JP4073354B2 - Application processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coating processing apparatus for coating a coating liquid such as a resist on a substrate such as a semiconductor wafer. In place Related.
[0002]
[Prior art]
For example, in the manufacturing process of a semiconductor device, a resist solution is formed on the surface of a semiconductor wafer (hereinafter simply referred to as “wafer”) to form a resist film, and the wafer after resist application corresponds to a predetermined pattern. Then, after performing the exposure process, a resist pattern is formed as a mask for forming a predetermined pattern by a so-called photolithography technique in which the exposure pattern formed on the resist film of the wafer is developed. In the resist coating process among the above steps, a spin coating method is frequently used as a method for uniformly coating a resist solution on the wafer surface.
[0003]
That is, while rotating the wafer while the wafer is fixed and held by vacuum chucking with a spin chuck, a resist solution is dropped onto the center of the wafer surface from a resist nozzle disposed above the wafer, and the wafer is moved radially outward by centrifugal force. After spreading the resist film over the entire surface of the wafer, stop dripping the resist solution, continue rotating the wafer, shake off excess resist solution on the wafer surface, adjust the film thickness, and dry. Is.
[0004]
By the way, in such a spin coating apparatus, a spin chuck on which a wafer is held for the purpose of preventing a fine droplet (mist) of a resist solution generated by the rotation of the wafer from reattaching to the substrate. Is housed in a cup having an open top, and is exhausted from the bottom of the cup via an exhaust duct to form a downflow air around the wafer and eliminate mist (for example, Patent Document 1). ).
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 5-121308
[0006]
[Problems to be solved by the invention]
For this reason, the mist generated in the cup adheres to and accumulates in the exhaust duct along the exhaust flow. However, the mist accumulated in the exhaust duct peels off and flows backward in the exhaust path, and the wafer in the cup. As a foreign matter (particles), the coating film has defects.
[0007]
Also, mist accumulation in the exhaust duct increases the flow resistance of the exhaust flow path, fluctuates the exhaust characteristics, destabilizes the downdraft state around the wafer, and causes variations in resist coating film thickness. There is also a problem that causes it.
[0008]
As a countermeasure against such problems, it is conceivable to disassemble the exhaust duct and remove the mist accumulated inside, but it takes a long time to disassemble, clean, and assemble the exhaust duct, and the operation of the equipment A new problem of a decrease in rate and an increase in the number of man-hours for maintenance work occurs.
[0009]
The present invention has been made in view of such circumstances, and is a coating processing apparatus capable of improving the operating rate of the coating processing apparatus and reducing the maintenance man-hours. Place The purpose is to provide.
[0010]
In addition, the present invention reduces the coating film thickness due to the reduction in coating film defects due to the adhesion of foreign matters derived from the exhaust duct and the variation in the exhaust characteristics without causing a decrease in the operating rate of the coating processing apparatus and an increase in the maintenance management man-hour. Application processing equipment that can prevent variation Place The purpose is to provide.
[0011]
In order to solve the above problems, the present invention One point of view Then, a coating processing apparatus for forming a coating film by supplying a coating solution to a substrate to be processed, the substrate holding member rotating the substrate to be processed substantially horizontally and the substrate held by the substrate holding member. A coating liquid discharge nozzle for discharging the coating liquid onto the processing substrate; a storage container for storing the substrate to be processed held by the substrate holding member; an exhaust duct for exhausting the inside of the storage container; and the exhaust A duct cleaning mechanism that cleans the inside of the duct by spraying a solvent A duct drain case provided in the exhaust duct and into which the solvent sprayed into the exhaust duct flows, and the exhaust duct communicates with the bottom of the storage container, and the exhaust A first inclined angle including a branch duct connected to the pipe and a collective duct connected to the branch duct, wherein a bottom portion of the branch duct falls from a connection end side to the exhaust pipe to a connection end side to the collective duct And the mist adhesion area is relatively low, and the solvent sprayed inside the branch duct gathers in the mist adhesion area due to the inclination of the second inclination angle. And is configured to flow into the duct drain case at an inclination of the first inclination angle. A coating processing apparatus is provided.
[0013]
According to the present invention, in a coating processing apparatus for forming a coating film by supplying a coating solution to a substrate to be processed, a manual instruction from the outside by an operator, etc. Depending on the operating conditions, it can be automatically cleaned by spraying the solvent inside the exhaust duct at any time, eliminating the need for complicated and time-consuming maintenance work such as disassembly and assembly of the exhaust duct. Improve equipment availability and reduce maintenance man-hours.
[0014]
In other words, the inside of the exhaust duct can be kept clean without performing complicated maintenance management work, and it is derived from mist accumulation in the exhaust duct without causing a decrease in the operation rate of the coating processing apparatus and an increase in maintenance management man-hours. It is possible to reduce coating film defects due to adhesion of foreign matter and to prevent variations in coating film thickness due to fluctuations in exhaust characteristics. In addition, the operation cost of the coating treatment apparatus can be reduced by reducing the maintenance man-hours.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
[0016]
FIG. 1 is a schematic plan view showing a resist coating and developing processing system including a resist coating processing unit as an embodiment of the coating processing apparatus of the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a rear view thereof.
[0017]
This resist coating / development processing system 1 includes a cassette station 11 serving as a transfer station, a processing station 12 having a plurality of processing units, and an exposure apparatus 14 provided adjacent to the processing station 12 and the processing station 12. And an interface station 13 for delivering the wafer W.
[0018]
In the cassette station 11, a wafer cassette (CR) containing a plurality of (for example, 25) wafers W is loaded and unloaded, and as shown in FIG. A plurality of (five in FIG. 1) positioning protrusions 20a are formed in one row. The wafer cassette (CR) can be placed at the position of the positioning projection 20a with the wafer loading / unloading port facing the processing station 12 side.
[0019]
The cassette station 11 includes a wafer transfer mechanism having a wafer transfer pick 21a. The wafer transfer pick 21a can selectively access any one of the wafer cassettes (CR), and a third processing unit group G of the processing station 12 to be described later. _Three Transition unit (TRS-G _Three ) Can be accessed.
[0020]
In the processing station 12, the third processing unit group G is arranged in order from the cassette station 11 side on the rear side of the system (upper side in FIG. 1). _Three , Fourth processing unit group G _Four And the fifth processing unit group G _Five Is arranged. The third processing unit group G _Three And the fourth processing unit group G _Four Between the first main transport section A ₁ And a fourth processing unit group G _Four And the fifth processing unit group G _Five Between the second main transport section A ₂ Is provided. Further, on the front side of the system (lower side in FIG. 1), in order from the cassette station 11 side, the first processing unit group G ₁ And second processing unit group G ₂ Is provided.
[0021]
As shown in FIG. 3, the third processing unit group G _Three Then, an oven-type processing unit that performs predetermined processing by placing the wafer W on the mounting table, for example, a high-temperature heat treatment unit (BAKE) that heat-treats the wafer W, and a high-accuracy temperature that controls the temperature of the wafer W with high accuracy. Adjustment unit (CPL-G _Three ), Temperature control unit (TCP), cassette station 11 and first main transport section A ₁ Transition unit (TRS-G) that serves as a transfer part of the wafer W between _Three ) Are stacked, for example, in 10 steps.
[0022]
Fourth processing unit group G _Four Then, for example, a pre-bake unit (PAB) that heat-treats the wafer W after resist coating, a post-bake unit (POST) that heat-treats the wafer W after development, and a high-precision temperature control unit (CPL-G) _Four ) Are stacked, for example, in 10 steps. Fifth processing unit group G _Five Then, for example, a post-exposure bake unit (PEB) that heat-treats the wafer W after exposure and before development, a high-precision temperature control unit (CPL-G) _Five ) Are stacked, for example, in 10 steps.
[0023]
As shown in FIGS. 1 and 3, the first main transport section A ₁ The sixth processing unit group G having an adhesion unit (AD) and a heating unit (HP) for heating the wafer W is provided on the back side of the substrate. ₆ Is provided.
[0024]
Second main transport section A ₂ On the back side of the wafer, a peripheral exposure device (WEE) that selectively exposes only the edge portion of the wafer W in order to remove excess resist at the peripheral portion of the wafer, and a film thickness measurement device (FTI) that measures the resist film thickness ) Having a seventh processing unit group G ₇ Is provided.
[0025]
As shown in FIGS. 1 and 2, the first processing unit group G ₁ Then, five spinner type processing units, for example, three resist coating units (COT) as liquid supply units for performing predetermined processing by placing the wafer W on the spin chuck SP in the cup (CP), and at the time of exposure A bottom coating unit (BARC) for forming an antireflection film for preventing light reflection is stacked in a total of five stages. The second processing unit group G ₂ Then, spinner type processing units, for example, development units (DEV) are stacked in five stages.
[0026]
First main transport section A ₁ Is provided with a first main wafer transfer device 16, which is connected to the first processing unit group G. ₁ , Third processing unit group G _Three , Fourth processing unit group G _Four And the sixth processing unit group G ₆ Each unit provided in can be selectively accessed. The second main transport section A ₂ Is provided with a second main wafer transfer device 17, which is connected to the second processing unit group G. ₂ , Fourth processing unit group G _Four , Fifth processing unit group G _Five , Seventh processing unit group G ₇ Each unit provided in can be selectively accessed.
[0027]
FIG. 4 is a perspective view showing a schematic structure of the first main wafer transfer device 16. The first main wafer transfer device 16 includes three arms 7a, 7b, and 7c that hold the wafer W, arm support plates 51 that are attached to the base ends of the arms 7a to 7c, and each arm support plate 51. A base 52 that is engaged, a support 53 that supports the base 52 and the like, a motor (not shown) built in the support 53, a rotating rod 54 that connects the base 52 and the motor, and a first And second processing unit group G ₁ , G ₂ A support column 55 provided on the side and having a sleeve 55a formed in the vertical direction, a flange member 56 slidably engaged with the sleeve 55a and connected to the support portion 53, and the flange member 56 being moved up and down (not shown) And an elevating mechanism.
[0028]
On the base 52, rails (not shown) are laid for each arm support plate 51 in parallel with the longitudinal direction of the base 52, and each arm support plate 51 is slidable along this rail. . Further, when the motor built in the support portion 53 is rotated, the rotating rod 54 is rotated, whereby the base 52 can be rotated in the XY plane. Furthermore, since the support portion 53 is attached to a flange member 56 that is movable in the Z direction, the base 52 is also movable in the Z direction.
[0029]
Vertical members 59a are attached to both sides of the distal end portion of the base 52, and a shielding plate 8 and a bridging member 59b for blocking radiant heat between the arms 7a and 7b are attached to the vertical members 59a. A pair of optical sensors (not shown) are provided at the center of the bridging member 59b and the tip of the base 52, thereby detecting the presence / absence of the wafer W in each of the arms 7a to 7c and the protrusion of the wafer W. It has come to be. The second main wafer transfer device 17 has the same structure as the first main wafer transfer device 16.
[0030]
The wall 57 shown in FIG. 4 is the first processing unit group G. ₁ Second main transport section A on the side ₂ Of the first processing unit group G. ₁ A window portion 57a is provided for transferring the wafer W to and from each unit provided in the. The second main transport section A ₂ Four fans 58 are provided at the bottom of the.
[0031]
First processing unit group G ₁ And the cassette station 11 and the second processing unit group G ₂ And the interface station 13 are respectively connected to the first and second processing unit groups G. ₁ , G ₂ Liquid temperature control pumps 24 and 25 for supplying a processing solution to the processing unit group G are further supplied to the processing unit group G. ₁ ~ G _Five Ducts 28 and 29 are provided to supply the interior.
[0032]
Panel on the back side of the processing station 12 and the first processing unit group G ₁ ~ Seventh processing unit group G ₇ Can be removed for maintenance. The first and second processing unit groups G ₁ , G ₂ At the lowermost stage of each, chemical units (CHM) 26 and 27 for supplying chemicals to these are provided. Further, a central control unit 19 for controlling the entire resist coating / development processing system 1 is provided below the cassette station 11.
[0033]
The interface station 13 includes a first interface station 13a on the processing station 12 side and a second interface station 13b on the exposure apparatus 14 side. The first interface station 13a includes a fifth processing unit group G. _Five The first wafer transfer body 62 is arranged so as to face the opening of the second wafer station, and the second wafer transfer body 63 movable in the X direction is arranged at the second interface station 13b.
[0034]
On the back side of the first wafer transfer body 62, the peripheral exposure apparatus (WEE), the in-buffer cassette (INBR) for temporarily storing the wafer W transferred to the exposure apparatus 14, and the exposure apparatus 14 are sequentially carried out from the top. 8th processing unit group G in which out buffer cassettes (OUTBR) for temporarily storing the wafers W are stacked ₈ Is arranged. Further, on the front side of the first wafer transfer body 62, the transition units (TRS-G ₉ ) And two-stage high-precision temperature control unit (CPL-G) ₉ ) Are stacked in the ninth processing unit group G ₉ Is arranged.
[0035]
The first wafer transfer body 62 has a fork 62a for wafer transfer. The fork 62a is connected to the fifth processing unit group G. _Five , Eighth processing unit group G ₈ , Ninth processing unit group G ₉ The units can be accessed, whereby the wafer W is transferred between the units.
[0036]
The second wafer transfer body 63 has a fork 63a for wafer transfer. This fork 63a is connected to the ninth processing unit group G ₉ These units and the in-stage 14a and out-stage 14b of the exposure apparatus 14 are accessible, and the wafer W is transferred between these units.
[0037]
In the resist coating / development processing system 1 configured as described above, one wafer W is taken out from the wafer cassette (CR) by the wafer transfer mechanism 21 and the transition unit (TRS-G) of the processing station 12 is taken. _Three Then, the first and second main wafer transfer devices 16 and 17 sequentially transfer the wafer W to each unit according to the order of the recipe, and perform a series of processes on the wafer W.
[0038]
For example, after the temperature of the wafer W is adjusted, the adhesion process in the adhesion unit (AD) and / or the formation of the antireflection film in the bottom coating unit (BARC), the heat treatment in the heating unit (HP), the high temperature heat treatment Bake processing in the unit (BAKE), temperature control of the wafer W, resist liquid coating processing in the resist coating unit (COT), pre-baking processing in the pre-baking unit (PAB), and peripheral exposure processing in the peripheral exposure device (WEE) After sequentially adjusting the temperature of the wafer W, the wafer W is transferred into the exposure apparatus 14 by the second wafer transfer body 63. After exposure by the exposure apparatus 14, the wafer W is transferred by the second wafer transfer body 63 to the transition unit (TRS-G ₉ ), The post-exposure bake process in the post-exposure bake unit (PEB), the development process in the development unit (DEV), and the post-bake process in the post-bake unit (POST) are sequentially performed to control the temperature of the wafer W. After processing, the transition unit (TRS-G _Three ) To the wafer cassette (CR) of the cassette station 11. Such a series of operations is repeated by the number of cassette wafers.
[0039]
Next, a resist coating unit (COT) for carrying out the control method of the coating processing apparatus of the present invention will be described with reference to FIGS.
[0040]
6 shows a longitudinal section along a center line of a branch end of a branch duct described later shown by a line S1-S1 in FIG. 5, and FIG. 7 shows a line S2-S2 in FIG. A plan sectional view of the part is shown.
[0041]
This resist coating unit (COT) is provided with a cup 70 (CP) which is a container for accommodating a wafer W that is taken in and out by the arms 7 a to 7 c of the first main wafer transfer device 16. A spin chuck 71 that holds W horizontally by vacuum suction is provided. The spin chuck 71 can be rotated by a drive motor 72 such as a pulse motor provided below the cup 70, and the rotation speed thereof can be arbitrarily controlled. The spin chuck 71 can be moved up and down by a lifting mechanism such as an air cylinder (not shown).
[0042]
A coating head 80 is provided above the spin chuck 71 so as to be movable between a position immediately above the spin chuck 71 and a retracted position. The coating head 80 is connected to a driving mechanism (not shown) via an arm 81. The drive mechanism is moved in the vertical and horizontal directions in FIGS. 5 and 6 and in the direction perpendicular to the paper. The application head 80 is detachable from the arm 81.
[0043]
The coating head 80 has a base member 82 and a structure in which a resist solution discharge nozzle 90 that supplies a resist solution that is a coating solution is attached to the base member 82.
[0044]
A resist solution supply pipe 91 is connected to the resist solution discharge nozzle 90, and the resist solution supply pipe 91 communicates with a resist solution tank (not shown) that stores the resist solution. Although not specifically shown, the resist solution supply pipe 91 is provided with a suck back valve, an air operation valve, a bubble removing mechanism for separating and removing bubbles in the resist solution, a filter, and a resist pump 92 in that order from the downstream side. ing. As the resist pump 92, a bellows pump having an expandable / contractible bellows or a tube diaphragm pump having a tube diaphragm that contracts by the pressure of the liquid and delivers the resist solution can be suitably used.
[0045]
A rectifying plate 70 a disposed concentrically with the cup 70 is provided below the spin chuck 71 in the cup 70.
[0046]
A pair of exhaust pipes whose upper ends protrude from the bottom of the cup by a predetermined height at the bottom of the cup 70 are closer to the center than the outer edge of the rectifying plate 70a and symmetrical with respect to the rotation axis of the spin chuck 71. The exhaust pipe 73-2 and the exhaust pipe 73-2 are connected, and the exhaust pipe 73-1 and the exhaust pipe 73-2 are used to exhaust the inside of the cup 70, thereby spreading outward from the center of the wafer W, and a rectifying plate. An exhaust flow that passes through the gap between the inner circumference of 70 a and the cup 70 and descends to the bottom of the cup 70 is formed.
[0047]
A drainage pipe 74 having an upper end opened at the same height as the bottom surface is connected to the bottom surface from the outside of the cup 70, and from this drainage pipe 74, a resist solution or the like scattered in accordance with the coating process is connected. It is discharged and collected in the cup drain case 74a. That is, the cup drain case 74a is a storage tank that is communicated by the inner bottom portion of the cup 70 and the drainage pipe 74, and collects and wastes excess resist and the like accumulated by shaking off in the coating process. The cup drain case 74a is connected to an external waste liquid treatment facility (not shown) via a waste liquid recovery pipe 74b, and the accumulated waste liquid such as a solvent or a resist solution is discharged to an external waste liquid treatment facility (not shown).
[0048]
Further, the cup drain case 74a is connected to a drain discharge pump 302 described later via a pipe 74c, and the solvent 200 sucked from the duct drain case 300 and the mist traps 401 and 402 by the drain discharge pump 302 as described later. Waste liquid such as mist liquid is collected in the cup drain case 74a.
The duct drain case 300 is a bowl-shaped storage part (second storage part) that stores the liquid discharged from the solvent nozzle nozzles 201 and 202 and the liquid mixed with the resist so as not to flow into the collecting duct 110.
The mist trap 401 and the mist trap 402 are provided at the duct bottom facing the duct side opening ends of the exhaust pipes 73-1 and 73-2 communicating with the cup 70, and are resists flowing from the exhaust pipes 73-1 and 73-2. It is the storage part (1st storage part) which stores the solvent 200 which applies the exhaust flow containing mist and dissolves mist.
In the case of the present embodiment, the lower ends of the exhaust pipe 73-1 and the exhaust pipe 73-2 are the branch ends of the branch duct 100 branched in a substantially Y shape so as to sandwich the drive motor 72 at the lower part of the cup 70. 101 and the branch end 102, and the other end of the branch duct 100 is connected via a flange 120 which is a member connected to the collective duct 110.
[0049]
In this case, a solvent nozzle 201 and a solvent nozzle 202 are provided at each branch end 101 and branch end 102 of the branch duct 100. As illustrated in FIG. 8, the solvent nozzles 201 and 202 are connected to a solvent supply pump 204 via a solvent pipe 203, and a cleaning process in which the solvent 200 is sprayed toward the connection end side with respect to the collecting duct 110. Is done. The solvent supply pump 204 can be configured by, for example, a tube diaphragm pump that pulsates and sends the solvent 200 by expansion and contraction due to compressed air.
[0050]
As an example, the solvent nozzle 201 (202) has a shower nozzle shape in which a plurality of injection ports 201b (injection ports 202b) are arranged on an injection surface 201a (injection surface 202a) as illustrated in FIG. The solvent 200 can be dispersed in a shape.
[0051]
Further, as illustrated in FIG. 13, in the solvent nozzle 201 (202), a plurality of injection ports 201d (injection ports 202d) having different ejection directions are formed on the injection surface 201c (injection surface 202c), and the solvent is sprayed. A structure in which 200 is sprayed can also be used.
[0052]
In the case of the present embodiment, the solvent 200 sprayed into the branch duct 100 from the solvent nozzles 201 and 202 may be a resist solution solvent, but is not limited thereto and can dissolve a mist of the resist coating solution. Typically, thinner is typically used.
[0053]
A duct drain case 300 is provided on the front side of the connecting end of the branch duct 100 with respect to the collective duct 110 in the exhaust flow direction, and sprayed from solvent nozzles 201 and 202 provided at the branch end 101 and the branch end 102, respectively. Solvent 200 flowing in and trapped. As illustrated in FIG. 8, a drain discharge pump 302 is connected to the duct drain case 300 via a pipe 301, and the solvent 200 and mist accumulated in the duct drain case 300 are cup drained via a pipe 74 c. It is configured to discharge to the case 74a. The drain discharge pump 302 can be configured by a tube diaphragm pump that discharges the solvent 200 accumulated in the duct drain case 300 by, for example, expanding and contracting with compressed air.
[0054]
Further, the duct drain case 300 is provided with a liquid level sensor 500 that detects the height of the liquid level of the solvent 200 or the like accumulated in the duct drain case 300. The liquid level sensor 500 is provided with a glass rod set to detect the height of the liquid level when a predetermined amount of the solvent 200 or the like is accumulated in the duct drain case 300, and the tip of the glass rod is placed on the liquid level. It is designed to detect changes in light when hit.
[0055]
At the bottom of each of the branch end 101 and the branch end 102 of the branch duct 100, a mist trap 401 and a mist trap 402 are provided at positions immediately below the lower ends of the exhaust pipes 73-1 and 73-2. A part of the solvent 200 sprayed from the nozzles 201 and 202 accumulates, and the resist solution mist contained in the descending exhaust flow blown out from the exhaust pipes 73-1 and 73-2 is captured.
[0056]
As illustrated in FIG. 8, the mist trap 401 and the mist trap 402 are connected to the drain discharge pump 302 via a pipe 403, and the accumulated solvent 200, resist solution (mist) and the like are connected via a pipe 74 c. It is discharged to the cup drain case 74a.
[0057]
As illustrated in FIGS. 5 and 6, the bottom surfaces of the branch ends 101 and 102 of the branch duct 100 are inclined at the first inclination angle θ1 so as to descend from the branch ends 101 and 102 toward the connection end of the collective duct 110. And it inclines with 2nd inclination-angle (theta) 2 so that it may go down toward the center side of the cup 70. FIG.
[0058]
As a result, the solvent 200 sprayed from the solvent nozzles 201 and 202 or the solvent 200 overflowing from the mist traps 401 and 402 in the branch ends 101 and 102 is separated from the wall surface 101a and the wall surface 102a near the center side of the cup 70. Along the branch ends 101 and 102, and flows into the duct drain case 300 and is captured.
[0059]
The outer end of the collective duct 110 is connected to an exhaust pipe (not shown) that descends the system housing via an elbow part 111 and is connected to an exhaust equipment (not shown) provided outside the system. The collective duct 110 is provided with a butterfly valve 112 and an auto damper 113 so that the exhaust flow rate in the cup 70 can be adjusted via the collective duct 110, the branch duct 100, and the exhaust pipes 73-1, 73-2. It has become.
[0060]
Next, an example of the configuration of the control system in the present embodiment will be described with reference to FIG.
[0061]
The main controller 600 for controlling the entire resist coating and developing system displays an operation panel 601 for inputting commands and control information by an operator and displaying information such as operating status, and displays alarms with sound and light. An alarm device 602 to perform is provided.
[0062]
Under the main control unit 600, a coating control unit 700 for controlling individual resist coating processing units (COT) is provided. The coating control unit 700 controls the solvent cleaning pump 204, the drain discharge pump 302, and the like in addition to controlling the coating mechanism unit such as the resist pump and the spindle motor 72, thereby controlling the duct cleaning process as described later. The function to perform.
[0063]
For simplicity, the main control unit 600 and the application control unit 700 are illustrated separately, but may be implemented as the same or independent software modules on a common computer system.
[0064]
Next, the operation and control of the resist solution coating process in the resist coating unit (COT) configured as described above will be described.
[0065]
First, a downward airflow having a predetermined flow velocity is formed inside the cup 70 by adjusting the opening degree of the butterfly valve 112 of the collective duct 110.
[0066]
In this state, when the wafer W is transported directly above the cup 70 in the resist coating unit (COT) by any of the arms 7a, 7b, 7c of the first main wafer transport device 16, the wafer W is Vacuum suction is performed by a spin chuck 71 that has been lifted by a lifting mechanism (not shown). After the wafer W is vacuum-sucked by the spin chuck 71, the main wafer transfer mechanism 22 pulls back the arm from the resist coating unit (COT) and finishes the delivery of the wafer W to the resist coating unit (COT).
[0067]
Next, the spin chuck 71 is lowered until the wafer W reaches a fixed position in the cup 70. First, the spin chuck 71 is rotated at an appropriate rotation speed by the drive motor 72 to make the temperature of the wafer W uniform.
[0068]
Thereafter, the coating head 80 is appropriately moved until the discharge port of the resist solution discharge nozzle 90 reaches the approximate center of the spin chuck 71 (approximately the center of the wafer W), and the rotation speed of the wafer W is increased to a predetermined value. The resist solution is supplied from the discharge port of the resist solution discharge nozzle 90 to substantially the center of the rotating wafer W surface, and the resist solution is diffused outward by centrifugal force to perform resist coating on the wafer W surface, and then the wafer. The rotational speed of W is increased and the remaining resist solution is shaken off. Thereafter, the rotation of the wafer W is continued and the resist film is dried. After performing this process for a predetermined time, the resist coating process is completed.
[0069]
In the course of the series of coating processes described above, a part of the resist solution scattered around the periphery of the wafer W adheres to the inner wall of the cup 70 while being partially liquid, and passes through the drain pipe 74 that opens to the bottom of the cup. Then, it is recovered in the cup drain case 74a. The other part becomes mist and rides on the exhaust flow descending the peripheral portion of the wafer W and is discharged to the branch duct 100 via the exhaust pipe 73-1 (73-2). At this time, in the case of this embodiment, the mist that is included in the exhaust flow and arrives at the branch duct 100 adheres to the mist trap 401 (402) directly below the exhaust pipe 73-1 (73-2). Mist that has been trapped and has passed without being trapped adheres to the inner wall surface of the downstream branch end 101 (102) (particularly, the portion where the flow velocity of the exhaust flow near the center of the cup 70 is low).
[0070]
The mist adhering to the inner wall or the like of the branch duct 100 in this way accumulates as the operation time elapses. Then, the mist peeled off from the inner wall of the branch duct flows back into the cup 70 and becomes a foreign substance and adheres to the wafer W coating film, causing a coating film defect or changing the flow resistance of the exhaust flow in the branch duct 100. Therefore, there is a concern that the state of the descending airflow in the cup 70 is changed to cause variation in the coating film thickness. Although it is conceivable to perform maintenance such as disassembly / cleaning / assembly of the unit every time a predetermined amount of mist adheres, as shown in FIG. 2, the present system is divided into a resist coating unit (COT). ) And the bottom coating unit (BARC) are configured to be stacked in five stages, such maintenance is complicated and causes a significant decrease in throughput.
[0071]
Therefore, in the case of the present embodiment, the coating control unit 700 automatically enters the exhaust duct as described below at any time according to an operator's instruction, or automatically every predetermined number of wafers W or the number of processing lots. Automatic cleaning process is performed.
[0072]
Hereinafter, an example of the automatic cleaning process in the exhaust duct according to the present embodiment will be described with reference to FIGS.
[0073]
First, the coating control unit 700 receives an automatic cleaning start timing due to reaching the number of processed wafers or the number of processing lots of a predetermined wafer W, or a cleaning start instruction by manual activation by command input from the operation panel 601 or the like. The presence or absence is constantly monitored (steps 801 and 802).
[0074]
When cleaning is started, first, the drain discharge pump 302 is started (step 803), and the solvent supply pump 204 is started to start spraying the solvent 200 from the solvent nozzles 201 and 202 into the branch duct 100. (Step 804).
[0075]
At this time, the mist of the resist solution adhering to the mist trap 401 (402) is dissolved and removed by the solvent 200 sprayed in the branch duct 100, and flows into the duct drain case 300 at the inclination of the first inclination angle θ1. It is captured and discharged to the cup drain case 74a by the drain discharge pump 302 via the pipe 301 and the pipe 74c. Further, since the solvent 200 flows so as to gather on the wall surface near the center of the cup 70 where the mist easily adheres as described above due to the inclination of the second inclination angle θ2 of the branch duct 100, it is possible to further dissolve and remove the attached mist. Can be done effectively.
[0076]
Then, while the liquid level of the solvent 200 in the duct drain case 300 is monitored by the liquid level sensor 500 (step 805), automatic cleaning is performed by spraying the solvent 200 into the branch duct 100 for a predetermined time (P minutes in FIG. 11). (Step 806).
[0077]
When the cleaning time is performed for a predetermined time, the solvent supply pump 204 is stopped (step 807), and after a predetermined delay time (Q = (P + N) minutes in FIG. 11) has elapsed (step 808), the drain The discharge pump 302 is stopped (step 809), the automatic cleaning is terminated, and the process returns to step 801 and waits.
Here, the reason for providing the delay time N from the stop of the solvent supply pump 204 to the stop of the drain discharge pump 302 is that the liquid such as the solvent 200 flows from the mist traps 401 and 402 to the duct drain case 300. This is to wait for time.
[0078]
Further, if it is detected in step 805 during cleaning that the liquid level of the solvent 200 in the duct drain case 300 exceeds a predetermined height (preliminarily set to the overflow level or lower), the liquid level is exceeded. It is determined whether or not the state has continued for a predetermined time (step 810), and when the liquid level excess state continues for a predetermined time or longer, the overflow of the solvent 200 from the duct drain case 300 to the collecting duct 110 side is avoided. Accordingly, the alarm device 602 is activated to issue a warning to the operator (step 811), and the process proceeds to the cleaning end process after the stop of the solvent supply pump 204 in step 807, and the automatic cleaning is interrupted.
[0079]
FIG. 11 shows an example of operations of the solvent supply pump 204 and the drain discharge pump 302 during cleaning. The example of FIG. 11 shows an example in which automatic cleaning is automatically executed at the start of a lot and every 400 lots as a trigger for starting automatic cleaning of the mist in the branch duct 100.
[0080]
The solvent supply pump 204 pumps the solvent 200 to the solvent nozzles 201 and 202 only for the cleaning time P minutes in a pulsation operation of repeating discharge time A seconds: discharge pause B seconds.
[0081]
At the same time, the drain discharge pump 302 performs an operation of sucking the solvent 200 in the duct drain case 300 and discharging it to the cup drain case 74a for Q (= P + N) minutes. Here, since Q> P, and the operation time (Q) of the drain discharge pump 302 is made longer by N minutes than the operation time (P) of the solvent supply pump 204, the mist traps 401 and 402 are connected to the duct drain case 300. It can be discharged after waiting until the liquid such as the solvent 200 flows. Thus, in preparation for the next cleaning, the solvent 200 accumulated in the duct drain case 300 after the cleaning can be surely removed and emptied.
[0082]
As described above, according to the present embodiment, in each of the individual resist coating units (COT) stacked, cleaning and removal of mist adhering in the branch duct 100 is automatically performed according to the operation status. Therefore, time-consuming and complicated maintenance work such as disassembling and assembling the branch duct 100 and the collective duct 110 for cleaning work is completely eliminated, and the resist coating unit (COT) and further resist coating and developing are eliminated. The operating rate of the entire processing system can be improved.
[0083]
Further, the number of man-hours required for cleaning the branch duct 100 is completely eliminated, and maintenance management costs can be greatly reduced.
[0084]
Furthermore, since the inside of the branch duct 100 can be maintained clean by washing and removing the mist and the like in the branch duct 100 without requiring complicated maintenance management work, the mist adhering to the branch duct 100 is peeled off and the inside of the cup 70 is removed. In addition to reducing defects in the coating film caused by backflowing into the coating film on the wafer W as a foreign substance, and stabilizing the downdraft in the cup 70 by stabilizing the exhaust flow passing through the branch duct 100. Improvement of coating film thickness uniformity can be realized.
[0085]
In the above description, the solvent 200 in the mist traps 401 and 402 provided at the branch ends 101 and 102 of the branch duct 100 is drained by the drain discharge pump 302. Alternatively, the solvent 200 sprayed from 202 may be stored, and the mist generated in the cup 70 during the coating process may be dissolved and captured in the solvent 200 stored in the mist traps 401 and 402. In this case, since the mist becomes liquid and accumulates in the mist traps 401 and 402, the generation of foreign matters derived from the mist in the branch duct 100 can be further reduced. The solvent 200 overflowing the mist traps 401 and 402 is captured and collected by the downstream duct drain case 300.
[0086]
Further, the mist traps 401 and 402 may be completely omitted. In this case, a large amount of mist adheres to the portion immediately below the exhaust pipe 73-1 (73-2), but since it is in the vicinity of the solvent nozzle 201 (202), the solvent 200 sprayed from the solvent nozzle 201 (202). Can be efficiently dissolved and removed.
[0087]
In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, the automatic exhaust duct cleaning mechanism of the present invention described above may be provided in the cup exhaust system of the development unit (DEV).
[0088]
Furthermore, in the above-described embodiment, a case where a semiconductor wafer is used as the substrate to be processed has been described. However, the present invention is not limited to the semiconductor wafer, but may be another substrate to be processed such as an FPD (flat panel display) substrate or a mask reticle substrate. May be.
[0089]
【The invention's effect】
As described above, according to the present invention, it is possible to improve the operating rate of the coating treatment apparatus and reduce the maintenance management man-hours.
[0090]
In addition, according to the present invention, the coating film caused by the reduction of coating film defects due to the adhesion of foreign matters derived from the exhaust duct and the fluctuation of the exhaust characteristics without causing a decrease in the operating rate of the coating processing apparatus and an increase in the maintenance man-hours. It becomes possible to prevent thickness variations.
[Brief description of the drawings]
FIG. 1 is a plan view showing the overall configuration of a resist coating and developing processing system for a semiconductor wafer on which a resist coating processing unit for carrying out the present invention is mounted.
FIG. 2 is a front view of the resist coating and developing system shown in FIG.
3 is a rear view of the resist coating and developing treatment system shown in FIG. 1. FIG.
4 is a perspective view showing a schematic structure of a main wafer transfer device provided in the resist coating and developing treatment system of FIG. 1. FIG.
FIG. 5 is a cross-sectional view showing an overall configuration of a resist coating processing unit mounted on the coating and developing processing system shown in FIG. 1;
6 is a longitudinal sectional view of the resist coating unit shown in FIG.
7 is a plan sectional view of the resist coating unit shown in FIG.
8 is a piping diagram of an exhaust duct system of the resist coating unit shown in FIG.
9 is a conceptual diagram of a control system of the resist coating unit shown in FIG.
10 is a flowchart showing an example of an operation of an automatic cleaning process in the resist coating unit shown in FIG.
11 is a diagram showing an example of an operation of an automatic cleaning process in the resist coating unit shown in FIG.
12 is a cross-sectional view showing an example of a configuration of a solvent nozzle provided in an exhaust duct system of the resist coating unit shown in FIG.
13 is a cross-sectional view showing an example of a configuration of a solvent nozzle provided in an exhaust duct system of the resist coating unit shown in FIG.
[Explanation of symbols]
70 …… Cup
70a …… Rectifying plate
73-1 Exhaust pipe
73-2 …… Exhaust pipe
74 …… Drainage pipe
74a …… Cup drain case
74b: Waste liquid recovery piping
74c …… Piping
80 …… Application head
81 …… Arm
82 …… Base member
90 …… Resist liquid discharge nozzle
91 …… Resist solution supply piping
92 …… Registration pump
100 …… Branch duct
101 …… Branch end
101a: Wall surface that mist easily attaches
102 …… Branch end
102a …… Wall surface on which mist adheres
110 …… Meeting duct
111 …… Elbow club
112 …… Butterfly valve
113 …… Auto damper
120 …… Flange
200 …… Solvent
201 …… Solvent nozzle
201a …… Injection surface
201b …… Injection port
201c ... injection surface
201d …… Injection port
202 …… Solvent nozzle
202a …… Injection surface
202b …… Injection port
202c ... injection surface
202d …… Injection port
203 …… Solvent piping
204 …… Solvent supply pump
300 …… Duct drain case
301 …… Piping
302 …… Drain discharge pump
401 …… Mist trap
402 …… Mist trap
403 …… Piping
500 …… Liquid level sensor
600 …… Main control unit
601 …… Control panel
602 …… Alarm
700 …… Application control unit
W …… Semiconductor wafer (substrate to be processed)
θ1 …… First tilt angle
θ2 …… Second tilt angle

Claims (8)

A coating processing apparatus for forming a coating film by supplying a coating liquid to a substrate to be processed,
A substrate holding member that holds and rotates the substrate to be processed substantially horizontally;
A coating liquid discharge nozzle for discharging the coating liquid to the substrate to be processed held by the substrate holding member;
A storage container for storing the substrate to be processed held by the substrate holding member;
An exhaust duct for exhausting the interior of the container;
A duct cleaning mechanism that sprays and cleans the solvent inside the exhaust duct ;
A duct drain case provided in the exhaust duct, into which the solvent sprayed into the exhaust duct flows, and
The exhaust duct includes a plurality of exhaust pipes communicating with the bottom of the containing container, a branch duct connected to the exhaust pipe, and a collective duct connected to the branch duct,
A bottom surface of the branch duct forms a slope having a first slope angle that falls from a connection end side to the exhaust pipe to a connection end side to the collective duct, and a slope having a second slope angle at which the mist adhesion region is relatively low ,
The solvent sprayed inside the branch duct flows so as to gather in the mist adhesion region due to the inclination of the second inclination angle, and flows into the duct drain case with the inclination of the first inclination angle. The coating processing apparatus characterized by the above-mentioned .   The control device according to claim 1, further comprising a control unit that controls a cleaning operation inside the exhaust duct by the duct cleaning mechanism according to a manual instruction from the outside or an operating state of the coating treatment apparatus. Application processing equipment.   The coating according to claim 1, wherein the duct cleaning mechanism includes a solvent nozzle that sprays a solvent into the exhaust duct, and a solvent pump that supplies the solvent to the solvent nozzle. Processing equipment. Coating treatment apparatus according to claim 1 or claim 2, characterized by further comprising a drain discharge pump for discharging the solvent before Symbol duct drain casing.   The liquid level sensor for monitoring the liquid level of the solvent flowing into the duct drain case, and an alarm generation mechanism for generating an alarm when the liquid level sensor exceeds a predetermined value. Application processing equipment.   6. The coating treatment apparatus according to claim 1, wherein the exhaust duct is provided with a mist trap that captures a mist of the coating liquid flowing from the storage container. Claims wherein the said solvent nozzle disposed in each of the connection end portion for an individual of the exhaust pipe of the branch duct, wherein the duct drain case the connection end with respect to the set duct of the branch duct is disposed Item 2. The coating apparatus according to Item 1 . 2. The coating process according to claim 1 , wherein the mist trap is disposed at a portion where an exhaust flow blown out from the exhaust pipe abuts at each of connection end portions of the branch ducts to the individual exhaust pipes. apparatus.

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