JPH07272992A - Clean space system - Google Patents

Abstract

PURPOSE:To provide a space cleaning system in which the state of a space to be cleaned can be monitored at all times to keep it in an appropriate state, the safety of its atmosphere against human body be secured, its maintenance be automated, and the contamination against specific molecules be reduced even in an atmosphere using air. CONSTITUTION:The title system is equipped with detecting means 6 and 7 for detecting in a space such a substance that is harmful or useful for a processing substrate in the space among gases constituting the space to be cleaned, or a liquid or solid substance containing therein, a control means 10 for optimizing the detection quantity according to the detected quantity, and a means 13 for removing the harmful substances from the space or adding useful substances.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clean space system, and particularly to the semiconductor industry, the liquid crystal industry, which requires a clean environment,
It can be used in industries such as biotechnology and medicine.

[0002]

2. Description of the Related Art In the semiconductor industry, liquid crystal industry, biopharmaceutical industry, etc., clean booths, clean rooms,
Production activities are carried out using a highly clean environment such as a clean box and a clean tunnel. FIG. 5 illustrates the structure of a clean booth as an example of means for realizing these high cleanliness environments. In the clean booth, a sheet 5 is placed around the clean booth so as to be substantially isolated from the atmosphere, and processing such as transferring or storing the processing substrate 4 such as a semiconductor wafer to the next step is performed. Then, a (particle) filter 3 such as a HEPA filter is attached to filter the atmosphere, and the fan 2 is rotated by the prime mover 1 to send the cleaned atmosphere in which particles are removed into the clean booth. ing.

A clean booth having such a structure is provided with a filter 3
Since it filters particles in the air, it is quite effective in removing pollutant particles, but is completely useless for molecular-level pollution such as adhesion of natural oxide film. Therefore, it is conceivable to fill the space to be cleaned with an inert gas such as clean nitrogen gas in order to eliminate molecular contamination such as adhesion of a natural oxide film on the processing substrate 4. However, for example, when the processing substrate is stored in a closed structure such as a storage of semiconductor wafers, the open structure such as the clean booth shown in FIG. 5 is filled with an inert gas and diffuses to the outside. By doing so, it is clear that the worker has a safety problem of lack of oxygen. Therefore, it is considered effective to fill the space to be cleaned in the clean booth with an inert gas from the viewpoint of preventing the treated substrate from being contaminated with molecules. It cannot be adopted.

Further, in the clean booth shown in FIG. 5, in regard to conventional maintenance, a particle counter is arranged in the space to be cleaned, the cleanliness is detected, and the filter 3 is used.
Find the performance deterioration due to clogging of the filter, and then replace the filter. Alternatively, after a certain period of time, measures such as uniformly replacing the filter were taken. Therefore, for example, the performance of the filter cannot be found unless the particle counter is used for measurement, and it is far from maintaining the clean space optimally.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the prior arts described above, and it is necessary to constantly monitor the state of the space to be cleaned and maintain it in an optimum state. An object of the present invention is to provide a clean space system capable of ensuring safety of a space atmosphere against a human body, automating maintenance, and reducing pollution of specific molecules even in an atmosphere using air.

[0006]

SUMMARY OF THE INVENTION The clean space system of the present invention is a gas that constitutes the space to be cleaned, or a liquid or solid substance contained in the gas, which is harmful or beneficial to the treatment substrate in the space. And a control means for optimizing the detection amount according to the detection amount, and a means for removing a harmful substance or adding a beneficial substance from the space. Characterize.

[0007]

Since the detecting means, the control means and the substance removing and adding means are provided, the space to be cleaned can be controlled to a desired clean state. Therefore, even if the condition of the space to be cleaned changes, or the required cleaning condition for the processing substrate changes, it is possible to flexibly cope with it. Further, since the sensor can detect information on cleanliness and automatically control various parameters relating to cleanliness, maintenance can be automatically performed. Further, even if the space to be cleaned is a gas having a low oxygen concentration, it is possible to automatically ensure the safety of the worker.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a clean space system according to a first embodiment of the present invention. 2 shows a clean space system according to a second embodiment of the present invention, and FIG. 3 is a top view of the clean booth shown in FIG. FIG. 4 shows a clean space system according to a third embodiment of the present invention. In the drawings, the same reference numerals indicate the same or corresponding parts.

In FIG. 1, the space to be cleaned is the space surrounded by the sheet 5. In the clean booth, for example, a processing substrate 4 requiring a high degree of cleanliness such as a semiconductor wafer is handled by a robot that is transferred to the next process, or is stored in a transfer box for transfer to the next process. To be done. The prime mover 1 is for rotating the fan 2 which sends out the gas forming the space to be cleaned into the space to be cleaned surrounded by the sheet 5 at a free rotation speed. The filter 3 is for removing harmful substances from the gas forming the space to be cleaned. The filter 3 is a HEPA filter or ULPA filter that removes particles, or an ion exchange resin such as a chemical filter that adsorbs foreign molecules by a chemical reaction. The sensor 6 detects various parameters of the space to be cleaned, and is, for example, a dust counter or a sensor for detecting chemical foreign molecules. The output of the sensor 6 is sent to the sensor information processing device 7, and a signal from the sensor 6 is compared with a reference value to issue a control instruction to various control means provided in advance. The prime mover control processing unit 8 controls the rotation speed and the like of the prime mover 1 according to an instruction from the sensor information processing device 7, and controls the air flow rate and the like of the gas sent into the space to be cleaned.

The second embodiment of the present invention shown in FIGS. 2 and 3 is a filter moving system in which the clean space system shown in FIG. 1 is further provided with another filter 9 and the filters 3 and 9 are movable. The mechanism 11 is provided. The filter moving mechanism control processing unit 10 determines an appropriate moving amount of the filter 3 or the filter 9 according to an instruction from the sensor information processing device 7, and instructs the filter moving mechanism 11 to filter 3,9.
To move. In this embodiment, the filter moving mechanism section 11 is composed of a slide mechanism using a linear motor.

The third embodiment of the present invention shown in FIG. 4 is such that the additive can be further supplied to the clean space system of the second embodiment shown in FIGS. 2 and 3. The additive source 13 includes an additive source 13 that removes harmful substances in the clean space or adds beneficial substances to the processing substrate 4 in the clean space. The additive processing unit 12 controls the sensor information processing device 7 to supply an appropriate amount of the additive substance from the additive supply source into the space to be cleaned.

Next, the operation of the clean space system of the present invention will be described. The space to be cleaned is filled with the atmosphere forming the space or an inert gas such as N ₂ gas. Gas molecules, liquid fine particles, solid fine particles, and the like are present in the gas that constitutes this clean space. Among these substances, some are harmful and some are beneficial to the processing substrate such as a semiconductor wafer.

For example, it is harmful to a semiconductor wafer that an alkali metal (N
a, K), heavy metal (F
e, Pu, Ni, Zn), P-type layer inversion failure
There are group III elements (B, Al), group V elements (P, As, Sb) that cause N-type layer inversion defects, and the like. In addition, radioactive elements (U, Th) that cause soft error defects, anions (CO ₃ , NO ₂ , SO ₄ , Cl, NH ₄ ) that cause etching rate abnormalities, foreign matter generation, corrosion, etc., watermarks, and poor conductivity. An organic compound (polymer compound) that causes is harmful. In addition, various fine particles of L
This affects defects such as the SI wiring pattern and reduces the manufacturing yield.

Substances that are beneficially present in a clean space on a processing substrate such as a semiconductor wafer include ions generated by an ion generator, oxygen molecules in a gas having an oxygen concentration of 18% or less, and electron showers. The ions in the clean space are useful for neutralizing static electricity on semiconductor wafers and handling jigs. Further, supplying oxygen into the cleaning space is useful for preventing oxygen deficiency. Further, the electron shower can be used for removing the charge of fine particles. The sensor 6 of the present embodiment senses the amount, intensity, height, density, etc. of the presence of these harmful substances or beneficial substances according to the requirement. Table 1 shows a typical sensing means.

[0015]

[Table 1]

If the detection sensitivity of the sensor 6 is insufficient or lacks in reliability, it may be reinforced by using a dedicated microanalyzer corresponding to various components. The signal from the sensor 6 is analyzed by the sensor information processing device 7, and when it is deviated from an appropriate value, a predetermined adjusting means is controlled. For the control of the adjusting means, the motor control processing unit 8 may control the gas flow rate from the fan 2, and the filter moving mechanism control processing unit 10 may control the filter moving mechanism 1.
The filter 3 and the filter 9 may be moved via 1 to control them. In addition, the additive supply source 1 by the addition amount processing unit 12
You may make it supply the additive from 3 into the space which should be cleaned.

Table 2 shows various means of removing harmful substances or adding beneficial substances.

[0018]

[Table 2]

In Table 2, the filter means is a HEPA filter or U for merely removing fine particles.
The concept includes not only the LPA filter but also an ion chemical adsorption filter that adsorbs and removes molecules such as ammonia. Explaining with an example of a filter, as in the second embodiment shown in FIGS. 2 and 3, when the filter 3 and the filter 9 are prepared as movable structures, for example, it is necessary to adsorb and remove molecules such as ammonia. Can be selectively used according to each situation by inserting an ion-exchange chemisorption filter and inserting a ULPA filter when simple particle removal is required.

It is also possible to use the filters 3 and 9 as the same type of filter, and replace the filters according to the filter contamination limit information and use them alternately. Filter 3,9
When the number of stages is increased, the flow path loss increases, the load on the fan increases, and the period of use of the filter also shortens. Therefore, by replacing and using the same type of filter, it is possible to reduce the load on the prime mover and appropriately control the particle concentration. Further, when the particle contamination is increasing in the sensor information, it is possible to reduce the particle contamination by replacing the idle filter, cleaning the filter by washing or the like, and reusing it. Furthermore, it is also possible to detect the airflow velocity in the space to be cleaned, the gas circulation amount, and increase or decrease the rotation speed of the fan 2 to optimize and control the airflow velocity, the gas circulation amount, or the like. In this way, the control content can be selected according to the application.

Similarly, the addition of the beneficial substance can be carried out as follows. For example, by detecting the oxygen concentration by the sensor 6 and supplying oxygen from the additive supply source 13, the oxygen concentration required in the space to be cleaned can be maintained. Similarly, ions can be supplied from the additive supply source 13 into the space to be cleaned, and an electron shower can be applied to the processing substrate 4. If a process such as sealing a processing substrate such as a semiconductor wafer in a container for transfer is performed in a space cleaned by using such means, the conventional pollution will be caused especially when the space to be cleaned is the atmosphere. It is possible to significantly reduce the increase in pollution when transferring a wafer in the atmosphere, which has been troublesome.

In this embodiment, a clean booth is described as an example, but a clean box, a clean room,
Of course, the same can be applied to a clean tunnel or the like. Various modifications can be made without departing from the above-described embodiments without departing from the spirit of the present invention.

[0023]

According to the present invention, it is possible to create an arbitrary purified atmosphere by positively controlling the environment in the clean space. As a result, the most effective and efficient production activities can be carried out in the fields that require a highly clean environment.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a cleaning space system according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a cleaning space system according to a second embodiment of the present invention.

3 is a top view of the cleaning space system of the embodiment shown in FIG.

FIG. 4 is an explanatory diagram of a cleaning space system according to a third embodiment of the present invention.

FIG. 5 is an explanatory diagram of a conventional cleaning space system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motor 2 Fan 3,9 Filter 4 Processing substrate 5 Sheet partitioning cleaning space 6 Sensor 7 Sensor information processing device 8 Motor control processing unit 10 Filter moving mechanism control processing unit 11 Filter moving mechanism unit 12 Addition amount processing unit 13 Additive supply source

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location B08B 15/02 F24F 7/00 A G02F 1/13 101 (72) Inventor Fumio Kondo Fujisawa City, Kanagawa Prefecture 4-2-1 Motofujisawa Ebara Research Institute Co., Ltd.

Claims (7)

[Claims] 1. A means for detecting, in the space, a substance that is harmful or beneficial to a treatment substrate in the space, among gases constituting the space to be cleaned, or liquid or solid substances contained in the gas. A clean space system comprising: a control unit that optimizes the detected amount according to the detected amount; and a unit that removes a harmful substance from the space or adds a beneficial substance. 2. The clean space system according to claim 1, further comprising means for transferring or accommodating a substrate which has undergone a treatment process under atmospheric pressure in a space to be cleaned for a next step. 3. A means for detecting a substance that is harmful or beneficial to a processing substrate in the space, among the gas that constitutes the space to be cleaned, or the liquid or solid substance contained in the gas, and the detection information. A means for removing a substance that is harmful to the substrate to be treated or adds a beneficial substance in the gas, which constitutes the space to be cleaned, or a liquid or a solid substance contained in the gas,
Alternatively, the clean space system according to claim 1 or 2, further comprising means for exchanging or regenerating. 4. A means for detecting particle contamination of a gas forming a space in a space to be cleaned, a means for enabling or exchanging or regenerating the contamination removing means according to the contamination information, and the contamination information. 4. The clean space system according to claim 1, further comprising: means for controlling and optimizing an air flow velocity and a circulation amount of a gas forming a space in the space to be cleaned. 5. The clean space system according to claim 1, wherein the processing substrate is a semiconductor wafer or a liquid crystal substrate. 6. The clean space system according to claim 1, wherein the gas forming the space to be cleaned is air. 7. The clean space system according to claim 1, wherein the gas forming the space to be cleaned is nitrogen or another inert gas.