JP2019201068A - Cleaning method, cleaning device and semiconductor wafer holding device - Google Patents

Abstract

To enable cleaning of the front side surface and the rear side surface of an object to be cleaned with efficiency.SOLUTION: Cleaning liquid containing microbubble is supplied to the front side surface 1 of an object W to be cleaned from a first injection nozzle 11 and to the rear side surface 2 of the object W to be cleaned from a second injection nozzle 12. The object W to be cleared (for example, semiconductor wafer) arranged on a turntable 51 in a horizontal state is held by a holding mechanism 60 provided on the turntable 51. In addition to an oscillating part 63, each holding mechanism 60 includes: a pressing part (small diameter part 64b) held by the oscillating part 63; a weight part (pin part 65); and a support part (large diameter parts 64a, 65a). The greater the number of revolution of the turntable 51, the greater the centrifugal force acting on the weight part (65). Then, the pressing force (pressure contact force) onto the side end surface 3 by the pressing part (64b) is increased.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cleaning method, a cleaning apparatus, and a semiconductor wafer holding apparatus.

  For example, in the case of an object to be cleaned such as a semiconductor wafer, cleaning for removing attached particles, organic substances, and the like is performed. Patent Document 1 discloses one that uses ozone water as a cleaning liquid. Patent Document 2 discloses an injection nozzle that generates a microvalve when a cleaning solution in which ozone is dissolved is passed, for example, for cleaning a semiconductor wafer, and injects the cleaning solution including the microvalve. Yes.

JP 2010-177535 A JP 2017-191855 A

  By the way, when the object to be cleaned is a thin object, for example, when it is a thin leaf like a semiconductor wafer, it is desirable to clean the front side surface and the back side surface, but how to perform the cleaning efficiently. It becomes important.

  In addition, for example, when cleaning a thin wafer like a semiconductor wafer while rotating in a horizontal state, it is desirable to hold the semiconductor wafer on its side end surface in order to clean the front side surface and the back side surface. become. On the other hand, as the thickness of the semiconductor wafer becomes thinner, if the holding force at the side end surface thereof, particularly the holding force toward the radially inner side becomes too large, the semiconductor wafer is damaged (buckled). The problem is that the possibility increases.

  The present invention has been made in view of the above circumstances, and a first object of the present invention is to provide a cleaning method capable of efficiently cleaning the front side surface and the back side surface of a thin object to be cleaned. There is to do.

  A second object of the present invention is to provide a cleaning apparatus suitable for use in carrying out the above cleaning method.

  The third object of the present invention is to prevent a semiconductor wafer from being accidentally damaged by receiving a holding force when a semiconductor wafer as a thin leaf is held on its side end face. It is in providing a holding device.

In order to achieve the first object, the following first solution is adopted in the present invention. That is, as described in claim 1,
A cleaning liquid including a microvalve is supplied from the first injection nozzle to the front side surface of the thinned cleaning object to clean the front side surface of the cleaning target object, and the back side surface of the cleaning target object is (2) A cleaning liquid containing a microvalve is supplied from the spray nozzle to clean the back side of the cleaning object.
It is like that. According to the above solution, since the front side surface and the back side surface of the object to be cleaned can be cleaned at the same time, the cleaning efficiency is improved as compared with the case where the front side surface and the back side surface are cleaned in separate steps. In addition, since cleaning is performed with a cleaning solution that includes a microvalve, the cleaning effect can be increased and cleaning time can be shortened, and cleaning efficiency can be further improved compared to cleaning with a cleaning solution that does not include a microvalve. be able to.

A preferable aspect based on the first solution is as described in claims 2 to 9. That is,
The object to be cleaned is a thin leaf,
While rotating the object to be cleaned around a predetermined rotation axis extending in the vertical direction, the cleaning liquid including the microvalves from the first injection nozzle and the second injection nozzle is respectively brought near the rotation center of the object to be cleaned. Supply,
(Corresponding to claim 2). In this case, the cleaning liquid including the microvalve supplied to the object to be cleaned is allowed to flow from the vicinity of the rotation center of the object to be cleaned toward the outer peripheral edge, so that a wide area range between the front side surface and the back side surface of the object to be cleaned Can be washed uniformly.

  The object to be cleaned is a semiconductor wafer (corresponding to claim 3). In this case, the effects described above can be obtained for the cleaning of the semiconductor wafer.

The object to be cleaned is held in advance by a plurality of holding mechanisms provided on a turntable rotated around the rotation axis,
Then, while rotating the object to be cleaned by rotating the turntable, a cleaning liquid including a micro valve is supplied to the object to be cleaned from the first injection nozzle and the second injection nozzle.
(Corresponding to claim 4). In this case, a specific mode for supplying the cleaning liquid including the microvalve to the vicinity of the rotation center of the cleaning target is provided.

  The plurality of holding mechanisms press the side end surface of the cleaning object on the turntable by the action of centrifugal force when the turntable is rotated while supporting the outer peripheral edge of the cleaning object from below. (Corresponding to claim 5). In this case, the centrifugal force generated by the rotation of the turntable can be effectively used to appropriately obtain a pressing force for holding the side end surface of the object to be cleaned. Moreover, the situation which carelessly presses the side end surface of the cleaning target object is prevented, which is preferable in preventing the cleaning target object from being damaged.

A through hole is formed in the rotation center of the turntable,
A cleaning liquid including a micro valve from the second injection nozzle is injected upward through the through-hole.
(Corresponding to claim 6). In this case, a specific supply mode of the cleaning liquid including the microvalve from below can be provided.

The object to be cleaned is thin and long,
A cleaning liquid including a micro valve is supplied from the first injection nozzle and the second injection nozzle at a predetermined position in the conveyance path where the object to be cleaned is conveyed by roll-to-roll.
(Corresponding to claim 7). In this case, when the object to be cleaned is thin and long, the same effect as the effect corresponding to claim 1 can be obtained.

  The cleaning object is transported in an inclined state so as to be directed downward immediately after passing through the predetermined position (corresponding to claim 8). In this case, the cleaning liquid including the microvalve supplied to the object to be cleaned can be effectively discharged at the inclined portion.

  The cleaning liquid is pure water in which ozone is dissolved (corresponding to claim 9). In this case, ozone can be converted into a microvalve to obtain a strong cleaning effect.

In order to achieve the second object, the following second solution is adopted in the present invention. That is, as described in claim 10,
A cleaning device for cleaning the front side and the back side of a thin object to be cleaned,
A turntable that is driven to rotate about a rotation axis extending in the vertical direction;
A holding mechanism provided on the turntable for holding the object to be cleaned in a horizontal state in which either one of the front side surface and the back side surface is directed upward;
A first injection nozzle disposed above the object to be cleaned held by the holding mechanism and directed to the upper surface of the object to be cleaned and near the center of rotation of the object to be cleaned;
A second injection nozzle disposed below the object to be cleaned held by the holding mechanism and directed to the lower surface of the object to be cleaned and near the rotation center of the object to be cleaned;
A dissolution tank for storing a cleaning liquid in which the cleaning gas is dissolved;
A pump for pumping the cleaning liquid in the dissolution tank to the first injection nozzle and the second injection nozzle;
With
Each of the first injection nozzle and the second injection nozzle generates a microvalve in the process of passing the cleaning liquid pumped from the dissolution tank, and injects the cleaning liquid including the microvalve;
It is like that. According to the second solution technique, it is possible to provide a cleaning apparatus for executing the cleaning method according to claims 4 and 5.

Preferred embodiments based on the second solution are as described in claims 11 to 14. That is,
The turntable has a through hole on the rotation axis,
The second spray nozzle is directed toward the through hole, and a cleaning liquid including a microvalve from the second spray nozzle is supplied to the lower surface of the object to be cleaned through the through hole.
(Corresponding to claim 11). In this case, a cleaning apparatus for executing the cleaning method according to claim 6 can be provided.

The rotating shaft of the turntable is hollow and aligned with the through hole,
The second injection nozzle is disposed in the rotating shaft;
This is done (corresponding to claim 12). In this case, the second injection nozzle can be disposed by effectively using the space in the rotation shaft.

Each of the first injection nozzle and the second injection nozzle has a nozzle body portion and a guide nozzle portion,
The nozzle body generates a microvalve in the process of passing a cleaning liquid in which a cleaning gas is dissolved, and discharges the cleaning liquid including the microvalve into the induction nozzle.
The induction nozzle suppresses a rapid pressure drop of the cleaning liquid including the microvalve discharged from the nozzle body, and jets the cleaning liquid including the microvalve vigorously.
(Corresponding to claim 13). In this case, the cleaning liquid including the microvalve can be ejected toward the object to be cleaned with sufficient momentum. Moreover, it becomes possible to arrange | position the injection | spray nozzle in the position considerably spaced apart from the washing | cleaning target object, and it becomes preferable also from raising the freedom degree of injection | spray nozzle arrangement | positioning.

Three or more holding mechanisms are provided at substantially equal intervals in the circumferential direction at the outer peripheral edge of the turntable,
Each of the plurality of holding mechanisms includes a swinging part that is swingably held around a swinging axis that extends in the vertical direction with respect to the turntable, and is provided on the swinging part so as to be outside the object to be cleaned. A support portion on which a peripheral edge portion is seated; and provided at a position eccentric to the swing axis of the swing portion, and approaches the side end surface of the object to be cleaned according to the swing of the swing portion. A pressing portion that is spaced apart, and a weight portion provided on the opposite side of the pressing portion across the swing axis of the swinging portion,
When the turntable is rotated, the oscillating portion is oscillated by a centrifugal force acting on the weight portion, so that the pressing portion presses a side end surface of the object to be cleaned.
(It corresponds to claim 14). In this case, a specific configuration for obtaining an appropriate pressing force using centrifugal force is provided.

In order to achieve the third object, the following third solution is adopted in the present invention. That is, as described in claim 15,
A holding device for rotatably holding a semiconductor wafer in a horizontal state,
A turntable that is driven to rotate about a rotation axis extending in the vertical direction;
A holding mechanism for holding the semiconductor wafer in a horizontal state, provided on an outer peripheral edge of the turntable;
With
Three or more holding mechanisms are provided at substantially equal intervals in the circumferential direction at the outer peripheral edge of the turntable,
Each of the plurality of holding mechanisms includes a swinging part that is swingably held around a swinging axis extending in the vertical direction with respect to the turntable, and an outer peripheral edge of the semiconductor wafer provided on the swinging part. A support portion on which a portion is seated, and a portion of the oscillating portion that is eccentric from the oscillating axis, and is moved toward and away from the side end surface of the semiconductor wafer according to the oscillating portion of the oscillating portion. And a weight portion provided on the side opposite to the pressing portion across the swing axis of the swing portion,
When the turntable is rotated, the pressing portion presses a side end surface of the semiconductor wafer by the swinging portion being swung by a centrifugal force acting on the weight portion;
It is like that. According to the above solution, a preferable holding device for rotating and holding a semiconductor wafer as a thin leaf is provided. In particular, as in the case of the fifth aspect, it is possible to appropriately obtain the holding pressing force against the side end surface of the semiconductor wafer by effectively utilizing the centrifugal force generated by the rotation of the turntable. In addition, a situation in which the side end surface of the semiconductor wafer is carelessly strongly pressed can be prevented, which is preferable in preventing the semiconductor wafer from being damaged.

  According to the present invention, an object to be cleaned can be efficiently cleaned and can be held with an appropriate pressing force without damaging the object to be cleaned and the semiconductor wafer.

The whole system figure which shows embodiment in case a washing | cleaning target object is a semiconductor wafer. The top view which shows the turntable which hold | maintains the semiconductor wafer shown in FIG. 1 rotatably. The principal part perspective view which shows the part holding the semiconductor wafer. The top view which shows the state of the holding | maintenance part at the time of a turntable stop. The top view which shows the state of the holding | maintenance part at the time of turntable rotation. The principal part sectional drawing which shows the example of arrangement | positioning of the 2nd injection nozzle arrange | positioned under the turntable. Sectional drawing which shows an example of an injection nozzle. The simplified side view which shows embodiment in case a washing | cleaning target object is a thin elongate object.

  In FIG. 1, W is a thin object to be cleaned. The object to be cleaned W has a thin leaf shape, and is a disk-shaped semiconductor wafer in the embodiment. The cleaning object W is in a posture extending in the horizontal direction, its upper surface is denoted by reference numeral 1, its lower surface is denoted by reference numeral 2, and its side end surface is denoted by reference numeral 3.

  Above the object to be cleaned W, the first injection nozzle 11 is disposed. A second spray nozzle 12 is disposed below the cleaning target W. Each of the spray nozzles 11 and 12 is directed toward the vicinity of the rotation center in the cleaning target W. Then, the cleaning liquid including the micro valve is sprayed from the first spray nozzle 11 and the second spray nozzle toward the vicinity of the rotation center of the cleaning target W.

  A cleaning liquid in which a cleaning gas (ozone in the embodiment) is dissolved is pumped to the spray nozzles 11 and 12. In the process in which the cleaning liquid passes through the injection nozzles 11 and 12, a microvalve is generated. The cleaning liquid including the microvalve is simultaneously sprayed from the first spray nozzle 11 and the second spray nozzle 12, and the top surface 1 and the bottom surface 2 of the cleaning target W are cleaned simultaneously.

  Next, a configuration of a portion that generates the cleaning liquid in which the cleaning gas (ozone in the embodiment) is dissolved will be described. First, 20 is a sealed mixing tank. An ozone generating device 22 for generating ozone as a cleaning gas is connected to the mixing tank 20 via a pipe 39. The piping 39 is connected to a regulating valve 40 (in the embodiment, an air operating valve that is opened and closed in an on / off manner). The amount of ozone supplied to the mixing tank 20 is adjusted by the adjustment valve 40. The piping 39 is disposed in the mixing tank 20 and is opened in a cup member 41 that is opened downward.

  A cleaning liquid supply device 25 is connected to the mixing tank 20 via a pipe 24. The cleaning liquid is pure water in the embodiment. The piping 24 is connected to an adjustment valve 26 (in the embodiment, an air operation valve that is opened and closed in an on / off manner). The amount of cleaning liquid supplied to the mixing tank is adjusted by the adjusting valve 26.

The mixing tank 20 has a communication pipe 27a that is located outside and communicates with the upper part and the lower part.
Is connected. A liquid level sensor 27b is attached to the communication pipe 27a. The liquid level sensor 27b detects the liquid level height position in the communication pipe 27a. The adjustment valve 26 is controlled so that the liquid level height position detected by the liquid level sensor 27b falls within a predetermined height range. As the liquid level sensor 27b, an appropriate one such as one disposed in the mixing tank 20 can be used.

  In the figure, 30 is a dissolution tank having a sealed structure. The dissolution tank 30 is connected to the mixing tank 20 via a pipe 31. The piping 31 is opened in the cup member 41 described above in the mixing tank 20. A pressure-feed pump 32 is connected to the pipe 31. The cleaning liquid containing the cleaning gas in the mixing tank 20 is pumped to the dissolution tank 30 by the pump 32 for pumping. Although the positive displacement pump 32 uses a positive displacement pump in the embodiment, an appropriate type of pump such as a non-positive displacement pump can be used. In addition, as a positive displacement pump, a diaphragm pump, a gear pump, a piston pump, a plunger pump etc. can be used, for example.

  An injection pipe 33 is disposed in the dissolution tank 30 so as to extend in the vertical direction. The pipe 31 is connected to the lower end of the injection pipe 33. Further, the upper end of the injection pipe 33 is closed. A plurality of injection holes 33a are opened at an upper portion of the injection pipe 33 at intervals in the circumferential direction. At least some of the plurality of injection holes 33 a are located near the inner wall of the dissolution tank 30. The cleaning liquid pumped into the injection pipe 33 is injected into the dissolution tank 30 from the injection hole 33a, and the cleaning gas (ozone) is sufficiently dissolved in the cleaning liquid (pure water).

The dissolution tank 30 has a communication pipe 34a that is located outside and communicates with the upper part and the lower part.
Is connected. A liquid level sensor 34b is attached to the communication pipe 34a. The liquid level sensor 34b detects the liquid level height position in the communication pipe 34a. As the liquid level sensor 34b, an appropriate one such as one disposed in the dissolution tank 30 can be used.

  An upper space in the dissolution tank 30 is always provided with a space 35. This space 35 reduces the pulsation of the cleaning liquid in the dissolution tank 30. The dissolution tank 30 is connected with a pipe 36 that communicates with the space 35 and extends to the outside. Two adjustment valves 37 and 38 are connected to the pipe 36 in series. The regulating valve 37 is an air operated valve and is opened and closed in an on / off manner. The adjustment valve 38 is, for example, an electromagnetic type, and its opening degree can be finely adjusted.

  The adjustment valves 37 and 38 are controlled so that the liquid level height detected by the liquid level sensor 34b falls within a predetermined height range (at least the space 35 falls within the predetermined height range). Further, the pressure in the space 35 is controlled so as to be maintained at about 0.2 to 0.6 MPa.

  One end of a pipe 42 is connected to the bottom of the dissolution tank 30. The other end of the pipe 42 is connected to the first injection nozzle 11. A branch pipe 42 a branched from the pipe 42 is connected to the second injection nozzle 12. As a result, the cleaning liquid containing ozone having a high pressure in the dissolution tank 30 is supplied to the spray nozzles 11 and 12.

  A heater 45 (for example, an electric heater) is connected to the pipe 42 on the melting tank 30 side of the branch pipe 42a. Thereby, the cleaning liquid supplied to the injection nozzles 11 and 12 is managed at an appropriate temperature (for example, 40 ° C. to 60 ° C.).

  The piping 42 is connected to a regulating valve 46 (in the embodiment, an air operating valve that is opened and closed in an on / off manner) on the first injection nozzle 11 side with respect to the branch piping 42a. The branch pipe 42a is connected with a regulating valve 47 (in the embodiment, it is an air-operated valve that is opened and closed in an on / off manner). A first injection mode in which the cleaning liquid is injected from both the first injection nozzle 11 and the second injection nozzle 12 by controlling the adjustment valves 46 and 47, and a second injection in which the cleaning liquid is injected only from the first injection nozzle 11. It is possible to select the mode and the third spray mode in which the cleaning liquid is sprayed only from the second spray nozzle 12. Of course, an injection stop state in which the injection of the cleaning liquid from both the injection nozzles 11 and 12 is also selected. In the present embodiment, as a spraying mode for spraying the cleaning liquid, a first spraying mode in which the cleaning liquid is sprayed simultaneously from both the spray nozzles 11 and 12 is performed.

  The cleaning liquid containing ozone pressure-fed to each injection nozzle 11, 12 generates a micro valve in the process of passing through each injection nozzle 11, 12, and the cleaning liquid including the micro valve is injected from each injection nozzle 11, 12. Will be. In addition, the matter regarding the production | generation of the microvalve in each injection nozzle 11 and 12 is mentioned later.

  Next, an example of the holding device 50 that rotatably holds the cleaning target W will be described with reference to FIGS. First, as shown in FIG. 2, the holding device 50 includes a turntable 51 extending in the horizontal direction and a holding mechanism 60 held by the turntable 51. The turntable 51 has a hollow (cylindrical in the embodiment) rotating shaft 52 fixed at the center of the lower surface (see FIG. 6). The rotation shaft 52 extends in the vertical direction, and the axis of the rotation shaft 52 becomes the rotation axis α of the turntable 51.

  A through hole 51 a is formed in the center of the turntable 51. The through hole 51 a is concentric with the rotation shaft 52 and communicates with the rotation shaft 52 (facing the rotation shaft 52). In the hollow rotating shaft 52, the 2nd injection nozzle 12 is fixedly arranged in the state spaced apart to the rotating shaft 52 in radial direction (refer FIG. 6).

  The rotary shaft 52 is connected to a drive motor 53 via a gear, a belt, etc. (not shown). By driving and controlling the motor 53 by the controller U, the turntable 51 (and hence the cleaning object W held on the turntable 51) is rotationally driven. The controller U controls the aforementioned pressure pump 32 and the regulating valves 26, 37, 38, 40, 46, and 47 (for this reason, the signals from the liquid level sensors 27b and 34b are input to the controller U). Is supposed to be).

  The holding mechanism 60 is provided on the outer peripheral edge of the turntable 51. In the embodiment, a total of three holding mechanisms 60 are held at intervals of 180 degrees in the circumferential direction of the turntable 51.

  The holding mechanism 60 has a base portion 61 fixed to the turntable 51. The base portion 61 holds a swinging portion 63 via a connecting pin 62 so as to be swingable in the horizontal direction. The axis of the connecting pin 62 constitutes a swing axis β that extends in the vertical direction.

  A first pin portion 64 that extends short upward is fixed to one end portion of the swinging portion 63. The first pin portion 64 has a large and small atypical columnar shape, and a lower portion is a large diameter portion 64a and an upper portion is a small diameter portion 64b.

  A second pin portion 65 extending short upward is fixed to the other end portion of the swinging portion 63. The second pin portion 65 has a large and small atypical columnar shape, the lower portion is a large diameter portion 65a, and the upper portion is a small diameter portion 65b.

  The second pin portion 65 is located on the opposite side of the first pin portion 64 with the connecting pin 62 interposed therebetween. The second pin portion 65 forms a weight portion that is sufficiently heavier than the first pin portion 64.

  The upper surfaces of the large-diameter portions 64a and 65a of the pin portions 64 and 65 constitute a support portion that supports the outer peripheral edge portion of the cleaning object W from below. Each of the small diameter portions 64b and 65b is located on the radially outer side of the turntable 51 with respect to the cleaning target W supported by the large diameter portions 64a and 65a. The small-diameter portion 64 b (the side surface) of the first pin portion 64 can be brought into contact with and separated from the side end surface 3 of the cleaning target object W according to the swinging of the swinging portion 63. That is, the small diameter part 64b constitutes a pressing part (pressure contact part). A stopper portion 61a that restricts the swinging portion 63 from swinging more than a predetermined amount is formed at the end of the base portion 61 so as to protrude upward.

  FIG. 4 is when the turntable 51 is in a stopped state. In the state shown in FIG. 4, the outer peripheral edge portion of the cleaning target W is seated (supported from below) on the upper surfaces of the large-diameter portions 64a and 65a as the support portions. In this state, when the turntable 51 is rotationally driven in the direction indicated by the arrow γ in FIG. 5, for example, the second pin portion 65 serving as the weight portion is directed toward the radial direction of the turntable 51 due to the centrifugal force accompanying the rotation. You will receive external force. As a result, the oscillating portion 63 is oscillated clockwise in FIG. 5, and the small diameter portion 64 b (the side surface) of the first pin portion 64 as the pressing portion presses the side end surface 3 of the cleaning object W. (Press contact). The pressing force from the small diameter portion 634b is increased as the rotation number of the turntable 51 is increased.

  The pressing force of the small diameter portion 64b generated by the rotation of the turntable 51 is a direction toward the radially inner side of the cleaning target W. On the other hand, the cleaning object W receives a force directed radially outward in accordance with the rotation of the turntable 51. Therefore, the pressing force from the small-diameter portion 64b and the force toward the radial direction received by the cleaning target W are opposed to each other.

  Therefore, even if the rotation speed of the turntable 51 is increased and the pressing force of the small diameter portion 64b is increased, a situation in which the cleaning target W is buckled in the radial direction is prevented. Thus, the response pressure of the small diameter portion 64 b is appropriate according to the rotation speed of the handrail 51. Incidentally, when only the applied pressure of the small diameter portion 64b is increased without rotating the turntable 51, there is a high possibility that the cleaning object W is damaged (broken) due to buckling or the like.

  To return to the state of FIG. 4 from the state of FIG. 5, for example, it is performed by rotating the turntable 51 reversely (rotating in the direction opposite to the arrow γ) immediately before the rotation of the turntable 51 stops. it can. Further, for example, a return spring surrounding the connecting pin 62 can be used to return to the position shown in FIG.

  The installation and removal of the cleaning object W on the turntable 51 can be performed, for example, by a transfer robot in the state shown in FIG.

  Next, an example of each of the injection nozzles 11 and 12 will be described with reference to FIG. Since both the injection nozzles 11 and 12 have the same structure, the description will be given focusing on the first injection nozzle 11.

  The 1st injection nozzle 11 is divided roughly and is comprised by the nozzle main-body part 70 and the guidance nozzle part 80. FIG. Since the nozzle body 70 is similar to that described in Patent Document 2, it will be briefly described. An orifice 74, filters 75 a to 75 c, separation spacers 76 a to 76 c, and a fixed spacer 77 are disposed in the cleaning liquid flow path 71 in the nozzle body 70. The arrangement order is the order of the orifice 74, the separation spacer 76a, the filter 75a, the separation spacer 76b, the filter 75b, the separation spacer 76c, the filter 75c, and the fixed spacer 77 from the cleaning liquid inflow side. These parts can be removed from the nozzle body 70 and replaced.

  The orifice 74 is a disc having a predetermined thickness, and a circular hole is formed at the center thereof. The thickness of the orifice 74 is, for example, 3 mm. The diameter of the hole opened at the center of the orifice 74 is, for example, 0.5 mm.

  The filters 75a to 75c are discs having a plurality of small holes. The diameter of the plurality of small holes is, for example, 0.5 mm. The pitch of the plurality of small holes is, for example, 1.5 mm. The thickness of the filters 75a to 75c is, for example, 3 mm.

  The separation spacers 76a to 76c are discs having a predetermined thickness, and a circular hole is formed at the center thereof. The thickness of the separation spacers 76a to 76c is, for example, 0.4 mm. The diameter of the hole opened in the center of the separation spacers 76a to 76c is, for example, 8.0 mm.

  The fixed spacer 77 is a disc having a predetermined thickness, and a circular hole is formed in the center thereof. The thickness of the fixed spacer 77 is, for example, 3.2 mm. The diameter of the hole opened in the center of the fixed spacer 77 is, for example, 8.0 mm.

  When the cleaning liquid in which the cleaning gas is dissolved passes through the nozzle main body 70, the cleaning liquid including the microvalves is ejected from the nozzle main body 70. That is, the cleaning liquid in which the cleaning gas is dissolved passes through the orifice 74, the filters 75a to 75c, the separation spacers 76a to 76c, and the fixed spacer 77, thereby generating bubbles. 30 to 90% of the bubbles are microvalves (in the embodiment, the particle size is 1 to 50 μm, for example). The particle diameter of the microvalve is preferably as small as possible (there is no lower limit of the particle diameter), and is preferably 100 μm or less.

  The discharge pressure from the nozzle main body 70 can be set to, for example, about 0.1 MPa (pressure slightly higher than atmospheric pressure). By using the nozzle body 70, more microbubbles can be generated in the cleaning liquid containing ozone, and the cleaning power of the cleaning liquid can be further increased.

  The guide nozzle part 80 is closely fitted to the outer periphery of the nozzle body part 70. The guide nozzle portion 80 includes a small volume portion 81 and an elongated nozzle portion 82 extending from the small volume portion 81. The cleaning liquid including the microvalve ejected from the nozzle main body portion 70 is discharged to the small volume portion 81, but is prevented from being diffused widely toward the radial side. Thereby, it is prevented or suppressed that the pressure of the cleaning liquid including the microvalve is rapidly decreased. Then, the cleaning liquid including the microvalve having a certain pressure is ejected vigorously from the tip of the nozzle 82 by passing through the elongated nozzle portion 82.

  When the separation distance between the first spray nozzle 11 and the cleaning target W is small or when a large spray pressure is not required, the guide nozzle portion 80 may not be provided. However, by providing the guide nozzle portion 80, the momentum of injection can be increased or the directivity thereof can be increased.

  FIG. 8 shows a second embodiment of the present invention. In the present embodiment, the cleaning target WB is a long thin film such as a flexible semiconductor. The object to be cleaned WB is conveyed from the left side to the right side in the figure by a large number of rollers 91 (conveyance in a roll-to-roll system).

  The cleaning object WB sequentially passes through the first part L1, the second part L2, the third part L3, the fourth part L4, and the fifth part L5 in the transport process. The cleaning object WB is in a horizontal state in the first part L1, in a state inclined obliquely downward in the second part L2, in a horizontal state again in the third part L3, and obliquely upward in the fourth part L4. The inclined state is set, and the fifth portion L5 is set to the horizontal state again.

  In the first portion L1, the first injection nozzle 11 is disposed above the cleaning object WB, and the second injection nozzle 12 is disposed below the cleaning object WB. Each of the spray nozzles 11 and 12 is disposed in series in the transport direction, and is also disposed in parallel in the width direction of the cleaning object WB (the direction perpendicular to the paper surface).

  The cleaning liquid including the micro valve is simultaneously sprayed from the spray nozzles 11 and 12, and the upper surface and the lower surface of the cleaning target WB are cleaned simultaneously. The cleaning liquid including the ejected microvalve is dropped downward at the position of the second portion L2 inclined downward. The cleaning liquid including the dropped microvalve is collected in a collection box 92 disposed below each of the portions L1 to L4.

  Here, an experiment was conducted on the difference in cleaning effect between a cleaning solution including a microvalve and a cleaning solution not including a microvalve. The experiment was performed with a cleaning system as shown in FIG. As the cleaning object W, a semiconductor wafer was used. As an index indicating the cleaning effect, the dissolution rate of the i-line photoresist applied to the semiconductor wafer was used. Pure water was used as the cleaning liquid, and ozone (ozone water, concentration was 50 mg / L) was used as the cleaning gas.

  In an experiment at room temperature of 20 ° C., the dissolution rate of the i-line photoresist is 120 nm / min when a cleaning solution containing a microvalve is used, and 40 nm / min when the cleaning solution does not contain a microvalve (only pure water). min (the cleaning effect using the cleaning liquid containing the microvalve was tripled).

  In the experiment at a room temperature of 50 ° C., the dissolution rate of the i-line photoresist is 360 nm / min when a cleaning solution containing a microvalve is used, and 80 nm / min when the cleaning solution does not contain a microvalve (only pure water). min (the cleaning effect using the cleaning liquid containing the microvalve is 4.5 times).

  As is clear from the above experimental results, the cleaning effect (cleaning efficiency) can be remarkably improved by performing the cleaning using the cleaning liquid containing the microvalve.

Although the embodiments have been described above, the present invention is not limited to the embodiments, and appropriate modifications can be made within the scope of the claims.
(1) The path through which the cleaning liquid containing the cleaning gas passes (contacts) is preferably made of, for example, fluororesin or coated with fluororesin. In particular, it is preferable to form or coat with PCTFE (polychlorotrifluoroethylene).
(2) As the cleaning gas, an appropriate gas such as oxygen, argon, nitrogen, or hydrogen can be used in addition to ozone.
(3) As the cleaning liquid, in addition to pure water, an appropriate cleaning liquid such as an organic solvent, an aqueous sulfuric acid solution, an aqueous ammonia solution, or a slurry can be used.
(4) The apparatus for rotatably holding the semiconductor wafer as the cleaning object W is not limited to that shown in FIGS. 2 to 6, and an appropriate apparatus can be used.
(5) The holding mechanism 60 may be four or more. Further, the swing part 63 may be directly held on the turntable 51 so as to be swingable without the base part 61.
(6) The shapes of the first pin portion 64 and the second pin portion 65 can each be set to an appropriate shape other than a cylinder. However, the shape of the pressing portion (small diameter portion 64b) that presses the side end surface 3 of the cleaning target W is a cylindrical surface so that the surface in contact with the cleaning target W is a contact (pressing) in an area as small as possible. It is preferable to set so that
(7) The object held by the holding mechanism 60 provided on the turntable 51 may be held for an application other than cleaning.
(8) Examples of the object to be cleaned according to the present invention include, but are not limited to, a semiconductor wafer, a liquid crystal substrate, a solar cell substrate, a glass substrate, and a mask blank that require high-level cleaning. In addition, the present invention can be applied to, for example, cleaning of various parts in the field of electronic industry, medical field (such as cleaning of internal organs), and also to various metal products (for example, machine parts) and synthetic resin products. it can.
(9) The cleaning liquid including the microvalve is not limited to being generated by the injection nozzles 11 and 12, but can be generated in advance in the dissolution tank 30, for example. In this case, for example, by forming a circulation path through which the cleaning liquid is circulated in the dissolution tank 30 and connecting an injection nozzle corresponding to the injection nozzle 11 (12) to the discharge side end of the circulation path, the dissolution tank A cleaning liquid containing microvalves can be generated within 30.
(10) The objects of the present invention are not limited to those specified, but implicitly include providing what is substantially preferred or expressed as an advantage.

  The present invention is preferable, for example, for efficiently cleaning a semiconductor wafer.

W: Object to be cleaned (semiconductor wafer)
U: Controller α: Rotation axis β: Swing axis γ: Direction of rotation 1: Upper surface 2: Lower surface 3: Side end surface 11: First injection nozzle 12: Second injection nozzle 20: Mixing tank 22: Ozone generator 30: Melting Tank 32: Pressure pump 50: Holding device 51: Turntable 51a: Through hole 52: Rotating shaft 53 Drive motor 60: Holding mechanism 61: Base portion 62: Connecting pin (swing center)
63: oscillating part 64: first pin part 64a: large diameter part (supporting part)
64b: Small diameter part (pressure contact part)
65: 2nd pin part (weight part)
65a: Large diameter part (support part)
65b: Small diameter part 70: Nozzle body part 80: Guide nozzle part 81: Small volume part 82: Nozzle part WB: Object to be cleaned (FIG. 8)
L1: 1st part (FIG. 8)
L2: 2nd site | part (FIG. 8)
91: Roller (Fig. 8)
92: Collection box (Figure 8)

Claims (15)

  A cleaning liquid including a microvalve is supplied from the first injection nozzle to the front side surface of the thinned cleaning object to clean the front side surface of the cleaning target object, and the back side surface of the cleaning target object is 2. A cleaning method, comprising: supplying a cleaning liquid including a microvalve from a jet nozzle to clean the back side of the object to be cleaned. In claim 1,
The object to be cleaned is a thin leaf,
While rotating the object to be cleaned around a predetermined rotation axis extending in the vertical direction, the cleaning liquid including the microvalves from the first injection nozzle and the second injection nozzle is respectively brought near the rotation center of the object to be cleaned. Supply,
A cleaning method characterized by the above. In claim 2,
A cleaning method, wherein the object to be cleaned is a semiconductor wafer. In claim 2 or claim 3,
The object to be cleaned is held in advance by a plurality of holding mechanisms provided on a turntable rotated around the rotation axis,
Then, while rotating the object to be cleaned by rotating the turntable, a cleaning liquid including a micro valve is supplied to the object to be cleaned from the first injection nozzle and the second injection nozzle.
A cleaning method characterized by the above. In claim 4,
The plurality of holding mechanisms press the side end surface of the cleaning object on the turntable by the action of centrifugal force when the turntable is rotated while supporting the outer peripheral edge of the cleaning object from below. The cleaning method characterized by the above-mentioned. In claim 4 or claim 5,
A through hole is formed in the rotation center of the turntable,
A cleaning liquid including a micro valve from the second injection nozzle is injected upward through the through-hole.
A cleaning method characterized by the above. In claim 1,
The object to be cleaned is thin and long,
A cleaning liquid including a micro valve is supplied from the first injection nozzle and the second injection nozzle at a predetermined position in the conveyance path where the object to be cleaned is conveyed by roll-to-roll.
A cleaning method characterized by the above. In claim 7,
The cleaning method according to claim 1, wherein the cleaning object is conveyed in an inclined state so as to be directed downward immediately after passing through the predetermined position. In any one of Claims 1 thru | or 8,
A cleaning method, wherein the cleaning liquid is pure water in which ozone is dissolved. A cleaning device for cleaning the front side and the back side of a thin object to be cleaned,
A turntable that is driven to rotate about a rotation axis extending in the vertical direction;
A holding mechanism provided on the turntable for holding the object to be cleaned in a horizontal state in which either one of the front side surface and the back side surface is directed upward;
A first injection nozzle disposed above the object to be cleaned held by the holding mechanism and directed to the upper surface of the object to be cleaned and near the center of rotation of the object to be cleaned;
A second injection nozzle disposed below the object to be cleaned held by the holding mechanism and directed to the lower surface of the object to be cleaned and near the rotation center of the object to be cleaned;
A dissolution tank for storing a cleaning liquid in which the cleaning gas is dissolved;
A pump for pumping the cleaning liquid in the dissolution tank to the first injection nozzle and the second injection nozzle;
With
Each of the first injection nozzle and the second injection nozzle generates a microvalve in the process of passing the cleaning liquid pumped from the dissolution tank, and injects the cleaning liquid including the microvalve;
A cleaning apparatus characterized by that. In claim 10,
The turntable has a through hole on the rotation axis,
The second spray nozzle is directed toward the through hole, and a cleaning liquid including a microvalve from the second spray nozzle is supplied to the lower surface of the object to be cleaned through the through hole.
A cleaning apparatus characterized by that. In claim 11,
The rotating shaft of the turntable is hollow and aligned with the through hole,
The second injection nozzle is disposed in the rotating shaft;
A cleaning apparatus characterized by that. In any one of Claims 10 to 12,
Each of the first injection nozzle and the second injection nozzle has a nozzle body portion and a guide nozzle portion,
The nozzle body generates a microvalve in the process of passing a cleaning liquid in which a cleaning gas is dissolved, and discharges the cleaning liquid including the microvalve into the induction nozzle.
The induction nozzle suppresses a rapid pressure drop of the cleaning liquid including the microvalve discharged from the nozzle body, and jets the cleaning liquid including the microvalve vigorously.
A cleaning apparatus characterized by that. 14. In any one of claims 10 to 13,
Three or more holding mechanisms are provided at substantially equal intervals in the circumferential direction at the outer peripheral edge of the turntable,
Each of the plurality of holding mechanisms includes a swinging part that is swingably held around a swinging axis that extends in the vertical direction with respect to the turntable, and is provided on the swinging part so as to be outside the object to be cleaned. A support portion on which a peripheral edge portion is seated; and provided at a position eccentric to the swing axis of the swing portion, and approaches the side end surface of the object to be cleaned according to the swing of the swing portion. A pressing portion that is spaced apart, and a weight portion provided on the opposite side of the pressing portion across the swing axis of the swinging portion,
When the turntable is rotated, the oscillating portion is oscillated by a centrifugal force acting on the weight portion, so that the pressing portion presses a side end surface of the object to be cleaned.
A cleaning apparatus characterized by that. A holding device for rotatably holding a semiconductor wafer in a horizontal state,
A turntable that is driven to rotate about a rotation axis extending in the vertical direction;
A holding mechanism for holding the semiconductor wafer in a horizontal state, provided on an outer peripheral edge of the turntable;
With
Three or more holding mechanisms are provided at substantially equal intervals in the circumferential direction at the outer peripheral edge of the turntable,
Each of the plurality of holding mechanisms includes a swinging part that is swingably held around a swinging axis extending in the vertical direction with respect to the turntable, and an outer peripheral edge of the semiconductor wafer provided on the swinging part. A support portion on which a portion is seated, and a portion of the oscillating portion that is eccentric from the oscillating axis, and is moved toward and away from the side end surface of the semiconductor wafer according to the oscillating portion of the oscillating portion. And a weight portion provided on the side opposite to the pressing portion across the swing axis of the swing portion,
When the turntable is rotated, the pressing portion presses a side end surface of the semiconductor wafer by the swinging portion being swung by a centrifugal force acting on the weight portion;
A semiconductor wafer holding device.

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