JP2003224182A - Abnormality detecting device for substrate carrying container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an abnormality detecting device for a substrate carrying container which can detect a gaseous contaminant being abnormally present in the atmosphere in the substrate carrying container in such a case. <P>SOLUTION: Provided are the container which carries a substrate and a sensor which detects the gaseous contaminant present in the container. The sensor is equipped with PH paper which discolors with the gaseous contaminant and an optical sensor which detects its discoloration. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate transfer container suitable for storing or transferring a substrate such as a semiconductor wafer or a liquid crystal substrate in an atmosphere of high cleanliness, and more particularly to a gaseous pollutant inside the container. System for detecting abnormalities in

[0002]

2. Description of the Related Art When a semiconductor wafer, a glass substrate for a liquid crystal device, or the like is stored or transported, when fine particles such as dust or gaseous pollutants adhere to the substrate, the substrate is contaminated and the manufacturing yield of the device is increased. Leading to a decrease in Therefore, to store and transport semiconductor wafers, glass substrates, and other substrates that require high cleanliness, create a clean space free from contaminants such as fine particles and gaseous contaminants, and place the substrate in that space. It is necessary to store, store and transport.

As means for creating such a locally clean space, a particle removal filter such as a HEPA or ULPA filter and a chemical filter for removal of gaseous pollutants are used in a container, and air is circulated by a fan through these. There is known a substrate transfer container that stores a substrate in clean air that has passed through a filter.

[0004]

In a substrate transfer container provided with such a chemical filter for removing gaseous pollutants, when a gaseous pollutant is present in the container, it is removed by the above-mentioned filter. The container generally has a small volume. Therefore, when the substrate brought into the container contains an extremely large amount of gaseous pollutants in the previous step, the gaseous pollutants may adhere to the inner wall of the container and contaminate the container itself. Therefore, when the gaseous pollutant is abnormally present inside the container, it is necessary to detect it and take immediate action.

The present invention has been made in view of the above-mentioned circumstances, and when an abnormal gas pollutant is present in the atmosphere in the substrate transfer container, it can be detected. An object of the present invention is to provide a substrate transfer container including

[0006]

The substrate transport container of the present invention is a container for storing or transporting substrates, which comprises a sensor connected to the container for detecting a gaseous pollutant present in the container. Is characterized by.

According to the present invention, since the sensor for detecting the presence of the gaseous pollutant in the substrate transfer container is provided, it is possible to immediately detect the abnormality in the substrate transfer container. As a result, it is possible to prevent the substrate transport container itself from being contaminated, and it is possible to quickly detect an abnormality or the like in the previous process.

Here, it is preferable that the sensor includes PH paper that changes color with respect to the gaseous pollutants, and an optical sensor that detects the color change. However, as a method for detecting a gaseous pollutant, any means may be used as long as it is a quick and easy maintenance method. For example, a sensor using an electrochemical method or an electric method can be used.

Further, it is preferable that a timer mechanism for adjusting the time for starting the operation of the sensor is provided. As a result, it is possible to detect the gaseous pollutant in a state where the substrate to be detected has been calmed down for a predetermined time after being input.

[0010]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an abnormality detecting device for a substrate carrying container according to an embodiment of the present invention. The substrate transport container 11 is a container for housing a substrate 12 such as a semiconductor wafer and storing or transporting the substrate 12. A fan 13, a chemical filter 14 that adsorbs and removes gaseous pollutants, and a particle removal filter 15 that removes particles are provided in the substrate transfer container 11.
It has and. A circulating airflow is formed so that the fan 13 causes the airflow to flow through the chemical filter 14 and the particle removal filter 15, and the cleaned airflow to flow into the housing portion of the substrate 12.

Here, the chemical filter (gas pollutant removal filter) 14 will be described. Various means for removing the gaseous impurities can be selected according to the substance to be removed. As a basic gas removing means, strong acid,
Weakly acidic cation non-woven fabric or fiber, strongly acidic or weakly acidic cation exchange beads and the like are suitable, and these can efficiently remove the basic gas. Also, basic gas can be removed by activated carbon or ceramics impregnated with an acidic chemical solution. As a means for removing acidic gas, boron, phosphorus, etc., strong basic, weak basic anion exchange nonwoven fabric or fiber, or strong basic, weak basic cation exchange beads are suitable, and acidic gas etc. can be efficiently used. Can be removed. Further, the activated carbon or ceramic impregnated with the basic chemical liquid can also remove the acidic gas and the like.

Organic matter can be removed by activated carbon, activated carbon fiber, zeolite, molecular sheep, silica gel, porous ceramics. Ozone can be removed by media such as granular or sheet-shaped manganese dioxide supported or attached or activated carbon. In addition, vaporized metal ionized,
For example, copper sulfate or the like can be removed with an ion exchange non-woven fabric or ion exchange beads. The structure of the adsorbing material can be appropriately selected according to the removal target substance and the allowable size, shape, pressure loss, etc. of the filter.

The substrate transfer container 11 is provided with an abnormality detection device 21 for detecting an abnormality of the gaseous pollutants inside the substrate transfer container 11. In the container 11, the air inside the container is piped 22
The sensor container 28 is provided with a branch passage for detecting an abnormality of the gaseous pollutant and for circulating an air flow through the pipe 25 to the container 11. That is, the pipe 2
The airflow is introduced into the sensor chamber 28 through the pipes 2 and 23, and the airflow after the detection of abnormality is completed through the pipes 24 and 25.
It is returned to the downstream side of the No. 1 chemical filter 14. Piping 2
An opening / closing valve 26 is arranged between the pipes 2 and 23, and the pipe 2
An opening / closing valve 27 is similarly arranged between the No. 4 and No. 25. Therefore, by opening / closing the opening / closing valves 26 and 27, it is controlled whether or not the airflow flows through the branch passage.

The sensor container 28 is provided with PH paper 29 that changes color when a gaseous pollutant is present, and the optical sensor 30 detects the color change condition. That is, when unexpected acid and alkali are present in the air flow,
The paper 29 discolors, and this discoloration is detected by an optical sensor 30 such as a CCD image sensor.

The open / close valves 26 and 27 are controlled by a timer 31, and are a control device 3 including a microcomputer or the like.
The opening / closing control for a predetermined time is performed according to the command of 2. The control device 32 also transmits and receives signals to and from the substrate transport container 11.
Thus, opening / closing of the opening / closing valves 26 and 27 can be controlled in synchronization with loading of the substrate 12 into the substrate transport container 11. The substrate transfer container 11 is provided with openings for inserting branch pipes on the upstream side and the downstream side of the chemical filter 14 in the circulating air flow path, and the pipes 22 and 25 are inserted into the openings, except when the branch paths are connected. The opening may be sealed with a rubber stopper or the like. Further, the substrate container 11 itself may be provided with a set of the abnormality detecting device 21 including the pipes 22 and 25, the opening / closing valves 26 and 27, the sensor container 28, the optical sensor 30, and the like.

FIG. 2 is a diagram showing an example of changes in PH in the substrate transfer container. In the case of this example, the case is shown in which the PH in the air flow in the substrate transport container is very high at the time of loading the substrate and then gradually decreases with the passage of time. In such a case, the opening / closing valves 26, 27 by the timer 31
It is preferable that the opening / closing timing of (1) is taken into the sensor container 28 side by the air flow in the container 11 after a certain period of time has elapsed since the substrate was charged. This makes it possible to detect the presence / absence of the abnormality after the PH in the air flow in the substrate transport container has settled in a steady state. The operation of the timer 31 may be changed in advance for each process for the target container and the target process.

A plurality of gas species are mixed in the air to be measured. Therefore, when measuring the gas concentration with a combination of a color-developer impregnated paper that changes the color of each target gas with respect to gaseous pollutants and an optical sensor that detects the color change, the color-developer impregnated paper is used to prevent interference of multiple gas species. Is preferably set to measure only a single gas. As the above-mentioned color-forming agent-impregnated paper, papers that are roughly divided into three types and are used in practice. Firstly, the metal salt impregnated in the paper is reduced to a measuring gas to generate a color, for example, phosphine,
There are arsine, etc. Secondly, it is assumed that the compound impregnated in the paper and the measuring gas react with each other to generate a color,
For example chlorine. Thirdly, there is, for example, ammonia or the like as a material capable of measuring only a specific gas by impregnating a paper with a PH indicator which discolors in a narrow region.

The abnormality detecting device for a substrate transport container according to the present invention is not limited to the above-described illustrated example, and various modifications can be made without departing from the scope of the present invention. .

[0020]

As described above, according to the present invention, it is possible to detect an abnormality regarding a gaseous pollutant in a substrate transfer container, which reduces the manufacturing yield of stored items such as semiconductor substrates. It is possible to prevent such abnormalities.

[Brief description of drawings]

FIG. 1 is a diagram showing a substrate transfer container according to an embodiment of the present invention and an abnormality detection device therefor.

FIG. 2 is a graph showing an example of changes in PH in a substrate transport container.

[Explanation of symbols]

11 Substrate transport container 12 Substrate (semiconductor wafer) 13 fans 14 Chemical filter 15 Particle removal filter 21 Abnormality detection device 22, 23, 24, 25 Piping 26,27 open / close valve 28 sensor containers 29 PH paper 30 Optical sensor 31 timer 32 control device

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 21/02 B65D 85/38 R (72) Inventor Ryo Tanaka 11-1 Haneda Asahi-cho, Ota-ku, Tokyo In the EBARA CORPORATION (72) Inventor Yoko Yoko 11-11 Haneda Asahi-cho, Ota-ku, Tokyo F-term inside the EBARA Corporation (reference) 2G042 AA01 CB01 DA08 FB07 FC00 GA05 2G054 AA01 CA03 CE01 GB10 3E096 BA15 CA02 DA26 DC02 FA03 FA22 FA40 GA20 5F031 CA02 CA05 EA14 EA19 JA02 JA08 JA22 JA31 NA14 NA15 NA20

Claims (4)

[Claims] 1. An abnormality detecting apparatus for a substrate transfer container, comprising: a container for storing or transferring a substrate; and a sensor connected to the container for detecting a gaseous contaminant existing in the container. . 2. The abnormality detecting device for a substrate transfer container according to claim 1, wherein the container is provided with a chemical filter for removing gaseous pollutants and a fan. 3. The abnormality detecting device for a substrate transport container according to claim 1, wherein the sensor comprises PH paper that changes color with respect to the gaseous pollutants, and an optical sensor that detects the color change. . 4. The abnormality detecting device for a substrate transport container according to claim 1, further comprising a timer mechanism for adjusting a time for starting the operation of the sensor.