JP2002057137A - Wafer washing device and water treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wafer washing device with which sufficient clean air can be supplied by a downflow, diffusion of a chemical agent atmosphere can be prevented in an appropriately closed structure and reattachment of mist upon drying can be prevented when chemical agent washing and spin drying are performed in a bath. SOLUTION: A downflow is formed in a washing bath 11 by providing a suction port 12 on top thereof and an exhaust port 17 at the bottom thereof. A wafer to be washed Wf is rotated in the washing bath 11 so that the wafer to be washed Wf can be washed and dried in the same washing bath 11. This wafer washing device is equipped with water jetting nozzles 14, 14 for forming a water curtain covering the suction port 12 with a curtain made of water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate cleaning apparatus capable of cleaning a substrate such as a semiconductor wafer with a chemical solution and spin drying in the same cleaning tank and a substrate processing apparatus using the substrate cleaning apparatus. It is.

[0002]

2. Description of the Related Art In a single-wafer cleaning apparatus for cleaning a substrate such as a semiconductor wafer while rotating the substrate, when cleaning is performed using a chemical as a cleaning liquid, the cleaning tank is evacuated in consideration of diffusion of a chemical liquid atmosphere, and the inside of the tank is exhausted. It was necessary to make the washing tank closed (closed structure) in order to make a small negative pressure. When so-called spin drying is performed in which the substrate is rotated at high speed in such a cleaning tank having a closed structure to remove the liquid droplets of the cleaning liquid by centrifugal force and dried, a clean flow is obtained from the top of the cleaning tank by a down flow due to the closed structure. Air could not be sufficiently introduced, the substrate was dried in a chemical solution atmosphere, and it was difficult to wash the substrate due to mist reattachment and the like.

Therefore, in order to eliminate the re-adhesion of the mist and the like, it is necessary to separately provide a cleaning tank for performing chemical cleaning and a drying tank for performing spin drying. However, when the washing tank and the drying tank are separately provided, the size becomes large, the installation space is required widely, and the cost increases.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above points. Even when a chemical solution is washed and spin-dried in a single tank, a sufficient supply of clean air and an appropriate An object of the present invention is to provide a substrate cleaning apparatus having a closed structure capable of preventing diffusion of a chemical solution atmosphere and preventing re-adhesion of mist during drying, and a substrate processing apparatus using the substrate cleaning apparatus.

[0005]

According to a first aspect of the present invention, there is provided a cleaning tank provided with a cleaning tank, an intake port provided at an upper portion of the cleaning tank, and an exhaust port provided at a bottom portion. A substrate cleaning apparatus that forms a down flow inside, rotates a substrate to be cleaned in the cleaning tank, and enables cleaning and drying of the substrate to be cleaned in the same cleaning tank. A water curtain forming means for covering with a water curtain is provided.

A water curtain forming means is provided as described above,
Since the intake port can be covered with a curtain made of water, there is a possibility that a cleaning liquid mist or the like may be scattered from the cleaning tank through the intake port (for example, when the exhaust system is stopped due to a failure or the like, When the internal pressure of the cleaning tank becomes higher than the external pressure for some reason), the water inlet covers the inlet with a curtain of water, so that the chemical mist is absorbed by the water curtain and scatters outside the cleaning tank through the inlet. Never.

[0007] The invention described in claim 2 is the first invention.
In the substrate cleaning apparatus described in the above, the water curtain forming means is provided when the exhaust system to which the exhaust port is connected fails or when the internal pressure P _{IN of the} cleaning tank is equal to or higher than the external pressure P _OUT (P _IN ≧ P
_OUT ), the inlet is covered with a curtain of water.

[0008] The invention described in claim 3 is the first invention.
Alternatively, in the substrate cleaning apparatus described in 2, the baffle plate for preventing the droplets from scattering from the inside of the cleaning tank to the outside is provided at the intake port.

According to a fourth aspect of the present invention, there is provided a load / unload section for loading / unloading a substrate to be processed, a substrate processing section for processing a substrate to be processed, a substrate cleaning section for cleaning and drying the substrate to be processed, and various parts. A substrate transport mechanism for transporting the substrate to the substrate processing mechanism. The substrate transport mechanism takes out an unprocessed substrate from the loading / unloading unit, transports the substrate to the substrate processing unit, and processes the substrate processed by the substrate processing unit. Transported to the substrate cleaning section,
The substrate to be processed, which has been cleaned and dried in the substrate cleaning section, is loaded and
In the substrate processing apparatus that is transported and stored in the unloading section,
The substrate cleaning unit is provided with at least one cleaning device, and at least one of the cleaning devices uses the substrate cleaning device according to any one of claims 1 to 3.

[0010] Since the substrate cleaning section uses the substrate cleaning apparatus according to any one of claims 1 to 3, there is a possibility that a cleaning liquid mist or the like may scatter from inside the cleaning tank of the substrate cleaning apparatus (for example, exhaust gas). If the system stops due to a failure,
When the internal pressure of the cleaning tank becomes higher than the external pressure for some reason), the water inlet covers the inlet with a curtain of water, so that the chemical mist is absorbed by the water curtain and scatters outside the cleaning tank through the inlet. The substrate processing apparatus does not need to be used. Further, when spin drying is performed by the substrate cleaning apparatus in the cleaning section, contamination or the like due to re-adhesion of the chemical mist can be prevented.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a schematic configuration of a substrate cleaning apparatus according to the present invention. In FIG. 1, 11
Denotes a cleaning tank of the substrate cleaning apparatus 10, and an inlet 12 for introducing clean air is provided at the top of the cleaning tank 11. The intake port 12 is provided with a large number of baffle plates 13 each having an inverted “C” cross section so that liquid droplets such as a chemical mist do not scatter from inside the cleaning tank 11.

A pair of water injection nozzles 14 and 14 are provided at the intake port 12 so as to face each other.
Water curtain 15 is formed by spraying water in a plane from 4 and 14, and the entire surface of intake port 12 can be covered with water curtain 15.

Exhaust ports 17, 17 are provided at the bottom of the cleaning tank 11, and the exhaust ports 17, 17 are connected to an exhaust system (not shown). A substrate holding / rotating mechanism 18 that holds and rotates a substrate to be cleaned Wf such as a semiconductor wafer is disposed inside the cleaning tank 11. A plurality of substrate holding / rotating mechanisms 18 (4 in FIG.
) Of the plurality of holding members 19.
Is mounted on a base 20, which is supported by a rotating shaft 21 and is rotatable in the direction of arrow A by a rotary drive mechanism (not shown) arranged outside the washing tank 11. Note that a seal mechanism 22 is provided at a portion where the rotating shaft 21 passes through the bottom of the cleaning tank 11. In addition, 25 is a drain hole.

Chemical solution nozzles 23, 23 for spraying a chemical solution as a cleaning liquid on the upper and lower surfaces of the substrate Wf to be cleaned held by the substrate holding and rotating mechanism 18 are provided in the vertical direction of the substrate Wf to be cleaned. A pure water nozzle 24 for injecting ultrapure water as a cleaning liquid onto the upper and lower surfaces of the substrate Wf to be cleaned;
24 are provided in the up-down direction. Although not shown, the substrate holding and rotating mechanism 18 includes a plurality of holding members 1.
An opening / closing mechanism for opening and closing the cleaning substrate 9 is provided so that the substrate to be cleaned Wf carried in by the transport robot can be held therebetween, and the substrate to be cleaned Wf that has been washed and dried can be carried out by the transport robot.

As shown in FIG. 2, ultrapure water W is supplied to the water injection nozzles 14 and 14 from a pump 16. The drive of the pump 16 is controlled by a control unit 28. The control unit 28 has a pressure P _IN in the cleaning tank 11.
Pressure sensor 26 for detecting the pressure, the pressure P _OUT outside the cleaning tank 11
Output signal from the external pressure sensor 27 for detecting the exhaust gas, and an exhaust system stop signal 2 for notifying that the exhaust system has stopped due to a failure or the like.
9 has been entered.

In the substrate cleaning apparatus having the above structure, the inside of the cleaning tank 11 is evacuated through the exhaust ports 17, 17, and P _IN <P
_When it becomes _OUT , the clean air passes through the suction port 12 and the washing tank 1
1 to form a downflow in the tank and exhaust port 1
It is discharged from 7,17. In this downflow atmosphere, diluted hydrofluoric acid (D
HF) The liquid or the like is sprayed onto the upper and lower surfaces of the rotating substrate Wf held and rotated by the substrate holding / rotating mechanism 18, and the substrate Wf
Is washed with a chemical solution. Subsequently, ultrapure water is jetted from the pure water nozzles 24, 24 onto the upper and lower surfaces of the substrate Wf to be cleaned, and the substrate Wf to be cleaned is jetted.
Is washed with pure water. Subsequently, the substrate to be cleaned Wf is rotated at a high speed by the high-speed rotation of the substrate holding and rotating mechanism 18, and the liquid droplets attached to the surface are removed by the centrifugal force to remove the substrate to be cleaned Wf.
Spin dry.

Through the above chemical cleaning, pure water cleaning and spin drying, a downflow of clean air is formed in the cleaning tank 11 and the air inlet 12 is provided with a baffle plate 13.
The mist of the chemical solution or the pure water is exhausted without scattering to the outside, and the substrate Wf to be cleaned is not contaminated by the re-adhesion of the mist.

When the exhaust system is stopped due to a failure of the exhaust system or the like, and the exhaust system stop signal 29 is input to the control unit 28, or for some reason, the pressure in the cleaning tank 11 becomes higher than the external pressure. In other words, if P _IN ≧ P _{OUT and} the mist of the chemical such as dilute hydrofluoric acid (DHF) is likely to scatter outside the cleaning tank 11 through the inlet 12, the control unit 28 starts the pump 16. Then, ultrapure water is injected from the water injection nozzles 14, 14 to form water curtains 15, 15, and the water curtains 15, 15 cover the air inlet 12. As a result, the mist of the chemical solution or the like that tends to scatter outside through the intake port 12 is absorbed by the water curtains 15 and 15 and does not scatter outside. The water curtains 15, 15 may be formed also at the time of cleaning the substrate Wf to be cleaned with a chemical solution or at the time of cleaning with pure water.

In the above example, the cleaning mechanism of the substrate cleaning apparatus uses the substrate to be cleaned Wf rotated and held by the substrate holding and rotating mechanism.
A cleaning mechanism for jetting and cleaning the chemical solution from the chemical solution nozzles 23 and 23 and the ultrapure water from the pure water nozzles 24 and 24 is shown on the upper and lower surfaces. However, the cleaning mechanism is not limited to this. For example, as shown in FIG. Has a swing arm 111 supported by a swing rotation shaft 110, and a rotation shaft 112 is attached below the tip of the swing arm 111, and the tip of the rotation shaft 112 is made of a porous material such as a sponge material. A configuration in which a pencil-type cleaning tool 113 having a cleaning member 113a is attached may be used.

In this cleaning mechanism, the cleaning member 113a of the cleaning tool 113 is brought into contact with the upper surface of the substrate Wf to be cleaned which is rotated and held by the substrate holding and rotating mechanism 18, and is omitted in FIG. 3, but as shown in FIG. Then, chemical solution cleaning and pure water cleaning are performed while jetting a chemical solution from the chemical solution nozzles 23 and 23 and ultrapure water from the pure water nozzles 24 and 24 on the upper and lower surfaces of the substrate Wf to be cleaned. Thereafter, the swing arm 111 is moved, and the substrate to be cleaned Wf is spin-dried.

FIGS. 4 and 5 are views showing the structure of a substrate polishing apparatus using the substrate cleaning apparatus according to the present invention. FIG. 4 is a plan view and FIG. 5 is a sectional view. The substrate polishing apparatus is entirely surrounded by a partition 100, and includes a polishing section 30, a cleaning section 5
0, a load / unload unit 70.
A partition 101 is provided between the polishing unit 30 and the cleaning unit 50, and a partition 102 is provided between the cleaning unit 50 and the load / unload unit 70. The transfer of the substrate to be polished between the adjacent parts is performed through openings provided in the partition walls 101 and 102.

Load / unload section 70 of substrate polishing apparatus
Is connected to the clean room CR, and the other parts are separated from the maintenance room M by partitions.
It is installed at R. The polishing section 30 is a turntable 31
And a top ring unit 33 having a top ring 32 that presses against the turntable 31 while holding the substrate to be polished. The turntable 31 is a driving unit 3
8 enables rotation about the axis center. A polishing cloth 34 is attached to the upper surface of the turntable 31.

The top ring unit 33 is swingable, and the top ring 32 is arranged at a transfer position above a pusher 37 for transferring a substrate to be polished at a polishing position on the turntable 31 and a standby position. It has become. The top ring 32 is connected to a motor and a cylinder (not shown). Thus, the top ring 32 can move up and down and rotate around its axis, so that the substrate to be polished can be pressed against the polishing cloth 34 with an arbitrary pressure. The substrate to be polished is attracted to the lower end surface of the top ring 32 by vacuum or the like. A polishing liquid supply nozzle (not shown) is provided above the turntable 31 so that the polishing liquid is supplied to the polishing cloth 34 on the turntable 31 by the polishing liquid supply nozzle. The dressing unit further includes a dresser unit 36 having a dresser 35 for conditioning the polishing cloth 34.

The cleaning section 50 is installed at the center,
Two transfer robots 51 and 52 that can move in the directions shown in FIG.
, A primary cleaning machine 53, a secondary cleaning machine 54, a tertiary cleaning machine 55, and reversing machines 56 and 57 for reversing a substrate to be polished. A cassette 71 for accommodating a substrate to be polished is placed on the loading / unloading section 70 installed adjacent to the cleaning section 50. The substrate to be polished in the cassette 71 is received by the transfer robot 52 and transferred to the reversing device 56, where it is turned over, and then transferred to the pusher 37 of the polishing section 30 by the transfer robot 51.

The substrate to be polished by the polishing section 30 is transferred by a transfer robot 51 to a reversing device 57, where the substrate is reversed, and a primary cleaning device 53, a secondary cleaning device 54,
It is sequentially sent to the tertiary washing machine 55. After being washed and spin-dried by the tertiary washing machine 55, it is returned to the cassette 71 of the loading / unloading section by the transfer robot 52. As shown in FIG. 4, an exhaust duct 58 for discharging the air in the cleaning unit 50 to the outside is provided on the partition wall of the cleaning unit 50. The exhaust duct 58 communicates with the outside. In FIG. 5, the tertiary washing machine 55 is omitted because the exhaust duct 58 is shown.

The polishing liquid mist and generated gas generated in the polishing section 30 during polishing of the substrate to be polished are exhausted from the exhaust duct 39 together with dust on the drive belt of the drive section 38 of the turntable 31. Also, a primary cleaning machine 53 and a secondary cleaning machine 54
Then, the mist (chemical solution, ultrapure water) of the cleaning liquid generated in the tertiary cleaning device 55 is exhausted from the exhaust duct 58 ′ through the exhaust port 17. The air corresponding to these exhaust air flows from the cassette delivery port 72 to the clean room CR.
The clean air inside the cleaning unit 50 flows into the cleaning unit 50, and the air flowing from the suction port 90 of the filter block 80 further flows into the cleaning unit 50.
Substrate delivery port 10 provided in partition 101
1a is supplied into the polishing section 30.

The filter block 80 has a built-in fan 81. The outlet of the fan 81 has a filtration accuracy of 0.1 μm.
The HEP filter 82 is attached to the fan 81, and a chemical filter 83 for adsorbing and removing harmful gas is attached to the inlet side of the fan 81. The clean air from the HEP filter 82 is transferred to the moving range of the transfer robots 51 and 52 and the primary cleaning machine 53.
, The secondary cleaning device 54 and the tertiary cleaning device 55, that is, blown down into the moving range of the substrate to be polished, a part of the blown down air flows to the polishing section 30 described above, and most of the air is blown down. It descends to the equipment floor.

A duct header 59, which is a flat box-shaped tube, is mounted on the floor surface. The duct header 59 is provided with a large number of holes 60, and the holes 60 have blades (FIG. (Not shown). Duct header 59
Are connected to a filter block 80 by a duct 61. The air that has descended to the floor of the apparatus is sucked through the hole 60, collected in the duct header 59, and drawn into the chemical filter 83 through the duct 61.

The substrate cleaning apparatus 10 having the structure shown in FIG. 1 is used for at least one of the primary cleaning machine 53, the secondary cleaning machine 54, and the tertiary cleaning machine 55 (in the figure, the substrate cleaning apparatus shown in FIG. 1). Device), the exhaust from the exhaust ports 17, 17 flows to the exhaust duct 58 '. Accordingly, when the pressure P _IN in the cleaning tank 11 is smaller than the pressure P _OUT outside the cleaning tank 11 (inside the cleaning unit 50), that is, when P _IN <P _OUT , the gap between the baffle plates 13 and 13 Clean air is introduced into the cleaning tank 11 through the inlet port 12, forms a downflow in the tank, is discharged from the exhaust ports 17, 17, and is discharged to the exhaust duct 58 '.

In this down-flow atmosphere, a diluted hydrofluoric acid (DHF) solution or the like is ejected from the chemical solution nozzles 23, 23 as the chemical solution onto the upper and lower surfaces of the substrate Wf to be cleaned which is held and rotated by the substrate holding and rotating mechanism 18. Then, the substrate Wf to be cleaned is cleaned with a chemical solution. Subsequently, ultrapure water is sprayed from the pure water nozzles 24 onto the upper and lower surfaces of the substrate Wf to be cleaned, and the substrate Wf to be cleaned is cleaned with pure water. Subsequently, the substrate to be cleaned Wf is rotated at a high speed by the high-speed rotation of the substrate holding / rotating mechanism 18, and the centrifugal force removes droplets adhering to the surface to spin dry the substrate to be cleaned Wf.

When the operation is stopped due to a failure of the exhaust system connected to the exhaust duct 58 ', or when P _IN ≥P _OUT , the control unit 28 starts the pump 16 as shown in FIG. Ultrapure water is jetted from the nozzles 14, 14 to form water curtains 15, 15, and the water curtains 15, 15 cover the air inlet 12. As a result, a mist of a chemical solution or the like which is going to be scattered to the outside through the intake port 12 is removed by the water curtain 1.
It is absorbed by 5, 15 and does not scatter outside.

In the above example, a substrate polishing apparatus for polishing a substrate has been described as an example of a substrate processing apparatus according to the present invention. However, after performing some processing on the substrate, the processed substrate is cleaned. If the substrate processing apparatus has a cleaning unit to
Obviously, the substrate cleaning apparatus according to the present invention can be used.

[0033]

As described above, according to the first to third aspects of the present invention, the following excellent effects can be expected.

(1) Since a water curtain forming means is provided so that the air inlet can be covered with a curtain made of water, there is a possibility that a cleaning liquid mist or the like may be scattered from the inside of the cleaning tank through the air inlet ( For example, when the exhaust system stops due to a failure or when the internal pressure of the cleaning tank becomes higher than the external pressure for some reason), by covering the intake port with a curtain of water, the chemical mist etc. It is possible to provide a substrate cleaning apparatus that is absorbed and does not fly out of the cleaning tank through the air inlet, thereby preventing diffusion of a chemical solution atmosphere and preventing re-adhesion of mist during drying.

(2) Since chemical cleaning and spin drying can be performed in one tank, the size of the apparatus can be reduced.

According to the fourth aspect of the present invention, since the substrate cleaning apparatus according to any one of the first to third aspects is used in the substrate cleaning section, the diffusion of the chemical solution atmosphere from the cleaning section is prevented, and the cleaning section is used. It is possible to provide a substrate processing apparatus capable of preventing mist from re-adhering when the substrate is dried. In addition, when the exhaust system is stopped due to a failure of the exhaust system of the substrate cleaning apparatus or when the pressure in the cleaning tank is equal to or higher than the pressure outside the cleaning tank, the intake port at the top of the cleaning tank is covered with a curtain made of water. A substrate processing apparatus can be provided in which a chemical mist or the like does not scatter outside the cleaning tank and an atmosphere of a cleaning liquid (chemical liquid or the like) does not diffuse outside the cleaning tank.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration example of a substrate cleaning apparatus according to the present invention.

FIG. 2 is a diagram showing a configuration example of a suction port portion and a water curtain forming means of the substrate cleaning apparatus of FIG. 1;

FIG. 3 is a diagram illustrating a configuration example of a cleaning mechanism of the substrate cleaning apparatus according to the present invention.

FIG. 4 is a plan view showing a schematic configuration example of a substrate polishing apparatus according to the present invention.

FIG. 5 is a cross-sectional view illustrating a schematic configuration example of a substrate polishing apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Substrate cleaning apparatus 11 Cleaning tank 12 Intake port 13 Baffle plate 14 Water injection nozzle 15 Water curtain 16 Pump 17 Exhaust port 18 Substrate holding / rotating mechanism 19 Nipping member 20 Base 21 Rotating shaft 22 Sealing mechanism 23 Chemical nozzle 24 Pure water nozzle 25 Drain hole 26 Internal pressure sensor 27 External pressure sensor 28 Control unit 29 Exhaust system stop signal 30 Polishing unit 50 Cleaning unit 70 Load / unload unit 80 Filter block

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3B116 AA03 AB14 AB23 AB34 BA02 BA08 BA13 BB24 BB87 CC01 CC03 CD34 3B201 AA03 AB14 AB23 AB34 BA02 BA08 BA13 BA34 BB24 BB62 BB87 BB92 BB93 BB94 CB12 CC01 CC13 CD11 CD34

Claims (4)

[Claims] 1. A cleaning tank is provided, an intake port is provided at an upper part of the cleaning tank, an exhaust port is provided at a bottom part, a down flow is formed in the cleaning tank, and a substrate to be cleaned is rotated in the cleaning tank. A substrate cleaning apparatus capable of cleaning and drying the substrate to be cleaned in the same cleaning tank, wherein the substrate is provided with water curtain forming means for covering the intake port with a curtain of water. Cleaning equipment. 2. The substrate cleaning apparatus according to claim 1, wherein the water curtain forming means is provided when the exhaust system to which the exhaust port is connected fails or when the internal pressure P _{IN of the} cleaning tank is equal to or higher than the external pressure P _OUT. A substrate cleaning apparatus characterized in that when (P _IN ≧ P _OUT ), the air inlet is covered with a curtain of water. 3. The substrate cleaning apparatus according to claim 1, wherein a baffle plate for preventing the droplets from scattering from the inside of the cleaning tank is provided at the intake port. 4. A load / unload section for loading and unloading a substrate to be processed, a substrate processing section for processing a substrate to be processed, a substrate cleaning section for cleaning and drying the substrate to be processed, and a substrate transport mechanism for transporting the substrate to each section. Comprising, by the substrate transfer mechanism,
Take out the unprocessed substrate from the loading / unloading unit, transport the substrate to the substrate processing unit, transport the substrate to be processed in the substrate processing unit to the substrate cleaning unit, and clean the substrate in the substrate cleaning unit. In a substrate processing apparatus that transports and stores a dried substrate to be loaded and unloaded in the loading / unloading section, at least one cleaning apparatus is installed in the substrate cleaning section, and at least one of the cleaning apparatuses is charged. A substrate processing apparatus using the substrate cleaning apparatus according to any one of Items 1 to 3.