JP2008141080A - Wafer container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer container capable of efficiently removing contamination gas which has an adverse effect on a semiconductor wafer out of the space in a container with simple, non-bulky, and inexpensive configuration, and capable of selectively and effectively performing contamination gas removal so as to correspond to use environments. <P>SOLUTION: At least one kind of chemical absorber 19 for adsorbing specific gas component is arranged over almost entire range, expanding in the axial direction of a plurality of semiconductor wafers W, in at least one space which is formed with an inside wall space of a lid 2 and a wafer support body 7. The chemical absorber is attached to the wafer support body 7 by an absorber hooking part 18 formed at reinforcing frames 15 and 16 of the chemical absorber 19. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wafer storage container used for storing and transporting and storing a plurality of semiconductor wafers in a clean environment isolated from the external environment.

In general, a wafer storage container is provided with a container main body and a lid that hermetically closes the opening of the container main body, and a plurality of semiconductor wafers are stored in a completely sealed state isolated from the external environment. Can be. However, due to environmental factors inside and outside the container, various gases (hereinafter, referred to as “organic gas component”, “acid gas component”, “alkaline gas component”, etc.) that may adversely affect the semiconductor wafer in the air inside the container. "Contaminated gas"). Therefore, conventionally, a fan motor for arranging a chemical absorber for adsorbing a pollutant gas in a container (for example, Patent Documents 1 and 2) or for forming a circulating airflow in the container in addition to the chemical absorber. Etc. (Patent Document 3).
Japanese Patent No. 3336652 JP 2004-260087 A JP 2001-77188 A

  However, even if the chemical absorber is disposed at an appropriate position in the container as in the inventions described in Patent Documents 1 and 2, the contaminated gas in the container cannot be efficiently adsorbed and removed. The effect of preventing adverse effects on the semiconductor wafer has been limited. In addition, when a fan motor or the like for forming a circulating airflow is arranged in the container as in the invention described in the cited document 3, the contaminated gas in the container can be efficiently adsorbed and removed. Since the structure of the container becomes large, it becomes very difficult to handle and at the same time, the cost is greatly increased. In addition, since the types of chemical absorbers used in conventional wafer storage containers have not been scrutinized according to the usage environment, there are few cases where only a part of various polluted gases contained in the container can be adsorbed and removed. There wasn't.

  The present invention can efficiently remove pollutant gases that adversely affect semiconductor wafers from the space in the container with a simple and low-cost configuration, and further, such pollutant gas removal can be used in a use environment or the like. It is an object of the present invention to provide a wafer container that can be selectively and effectively performed.

  In order to achieve the above object, the wafer storage container of the present invention airtightly closes the container body for storing a plurality of semiconductor wafers and an opening formed on one surface of the container body via a seal. A lid that is detachably attached to the container body, a wafer support that supports a plurality of semiconductor wafers in the container body at predetermined intervals in the axial direction, and an outer edge of the plurality of semiconductor wafers. A concave portion formed in the axial direction of the plurality of semiconductor wafers in the region of the inner wall surface of the lid body and a concave portion disposed in the concave portion so as to press and fix the plurality of semiconductor wafers in cooperation with the wafer support. In a wafer storage container having a wafer holding member, at least one chemical absorber for adsorbing a specific gas component is a gap between the container body and the wafer support. In which they are arranged over substantially the entire range of axial direction in the serial plurality of semiconductor wafers.

  In addition, it is preferable that the wafer support is formed with a vent hole for substantially the entire area to ensure ventilation between the space in which the chemical absorber is arranged and the space in which the semiconductor wafer is arranged.

Further, a reinforcing frame may be provided along the entire outer edge of the chemical absorber.
Further, the chemical absorber disposed in the space formed by the container main body and the wafer support may be regulated by the wafer support itself from being detached from the space. Or the absorber latching | locking part for latching a chemical absorber to a wafer support body may be formed in the said reinforcement frame.

  According to the present invention, the space in the recess formed in the inner wall surface of the lid is partitioned by the wafer pressing member disposed therein, and the chemical absorber is disposed in the space, thereby the wafer storage container. Can be made a simple and low-cost configuration. In addition, the recesses in which the chemical absorbers are arranged are formed so as to extend in the axial direction of a plurality of semiconductor wafers, thereby efficiently removing pollutant gases that adversely affect the semiconductor wafers from the space in the container. Can do. Moreover, as a chemical adsorbent used for a chemical absorber, an organic gas chemical adsorbent that adsorbs a predetermined organic gas component, an acidic gas chemical adsorbent that adsorbs a predetermined acidic gas component, and a predetermined alkaline gas component are adsorbed. By selecting one or more of the alkaline gas chemical adsorbents, it is possible to selectively and effectively remove the pollutant gas in accordance with the environment of use.

Embodiments of the present invention will be described below with reference to the drawings.
1 is a side sectional view of the wafer storage container, FIG. 2 is a perspective view showing the inside of the wafer storage container, and FIG. 3 is a partial front sectional view of the container main body.

  Reference numeral 1 shown in each figure denotes a container body made of a plastic material that generates relatively little pollutant gas, such as polycarbonate. The container body 1 is sized to accommodate a plurality (25 in this embodiment) of semiconductor wafers W, and is formed in a shape having only an upper surface or a side surface opened. A pair of wafer supports 7 that can support a plurality of semiconductor wafers W in an aligned state with a certain interval therebetween in the axial direction are opposed to each other inside the container body 1. It is arranged along the inner wall surface. On each wafer support 7 formed of a plastic material, for example, 25 wafer support grooves 8 having a V-shaped cross-sectional shape for placing the semiconductor wafer W are formed at equal intervals. The bottom of the container body 1 that exists between the pair of wafer supports 7 and faces the opening is a space. The configuration of the wafer support 7 is not limited to this embodiment.

  A lid 2 is detachably attached to the opening of the container body 1. In a state where the lid 2 is attached to the container body 1, the opening of the container body 1 is hermetically closed by the sealing material 3 formed in an annular shape with a resilient member, and the inside of the wafer storage container is externally Completely sealed, isolated from Although the sealing material 3 is attached to the lid 2 in this embodiment, the sealing material 3 may be formed by the lid 2 itself, or the sealing material 3 may be provided on the container body 1 side. Absent. As is known by the standards of the International Semiconductor Manufacturing Equipment Material Association, a wafer storage container that can be automatically opened and closed by a mechanical device is a diagram for locking the lid 2 to the container body 1. It has a pair of latch mechanisms not shown. Each of these latch mechanisms is arranged at a position near the outer edge in the lid body 2 so as to pass through the lid body 2 straight, and the lid body 2 is formed with a thickness sufficient to incorporate the latch mechanism.

  On the inner wall surface (that is, the back surface) of the lid body 2, a recess 4 is formed at a position between thick portions where a pair of latch mechanisms (not shown) are arranged, and this portion is the thickness of the lid body 2. Is thinner. The recess 4 is formed with a uniform width on both sides of the center line of the lid 2 so as to face the outer edges of the plurality of semiconductor wafers W held perpendicular to the bottom surface of the container body 1 from above. The bottom surface is a plane having a certain depth. The recess 4 extends straight in the axial direction of the plurality of semiconductor wafers W as shown in FIG. 1 and is formed in a rectangular shape with both ends adjacent to the inside of the sealing material 3. The size is opposite to the outer edge of the entire wafer W.

  Such a recess 4 is made of a plastic material or the like for elastically pressing and fixing all the semiconductor wafers W from above in cooperation with a pair of wafer supports 7 arranged in the container body 1. A wafer pressing member 5 is disposed. A pair of wafer pressing members 5 of this embodiment are arranged on both sides of the center line in the longitudinal direction of the concave portion 4 and are arranged in a pair, and are elastic or have locking projections (not shown) formed on the lid 2. Or the like) so as to be separable from the lid body 2. The portions other than the vicinity of the base of each wafer pressing member 5 are divided into elongated and even portions with a gap in the axial direction of the semiconductor wafer W by a slit (not shown) corresponding to the wafer support groove 8 of the wafer support 7. . In this embodiment, each wafer pressing member 5 is divided into 25 by slits.

  The pair of wafer pressing members 5 is formed in a shape that divides the space in the recess 4 formed on the inner wall surface of the lid 2 into three regions extending in the axial direction of the plurality of semiconductor wafers W. Specifically, each wafer pressing member 5 forms a rectangular space between the half part near the base and the bottom surface of the recess 4, and the bottom half of the recess 4 further between the half parts near the tip. Are bent into a shape that forms a third space between them. A half of the wafer pressing member 5 near the tip protrudes to a position where it touches the semiconductor wafer W, and the semiconductor wafer W is fitted into a wafer pressing groove 6 having a V-shaped cross section formed therein, thereby The member 5 is pressed against the semiconductor wafer W and is elastically deformed.

  On the other hand, as shown in FIGS. 1 and 3, chemical absorbers 9 and 10 are disposed in at least one of the two spaces formed by being surrounded by the container body 1 and the wafer support 7. Has been. As shown in FIG. 1, the chemical absorbers 9 and 10 are disposed over substantially the entire region where the semiconductor wafer W is disposed extending in the axial direction of the semiconductor wafer W. The chemical absorbers 9 and 10 are an organic gas chemical adsorbent that adsorbs a predetermined organic gas component, an acidic gas chemical adsorbent that adsorbs a predetermined acidic gas component, and an alkaline gas adsorbed a predetermined alkaline gas component. It is a chemical absorber using at least one kind of chemical adsorbent. In this embodiment, a case where two chemical absorbers are arranged in total, two in one space and two in the other space has been shown. However, if it is possible to ensure predetermined gas adsorption characteristics One may be arranged in both spaces, or only one in one space. The wafer support 7 is formed with vent holes for ensuring ventilation between the space in which the chemical absorbers 9 and 10 are disposed and the space in which the semiconductor wafer W is disposed. Specifically, in this embodiment, a slit for dividing each wafer support 7 is a vent hole. A fan motor and other devices for circulating the air in the wafer storage container are not provided at all.

  FIG. 4 shows a specific configuration of the wafer support 7. FIG. 4 is a perspective view showing the configuration of the wafer support. The wafer support 7 is mainly composed of fins 13 extending in the peripheral direction of the semiconductor wafer W and aligned in the axial direction thereof, and coupling portions 14 that connect these fins 13. The space surrounded by 14 is a slit. The coupling portion 14 located at the bottom is cut into a V-groove shape by a slit, which forms a wafer support groove 8. In addition, a pair of upper locking portions 11 is formed on the side of the coupling portion 14 positioned at the top, and a pair of lower locking portions 12 is formed on the side of the coupling portion 14 positioned at the bottom. The upper locking portion 11 and the lower locking portion 12 formed on the wafer support 7 are engaged with locking grooves (not shown) provided on the inner side surface of the container main body 1 so that the wafer support 7 is placed in the container. It acts to attach to the main body 1.

  As the chemical absorber, effective impurity gas adsorption can be performed by appropriately arranging a chemical adsorbent for acidic gas, a chemical adsorbent for alkaline gas, and a chemical adsorbent for organic gas. In other words, by placing the organic gas chemical adsorbent between the acid gas chemical adsorbent and the alkali gas chemical adsorbent, the acid gas chemical adsorbent and the alkaline gas chemical adsorbent interact with each other. Giving can be prevented. In addition, as a gas adsorbent for organic gas chemical adsorbents, for example, activated carbon or the like can be used to adsorb and remove gases composed of organic substances such as aromatic hydrocarbons, siloxane components, alcohols, and esters. The activated carbon may be obtained by putting activated carbon powder in a non-woven bag or the like, but it is convenient to use an activated carbon sheet processed into a sheet. As the activated carbon sheet, it is possible to use a fibrous activated carbon itself made into a nonwoven fabric, or a material in which powdered activated carbon is added to the nonwoven fabric in the process of forming a nonwoven fabric sheet.

  As a gas adsorbent for a chemical adsorbent for acidic gas, for example, an adsorbent in which an alkaline compound such as potassium carbonate is attached to activated carbon is used to adsorb a gas composed of an acidic substance such as nitric acid, sulfuric acid, hydrochloric acid, and phosphoric acid. Can be removed. Further, as a gas adsorbent for an alkaline gas chemical adsorbent, for example, an adsorbent in which an acidic compound such as phosphoric acid is attached to activated carbon is used to adsorb and remove a gas composed of an alkaline substance such as ammonia or amines. be able to. Further, as the adsorbent, in addition to activated carbon, metal fibers subjected to surface activation treatment, ceramic adsorbent, and the like can be used.

  FIG. 12 shows the analysis result by the gas chromatography mass spectrometer of the experiment conducted for confirming the effect of removing the pollutant gas in the wafer storage container according to the above embodiment. For comparison, the same conditions apply when the chemical absorbers 9 and 10 are not used (FIG. 13) and when the chemical absorbers 9 and 10 are arranged at one location in the radial direction of the semiconductor wafer W (FIG. 14). The experiment was conducted. Before the experiment, the wafer storage container was opened in the lid 2 and stored in a room with a high organic concentration (that is, a room in a normal building) for a week. In the clean room, 25 wafers W having a diameter of 30 cm, the chemical absorber 9 and 10 was set. Then, the lid 2 was closed and left for 3 days, and then the air in the wafer storage container was sampled using a Tenax tube and analyzed by a gas chromatography mass spectrometer. As a result, it was confirmed that the contamination gas in the wafer storage container is remarkably reduced by arranging the chemical absorbers 9 and 10 as shown in the above-described embodiment as shown in FIGS. In this way, if all three types of chemical adsorbents, organic gas chemical adsorbent, acidic gas chemical adsorbent, and alkaline gas chemical adsorbent, are arranged, most of the polluted gases can be adsorbed and removed. By selecting one or a plurality of chemical adsorbents according to the usage environment of the storage container, the pollutant gas can be adsorbed and removed efficiently and effectively.

  Each chemical absorber 19 arranged in the wafer storage container as described above is surrounded by a porous membrane filter (membrane filter) through which gas passes but solid particles do not pass and is sealed inside. Is preferred. By doing so, it is possible to prevent the gas adsorbing material forming the chemical absorber from diffusing out of the chemical absorber, and at the same time, the adsorption function of the gas adsorbing material is deteriorated by particulates other than gas in the air. Can be prevented. As such a membrane filter, a tetrafluoroethylene resin-based porous film such as PTFE or PFA can be used, and the thickness can be extremely thin, for example, about 0.02 to 0.05 mm. it can.

  FIG. 7 schematically shows a state in which the chemical adsorbent is surrounded and sealed with such membrane filters 20 and 21, where the chemical adsorbents 22, 23, and 24 divided into three are the same. The two membrane filters 20 and 21 are arranged on the surface in a sandwich shape. The three chemical adsorbents 22, 23, and 24 may be the same type of filter, but may be different types of filters. Then, as shown in FIG. 8, the two membrane filters 20 and 21 overlapped with each other are fused to each other at the outer edge portion and the portion between the chemical adsorbents 22, 23 and 24. The adsorbent is sealed inside the membrane filter. At this time, the membrane filter 20 is divided into three parts 20a, 20b, and 20c to function. Reference numeral 25 denotes a fused portion.

  FIG. 9 shows three chemical adsorbents: an organic gas chemical adsorbent 27, an acidic gas chemical adsorbent 26, and an alkaline gas chemical adsorbent 28, and an acidic gas chemical adsorbent 26 and an alkaline gas chemical adsorbent 28. And schematically show a state where the organic gas chemical adsorbent 27 is sandwiched and disposed. Thus, by stacking the three types of chemical adsorbents 26, 27, and 28, the area efficiency is improved, and the organic gas chemical adsorbent 27 is converted into an acidic gas chemical adsorbent 26 and an alkaline gas chemical adsorbent 28. Therefore, the acidic gas chemical adsorbent 26 and the alkaline gas chemical adsorbent 27 can be prevented from causing a chemical reaction with each other. Also in this case, as shown in FIG. 9, a porous membrane filter 20 through which gas passes but solid particles do not pass through the three types of stacked chemical adsorbents 26, 27, and 28. The outer peripheral portions of the membrane filters 20 and 21 may be fused all around as shown in FIG. Reference numeral 25 denotes a fused portion, and the effect thereof is as described above. As shown in FIG. 13, each of the three types of chemical adsorbents is divided into a plurality of pieces in the longitudinal direction to form 26a, 26b, 27a, 27b, and 28a, 28b, and the divided pieces are stacked to form a membrane filter. You may make it seal in 20 and 21. FIG.

  In order to keep the chemical absorber 19 in a stable state in the space formed between the container body 1 and the wafer support 7, as shown in FIG. 5, a membrane filter surrounding the chemical adsorbent. Reinforcing frames 15 and 16 made of, for example, a plate-like plastic material may be provided along the fusion part at the outer edge of the plate. When adopting a configuration in which the fused portion of the chemical absorber 19 is sandwiched between the pair of reinforcing frames 15 and 16, it is possible to form the engaging pins 17a and the engaging holes 17b that fit tightly in the reinforcing frames 16 and 15, respectively. Can be easily assembled. Of the two reinforcing frames, the reinforcing frame 16 facing the inner wall of the container body 1 may be formed in a plate shape facing the entire surface of the membrane filter. The two reinforcing frames are provided with openings so that the chemical absorber is exposed to the environment.

  Further, as shown in FIGS. 8 and 9, an absorber locking portion 18 for locking the chemical absorber 19 may be formed on the reinforcing frame. The absorber locking portion 18 of the present embodiment has a snap structure with a hook for preventing removal, and the upper locking portion 11 or the lower locking portion 12 provided on the wafer support 7 shown in FIG. And can be detachably attached to the wafer support 7.

  The present invention is not limited to the above-described embodiment. For example, the shape of the wafer support 7 may be any shape, and a plurality of semiconductor wafers W are cooperated with the wafer pressing member 5. In which an air passage is formed to ensure air flow between the space in which the chemical absorbers 9 and 10 are disposed and the space in which the semiconductor wafer W is disposed. I just need it.

It is side surface sectional drawing of the wafer storage container which concerns on this invention. It is a perspective view which shows the internal arrangement | positioning of the wafer storage container which concerns on this invention. It is a partial front sectional view of a wafer storage container concerning the present invention. It is a perspective view which shows the wafer support body of the wafer storage container which concerns on this invention. It is a disassembled perspective view which shows the reinforcement structure of the chemical absorber which concerns on this invention. It is a perspective view which shows the reinforcement structure of the chemical absorber which concerns on this invention. It is a disassembled perspective view of the chemical absorber which concerns on this invention. It is a perspective view of the chemical absorber which concerns on this invention. It is a disassembled perspective view of the chemical absorber which concerns on this invention. It is a perspective view of the chemical absorber which concerns on this invention. It is a disassembled perspective view of the chemical absorber which concerns on this invention. It is a diagram which shows the analysis result of the residual gas after the experiment which confirms the effect of the pollutant gas removal by the wafer storage container which concerns on this invention. It is a diagram which shows the analysis result of the residual gas after an experiment at the time of omitting a chemical absorber, in order to contrast with the effect of the pollutant gas removal by the wafer storage container which concerns on this invention. It is a diagram which shows the analysis result of the residual gas after an experiment at the time of arrange | positioning a chemical absorber in parallel with the surface of a semiconductor wafer, in order to contrast with the effect of the pollutant gas removal by the wafer storage container which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Container main body 2 Cover body 3 Sealing material 4 Recessed part 5 Wafer holding member 7 Wafer support 9, 10 Chemical absorber 15, 16 Reinforcement frame 18 Absorber latching part 20, 21 Membrane filter 25 Fusion part 26 Chemical adsorption for acid gas Agent 27 Chemical Adsorbent for Organic Gas 28 Chemical Adsorbent for Alkaline Gas W Semiconductor Wafer

Claims (4)

A container body for storing a plurality of semiconductor wafers, and a lid body detachably attached to the container body so as to hermetically close an opening formed on one surface of the container body through a seal; A wafer support for supporting the plurality of semiconductor wafers at predetermined intervals in the axial direction in the container body, and an area of the inner wall surface of the lid facing the outer edge of the plurality of semiconductor wafers. A recess formed in a direction substantially perpendicular to the surface of the plurality of semiconductor wafers, and disposed in the recess so as to press and fix the plurality of semiconductor wafers in cooperation with the wafer support. In a wafer storage container having a wafer holding member made,
That at least one chemical absorber for adsorbing a specific gas component is disposed over substantially the entire axial range of the plurality of semiconductor wafers in the gap between the container body and the wafer support. A wafer storage container.   2. The wafer according to claim 1, wherein the wafer support is formed with vent holes for substantially ensuring ventilation between the space in which the chemical absorber is disposed and the space in which the semiconductor wafer is disposed. Storage container.   A reinforcing frame is provided along the entire outer edge of the chemical absorber, and an absorber locking portion for locking the chemical absorber to the wafer support is formed in the reinforcing frame. The wafer storage container according to any one of the above.   4. The wafer storage container according to claim 3, wherein the reinforcing frame has an opening for exposing the chemical absorber at least on a surface of the semiconductor wafer.

Images