JP2007256011A - Inspection method of ion exchange resin or ultrafiltration membrane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection method of an ion exchange resin or an ultrafiltration membrane capable of simply and rapidly judging the quality of the ion exchange resin or the ultrafiltration membrane immediately before delivery in a washing factory. <P>SOLUTION: Ultrapure water, from which dissolved oxygen is removed, is supplied to and passed through a column filled with the ion exchange resin being a specimen or an ultrafiltration membrane filter device and column outflow water from the column is supplied to a wafer holder loaded with a wafer to be brought into contact with the wafer and the surface state of the water after contact is measured to judge the quality of the ion exchange resin or the ultrafiltration membrane as the specimen. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an inspection method for ion exchange resins or ultrafiltration membranes used in an ultrapure water subsystem for semiconductor manufacturing, and in particular, it is possible to inspect product quality immediately before shipment in a resin washing factory. The present invention relates to a method for inspecting an ion exchange resin or an ultrafiltration membrane.

  The quality of the ion exchange resin used in the ultrapure water manufacturing subsystem for semiconductor manufacturing is inspected as follows. That is, the above-described ion exchange resin is washed at a resin washing plant, and then a part thereof is taken out and ultrapure water is passed through in a state where the ion exchange resin is filled in a filling container of the ion exchange resin. And the TOC value and resistivity are measured about the ultrapure water at the time of water flow, and it is within the range of 1-10 microgram / l according to grade as an elution TOC value, and it is 15-18 Mohm * cm or more as a resistivity. After confirming that, an ion exchange resin satisfying such acceptance criteria was shipped as a product. However, since the above inspection method at the time of shipment was only the TOC value and the resistivity, it was not possible to evaluate how much the ion exchange resin affects the semiconductor product.

  For this reason, with the conventional inspection method at the time of shipment, even if the ion exchange resin is shipped after confirming that the acceptance standard is satisfied, the quality standard will not meet the rapid performance improvement of recent semiconductor products. I came. One of the causes is that recent semiconductor products have a thin oxide film thickness, which is about several nm to several tens of nm. This tendency is prominent in factories that manufacture system LSIs, particularly flash memory. Specifically, ultra-trace organic substances are eluted from a new ion-exchange resin after replacement, and the wafer surface is roughened by the ultra-trace organic substances. As a result, the oxide film (interlayer insulating film) formed on the wafer surface loses its flatness, the IV characteristics and the breakdown voltage are poor, and the product cannot be manufactured for 1 to 6 months. Has become more frequent in recent years.

In JP-A-5-264524, as an ion exchange resin evaluation method, pure water is passed through a column packed with an ion exchange resin as an analyte, and the effluent is brought into contact with the wafer and adsorbed on the wafer. A method for analyzing the impurity atoms is disclosed. Japanese Patent Application Laid-Open No. 2003-334550 discloses an ammonium polymer (hereinafter referred to as “PSQ”) such as polytrimethylbenzylammonium salt or polytrimethylstyrylalkylammonium salt as a wafer contaminant eluted from an ion exchange resin, and PSQ and polystyrene. Complexes with sulfonic acid (hereinafter referred to as “PSA”) are mentioned.
JP-A-5-264524 However, the target substance to be evaluated is completely analyzed from the analysis of impurities adsorbed on the wafer and the water quality analysis of the treated water of the ion exchange resin or the ultrafiltration membrane for the influence on the semiconductor product. There are many cases where it is not known. And there are many kinds of organic substances that have a high possibility of affecting the quality of semiconductor products, and it is difficult to specify them, and the amount contained in ultrapure water is as small as ng / l order. In this way, even if the main contamination source is PSQ or PSA, the content is at the analysis lower limit level. Therefore, in the evaluation method for measuring PSQ or PSA, an ion exchange resin is used in a resin washing plant. Immediately before shipping as a product, it is extremely difficult to easily and quickly determine the quality of the ion exchange resin.

  As described above, the semiconductor products are frequently troubled by the ultra-trace organic matter from the new ion exchange resin. It is considered that the cleaning of the ion exchange resin has a great influence as a cause of such a malfunction of the semiconductor product. And it is highly possible that the causative substance causing the above-mentioned problem is a substance (PSQ or PSA) eluted from the ion exchange resin. The inventors also assumed a compound having an amino group in the benzene ring skeleton and a molecular weight of about 150 to 600 as a substance causing such a malfunction. Specifically, not only low-molecular amines such as monomethylamine, dimethylamine, and trimethylamine, which are main compounds eluted from anion exchange resins, but also high-molecular hydrophobic amines are considered to be the substances causing the above-mentioned problems. It is done. Similarly, it is considered that a trace amount of trouble-causing substances are eluted from the ultrafiltration membrane.

  The present invention has been made in view of the above-described circumstances, solves the above-described conventional problems, and can easily and quickly determine the quality of the ion exchange resin immediately before shipment at a resin washing factory. It aims at providing the inspection method of an ion exchange resin or an ultrafiltration membrane.

  Therefore, the present inventors established a method for indirectly evaluating the presence or absence of a substance that causes this surface roughness using a silicon wafer as an inspection method before shipment at a stage close to the product. That is, the above object is achieved by the invention described in each claim of the present application.

  An invention of an inspection method for an ion exchange resin or ultrafiltration membrane used in an ultrapure water subsystem for manufacturing a semiconductor according to claim 1 of the present invention is a column or an analyte packed with an ion exchange resin as an analyte. Supply ultra-pure water from which dissolved oxygen is removed to a device loaded with an ultrafiltration membrane as a column, and let the column effluent flowing out of the column come into contact with the wafer, and the surface state of the wafer after contact The quality of the ion exchange resin as the subject or the ultrafiltration membrane as the subject is determined by measuring the above.

According to a second aspect of the present invention, in the first aspect of the invention, the wafer surface state is measured by means of measuring the average roughness Ra value (nm) and the maximum height difference Rmax (nm) of the wafer surface roughness. Made by
Formula (1): Ra value ≦ allowable reference value A
And the following equation (2): Rmax value ≦ allowable reference value B
The Ra value and the Rmax value, which are the determination values, are compared with the allowable reference values set in advance with non-defective products based on the determination formula shown by, and whether or not the determination values are equal to or less than the allowable reference values A and B, respectively. Thus, the quality of the ion exchange resin as the subject or the ultrafiltration membrane as the subject is determined.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, as the wafer, an inclination angle with respect to the (100) plane of the ingot from the n-type, p-type, and silicon single crystal ingots. Any one of bare silicon wafers cut out with a thickness of 1 is used.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the water is passed through a column packed with the ion exchange resin or an apparatus loaded with an ultrafiltration membrane as an analyte. As the ultrapure water, ultrapure water having a dissolved oxygen concentration of 100 μg / l or less is used.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the effluent water from the device loaded with the column or the ultrafiltration membrane is brought into contact with a wafer filled in a wafer holder. It is characterized by that.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the effluent water from the apparatus loaded with the column or the ultrafiltration membrane is transferred to the wafer holder in the wafer cleaning tank. The wafer is placed in contact with the wafer.

  According to the inspection method of the present invention, by replacing the ion exchange resin or the ultrafiltration membrane of the subsystem with the ion exchange resin or the ultrafiltration membrane that has been accepted, the LSI is replaced after one day after the replacement. Even when production of a product or the like is started, the rate at which defective products are produced can be greatly reduced.

  In addition, the inspection method of the present invention can easily and quickly determine the quality of the ion exchange resin or the ultrafiltration membrane. Therefore, according to the present invention, not only can the product quality be inspected immediately before the shipment in the resin / film cleaning factory, but also the quality inspection is suitably performed in the customer semiconductor factory where the product is shipped. be able to.

  FIG. 1 shows an example of a schematic configuration of an ion exchange resin inspection apparatus configured to carry out the inspection method of the present invention. This apparatus includes a degassing membrane device 1, a resin column 2, and a wafer holder 3.

  In this figure, when the degassing membrane apparatus 1 introduces ultrapure water into the wafer holder 3 through the column 2, the dissolved oxygen (DO) is reduced to 100 μg / l or less to suppress the growth of a natural oxide film on the wafer surface. To be provided. The deaeration membrane device 1 is connected to the pipeline 11 and the pipeline 12, and ultrapure water flowing from the pipeline 11 into the deaeration membrane device 1 is deaerated and introduced into the column 2 through 12. Is done. The column 2 is packed with an ion exchange resin 4 which is an analyte. Ultrapure water that has contacted the ion exchange resin in the column 2 is introduced into the wafer holder 3 from the conduit 21, contacts the wafer 5 mounted in the wafer holder 3, and is taken out from the conduit 31 to the outside.

  In addition, it is necessary to deaerate ultrapure water. If dissolved oxygen is present in the ultrapure water that passes through, an oxide film is formed on the silicon wafer mounted in the wafer holder 3 and is used as a specimen. This is because the ion exchange resin may not be correctly inspected. Therefore, ultrapure water from which dissolved oxygen is removed is used as the ultrapure water used in the inspection method of the present invention. Alternatively, as shown in the inspection apparatus of FIG. 1, before the ultrapure water is supplied to the column 2, the ultrapure water is degassed by the deaeration processing means such as the degassing membrane device 1. As the deaeration treatment means, known means can be adopted, and it is preferable to use a small deaeration membrane device. In addition, if the ultrapure water supplied from an ultrapure water manufacturing apparatus is a water quality with a dissolved oxygen concentration of 100 μg / l or less, the deaeration membrane apparatus 1 can be omitted from the configuration of the present invention.

  Next, an ion exchange resin inspection method using the ion exchange resin inspection apparatus shown in FIG. 1 will be described. First, the ion exchange resin previously washed with ultrapure water (UPW) is packed into the column 2 as a specimen. The amount of ion exchange resin packed into the column 2 is 500 ml to 2000 ml.

  In addition, a silicon wafer having a diameter of 6 inches to 12 inches is prepared, and the silicon wafer is subjected to a dilute hydrofluoric acid treatment in a clean environment, and a pretreatment for removing the natural oxide film on the surface is performed. Next, the pre-treated silicon wafer is mounted on the wafer holder 3 in a clean environment. The silicon wafer to be used may be any of n-type, p-type, or bare silicon wafers cut from the silicon single crystal ingot with an inclination angle with respect to the (100) plane of the ingot. However, the tilt angle of the silicon wafer to be cut out is preferably in the range of 3 ° <θ <5 ° in the [011] direction with respect to the (100) plane. For example, in the inspection method of the present invention, if a 4 ° off-type silicon wafer is used, it is possible to evaluate the silicon crystal as a whole, so that a stricter inspection can be performed.

  Next, in the ion exchange resin inspection apparatus configured as described above, ultrapure water is introduced into the degassing membrane device 1 and subjected to deaeration treatment, and then passed through the column 2. When water is passed, the state of the deaeration process is sufficiently confirmed so that no air is trapped in the wafer holder 3. The reason for deaeration of ultrapure water is to prevent the formation of an oxide film on the silicon wafer mounted on the wafer holder 3 as described above. Note that the dissolved oxygen concentration of ultrapure water for passing through the column 2 is DO 100 μg / l or less. Moreover, the water flow rate of ultrapure water shall be 250-2000 ml / min, and water flow time shall be 15 minutes-120 minutes.

  The ultrapure water deaerated by the deaeration membrane device 1 is introduced into the column 2 and then into the wafer holder 3. The ultrapure water introduced into the wafer holder 3 comes into contact with the wafer 5 in the wafer holder 3 and flows out from the conduit 31 to the outside.

  On the other hand, the ultrapure water introduced into the resin column 2 flows out of the resin column 2 after coming into contact with the ion exchange resin 23 as an object, and a part of the outflowed ultrapure water is supplied to the first wafer holder 54. The first wafer 55 is introduced into the first wafer 55 and taken out from the first wafer contact water transfer pipe 57 to the outside.

  After the ultrapure water is brought into contact with the wafer 5 within a predetermined time range of 15 min to 120 min as described above, the wafer 5 is taken out from the wafer holder 3 and used in a clean state at a room temperature to 150 in a clean state. Dry within the range of ° C.

  By the way, the silicon wafer surface is bonded with hydrogen atoms to the silicon atoms of the exposed wafer, so that all of the silicon on the outer surface of the wafer is subjected to hydrogen termination treatment. It is said to be chemically stable. However, when a silicon wafer subjected to hydrogen termination is etched, the degree of bonding between silicon atoms and hydrogen atoms decreases, and hydrogen atoms on the surface of the silicon wafer are partially removed.

  Therefore, as the ion exchange resin method, the average roughness Ra value (nm) and the maximum height difference Rmax value (nm) of the wafer surface roughness are measured, and pass / fail is determined based on the above formulas (1) and (2). Judgment can be made.

  That is, the Ra value and the Rmax value, which are the determination values, are compared with the permissible reference values A and B, respectively, and whether or not the ion exchange resin as the subject is good is determined based on whether or not the determination value is equal to or less than the permissible reference value. You can also

  The allowable reference value A in the above equation (1) varies depending on the purpose of use of the ion exchange resin, but is 0.22 nm or less, preferably 0 in order to ensure the quality corresponding to the rapid performance improvement of recent semiconductor products. It is preferable to set it to 20 nm or less. That is, in the present invention, based on the above formula (1), it is confirmed that the Ra value as a judgment value is 0.22 nm or less, and the ion exchange resin 4 in the column 2 is shipped as a quality acceptable product. It is preferable to use it. The allowable reference value B in (2) is preferably set to 3.0 nm or less, preferably 2.3 nm or less, for the same reason as in the case of formula (1). That is, in the present invention, based on the above formulas (1) and (2), it is confirmed that the Ra value and the Rmax value, which are judgment values, are not more than the permissible reference values A and B, respectively. It is preferable to ship and / or use the exchange resin 4 as a quality acceptable product. The Ra value and Rmax can be measured by using measuring means such as an AMF (Atomic Force Microscope atomic microscope) or a tapping mode atomic force microscope.

  One embodiment of the wafer holder 3 used in the ion exchange resin inspection apparatus of FIG. 1 is shown in FIGS. The wafer holder shown in FIGS. 2A and 2B includes an upper lid 110 and a bottom plate 120 in which a circular recess 121 on the upper surface is closed by the upper lid. The outer shape of the upper lid 110 and the bottom plate 120 is, for example, circular, and a water supply port 111 is formed at the center of the upper lid, and a drain port 122 is opened at the center of the bottom plate 120. Positioning projections 123 are provided on the peripheral portion of the upper surface of the bottom plate 120 at equal intervals in the circumferential direction. Correspondingly, concave portions for receiving the positioning projections are provided on the peripheral portion of the lower surface of the upper lid. Accordingly, when the upper lid is placed on the upper surface of the bottom plate and the concave portion of the upper lid is fitted into the positioning protrusion 123, the upper lid correctly overlaps the bottom plate and closes the upper surface of the circular recess 121 of the bottom plate.

  The inner diameter of the circular recess 121 in the bottom plate is sufficiently larger than the diameter of the wafer W to be held, and the upper end of the drainage port 122 opens at the center of the bottom of the recess. On the bottom surface of the recess 121, a plurality of, in the drawing, three radial ridges 124 are provided at regular intervals in the circumferential direction. The inner end of the radial trough 124 is located around the drainage port 122, and the outer end is spaced apart from the inner peripheral surface of the recess 121 inward. The wafer W is held horizontally on the plurality of radial ridges 124. Therefore, a staircase-shaped support base 125 having a step 126 on which the peripheral edge of the wafer is placed is provided on the outer end of each ridge. The level difference of the level 126 corresponds to the thickness of the wafer (about 0.6 mm). Further, if necessary, a support portion 127 that supports the lower surface in the radial direction of the wafer is provided on the intermediate portion of each of the flanges 124.

  The lower surface of the upper lid 110 is provided with a Mt. Fuji water passage recess 112 connected to the lower end of the water supply port 111. The inner diameter of the water passage recess 112 is equal to the inner diameter of the circular recess 121 in the bottom plate. The reason why the water passage recess 112 is referred to as Mt. Fuji is that, in a cross-sectional shape, the lower surface of the recess 112 is radially outward and gradually approaches the upper surface of the wafer W that is horizontally supported by the stepped support platform 125. It is. The water that has reached the peripheral edge 121 ′ of the bottom of the depression flows through the gap between the bottom of the depression 121 and the lower surface of the wafer lifted by the radial ridge toward the central drain 122, It flows out from the outlet 122.

  The water supply port 111 on the top lid and the drain port 122 on the bottom panel are screwed to shut off the outside air and the inside of the container, and when the container is carried outside the clean room, the valve is closed and contact with water is avoided. Open only when implementing. As a valve provided at the water supply port 111, it is preferable to use a three-way valve (switching between raw water → inside the container and raw water → discharge) 113. Before bringing the container into contact with water, the valve 113 can be switched between “raw water → discharge” so that water can flow without entering the container. There is an effect that it can be washed. The valve 128 provided at the drain port 122 may be a two-way valve for opening and closing.

  As the material of the upper lid 110 and the bottom board 120, a synthetic resin that is relatively easy to process and durable is used. Examples of such a synthetic resin include a polypropylene resin, a fluorine resin, and an acrylic resin. In addition, in order to remove impurities adhering to the surface of the container, cleaning with heated ultrapure water or cleaning using ultrasonic waves is performed before using the container.

  By the way, if air remains in the wafer holder 5 during water flow, an oxide film may be formed on the mounted silicon wafer. Therefore, in order to remove the air inside the wafer holder, it is preferable to provide a two-way valve 114 for releasing air. The air venting two-way valve 114 is provided on the upper side of the upper lid 110 and communicates the water recess 112 with the outside of the wafer holder. Then, the three-way valve 113 is switched from “raw water → inside the container” so that ultrapure water is passed through the wafer holder, the valve 128 is closed, and ultrapure water is introduced into the wafer holder. Air is pushed out through the two-way valve 114.

  In the example of FIG. 2A, the air vent pipe provided with a two-way valve for air vent is provided so as to penetrate the upper lid 110, but is configured to penetrate the bottom plate 120. In this case, the air is removed by turning the wafer holder upside down.

  In addition to the wafer holder 5 described above, a column-type contact container may be used as a container for bringing ultrapure water and a silicon wafer into contact with each other. A predetermined amount of silicon material is packed on a water collecting plate in the column, sample water is supplied from above the packing, and sample water that has been contacted is discharged from below the packing. Moreover, you may use a washing tank type contact container. A wafer holder on which a silicon wafer is placed is placed in a cleaning tank, ultrapure water is introduced from the lower part of the cleaning tank and brought into contact with the silicon wafer in an upward flow, and then sample water is discharged from the upper part of the cleaning tank by overflow. The constituent material may be any material that has very little elution even when it comes into contact with water, and an acrylic resin is preferred.

Further, in this example, ultrapure water that has flowed out to the column 2 can be sent from a pipe 21 to an ion chromatography analyzer (not shown), and impurities of metals, SO ₄ ion concentration, and the like can be measured. The ultrapure water that has contacted the wafer 5 loaded in the wafer holder 5 is also sent to an ion chromatograph (not shown) from the pipe 31 and measured for impurities, SO ₄ ion concentration, etc. Water quality can be evaluated at the same time.

  Moreover, the above-mentioned ion exchange resin can implement the test | inspection method of this invention in any when a cation exchange resin alone, an anion exchange resin alone, or a cation exchange resin and an anion exchange resin are mixed. In addition, the inspection method of the present invention can be carried out on either an ion exchange resin that has been regenerated and washed at a regenerative washing plant or a new ion exchange resin.

Although the method for inspecting the ion exchange resin packed in the column 2 has been described above, an apparatus loaded with an ultrafiltration membrane can be arranged in place of the column 2 to similarly inspect the ultrafiltration membrane.

  EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples.

(Conventional inspection method)
The washed cation exchange resin and anion exchange resin were mixed at an exchange capacity ratio of 1: 1 to prepare a mixed ion exchange resin (hereinafter referred to as “mixed resin A”). A part of the mixed resin A was packed in a resin column of an ion exchange resin inspection apparatus. Next, ultrapure water was passed through the resin column, and the quality of the ultrapure water flowing out of the resin column was measured. As a result of measuring the quality of the ultrapure water in contact with the mixed resin A, the TOC was 1 ppb or less, and the specific resistivity was 18.2 MΩ · cm.

  Next, all of the mixed resin filled in the non-regenerative ion exchange column provided in the subsystem of the ultrapure water production apparatus was removed, and the mixed resin A was newly filled in the ion exchange column. In this way, ultrapure water was produced using a non-regenerative ion exchange tower exchanged with the mixed resin A, and the silicon wafer was washed using the obtained ultrapure water.

  As a result, after replacement of the mixed resin, the normal resin wafer could be produced, but after the mixed resin filled in the non-regenerative ion exchange tower was replaced with the mixed resin A as described above, On the first day after the replacement, there was a problem that the oxide film of the cleaned silicon wafer had a breakdown voltage failure.

[Example 1]
(Inspection method of the present invention)
A 6-inch diameter n-type silicon wafer was cleaned with dilute hydrofluoric acid using a Teflon (registered trademark) bath to clean the surface of the wafer. The cleaned n-type silicon wafer was mounted on a wafer holder 5 having a structure shown in FIG. Next, the wafer holder 5 was mounted on the apparatus shown in FIG. 1 to constitute an ion exchange resin inspection apparatus.

  On the other hand, the mixed resin A was used as the primary acceptable product, and the cleaning of the mixed resin A was further continued. Then, the inspection using the inspection apparatus of FIG. 1 is performed, and the mixed resin A is washed until the determination values represented by the above formulas (1) and (2) are lower than the allowable reference values A and B, respectively. A mixed resin was prepared. The inspection items and the inspection results of the acceptable mixed resin are as shown in Table 1.

次に、超純水製造装置のサブシステムに設けられた非再生型のイオン交換塔に充填されていた混合樹脂を全て除去し、上記の合格混合樹脂を該イオン交換塔に新たに充填した。このように、合格混合樹脂に交換した非再生型のイオン交換塔を使用して超純水を製造し、得られた超純水を使用してシリコンウエハを洗浄した。

Next, all the mixed resin filled in the non-regenerative ion exchange tower provided in the subsystem of the ultrapure water production apparatus was removed, and the above-mentioned acceptable mixed resin was newly filled in the ion exchange tower. In this way, ultrapure water was produced using a non-regenerative ion exchange tower exchanged with an acceptable mixed resin, and the silicon wafer was washed using the obtained ultrapure water.

  As a result, as described above, after replacing the mixed resin filled in the non-regenerative ion exchange tower with an acceptable mixed resin, the non-defective product rate is 90% or more during the operation period of 3 months from the first day after the replacement. Thus, there was no problem that the oxide film of the cleaned silicon wafer had a breakdown voltage failure.

  As described above, according to the inspection method of the present invention, the quality of the product can be inspected immediately before shipment in the resin washing factory. It was confirmed that even when the ion-exchange resin was replaced and the manufacture of the semiconductor product was started after the lapse of one day, it was difficult for quality defects to occur.

[Example 2]
In Example 1, instead of the column 2 filled with the mixed resin A, which is the analyte in FIG. 1, the ultrafiltration membrane module (UF membrane, KU-1510HS, manufactured by Kurita Kogyo Co., Ltd., hollow fiber polysulfone) In the same manner as in Example 1, the permissible reference values A and B are measured, and ultrapure water is used until the reference molecular weight falls below both reference values. Washing was performed to obtain an acceptable product of the ultrafiltration membrane module. Next, this passed product is replaced with a membrane module of an ultrafiltration membrane device provided in the subsystem of the ultrapure water production device, ultrapure water is produced, and the obtained ultrapure water is used to produce a silicon wafer. As in Example 1, normal operation was possible from the first day after replacement.

  (Go to paragraph 38)

It is one embodiment of the structure outline | summary of the inspection apparatus of the ion exchange resin comprised in order to implement the inspection method of this invention.

(A) It is sectional drawing of one Embodiment of the silicon contact container which comprises the test | inspection apparatus used in the test | inspection apparatus of the ion exchange resin shown in FIG. (B) It is a perspective view of the bottom board 120 of the silicon contact container of FIG. 2 (A).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Deaeration membrane apparatus 2 Column 3 Wafer holder 4 Ion exchange resin as a test object 5 Wafer 11, 12, 21, 31 Pipe line 110 Upper lid 111 Water supply port of an upper lid 112 Water-conducting recessed part of an upper lid 114 Two-way valve for venting air 120 Bottom plate 121 Circular recess in the bottom plate 122 Drain outlet of the bottom plate 124 Radial ridges on the bottom plate 125 Stair-shaped support base of the radial ridges W Wafer

Claims (6)

In the inspection method of ion exchange resin or ultrafiltration membrane used in the ultrapure water subsystem for semiconductor manufacturing,
Column effluent discharged from the column by supplying ultrapure water from which dissolved oxygen has been removed to a column packed with an ion exchange resin as an analyte or an ultrafiltration membrane loaded as an analyte. The ion exchange resin or ultrafiltration membrane is characterized by determining the quality of the ion exchange resin or ultrafiltration membrane as the analyte by measuring the surface state of the wafer after contact with the wafer. Filtration membrane inspection method. The measurement of the surface state of the wafer is performed by means for measuring the average roughness Ra value (nm) and the maximum height difference Rmax (nm) of the wafer surface roughness,
Formula (1): Ra value ≦ allowable reference value A
And the following equation (2): Rmax value ≦ allowable reference value B
The Ra value and the Rmax value, which are the determination values, are compared with the allowable reference values set in advance with non-defective products based on the determination formula shown by, and whether or not the determination values are equal to or less than the allowable reference values A and B, respectively. The method of testing an ion exchange resin or ultrafiltration membrane according to claim 1, wherein the quality of the ion exchange resin or ultrafiltration membrane as an analyte is determined. As the above-mentioned wafer, any one of a bare silicon wafer cut out from an n-type, p-type, and silicon single crystal ingot with an inclination angle with respect to the (100) plane of the ingot is used. The inspection method of the ion exchange resin or ultrafiltration membrane of Claim 1 or 2. The ultrapure water having a dissolved oxygen concentration of 100 µg / l or less is used as ultrapure water that is passed through a column packed with the above ion exchange resin or an apparatus loaded with an ultrafiltration membrane. The inspection method of the ion exchange resin or ultrafiltration membrane in any one of 1-3. The method for inspecting an ion exchange resin or ultrafiltration membrane according to any one of claims 1 to 4, wherein the column effluent is brought into contact with a wafer filled in a wafer holder. The ion exchange resin or ultrafiltration membrane according to any one of claims 1 to 4, wherein the column effluent is brought into contact with a wafer placed on a wafer holder in a wafer cleaning tank. Inspection method.

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