WO2016163004A1

WO2016163004A1 - Cleaning apparatus with co2 recycling and operation method therefor

Info

Publication number: WO2016163004A1
Application number: PCT/JP2015/061121
Authority: WO
Inventors: 敦氏家; 本多　祐二; 由佳利三上
Original assignee: 株式会社ユーテック
Priority date: 2015-04-09
Filing date: 2015-04-09
Publication date: 2016-10-13
Also published as: JPWO2016163004A1

Abstract

[Problem] To provide a cleaning apparatus with CO2 recycling for which the amount of CO2 used can be reduced. [Solution] An embodiment of the present invention is a cleaning apparatus with CO2 recycling: which is equipped with a chamber (27a), a first liquefied CO2 cylinder (51) for supplying CO2 into said chamber (27a), a discharge mechanism (23a) for discharging the CO2 inside said chamber (27a), liquefying mechanisms (73-74) for liquefying the CO2 discharged by the discharge mechanism (23a), and a second liquefied CO2 cylinder (52) for holding the CO2 liquefied by the liquefying mechanisms (73-74); and in which the CO2 held in the second liquefied CO2 cylinder (52) is fed into the chamber (27a), and an object to be cleaned is cleaned using CO2 supplied into the chamber (27a) from the first liquefied CO2 cylinder (51) or the second liquefied CO2 cylinder (52).

Description

Cleaning device with CO2 recycling and its operation method

The present invention relates to a cleaning apparatus with CO ₂ recycling and an operation method thereof.

FIG. 8 is a schematic diagram for explaining an example of a conventional cleaning apparatus.
This cleaning apparatus includes a cylinder (not shown) containing liquefied carbon dioxide (liquefied CO ₂ ) pressurized to 6 MPa, a nozzle 101 connected to the cylinder, and a cleaning chamber (not shown). It has a holding mechanism (not shown) for holding the substrate 102, a duct 104 having an intake port 104a, a blower (BLOWER), and a hepa filter (HEPA FILTER). The holding mechanism is a mechanism that holds the substrate 102 at a position where the surface (cleaning surface) of the substrate 102 is substantially parallel to the horizontal plane and the surface of the substrate 102 faces upward (a direction opposite to the direction of gravity).

The above cleaning apparatus operates as follows. Liquefied CO ₂ under pressure in the cylinder is supplied to the nozzle 101, the CO ₂ particles 103 that liquefied CO ₂ is injected into the cleaning chamber through the nozzle 101, the surface of the substrate 102 held by the holding mechanism By blowing, particles or the like adhering to the substrate 102 are blown away, and the blown particles or the like are removed by sucking from the suction port 104a on the side of the substrate 102 by a blower. Then, particles or the like passing through the duct 104 from the intake port 104a are captured by a hepa filter, and the gas from which the particles or the like are removed is supplied onto the substrate 102 again. The nozzle 101 is made of stainless steel, and the substrate 102 is, for example, a silicon wafer or a glass substrate after lift-off in a semiconductor process. A technique related to the above-described cleaning apparatus is disclosed in Patent Document 1.

In an apparatus for cleaning an object to be cleaned with CO ₂ , as described above, since CO ₂ particles once sprayed are not recycled, a large amount of liquefied carbon dioxide (liquefied CO ₂ ) is used when the amount of the object to be cleaned is large. become. Since the liquefied carbon dioxide gas for CO ₂ cleaning uses a high-purity carbon dioxide gas compared to a general grade (food grade) carbon dioxide gas, the running cost of the cleaning becomes remarkably high. For example, a general-grade carbon dioxide gas is 150 yen / kg, whereas a high-purity carbon dioxide gas used for semiconductor cleaning or the like is 3800 yen / kg.

Moreover, since CO ₂ after use is discharged into the atmosphere, there is a risk of causing environmental problems including global warming.

USP 6,099,396

An object of one embodiment of the present invention is to provide a cleaning device with CO ₂ recycling that can reduce the amount of CO ₂ used or an operation method thereof.

Hereinafter, various aspects of the present invention will be described.
[1] a chamber;
A first liquefied CO ₂ cylinder for supplying CO ₂ into the chamber;
A discharge mechanism for discharging the CO ₂ in the chamber;
A liquefaction mechanism for liquefying the CO ₂ discharged by the discharge mechanism;
A second liquefied CO ₂ cylinder containing CO ₂ liquefied by the liquefaction mechanism;
Comprising
The CO ₂ contained in the second liquefied CO ₂ cylinder is supplied into the chamber,
A cleaning apparatus with CO ₂ recycling, wherein an object to be cleaned is cleaned by CO ₂ supplied into the chamber from the first liquefied CO ₂ cylinder or the second liquefied CO ₂ cylinder.

[2] In the above [1],
It said second liquefied CO CO ₂ contained in the ₂ cylinder is supplied to the chamber, the CO ₂ in the chamber is discharged by the discharge mechanism, are liquefied by that discharged the CO ₂ is the liquefaction mechanism the third liquefied CO ₂ cylinder for containing the liquefied CO ₂ further comprising,
The third liquefied CO CO ₂ contained in the ₂ cylinder is supplied to the chamber, the CO ₂ in the chamber is discharged by the discharge mechanism, are liquefied by that discharged the CO ₂ is the liquefaction mechanism The liquefied CO ₂ is accommodated in the second liquefied CO ₂ cylinder,
A cleaning apparatus with CO ₂ recycling, wherein the object to be cleaned is cleaned with CO ₂ supplied from the third liquefied CO ₂ cylinder into the chamber.

[3] a chamber;
A second liquefied CO ₂ cylinder for supplying CO ₂ into the chamber;
A discharge mechanism for discharging the CO ₂ in the chamber;
A liquefaction mechanism for liquefying the CO ₂ discharged by the discharge mechanism;
A third liquefied CO ₂ cylinder containing CO ₂ liquefied by the liquefaction mechanism;
Comprising
The third liquefied CO CO ₂ contained in the ₂ cylinder is supplied to the chamber, the CO ₂ in the chamber is discharged by the discharge mechanism, are liquefied by that discharged the CO ₂ is the liquefaction mechanism , the liquefied CO ₂ is accommodated in the second liquefied CO ₂ cylinder,
A cleaning apparatus with CO ₂ recycling, wherein an object to be cleaned is cleaned by CO ₂ supplied into the chamber from the second liquefied CO ₂ cylinder or the third liquefied CO ₂ cylinder.

[4] In any one of [1] to [3] above,
The exhaust mechanism has a vacuum pump for evacuating the chamber,
It said second liquefied CO ₂ cylinder, the discharged from the vacuum pump, cleaning apparatus CO ₂ with recycling, characterized in that it is intended to accommodate the CO ₂ that is liquefied by the liquefaction mechanism.

[5] In any one of [1] to [3] above,
The exhaust mechanism has an exhaust fan for exhausting the chamber.
Said second liquefied CO ₂ cylinder, the exhaust fan is discharged from, CO ₂ cleaning apparatus with recycling, characterized in that it is intended to accommodate the CO ₂ that is liquefied by the liquefaction mechanism.

[6] In the above [4],
The vacuum pump, CO ₂ cleaning apparatus with recycling, characterized in that it comprises a dry pump or a mechanical booster pump.

[7] In the above [1] or [2],
A first path for supplying the CO ₂ from the first liquefied CO ₂ cylinder into the chamber, the switching between the second path for supplying the CO ₂ into the chamber from said second liquefied CO ₂ cylinder A cleaning apparatus with CO ₂ recycling, comprising a switching mechanism of 1.

[8] In any one of [1], [2] and [7] above,
A second switching mechanism disposed between the discharge mechanism and the second liquefied CO ₂ cylinder;
The second switching mechanism switches a third path for supplying the CO ₂ from the chamber to the second liquefied CO ₂ cylinder and a fourth path for exhausting the CO ₂ from the chamber to the exhaust port. A cleaning apparatus with CO ₂ recycling, characterized in that

[9] In the above [2] or [3],
The switch between the the fifth path for supplying the CO ₂ from the second liquefied CO ₂ cylinder into the chamber, the third liquefied CO for supplying the CO ₂ from ₂ bomb into the chamber sixth path A cleaning apparatus with CO ₂ recycling, characterized in that it has 3 switching mechanisms.

[10] In any one of [2], [3] and [9] above,
A fourth path is switched between a seventh path for supplying the CO ₂ from the chamber to the second liquefied CO ₂ cylinder and an eighth path for supplying the CO ₂ from the chamber to the third liquefied CO ₂ cylinder. A cleaning apparatus with CO ₂ recycling, comprising a switching mechanism.

[11] In the above [2],
A first path for supplying the CO ₂ from the first liquefied CO ₂ cylinder into the chamber, the switching between the second path for supplying the CO ₂ into the chamber from said second liquefied CO ₂ cylinder 1 switching mechanism;
A second switching mechanism that switches between a third path for supplying the CO ₂ from the chamber to the second liquefied CO ₂ cylinder and a fourth path for exhausting the CO ₂ from the chamber to an exhaust port;
The supply and the second liquefied CO ₂ from said cylinder first fifth path for supplying to the switching mechanism of the CO _2, the CO ₂ in the first switching mechanism from the third liquefied CO ₂ cylinder A third switching mechanism for switching between six routes;
The supply and the second from said switching mechanism of the second liquefied CO supplies the CO ₂ to ₂ cylinder seventh path, the CO ₂ in the third liquefied CO ₂ cylinder from said second switching mechanism A fourth switching mechanism for switching between eight routes;
Comprising
The second switching mechanism is disposed between the discharge mechanism and the second liquefied CO ₂ cylinder,
The third switching mechanism is disposed between the first switching mechanism and the second liquefied CO ₂ cylinder,
The fourth switching mechanism is disposed between the second switching mechanism and the second liquefied CO ₂ cylinder, and is a cleaning apparatus with CO ₂ recycling.

[12] In the above [7] or [11],
The first switching mechanism includes:
A first three-way valve having a first valve connected to the first liquefied CO ₂ cylinder, a second valve connected to the chamber, and a third valve connected to the second liquefied CO ₂ cylinder;
A first control unit for controlling the first three-way valve,
The first control unit opens the first valve and the second valve and closes the third valve when supplying the CO ₂ into the chamber from the first liquefied CO ₂ cylinder. And when the CO ₂ is supplied from the second liquefied CO ₂ cylinder into the chamber, the second valve and the third valve are opened and the first valve is closed. A cleaning device with CO ₂ recycling.

[13] In the above [8] or [11],
The second switching mechanism includes
A second three-way valve having a first valve connected to the exhaust mechanism, a second valve connected to the exhaust port, and a third valve connected to the second liquefied CO ₂ cylinder;
A second control unit for controlling the second three-way valve,
The second control unit opens the first valve and the third valve and closes the second valve when supplying the CO ₂ into the chamber from the first liquefied CO ₂ cylinder. Then, control is performed so that the CO ₂ in the chamber discharged by the discharge mechanism is accommodated in the second liquefied CO ₂ cylinder, and the first liquefied CO ₂ cylinder or the second liquefied CO ₂ cylinder is stored. wherein said chamber from when the CO ₂ does not supply, the opening of the first valve and the second valve, and the third valve closing control CO ₂ cleaning apparatus with recycling, which comprises as.

[14] In any one of the above [7], [8], [11] and [12]
A first weigh scale that measures the remaining amount of CO ₂ in the first liquefied CO ₂ cylinder by weight;
The first switching mechanism is configured such that when the remaining amount of CO ₂ in the first liquefied CO ₂ cylinder measured by the first weigh scale becomes the first weight%, the first switching mechanism is configured to perform the first switching from the first path. The cleaning apparatus with CO ₂ recycling is controlled to supply the CO ₂ into the chamber from the second liquefied CO ₂ cylinder by switching to the second path.

[15] In any one of [7], [8], [11] and [12] above,
A first pressure gauge that measures the remaining amount of CO ₂ in the first liquefied CO ₂ cylinder by pressure;
The first switching mechanism is configured such that when the remaining amount of CO ₂ in the first liquefied CO ₂ cylinder measured by the first pressure gauge becomes a first pressure, the second switching mechanism is configured to perform the second switching from the first path. The cleaning apparatus with CO ₂ recycling is controlled to supply the CO ₂ into the chamber from the second liquefied CO ₂ cylinder by switching to the path.

[16] In any one of [9] to [11] above,
A second weigh scale that measures the remaining amount of CO ₂ in the _second liquefied CO ₂ cylinder by weight;
When the remaining amount of CO ₂ in the _second liquefied CO ₂ cylinder measured by the second weigh scale becomes 2% by weight, the third switching mechanism is configured to release the fifth path from the fifth path. The cleaning apparatus with CO ₂ recycling is controlled so as to supply the CO ₂ from the third liquefied CO ₂ cylinder into the chamber by switching to the path of No. 6.

[17] In any one of [9] to [11] above,
A second pressure gauge for measuring the remaining amount of CO ₂ in the _second liquefied CO ₂ cylinder by pressure;
When the remaining amount of CO ₂ in the _second liquefied CO ₂ cylinder measured by the second pressure gauge becomes the second pressure, the third switching mechanism is configured to perform the sixth switching from the fifth path. The cleaning apparatus with CO ₂ recycling is controlled so as to supply the CO ₂ into the chamber from the third liquefied CO ₂ cylinder by switching to the path.

[18] In any one of [1] to [17] above,
A cleaning apparatus with CO ₂ recycling, comprising: a particle filter that removes particles in the discharge containing CO ₂ discharged by the discharge mechanism; and an organic filter that removes organic matter in the discharge.

[19] In the operation method of the cleaning apparatus with CO ₂ recycling according to any one of [1], [2], [7], [8] and [11] to [15],
Supplying CO ₂ into the chamber from said first liquefied CO ₂ cylinder, the said CO ₂ in the chamber is discharged by the discharge mechanism, liquefying the CO ₂ discharged by the discharge mechanism by the liquefaction mechanism And storing the CO ₂ liquefied by the liquefaction mechanism in the second liquefied CO ₂ cylinder,
Stop from the first liquefied CO ₂ cylinder for supplying CO ₂ into the chamber, by supplying CO ₂ from the second liquefied CO ₂ cylinder into the chamber, the CO ₂ in the chamber The operation method of the cleaning apparatus with CO ₂ recycling, wherein the discharging mechanism discharges the CO ₂ recycling mechanism.

[20] In the operation method of the cleaning apparatus with CO ₂ recycling according to [12],
The cleaning device with CO ₂ recycling is:
A second three-way valve having a first valve connected to the exhaust mechanism, a second valve connected to the exhaust port, and a third valve connected to the second liquefied CO ₂ cylinder;
A second control unit for controlling the second three-way valve,
The first control unit opens the first valve and the second valve of the first three-way valve and closes the third valve, and the second control unit performs the second three-way valve. open the first valve and the third valve, and the by closing the second valve to supply the CO ₂ from the first liquefied CO ₂ cylinder into the chamber, the CO ₂ in the chamber Discharging by the discharge mechanism, liquefying the CO ₂ discharged by the discharge mechanism by the liquefaction mechanism, storing the CO ₂ liquefied by the liquefaction mechanism in the second liquefied CO ₂ cylinder,
The first control unit opens the second valve and the third valve of the first three-way valve, and closes the first valve, so that the second liquefied CO ₂ cylinder enters the chamber. A method of operating a cleaning apparatus with CO ₂ recycling, wherein the CO ₂ is supplied.

According to one embodiment of the present invention, the amount of CO ₂ used can be reduced.

Is a schematic view showing a cleaning apparatus CO ₂ with recycle according to one aspect of the present invention. It is a figure which shows typically the vacuum type cleaning apparatus which concerns on 1 aspect of this invention. FIG. 3 is a cross-sectional view taken along the line 60-60 shown in FIG. Is a schematic view showing a cleaning apparatus CO ₂ with recycle according to one aspect of the present invention. It is a figure which shows typically the washing | cleaning apparatus which concerns on 1 aspect of this invention. FIG. 6 is a view of the holding mechanism and the exhaust mechanism shown in FIG. (A) is sectional drawing of the nozzle 11 shown in FIG. 5, (B) is the figure which looked at the nozzle shown to (A) from the base end side. It is a schematic diagram for demonstrating an example of the conventional washing | cleaning apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below.

[First Embodiment]
FIG. 1 is a schematic diagram illustrating a cleaning apparatus with CO ₂ recycling according to one embodiment of the present invention.

CO ₂ cleaning apparatus with recycling of FIG. 1, the vacuum chamber 27a, (also referred to as a first liquefied CO ₂ cylinder) replenishment CO ₂ cylinder 51, also referred to as a first recycle CO ₂ cylinder (second liquefied CO ₂ cylinder ) 52 and a second recycled CO ₂ cylinder (also referred to as a third liquefied CO ₂ cylinder) 53, and an object to be cleaned (not shown) is cleaned by CO ₂ supplied into the vacuum chamber 27 a. It is.

Moreover, CO ₂ cleaning apparatus with recycling, the first weighing scale (load cell) 54 for measuring the CO ₂ remaining in the replenishment CO ₂ cylinder 51 by weight, CO ₂ in the first recycle CO ₂ cylinder 52 A second weighing scale (load cell) 55 that measures the remaining amount by weight and a third weighing scale (load cell) 56 that measures the remaining amount of CO ₂ in the _second recycled CO ₂ cylinder 53 by weight are provided.

In addition, the cleaning apparatus with CO ₂ recycling includes a first pressure gauge (pressure gauge) 68 that measures the remaining amount of CO ₂ in the supplementary CO ₂ cylinder 51 by pressure, and a CO in the first recycled CO ₂ cylinder 52. _{A second} pressure gauge (pressure gauge) 69 that measures the remaining amount of ₂ by pressure, and a third pressure gauge (pressure gauge) 70 that measures the remaining amount of CO ₂ in the third recycled CO ₂ cylinder 53 by pressure. Have.

The cleaning apparatus with CO ₂ recycling includes first and second switching mechanisms and a switching unit 59 for switching the CO ₂ path. The first switching mechanism includes a first three-way valve 57 and a first control unit 60 that controls the first three-way valve 57, and the second switching mechanism includes a second three-way valve 58 and its A second control unit 61 for controlling the second three-way valve 58 is provided.

The replenishment CO ₂ cylinder 51 is a cylinder in which liquefied carbon dioxide (liquefied CO ₂ ) pressurized to 6 MPa is placed, and supplies CO ₂ into the vacuum chamber 27a. The replenishment CO ₂ cylinder 51 is connected to the first valve 64 of the first three-way valve 57 of the first switching mechanism by piping. The second valve 63 of the first three-way valve 57 is connected to one end of a valve 77 by piping, and the other end of the valve 77 is connected to the vacuum chamber 27a by piping. The third valve 62 of the first three-way valve 57 is connected to the switching unit 59 by piping, and the switching unit 59 is connected to the first and second recycled CO ₂ cylinders 52 and 53 by piping.

The first switching mechanism includes a first path for supplying CO ₂ from the replenishment CO ₂ cylinder 51 to the vacuum chamber 27a, and the first recycled CO ₂ cylinder 52 or the second recycled CO ₂ cylinder 53 to the vacuum chamber 27a. This is a mechanism for switching between the second path for supplying CO ₂ .

The vacuum chamber 27a is connected to a vacuum pump 23a as a discharge mechanism by piping, and the vacuum pump 23a evacuates the inside of the vacuum chamber 27a. The vacuum pump 23a may be a dry pump, or may include a dry pump and a mechanical booster pump.

The vacuum pump 23a is connected to the first valve 66 of the second three-way valve 58 of the second switching mechanism by piping, and the second valve 67 of the second three-way valve 58 is connected to the exhaust port 76 by piping. Has been. The third valve 65 of the second three-way valve 58 is connected to the particle filter 71 by piping. The second switching mechanism includes a third path for supplying CO ₂ from the vacuum chamber 27a to the first recycle CO ₂ cylinder 52 (ie, from the vacuum pump 23a to the particle filter 71), and from the vacuum chamber 27a to the exhaust port 76 ( That is, it is a mechanism for switching the fourth path for exhausting CO ₂ from the vacuum pump 23a to the exhaust port 76).

The particle filter 71 is a filter that removes particles such as inorganic contamination in the discharge containing CO ₂ discharged by the vacuum pump 23a.

The particle filter 71 is connected to an organic matter removal filter 72 by piping, and the organic matter removal filter 72 is a filter that removes organic matter in the discharged matter including CO ₂ discharged by the vacuum pump 23a.

Organic substance removal filter 72 is connected to the CO ₂ liquefying pressure pump 73 through a pipe, the CO ₂ liquefying pressure pump 73 is a CO ₂ gas which particles and organic matter has been removed by the

filter

71 and 72 pressurized It is a pump that pressurizes and liquefies.

The CO ₂ liquefaction pressure pump 73 is connected to a cooler 74 by piping, and the cooler 74 cools CO ₂ liquefied by the pump 73. A liquefaction mechanism is constituted by the cooler 74 and the CO ₂ liquefaction pressure pump 73. The cooler 74 is connected to a compressor 75 by piping, and the compressor 75 compresses the liquefied CO ₂ cooled by the cooler 74.

The compressor 75 is connected to the switching unit 59 by piping, and the switching unit 59 is connected to the first and second recycled CO ₂ cylinders 52 and 53 by piping.

The switching unit 59 has third and fourth switching mechanisms. The third switching mechanism includes a fifth path for supplying CO ₂ to the vacuum chamber 27a from the first recycle CO ₂ cylinder 52, and supplies the CO ₂ from the second recycle CO ₂ cylinder 53 to the vacuum chamber 27a sixth This is a mechanism for switching between routes. The fourth switching mechanism includes a seventh path for supplying CO ₂ from the vacuum chamber 27a to the first recycle CO ₂ cylinder 52 (ie, from the compressor 75 to the first recycle CO ₂ cylinder 52), and from the vacuum chamber 27a to the first recycle CO ₂ cylinder 52. This is a mechanism for switching the _second path for supplying CO ₂ to the second recycled CO ₂ cylinder 53 (ie, from the compressor 75 to the second recycled CO ₂ cylinder 53).

The third switching mechanism includes a third three-way valve (not shown) and a third control unit (not shown) that controls the third three-way valve. The first valve of the third three-way valve is connected to the first recycled CO ₂ cylinder 52, and the second valve of the third three-way valve is connected to the third valve 62 of the first three-way valve. The third valve of the third three-way valve is connected to the second recycled CO ₂ cylinder 53.

The fourth switching mechanism includes a fourth three-way valve (not shown) and a fourth control unit (not shown) that controls the fourth three-way valve. The first valve of the fourth three-way valve is connected to the compressor 75, the second valve of the fourth three-way valve is connected to the first recycled CO ₂ cylinder 52, and the fourth three-way valve The third valve is connected to the second recycle CO ₂ cylinder 53.

In this specification, “connect” or “connected” includes not only direct connection but also indirect connection.

Next, the operation method of the cleaning apparatus with CO ₂ recycling in FIG. 1 will be described.
<Supplying CO ₂ cylinder 51 → first recycling CO ₂ cylinder 52>
The replenishing CO ₂ cylinder 51 contains liquefied carbon dioxide (liquefied CO ₂ ) pressurized to 6 MPa. The valve 77 is closed so that CO ₂ is not supplied from the replenishing CO ₂ cylinder 51 into the vacuum chamber 27a. The second control unit 61 opens the first valve 66 and the second valve 67 of the second three-way valve 58 and closes the third valve 65. Then, the inside of the vacuum chamber 27a is evacuated by the vacuum pump 23a, and the exhaust is exhausted from the exhaust port 76, whereby the inside of the vacuum chamber 27a is brought to a predetermined pressure.

Next, the second control unit 61 opens the first valve 66 and the third valve 65 of the second three-way valve 58 and closes the second valve 67. The fourth control unit opens the first and second valves of the fourth three-way valve of the fourth switching mechanism of the switching unit 59 and closes the third valve. Accordingly, the fourth path for exhausting CO ₂ from the vacuum chamber 27a to the exhaust port 76 is closed, the third path for supplying CO ₂ from the vacuum chamber 27a to the switching unit 59 is opened, and the second three-way valve is opened. A seventh path for supplying CO ₂ from 58 to the first recycled CO ₂ cylinder 52 is opened. That is, the fourth path is switched to the third path by the second switching mechanism, and the seventh path is opened by the fourth switching mechanism. At the same time, the valve 77 is opened, the first control unit 60 opens the first valve 64 and the second valve 63 of the first three-way valve 57, and closes the third valve 62. Thus, CO ₂ is supplied from the replenishing CO ₂ cylinder 51 into the vacuum chamber 27a, and an object to be cleaned (not shown) in the vacuum chamber 27a is cleaned by this CO ₂ . This cleaning method for the object to be cleaned will be described in a second embodiment to be described later. The CO ₂ in the vacuum chamber 27a is discharged by the vacuum pump 23a, and the discharged CO ₂ is sent to the particle filter 71. In the discharge discharged by the vacuum pump 23a, particles such as inorganic contamination are contained in addition to CO ₂ . These particles are removed by the particle filter 71. Then, the discharge discharged by the vacuum pump 23 a is sent to the organic matter removal filter 72. The emission contains organic substances in addition to CO ₂ . This organic matter is removed by the organic matter removing filter 72. The CO ₂ from which particles and organic substances have been removed is pressurized and liquefied by a CO ₂ liquefaction pressure pump 73, the liquefied CO ₂ is cooled by a cooler 74, and the cooled liquefied CO ₂ is compressed by a compressor 75. And is collected and stored in the first recycle CO ₂ cylinder 52 through the switching unit 59.

Supplying CO ₂ into the vacuum chamber 27a from the replenishment CO ₂ cylinder 51 as described above, the after washing the object to be cleaned in the vacuum chamber 27a by CO _2, the vacuum pump 23a of CO ₂ in the vacuum chamber 27a The exhausted CO ₂ is liquefied, and the liquefied CO ₂ is collected in the first recycle CO ₂ cylinder 52. During the collection, the remaining amount of CO ₂ in the supplementary CO ₂ cylinder 51 is measured by weight with the first weigh scale 54.

<First Recycled CO ₂ Cylinder 52 → Second Recycled CO ₂ Cylinder 53>
Next, when the remaining amount of CO ₂ in the replenishment CO ₂ cylinder 51 reaches the first weight%, the CO ₂ path is switched as follows. The first weight% is a weight% in which the remaining amount of CO ₂ in the replenishing CO ₂ cylinder 51 becomes small and CO ₂ cannot be supplied to the vacuum chamber 27a at a constant pressure, and preferably 5% by weight to 20% by weight. % Range (for example, 10% by weight).

The fourth control unit opens the first and third valves of the fourth three-way valve of the fourth switching mechanism of the switching unit 59 and closes the second valve. The first control unit 60 opens the second valve 63 and the third valve 62 of the first three-way valve 57 and closes the first valve 64. The third control unit opens the first and second valves of the third three-way valve of the third switching mechanism of the switching unit 59 and closes the third valve. This closes the first path for supplying CO ₂ from the replenishing CO ₂ cylinder 51 to the vacuum chamber 27a, and the second path for supplying CO ₂ from the switching unit 59 to the vacuum chamber 27a and the first recycled CO ₂ cylinder. The fifth path for supplying CO ₂ from 52 to the first three-way valve 57 is opened, and the seventh path for supplying CO ₂ from the second three-way valve 58 to the first recycled CO ₂ cylinder 52 is closed. The eighth path for supplying CO ₂ from the second three-way valve 58 to the second recycle CO ₂ cylinder 53 is opened. That is, the first switching mechanism switches from the first path to the second path, the third switching mechanism opens the fifth path, and the fourth switching mechanism switches from the seventh path to the eighth path. .

By the above switching, CO ₂ is supplied from the first recycled CO ₂ cylinder 52 into the vacuum chamber 27a, and the object to be cleaned in the vacuum chamber 27a is cleaned by this CO ₂ . This cleaning method for the object to be cleaned will be described in a second embodiment to be described later. The CO ₂ in the vacuum chamber 27a is discharged by the vacuum pump 23a, and the discharged CO ₂ is sent to the particle filter 71. In the discharge discharged by the vacuum pump 23a, particles such as inorganic contamination are contained in addition to CO ₂ . These particles are removed by the particle filter 71. Then, the discharge discharged by the vacuum pump 23 a is sent to the organic matter removal filter 72. The emission contains organic substances in addition to CO ₂ . This organic matter is removed by the organic matter removing filter 72. The CO ₂ from which particles and organic substances have been removed is pressurized and liquefied by a CO ₂ liquefaction pressure pump 73, the liquefied CO ₂ is cooled by a cooler 74, and the cooled liquefied CO ₂ is compressed by a compressor 75. And is collected and stored in the second recycle CO ₂ cylinder 53 through the switching unit 59.

After feeding CO ₂ into the vacuum chamber 27a from the first recycle CO ₂ cylinder 52 as described above, washing the object to be cleaned in the vacuum chamber 27a by the CO _2, the vacuum pump of CO ₂ in the vacuum chamber 27a The exhausted CO ₂ is liquefied, and the liquefied CO ₂ is collected in the second recycle CO ₂ cylinder 53. In this way, CO ₂ once used can be recycled. Since the liquefied CO ₂ is vaporized in the vacuum chamber 27a and then CO ₂ is liquefied and recovered again, it can be purified and recovered with high purity CO ₂ .

<Second Recycled CO ₂ Cylinder 53 → First Recycled CO ₂ Cylinder 52>
While the liquefied CO ₂ is being collected in the second recycled CO ₂ cylinder 53 as described above, the remaining amount of CO ₂ in the first recycled CO ₂ cylinder 52 is measured by weight by the second weigh scale 55. ing. Then, when the remaining amount of CO ₂ in the first recycled CO ₂ cylinder 52 becomes the second weight%, the CO ₂ route is switched as follows. The second weight% is the weight% in which the remaining amount of CO ₂ in the first recycled CO ₂ cylinder 52 becomes small and CO ₂ cannot be supplied to the vacuum chamber 27a at a constant pressure, and preferably 5% by weight. % To 20% by weight (for example, 10% by weight). Further, since the recovery rate of the first recycled CO ₂ cylinder 52 is not 100%, the second weigh scale 55 does not show 100% by weight when the supply from the first recycled CO ₂ cylinder 52 to the vacuum chamber 27a is started. .

The fourth control unit opens the first and second valves of the fourth three-way valve of the fourth switching mechanism of the switching unit 59 and closes the third valve. The third control unit opens the second valve and the third valve of the third three-way valve of the third switching mechanism of the switching unit 59 and closes the first valve. As a result, the fifth path for supplying CO ₂ from the first recycled CO ₂ cylinder 52 to the first three-way valve 57 is closed, and CO is supplied from the _second recycled CO ₂ cylinder 53 to the first three-way valve 57. The sixth path for supplying ₂ is opened, the eighth path for supplying CO ₂ from the second three-way valve 58 to the second recycled CO ₂ cylinder 52 is closed, and the second three-way valve 58 opens the second path. A seventh path for supplying CO ₂ to one recycled CO ₂ cylinder 52 is opened. That is, the third switching mechanism switches from the fifth path to the sixth path, and the fourth switching mechanism switches from the eighth path to the seventh path.

By the above switching, CO ₂ is supplied from the second recycle CO ₂ cylinder 53 into the vacuum chamber 27a, and the object to be cleaned in the vacuum chamber 27a is cleaned by this CO ₂ . This cleaning method for the object to be cleaned will be described in a second embodiment to be described later. The CO ₂ in the vacuum chamber 27a is discharged by the vacuum pump 23a, and the discharged CO ₂ is sent to the particle filter 71. In the discharge discharged by the vacuum pump 23a, particles such as inorganic contamination are contained in addition to CO ₂ . These particles are removed by the particle filter 71. Then, the discharge discharged by the vacuum pump 23 a is sent to the organic matter removal filter 72. The emission contains organic substances in addition to CO ₂ . This organic matter is removed by the organic matter removing filter 72. The CO ₂ from which particles and organic substances have been removed is pressurized and liquefied by a CO ₂ liquefaction pressure pump 73, the liquefied CO ₂ is cooled by a cooler 74, and the cooled liquefied CO ₂ is compressed by a compressor 75. And is collected and stored in the first recycle CO ₂ cylinder 52 through the switching unit 59.

After feeding CO ₂ into the vacuum chamber 27a from the second recycle CO ₂ cylinder 53 as described above, washing the object to be cleaned in the vacuum chamber 27a by the CO _2, the vacuum pump of CO ₂ in the vacuum chamber 27a The exhausted CO ₂ is liquefied, and the liquefied CO ₂ is collected in the first recycle CO ₂ cylinder 52. In this way, the CO ₂ used twice can be recycled. Since the liquefied CO ₂ is vaporized in the vacuum chamber 27a and then CO ₂ is liquefied and recovered again, it can be purified and recovered with high purity CO ₂ .

While the liquefied CO ₂ is being collected in the first recycled CO ₂ cylinder 52 as described above, the remaining amount of CO ₂ in the _second recycled CO ₂ cylinder 53 is measured by weight by the third weighing scale 56. ing. When the remaining amount of CO ₂ in the _second recycled CO ₂ cylinder 53 reaches 3% by weight, CO ₂ is supplied from the first recycled CO ₂ cylinder 52 as described above into the vacuum chamber 27a, The path is switched to the path for collecting the CO ₂ in the vacuum chamber 27 a to the second recycle CO ₂ cylinder 53. Note that the third weight% is a weight% in which the remaining amount of CO ₂ in the _second recycled CO ₂ cylinder 53 is reduced and CO ₂ cannot be supplied into the vacuum chamber 27a at a constant pressure, and preferably 5% by weight. % To 20% by weight (for example, 10% by weight). Since the recovery rate of the second recycled CO ₂ cylinder 53 is not 100%, the third weighing scale 56 does not show 100% by weight when the second recycled CO ₂ cylinder 53 starts to be supplied to the vacuum chamber 27a. .

The step of supplying CO ₂ from the first recycled CO ₂ cylinder 52 into the vacuum chamber 27a and collecting it into the second recycled CO ₂ cylinder 53, and the second recycled CO ₂ cylinder 53 into the vacuum chamber 27a. supplying CO _2, repeat the step of recovering the first recycle CO ₂ cylinder 52. Since the recovery rate is not 100%, by repeating this several times, after there is no available CO ₂ , the replenishment CO ₂ cylinder 51 is replaced, and the new replenishment CO ₂ cylinder 51 replaces the vacuum chamber 27a. The process of supplying CO ₂ is repeated. As a result, the amount of CO ₂ used can be drastically reduced.

In the present embodiment, the CO ₂ remaining amounts of the supplementary CO ₂ cylinder 51, the first recycled CO ₂ cylinder 52, and the second recycled CO ₂ cylinder 53 are 1% by weight, 2% by weight, and 3% by weight, respectively. At this time, the CO ₂ path is switched, but the CO ₂ remaining amount of each of the supplementary CO ₂ cylinder 51, the first recycled CO ₂ cylinder 52, and the second recycled CO ₂ cylinder 53 is changed to the first pressure gauge. 68, the second pressure gauge 69, and the third pressure gauge 70 may be used to measure the CO ₂ path as described above when the first pressure, the second pressure, and the third pressure are reached. However, since the value of the pressure varies depending on the temperature or the like, management by weight is easier than management by pressure.

The first pressure is a pressure at which the remaining amount of CO ₂ in the replenishing CO ₂ cylinder 51 becomes small, and CO ₂ cannot be supplied to the vacuum chamber 27a at a constant pressure, and the cylinder is fully filled. The pressure value is preferably in the range of 5% to 20% (for example, 10%) with respect to the case pressure of 100%.
The second pressure is a pressure at which the remaining amount of CO ₂ in the first recycle CO ₂ cylinder 52 becomes small and CO ₂ cannot be supplied to the vacuum chamber 27a at a constant pressure, and the cylinder is fully filled. When the pressure is 100%, the pressure value is preferably in the range of 5% to 20% (for example, 10%).
The third pressure is a pressure at which the remaining amount of CO ₂ in the _second recycle CO ₂ cylinder 53 is reduced and CO ₂ cannot be supplied to the vacuum chamber 27a at a constant pressure, and the cylinder is fully filled. When the pressure is 100%, the pressure value is preferably in the range of 5% to 20% (for example, 10%).

[Second Embodiment]
In the present embodiment, a method or the like for cleaning the cleaning object by the CO ₂ in a vacuum chamber 27a in FIG. Therefore, the first embodiment can be implemented by appropriately combining the second embodiment.

As shown in FIGS. 2 and 3, the vacuum cleaning apparatus 10 has a vacuum chamber 27a which is a container for evacuating the inside, and a holding mechanism for holding the substrate 12 is disposed in the vacuum chamber 27a. ing. A nozzle 11 for ejecting CO ₂ particles to the substrate 12 is disposed in the vacuum chamber 27a. The vacuum cleaning apparatus 10 has a CO ₂ supply mechanism that supplies pressurized liquefied carbon dioxide (liquefied CO ₂ ) to the nozzle 11, and a vacuum exhaust mechanism that evacuates the vacuum chamber 27a.

The nozzle 11 may be a Venturi tube or a Laval nozzle. In this specification, the Venturi tube is a tube that applies the Venturi effect, and the Venturi effect is an effect of increasing the flow velocity by restricting the flow of fluid, and the Laval nozzle is in the middle of the path through which the fluid passes. This is a nozzle having a narrowed pipe and a path having a shape like an hourglass, which is capable of accelerating fluid by passing through it and obtaining a supersonic speed. The Venturi pipe includes a Laval nozzle.

The CO ₂ supply mechanism has a cylinder 14 containing a liquefied carbon dioxide gas (liquefied CO ₂ ) 13 pressurized to 6 MPa, and this cylinder 14 is connected to one end of a valve 16 by a pipe 15. The pipe 15 may have a siphon pipe. The other end of the valve 16 is connected to one end of the nozzle 11. By opening the valve 16, pressurized liquefied CO ₂ 13 in the cylinder 14 is supplied to the nozzle 11 through the pipe 15 and the valve 16, and CO ₂ particles are ejected from the other end of the nozzle 11.

The holding mechanism includes a holding unit 17 that holds the substrate 12 and a vacuum pump (not shown) connected to the holding unit 17. The substrate 12 is vacuum-sucked and held on the holding part 17 by evacuating with a vacuum pump. An angle θ ₁ formed by a surface (back surface) 12 a opposite to the cleaning surface of the substrate 12 held by the holding unit 17 and the horizontal surface 20 is 90 °. In addition, a heater 19 for heating the substrate 12 is disposed in the holding unit 17. The holding mechanism has a rotation mechanism (not shown) that rotates the holding unit 17. In the present embodiment, the substrate 12 is held by the holding unit 17 by vacuum suction, but is not limited to this, and the substrate 12 is held by the holding unit 17 by electrostatic chucking or a mechanical holding mechanism. It may be held.

The vacuum cleaning apparatus 10 has a moving mechanism 50 that moves the nozzle 11, and the moving mechanism 50 changes the relative position between the nozzle 11 and the substrate 12 held by the holding mechanism. The moving mechanism 50 can use, for example, an XY table. In this embodiment, the moving mechanism 50 that moves the nozzle 11 is used to change the relative position between the nozzle 11 and the substrate 12 held by the holding mechanism. However, the nozzle 11 that is moved using the moving mechanism that moves the holding mechanism. And the relative position of the substrate 12 held by the holding mechanism may be changed.

In the present embodiment, the cleaning surface of the substrate 12 is the angle theta ₁ made of the surface 12a and the horizontal plane 20 of the opposite side is set to 90 °, it is not limited thereto, the angle theta ₁ 45 ° Any angle within the range of ˜180 ° is acceptable.

The angle θ ₂ formed by the direction 21 in which the CO ₂ particles are ejected from the nozzle 11 and the cleaning surface (surface) 12b of the substrate 12 is preferably in the range of 20 ° to 90 °.

The vacuum exhaust mechanism has an exhaust port 22a disposed below the substrate 12, and the exhaust port 22a is disposed below the substrate 12 held by the holding mechanism. The exhaust hole 22a has a slit shape, and the length in the longitudinal direction of the slit shape is preferably equal to or larger than the outer diameter of the substrate 12 (see FIG. 3). As a result, particles generated when the substrate 12 is cleaned can be easily exhausted from the exhaust port 22a. In the present specification, “downward” means the direction of gravity.

An exhaust path 22 is connected to the exhaust port 22a, and a filter 42a is connected to the exhaust path 22. The filter 42a is preferably a metal filter. Particles and the like during cleaning can be captured by the filter 42a. The filter 42a is connected to a stop valve 43a, and the stop valve 43a is connected to the pressure control valve 41. The pressure control valve 41 is connected to a vacuum pump 23a as an exhaust means. The pressure of the exhaust by the vacuum pump 23a can be controlled by the pressure control valve 41.

Next, a method for cleaning a substrate using the cleaning apparatus shown in FIG. 2 will be described.
First, the substrate 12 is held on the holding unit 17 by vacuum suction. Then, the position of the substrate 12 is set so that the angle θ _{1 formed} by the surface opposite to the surface (cleaning surface) of the substrate 12 and the horizontal surface is within a range of 45 ° to 180 ° (preferably 70 ° to 110 °). Adjust. In FIG. 2, θ ₁ is 90 °.

Next, the inside of the vacuum chamber 27a is evacuated by the evacuation mechanism. More specifically, the stop valve 43a is opened, and the vacuum chamber 27a is evacuated while the pressure of the vacuum pump 23a is controlled by the pressure control valve 41. The ultimate vacuum in the vacuum chamber 27a at this time is preferably less than 1 Torr, more preferably 5 × 10 ⁻³ Torr or less. By evacuating in this way, almost all the water in the vacuum chamber 27a can be removed, and the dew point in the vacuum chamber 27a is −40 ° C. or lower (preferably −75 ° C. or lower, more preferably −100 ° C. or lower). Can be. In order to set the dew point to −100 ° C. or lower, the degree of vacuum in the vacuum chamber 27a is preferably set to 1 × 10 ⁻⁵ Torr or lower.

Next, the pressurized liquefied CO ₂ 13 in the cylinder 14 is supplied to the nozzle 11 through the pipe 15 and the valve 16 by opening the valve 16. The liquefied CO ₂ 13 accelerated by the venturi effect of the nozzle 11 becomes CO ₂ particles by adiabatic expansion, and the CO ₂ particles are ejected from the nozzle 11 in a direction 21 oblique to the surface 12 b of the substrate 12. The ejected CO ₂ particles are sprayed on the surface 12b of the substrate 12 while being scanned as indicated by an arrow 26 shown in FIG. 3 to clean the entire surface of the substrate 12. At this time, particles or the like on the surface of the substrate 12 are blown off by the CO ₂ particles blown onto the surface of the substrate 12, and the blown-off particles or the like use the gravity and the exhaust port 22 a below the substrate 12 and the exhaust path. 22 and captured by the filter 42a. The gas after removing particles and the like is exhausted by the vacuum pump 23a through the stop valve 43a and the pressure control valve 41.

The pressure in the vacuum chamber 27a during the cleaning of the surface of the substrate 12 may be less than 1 Torr, or may be 1 Torr or more and less than 1 atmosphere. The reason is that in the process of evacuating the vacuum chamber 27a before cleaning the substrate 12, the dew point in the vacuum chamber 27a is lowered to −40 ° C. or lower, and the substrate 12 is subsequently cleaned with CO ₂ particles. This is because the dew point in the vacuum chamber 27a is considered not to rise.

Thereafter, the holding unit 17 is rotated by 45 ° or 90 ° as indicated by the arrow 25 by the rotation mechanism, whereby the substrate 12 held by the holding unit 17 is rotated by 45 ° or 90 °.

Next, the entire surface of the substrate 12 is cleaned by spraying CO ₂ particles while scanning the surface 12 b of the substrate 12 by the same method as described above.

Thereafter, by repeatedly rotating the substrate 12 held by the holding unit 17 by 45 ° or 90 ° by the same method as described above and cleaning the entire surface of the substrate 12 by the same method as described above, the substrate 12 is repeated. Complete the surface cleaning.

According to this embodiment, the dew point in the vacuum chamber 27a can be reduced to −40 ° C. or lower by evacuating the vacuum chamber 27a before cleaning the substrate 12. For this reason, the substrate 12 can be cleaned with CO ₂ particles in an atmosphere having a very low dew point. Therefore, it becomes possible to clean a substrate to be cleaned (for example, a glass substrate for organic EL) that is very weak against water.

In the present embodiment, since the vacuum chamber 27a is evacuated to create a clean cleaning atmosphere in the vacuum chamber 27a, a material that easily adsorbs moisture, such as paper, is used as in the prior art. There is no need to use a hepa filter. Therefore, the dew point at the time of cleaning can be further reduced as compared with the conventional cleaning device.

In this embodiment, since the substrate 12 is cleaned in the vacuum chamber 27a, there are almost no generation sources of particles or the like. Therefore, the cleaning effect can be improved as compared with the conventional cleaning apparatus.

In addition, according to the present embodiment, the position of the substrate 12 when the CO ₂ particles ejected from the nozzle 11 are blown onto the substrate 12 is determined by the surface opposite to the surface (cleaning surface) of the substrate 12 and the horizontal plane. The angle θ ₁ to be created is in the range of 45 ° to 180 °, and the blown-off particles on the surface of the substrate 12 are exhausted from below the substrate 12 using gravity. For this reason, it can control that particles etc. adhere again to substrate 12.

In this embodiment, since the inside of the chamber at the time of cleaning is vacuum, the speed of the CO ₂ particles ejected from the nozzle 11 is increased as compared with the case where the inside of the chamber is atmospheric pressure. The velocity of the CO ₂ particles increases if the pressure difference between the orifice in the nozzle and the nozzle is large, and decreases if the pressure difference is small. However, when the chamber is evacuated, the pressure inside the nozzle decreases, and the CO ₂ particles decrease accordingly. Speed increases. Thereby, the cleaning effect of the CO ₂ particles can be enhanced.

[Third Embodiment]
FIG. 4 is a schematic diagram illustrating a cleaning apparatus with CO ₂ recycling according to an aspect of the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and only different parts will be described.

The cleaning apparatus with CO ₂ recycling in FIG. 1 has a vacuum chamber 27a and a vacuum pump 23a, and the object to be cleaned is cleaned by CO ₂ supplied into the vacuum chamber 27a, whereas the CO ₂ recycling in FIG. The attached cleaning apparatus has a chamber 27b, an exhaust fan as an exhaust mechanism, and a nitrogen and CO ₂ separation mechanism (not shown), and the object to be cleaned is cleaned by CO ₂ supplied into the chamber 27b in an atmospheric pressure nitrogen atmosphere. Is different.

The chamber 27b is connected to an exhaust fan 23b as a discharge mechanism by piping, and the exhaust fan 23b exhausts the inside of the chamber 27b. The exhaust fan 23b is connected to a separation mechanism. The separation mechanism separates nitrogen and CO ₂ and supplies the CO ₂ to the third valve 65 of the second three-way valve 58 of the second switching mechanism. It has become.

In this embodiment, the same effect as that of the first embodiment can be obtained.

[Fourth Embodiment]
In the present embodiment, a method of cleaning an object to be cleaned with CO ₂ in the chamber 27b of FIG. 4 will be described. Therefore, the fourth embodiment can be implemented by appropriately combining the third embodiment with the fourth embodiment.

As shown in FIGS. 5 and 6, the cleaning device includes a nozzle 11, a CO ₂ supply mechanism that supplies liquefied carbon dioxide (liquefied CO ₂ ) pressurized to the nozzle 11, a holding mechanism that holds the substrate 12, An exhaust mechanism is provided below the substrate 12.

The holding mechanism includes a holding unit 17 that holds the substrate 12 and a vacuum pump 18 connected to the holding unit 17. By vacuuming with a vacuum pump 18, the substrate 12 is vacuum-sucked and held on the holding part 17. An angle θ ₁ formed by a surface (back surface) 12 a opposite to the cleaning surface of the substrate 12 held by the holding unit 17 and the horizontal surface 20 is 90 °. In addition, a heater 19 for heating the substrate 12 is disposed in the holding unit 17.

The exhaust mechanism includes an exhaust port 22 a disposed below the substrate 12, an exhaust path 22 connected to the exhaust port 22 a, and an exhaust unit (for example, an exhaust pump) 23 b connected to the exhaust path 22. . The exhaust path 22 has a path extending below the exhaust port 22a. In the present specification, “downward” means the direction of gravity.

Further, a pressure control valve 41 is arranged in the exhaust path 22 so that the pressure of the exhaust gas by the exhaust means 23b can be controlled by the pressure control valve 41. Further, a hepa filter 42b is disposed in the exhaust path 22, and particles and the like in the exhaust are captured by the hepa filter 42b, and the gas after removing the particles and the like is discharged to the outside of the chamber 27b. .

As shown in FIGS. 7A and 7B, the nozzle 11 includes a nozzle body 37, a first gasket 36, a second gasket 35, a plunger 34, a first nut 33, a gland 32, and a second gasket. It has a nut 31. Specifically, a first gasket 36, a second gasket 35, and a plunger 34 are connected to the base end side of the nozzle body 37 in this order, and the tip of the gland 32 is connected to the plunger 34. The nozzle body 37, the first gasket 36, the second gasket 35, the plunger 34, and the gland 32 are fixed by a first nut 33. A second nut 31 is attached to the base end of the gland 32. A path for passing liquefied CO ₂ 13 is provided inside the nozzle 11 having such a structure.

A hard film having a Vickers hardness of Hv 1000 to 5000 is formed on the inner wall of the nozzle 11 (the surface constituting the path for passing liquefied CO ₂ 13). This hard film includes DLC (Diamond Like Carbon), TiN, TiCrN, CrN, TiCNi, TiAlN, Al ₂ O ₃ , AlCrN, ZrO ₂ , SiC, Cr, NiP, WC, SiO ₂ , Ta ₂ O ₅ , SiN, And a film containing one selected from the group of SiaAlbOcNd (sialon), in this embodiment, a DLC film having a hydrogen content of 30 atomic% or less is used as the hard film. By setting the hydrogen content to 30 atomic% or less, the DLC film can be made hard. The DLC film preferably has a Vickers hardness of Hv 1200 to 3500.

The DLC film is formed on the inner wall of the nozzle 11 by a plasma CVD method using a high frequency output with a frequency of 10 kHz to 1 MHz (preferably 50 kHz to 800 kHz, more preferably 50 kHz to 500 kHz). Thus, a hard DLC film can be formed by using a frequency of 10 kHz to 1 MHz.

As shown in FIG. 5, the nozzle 11, the substrate 12, the holding mechanism, and the exhaust path 22 are arranged in a chamber 27b. Further, the cleaning device has an introduction mechanism for introducing dry air 44 or nitrogen gas into the chamber 27b, and a relief valve 43b is arranged in the chamber 27b. When the substrate 12 is cleaned, the introduction mechanism introduces dry air 44 or nitrogen gas into the chamber 27b, and the relief valve 43b discharges the dry air or nitrogen gas to the outside of the chamber 27b. In an atmosphere of (−70 ° C. to −100 ° C.), the dew point is controlled to about −20 ° C. The reason for making such an atmosphere is that the CO ₂ particles used for cleaning the substrate 12 are at a temperature of about −73 ° C., so that when the CO ₂ particles are blown onto the substrate 12, the substrate 12 is cooled, This is because water droplets are easily attached, so that no water droplets are attached to the substrate 12. Further, when the substrate 12 is cleaned, the substrate 12 is heated by the heater 19 to prevent water droplets from being attached to the substrate 12.

Next, a method for cleaning a substrate using the cleaning apparatus shown in FIG. 5 will be described.
First, the substrate 12 is placed on the holding unit 17 and evacuated by the vacuum pump 18 to hold the substrate 12 on the holding unit 17 by vacuum suction. Then, the position of the substrate 12 is set so that the angle θ _{1 formed} by the surface opposite to the surface (cleaning surface) of the substrate 12 and the horizontal surface is within a range of 45 ° to 180 ° (preferably 70 ° to 110 °). Adjust. In FIG. 5, θ ₁ is 90 °.

Next, by introducing dry air 44 or nitrogen gas into the chamber 27b, the inside of the chamber 27b is controlled to about −20 ° C. in a dry air or nitrogen atmosphere (−70 ° C. to −100 ° C.).

Next, the pressurized liquefied CO ₂ 13 in the cylinder 14 is supplied to the nozzle 11 through the pipe 15 and the valve 16 by opening the valve 16. Then, the liquefied CO ₂ 13 that has flowed into the gland 32 is compressed inside the plunger 34 whose cross section becomes narrower as it flows toward the tip side, and the Venturi effect that increases the flow velocity at the orifice (most detailed) of the tip of the plunger 34. Is accelerated by. The accelerated liquefied CO ₂ 13 is adiabatically expanded by first and

second gaskets

36, 35 having a divergent cross section into CO ₂ particles, and the CO ₂ particles are rectified by the nozzle body 37. The rectified CO ₂ particles are ejected from the nozzle body 37 in a direction 21 oblique to the surface 12 b of the substrate 12. The ejected CO ₂ particles are sprayed while scanning the surface 12b of the substrate 12 as indicated by an arrow 26 shown in FIG. 6 to clean the entire surface of the substrate 12. At this time, particles and the like on the surface of the substrate 12 are blown off by the CO ₂ particles blown onto the surface of the substrate 12, and the blown particles and the like use the gravity as indicated by an arrow 24 while the exhaust port 22 a and the exhaust path. 22, Exhaust means 23b exhausts the chamber 27b through the pressure control valve 41 and hepa filter 42b.

Thereafter, the holding unit 17 is rotated by 45 ° or 90 ° as indicated by an arrow 25, whereby the substrate 12 held by the holding unit 17 is rotated by 45 ° or 90 °.

Next, the entire surface of the substrate 12 is cleaned by spraying CO ₂ particles while scanning the surface 12 b of the substrate 12 by the same method as described above. At this time, the blown-off particles on the surface of the substrate 12 are exhausted by the exhaust means 23b through the exhaust port 22a, the exhaust path 22, the pressure control valve 41, and the hepa filter 42b as indicated by the arrow 24.

According to the present embodiment, since a hard film having a Vickers hardness of Hv 1000 to 5000 is formed on the inner wall of the nozzle 11, when liquefied CO ₂ passes through the nozzle 11, CO ₂ particles collide with the inner wall of the path of the nozzle 11. Even so, it is possible to prevent the inner wall of the route from being cut. Therefore, even when the substrate was washed 12 with CO ₂ particles can be suppressed surface of the substrate 12 after cleaning is contaminated by metal. Further, the life of the nozzle 11 can be extended.

In addition, according to the present embodiment, the position of the substrate 12 when the CO ₂ particles ejected from the nozzle are blown onto the substrate 12 is formed by the surface opposite to the surface (cleaning surface) of the substrate 12 and the horizontal surface. angle theta ₁ is in the range of 45 ° ~ 180 °, the particles or the like on the surface of the substrate 12 blown exhausting from below the substrate 12 as shown by the arrow 24 gravity while using. For this reason, it can control that particles etc. adhere again to substrate 12.

In other words, to place the substrate 12 at a position angle theta ₁ is in the range of 45 ° ~ 180 ° are arranged, and the exhaust path 22 and exhaust unit 23b below the substrate 12, when evacuating the particles or the like, Exhaust force can be exhausted using not only the exhaust force of the exhaust means 23b but also gravity. As a result, after particles or the like on the substrate 12 are blown off by the CO ₂ particles, the particles or the like can be prevented from reattaching to the surface of the substrate 12. Therefore, it is possible to suppress a reduction in cleaning effect due to reattachment of particles or the like.

Further, according to the present embodiment, since the exhaust path 22 of the exhaust mechanism has a path extending below the exhaust port 22a, the particles are reattached to the surface of the substrate 12 when the particles are exhausted. Can be suppressed.

In addition, according to the present embodiment, when the substrate 12 is cleaned by blowing the CO ₂ particles ejected from the nozzle onto the substrate 12, the particles blown off from the substrate 12 are removed from the exhaust port 22a, the exhaust path 22, The gas is exhausted to the outside of the chamber 27b by the exhaust means 23b through the pressure control valve 41 and the hepa filter 42b. For this reason, it can suppress that the fine particle etc. which cannot be captured with a hepa filter like a prior art reattach on a board | substrate. As a result, a reduction in the cleaning effect on the surface of the substrate can be suppressed.

Note that the first to fourth embodiments described above may be combined with each other.

DESCRIPTION OF SYMBOLS 10 Vacuum type cleaning apparatus 11 Nozzle 12 Board | substrate 12a The surface (back surface) on the opposite side to the cleaning surface (front surface) of a substrate
12b Substrate cleaning surface (surface)
13 Liquefied carbon dioxide (liquefied CO ₂ )
14 cylinder 15 piping 16 valve 17 holding part 18 vacuum pump 19 heater 20 horizontal surface 21 direction in which CO ₂ particles are ejected from the nozzle 22 exhaust path

22a exhaust port

23a vacuum pump 23b exhaust means 24, 25, 26 arrow 27a vacuum chamber 27b chamber 31 Second nut 32 Gland 33 First nut 34 Plunger 35 Second gasket 36 First gasket 37 Nozzle body 41 Pressure control valve 42a Filter

42b Hepa filter

43a Stop valve

43b Relief valve 44 Dry air 51 Supplementary CO ₂ cylinders (first liquefied CO ₂ cylinder)
52 First recycled CO ₂ cylinder (second liquefied CO ₂ cylinder)
53 Second recycled CO ₂ cylinder (third liquefied CO ₂ cylinder)
54 First weighing scale (load cell)
55 Second weighing scale (load cell)
56 Third weighing scale (load cell)
57 first three-way valve 58 second three-way valve 59 switching unit 60 first control unit 61 second control unit 62 third valve of the first three-way valve 63 second of the first three-way valve Valve 64 First valve of the first three-way valve 65 Third valve of the second three-way valve 66 First valve of the second three-way valve 67 Second valve of the second three-way valve 68 First pressure Meter (pressure gauge)
69 Second pressure gauge (pressure gauge)
70 Third pressure gauge (pressure gauge)
71 Particle filter 72 Organic substance removal filter 73 CO ₂ liquefaction pressure pump 74 Cooler 75 Compressor 76 Exhaust port 77 Valve 101 Nozzle 102 Substrate 103 CO ₂ particle 104 Duct 104a Inlet port

Claims

A chamber;
A first liquefied CO 2 cylinder for supplying CO 2 into the chamber;
A discharge mechanism for discharging the CO 2 in the chamber;
A liquefaction mechanism for liquefying the CO 2 discharged by the discharge mechanism;
A second liquefied CO 2 cylinder containing CO 2 liquefied by the liquefaction mechanism;
Comprising
The CO 2 contained in the second liquefied CO 2 cylinder is supplied into the chamber,
A cleaning apparatus with CO 2 recycling, wherein an object to be cleaned is cleaned by CO 2 supplied into the chamber from the first liquefied CO 2 cylinder or the second liquefied CO 2 cylinder.
In claim 1,
It said second liquefied CO CO 2 contained in the 2 cylinder is supplied to the chamber, the CO 2 in the chamber is discharged by the discharge mechanism, are liquefied by that discharged the CO 2 is the liquefaction mechanism the third liquefied CO 2 cylinder for containing the liquefied CO 2 further comprising,
The third liquefied CO CO 2 contained in the 2 cylinder is supplied to the chamber, the CO 2 in the chamber is discharged by the discharge mechanism, are liquefied by that discharged the CO 2 is the liquefaction mechanism The liquefied CO 2 is accommodated in the second liquefied CO 2 cylinder,
A cleaning apparatus with CO 2 recycling, wherein the object to be cleaned is cleaned with CO 2 supplied from the third liquefied CO 2 cylinder into the chamber.
A chamber;
A second liquefied CO 2 cylinder for supplying CO 2 into the chamber;
A discharge mechanism for discharging the CO 2 in the chamber;
A liquefaction mechanism for liquefying the CO 2 discharged by the discharge mechanism;
A third liquefied CO 2 cylinder containing CO 2 liquefied by the liquefaction mechanism;
Comprising
The third liquefied CO CO 2 contained in the 2 cylinder is supplied to the chamber, the CO 2 in the chamber is discharged by the discharge mechanism, are liquefied by that discharged the CO 2 is the liquefaction mechanism , the liquefied CO 2 is accommodated in the second liquefied CO 2 cylinder,
A cleaning apparatus with CO 2 recycling, wherein an object to be cleaned is cleaned by CO 2 supplied into the chamber from the second liquefied CO 2 cylinder or the third liquefied CO 2 cylinder.
In any one of Claims 1 thru | or 3,
The exhaust mechanism has a vacuum pump for evacuating the chamber,
It said second liquefied CO 2 cylinder, the discharged from the vacuum pump, cleaning apparatus CO 2 with recycling, characterized in that it is intended to accommodate the CO 2 that is liquefied by the liquefaction mechanism.
In any one of Claims 1 thru | or 3,
The exhaust mechanism has an exhaust fan for exhausting the chamber.
Said second liquefied CO 2 cylinder, the exhaust fan is discharged from, CO 2 cleaning apparatus with recycling, characterized in that it is intended to accommodate the CO 2 that is liquefied by the liquefaction mechanism.
In claim 4,
The vacuum pump, CO 2 cleaning apparatus with recycling, characterized in that it comprises a dry pump or a mechanical booster pump.
In claim 1 or 2,
A first path for supplying the CO 2 from the first liquefied CO 2 cylinder into the chamber, the switching between the second path for supplying the CO 2 into the chamber from said second liquefied CO 2 cylinder A cleaning apparatus with CO 2 recycling, comprising a switching mechanism of 1.
In any one of Claims 1, 2, and 7,
A second switching mechanism disposed between the discharge mechanism and the second liquefied CO 2 cylinder;
The second switching mechanism switches a third path for supplying the CO 2 from the chamber to the second liquefied CO 2 cylinder and a fourth path for exhausting the CO 2 from the chamber to the exhaust port. A cleaning apparatus with CO 2 recycling, characterized in that
In claim 2 or 3,
The switch between the the fifth path for supplying the CO 2 from the second liquefied CO 2 cylinder into the chamber, the third liquefied CO for supplying the CO 2 from 2 bomb into the chamber sixth path A cleaning apparatus with CO 2 recycling, characterized in that it has 3 switching mechanisms.
In any one of claims 2, 3 and 9,
A fourth path is switched between a seventh path for supplying the CO 2 from the chamber to the second liquefied CO 2 cylinder and an eighth path for supplying the CO 2 from the chamber to the third liquefied CO 2 cylinder. A cleaning apparatus with CO 2 recycling, comprising a switching mechanism.
In claim 2,
A first path for supplying the CO 2 from the first liquefied CO 2 cylinder into the chamber, the switching between the second path for supplying the CO 2 into the chamber from said second liquefied CO 2 cylinder 1 switching mechanism;
A second switching mechanism that switches between a third path for supplying the CO 2 from the chamber to the second liquefied CO 2 cylinder and a fourth path for exhausting the CO 2 from the chamber to an exhaust port;
The supply and the second liquefied CO 2 from said cylinder first fifth path for supplying to the switching mechanism of the CO 2, the CO 2 in the first switching mechanism from the third liquefied CO 2 cylinder A third switching mechanism for switching between six routes;
The supply and the second from said switching mechanism of the second liquefied CO supplies the CO 2 to 2 cylinder seventh path, the CO 2 in the third liquefied CO 2 cylinder from said second switching mechanism A fourth switching mechanism for switching between eight routes;
Comprising
The second switching mechanism is disposed between the discharge mechanism and the second liquefied CO 2 cylinder,
The third switching mechanism is disposed between the first switching mechanism and the second liquefied CO 2 cylinder,
The fourth switching mechanism is disposed between the second switching mechanism and the second liquefied CO 2 cylinder, and is a cleaning apparatus with CO 2 recycling.
In claim 7 or 11,
The first switching mechanism includes:
A first three-way valve having a first valve connected to the first liquefied CO 2 cylinder, a second valve connected to the chamber, and a third valve connected to the second liquefied CO 2 cylinder;
A first control unit for controlling the first three-way valve,
The first control unit opens the first valve and the second valve and closes the third valve when supplying the CO 2 into the chamber from the first liquefied CO 2 cylinder. And when the CO 2 is supplied from the second liquefied CO 2 cylinder into the chamber, the second valve and the third valve are opened and the first valve is closed. A cleaning device with CO 2 recycling.
In claim 8 or 11,
The second switching mechanism includes
A second three-way valve having a first valve connected to the exhaust mechanism, a second valve connected to the exhaust port, and a third valve connected to the second liquefied CO 2 cylinder;
A second control unit for controlling the second three-way valve,
The second control unit opens the first valve and the third valve and closes the second valve when supplying the CO 2 into the chamber from the first liquefied CO 2 cylinder. Then, control is performed so that the CO 2 in the chamber discharged by the discharge mechanism is accommodated in the second liquefied CO 2 cylinder, and the first liquefied CO 2 cylinder or the second liquefied CO 2 cylinder is stored. wherein said chamber from when the CO 2 does not supply, the opening of the first valve and the second valve, and the third valve closing control CO 2 cleaning apparatus with recycling, which comprises as.
In any one of claims 7, 8, 11 and 12,
A first weigh scale that measures the remaining amount of CO 2 in the first liquefied CO 2 cylinder by weight;
The first switching mechanism is configured such that when the remaining amount of CO 2 in the first liquefied CO 2 cylinder measured by the first weigh scale becomes the first weight%, the first switching mechanism is configured to perform the first switching from the first path. The cleaning apparatus with CO 2 recycling is controlled to supply the CO 2 into the chamber from the second liquefied CO 2 cylinder by switching to the second path.
In any one of claims 7, 8, 11 and 12,
A first pressure gauge that measures the remaining amount of CO 2 in the first liquefied CO 2 cylinder by pressure;
The first switching mechanism is configured such that when the remaining amount of CO 2 in the first liquefied CO 2 cylinder measured by the first pressure gauge becomes a first pressure, the second switching mechanism is configured to perform the second switching from the first path. The cleaning apparatus with CO 2 recycling is controlled to supply the CO 2 into the chamber from the second liquefied CO 2 cylinder by switching to the path.
In any one of Claims 9 thru | or 11,
A second weigh scale that measures the remaining amount of CO 2 in the second liquefied CO 2 cylinder by weight;
When the remaining amount of CO 2 in the second liquefied CO 2 cylinder measured by the second weigh scale becomes 2% by weight, the third switching mechanism is configured to release the fifth path from the fifth path. The cleaning apparatus with CO 2 recycling is controlled so as to supply the CO 2 from the third liquefied CO 2 cylinder into the chamber by switching to the path of No. 6.
In any one of Claims 9 thru | or 11,
A second pressure gauge for measuring the remaining amount of CO 2 in the second liquefied CO 2 cylinder by pressure;
When the remaining amount of CO 2 in the second liquefied CO 2 cylinder measured by the second pressure gauge becomes the second pressure, the third switching mechanism is configured to perform the sixth switching from the fifth path. The cleaning apparatus with CO 2 recycling is controlled so as to supply the CO 2 into the chamber from the third liquefied CO 2 cylinder by switching to the path.
In any one of Claims 1 thru | or 17,
A cleaning apparatus with CO 2 recycling, comprising: a particle filter that removes particles in the discharge containing CO 2 discharged by the discharge mechanism; and an organic filter that removes organic matter in the discharge.
In the operation method of the cleaning apparatus with CO 2 recycling according to any one of claims 1, 2, 7, 8, and 11 to 15,
Supplying CO 2 into the chamber from said first liquefied CO 2 cylinder, the said CO 2 in the chamber is discharged by the discharge mechanism, liquefying the CO 2 discharged by the discharge mechanism by the liquefaction mechanism And storing the CO 2 liquefied by the liquefaction mechanism in the second liquefied CO 2 cylinder,
Stop from the first liquefied CO 2 cylinder for supplying CO 2 into the chamber, by supplying CO 2 from the second liquefied CO 2 cylinder into the chamber, the CO 2 in the chamber The operation method of the cleaning apparatus with CO 2 recycling, wherein the discharging mechanism discharges the CO 2 recycling mechanism.
In the operation method of the cleaning apparatus with CO 2 recycling according to claim 12,
The cleaning device with CO 2 recycling is:
A second three-way valve having a first valve connected to the exhaust mechanism, a second valve connected to the exhaust port, and a third valve connected to the second liquefied CO 2 cylinder;
A second control unit for controlling the second three-way valve,
The first control unit opens the first valve and the second valve of the first three-way valve and closes the third valve, and the second control unit performs the second three-way valve. open the first valve and the third valve, and the by closing the second valve to supply the CO 2 from the first liquefied CO 2 cylinder into the chamber, the CO 2 in the chamber Discharging by the discharge mechanism, liquefying the CO 2 discharged by the discharge mechanism by the liquefaction mechanism, storing the CO 2 liquefied by the liquefaction mechanism in the second liquefied CO 2 cylinder,
The first control unit opens the second valve and the third valve of the first three-way valve, and closes the first valve, so that the second liquefied CO 2 cylinder enters the chamber. A method of operating a cleaning apparatus with CO 2 recycling, wherein the CO 2 is supplied.