical solution has adhered to the pulled-up substrate, before the carrier enters the rinsing tank, acidic gas, acid mist, or ammonia, etc., from the chemical solution attached to the substrate is scattered into the draft by turbulent air. I do. Also, since the pure water in the rinsing tank always overflows, the atmosphere contaminated with acids, ammonia, etc., which is discarded from other drain pipes, through a drain pipe for discharging the pure water. Backflow into clean draft. Therefore, the concentration of hydrochloric acid ions, sulfate ions, ammonia, or the like in the atmosphere in the clean draft partially reaches several hundred ppb. Such a contaminated atmosphere can be caused by opening and closing the draft door (for example,
There is a problem that the device flows into the clean room when the wafer carrier is loaded or unloaded, etc., and the characteristics of the device manufactured as described above are deteriorated or defective.

Further, the acids contaminating the atmosphere in the clean draft generate fine rust on the surface of various metals constituting a transfer mechanism typified by a robot arm disposed in the clean draft, and the surface is cleaned. This causes contamination of iron, aluminum and the like on the highly active surface of the substrate. Generally, the concentration of metal on the substrate surface expected in the VLSI process is about 10 ⁸ atoms / cm ² , but within one year after the start of use of the processing apparatus, the concentration of iron, aluminum, etc. Concentration is 10 ¹⁰ atoms / cm
² or more. Therefore, there is a problem that sufficient cleanliness cannot be obtained even after the substrate is washed.

The present invention has been made in order to solve the above problems, and relates to an immersion treatment performed in a clean draft, and prevents contamination of an atmosphere in the clean draft by various gases or mist generated from a chemical solution tank or the like. In addition to contributing to maintaining the cleanliness of the entire clean room, it is also possible to significantly reduce contamination of the substrate and the like by executing a processing sequence while isolating the clean substrate after rinsing from the gas and mist. An object of the present invention is to provide a processing apparatus capable of improving the production yield of devices.

[0011]

A processing apparatus according to the present invention accommodates an immersion tank so as to be exposed through a first opening, and circulates a first gas to a region where the immersion tank is accommodated. A first housing provided with a first flow pipe for causing the first housing to be immersed, and a substrate immersed in the immersion tank are housed so as to be exposed through a second opening that can be in close contact with the first opening, And a second housing provided with a second flow pipe for flowing a second gas through a region where the substrate is stored.

According to the processing apparatus of the present invention, the immersion tank is housed so as to be exposed through the first opening, and the first gas for flowing the first gas through the area where the immersion tank is housed. A first housing provided with a flow pipe, and a substrate immersed in the immersion tank are housed so as to be exposed through a second opening that can be in close contact with the first opening, and the substrate is housed therein. And a second housing provided with a second flow pipe for flowing the second gas through the first and second openings through the first and second openings. And while the first and second gases are flowing through the first and second flow pipes, the substrate can be immersed or pulled into the immersion tank. Gas and mist, etc., to prevent atmospheric pollution. Significantly reduce the contamination of the substrate or the like by performing a sequence of dipping treatment while isolating the substrate or the like from such, it is possible to realize an improvement of the production efficiency of the various devices.

That is, the first opening and the second opening are brought into close contact with each other to combine the first and second housings, and a high-purity dust-free gas is supplied as a second gas from the second flow pipe. When the substrate is immersed in the immersion tank by sucking the first gas including the second gas from the first circulation pipe while introducing the gas, various gases and mist generated from the immersion tank are sucked from the first circulation pipe. Is done. Next, after a lapse of a predetermined time, the substrate is taken out of the immersion tank, the first gas is continuously sucked from the first circulation pipe, and then the introduction of the second gas through the second circulation pipe is stopped. When the first and second housings are released from each other, the atmosphere around the processing apparatus is not contaminated by various gases and mist generated from the immersion tank, and the substrate is exposed to the atmosphere around the processing apparatus. The sequence of the immersion process can be executed without any need. Further, the processing apparatus according to the present invention houses the first immersion tank so as to be exposed through the first opening, and circulates the first gas to the area where the first immersion tank is housed. A first housing provided with a first distribution pipe for
A second immersion tank was housed so as to be exposed through the second opening, and a second circulation pipe for circulating a second gas through an area where the second immersion tank was housed was provided. Second
And a substrate immersed in the first and second immersion tanks are stored so as to be exposed through a third opening that can be in close contact with the first and second openings, and the substrate is A third gas for flowing the third gas through the accommodated area
And a third housing provided with the above-mentioned flow pipe.

According to the processing apparatus of the present invention, the first immersion tank is housed so as to be exposed through the first opening, and the first gas is supplied to the area where the first immersion tank is housed. A first housing provided with a first circulation pipe for circulation and a second immersion tank are housed so as to be exposed through the second opening, and in a region where the second immersion tank is housed. On the other hand, a second housing provided with a second flow pipe for flowing the second gas, and a substrate immersed in the first and second immersion tanks,
And a third flow pipe which is housed so as to be exposed through a third opening which can be in close contact with the second opening, and which has a third flow pipe for flowing a third gas to a region where the substrate is housed. The first and third housings or the second and third housings through the first and third openings or the second and third openings. While flowing the first and third gases or the second and third gases through the first and third flow pipes or the second and third flow pipes, the substrate into the first or second immersion tank; Immersion, lifting, etc., can prevent contamination of the atmosphere by various gases and mist generated from the first and second immersion tanks, and isolate the substrate and the like from the gases and mist. Sequence of immersion process while Significantly reduce the contamination of the substrate such as by row, it is possible to realize an improvement of the production efficiency of the various devices.

The present invention provides a processing apparatus for continuously executing a multi-stage sequence. That is, a plurality of immersion treatments, usually, a chemical treatment and a rinsing treatment are continuously performed. For example, the chemical treatment is performed in a first immersion tank, and the rinsing treatment is performed in a second immersion tank. carry out.

That is, the first opening and the third opening are brought into close contact with each other to combine the first and third housings, and a high-purity dust-free gas is supplied as the third gas from the third flow pipe. When the substrate is immersed in the first immersion tank by sucking the first gas including the third gas from the first circulation pipe while introducing the gas, the various gases and mist generated from the first immersion tank become It is sucked from the circulation pipe of No. 1. Next, after a predetermined time has elapsed, the substrate is moved to the first position.
After taking out the first gas from the immersion tank and continuously sucking the first gas from the first circulation pipe, the introduction of the third gas through the third circulation pipe is stopped to combine the first and third housings. When released, a sequence of immersion processing is executed without contaminating the atmosphere around the processing apparatus with various gases and mist generated from the first immersion tank and exposing the substrate to the atmosphere around the processing apparatus. be able to. Next, while ventilating the first and second flow pipes, the second opening and the third opening are brought into close contact with each other to unite the second and third housings, and the same operation as above is performed. If performed, the atmosphere around the processing apparatus is not contaminated by various gases and mist generated from the second immersion tank, and the sequence of the immersion processing is continuously performed without exposing the substrate to the atmosphere around the processing apparatus. Can be performed. Therefore, by arranging a larger number of housings containing the immersion tanks, the atmosphere around the processing apparatus is not contaminated by various gases or mist generated from the immersion tanks for any processing sequence, and Is not exposed to the atmosphere around the processing apparatus.

Further, the processing apparatus according to the present invention comprises an immersion tank, first and second housings which form a space in which the immersion tank is sealed and which can be separated from each other; And a first and a second circulation pipes arranged in the first and second housings so that the gas can be circulated.

According to the processing apparatus of the present invention, the immersion tank, the first and second housings which form a space in which the immersion tank is sealed and which can be separated from each other, and at least gas is supplied to the space. And the first and second circulation pipes disposed in the first and second housings so that the
Since the first and second gases can be passed through the first and second flow pipes to the space while the processing object represented by the substrate or the like is being immersed in the immersion tank or pulled up, it can be carried out. In addition to preventing contamination of the atmosphere by various gases and mist generated from the immersion tank, etc., the immersion processing sequence is performed while isolating the substrate and the like from the gas and mist, thereby significantly reducing the contamination of the substrate and the like. In addition, it is possible to improve the production efficiency of various devices.

In the present invention, the material constituting the housing is
There is no particular limitation as long as the form does not cause corrosion or the like due to a liquid or the like used in the atmosphere or the inside of the housing, and the form is maintained. For example, various resin materials, particularly fluorine resins, etc. are preferably used. be able to. Further, quartz glass may be used for all or part of the housing. The term that the openings of the housing are in close contact is a concept that includes not only a state in which the respective openings are in contact with each other and in close contact with each other, but also a state in which both the openings are in non-contact with each other while maintaining a predetermined clearance. For example, the case where a seal part such as an O-ring is interposed is also included.

Conventionally, in a multi-tank immersion treatment, a plurality of immersion tanks are arranged and a substrate to be processed is moved and immersed sequentially. In the present invention, the above conventional immersion method can be applied,
The present invention also provides the following mechanism. That is, from the housing in which the immersion tank is stored, the immersion tank moves so as to immerse the substrate and the like through the opening of the housing that stores the substrate and the like and moves so as to be in close contact with the opening of the housing. Thus, after the substrate is immersed in the solution in the immersion tank and held for a predetermined time, the immersion tank has a mechanism for detaching the substrate or the like from the solution and returning to the original position.

Further, as the substrate immersed in the immersion tank,
In particular, a substrate such as a silicon wafer for VLSI or gallium arsenide can be mentioned. However, the present invention can be applied not only to a substrate for a general semiconductor device but also to a glass substrate or the like applied to a liquid crystal display device or the like, and these can be appropriately selected as needed. .

Here, the housing housing the immersion tank will be described. A flow pipe for flowing the gas provided in the housing,
It is provided mainly for discharging toxic gas generated from the immersion tank in the housing to the outside, and is desirably disposed farther from an opening provided in the housing. Usually, the flow pipe is provided on a side surface slightly away from the bottom surface of the housing. This is a countermeasure in the case where the solution overflows from the immersion tank, and it is desirable to provide a pipe port for discharging the solution overflowing from the immersion tank on the bottom surface of the housing. In addition, the method of exhaust is not particularly limited, and may be selected according to the content of the chemical treatment. Usually, the exhaust method is connected to the exhaust duct through an exhaust pipe via a small acid-resistant exhaust fan or the like capable of adjusting the exhaust speed. I just need.

The shape of the immersion tank may be such that a substrate or the like is accommodated therein. However, when the substrate or the like is held in a carrier described later, the carrier is surely immersed and the amount of the solution is reduced. It is important not to increase more than necessary. Quartz glass is most preferable as the material of the immersion tank, but is not limited as long as it does not cause modification such as corrosion due to the solution held in the immersion tank and hardly generates dust. Is also possible. Furthermore, the solution held in the immersion tank is appropriately set depending on the intended treatment and the like. For example, SC-1, SC-2, a mixed solution of sulfuric acid and hydrogen peroxide, diluted hydrofluoric acid, and ammonium fluoride buffered hydrofluoric acid , A mixed solution of nitric hydrofluoric acid and ultrapure water. In this case, if necessary, a pipe for introducing a liquid or gas into the immersion tank from outside the housing or a pipe for discharging the liquid or the like from the inside of the immersion tank to the outside of the housing may be provided, and the material of the pipe is quartz glass. It is desirable to use such as. According to such a configuration, processing steps using a plurality of types of solutions can be easily and continuously realized in one immersion tank. In addition, in order to stably hold the immersion tank, it is desirable to provide a holder for holding the immersion tank in the housing. In general, the solution held in the immersion tank is often heated during use.Therefore, if necessary, a heating mechanism for heating the immersion tank is mounted on the holding table, or the holding table itself has a heat retaining function. do it. When a holding table is mounted, as a material of the holding table, a fluorine resin or the like may be used as long as the solution held in the immersion tank is not heated. It is desirable to use a ceramic such as silicon.

Further, the washing operation of immersing the substrate or the like in the immersion tank and taking it out of the immersion tank is achieved by, for example, moving the immersion tank up and down or moving the carrier containing the substrate and the like up and down. be able to. Here, the vertical movement of the immersion tank can be realized by, for example, fixing a holding table holding the immersion tank to a support column or the like, and raising and lowering the support column by hydraulic pressure or the like. On the other hand, the up and down movement of the carrier containing the substrate etc.
For example, it can be realized by raising and lowering two support columns that penetrate the bottom surface of the housing housing the immersion tank by hydraulic pressure or the like. In this case, for example, 90
A rotation mechanism is attached, and a hook is provided at the tip of the support column, and the carrier is transferred by rotating the hook and slightly moving the housing containing the substrate and the like held by the carrier in the horizontal direction. It is good to take a configuration.
As the material of the support column, it is desirable to use a material having high mechanical strength and low dust generation, such as a carbon silicon tube, an alumina tube, a metal tube coated with a fluororesin, or a PEEK material.

Next, a case in which a substrate and the like are stored will be described. A flow pipe for flowing the gas provided in the housing,
It is mainly provided for introducing a gas with a high degree of cleanliness and chemically into the housing,
It is desirable that the flow pipe is disposed more distally than the second opening. Here, air is usually used as the gas sent from the flow pipe, but an inert gas typified by nitrogen, argon, or the like can be used as needed. By passing through a precision filter for removing fine particles of 01 μm, in particular, a ceramic filter, it is possible to obtain a high-purity product having cleanliness necessary for a semiconductor manufacturing process. Also, for example, if a gas heating tube is mounted immediately before the flow tube, the substrate and the like can be heated prior to processing, so that the temperature of the solution is prevented from lowering when the substrate is immersed in the solution in the immersion tank. Thus, the time required for processing the substrate can be effectively reduced. At this time, the material of the gas heating tube is desirably quartz glass or the like, and a method of heating the snake tube is usually sufficiently applicable.

In storing the substrate in the housing, the substrate surface is exposed so that at least the surface of the substrate can come into contact with the solution in the immersion tank. The form in which the substrate is housed in the housing is not limited as long as the above conditions are satisfied, and is appropriately set in consideration of the shape, quantity, immersion method, and the like of the substrate. As described above, in the case of a method in which the immersion tank moves, for example, a holding unit that holds a substrate or the like may be provided in a housing to hold the substrate.
Usually, a plurality of substrates and the like are held in a carrier, and the carrier is housed in a housing. At this time, it is necessary to provide a hook or the like for holding the carrier in the housing. In addition, as described above, in the case of a method in which the carrier moves, for example, a recess may be provided to which the hook of the support column that moves the carrier is hooked. In order to prevent contamination of the substrate and the like due to elution of chemical substances and dust generation, it is desirable that the carrier and hooks in contact with the carrier are made of quartz glass, fluororesin, or the like. In addition, as long as the opening of the housing that houses the substrate is configured to be in close contact with the housing that houses the immersion tank, the form is not particularly limited. Note that in the case where the housing for housing the substrate is moved, any mechanism with reduced dust generation can be applied. In addition, in order to cope with the movement of the holding table that holds the immersion tank and the movement of the housing that stores the substrate, each flow pipe and the pipes connected to them are provided with:
It is desirable to provide a flexible tube part made of PFA or the like, which is a fluororesin, in a part thereof.

According to the present invention, a housing group accommodating the immersion tank is provided, and the housing accommodating the substrate is sequentially moved with respect to each of the housing groups, thereby processing the substrate or the like. Can be continuously performed. At this time,
The housing that houses the immersion tank and the substrate can have the same configuration as the above-described housing. At this time, the solution or the like in the immersion tank stored in each of the housing groups can be introduced into each immersion tank based on a function required for a required processing sequence. When the housing containing the substrate is moved relative to the housing group containing the immersion tank, any mechanism that reduces dust generation can be applied. For example, a commercially available robot can be used. can do. In this manner, the housing group housing the immersion tank is provided, and the housing housing the substrate is sequentially moved with respect to each of the housing groups. Can take action. However, when the concentration of the solution held in the immersion tank is high, and particularly when a large amount of gas that is harmful to a living body or an environment due to heating of the solution is generated, the housing housing the immersion tank and the substrate It is difficult to reliably discharge the generated gas through the flow pipe unless the housing that houses the gas is integrated. Therefore, for example, a switch that can close the opening is provided at the opening of the housing that houses the immersion tank, and the housing that houses the immersion tank and the housing that houses the substrate are combined. If the switch is closed while leaving a small gap in which the gas can be sufficiently exhausted by the flow pipe when not in a state where the gas flows, the generated gas can be reliably discharged through the flow pipe. Become. Here, as the switch, for example, a switch to which a sliding door system using a fluorine resin plate having a small friction coefficient or the like is applied is simple.

Further, a solution is attached to the substrate or the like taken out of the immersion tank or the carrier holding the same immediately after being taken out of the immersion tank. Takes some time, and a certain amount of the chemical solution remains attached to them. The solution may be a source of gas that is harmful to living organisms and the environment. In this case, it is desirable to provide a switch of a drawer type or the like capable of closing the opening at the opening of the housing containing the substrate. Here, the switch is desirably made of fluororesin or the like.For example, an exhaust pipe is provided on the upper surface of the switch, and when the opening is blocked by the switch, gas sent from the flow pipe is exhausted. To be controlled. The closing of the opening by the switch is performed at the same time when the housing housing the board is moved, and when the housing is moved, the board and the carrier are closed with respect to the environment in which the housing is provided. It is configured such that the solution or the like does not cause contamination such as gas and mist. Furthermore, when the housing housing the substrate is moved, the solution dropped from the substrate or the carrier may be collected in a drawer of the switch or the like, and at this time, the environment in which the housing is disposed Can be more reliably prevented from being contaminated by the solution. Note that, depending on the type of the solution held in the immersion tank, the adhesion to the substrate or carrier taken out of the immersion tank may be small. In this case, the switch may be of a sliding door type, and if the opening is closed by moving the housing, control may be performed so as to stop gas supply from the distribution pipe.

The main object of the present invention is to prevent the atmosphere around the processing apparatus from being contaminated by the solution necessary for the processing even if the substrate or the like is subjected to a multi-stage immersion processing in a predetermined sequence. That is. As mentioned above,
The processing by the processing apparatus of the present invention is performed in a closed space formed by combining a housing accommodating a substrate or the like and a housing accommodating an immersion tank. At this time, gas is fed into the closed space from a flow pipe provided in the housing in which the substrate is stored, and gas is exhausted from a flow pipe provided in the housing in which the immersion tank is stored. Since processing and movement of the substrate and the like are performed in the atmosphere,
Pollution in the atmosphere in which the housing is arranged does not occur in principle. In particular, the surface of the purified silicon or its oxide film strongly adsorbs organic substances in the atmosphere, so that there is a danger of easily causing contamination. Since the substrate is processed and moved in the atmosphere described above, contamination on the substrate and the like is significantly reduced.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a processing apparatus according to the present invention will be described with reference to the drawings. In each of the drawings, the same reference numerals are given to the common components unless otherwise required, and the description is omitted.

FIG. 1 is a diagram showing a configuration of a clean booth in which the processing apparatus of the present invention is installed.

As shown in FIG. 1, the clean booth is
Two anion exchange fiber filters 1a and 1b and two cation exchange fiber filters 2a and 2b are respectively arranged in series upstream of the ULPA filter 3 for removing fine particles, and the flow rate of the cleaning air by the fan 4 is set to 0.1. By setting the speed as low as 0.2 m / sec, the atmosphere in the clean booth is configured to keep chemically sufficient cleanliness when there is no load. Further, the processing device 5 is installed in a space formed by the side wall 6 and the grating 7, and the measurement and evaluation of the chemical substance leaked from the processing device 5 is performed by closing the transparent plastic door 8 in front of the processing device 5. The air before and after the treatment by
2 with the impinger with ultra pure water (not shown) set above
Sampling was performed for 0 minutes, and the collected sample was analyzed by ion chromatography. According to the clean booth shown in FIG. 1, Cl, F, NO ₃ , SO ₄ and NH ₄
0.1 ppb or less could be guaranteed for any of the _three concentrations. Furthermore, since the flow velocity of the air in the clean booth is small, the contamination caused by the processing device 5 can be sufficiently evaluated by the analysis by the impinger collection.

Note that, in the present embodiment, pipes such as a casing described later and a flow pipe provided in the casing are made of fluororesin (PTFE) unless otherwise specified. In addition, a fluororesin (PFA) pipe was used as a pipe between the processing apparatus 5 and external devices, for example, a particulate removal filter and an exhaust device. Further, a quartz glass tube or a fluororesin (PFA) is applied to each pipe provided for supplying and discharging the solution from the processing apparatus 5, and a fluororesin (PTFE) is used for a connector for connecting the pipes and the like. Applied. Further, since the housing for housing the substrate moves, each pipe connected to the housing is provided with a portion having a flexible tube structure so as not to hinder movement of the housing.

(Example 1) In this example, one housing having an immersion tank was provided, and a silicon wafer was cleaned using an aqueous solution of 1% by weight of hydrofluoric acid and 1% by weight of hydrogen peroxide. . The aqueous solution is particularly suitable for removing Na, Fe, Al, Cu and the like from the surface of the silicon wafer.

FIG. 2 is a cross-sectional view of the processing apparatus provided in the clean booth of FIG. 1 when viewed from a direction parallel to the surface of the silicon wafer 9. The appearance of the fluororesin carrier 10 holding the silicon wafer 9 is shown as it is.

As shown in FIG. 2A, in the processing apparatus 5 according to the present embodiment, a case 13 in which an immersion tank 11 is mounted on a fixed base 12, and a case in which the carrier 10 is held by hooks 14. The cleaning is carried out by uniting the openings 15 and 15 through the openings 16 and 17. The housing 15 is held by a robot arm 18, moves by the operation of a robot (not shown), and is separated from the housing 13 as shown in FIG.

Here, the operation of the processing apparatus shown in FIG. 2 will be described.

First, in a state where the casings 13 and 15 are separated (initial state), the carrier 10 holding the silicon wafer 9 is loaded by hooks 14. Next, the housing 15 moves so as to unite with the housing 13. At this time, the housing 17 moves so that the opening 17 of the housing 15 is located slightly above the opening 16 of the housing 13, and then the housing 15 descends toward the housing 13 and the openings 16 and 17 are closed. The periphery is brought into close contact (start operation). Note that a flow pipe 19 is provided in the housing 15, and prior to the start operation,
The carrier 10 is loaded while introducing high-purity, dust-free air from the flow pipe 19.

On the other hand, in the case 13, the case 1
The atmosphere in the housing 13 is sucked through the flow pipe 20 connected to the housing 3. Then, when the casings 13 and 15 are united, the chemical transport pipe fixing device 2 provided at the bottom of the casing 13
The inside of the immersion tank 11 is filled with the cleaning liquid 25 having the above-mentioned composition from the outside by the chemical liquid transport pipe 22, the joint 23, and the chemical liquid transport pipe 24 in the tank that passes through the pipe 1. Next, the two support columns 27, which are held by the support column holder 26 at the bottom of the housing 13 and can be vertically moved and rotated by 90 °, are raised, and the key portion 28 provided at the distal end is rotated. A not-shown concave portion (see reference numeral 52 in FIG. 4) provided at the upper end of the handle 29 is pushed up by the key of the key portion 28, and the housing 15 is slightly moved so that the carrier 10 can be lowered. Next, the support column 27 is lowered, and the silicon wafer 9 is washed with the cleaning liquid 25 in the immersion tank 11.
For a predetermined time.

After the completion of the cleaning, a rinse liquid (hereinafter abbreviated as HF water) obtained by adding 50 ppm of hydrofluoric acid to ultrapure water is continuously introduced from the chemical liquid transfer pipe 22, and the cleaning liquid overflows from the immersion tank 11. At this time, the electric cock (not shown) of the discharge pipe 30 provided at the bottom of the housing 13 is opened to discharge the overflowing cleaning liquid. Therefore, since the cleaning liquid 25 in the immersion tank 11 is gradually replaced with HF water, the concentration of hydrofluoric acid in the solution gradually decreases, while
H ₂ O ₂ is removed, and the substrate 9 is finally rinsed with HF water. For this reason, the influence of a very small amount of dissolved oxygen and the contamination of the silicon wafer 9 due to the adsorption of a very small amount of metal or the like in the ultrapure water, which are problems when performing general ultrapure water rinsing, are effectively prevented. After the rinsing is completed, the carrier 10 is moved up by the support column 27, the housing 15 is moved in the reverse direction, and the key 28 provided on the support column 27 is operated in the reverse direction.
Is hooked back on a hook 14 provided on the ceiling of the vehicle. At the same time, the rinsing liquid (HF water) in the immersion tank 11 is discharged through the chemical liquid transfer pipe 22.

Finally, the housing 15 is separated from the housing 13 by the operation of the robot and returns to the original position as shown in FIG. 2B (end operation). Here, if the carrier 10 is detached, the entire processing apparatus returns to the initial state.

When the cleaning liquid and the rinsing liquid are used, the rinsing liquid hardly adheres to the carrier and the silicon wafer when the carrier is taken out of the immersion tank due to its properties. Therefore, in the above-described series of operations, hydrofluoric acid that may evaporate from the immersion tank does not leak out of the housings 13 and 15.

In this example, the silicon wafer was immersed for 20 minutes, and during this time, air was sampled and analyzed in the vicinity of the grating 7 as described above. The concentration of hydrofluoric acid was 0.1 ppb or less, which is the detection limit. Met. Therefore, it was confirmed that chemical contamination in the atmosphere in which the processing apparatus was provided was sufficiently prevented.

(Embodiment 2) In this embodiment, as shown in a sectional view in FIG. 3, a housing 15 is provided together with the housing 13 and a housing 45 having the same configuration as the housing 13. The processing equipment was placed in a clean booth. Also,
The cleaning liquid and the rinsing liquid are respectively introduced into the immersion tank 11 and the immersion tank 48 as described later.
The difference between the present embodiment and the first embodiment is that when the silicon wafer is immersed, the position of the silicon wafer is not moved and the housing 15 is not moved.
The immersion tanks 11 and 48 rise inside to immerse the silicon wafer. Further, SC-1 which vigorously emits ammonia gas was used as the cleaning liquid. Here, the composition of SC-1 is ammonia water (28% by weight):
Aqueous hydrogen peroxide (30% by weight): water = 1 volume: 1 volume: 5 volumes, and the liquid temperature during use was 70 ° C.

Here, the operation of the processing apparatus according to this embodiment will be described.

By the same starting operation as in the first embodiment, the housing 15 on which the carrier 10 holding the silicon wafer 9 is mounted is mounted.
The opening 17 is overlapped with the opening 16 of the housing 13 by the movement of the robot arm 18. The fixed base 12 in which the immersion tank 11 is fitted has a built-in heater 31 for heating and keeping the solution warm, and the immersion tank 11 is arranged above and below a support column 33 held by a housing bottom bearing 32. Mechanism (not shown)
And the silicon wafer 9 can be immersed in the immersion tank 11 together with the carrier 10. The support column 33 has a hollow tube structure, and a chemical solution transfer tube 34 is built in the tube structure.

Further, highly purified dust-free air is introduced from the distribution pipe 19, and suction is always performed from the distribution pipe 20. Here, when the casings 13 and 15 are united, the heated cleaning solution (SC-
1) is introduced, and after the cleaning of the silicon wafer 9, the cleaning liquid is discharged by the same transport system. As in the first embodiment, the atmosphere in the environment in which the processing apparatus is disposed during the cleaning of the silicon wafer 9 is changed to ammonia. No contamination. However, in the present embodiment, as shown in FIG. 3A, the opening and closing shielding plates 36 and 37 are provided in the openings 16 and 17 of the housings 13 and 15, thereby improving the productivity of the silicon wafer. And economic efficiency.
Here, FIG. 4 conceptually shows a cross section of the processing apparatus viewed from the front of the substrate.

In the present embodiment, the SC
The supply of -1 is performed when the housing 13 and the housing 15 are not combined (while the housing 15 is at the original position, which is the home position). In order to surely prevent the leakage of the generated ammonia, the exhaust is always performed from the flow pipe 20 and the sliding door-type shield plate 36 provided in the opening 16 is drawn out from the door pocket 38 with a slight gap left. The opening 17 of the housing 15 is provided with the housing 1.
SC-1 that may drop from the silicon wafer 9 and the carrier 10 during the movement of the SC-5 from the top of the housing 13 to the top of the housing 45 is collected, and the SC- attached to the silicon wafer 9 and the carrier 10 is collected. In order to prevent ammonia from scattering from 1 and contaminating the atmosphere in the environment where the apparatus is disposed, the shield plate 37 is of a drawer type, and a flow pipe 40 for constantly exhausting the storage section 39 is connected to the storage section 39.

SC-1 is previously heated to a predetermined temperature.
The silica glass tube 41 is supplied through a quartz glass tube 41, and the quartz glass tube 41 is connected by a connector 42 to a chemical solution transfer tube 34 made of fluororesin (PFA) passing from the preparation tank (not shown) through the inside of the support column 33. Also, the deteriorated SC-1
In this case, the transport system is discarded by flowing backward, and then ultrapure water is supplied to the system to overflow the ultrapure water from the immersion tank 11 to clean each pipe and the inside of the immersion tank 11. The ultrapure water used for cleaning is discharged from the drain port 30.

The flow pipe 19 provided in the housing 15
In addition, since the heater 43 is connected through the connector 44, the silicon wafer 9 and the carrier 10 can be heated while in the original position. In particular, if the dust-free air to be introduced is kept at a liquid temperature of almost SC-1, when the silicon wafer 9 and the carrier 10 are immersed in the SC-1, the liquid temperature of the SC-1 does not decrease and the cleaning is most performed. During about three minutes immediately after the immersion of the silicon wafer 9 where the effect is exhibited, the processing of the silicon wafer 9 can be performed under the optimal temperature condition. In addition, since the supply of the air performed through the distribution pipe 19 is performed through the entire sequence, the consumption amount is considerably large. Therefore, in this embodiment, the atmosphere in the clean booth is highly purified using a purifier (not shown) using a blowing fan and a small-scale filter system, and is introduced into the distribution pipe 19.

Next, the cleaning step using SC-1 will be described. When the housings 13 and 15 are united as shown in FIG. 3A by the start operation, the sliding door 36 is pulled into the door pocket 38 having the closed structure. Next, the carrier 10 is immersed in the SC-1 in the immersion tank 11 from the rising of the support column 33, and is held for a predetermined time (20 minutes in this embodiment).
3 is returned to the original position (the home position shown in FIG. 3), and after the drop of SC-1 from the carrier 10 or the like is no longer confirmed, the drawer-type storage unit 39 having the closed structure is used. The shielding plate 37 is pulled out to close the opening 17. Air entering from the circulation pipe 19 is exhausted to an exhaust duct outside the clean booth through an exhaust port 40 provided at an upper portion of the storage section 39 through a pipe. Next, after closing the opening 16 with a slight gap left by the shielding plate 36, the robot operates to move the housing 15 fixed to the robot arm 18 to the housing 45 in the same manner as the housing 13. Merged.

In the case 45, the air inside the case 45
It is constantly sucked through the distribution pipe 46 and the immersion tank 48
, The silicon wafer 9 is subjected to ultrapure water rinsing → dilute hydrofluoric acid treatment → HF water rinsing. The concentration of dilute hydrofluoric acid can almost completely remove Al and Fe, which are insufficiently cleaned in the natural oxide film removal processing or SC-1 processing generated on the silicon wafer 9, and have a hydrophilic clean surface. It is possible to obtain a silicon wafer that has been used.
At this time, the mechanism for closing the opening provided in the housing 13 is unnecessary, and the effect of preventing contamination by the chemical substance into the atmosphere in which the processing apparatus is provided and the effect of cleaning by the HF water rinse are the same as those in the first embodiment. is there. The structure of the case 45 was the same as the case 13 except for the structure of the opening 47. However, the silicon wafer 9 in the immersion tank 48
Temperature may be about room temperature, so that the immersion tank 48
It is not necessary to provide the heater 31 on the fixing table 49 of the above.

As shown in FIG. 3B, after the housing 15 and the housing 45 are combined,
After the shielding plate 37 provided in 5 is pulled in, the carrier 10 is immersed in the immersion tank 48. The immersion of the carrier 10 in the immersion tank 48 is performed in the same manner as in the case 13 described above.

In processing the silicon wafer 9 in the immersion tank 48, ultrapure water is first supplied into the immersion tank 48 via the transfer pipe 50, and the overflowed ultrapure water and the like are discharged from the drain port 51. You. Specifically, after supplying water about twice the volume of the immersion tank 48 to the immersion tank 48 to overflow the ultrapure water, if the purpose is to remove the natural oxide film, the immersion tank 48 Dilute hydrofluoric acid (hydrofluoric acid: water = 1 volume: about 50 volumes) of substantially the same volume is supplied to the immersion tank 48, and then ultrapure water to which ultrapure water is added with hydrofluoric acid so that the hydrofluoric acid concentration becomes 100 ppm. (HF water) Ultrapure water is supplied to the immersion tank 48 again. By operating in this manner, the concentration of hydrofluoric acid in the solution in the immersion tank 48 gradually decreases, and finally, the concentration of hydrofluoric acid becomes 100 ppm in HF.
Since it becomes water, excellent overflow rinsing that can clean the surface of the silicon wafer is performed.

Next, by the end of the rinsing in the immersion tank 48, the temperature of the dust-free air sent from the flow pipe 19 is reduced to 1
When the temperature is raised to about 00 ° C. and the support column 33 is gradually lowered, the silicon wafer 9 taken out of the immersion tank 48 is dried without being contaminated. And support pillar 3
After returning to the original position, the housing 15 is returned to the original position, the carrier is detached, and the cleaned silicon wafer is collected.

Here, it is desirable to employ an automatic mechanism for attaching and detaching the carrier 10 from the housing 13. As this mechanism, as shown in the first embodiment, a carrier delivery mechanism by vertical rotation of the keyed support column and horizontal fine movement of the housing may be provided at the original position shown in FIG. In this case, the carrier 10 needs a recess 52 for locking the support column shown in FIG.

In this embodiment, the silicon wafer SC
During the -1 washing, the air was sampled in the vicinity of the grating 7 as described above and analyzed by ion chromatography, and the concentrations of ammonia and hydrofluoric acid were below the detection limit of 0.1 ppb or less. Therefore, it was confirmed that chemical contamination in the atmosphere in which the processing apparatus was provided was sufficiently prevented.

[0058]

As described in detail above, according to the processing apparatus of the present invention, the immersion tank is housed so as to be exposed through the first opening, and the immersion tank is located in the area where the immersion tank is housed. A first flow pipe having a first flow pipe for flowing the first gas;
And a substrate immersed in the immersion tank are stored so as to be exposed through a second opening that can be in close contact with the first opening, and a second gas is supplied to an area where the substrate is stored. And a second housing provided with a second circulation pipe for distributing the first fluid through the first and second openings.
And the second housing are united, and while the first and second gases are circulated through the first and second flow pipes, the substrate can be immersed or pulled up into the immersion tank. Prevents contamination of the atmosphere in the clean draft by various gases and mist generated from the tanks, etc., and contributes to maintaining the cleanliness of the entire clean room. By executing the sequence of the immersion process while isolating, the contamination of the substrate and the like can be significantly reduced, and the production yield of various devices can be improved.

Further, according to the processing apparatus of the present invention, the first immersion tank is housed so as to be exposed through the first opening, and the first immersion tank is placed in the area where the first immersion tank is housed. A first housing provided with a first flow pipe for flowing gas and a second immersion tank were housed so as to be exposed through the second opening, and the second immersion tank was housed. A second flow pipe provided with a second flow pipe for flowing a second gas through the region;
And a substrate immersed in the first and second immersion tanks are stored so as to be exposed through a third opening that can be in close contact with the first and second openings, and the substrate is stored therein. The first and third openings or the second and third openings by providing a third housing provided with a third flow pipe for flowing the third gas through the region. Through the first and third housings or the second and third housings, and through the first and third flow pipes or the second and third flow pipes, the first and third gases or Since the substrate can be immersed or pulled into the first or second immersion tank while flowing the second and third gases, various gases generated from the first and second immersion tanks and the like can be used. Prevents contamination of the atmosphere in the clean draft by In addition to contributing to maintaining the cleanliness of the entire clean room, the sequence of the immersion process is continuously performed while isolating the clean substrate after rinsing from the gas or mist, thereby significantly reducing the contamination of the substrate, etc. It is possible to realize an improvement in production yield. That is, in the processing apparatus according to the present invention, a processing apparatus capable of almost certainly preventing two or more types of chemical processing on a substrate such as a silicon wafer from being contaminated in a clean room environment in which the processing apparatus is disposed. Can be provided. According to the processing apparatus of the present invention, for example, it is particularly effective for an essentially paired cleaning sequence such as a combination of cleaning with a chemical solution and rinsing with pure water.

Further, according to the processing apparatus of the present invention, the immersion tank, the first and second casings forming a space in which the immersion tank is sealed and being separable from each other, and at least the space By providing the first and second flow pipes disposed in the first and second housings so that gas flows therethrough, the first and second flow pipes allow the gas to flow into the space through the first and second flow pipes. It is possible to immerse or lift a processing object represented by a substrate or the like into an immersion tank while circulating the first and second gases, so that it can be cleaned by various gases or mist generated from the immersion tank or the like. Prevents the contamination of the draft atmosphere and contributes to maintaining the cleanliness of the entire clean room, and at the same time, executes a sequence of immersion processing while isolating the cleaned substrate from the gas and mist to significantly contaminate the substrate and the like. Reduced, various It is possible to realize an improvement of the device of the production yield.

Therefore, according to the cleaning apparatus of the present invention, regarding wet cleaning and etching, a draft having a forced exhaust system is installed in a clean room, and the processing apparatuses are arranged in the draft, so that extremely environmental pollution is prevented. It is not necessary to adopt a configuration that is likely to occur.

The clean surface of the substrate or the like after the cleaning process has a property of adsorbing organic substances and acids in the environment in a very short time. In the processing apparatus according to the present invention, it is possible to perform processing after rinsing the substrate while substantially preventing chemical contamination from the atmosphere in the environment. Therefore, it is possible to provide a processing apparatus capable of performing processing with less contamination of a substrate or the like by a metal or an organic substance even in a normal clean room in which a countermeasure against chemical contamination is not taken, that is, in a clean room without a chemical filter or the like.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a clean booth in which a processing apparatus of the present invention is installed.

FIG. 2 is a cross-sectional view of the processing apparatus when viewed from a direction parallel to a surface of a silicon wafer 9;

FIG. 3 is a cross-sectional view of the processing apparatus when viewed from a direction parallel to a surface of a silicon wafer 9;

FIG. 4 is a view conceptually showing a cross section of the processing apparatus viewed from the front of the substrate.

[Explanation of symbols]

1a, 1b ... anion exchange fiber filter 2a, 2b ... cation exchange fiber filter 3 ... ULPA filter 4 ... fan 5 ... processing unit 6 ... side wall 7 ... grating 8 ... transparent plastic door 9 ... ... Silicon wafer
DESCRIPTION OF SYMBOLS 10 ... Carrier 11 ... Immersion tank 12 ... Fixing base 13 ... Case
14 ... hook 15 ... housing 16 ... opening 17 ... opening 18 ... robot arm 19 ... flow pipe 20 ...
… Circulation pipe 21… Chemical liquid transport tube fixture 22 …… Chemical liquid transport pipe
23 joint 24 chemical transfer pipe in tank 25 cleaning liquid 26
... Support column holder 27 ... Support column 28 ... Key part 29 ... Carrier handle 30 ... Discharge tube 31 ... Heating device 32 ... Housing bottom bearing 33 ... Support column 34 ... Chemical solution transfer tube 36 ... … Shielding plate 37 …… Shielding plate 38 …… Door bag 39 …… Storage part
40: Distribution tube 41: Quartz glass tube 42: Connector 43
... Heating device 44 ... Connector 45 ... Housing 46 ... Flow pipe 47 ... Opening part 48 ... Immersion tank 49 ... Fixing table 50 ... Transport pipe 51 ... Waste liquid port 52 ... Recess

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Akira Yoneya 1-8-4 Okubo, Narashino City, Chiba Prefecture

Claims (6)

[Claims] A first immersion tank is stored so as to be exposed through a first opening, and a first circulation pipe for circulating a first gas through an area in which the immersion tank is stored. 1 housing, and a substrate immersed in the immersion tank is housed so as to be exposed through a second opening which can be in close contact with the first opening, and a second housing is provided in an area where the substrate is housed. A second housing provided with a second circulation pipe for allowing the gas to flow therethrough. 2. When the first and second housings are joined by the close contact of the first and second openings, the immersion tank moves to immerse the substrate with respect to the substrate. The processing device according to claim 1, wherein: 3. The processing apparatus according to claim 1, wherein at least one of the first and second openings further includes means for closing the opening. 4. The processing apparatus according to claim 1, wherein the second flow pipe further includes a means for heating a gas. 5. A first immersion tank which is housed so as to be exposed through a first opening, and a first gas for flowing a first gas through an area where the first immersion tank is housed. A first housing provided with a flow pipe and a second immersion tank are housed so as to be exposed through a second opening, and a second gas is supplied to a region where the second immersion tank is housed. A second with a second distribution tube for distribution
And a substrate immersed in the first and second immersion tanks are housed so as to be exposed through a third opening that can be in close contact with the first and second openings, and the substrate is A processing apparatus, comprising: a third housing provided with a third flow pipe for flowing the third gas through the accommodated region. 6. An immersion tank, first and second housings which form a space in which the immersion tank is hermetically sealed and which can be separated from each other; A processing apparatus comprising: first and second flow pipes disposed in first and second housings.