JP4364659B2 - Spin processing apparatus and spin processing method - Google Patents

Description

  The present invention relates to a substrate spin processing apparatus and a spin processing method for processing a substrate while holding the substrate on a rotary table and rotating the substrate together with the rotary table.

  For example, in the manufacturing process of a semiconductor device, there are a film forming process and a photo process for forming a circuit pattern on a substrate such as a semiconductor wafer. In these processes, the substrate is treated with a processing solution such as an etching solution using a spin processing apparatus, and then rinsed with a rinsing solution such as pure water, and then the rotating table is rotated at a high speed, whereby the above substrate is obtained. A drying process is performed to remove the rinse liquid remaining on the substrate.

  The spin processing apparatus has a processing tank as is well known, and a cup body is provided in the processing tank. A rotating table that is rotationally driven by a driving source is provided in the cup body. The rotary table is provided with a plurality of holding members for holding the outer peripheral portion of the substrate at predetermined intervals along the circumferential direction, and the substrate is detachably held on the rotary table by these holding members.

  Therefore, the substrate can be processed by holding the substrate on the rotary table, and rotating the rotary table to supply the processing liquid to the substrate. If the rotary table is rotated at a high speed after the processing, the substrate is It can be dried.

  In many cases, impurities are attached not only to the upper surface but also to the lower surface of the substrate. Therefore, in order to remove impurities adhering to the substrate, for example, a processing solution such as an etching solution is sprayed and supplied not only to the upper surface of the substrate but also to the lower surface by a nozzle, and the impurities remaining on the substrate are removed by etching. It is being done.

  When the upper and lower surfaces of the substrate are treated with the etching solution, a rinsing liquid made of pure water is sprayed and supplied to the upper and lower surfaces of the substrate by the nozzle body, and the etching solution remaining on the substrate is cleaned and removed. Next, by rotating the rotary table at a high speed, a drying process is performed to remove the rinsing liquid remaining on the substrate by centrifugal force.

  When the substrate is rinsed with the rinsing liquid, the rinsing liquid supplied to the lower surface of the substrate falls from the lower surface to the upper surface of the rotary table, and the rotary table is also rinsed. As a result, when the substrate is dried by rotating the rotary table at a high speed, the etching solution does not scatter in the form of mist from the rotary table. It becomes possible to prevent the cause.

  However, conventionally, when the substrate is rinsed with a rinsing liquid, the rinsing liquid is ejected from the nozzle toward the upper and lower surfaces of the substrate at a preset constant ejection speed. Therefore, although the rotary table is rinsed to some extent during the rinsing of the substrate, the rinsing liquid is sprayed only to a predetermined position on the lower surface of the substrate. It was difficult to rinse thoroughly. That is, the etching solution may remain on the rotary table.

  As a result, during the drying process of the substrate, the etching solution remaining on the rotary table is scattered in the form of a mist and may adhere to the dried substrate and cause contamination. In particular, the upper surface of the rotary table has many uneven portions. For this reason, the etching solution adhering to the uneven portion may not be easily removed during the rinsing process of the substrate.

  Therefore, the upper surface side of the rotary table is covered with a flat rectifying cover. This prevents the etchant from directly adhering to the upper surface of the turntable with many irregularities, and makes it difficult for turbulence to occur when the turntable is rotated at a high speed to dry the substrate.

  If the upper surface side of the turntable is covered with a flat rectifying cover, it is possible to reduce the etching liquid remaining on the turntable without being rinsed. However, as described above, the rinse liquid is sprayed at a constant spray speed from the nozzle that sprays the rinse liquid onto the lower surface of the substrate.

  For this reason, since the region where the rinse liquid bounced off the lower surface of the substrate reaches the rectifying cover is limited, the entire rectifying cover is not uniformly rinsed by the rinsing liquid, and the etching liquid may remain. As a result, the etching solution remaining on the rectifying cover during the drying process of the substrate may be scattered as a mist and adhere to the substrate, causing contamination.

  In particular, the rectifying cover is provided with a through hole for injecting an etching solution or a rinsing solution from the nozzle to the lower surface of the substrate. Therefore, the etching solution adhering to the inner peripheral edge of the through hole may be difficult to be removed by the rinsing solution during the rinsing process, so that the etching solution remaining on the portion tends to cause contamination of the substrate. is there.

  When rinsing the lower surface of the substrate, the present invention ensures that the processing liquid used in the previous step can be removed by the rinsing liquid, so that the substrate is dried at a high speed after the rinsing process. Another object of the present invention is to provide a spin processing apparatus and a spin processing method in which the substrate is not contaminated by the processing liquid.

The present invention is a spin processing apparatus for processing while rotating a substrate,
A rotating table,
A plurality of holding means for holding the substrate provided on the turntable;
Drive means for rotating the rotary table;
A first nozzle for supplying a processing liquid toward the lower surface of the substrate held by the turntable;
A second nozzle for supplying a rinsing liquid to the lower surface of the substrate processed by the processing liquid;
Comprising a speed control means for changing the spray speed of the rinse liquid sprayed from the second nozzle ;
The upper surface side of the turntable is covered with a rectifying cover, and a processing liquid sprayed from the first nozzle body and a rinsing liquid sprayed from the second nozzle body are formed in the central portion of the rectifying cover. The spin processing apparatus is characterized in that a through hole is formed to reach the lower surface of the substrate held by the rotary table .

  The speed control means preferably includes an opening / closing control valve provided in a liquid supply pipe for supplying a rinsing liquid to the second nozzle body, and a control means for controlling opening / closing of the opening / closing control valve.

  The speed control means may include a flow rate control valve provided in a liquid supply pipe for supplying the rinse liquid to the second nozzle body, and a control means for controlling the flow rate of the rinse liquid flowing through the flow rate control valve. preferable.

  The speed control means is configured to connect an opening / closing control valve and a flow rate control valve in series to form a flow rate control unit, and to supply a rinsing liquid to the second nozzle body with two flow rate control units arranged in parallel. It is preferable to have a control means for opening and closing at least an open / close control valve among the open / close control valve and the flow control valve of each of the flow rate control units as well as being connected to the pipe.

The present invention is a spin processing method for processing a substrate while rotating the substrate together with a rotary table whose upper surface is covered with a rectifying cover ,
Supplying the substrate to the turntable;
Rotating the substrate together with the rotary table;
A process of supplying a processing liquid through a through hole formed in the center of the rectifying cover on the lower surface of the substrate rotating together with the rotary table;
Supplying a rinsing liquid to the lower surface of the substrate treated with the processing liquid through the through hole of the rectifying cover, and rinsing processing;
And a step of changing a spray speed of a rinsing liquid supplied to the lower surface when the lower surface of the substrate is rinsed.

  According to the present invention, when the rinsing liquid is supplied to the lower surface of the substrate, if the rinsing liquid spraying speed is changed, the landing position of the rinsing liquid is changed according to the spraying speed, and therefore remains attached to the rotary table. It becomes possible to uniformly rinse the treatment liquid.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 4 show a first embodiment of the present invention, and FIG. 1 shows a spin processing apparatus. This spin processing apparatus has a cup body 1 indicated by a chain line in FIG. A through hole 2 is formed in the central portion in the radial direction of the bottom of the cup body 1, and a plurality of discharge pipes 1 a are connected to the peripheral portion at predetermined intervals in the circumferential direction.

  A cylindrical power transmission body 3 is provided in the through hole 2. This power transmission body 3 is rotationally driven by a control motor 4 which is a driving means. The control motor 4 includes a cylindrical stator 5 and a cylindrical rotor 6 that is rotatably inserted into the stator 5.

  The power transmission body 3 has a lower end brought into contact with the upper end surface of the rotor 6, and the portion is fixed by a screw 7. Therefore, the power transmission body 3 rotates integrally with the rotor 6. The control motor 4 is controlled by the control device 8 so that the rotation speed will be described later.

  A rotary table 11 is attached to an upper end portion of the power transmission body 3 protruding into the cup body 1. The rotary table 11 is formed by superposing a disc-like lower plate 12 and an upper plate 13, and a central portion of the lower plate 12 and the upper plate 13 communicates with the internal space of the power transmission body 3. A hole 14 is formed.

  Four support cylinders 15 are integrally formed around the upper plate 13 of the rotary table 11 at predetermined intervals in the circumferential direction, for example, at intervals of 90 degrees. A through hole 16 is formed in a portion of the lower plate 12 corresponding to the support cylinder portion 15.

  Bushings 17a and 17b are fitted into the support cylinder portion 15 and the through holes 16, respectively, and holding members 18 are rotatably supported by the bushings 17a and 17b. The holding member 18 has a shaft portion 19 supported by the bushes 17 a and 17 b and a head portion 20 having a larger diameter than the shaft portion 19 formed integrally with the upper end portion of the shaft portion 19.

  A taper member 21 is provided on the upper end surface of the head 20 at a position eccentric from the rotation center of the holding member 19. An engagement pin 22 projects from the upper end of the taper surface 21a of the taper member 21 in the inclination direction.

  Then, a substrate W such as a semiconductor wafer is provided on the taper member 21 provided on each holding member 19 with the lower surface of the peripheral portion placed on the taper surface 21a. In this state, when each holding member 19 is rotated in a predetermined direction, for example, clockwise, the taper member 21 rotates eccentrically. As a result, the peripheral portion of the substrate W rises along the tapered surface 21 a of the taper member 21, and the outer peripheral surface abuts on the engagement pin 22, so that the substrate W is integrated with the turntable 11 by the four holding members 19. Retained.

  When the holding member 19 is rotated counterclockwise, which is the opposite direction, the holding roller 22 rotates eccentrically in a direction away from the outer peripheral surface of the substrate W. As a result, the holding state of the substrate W by the four holding members 19 is released.

  As shown in FIG. 1, the lower end of the shaft portion 19 of the holding member 18 protrudes to the lower surface side of the rotary table 11, and a slave gear 25 is fitted to the protruding end portion. The child gear 25 fitted to the shaft portion 19 of each holding member 18 is meshed with the parent gear 26. The master gear 26 is rotatably held by the power transmission body 3 via a bearing 27.

  The master gear 26 is urged in a predetermined rotational direction, for example, counterclockwise by a spring 28 provided on the outer peripheral surface of the power transmission body 3. As a result, the child gear 25 rotates in the clockwise direction, and the holding member 18 interlocks with the rotation, and the taper member 21 rotates eccentrically, whereby the substrate W is moved to the rotating body 11 by the engagement pins 22 of the holding members 18. Retained.

  In order to release the holding state of the substrate W, the master gear 26 is rotated clockwise against the urging force of the spring 28 by a release mechanism (not shown). Specifically, the release mechanism prevents the master gear 26 from rotating, and in this state, the control table 4 rotates the turntable 11 clockwise. Accordingly, since the holding member 18 rotates counterclockwise, the holding state of the substrate W by the engagement pin 22 is released.

  A holding cylinder 31 is inserted into the power transmission body 3. A nozzle head 32 is attached to the upper end of the holding cylinder 31. The nozzle head 32 is formed with a recess 30 having an inverted conical cross section opened on the upper surface.

  The nozzle head 32 has a first nozzle 33 for injecting, for example, an etching liquid as a processing liquid toward the center of the lower surface of the substrate W held on the turntable 11 and a first nozzle for injecting a rinsing liquid made of pure water. Two nozzles 34 and a third nozzle (not shown) for injecting a gas such as nitrogen gas are formed with the tip opening on the inner surface of the recess 30. Further, the nozzle head 32 is formed with a drain hole 30 a having a tip opened at the lowermost end of the inner surface of the recess 30.

  A first liquid supply pipe 35 is connected to the rear end of the first nozzle 33, and a second liquid supply pipe 36 is connected to the rear end of the second nozzle 34. Further, a drainage pipe 37 is connected to the drainage hole 30a.

  The first liquid supply pipe 35 is connected to an etching liquid supply source (not shown) that supplies an etching liquid to the first nozzle. The second liquid supply pipe 36 is connected to a rinsing liquid supply source (not shown) that supplies a rinsing liquid to the second nozzle 34.

  In the middle of the second liquid supply pipe 36, as shown in FIG. 2, a flow rate control valve 38, an on-off control valve 39 and a check valve 40 for adjusting the pressure of the rinse liquid supplied from the supply source, that is, the flow rate. Are sequentially provided in series. The opening / closing control valve 39 is controlled to be opened / closed by a control device 41 as control means.

  As will be described later, when the rinsing liquid is supplied from the second nozzle 34 to the lower surface of the substrate W, the control device 41 controls the opening / closing control valve 39 to open / close at predetermined time intervals. Accordingly, since the rinsing liquid intermittently flows through the second supply pipe 36, the rinsing liquid spraying speed ejected from the second nozzle 34 also changes intermittently. That is, in the first embodiment, the opening / closing control valve 39 and the control device 41 constitute speed control means for controlling the spraying speed of the rinsing liquid sprayed from the second nozzle 34.

  The upper surface and outer peripheral surface of the rotary table 11 are covered with a rectifying cover 45. The rectifying cover 45 includes an opposing wall portion 46 that faces the lower surface of the substrate W held on the turntable 11, and a peripheral wall portion 47 that is provided on the peripheral edge of the opposing wall portion 46.

  In the facing wall portion 46, the etching liquid sprayed from the first nozzle 33, the rinse liquid sprayed from the second nozzle 34 and the gas sprayed from the third nozzle body reach the lower surface of the substrate W. A through hole 48 is formed.

The upper ends of the four holding members 18 erected on the upper surface of the turntable 11 protrude from the through hole 49 formed in the opposing wall portion 46 of the rectifying cover 45 to the upper surface side.
Further, similarly to the lower surface side, a first upper nozzle body 50 for injecting an etching liquid as a processing liquid onto the substrate W and a second upper nozzle body 51 for injecting a rinsing liquid are disposed above the turntable 11. ing.

  Next, an operation when the substrate W is processed by the spin processing apparatus having the above configuration will be described. The processing of the substrate W in this embodiment includes an etching process, a rinsing process, and a drying process as shown in FIG.

  First, the substrate W is held on the turntable 11, and the turntable 11 is moved to several tens to several hundreds r. p. The etchant is supplied from the first nozzle 33 and the first upper nozzle body 50 to the upper and lower surfaces of the substrate W while rotating at a low speed of m. The treatment with the etching liquid is performed not only on the upper and lower surfaces of the substrate W, but also by etching the etching liquid supplied to the upper surface from the radial central portion toward the outer peripheral portion and flowing along the outer peripheral surface by centrifugal force. Even done.

  A part of the etching solution sprayed and supplied from the first nozzle 33 to the lower surface of the substrate W flows from the central portion of the lower surface of the substrate W along the peripheral portion, etches the entire lower surface, and rebounds on the lower surface to etch the etching solution. Drops on the upper surface of the rectifying cover 45. A part of the etching solution also adheres to the inner peripheral edge portion of the through hole 48 formed in the rectifying cover 45.

  If the substrate W is etched with the etchant, the supply of the etchant is stopped, the rinse liquid is supplied, and the rinse process is performed. Thereby, the etching solution remaining on the upper and lower surfaces of the substrate W can be removed by washing as follows.

  That is, when the substrate W is rinsed, the control device 41 controls to change the spray speed of the rinse liquid sprayed and supplied from the second nozzle 34 to the lower surface of the substrate W. That is, the opening / closing control valve 39 is intermittently controlled to open / close by the control device 41 during the rinsing process. Therefore, in the rinsing process, the injection speed of the rinsing liquid injected from the second nozzle 34 repeatedly changes according to the opening / closing of the opening / closing control valve 39 shown in FIG.

  When the spraying speed of the rinsing liquid repeatedly changes, the arrival position of the rinsing liquid sprayed from the second nozzle 34 changes according to the change. That is, when the open / close control valve 39 is open, the rinsing liquid collides with a predetermined position on the lower surface of the substrate W at a predetermined speed as indicated by an arrow A in FIG. 4A, and the lower surface of the substrate W is rinsed. To do.

  When the open / close control valve 39 is closed, the rinsing liquid injection speed gradually decreases, so that the rinsing liquid hits the upper surface of the rectifying cover 45 and the peripheral portion of the through hole 48 as shown by the arrow B in FIG. Rinse the part. When the rinsing liquid spraying speed is further lowered, as shown by an arrow C in FIG. 4C, the rinsing liquid hits the concave portion 30 formed in the nozzle head 32 and rinses the surface of the concave portion 30. The rinse liquid in which the recess 30 is rinsed is discharged from the drain hole 30a through the drain pipe 37.

  As described above, when the opening / closing control valve 39 is repeatedly opened and closed to change the spray speed of the rinse liquid sprayed from the second nozzle 34, the position where the rinse liquid hits not only the lower surface of the substrate W but also the rectifying cover 45. It can be changed to the upper surface, the peripheral edge of the through hole 48 or the like. Therefore, the upper surface of the rectifying cover 45 and the inner peripheral edge portion of the through hole 48 that cannot be sufficiently rinsed only by causing the rinse liquid to collide with only a predetermined portion of the lower surface of the substrate W are reliably rinsed. be able to.

  As a result, when the substrate W is dried by rotating the turntable 11 at a high speed after the rinsing process, the upper surface of the rectifying cover 45 covering the upper surface side of the turntable 11, the inner peripheral portion of the through hole 48, and the nozzle head. It is possible to prevent the etching liquid from being scattered in the form of a mist from the 32 recesses 30 and the like.

  Therefore, it is possible to prevent the mist-like etching liquid from adhering to the substrate W during the drying process and contaminating the substrate W. That is, the drying process of the substrate W can be reliably performed without contaminating the substrate.

  In the first embodiment, the upper surface side of the turntable 11 is covered with the rectifying cover 45, but even if the upper surface side of the turntable 11 is not covered with the rectifying cover 45, By changing the spraying speed of the rinsing liquid sprayed from the nozzles 34, the rinsing liquid supplied to the lower surface of the substrate W can be used to uniformly and satisfactorily rinse the etching liquid adhering to the turntable 11.

  FIG. 5 and FIG. 6 are modifications of the speed control means showing the second embodiment and the third embodiment of the present invention, respectively.

  In the speed control means shown in FIG. 5, an opening / closing control valve 39, a flow rate control valve 38, and a check valve 40 are sequentially provided in series in the second liquid supply pipe 36. The control device 41 can control not only the opening / closing control valve 39 but also the flow rate control valve 38 to change the flow rate of the rinsing liquid flowing through the second supply pipe 36.

  Accordingly, when the opening / closing control valve 39 is opened and the rinsing liquid is injected from the second nozzle 34, the flow rate control valve 38 can change the injection speed of the rinsing liquid injected from the second nozzle 34. That is, as in the first embodiment, it is possible to change the injection speed of the rinsing liquid injected from the second nozzle 34 with higher accuracy than in the case where the open / close control valve 39 is only controlled to open and close. .

  The speed control means shown in FIG. 6 includes a first flow control unit 54a in which a first flow control valve 38a, a first open / close control valve 39a, and a first check valve 40a are sequentially connected in series, and a second flow control unit 54a. The second flow rate control valve 38b, the second opening / closing control valve 39b, and the second check valve 40b are sequentially connected in series to the second flow rate control unit 54b in parallel and provided in the second liquid supply pipe 36. .

  The first and second flow control valves 38a and 38b are set in advance at predetermined opening degrees, and the first and second opening / closing control valves 39a and 39b are controlled to be opened and closed by the control device 41. It has become.

  According to the speed control means having such a configuration, when the first opening / closing control valve 39a is opened and the second opening / closing control valve 39b is closed, the rinse liquid having the flow rate set by the first flow control valve 38a is changed to the first flow control valve 39a. Since the second liquid supply pipe 36 flows, the rinse liquid is ejected from the second nozzle 34 at an ejection speed corresponding to the flow rate. Similarly, if the first opening / closing control valve 39a is closed and the second opening / closing control valve 39b is opened, the rinse liquid having the flow rate set by the second flow control valve 38b flows through the second liquid supply pipe 36. The rinse liquid is ejected from the second nozzle 34 at an ejection speed corresponding to the flow rate.

  Further, if the first and second on / off control valves 39a and 39b are opened, the rinse liquid having a flow rate corresponding to the sum of the on / off control valves 39a and 39b flows through the second supply pipe 36. The second nozzle 34 is ejected at an ejection speed according to the above.

  Therefore, according to such a configuration, since the speed of the rinsing liquid ejected from the second nozzle 34 can be changed in three stages, the upper surface of the rectifying cover 45 and the like are reliably rinsed according to the speed change. It is possible.

  In this embodiment, instead of the first and second on-off valves 39a and 39b, the first and second flow control valves 38a and 38b may be controlled by the control device 41, or the on-off valves and Both of the flow control valves may be controlled by the control device 41.

  The substrate processing in the present invention is not limited to the case where the rinsing process is performed after the etching process as described above. Even when the substrate is processed with a processing solution other than the etching solution, the rinsing process is performed after the processing. The present invention can be applied to.

Sectional drawing which shows schematic structure of the spin processing apparatus which shows one embodiment of this invention. Explanatory drawing of a speed control means. Explanatory drawing which shows the relationship between the rotation speed of the turntable in the process process of a board | substrate, and the injection speed of the rinse liquid at the time of a rinse process. (A)-(c) is a figure explaining the change of the injection speed of a rinse liquid, and the injection position of a rinse liquid. Explanatory drawing of the speed control means which shows the 2nd Embodiment of this invention. Explanatory drawing of the speed control means which shows the 3rd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 4 ... Control motor (drive means), 11 ... Rotary table, 18 ... Holding member (holding means), 34 ... 2nd nozzle, 38 ... Flow control valve, 39 ... Open / close control valve, 41 ... Control apparatus.

Claims (5)

A spin processing apparatus for processing while rotating a substrate,
A rotating table,
A plurality of holding means for holding the substrate provided on the turntable;
Drive means for rotating the rotary table;
A first nozzle for supplying a processing liquid toward the lower surface of the substrate held by the turntable;
A second nozzle for supplying a rinsing liquid to the lower surface of the substrate processed by the processing liquid;
Comprising a speed control means for changing the spray speed of the rinse liquid sprayed from the second nozzle ;
The upper surface side of the turntable is covered with a rectifying cover, and a processing liquid sprayed from the first nozzle body and a rinsing liquid sprayed from the second nozzle body are formed in the central portion of the rectifying cover. A spin processing apparatus, wherein a through hole is formed to reach the bottom surface of the substrate held by the rotary table .   The speed control means includes an opening / closing control valve provided in a liquid supply pipe for supplying a rinsing liquid to the second nozzle body, and a control means for controlling opening / closing of the opening / closing control valve. The spin processing apparatus according to 1.   The speed control means includes a flow rate control valve provided in a liquid supply pipe for supplying the rinse liquid to the second nozzle body, and a control means for controlling the flow rate of the rinse liquid flowing through the flow rate control valve. The spin processing apparatus according to claim 1, wherein:   The speed control means is configured to connect an opening / closing control valve and a flow rate control valve in series to form a flow rate control unit, and to supply a rinsing liquid to the second nozzle body with two flow rate control units arranged in parallel. 2. The spin processing apparatus according to claim 1, further comprising a control means for controlling opening / closing of at least an opening / closing control valve among the opening / closing control valve and the flow control valve of each of the flow rate control units. A spin processing method for processing a substrate while rotating the substrate together with a rotary table whose upper surface side is covered with a rectifying cover ,
Supplying the substrate to the turntable;
Rotating the substrate together with the rotary table;
A process of supplying a processing liquid through a through hole formed in the center of the rectifying cover on the lower surface of the substrate rotating together with the rotary table;
Supplying a rinsing liquid to the lower surface of the substrate treated with the processing liquid through the through hole of the rectifying cover, and rinsing processing;
And a step of changing a spraying speed of a rinsing liquid supplied to the lower surface when the lower surface of the substrate is rinsed.

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