JP2001332469A - Developing apparatus and developing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing apparatus and a developing method, enabling a used developer to be re-utilized effectively for developing exposed substrates. SOLUTION: The developing apparatus 90 comprises a developing unit (DEV), having a means for holding exposed substrates, a means for applying the developer on the substrate, and a means for applying a rinsing liquid on the substrate applied with the developer, a recovery unit 80 for recovering the used developer drained from the developing unit (DEV), a developer regenerator 30 for mixing the used developer stored in the recovery unit 80 with a concentration control developer adjusted for a concentration higher than that of the developer, applied to the substrate to produce a developer of a prescribed concentration and a developer feeder 40 for sending the regenerated developer produced in the developer regenerator 30 to the developer applying means in the developing unit (DEV).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing apparatus and a developing method for performing a developing process on a substrate such as a semiconductor wafer which has been exposed.

[0002]

2. Description of the Related Art In a resist coating / developing processing system for a photolithography step in a semiconductor device manufacturing process, a resist coating processing for forming a resist film on the surface of a semiconductor wafer and an exposure of the wafer after the resist coating are performed. After the processing, development processing for developing the wafer is performed. The resist coating processing and the development processing are performed by a resist coating unit and a development processing unit mounted on the system, respectively.

The development processing unit includes, for example, a spin chuck that suction-holds and rotates a semiconductor wafer that has been exposed, a developing solution supply nozzle that supplies a developing solution to the semiconductor wafer on the spin chuck, and a semiconductor solution after the development processing. A rinse nozzle for applying a rinse liquid for cleaning and removing the developer on the wafer, for example, pure water, is provided.

Conventionally, when a developing solution is applied from a developing solution supply nozzle onto a semiconductor wafer, a part of the developing solution discharged from the developing solution supply nozzle flows directly or from the semiconductor wafer and is guided to a drain. Had been discarded. In addition, the developing solution on the semiconductor wafer is shaken off by rotating the semiconductor wafer after the developing process for a predetermined time, and is discarded through the drain.

[0005]

However, of the developer supplied on the semiconductor wafer, the ratio of the developer that actually contributes to the development process is small, while a predetermined amount of the developer is deposited on the semiconductor wafer. Since it is indispensable to perform the developing process uniformly, a large amount of the developing solution has been wasted as a result, and the cost of the developing process has been increased.

Conventionally, when recovering the developer, all of the rinse liquid applied thereafter has also been recovered. In this case, the recovered developer is diluted with a large amount of the rinsing liquid, and there is a problem that the transportation cost for disposal processing increases. In addition, there is a problem that the cost for removing the dirt from the regenerated developer, for example, the installation cost of a filter or the like is relatively high.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and provides a developing apparatus and a developing method capable of efficiently reusing a used developer. With the goal.

[0008]

That is, according to the present invention, there is provided a developing section for applying a developing solution and a rinsing liquid to an exposed substrate to perform a developing process, and a use section discharged from the developing section. And a developer regenerating unit for producing a developer having a predetermined concentration by mixing the used developer and a developer for concentration adjustment adjusted to a high concentration. .

Further, according to the present invention, there are provided means for holding an exposed substrate, a developing solution applying means for applying a developing solution to the substrate, and a rinsing solution applying means for applying a rinsing solution to the substrate coated with the developing solution. A developing unit having a collecting unit that collects used developer discharged from the developing unit, and a higher concentration than the used developing solution stored in the collecting unit and the developing solution applied to the substrate. A developer regenerating unit for producing a developer having a predetermined concentration by mixing the adjusted developer for concentration adjustment, and a regenerating developer produced in the developer regenerating unit being sent to the developer applying means. And a developer supply unit.

Further, according to the present invention, there is provided a method for developing a substrate which has been exposed to light, wherein a developing solution is applied to the substrate, and after a lapse of a predetermined time, the developing solution on the substrate is removed while applying a rinsing solution. A first step of discharging, and a second step of collecting a used developer having a high concentration of the developer discharged from the start of application of the developer in the first step until a lapse of a predetermined time from the start of application of the rinse liquid. And a third step of mixing the used developer recovered in the second step with a concentration adjusting developer adjusted to a higher concentration than the developer applied to the substrate to produce a regenerated developer. And a developing method comprising the steps of:

According to the developing apparatus and the developing method according to the present invention, since the used developing solution having a low rinsing liquid content is efficiently collected, the developing solution is slightly recovered from the developing solution applied to the substrate. By adding a predetermined amount of the concentration-adjusted developing solution, the developing solution having a predetermined concentration used for application to the substrate can be easily regenerated. Since the developer thus regenerated does not contain much of the used rinsing solution as a solvent, the content of impurities such as dust can be made small, and the installation load on the filter and the like can be reduced.

The developing apparatus is divided into a developing section, a collecting section, a developing solution regenerating section, and a developing solution supply section, so that the used developing solution can be collected, stored, regenerated, and regenerated developing solution. Storage and reuse can be performed independently of each other, so that the operation sequence of the development processing apparatus can be made suitable each time according to the work content, and the processing workability is improved. .

[0013]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic plan view showing a resist coating / developing processing system equipped with a developing apparatus of the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a rear view thereof.

This resist coating and developing system 1
Is a cassette station 10 which is a transfer station.
And a processing station 11 having a plurality of processing units
And an interface unit 12 for transferring a semiconductor wafer (wafer) W between an exposure apparatus (not shown) provided adjacent to the processing station 11.

The cassette station 10 carries a plurality of wafers W as objects to be processed, for example, in units of 25 wafers W, into a wafer cassette CR, and loads the wafers W from another system into the resist coating / developing processing system 1 or carries out the resist processing. This is for carrying the wafer W between the wafer cassette CR and the processing station 11, such as carrying out the wafer from the coating / developing processing system 1 to another system.

In the cassette station 10, as shown in FIG.
A plurality of (four in the figure) positioning projections 20a along the direction
The wafer cassettes CR can be placed in a row at the positions of the projections 20a with the respective wafer entrances facing the processing station 11 side. In the wafer cassette CR, the wafers W are arranged in a vertical direction (Z direction). Also, the cassette station 10
A wafer transfer mechanism 21 is provided between the wafer cassette mounting table 20 and the processing station 11.

The wafer transfer mechanism 21 has a wafer transfer arm 21a movable in the cassette arrangement direction (X direction) and the wafer arrangement direction of the wafers W therein (Z direction). One of the wafer cassettes CR can be selectively accessed. In addition, the wafer transfer arm 21a is configured to be rotatable in the θ direction shown in FIG. 1, and includes an alignment unit (ALIM) and an extension unit belonging to a _third processing unit G3 on the processing station 11 side described later. (EXT) can also be accessed.

On the other hand, the processing station 11 is provided with a plurality of processing units for performing a series of steps when performing coating and development on the semiconductor wafer W, and these are arranged at predetermined positions in multiple stages. Thus, the semiconductor wafers W are processed one by one. This processing station 11
Has a wafer transfer path 22a at the center as shown in FIG. 1, in which a main wafer transfer mechanism 22 is provided, and all processing units are arranged around the wafer transfer path 22a. It has become. The plurality of processing units are divided into a plurality of processing units, and each processing unit includes a plurality of processing units arranged in multiple stages along a vertical direction (Z direction).

As shown in FIG. 3, the main wafer transfer mechanism 22 is provided with a wafer transfer device 46 inside a cylindrical support 49 so as to be able to move up and down in the vertical direction (Z direction). The cylindrical support 49 is rotatable by a rotational driving force of a motor (not shown), and accordingly, the wafer transfer device 46 is rotated.
Can be rotated integrally.

The wafer transfer device 46 includes a plurality of holding members 48 that are movable in the front-rear direction of the transfer base 47, and the transfer of the wafer W between the processing units is realized by these holding members 48. .

Further, as shown in FIG.
, Four processing units G₁・ G ₂・ G₃・ G₄But
It is actually arranged around the eha transport path 22a,
Processing unit G₅Can be arranged as needed. This
Among them, the first and second processing units G₁・ G₂Is a cash register
The front of the strike coating / developing processing system 1
The third processing unit G₃Is a cassette
A fourth processing unit G, which is disposed adjacent to the station 10;
₄Is disposed adjacent to the interface section 12.
You. Further, the fifth processing unit G₅Can be placed on the back
ing.

[0022] In the first processing unit _{G 1,} a coater cup (C
In P), a resist coating unit (COT), which is two spinner-type processing units for performing a predetermined process by placing the wafer W on a spin chuck (not shown), and a development processing unit (development for developing a resist pattern) Processing unit, DE
V) are stacked in two stages from the bottom. Similarly, the second processing section G _2, of the resist coating unit (COT) and developing unit (DEV) are two-tiered in order from the bottom as two spinner-type processing units.

[0023] In the third processing unit G ₃ are, as shown in FIG. 3, the oven-type processing units are placed on a mounting table of the wafer W SP (FIG. 1) performs the predetermined processing are multi-tiered . That is, a cooling unit (COL) for performing a cooling process, an adhesion unit (AD) for performing a so-called hydrophobizing process for improving the fixability of a resist, an alignment unit (ALIM) for performing positioning, and carrying in and out of the wafer W. Extension unit (EX
T), four hot plate units (HP) for performing a heating process on the wafer W before and after the exposure process and after the development process are stacked in eight stages from the bottom.
Note that a cooling unit (COL) may be provided instead of the alignment unit (ALIM), and the cooling unit (COL) may have an alignment function.

[0024] The fourth processing unit G ₄ also, the oven-type processing units are multi-tiered. That is, a cooling unit (COL), an extension cooling unit (EXTCOL) which is a wafer loading / unloading section provided with a cooling plate, and an extension unit (EX
T), a cooling unit (COL), and four hot plate units (HP) are stacked in eight stages from the bottom.

[0025] When providing the fifth processing unit G ₅ on the rear side of the main wafer transfer mechanism 22, the processing unit G ₅ of the fifth, laterally relative to the main wafer transfer mechanism 22 along the guide rails 25 It can be moved. Therefore, the fifth processing unit G
Even when ₅ is provided, a space is secured by sliding it along the guide rail 25, so that maintenance work can be easily performed from behind the main wafer transfer mechanism 22.

The interface section 12 is moved in the depth direction (X
Direction) has the same length as the processing station 11. As shown in FIGS. 1 and 2, a portable pickup cassette CR and a stationary buffer cassette BR are arranged in two stages at the front of the interface section 12, and a peripheral exposure device 23 is arranged at the rear. The wafer transfer mechanism 24 is provided at the center.

The wafer transfer mechanism 24 has a wafer transfer arm 24a.
4a moves in the X and Z directions to move both cassettes CR and B
The R and the peripheral exposure device 23 can be accessed. Incidentally, the wafer transfer arm 24a is rotatable in θ direction, the extension unit included in the fourth processing unit G ₄ of the processing station 11 (EXT) and,
Further, it is also possible to access a wafer transfer table (not shown) on the adjacent exposure apparatus side.

In the above-described resist coating / developing processing system 1, first, in the cassette station 10, the wafer transfer arm 21 a of the wafer transfer mechanism 21 stores the unprocessed wafer W on the cassette mounting table 20. Accessing the cassette CR, one wafer W
It is removed and transported to the third processing section _{G 3} of the extension unit (EXT).

The wafer W is loaded from the extension unit (EXT) into the processing station 11 by the wafer transfer device 46 of the main wafer transfer mechanism 22.
Then, the alignment unit (A) of the _third processing unit G3
After alignment by LIM), the wafer is transported to an adhesion processing unit (AD), where a hydrophobizing process (HMDS process) for improving the fixability of the resist is performed. Since this process involves heating, the wafer W is then
The cooling unit (CO)
L) and cooled.

After the adhesion process is completed, the wafer W cooled by the cooling unit (COL) is subsequently transferred by the wafer transfer device 46 to the resist coating unit (COT), where a coating film is formed. After the completion of the coating process, the wafer W is transferred to the third or fourth processing unit G ₃
· G is prebaked processing with either a hot plate unit of ₄ (HP), it is then cooled in one of the cooling units (COL).

The cooled wafer W is supplied to a third processing unit G ₃
Is conveyed to the alignment unit (ALIM), where it is aligned, it is conveyed to the interface section 12 via the fourth processing unit G ₄ extension units (EXT).

In the interface section 12, peripheral exposure is performed by a peripheral exposure device 23 to remove excess resist. Thereafter, the wafer W is exposed to a predetermined light by an exposure device (not shown) provided adjacent to the interface section 12. An exposure process is performed on the resist film of the wafer W according to the pattern.

The wafer W after the exposure is returned to the interface section 12 again, and the extension unit (EX) belonging to the fourth processing section G ₄ is moved by the wafer transfer mechanism 24.
T). The wafer W is transferred to one of the hot plate units (H
P) to be subjected to post-exposure bake processing, and then cooled by a cooling unit (COL).

Thereafter, the wafer W is transferred to the development processing unit (D
(EV), where the exposure pattern is developed. After the development is completed, the wafer W is transferred to one of the hot plate units (HP) and subjected to post-baking, and then cooled by the cooling unit (COL). After such a series of processing is completed, and returned to the cassette station 10 through the third processing unit G ₃ of the extension unit (EXT), is inserted into one of the wafer cassettes CR.

Next, the development processing unit (DE
V) will be described in detail. 4 and 5 are a schematic sectional view and a schematic plan view showing the configuration of the developing unit (DEV).

An annular cup CP is disposed at the center of the developing unit (DEV), and a spin chuck 52 is disposed inside the cup CP. The spin chuck 52 is rotationally driven by a drive motor 54 in a state where the wafer W is fixedly held by vacuum suction. The drive motor 54 is disposed so as to be able to move up and down in the opening of the unit bottom plate 50, and is connected to a lift drive means 60 and a lift guide means 62, for example, made of an air cylinder via a cap-like flange member 58 made of, for example, aluminum. I have. A cylindrical cooling jacket 64 made of, for example, stainless steel (SUS) is attached to the side surface of the drive motor 54, and the flange member 58 is attached so as to cover the upper half of the cooling jacket 64.

During the application of the developing solution, the lower end of the flange member 58 is in close contact with the unit bottom plate 50 near the outer periphery of the opening of the unit bottom plate 50, thereby sealing the inside of the unit.
When the transfer of the wafer W is performed between the spin chuck 52 and the main wafer transfer mechanism 22, the lifting drive mechanism 60
Lifts the drive motor 54 or the spin chuck 52 upward so that the lower end of the flange member 58 floats from the unit bottom plate 50. Note that a window 70 through which the holding member 48 enters is formed in the casing of the development processing unit (DEV).

The developing solution supply nozzle 86 for supplying the developing solution to the surface of the wafer W has a long shape and is disposed with its longitudinal direction being horizontal, and a developing solution supply section 89 is provided through a developing solution supply pipe 88. It is connected to the. This developer supply nozzle 8
6 is detachably attached to the tip of the nozzle scan arm 92. The nozzle scan arm 92 is attached to the upper end of a vertical support member 96 that can move horizontally on a guide rail 94 laid on the unit bottom plate 50 in one direction (Y direction). It moves in the Y direction integrally with the vertical support member 96. The developer supply nozzle 86 can be moved vertically (Z direction) by a Z-axis drive mechanism 112.

As a method of applying the developer, the developer supply nozzle 86 is driven by the Y-axis driving mechanism 111 while the developer is discharged from the developer supply nozzle 86 in a strip shape onto the wafer W.
Is moved along the guide rail 94 so as to scan on the wafer W, or is moved to a position overlapping the diameter of the wafer W above the wafer W, for example, a position shown in FIG. And a method of rotating the wafer W at least １ ／ while discharging the developing solution onto the wafer W.

After the developer is applied, the developer supply nozzle 86 waits in a nozzle standby unit 115 (FIG. 5). The nozzle standby unit 115 has a nozzle cleaning mechanism (a nozzle cleaning mechanism) for cleaning the nozzle 86. A nozzle bath 120 is provided.

The developing unit (DEV) has a rinsing nozzle 102 for discharging and applying a rinsing liquid (cleaning liquid), and the rinsing liquid is supplied from the rinsing liquid supply unit 100 to the rinsing nozzle 102. You. The solvent of the developing solution is suitably used as the rinsing solution. In the following embodiments, it is assumed that pure water is used as the developing solution and pure water is used as the rinsing solution.

The rinse nozzle 102 has a guide rail 94
It is attached to the tip of a nozzle scan arm 104 movably provided in the Y direction, and is moved onto the wafer W after completion of the developing process with the developing solution, and is used to discharge the cleaning solution to the wafer W. . The shape of the rinsing nozzle 102 is not limited, and for example, a pipe-shaped straight nozzle can be used. Unnecessary developer and used rinse are discharged from the drain 69.

The operation of the drive system of the development processing unit (DEV) is controlled by the control unit 110. That is, the drive motor 54, the Y-axis drive mechanism 111 and the Z-axis drive mechanism 112, the developer supply unit 89, and the rinsing liquid supply unit 1
00 and the like are driven and controlled by a command from the control unit 110.

Next, the operation of the developing process in the developing unit (DEV) configured as described above will be described. The wafer W on which a predetermined pattern has been exposed, subjected to the post-exposure bake processing and the cooling processing, is transferred to a position directly above the cup CP by the holding member 48 of the main wafer transfer mechanism 22, and is raised by the lifting drive mechanism 60. Is adsorbed in vacuum.

Next, the developer supply nozzle 86 moves the wafer W
The developer supply nozzle 86 is moved upward by the Y-axis driving mechanism 111 while the developer is supplied in a strip shape from the developer supply nozzle 86.
To the position above the other end in the Y direction. Subsequently, the developer supply nozzle 86 is driven by the Y-axis driving mechanism 111 while the developer is discharged in a belt shape from the developer supply nozzle 86.
Is moved to a position above the first end in the Y direction. After the application of the developing solution is completed, the developing solution supply nozzle 86 is moved to the nozzle standby unit 115 and stored therein.

As described above, the developer supply nozzle 8
6 are arranged so as to coincide with the diameter direction of the wafer W,
The developer may be applied on the wafer W by rotating the wafer W a predetermined number of times.

As described above, the developer is applied by performing the reciprocating motion of the developer supply nozzle 86 a predetermined number of times. When the developer supply nozzle 86 is moved in the horizontal direction (Y direction), Since the movement trajectory of the developer supply nozzle 86 draws a quadrangle, the wafer W is circular, so that a part of the belt-like developer discharged from the developer supply nozzle 86 is pooled on the wafer W. Instead, the waste liquid is directly discharged and discharged from the drain 69. In addition, it is difficult to uniformly supply the developing solution to the wafer W in a short time without dripping from the wafer W regardless of the method of supplying the developing solution. In this way, the developer dripping from the wafer W also becomes a waste liquid, and the drain 69
Is discharged from

As described above, when the developing solution is filled on the wafer W and the developing solution paddle is formed and is kept stationary for a predetermined time, the developing process proceeds by natural convection of the developing solution during this period. After the lapse of the predetermined time, the rinsing nozzle 102 is moved above the wafer W, and while the rinsing liquid (cleaning liquid) is discharged from the rinsing nozzle 102, the spin chuck 52 is rotated and held for a predetermined time. Shake off developer with rinse. The developer and rinsing liquid thus shaken off are also discharged from the drain 69 as waste liquid.

In such a series of development processing, in the present invention, a waste liquid (used developer) discharged from the development processing unit (DEV) is collected and reused. FIG. 6 shows a developing apparatus 9 including a developing unit (DEV).
FIG. 1 is an explanatory diagram showing the overall configuration of an embodiment. The development processing device 90 includes a development processing unit (DEV),
0, a developing solution regenerating unit 30, and a developing solution supply unit 40.

The collection section 80 is provided with a collection tank 81, and the collection tank 81 is provided with a development processing unit (DEV).
The used developer discharged from the drain 69 is collected and temporarily stored. Without providing the recovery unit 80, it is possible to employ a configuration in which the used developer discharged from the development processing unit (DEV) directly flows into the developer regeneration unit 30. The used developing solution flows into the developing solution regenerating section 30 in accordance with the progress of the developing process of the wafer W in the processing unit (DEV).

In this case, the amount of the used developing solution stored in the developing solution regenerating section 30 is not constant, which causes a problem that it is difficult to produce the developing solution during the developing process of the wafer W. Conversely, when a regeneration process for adjusting the concentration of the used developer is performed in the developer regeneration unit 30, a new developer regeneration unit 3 is used.
It is not preferable to let the used developer flow into 0,
In such a case, it becomes necessary to discard the used developer, and there arises a problem that effective recycling of the developer cannot be achieved.

On the other hand, since the amount of the developing solution used for developing one wafer W is not large, the used developing solution used for processing a plurality of wafers W is collected in the collecting tank 81, and a predetermined amount is collected. After being stored, the developer regenerating section 30
When a predetermined amount of used developer is supplied to the developer, batch processing of density adjustment in the developer regenerating unit 30 becomes easy. Further, the used developer can be regenerated in the developer regenerating section 30 independently of the development processing of the wafer W in the development processing unit (DEV). When the developing process of the wafer W is performed simultaneously with the regenerating process of the used developing solution, the used developing solution discharged from the developing unit (DEV) is collected in the collection tank 81, so that the used developing device is used. It is possible to increase the liquid recycling efficiency.

Development processing unit (DEV) and collection unit 80
A switching valve 83 is provided in the pipe between
The developing solution and the rinsing solution flowing out from the drain 69 of the developing unit (DEV) are collected by the collecting section 80 or the drain 84.
It can be switched so that it flows to one side. As described later, in the present invention, for the purpose of efficiently regenerating the used developer, only the used developer having a large content of the developer and a small content of the rinse solution is collected. That is, in the development processing of the wafer W,
The used developer having a low rinsing liquid content from the start of the application of the rinsing liquid to the elapse of a predetermined time is collected by the collecting unit 80.
And the discharged liquid mainly containing a rinsing liquid and having a small developer content flowing out from the drain 69 is drained from the drain 8.
The switching valve 83 is operated so as to be guided to No. 4 and discarded.

The recovery tank 81 is provided with a drainage mechanism (drain) 82 for preventing overflow. A plurality of the collection tanks 81 may be provided,
When one recovery tank overflows, the recovery liquid flowing out from the drain may be sent to another recovery tank.

The developer regenerating section 30 includes a processing tank 31 and
It has a concentration adjusting developer supply device 32 for supplying a concentration adjusting developer adjusted to a higher concentration than the developer applied to the wafer W, and a pure water supply device 33 for supplying pure water. A diffusion container 34 made of a porous material is provided in the processing tank 31, and an inner chamber 34 a is provided in the diffusion container 34.
However, outside chambers 34b are respectively formed outside the diffusion container 34 and inside the processing tank. The material of the porous body used for the diffusion container 34 is not limited, and a porous metal, a porous ceramic, a porous resin, or the like is used. In addition, as the diffusion container 34, various containers made of metal, resin, ceramic, or the like having a plurality of holes formed therein can be used.

The liquid is sent from the collecting section 80 to the developing solution regenerating section 30 by operating a pump 35 provided in a pipe between the collecting section 80 and the developing solution regenerating section 30 and by opening and closing a valve 36. The used developer is supplied to the outer chamber 34b. It is also preferable to dispose a filter 37 at an arbitrary position in the middle of the pipe between the collecting section 80 and the developer regenerating section 30 to remove impurities in the used developer.

The developer for concentration adjustment is introduced into the inner chamber 34a from the developer supply device 32 for concentration adjustment, passes through the porous wall surface of the diffusion container 34, flows out to the outer chamber 34b, and mixes with the used developer. Is done. At this time, the outflow pressure when the concentration adjusting developer is sent from the inner chamber 34a to the outer chamber 34b is adjusted, and natural convection is generated in the used developer by the outflow force of the concentration adjusting developer to perform self-stirring. By doing so, it is possible to uniformly mix the developer for concentration adjustment and the used developer. In this case, a separate stirring mechanism is not particularly required, but a stirring function can be separately provided.

The pure water supplied from the pure water supply device 33 is
Used for various density adjustment processes. For example, by mixing a concentration adjusting developer and pure water, a new developer (new solution) having a concentration to be applied to the wafer W can be manufactured. If the developer is regenerated many times, the produced developer will contain a lot of impurities such as dust and may become unsuitable for use. By replenishing the solution, it becomes possible to maintain the development processing characteristics at a certain level. Also, pure water is
When the concentration of the regenerated developer adjusted using the used developer and the developer for concentration adjustment is high, it can be used for fine adjustment of the concentration.

The processing tank 31 is provided with a water level sensor 39 and a drain 38. The water level sensor 39 monitors the amount of the processing liquid in the processing tank 31, and when the processing liquid reaches a certain level or more, the water is discharged from the drain 38. You can do it. Of course, it is needless to say that setting the processing conditions so as not to discharge the developing solution from the drain 38 is preferable from the viewpoint of increasing the recycling rate of the developing solution.

As described above, the developer that is no longer suitable for use can be discarded from the drain 38. An exhaust pipe 28 provided with a valve 29 is provided above the processing tank 31 to enable the pressure in the processing tank 31 to be adjusted. Discharge is easy.

The processing tank 31 is provided with a concentration sensor 41 for monitoring and monitoring the developer concentration in the outer chamber 34b. Based on the display value of the density sensor 41, it is possible to supply an appropriate amount of a developer for concentration adjustment or pure water by an appropriate amount to set the concentration of the regenerated developer to a predetermined value. In addition,
Such production of the regenerated developer and fine adjustment of the concentration can be designed to be automatically performed if the concentration and amount of the used developer and the concentration of the concentration adjusting developer are clear.

The developing solution supply section 40 has a role of sending the regenerated developing solution or the new solution produced in the developing solution regenerating section 30 to the development processing unit (DEV). The developing solution supply unit 40 includes a tank 76 for storing the regenerated developing solution sent from the developing solution regenerating unit 30, a mechanism for sending the regenerating developing solution to the developing unit (DEV), a liquid sending pump 77, and the like. Is provided. If necessary, a storage tank for a new developing solution can be provided independently of the developing solution regenerating section 30.

It is also possible to directly feed the developer from the developer regenerating unit 30 to the development processing unit (DEV) without providing the developer replenishing unit 40. However, there is a problem that it is difficult to produce a recycled developer because the amount of the processing solution such as a used developer and a recycled developer is not constant.

The liquid is sent from the developing solution regenerating section 30 to the developing solution supply section 40 by operating the pump 42 and opening and closing the opening / closing valve 44, and is connected to a pipe connecting the developing solution regenerating section 30 and the developing solution supply section 40. It is preferable that a filter 43 is provided to remove impurities such as dust in the regenerating developer, and a pressure sensor 45 is provided to detect a pressure loss in the piping to monitor the clogged state of the filter 43. Is also preferred.

A degassing mechanism 71 is provided in the liquid supply path from the developer supply unit 40 to the development processing unit (DEV). This removes bubbles in the supplied developer and removes the wafer W. This prevents the occurrence of bubbles on the surface of the wafer W and uneven development. Further, a developer temperature control mechanism 74 is provided in this liquid supply path,
The developing unit (D) is adjusted to an appropriate temperature so that the developing solution can exhibit a predetermined developing performance.
EV).

A liquid supply path from the developer supply section 40 to the development processing unit (DEV) further includes a flow sensor 72.
Is provided, and by controlling the liquid feed pump 77 in response to the signal of the flow rate sensor 72, the flow rate of the developer to be fed is controlled. In addition, the filter 73 removes impurities in the developing solution to such an extent that the developing solution can be finally applied to the wafer W.

Next, a description will be given of a mode of recycling the developer in the developing apparatus 90 described above. As described in detail above, after the exposed wafer W is fixed on the spin chuck 52, a predetermined amount of the developing solution is applied on the wafer W and is held for a predetermined time. After the predetermined time has elapsed, the developing solution and the rinsing liquid are shaken off from the wafer W by rotating the wafer W while applying the rinsing liquid to the wafer W. Hereinafter, this step is referred to as a first step.

FIG. 7 shows a change in the concentration of the developer in the used developer generated in the first step. From a developer coating start time t _1, the spent developer generated between the developer coating end time t ₂ without being discharged from the developer supply nozzle 86 is puddled on the wafer W, directly to the draining Since the developer has become as described above, the time period t _{1 to} t
The developer concentration of the used developer generated during the period ₂ is constant.

[0,069] subsequent time the developing solution on the wafer W is held, that is, between the developer coating end time t ₂ to the rinsing liquid coating start time t ₃ is being developed, usually, used developer solution Does not leak. Thus in Figure 7, the concentration of the developer in the drainage during this time period t ₂ ~t ₃ are not shown.

[0070] Then, during reaches the cleaning end time t ₄ from the rinsing liquid coating start time t _3, by rotating the wafer W while applying a rinse solution, since shaken off developing solution and rinsing liquid together, resulting developer concentration in the spent developer, gradually and it decreases as the cleaning time, the cleaning end time t _4, the developer concentration in the spent developer be regarded as almost 0% Can be.

In the present embodiment, among the used developing solutions thus generated in the first step, only those having a high developing solution content are collected, and the used developing solutions having a low developing solution content are discarded. . For example, the region P in FIG.
_The waste liquid indicated by ₁ , that is, all the used developer generated by the application of the developer is collected, and the used developer generated during the cleaning process is a time after a predetermined time has elapsed from the rinsing liquid application start time t _3. area _{P 2} that occurs in up to t ₅
Spent developer corresponding to the portion shown in is recovered, used developer solution indicated by a region P ₃ that occurs after a predetermined time t ₅ elapses and be discarded without recovering. Hereinafter, such a used developer recovery step is referred to as a second step.

The collection and disposal of the used developer in the second step is performed by operating the switching valve 83 provided between the developing unit (DEV) and the collection unit 80. That is, in the developer coating start time _{t 1,}
Switching valve 83, the used developer is set to flow into the collection tank 81, the used developer corresponding to the region P ₁ is thus flows to a collection tank 81, is stored. In this state, when it becomes a predetermined time t _5,
Switching the switching valve 83 to the drain 84 side and the used developer in the region P ₂ is recovered to a recovery tank 81, mainly consisting of rinsing solution used developer solution region P ₃ is a flow into the drain 84 Is discarded.

Incidentally, actually, the development processing unit (DE
The time Δt for the drainage to flow before the drainage generated in V) reaches the switching valve 83 through the drain 69.
Time lag occurs. Therefore, in order to recover the drainage indicated by a region P ₂ is switched from the recovery tank 81 side of the switching valve 83 to the drain 84 side, the predetermined time t
It is preferable to perform from ₅ at time t _6, which was delayed about this Δt. From the drain 84 side of the switching valve 83 to the collection tank 8
The switching to the first side may be performed at any timing after the drainage containing a large amount of the rinsing liquid is hardly discharged and before the developing solution for the next process flows out as the drainage. For example, it can be performed when the wafer W to be processed next is fixed to the spin chuck.

[0074] In the second step, has been for the spent developer collected in the collection tank 81, the used developer solution corresponding to the region P _1, of the rinsing liquid when a developing process is performed on the recovered previously Partly remains in the cup (CP), and considering that the used developer is diluted by the remaining rinse, the amount of the rinse is not large. It has about the same concentration as the developer used. On the other hand, the used developer corresponding to the region P _2, since that contains a certain amount of rinsing liquid,
As a result, the concentration of the used developer collected in the collection tank 81 is lower than the concentration of the developer applied to the wafer W.

Since the amount of used developer recovered in the recovery tank 81 by processing one wafer W is not large, it is preferable that the processing of a plurality of wafers W is completed and After the used amount of the developer is stored in the recovery tank 81, it is sent to the outer chamber 34 b of the processing tank 31 of the developer regenerating unit 30. In the developer regenerating section 30, the concentration of the used developer fed by the concentration sensor 41 is confirmed, and a predetermined amount of the developer for concentration adjustment is supplied from the concentration adjusting developer supply device 32 to the inner chamber of the diffusion container 34. 34a
By uniformly mixing the used developer and the developer for concentration adjustment in the processing tank 31, a developer (regenerated developer) adjusted to a predetermined concentration that can be applied to the wafer W is manufactured. You. This step is referred to as a third step.

For example, for one wafer W, the amount of the developing solution supplied to the wafer W by the developing unit (DEV) is 100 ml, and the amount of the developing solution is in the areas P ₁ and P ₂ shown in FIG. The corresponding spent developer is 80
Suppose that ml is collected. The concentration of the developer applied to the wafer W is 2%, and the collected used developer 80 ml
If 16 ml corresponding to 20% is the rinse solution, the concentration of the used developer is 1.6%. Therefore, 100 ml of a 2% concentration developer applied to the wafer W
In order to regenerate the developer, the collected developer 80 m
1 with a developer for concentration adjustment adjusted to a concentration of 3.6%,
What is necessary is just to add 20 ml. In this way, a developing solution used for developing a new wafer W is manufactured from a developing solution used for developing a single wafer W.

[0077] On the other hand, for example, consider a case where the recovered until the spent developer corresponding to the region P ₃ shown in FIG. As in the previous example, for one wafer W, the amount of the developer supplied to the wafer W by the development processing unit (DEV) is 10
It is 0 ml, of which, the used developer corresponding to the region _P 1 _{· P} 2 _{· P 3} shown in FIG. 7 described above, 150
Suppose that ml is collected. In this case, even if a solute is added to the collected used developer, a minimum of 150 ml of the regenerated developer is produced, and a new one of the developer used for developing one wafer W is used. A developer corresponding to the above processing amount is produced.

When the production of such a regenerated developer is repeated, more developer than necessary is produced, and as a result, a large amount of the developer needs to be discarded. In addition, the amount of solvent used increases, which causes an increase in cost. Furthermore, since the used rinsing liquid is used as a solvent, the content of impurities such as dust increases, and various problems occur, such as the time and cost required for the subsequent processing such as filtration and equipment. . Therefore, it is preferable that the amount of the used developer collected in the second step is suppressed to an amount that does not exceed the amount of the developer required for the development processing of one wafer W.

If the switching timing of the switching valve 83 is kept constant in accordance with the development processing in the development processing unit (DEV), the concentration of the used developer recovered in the recovery tank 81 may vary greatly. There is no. However, when the concentration of the used developer slightly changes for some reason, it is necessary to perform final concentration adjustment.

Accordingly, the pure water supplied from the pure water supply device 33 is used for final concentration adjustment for diluting the regenerated developer when the concentration of the regenerated developer once produced is higher than a predetermined value. Can be. On the other hand, when the concentration of the regenerated developer once manufactured is lower than the predetermined value, the concentration of the regenerated developer can be set to the predetermined value by adding a predetermined amount of the concentration adjusting developer.

By mixing a predetermined amount of pure water and a concentration adjusting developer, a developer having a predetermined concentration that can be applied to the wafer W can be manufactured. The new liquid produced in this way is discarded when the amount of impurities such as dust contained in the used liquid increases due to repeated regeneration of the liquid developer and becomes unsuitable for use. Then, it can be used to replenish the shortfall due to the disposal. Further, even if maintenance of the recovery unit 80 is required during the development process, or a failure of the pump 35 between the recovery unit 80 and the developer regenerating unit 30 occurs, the developer is manufactured and the development processing unit is manufactured. (DEV).

The production of the regenerating developer in the regenerating unit 30 is automatically performed if the amount and concentration of the used developer sent to the regenerating unit 30 and the concentration of the developing solution for concentration adjustment are known. By calculating the amount of the developer for concentration adjustment, a predetermined amount of a regenerated developer can be produced.

The regenerated developing solution produced by the developing solution regenerating section 30 is used as it is by the filters 43 and 73 and the developing solution temperature control mechanism 7.
4, it is also possible to send the solution to the developing unit (DEV), but in that case, the amount of the developing solution in the processing tank 31 is not constant, and it becomes difficult to adjust the concentration of the developing solution. Thus, in the present embodiment, the regenerated developer manufactured by the developer regenerating unit 30 is sent to the developer supplying unit 40 and stored. Then, a predetermined amount of the developer is sent from the developer supply unit 40 to the development processing unit (DEV) as necessary. That is, the produced regenerated developer is used for the development process (first step) of a new wafer W.

As described above, in the present embodiment, the second step needs to be performed in parallel with the first step, but the third step is performed at an arbitrary time in parallel with or independently of the first step. be able to. Therefore, maintenance of the development processing unit (DEV), the recovery unit 80, the developer regeneration unit 30, and the developer supply unit 40 can be performed even when other units are operating.

The present invention is not limited to the above embodiment, and various modifications are possible. For example, a predetermined amount of the developer for concentration adjustment is stored in the processing tank in advance, and the used developer is sent to the developer while stirring the developer for concentration adjustment. At the point when the measured value of the density sensor drops to a predetermined concentration and the regenerated developer is manufactured, the feeding of the used developer is stopped, and the manufactured regenerated developer is sent to the developer supply unit. It is also possible to take.

In the above description, the development processing unit incorporated in the resist coating / development processing system for semiconductor wafers has been described as an example. However, the development processing apparatus may be used alone, The present invention can also be applied to a development processing apparatus for a substrate to be processed other than a wafer, for example, an LCD substrate.

[0087]

As described above, according to the present invention, in recovering a developer, a used developer having a low content of a rinse solution applied thereafter and a high developer concentration is recovered and regenerated. Therefore, it is possible to efficiently regenerate the developer with less contamination. As a result, it is possible to reduce the amount of the developing solution used and to reduce the development processing cost.
In addition, by dividing the developing device into the developing unit (developing unit), the recovery unit, the developing solution regenerating unit, and the developing solution supply unit, the operation and maintenance of each unit can be performed independently. It becomes possible, and workability is improved. In the developer regenerating section, by using a diffusion container made of a porous body or a diffusion formed with a plurality of holes, the used developer and the concentration adjusting developer can be used without providing a separate stirring means. Can be uniformly mixed, so that a compact device having a simple structure can be obtained. Further, in the developer regenerating section, it is possible to produce a new developer from the concentration adjusting developer and pure water, and the repetition of the regenerating of the developer increases the impurities and the like in the regenerated developer. Even if it becomes unsuitable for use, the developer can be easily manufactured and replenished, and there is no need to separately provide a developer supply tank, so that the apparatus can be downsized.

[Brief description of the drawings]

FIG. 1 is a plan view showing an overall configuration of a semiconductor wafer resist coating / developing system incorporating a developing apparatus according to an embodiment of the present invention.

FIG. 2 is a front view showing the overall configuration of a semiconductor wafer resist coating and developing processing system in which the developing apparatus according to the embodiment of the present invention is incorporated.

FIG. 3 is a rear view showing the overall configuration of a semiconductor wafer resist coating / developing processing system incorporating the developing apparatus according to the embodiment of the present invention;

FIG. 4 is a cross-sectional view showing one embodiment of a developing unit used in the developing apparatus of the present invention.

FIG. 5 is a plan view showing the developing unit shown in FIG. 4;

FIG. 6 is an explanatory view showing the overall configuration of the developing apparatus of the present invention.

FIG. 7 is an explanatory diagram showing a change in developer concentration in a used developer discharged from a development processing unit.

[Explanation of symbols]

 30; developer regenerating unit 31; processing tank 32; concentration adjusting developer supply unit 33; pure water supply unit 34; diffusion vessel 38; drain 39; water level sensor 40; developer supply unit 41; concentration sensor 69; Degassing device 73; filter 74; developer temperature control mechanism 80; collection section 81; collection tank 83; switching valve 82; drainage mechanism (drain) 84; drain 90; development processing device DEV; Wafer (substrate)

Claims (19)

[Claims] 1. A developing section for applying a developing solution and a rinsing liquid to an exposed substrate to perform a developing process, and a used developer discharged from the developing section and a concentration adjustment adjusted to a high concentration. And a developer regenerating unit for producing a developer having a predetermined concentration by mixing the developer with the developer. 2. A development processing unit comprising: means for holding a substrate that has been subjected to exposure processing; developing solution applying means for applying a developing solution to the substrate; and rinsing solution applying means for applying a rinsing solution to the substrate on which the developing solution has been applied. A collection unit that collects used developer discharged from the development processing unit; and a concentration adjustment that is adjusted to be higher than the used developer stored in the collection unit and the developer applied to the substrate. A developing solution regenerating unit that mixes the developing solution with the developing solution to produce a developing solution having a predetermined concentration; and a developing solution supply unit that sends the regenerating developing solution manufactured in the developing solution regenerating unit to the developing solution applying unit. A development processing device comprising: 3. The developer supply section has a deaeration mechanism and a developer temperature control mechanism, and the regenerated developer is sent to the developer application means after deaeration and temperature adjustment are performed. 3. The development processing apparatus according to claim 2, wherein: 4. The collection unit according to claim 2, wherein the collection unit has a collection tank provided with a drainage mechanism, and overflow of the collection tank is prevented by the drainage mechanism. Development processing equipment. 5. The switching valve according to claim 2, wherein a switching valve is provided so that the used developer discharged from the developing section is sent to one of the collecting section and the drain. The developing device according to claim 4. 6. An opening / closing unit between the development processing unit and the collection unit, between the collection unit and the developer regeneration unit, and between the developer regeneration unit and the developer supply unit. 3. A valve is provided, wherein the on-off valve is opened and closed in accordance with the operation timing of each section, and a predetermined amount of the used developer or the regenerated developer is supplied. 6. The development processing apparatus according to any one of 5. 7. The developer regenerating section has a solvent supply device, and adjusts the concentration of the regenerated developer using a solvent supplied from the solvent supply device, or mixes the regenerated developer with the concentration adjusting developer. The developing device according to any one of claims 1 to 6, wherein a new liquid is produced. 8. The developing solution regenerating section has a concentration adjusting tank provided with a concentration sensor. The concentration sensor monitors the concentrations of the used developing solution and the regenerating developing solution, and adjusts the concentration of the regenerating developing solution. The developing device according to claim 1, wherein the developing device is adjusted to a predetermined value. 9. The developing solution regenerating section has a concentration adjusting tank, and the concentration adjusting tank is configured to prevent overflow of the concentration adjusting tank or to discard unnecessary used developer. The developing device according to any one of claims 1 to 8, wherein the water tank is provided with a water level sensor and a drainage mechanism. 10. The developer regenerating section has a concentration adjusting tank, and a container made of a porous body or a container having a plurality of holes formed therein is disposed in the concentration adjusting tank. An outer chamber is formed, and the concentration adjusting developer supplied to the inner chamber diffuses into the used developer supplied to the outer chamber through the porous body or the hole, The developing apparatus according to claim 1, wherein the regenerating developer is manufactured. 11. A method for developing a substrate that has been exposed to light, comprising: applying a developing solution to the substrate; removing a developing solution from the substrate while applying a rinsing solution after a lapse of a predetermined time; A second step of collecting a used developer having a high developer concentration discharged from the start of the application of the developer in the first step to a lapse of a predetermined time from the start of the application of the rinse liquid in the first step; A third step of mixing the used developer recovered in the two steps with a concentration adjusting developer adjusted to a higher concentration than the developer applied to the substrate to produce a regenerated developer. A developing method characterized by the following. 12. The used developer recovered in the second step is temporarily stored in a recovery tank, and the processing in the third step is optionally performed using the used developer stored in the recovery tank. 12. The method according to claim 11, wherein the step is performed on time.
The development processing method described in 1. above. 13. The method according to claim 12, wherein in the second step, the discharged liquid mainly composed of the rinse liquid discharged after the used developer having a small content of the rinse liquid is guided to a drain and discarded. The development processing method according to claim 11 or 12. 14. In the second step, the concentration of the collected used developer is stopped by stopping the collection of the used developer discharged in the first step after a lapse of a predetermined time from the start of the application of the rinsing liquid. The developing method according to any one of claims 11 to 13, wherein the developing method is maintained at a constant high level. 15. The method according to claim 11, wherein in the second step, the amount of used developer collected on one substrate is smaller than the amount of developer applied on one substrate. The development processing method according to claim 14. 16. The developing method according to claim 11, wherein the concentration of the regenerated developer is adjusted by supplying a solvent of the developer. 17. The developing method according to claim 16, wherein in the third step, a new developing solution is adjusted by a predetermined amount by mixing the concentration adjusting developing solution and the solvent, and replenished. Processing method. 18. The method according to claim 11, wherein the regenerated developer is temporarily stored in a developer supply unit, and the stored regenerated developer is subjected to an arbitrary development process.
The developing method according to any one of the above. 19. The method according to claim 11, wherein the second step is performed in parallel with the first step, and the third step is performed at an arbitrary time in parallel with or independently of the first step.
The development processing method according to claim 1.