JP2000343049A - Washing device and washing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the cleaning degree of material having a specified linear expansion coefficient or above by adjusting the temperature of a washing medium and the temperature of the atmosphere in a washing chamber based on a signal of each temperature sensor and connecting an ultraviolet light washing chamber to the washing chamber thereby arranging them. SOLUTION: The temperature of the atmosphere in first - fifth washing chambers 23, 33, 34, 37, 39 and in slow cooling chambers 41, 42, 43, the temperature of liquid jetted from water jet devices of transfer paths 27, 56, 57, 58, and the temperature of the washing medium in first - fifth washing tanks 24, 35, 36, 38, 40 are subjected to feedback control by a temperature controller 30 so that the temperature measured by temperature sensors 29a-29i becomes the set temperature. An ultraviolet light washing chamber 48 is connected to the fifth washing chamber 39 of the final process to arrange them, and in the washing chamber 48, material to be washed 20f is subjected to ultraviolet washing by an ultraviolet lamp 49.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning apparatus suitable for cleaning optical materials which can be used in the ultraviolet region and which have a high linear expansion coefficient and a low breaking strength, for example, fluoride crystals, fluoride glass, etc. And a cleaning method.

[0002]

2. Description of the Related Art A cleaning method is a wet cleaning method using a liquid,
It can be classified as a dry cleaning method that does not use any liquid. A typical example of wet cleaning is cleaning of optical components. The optical component is washed after the polishing step, and the target dirt is used for fixing the optical component at the time of polishing, and mainly includes asphalt pitch and beeswax.

FIG. 3 is a block diagram showing a conventional optical component cleaning apparatus. In the conventional cleaning device 1 for optical parts,
First, the target dirt is washed off with one of freon, trichloroethane, and trichlorene in the first cleaning tank 2. In recent years, due to environmental pollution, chemicals that have similar chemical properties and do not pollute the environment are being used instead of these chemicals. In the first cleaning tank, such a chemical (hereinafter, referred to as an alternative solution) may be used. The second washing tank 3 is washed with an alkaline washing solution or a neutral washing solution, the third washing tank 4 is rinsed with city water, the fourth washing tank 5 is rinsed with pure water, and the fifth washing tank 6 is replaced with isopropyl alcohol (IPA). After that, the sixth cleaning tank 7 is finished by IPA vapor cleaning (IPA vapor cleaning). The second cleaning tank 3 and the third cleaning tank 4 are equipped with an ultrasonic generator 8 and a liquid temperature control device 9 to perform ultrasonic cleaning in the cleaning tank or to heat the liquid in the cleaning tank. Is also good.

However, unlike materials for general optical parts, materials having a high coefficient of linear expansion, particularly optical materials usable in the ultraviolet region, change physical properties or break due to temperature changes. Therefore, the cleaning of the optical components made of such a material is performed by hand wiping shown in FIG. 4 without using the cleaning device 1. An organic solvent such as alcohol is applied to an appropriate wiping cloth 10 and pressed with a fingertip 11. The object to be cleaned 12b is placed on a rotatable table 13 which can be arbitrarily rotated, and is wiped by hand from the center toward the outer periphery. Since the work is performed by hand as described above, cleaning of a material having a high coefficient of linear expansion requires skill of a skilled worker. Therefore, the degree of cleanliness of the surface varies greatly depending on the skill of the worker, the degree of contamination of the object to be cleaned, and the like, and is very unstable. Furthermore, it is difficult to completely remove dirt by this cleaning method.

As an example of a wafer cleaning technique used in the semiconductor device manufacturing industry, see Japanese Patent Application Laid-Open No. 6-612.
FIG. 5 shows a configuration diagram of a conventional wet processing apparatus described in Japanese Patent Application Publication No. 14-142. First, a heating chamber 16 for heating to the same temperature as the temperature of the chemical solution 15 is provided. The heating chamber 16 has a hot air inlet 18 and an exhaust port 19, and is adjusted to an arbitrary temperature from the hot air inlet 18. N ₂ is introduced. Wafer 1
Before immersing the carrier 4 and the carrier 17 in the chemical solution 15, the wafer 1
The wafer 4 and the carrier 17 are placed in the heating chamber 16, and the wafer 14 and the carrier 17 are heated to the same temperature as the temperature of the chemical solution 15 in the heating chamber 16, and then immersed in the chemical solution 15. Thereby, the chemical solution 1
Since the temperature of No. 5 does not fluctuate, uniform processing of the wafer 14 can be always performed without wasting time for making the temperature constant.

[0006]

However, in the conventional cleaning apparatus 1 shown in FIG. 3, the difference between the temperature of the liquid (cleaning liquid) in the cleaning tank and the temperature of the atmosphere in the cleaning chamber is large, and the cleaning target 12a
In the case where a material having a high linear expansion coefficient and a low breaking strength among optical materials usable in the ultraviolet region is used, particularly, a material having a linear expansion coefficient of 15 × 10 ⁻⁶ or more is used,
a may be destroyed. In particular, I of the sixth cleaning tank 7
The temperature difference from the PA vapor cleaning is very large and the material is most likely to be destroyed.

Further, the material is not destroyed by the manual wiping shown in FIG. 4, but it is impossible to completely remove the dirt on the surface. When the wet processing apparatus shown in FIG. 5 is used as a cleaning apparatus, the material is not destroyed due to a temperature difference, but is used because there is only one cleaning tank containing a chemical solution (cleaning liquid). Since the cleaning liquid is limited, it is not possible to completely remove surface dirt.

The present invention provides a cleaning apparatus for improving the cleanliness of a material having a high linear expansion coefficient and a low breaking strength, particularly a material having a linear expansion coefficient of 15 × 10 ^-6 or more among optical materials usable in the ultraviolet region. It is intended to provide a cleaning method.

[0009]

In order to solve the above problems, a cleaning apparatus according to the present invention comprises a plurality of cleaning tanks having a cleaning medium for cleaning an object to be cleaned, and a cleaning chamber in which the cleaning tanks are installed. A temperature sensor for measuring a temperature of a cleaning medium in a predetermined cleaning tank and a temperature of an atmosphere in the cleaning chamber in the cleaning tank; and a temperature of the cleaning medium and the cleaning based on signals from the temperature sensors. Temperature adjusting means for adjusting the temperature of the atmosphere in the room, and ultraviolet rays connected to a cleaning chamber related to the cleaning tank used in the final cleaning step so as to be adjacent to the cleaning tank used in the final cleaning step in the cleaning tank. A light cleaning chamber (claim 1).

According to the cleaning apparatus, the temperature of the cleaning medium in the predetermined cleaning tank in the cleaning tank and the temperature of the atmosphere in the cleaning chamber are measured by the temperature sensor and adjusted by the temperature adjusting means. Therefore, by controlling and reducing the difference between the temperature of the cleaning medium in the cleaning tank and the temperature of the atmosphere in the cleaning chamber, the linear expansion coefficient of the optical material that can be used in the ultraviolet region during the cleaning process is high, and the breaking strength is high. The weak material is not damaged, and furthermore, the ultraviolet light cleaning chamber is connected to the cleaning chamber so as to be adjacent to the cleaning tank used in the final cleaning step in the cleaning tank. By performing the optical cleaning, there is an advantage that the cleanliness is improved.

A moving path through which an object to be cleaned moves between the cleaning chambers; an opening / closing shutter provided between the cleaning chamber and the moving paths; and a shutter between the cleaning chamber and the ultraviolet light cleaning chamber. It is preferable to further provide an opening / closing shutter installed in the cleaning chamber and a slow cooling chamber installed between the cleaning chamber and the ultraviolet light cleaning chamber for cooling an object to be cleaned (Claim 2).
By providing partitions between the cleaning tanks and between the cleaning tanks and between the cleaning tanks and the ultraviolet light cleaning chamber, it is possible to enhance the heat retaining effect of the cleaning tanks and easily control the temperature gradient. In addition, by providing a moving path for the object to be cleaned and a slow cooling chamber, it is possible to prevent a chemical solution from being brought in between the cleaning tanks and to impart a desired temperature gradient to the object to be cleaned, thereby efficiently obtaining high cleanliness. Can be.

A temperature sensor for measuring a temperature in the moving path and an atmosphere in the annealing room; and a temperature sensor in the moving path and an atmosphere in the annealing room based on a signal from the temperature sensor. Temperature adjusting means for adjusting;
It is preferable to further provide conveying means for moving an object to be cleaned in the cleaning chamber, the cleaning tank, the moving path, the annealing chamber, and the ultraviolet light cleaning chamber (Claim 3). With this, the temperature in the moving path and the temperature of the atmosphere in the annealing room are measured by the temperature sensor and adjusted by the temperature adjusting means, so that a desired temperature gradient is applied to the object to be cleaned. Further, cost reduction can be realized by providing a conveying means for moving the object to be cleaned and automating the same.

Each of the moving paths includes a device for preventing a watermark, and a predetermined cleaning tank in the cleaning tank includes an ultrasonic generator for performing ultrasonic cleaning. 4) is preferred. Thus, it is possible to prevent a decrease in cleanliness due to drying of the droplets, and to further improve the cleanliness by performing ultrasonic cleaning. Further, the device for preventing the watermark is a water jet device, the temperature adjusting means of the moving path is a heat exchanger for changing the temperature of the liquid used in the water jet device, the washing chamber and the The temperature control means of the annealing room is an air conditioner for changing the temperature of the gas sent to the cleaning room and the annealing room.
Is preferred. This can prevent a decrease in cleanliness due to the drying of the droplets, and can also reduce the number of cleaning tanks by also performing rinsing cleaning, and can impart a desired temperature gradient to the object to be cleaned. Thus, high cleanliness can be obtained efficiently.

Further, methylene chloride, N-methyl-2-pyrrolidone (NM)
One liquid among a mixed solution of P), an additive and pure water, an alkaline aqueous solution, a neutral cleaning solution, an acidic cleaning solution, or isopropyl alcohol or isopropyl alcohol vapor is used, and the liquid used in the water jet device is water. One of an electrolytic ion solution, an organic solvent or an O ₃ aqueous solution, and the gas sent to the cleaning chamber and the slow cooling chamber is one of clean air, active oxygen or N ₂ ( Claim 6) is preferred. This allows
High cleanliness can be obtained efficiently.

Further, the cleaning tank and the moving path are provided with 5
Cleaning tanks and four moving paths arranged between the respective cleaning tanks. The five cleaning tanks and the four moving paths comprise a first cleaning tank, A moving path, a second cleaning tank, a second moving path, a third cleaning tank, a third moving path, a fourth cleaning tank, a fourth moving path, and a fifth cleaning tank are arranged, and the first cleaning tank is used in the tank. The washing medium used is methylene chloride or N-
A washing tank that is a mixed solution of methyl-2-pyrrolidone (NMP), an additive, and pure water; a second washing tank is a washing tank in which a washing medium used in the tank is an alkaline aqueous solution or a neutral washing solution; The third cleaning tank is a cleaning tank in which the cleaning medium used in the tank is an acidic cleaning liquid, the fourth cleaning tank is a cleaning tank in which the cleaning medium used in the tank is isopropyl alcohol, and the fifth cleaning tank is isopropyl alcohol. The liquid used in the water jet device in the first moving path is an organic solvent, and the liquid used in the water jet device in the second moving path is water or an electrolytic ionic solution. water liquid used in jet device is water or an electrolytic ion solution, a fourth that liquid used in a water jet device of the mobile channel is O ₃ aqueous solution (claim 7 It is preferred. Thereby, high cleanliness can be obtained efficiently.

It is preferable that the object to be cleaned is a material having a linear expansion coefficient of 15 × 10 ⁻⁶ or more among optical materials usable in the ultraviolet region. As a result, of the optical materials usable in the ultraviolet region, the coefficient of linear expansion is 15 × 1
0 ^-6 or more materials can be cleaned without damaging the. A typical example of such a material is a fluoride crystal or a fluoride glass (claim 9). Thereby, the fluoride crystal or the fluoride glass can be cleaned without being damaged.

In the cleaning method according to the present invention, among the optical materials usable in the ultraviolet region, the coefficient of linear expansion is 15 × 10 ^−6.
In the above-described cleaning method for cleaning the material, the optical member is cleaned in each of a plurality of cleaning tanks having a cleaning liquid, and in the final cleaning step, ultraviolet light cleaning is performed, and the temperature of the cleaning liquid and the vicinity of the cleaning tank. Atmospheric temperature difference is ± 10
It is within ° C (claim 10).

According to the above-described cleaning method, since the difference between the temperature of the cleaning liquid and the temperature of the atmosphere near the cleaning tank is small, the linear expansion coefficient of the optical material usable in the ultraviolet region is 15 × 10 ^−6.
There is an advantage that the above materials are not damaged, and that the cleanliness is improved by performing the ultraviolet light cleaning. When cleaning is performed in the cleaning tank, ultrasonic cleaning is performed, the frequency of the ultrasonic wave is within a range of 10 kHz to 50 kHz, and the cleaning time is within 10 seconds to 5 minutes. 11) is preferred. Thus, it is possible to prevent the generation of etch pits on the surface of the object to be cleaned due to the ultrasonic cleaning.

Preferably, isopropyl alcohol vapor cleaning is added (claim 12). Thereby, high cleanliness can be obtained. A typical example of such a material is a fluoride crystal or a fluoride glass (claim 13). Thereby, the fluoride crystal or the fluoride glass can be cleaned without being damaged.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a cleaning apparatus and a cleaning method for a material having a high linear expansion coefficient and a low breaking strength among optical materials usable in the ultraviolet region, particularly a material having a linear expansion coefficient of 15 × 10 ^-6 or more. And examples of the material include fluoride crystals and fluoride glass.

An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 and FIG. 2 are configuration diagrams showing a cleaning apparatus of the present invention, and are connected at a portion A-B in the figure to form one apparatus. The cleaning apparatus shown in FIGS.
1, the first cleaning chamber 23, the second cleaning chamber 33, the third cleaning chamber 3
4, a fourth cleaning chamber 37, a fifth cleaning chamber 39, and a first cleaning tank 24, a second cleaning tank 35, a third cleaning tank 36, a fourth cleaning tank 38, A first moving path 27, a second moving path 56, a third moving path 57, a fourth moving path 58 provided between the cleaning tank 40 and the cleaning chamber so as to separate the respective cleaning chambers; The cooling room 41 includes a cooling room 41, a second annealing room 42, a third annealing room 43, a holder installation room 45, an ultraviolet light cleaning room 48, and a rear room 50. Each cleaning tank contains a cleaning medium for cleaning an object to be cleaned.

Each of the moving paths 27, 56, 57 and 58 is provided with a heat exchanger capable of adjusting the temperature of the liquid used in the water jet device as a temperature adjusting means in order to perform rinsing and prevent a watermark. Water jet devices 32a, 32b, 32c, 32d are provided. Some water jet devices wash high-pressure liquid from nozzles to clean holes in machine parts.The water jet device of this device is used for rinsing to prevent watermarks. Therefore, it is not necessary to apply high pressure to the liquid ejected from the nozzle. Water jet devices 32a, 32b, 32c,
As the liquid of 32d, water, an electrolytic ion solution, an organic solvent, and an O ₃ (ozone) aqueous solution are selectively used. The liquid of the water jet devices 32a, 32b, 32c, 32d is
The temperature is adjusted by a heat exchanger (not shown) which is a temperature adjusting means.

As a temperature adjusting means for adjusting the temperature of the atmosphere in the front room, each washing room and each slow cooling room, an air conditioner for adjusting the temperature of the gas to be sent is used. The gas sent to the front room, each cleaning room, each slow cooling room, and the rear room is one of clean air, active oxygen, and N ₂ . The cleaning medium used for each cleaning tank is a mixed solution of methylene chloride, N-methyl-2-pyrrolidone (NMP), an additive and pure water, an alkaline cleaning solution, a neutral cleaning solution, an acidic cleaning solution or isopropyl alcohol (IPA). One liquid or IPA vapor is used.

Each of the moving paths includes shutters 28a, 28b, 28c, 28d, 28e, 28f,
28g and 28h are provided. Fifth cleaning room 3
An opening / closing shutter 28i is provided between the first cooling room 9 and the first cooling room 41. These opening / closing shutters enhance the heat retaining effect of the cleaning tank, and facilitate control of the temperature gradient. UV light cleaning room 48, holder installation room 45 and rear room 50
Opening / closing shutters 28j and 28k are provided therebetween.

The first cleaning tank 24, the second cleaning tank 35, the third cleaning tank 36, and the fourth cleaning tank 38 include ultrasonic generators 62a, 62b, 62c for performing ultrasonic cleaning in each cleaning tank. 6
2d is attached. Each washing room 23 including the front room 21,
Temperature sensors 29a, 29b, 29c, 29d, and 29 are provided in 33, 34, 37, and 39 and the respective slow cooling chambers 41, 42, and 43.
e, 29f, 29g, 29h, and 29i. First cleaning tank 24, second cleaning tank 35, third cleaning tank 36
Is provided with a temperature sensor (not shown) for measuring the temperature of the cleaning liquid. A signal from each temperature sensor is transmitted to the temperature control device 30. Each cleaning room 23, 33, 34, 3
7, 39 and the temperature of the atmosphere in each of the slow cooling chambers 41, 42, 43, the temperature of the liquid jetted from the water jet device in each of the moving paths 27, 56, 57, 58,
The temperature of the cleaning medium in 35, 36, 38, 40 is feedback-controlled by the temperature control device 30 so that the temperature measured by each temperature sensor becomes the set temperature. The difference between the temperature of the cleaning medium in the first cleaning tank 24, the second cleaning tank 35, the third cleaning tank 36, and the temperature of the atmosphere in each cleaning chamber in which each cleaning tank is installed is ± It shall be within 10 ° C.

The cleaning device 22 includes transport units 26a, 26b, 26c, 26d, and 2 as transport means for moving the object to be cleaned.
6e, autoloaders 31a, 31b, 31c, 31d,
31e, 31f are provided, and these are anterior chamber, each washing room, each washing tank, each moving path, each slow cooling room, holder installation room, ultraviolet light washing room, rear room at an arbitrary speed by time control. The cleaning holder is controlled to move.

Hereinafter, a cleaning apparatus and a cleaning method according to the present invention will be described in the order of cleaning steps. Objects to be cleaned 20a, 20b,
20c, 20d, and 20e are cleaning holders 25a, 25b, and 25e, respectively, for easy movement in the cleaning device.
c, 25d, and 25e. In the embodiment of the present invention, the objects to be cleaned 20a, 20b, 20c, 20d,
Reference numerals 20e and 20f denote fluorite lenses made of a crystalline material used in the vacuum ultraviolet region. The arrow of the cleaning device 22 in FIG. 1 indicates the movement path of the object to be cleaned.

First, the object to be cleaned 20a is conveyed to the cleaning device 22, and is heated in the front chamber 21 to about -10 ° C. with respect to the temperature of the atmosphere in the first cleaning chamber 23. The cleaning medium of the first cleaning tank 24 is a substitute solution of tricrene, a substitute solution of trichloroethane, or a substitute solution of chlorofluorocarbon. Specifically, for example, there is a mixed solution of methylene chloride, N-methyl-2-pyrrolidone (NMP), an additive and pure water, and the like.
This apparatus uses methylene chloride. First cleaning tank 24
The object of the present invention is to remove a pitch for fixing the lens at the time of polishing and a protective film applied to the lens surface when the lens is removed from the polishing jig after the polishing. For example, if the liquid temperature of the first cleaning tank 24 is 50
℃, the temperature of the atmosphere in the first cleaning chamber 23 is 40 ℃
To 50 ° C., and the temperature of the atmosphere in the front chamber 21 is 3
It is controlled at 0 ° C to 40 ° C. Approximately 30 ° C-40 in front room 21
The object to be cleaned 20a heated to ° C. is moved together with the mounted cleaning holder 25a from the front chamber 21 to the first cleaning chamber 23 and then from the first cleaning chamber 23 to the first cleaning tank 24 by the transport unit 26a. Can be

After the contaminants generated during polishing, mainly the pitch and the protective film, are removed in the first cleaning tank 24, the object to be cleaned is lifted from the first cleaning tank 24 to the first cleaning chamber by the transport section 26a and transported. The part 26a stops before the first moving path 27. Then, the opening / closing shutter 28a is opened, and
0a is conveyed to the first moving path 27 by the autoloader 31a. A water jet device is arranged in the first moving path 27. The liquid of the water jet device 32a is preferably an organic solvent, for example, IPA, methanol or the like. This apparatus uses IPA. The temperature of the IPA is controlled between 40C and 50C. After radiating IPA from the water jet device 32a to the object to be cleaned 20a for a certain period of time, the autoloader 31a moves and the open / close shutter 2 is opened.
8b opens.

The cleaning holder 25a on which the object to be cleaned 20a is placed is attached to the transport section 26b. The transport section 26b moves in the second cleaning chamber 33. Cleaning holder 25
The object to be cleaned 20a placed on the second cleaning tank 35
Immersed in As a cleaning medium for the second cleaning tank 35, an alkaline cleaning liquid or a neutral cleaning liquid is preferable. In this apparatus, an alkaline cleaning liquid is used, and the liquid temperature is set to about 50 ° C. The second cleaning tank 35 has an ultrasonic generator 62b.
Is provided, thereby applying ultrasonic waves having a frequency of 10 kHz to 50 kHz to perform ultrasonic cleaning. The cleaning time is within 10 seconds to 5 minutes. If the cleaning time is less than 10 seconds, the dirt is not completely removed, and if the cleaning time is more than 5 minutes, the object to be cleaned may be damaged. The temperature of the atmosphere in the second cleaning chamber 33 is controlled at 40 ° C to 50 ° C.

After the washing is completed, the transport section 26b is moved to the second moving path 5
6, the opening / closing shutter 28c is opened, and the cleaning holder on which the object to be cleaned is placed is placed on the autoloader 31b.
To be placed. The water jet device 32b is disposed in the second moving path 56, as in the first moving path 27. As the liquid of the water jet device 32b, water or
Electrolytic ionic solutions are preferred. This device uses water,
The liquid temperature is controlled at 40 ° C to 50 ° C. After the object to be cleaned stops on the second moving path 56 for an arbitrarily set time, the autoloader 31b moves and the opening / closing shutter 28d opens. The cleaning holder 25b on which the object to be cleaned 20b is placed is
It is attached to the transport section 26c.

The transport section 26c moves in the third cleaning chamber 34,
The object to be cleaned 20b placed on the cleaning holder 25b is immersed in the third cleaning tank 36. The cleaning medium in the third cleaning tank 36 is preferably an acidic cleaning liquid capable of etching the fluorite lens as the cleaning object 20b, for example, an aqueous solution of dilute nitric acid, dilute sulfuric acid, dilute hydrochloric acid, or the like. In this apparatus, dilute hydrochloric acid is used, and the liquid temperature is 50 ° C. Similarly to the second cleaning tank 35, ultrasonic waves having a frequency of 10 kHz to 50 kHz are given by the ultrasonic generator 62c to perform ultrasonic cleaning. Washing time is 10
It is about seconds to 5 minutes. If the cleaning time is less than 10 seconds, the dirt is not completely removed, and if the cleaning time exceeds 5 minutes, the object to be cleaned may be damaged. The ultrasonic generators 62a, 62b, 62c, and 62d attached to each cleaning tank can increase the frequency up to 100 kHz. In the case of crystalline materials such as fluorite, etch pits are generated on the surface due to the cavitation (bubbles) of the ultrasonic cleaning, and light is scattered on the lens surface by the etch pits. It is preferable to carry out the washing while suppressing the value of the number. Note that the temperature of the atmosphere in the third cleaning chamber 34 is controlled at 35 ° C to 45 ° C.

After the completion of cleaning in the third cleaning tank 34, the transport unit 2
6c moves to the front of the third moving path 57, the opening / closing shutter 28e opens, and the cleaning holder 28e on which the object 20b is placed is placed on the autoloader 31c. As the liquid of the water jet device 32c of the third moving path 57, water or an electrolytic ionic solution is preferable. In this apparatus, water is used, and the liquid temperature is controlled at 40 ° C to 50 ° C. After the object to be cleaned 20b stops on the third moving path 57 for an arbitrarily set time, the autoloader 31c moves to open the opening / closing shutter 28f. Then, the cleaning holder 25b on which the object to be cleaned 20b is placed is attached to the transport section 26d.

The transport section 26d moves in the fourth cleaning chamber 37,
The object to be cleaned 20b is immersed in the fourth cleaning tank. The temperature of the atmosphere in the fourth cleaning chamber 37 is controlled at 25 ° C to 35 ° C. The cleaning medium of the fourth cleaning tank 38 uses IPA,
The liquid temperature is normal temperature. The cleaning time is about 10 seconds to 5 minutes. After the cleaning, the transport unit 26d moves to the position before the fourth moving path 58, the opening / closing shutter 28g opens, and the cleaning holder on which the object to be cleaned is placed is placed on the autoloader 31d. The water jet device 32d of the fourth moving path 58
As the liquid, an O ₃ aqueous solution is preferable. The liquid temperature of the O ₃ aqueous solution is initially about 35 ° C. to 50 ° C., and 40 ° C. to 60 ° C.
Gradually increase the liquid temperature until After stopping for an arbitrarily set time in the fourth moving path 58, the autoloader 31d moves to open and close the shutter 28h, and the cleaning holder 25b on which the object 20b is mounted is attached to the transport unit 26e.

The transport section 26e moves in the fifth cleaning chamber 39,
The object to be cleaned 20c is immersed in the fifth cleaning tank 40. The temperature of the atmosphere in the fifth cleaning chamber 39 is controlled at 50 ° C. to 60 ° C., and the cleaning medium of the fifth cleaning tank 40 is IPA vapor,
The fifth cleaning tank 40 is an IPA vapor cleaning tank that performs IPA vapor cleaning (IPA vapor cleaning). The temperature of the IPA vapor is about 80C to 85C. Cleaning time is 10 seconds to 5
Minutes. If the cleaning time is less than 10 seconds, the dirt is not completely removed, and if the cleaning time exceeds 5 minutes, the object to be cleaned may be damaged.

After the cleaning is completed, the transport section 26e moves to a position before the first slow cooling chamber 41 for cooling the object to be cleaned, the opening / closing shutter 28i is opened, and the cleaning holder 25d on which the object to be cleaned 20d is placed is moved. , Is placed on the autoloader 31e. The temperature of the atmosphere in the first annealing room 41 is 70 ° C to 60 ° C.
° C., the object to be cleaned is a first annealing room 41, a second annealing room 42,
After passing through the third slow cooling chamber 43, the object to be cleaned is gradually cooled until the temperature thereof reaches about 30 ° C.

Next, the upper holder 46 is transported from the cleaning holder storage chamber 44 in the holder installation chamber 45, and the upper holder 46 is moved to the object 20e to be cleaned by the holder installation device 47.
Is mounted so as to cover the cleaning holder 25e on which the is mounted. The cleaning holders provided above and below the object to be cleaned in the holder installation chamber 45 are rotated by 90 ° and placed on the autoloader 31f. Then, the opening / closing shutter 28j is opened, and the object 20f is moved to the ultraviolet light cleaning chamber (UV cleaning chamber) 48. The object 20f to be cleaned is stopped in the UV cleaning chamber 48, the UV lamp 49 is turned on, and the object 20f to be cleaned is subjected to UV cleaning. The cleaning time is about 1 minute to 30 minutes. If the cleaning time is less than 1 minute, the dirt is not completely removed, and if the cleaning time is 30 minutes, the dirt is sufficiently removed. An oxygen cylinder 51b is provided above the UV cleaning chamber 48. By feeding active oxygen from the oxygen inlet 59 during the UV cleaning, organic dirt adhering to the surface of the fluorite lens which is the object to be cleaned 20f is removed, and the surface of the fluorite lens is activated. Excess gas in the UV cleaning chamber is exhausted from the exhaust port 61. The reason for rotating the cleaning holder by 90 ° in the holder installation room 45 is that the UV cleaning room 4
This is for efficiently irradiating the object to be cleaned with UV light emitted from the UV lamp 49 installed on the upper part of the cleaning object 8.
After the cleaning, the opening / closing shutter 28k is opened, and the cleaning holder is transported to the rear chamber 50.

In the front room, each cleaning room, each cooling room, and the rear room, clean air, active oxygen from the oxygen cylinder 51a, or N ₂ from the nitrogen cylinder 55 is supplied to the front room, each cleaning room, Air conditioners 52a, 52b, 52c, 52d, 52e, 52f,
The air is blown while being controlled to a suitable temperature at 52g, 52h, and 52i. The air conditioner 52 is connected to an air pipe 53. The air pipe 53 is connected to a clean air device 54, an oxygen cylinder 51a, and a nitrogen cylinder 55. The clean air device 54 takes in outside air, and the taken-in outside air is removed of dust and the like by a built-in air filter and the like.
The air volume is adjusted and sent to the air conditioner 52. In addition, the front room, each cleaning room, each slow cooling room, and the rear room have a dust collection efficiency of 99.99% or more for particles of 0.1 μm and a class 100.
The atmosphere is to keep the following cleanliness,
Filled with _two . Since the clean environment is always maintained, contamination of the surface of the object to be cleaned is suppressed.

Preferably, the transport units 26a, 26b, 26
c, 26d, 26e, autoloaders 31a, 31b, 3
1c, 31d, 31e, 31f, open / close shutter 28
a, 28b, 28c, 28d, 28e, 28f, 28
By automatically controlling g, 28h, 28i, 28j, and 28k, the cost can be reduced by automating the cleaning.

[0040]

As described above, the cleaning apparatus of the present invention comprises a plurality of cleaning tanks, a temperature sensor for measuring the temperature of the cleaning medium in a predetermined cleaning tank and the atmosphere in the cleaning chamber, and a signal from the temperature sensor. Temperature control means for controlling the temperature of the cleaning medium in the cleaning tank and the atmosphere in the cleaning chamber based on the temperature of the object to be cleaned in a certain temperature range or a predetermined temperature gradient throughout the entire cleaning process so as to eliminate damage due to the temperature difference. It is possible to keep in. The temperature of the atmosphere in the cleaning chamber and the temperature of the liquid (cleaning liquid) in the cleaning tank are measured, and the difference between them is ± 10 ° C.
Within this range, breakage due to a temperature difference can be eliminated even when a material having a linear expansion coefficient of 15 × 10 ⁻⁶ or more among optical materials usable in the ultraviolet region as the object to be cleaned. In addition, high cleanliness can be obtained by performing ultraviolet light cleaning. The present invention does not require the skill of hand wiping because the cleaning is performed by the cleaning device.

By providing a moving path and an opening / closing shutter between the cleaning tanks and separating them, the heat retaining effect of the cleaning tank can be enhanced and the temperature gradient can be easily controlled. Further, by providing a moving path for the object to be cleaned, it is possible to prevent a chemical solution from being brought into between the cleaning tanks, and it is possible to efficiently obtain high cleanliness. Furthermore, by providing a slow cooling chamber that gradually lowers the temperature of the object to be cleaned between the final cleaning tank and the ultraviolet light cleaning chamber,
Even if an optical material that can be used in the ultraviolet region as the object to be cleaned has a linear expansion coefficient of 15 × 10 ⁻⁶ or more, breakage due to a sharp decrease in temperature can be eliminated.

In addition, a device for preventing watermarks is provided in the moving path to prevent a decrease in cleanliness due to drying of the droplets and also to perform the rinsing cleaning, thereby providing an effect of reducing the number of cleaning tanks. Further, by providing an ultrasonic generator for performing ultrasonic cleaning in a predetermined cleaning tank, the cleaning efficiency can be increased. However, if the material to be cleaned is a material having a linear expansion coefficient of 15 × 10 ⁻⁶ or more among the optical materials that can be used in the ultraviolet region, these optical materials have low destructive strength. Number is 10 kh
Within a range of z to 50 kHz, and a cleaning time of 10 seconds to 5 seconds.
It is preferably within minutes.

By applying the cleaning apparatus and the cleaning method according to the embodiment of the present invention, the conventional problems can be overcome and the cleanliness of the fluorite lens surface can be improved.
Since scattering and absorption of light due to surface contamination are greatly reduced, optical characteristics (transmittance) can be further improved,
In addition, when the optical thin film such as an antireflection film is coated by activating the surface of the fluorite lens, there is an effect that the adhesion of the optical thin film to the surface of the fluorite lens is improved.
Further, by performing the temperature control, there is an effect that damage to the fluorite lens can be reduced, the yield can be improved, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a cleaning apparatus of the present invention.

FIG. 2 is a configuration diagram showing a cleaning apparatus of the present invention.

FIG. 3 is a configuration diagram showing a conventional optical component cleaning apparatus.

FIG. 4 is a view showing a conventional cleaning method for manually wiping optical components.

FIG. 5 is a configuration diagram of a conventional wet processing apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cleaning apparatus 2 First cleaning tank 3 Second cleaning tank 4 Third cleaning tank 5 Fourth cleaning tank 6 Fifth cleaning tank 7 Sixth cleaning tank 8 Ultrasonic generator 9 Liquid temperature control device 10 Wiping cloth 11 Fingertip 12a 12b Object to be cleaned 13 Rotary table 14 Wafer 15 Chemical solution 16 Heating chamber 17 Carrier 18 Warm air inlet 19 Exhaust port 20a, 20b, 20c, 20d, 20e, 20f Fluorite lens 21 Front chamber 22 Cleaning device 23 First cleaning chamber 24 First cleaning tank 25a, 25b, 25c, 25d, 25e Cleaning holder 26a, 26b, 26c, 26d, 26e Transport unit 27 First moving path 28a, 28b, 28c, 28d, 28e, 28f, 2
8g, 28h, 28i, 28j, 28k Open / close shutter 29a, 29b, 29c, 29d, 29e, 29f, 2
9g, 29h, 29i Temperature sensor 30 Temperature controller 31a, 31b, 31c, 31d, 31e, 31f
Autoloader 32a, 32b, 32c, 32d Water jet device 33 Second cleaning chamber 34 Third cleaning chamber 35 Second cleaning tank 36 Third cleaning tank 37 Fourth cleaning chamber 38 Fourth cleaning tank 39 Fifth cleaning chamber 40 Fifth cleaning Tank 41 First annealing room 42 Second annealing room 43 Third annealing room 44 Cleaning holder storage room 45 Holder installation room 46 Upper holder 47 Holder installation device 48 Ultraviolet light cleaning room 49 UV lamp 50 Rear room 51a, 51b Oxygen Cylinders 52a, 52b, 52c, 52d, 52e, 52f, 5
2g, 52h, 52i Air conditioner 53 Air piping 54 Clean air device 55 Nitrogen cylinder 56 Second moving path 57 Third moving path 58 Fourth moving path 59 Oxygen inlet 60 Exhaust valve 61 Exhaust outlet 62a, 62b, 62c, 62d Sound wave generator

Claims (13)

[Claims] A cleaning chamber having a cleaning medium for cleaning an object to be cleaned; a cleaning chamber in which the cleaning tank is installed; a temperature of a cleaning medium in a predetermined cleaning tank in the cleaning tank; Temperature sensors for measuring the temperature of the atmosphere in the cleaning chamber, temperature adjusting means for adjusting the temperature of the cleaning medium and the temperature of the atmosphere in the cleaning chamber based on signals from the temperature sensors, A cleaning apparatus comprising: an ultraviolet light cleaning chamber disposed adjacent to a cleaning tank used in the final cleaning step and connected to a cleaning chamber related to the cleaning tank used in the final cleaning step. 2. The cleaning apparatus according to claim 1, wherein a moving path through which an object to be cleaned moves between each of the cleaning chambers, an opening / closing shutter provided between the cleaning chamber and the moving paths, An opening / closing shutter provided between a cleaning room and the ultraviolet light cleaning room; and a slow cooling room provided between the cleaning room and the ultraviolet light cleaning room for cooling an object to be cleaned. Characterized cleaning equipment. 3. The cleaning device according to claim 2, wherein a temperature sensor for measuring a temperature in the moving path and a temperature of an atmosphere in the cooling room, and a temperature in the moving path based on a signal from the temperature sensor. And a temperature adjusting unit that adjusts the temperature of the atmosphere in the annealing room; and a transport unit that moves an object to be cleaned in the cleaning room, the cleaning tank, the moving path, the annealing room, and the ultraviolet light cleaning room, A cleaning device, further comprising: 4. The cleaning apparatus according to claim 3, wherein each of the moving paths includes a device for preventing a watermark, and a predetermined cleaning tank in the cleaning tank performs ultrasonic cleaning. A cleaning device comprising a generator. 5. The cleaning device according to claim 4, wherein the device for preventing the watermark is a water jet device, and the temperature adjustment means of the moving path adjusts a temperature of a liquid used in the water jet device. A cleaning device, wherein the temperature control means of the cleaning chamber and the annealing chamber is an air conditioner for changing a temperature of gas sent to the cleaning chamber and the annealing chamber. . 6. The cleaning apparatus according to claim 5, wherein methylene chloride, N
A liquid solution of a mixture of methyl-2-pyrrolidone (NMP), an additive and pure water, an alkaline cleaning solution, a neutral cleaning solution, an acidic cleaning solution, or isopropyl alcohol, or vapor of isopropyl alcohol; Is one of water, an electrolytic ion solution, an organic solvent or an O ₃ aqueous solution, and the gas sent to the cleaning chamber and the slow cooling chamber is clean air, active oxygen or N ₂ . A cleaning device, characterized by being one of the following. 7. The cleaning apparatus according to claim 6, wherein the cleaning tank and the moving path include five cleaning tanks and four moving paths disposed between the respective cleaning tanks. The five cleaning tanks and the four moving paths are, in order of the cleaning process, a first cleaning tank, a first moving path, a second cleaning tank, a second moving path, a third cleaning tank, a third moving path, a fourth moving path. A cleaning tank, a fourth moving path, and a fifth cleaning tank are arranged. The first cleaning tank uses methylene chloride as a cleaning medium in the tank.
Alternatively, the washing tank is a mixed solution of N-methyl-2-pyrrolidone (NMP), an additive and pure water, and the second washing tank is a washing tank in which the washing medium used in the tank is an alkaline washing solution or a neutral washing solution. The third cleaning tank is a cleaning tank in which the cleaning medium used in the tank is an acidic cleaning liquid, the fourth cleaning tank is a cleaning tank in which the cleaning medium used in the tank is isopropyl alcohol, and the fifth cleaning tank. The tank is an isopropyl alcohol vapor washing tank. The liquid used in the water jet device on the first moving path is an organic solvent, and the liquid used in the water jet device on the second moving path is water or an electrolytic ionic solution. The liquid used in the water jet device on the third moving path is water or an electrolytic ionic solution, and the liquid used in the water jet device on the fourth moving path is O ₃ aqueous solution. A cleaning device characterized by being a liquid. 8. The method according to claim 1, wherein
In the cleaning apparatus, the object to be cleaned is an optical material usable in an ultraviolet region.
Linear expansion coefficient is 15 × 10 ^-6Characterized by the above materials
Cleaning equipment. 9. The cleaning apparatus according to claim 8, wherein the object to be cleaned is a fluoride crystal or a fluoride glass. 10. A cleaning method for cleaning a material having a linear expansion coefficient of 15 × 10 ⁻⁶ or more among optical materials usable in an ultraviolet region, wherein the optical material is cleaned in each of a plurality of cleaning tanks having a cleaning liquid. A cleaning method, wherein ultraviolet light cleaning is performed in a final cleaning step, and a difference between a temperature of the cleaning liquid and a temperature of an atmosphere near the cleaning tank is within ± 10 ° C. 11. The cleaning method according to claim 10, wherein when cleaning is performed in the cleaning tank, ultrasonic cleaning is performed, a frequency of ultrasonic waves is in a range of 10 kHz to 50 kHz, and a cleaning time is set. Is a cleaning method characterized by being within 10 seconds to 5 minutes. 12. The cleaning method according to claim 10, wherein isopropyl alcohol vapor cleaning is added. 13. The cleaning method according to claim 10, wherein the optical material is a fluoride crystal or a fluoride glass.