JP3760131B2 - Processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a frequency of dummy dispensation of a resist solution. <P>SOLUTION: There are three conditions: a condition (1) that a resist solution used for a certain lot is replaced with the other type of a resist solution for a following lot, a condition (2) that a time longer than an allowable time elapses after the processing of a preceding lot is finished, and a condition (3) that the processing of the prescribed number of lots is finished after the dummy dispensation of a resist solution is carried out. When one of the three conditions is satisfied, the dummy dispensation of a resist solution is carried out before a following lot is subjected to processing. When none of the three conditions (1) to (3) are satisfied, a following lot is subjected to processing without carrying out dummy dispensation. <P>COPYRIGHT: (C)2003,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate processing method.
[0002]
[Prior art]
In the manufacturing process of a semiconductor device, for example, a resist coating process is performed in which a resist solution is supplied to a semiconductor wafer (hereinafter referred to as “wafer”) to form a resist film on the wafer surface.
[0003]
This resist coating process is performed, for example, by supplying a predetermined amount of resist solution from the nozzle to the center of the wafer in a resist coating apparatus, rotating the wafer, and diffusing the resist solution on the wafer surface by the centrifugal force. . The supply of the resist solution to the nozzle at this time is performed, for example, by pumping the resist solution in the storage tank by a pump through a supply pipe. Wafers are successively carried into the resist coating apparatus, and the resist coating process is continuously performed on each wafer. The continuous resist coating process is sequentially performed for each lot.
[0004]
By the way, when the supply of the resist solution to the wafer is stopped, the resist solution remains in the nozzle and the supply pipe. The remaining resist solution dries or deteriorates when left for a long time. For this reason, so-called dummy dispensing, in which the resist solution in the nozzle and the supply pipe is discharged, is performed at the break between wafer lots. This dummy dispensing is always performed every time a lot of wafers is changed for reasons such as easier control than in the past.
[0005]
[Problems to be solved by the invention]
However, if a dummy dispense is performed each time the lot is changed in this way, the resist solution due to the dummy dispense is almost discarded, and the amount of wasted resist solution increases. In addition, once dummy dispensing is performed, the next wafer processing cannot be started during that time, so the greater the number of dummy dispensings, the lower the processing throughput.
[0006]
The present invention has been made in view of the above points, and an object of the present invention is to provide a method for processing a substrate such as a wafer in which the number of dummy dispenses of a processing solution such as a resist solution is reduced as much as possible.
[0007]
[Means for Solving the Problems]
  As a reference example,A processing method for sequentially performing a substrate processing for supplying a processing liquid to a substrate on a plurality of substrates, including a step of performing a dummy dispensing of the processing liquid at a break of a substrate lot, and the step of performing the dummy dispensing includes: There is a processing method that is performed only when the type of processing solution to be supplied is changed between lots.ProposalIs done.
[0008]
  Reference example aboveAccording to the above, dummy dispensing is performed only when the type of the processing liquid is changed between lots, and is not performed every time the lot is changed as in the prior art, so the number of dummy dispensings can be reduced. Therefore, the total amount of processing liquid consumed can be reduced. In addition, when dummy dispensing is not performed, processing of the next substrate can be started immediately, and the processing efficiency of the substrate can be improved.
[0009]
  As a reference example,A processing method for sequentially performing a substrate processing for supplying a processing liquid to a substrate on a plurality of substrates, including a step of performing a dummy dispensing of the processing liquid at a break of a substrate lot, and the step of performing the dummy dispensing includes: There is a processing method that is performed only when the condition of either the type of processing liquid to be supplied is changed between lots or the predetermined time has elapsed since the processing of the previous lot is completed.Can make a suggestion.The “processing of the previous lot” is the processing of the lot immediately before the cut of the lot.
[0010]
  Reference example aboveAccording to the above, since dummy dispensing is performed when the type of processing liquid is changed, the frequency of dummy dispensing is reduced as compared with the prior art, and the consumption of processing liquid can be reduced. Further, if the time from the end of the processing of the previous lot to the start of processing of the new lot is long, the processing liquid in the processing liquid supply mechanism such as the nozzle and the supply pipe may be deteriorated. According to the present invention, since the dummy dispensing is performed even when a predetermined time has elapsed after the processing of the previous lot is completed, the quality of the processing liquid supplied to the substrate can be sufficiently ensured.
[0011]
  BookAccording to the invention, there is provided a processing method for sequentially performing a substrate processing for supplying a processing liquid to a substrate on a plurality of substrates, including a step of performing a dummy dispensing of the processing liquid at a break of the substrate lot. The process is performed when the condition of either the type of processing solution supplied is changed between lots or the processing of a predetermined number of lots has been completed since the previous dummy dispensing was performed. Only doneThe number of lots that do not need to be dispensed is determined for each of a plurality of types of processing solutions, and the smallest number of lots processed is set as the predetermined number for the lot processing.A processing method is provided.
[0012]
According to the present invention, since dummy dispensing is performed when the type of processing liquid is changed, the frequency of dummy dispensing is reduced as compared with the prior art, and the consumption of processing liquid can be reduced. Further, since the dummy dispensing is performed even when the processing of a predetermined number of lots has been completed since the previous dummy dispensing was performed, for example, nozzles that are gradually accumulated by continuously supplying the processing liquid. And bubbles in the supply pipe can be appropriately eliminated. Thereby, it can suppress that a bubble etc. are contained in the process liquid supplied to a board | substrate.
[0013]
  BookAccording to the invention, there is provided a processing method for sequentially performing a substrate processing for supplying a processing liquid to a substrate on a plurality of substrates, including a step of performing a dummy dispensing of the processing liquid at a break of the substrate lot. In the process of performing a process, the type of processing solution is changed between lots, a predetermined time has elapsed since the processing of the previous lot was completed, or a predetermined number of lots have been processed since the previous dummy dispensing was performed. Only if one of the conditions for processing has been completedThe number of lots that do not need to be dispensed is determined for each of a plurality of types of processing solutions, and the smallest number of lots processed is set as the predetermined number for the lot processing.A processing method is provided.
[0014]
According to the present invention, dummy dispensing is performed when the type of processing solution is changed between lots, so that the number of dummy dispensing operations is reduced compared to the conventional case, and the consumption of processing solution can be reduced. Further, since the dummy dispensing is performed even when a predetermined time has elapsed after the processing of the previous lot is completed, it is possible to prevent the processing liquid supplied to the substrate from being deteriorated. Furthermore, since the dummy dispensing is performed even when the processing of a predetermined number of lots has been completed since the previous dummy dispensing was performed, for example, nozzles or supply pipes accumulated by continuously supplying the processing liquid are used. Bubbles can be discharged. Thereby, it can suppress that unnecessary objects, such as a bubble, are contained in the process liquid supplied to a board | substrate. Note that the previous dummy dispense is preferably the last dummy dispense that was performed last.
[0015]
The number of lots processed to recognize the predetermined number of conditions may be counted, and the count of the number of processed lots may be reset each time the dummy dispensing is performed. As a result, even when dummy dispensing is performed under other conditions such as changing the type of resist solution, the lot number count is reset, and as a result, dummy dispensing is performed according to the lot processing number condition. As a result, the frequency of dummy dispensing can be reduced.
[0016]
  As another reference example,A processing method for sequentially performing a substrate processing for supplying a processing liquid to a substrate on a plurality of substrates, including a step of performing a dummy dispensing of the processing liquid at a break of a substrate lot, and the step of performing the dummy dispensing includes: The type of processing liquid to be supplied is changed between lots, a predetermined time has passed since the processing of the previous lot was completed, or a predetermined number of substrates were processed after the previous dummy dispense was performed The processing method that is performed only when either of the above conditions is metCan make a suggestion.
[0017]
  Reference example aboveAccording to the above, since dummy dispensing is performed when the type of processing liquid is changed between lots, the frequency of dummy dispensing can be reduced as compared with the conventional case. Further, since the dummy dispensing is performed even when a predetermined time has elapsed after the processing of the previous lot is completed, it is possible to prevent the processing liquid supplied to the substrate from being deteriorated. Furthermore, since the dummy dispensing is performed even when a predetermined number of substrates have been processed since the previous dummy dispensing was performed, the bubbles are discharged before a large amount of bubbles are accumulated in the nozzle and the supply pipe. can do. Thereby, the quality of the processing liquid supplied to the substrate can be maintained constant. The number of processed substrates may be counted in order to recognize the predetermined number of conditions, and the count of processed substrates may be reset each time the dummy dispense is performed.
[0018]
The dummy dispensing may be performed at the start of the first lot processing. According to the present invention, before the processing of the first lot is started, dummy dispensing can be performed, for example, at the time of starting up the processing apparatus that performs the processing method. Thereby, a desired processing liquid can be supplied to the substrate from the processing of the first lot, and appropriate processing can be performed.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described. FIG. 1 is a plan view showing an outline of the configuration of a coating and developing treatment system 1 in which the processing method according to the present embodiment can be performed. FIG. 2 is a front view of the coating and developing treatment system 1. FIG. 1 is a rear view of a coating and developing treatment system 1. FIG.
[0020]
As shown in FIG. 1, the coating and developing treatment system 1 is a cassette that carries, for example, 25 wafers W in and out of the coating and developing treatment system 1 from the outside in a cassette unit, and carries a wafer W in and out of the cassette C. The wafer between the station 2, a processing station 3 in which various processing apparatuses that perform predetermined processing in a single-wafer type in the coating and developing processing step, and an exposure apparatus (not shown) adjacent to the processing station 3 are arranged. It has a configuration in which the interface unit 4 for transferring W is integrally connected.
[0021]
In the cassette station 2, a plurality of cassettes C can be placed in a line in a X direction (vertical direction in FIG. 1) at a predetermined position on the cassette placement table 5 serving as a placement portion. The wafer transfer body 7 that can be transferred in the cassette arrangement direction (X direction) and the wafer arrangement direction (Z direction; vertical direction) of the wafer W accommodated in the cassette C is movable along the transfer path 8. It is provided so that each cassette C can be selectively accessed.
[0022]
The wafer carrier 7 has an alignment function for aligning the wafer W. As will be described later, the wafer carrier 7 can also access an extension device 32 belonging to the third processing device group G3 on the processing station 3 side.
[0023]
The processing station 3 is provided with a main transfer device 13 at the center thereof, and various processing devices are arranged in multiple stages around the main transfer device 13 to form a processing device group. In the coating and developing processing system 1, four processing device groups G1, G2, G3, and G4 are arranged, and the first and second processing device groups G1 and G2 are arranged on the front side of the coating and developing processing system 1. The third processing unit group G3 is disposed adjacent to the cassette station 2, and the fourth processing unit group G4 is disposed adjacent to the interface unit 4. Further, as an option, a fifth processing unit group G5 indicated by a broken line can be separately arranged on the back side. The main transfer device 13 can carry in and out the wafer W to and from various processing devices (described later) arranged in these processing device groups G1, G2, G3, G4, and G5. Note that the number and arrangement of the processing device groups vary depending on the type of processing performed on the wafer W, and the number of processing device groups can be arbitrarily selected as long as it is one or more.
[0024]
In the first processing unit group G1, for example, as shown in FIG. 2, a resist coating unit 17 for performing the processing method according to the present embodiment and a development processing unit 18 for developing the wafer W after exposure are provided. Are arranged in two stages in order. Similarly, in the second processing unit group G2, a resist coating unit 19 and a development processing unit 20 are arranged in two stages in order from the bottom.
[0025]
In the third processing unit group G3, for example, as shown in FIG. 3, a cooling unit 30 for cooling the wafer W, an adhesion unit 31 for improving the fixability between the resist solution and the wafer W, and the transfer of the wafer W are performed. For example, an extension device 32, pre-baking devices 33 and 34 for evaporating the solvent in the resist solution, and a post-baking device 35 for performing a heat treatment after the development processing are stacked in, for example, six stages from the bottom.
[0026]
In the fourth processing unit group G4, for example, a cooling unit 40, an extension / cooling unit 41 that naturally cools the mounted wafer W, an extension unit 42, a cooling unit 43, a post-exposure baking unit 44 that performs heat treatment after exposure, 45 and post-baking devices 46 are stacked, for example, in seven steps from the bottom.
[0027]
For example, a wafer carrier 50 is provided at the center of the interface unit 4 as shown in FIG. The wafer carrier 50 is configured to be freely movable in the X direction (vertical direction in FIG. 1) and Z direction (vertical direction) and rotated in the θ direction (rotating direction around the Z axis). , Access to the extension / cooling device 41, the extension device 42, the peripheral exposure device 51 and the exposure device (not shown) belonging to the fourth processing unit group G4, and the wafer W can be transferred to each of them. Yes.
[0028]
Next, the configuration of the resist coating apparatus 17 described above will be described. FIG. 4 is an explanatory view of a longitudinal section showing an outline of the configuration of the resist coating apparatus 17, and FIG. 5 is an explanatory view of a transverse section of the resist coating apparatus 17.
[0029]
For example, as shown in FIG. 4, the resist coating apparatus 17 includes a casing 17 a, and a spin chuck 50 for holding and rotating the wafer W is provided at the center of the casing 17 a. The upper surface of the spin chuck 50 is formed horizontally, and a suction port (not shown) for adsorbing the wafer W, for example, is provided on the upper surface. Accordingly, the spin chuck 50 can hold the wafer W by suction.
[0030]
For example, a drive unit 51 of the spin chuck 50 is provided below the spin chuck 50. The drive unit 51 includes, for example, a motor for rotating the spin chuck 50 at a predetermined speed, a cylinder for moving the spin chuck 50 up and down, and the like.
[0031]
A cup 52 is provided outside the spin chuck 50 for receiving and collecting a resist solution or the like scattered from the wafer W. The cup 52 has a substantially cylindrical shape with an upper surface opened, and is formed so as to surround the outer side and the lower side of the wafer W on the spin chuck 50. On the lower surface 52a of the cup 52, for example, a drain pipe 53 for draining the collected resist solution and an exhaust pipe 54 for exhausting the atmosphere in the cup 52 are provided.
[0032]
A cleaning liquid supply nozzle 55 is provided inside the cup 52 and below the wafer W held by the spin chuck 50. The cleaning liquid supply nozzle 55 can supply a cleaning liquid such as thinner to the back surface of the wafer W to clean the back surface of the wafer W.
[0033]
The resist coating device 17 includes two resist solution supply nozzles 60 and 61 for supplying a resist solution to the wafer W, for example, as shown in FIG. The resist solution supply nozzles 60 and 61 are held by the nozzle arm 62 as shown in FIG. The nozzle arm 62 is positioned at the column 63 extending in the vertical direction, the horizontal axis 64 extending from the column 63 in the horizontal direction, for example, the X direction, and the tip of the horizontal axis 64, and holds the resist solution supply nozzles 60 and 61. The holding part 65 to be configured. The support 63 is vertically extendable by a drive mechanism such as a cylinder, and the horizontal shaft 64 is also extendable horizontally by a drive mechanism such as a motor. Thereby, the holding | maintenance part 65 can be moved to an up-down direction and a X direction. The holding unit 65 is provided with an attaching / detaching mechanism (not shown) such as a solenoid, and the holding unit 65 can hold or release the resist solution supply nozzle 60 or 61 at a predetermined timing.
[0034]
Further, as shown in FIG. 5, a rail 66 extending in the Y direction is provided on the X direction negative direction side (left direction in FIG. 5) of the cup 52, and the nozzle arm 62 is driven on the rail 66 by a driving mechanism. (Not shown) is movably provided. As a result, the nozzle arm 62 can move from a standby portion S of the resist solution supply nozzles 60 and 61, which will be described later, to the top of the cup 52, whereby the nozzle arm 62 conveys the resist solution supply nozzles 60 and 61 in this section. it can.
[0035]
In the standby unit S, for example, two resist solution supply nozzles 60 and 61 can stand by. The standby unit S is provided with a storage tank 67 for storing a cleaning liquid such as thinner. The storage tank 67 is provided with a cleaning liquid supply pipe 68 that supplies the cleaning liquid into the cleaning tank 67 and a discharge pipe 69 that drains the cleaning liquid and the like in the cleaning tank 67. A predetermined amount of cleaning liquid can be stored in the storage tank 67, and the resist liquid supply nozzles 60 and 61 can be immersed in the cleaning liquid during standby. It is also possible to perform a dummy dispensing of the resist solution into the cleaning tank 67 from the resist solution supply nozzles 60 and 61 and drain the discharged resist solution from the discharge pipe 69.
[0036]
For example, as shown in FIG. 6, the resist solution supply nozzles 60 and 61 are connected to supply pipes 70 and 71, respectively. The supply pipes 70 and 71 are storage tanks 72 and 73, which are resist solution supply sources, respectively. It is connected in communication. The storage tank 72 stores the resist solution A, and the storage tank 73 stores the resist solution B. Therefore, the resist liquid A supplied from the storage tank 72 through the supply pipe 70 is discharged from the resist liquid supply nozzle 60, and the resist liquid B supplied from the storage tank 73 through the supply pipe 71 from the resist liquid supply nozzle 61. Is discharged.
[0037]
The supply pipes 70 and 71 are respectively provided with pumps 74 and 75 for pressure-feeding the resist solution to the resist solution supply nozzles 60 and 61, and adjusting valves 76 and 77 for controlling the discharge amount of the resist solution. ing.
[0038]
The operations of the pumps 74 and 75 and the control valves 76 and 77 are controlled by, for example, the main control unit 78. The main controller 78 can also control the operation of other drive mechanisms such as the drive unit 51, for example, of the resist coating device 17, and can control the resist coating device 17 as a whole. The main control unit 78 includes a control unit (not shown) such as a CPU, a storage unit (not shown) such as a RAM, an input unit (not shown) for inputting set values and the like, command signals to each drive unit, etc. An output unit (not shown) for outputting is configured.
[0039]
The main control unit 78 stores a processing program P1 in which processing conditions for wafers W for each lot are set. By executing the processing program P1, the main control unit 78 can control the pumps 74 and 75, the control valves 76 and 77, etc., and execute predetermined processing for each lot.
[0040]
In the main control unit 78, for example, a determination program P2 for determining whether or not to perform dummy dispensing of a resist solution is stored. By executing this determination program P2, the main control unit 78, for example, changes the type of the resist solution between the preceding and succeeding lot processing (condition (1)), and the elapsed time T after the previous lot processing is completed. Preset tolerance time T_MFor example, the number of processed lots N exceeds 600 sec (condition (2)), or the number of processed lots N after the previous dummy dispense is performed._MFor example, if any of the conditions for exceeding 10 lots (condition (3)) is satisfied, a determination is made to perform dummy dispensing. If neither is satisfied, a determination is made not to perform dummy dispensing. Do. When it is determined that dummy dispensing is to be performed, the pumps 74 and 75 and the like are operated according to an instruction from the main control unit 78, and dummy dispensing is performed.
[0041]
Whether or not the type of the resist solution under the condition (1) is changed can be known from, for example, the setting conditions of the processing program P1. The main control unit 78 includes, for example, a time measurement function 79 and a lot processing number counting function 80. The elapsed time T of the condition (2) is measured by the time measurement function 79, and the number of lots processed under the condition (3). N can be measured by the lot processing number counting function 80. The lot processing number counting function 80 is reset each time dummy dispensing is performed, and the count number is reset to zero.
[0042]
A duct 81 is connected to the upper surface of the casing 17a to supply a clean gas such as nitrogen gas, inert gas, air, etc. into the cup 52 as shown in FIG. Thus, for example, the gas can be supplied during the wafer W coating process or during the dummy dispensing of the resist solution, and the inside of the cup 52 can be maintained in a predetermined atmosphere.
[0043]
Next, a wafer W processing method performed by the resist coating apparatus 17 configured as described above will be described together with a series of photolithography process processes performed by the coating and developing processing system 1.
[0044]
First, one unprocessed wafer W is taken out from the cassette C by the wafer transfer body 7 and transferred to the extension device 32 belonging to the third processing unit group G3. Next, the wafer W is carried into the adhesion device 31 by the main transfer device 13, and for example, HMDS is applied on the wafer W to improve the adhesion of the resist solution. Next, the wafer W is transferred to the cooling device 30 and cooled to a predetermined temperature. The wafer W cooled to a predetermined temperature is transferred by the main transfer device 13 to, for example, the resist coating device 17.
[0045]
The wafer W that has undergone the resist coating process in the resist coating unit 17 is sequentially transferred to the pre-baking unit 33 and the extension / cooling unit 41 by the main transfer unit 13, and further, the peripheral exposure unit 51 and the exposure unit (FIG. (Not shown) are sequentially conveyed, and predetermined processing is performed in each device. The wafer W after the exposure processing is returned to the extension device 42 by the wafer carrier 50, and then the post-exposure baking device 44, the cooling device 43, the development processing device 18, the post-baking device 46, and the cooling by the main carrier device 13. It is sequentially conveyed to the device 30 and predetermined processing is performed in each device. Thereafter, the wafer W is returned to the cassette C through the extension device 32, and a series of photolithography processes is completed.
[0046]
Next, the above-described resist coating process will be described. When the coating / development processing system 1 is started up, that is, at the start of the first lot processing, for example, a dummy dispensing of the resist solution A is performed from the resist solution supply nozzle 60 used in the lot processing. In the wafer processing for each lot, a processing program P1 is executed, and a resist coating process is performed according to the processing program P1.
[0047]
For example, before the wafer W is transferred into the casing 17a, air adjusted to a predetermined temperature and humidity is supplied from the duct 81, and the inside of the casing 17a is maintained in a predetermined atmosphere. At this time, the supplied air is exhausted from the exhaust pipe 54 to the outside of the resist coating device 17.
[0048]
Then, when the wafer W is carried into the casing 17 a by the main transfer device 13, the wafer W is delivered to the spin chuck 50 that has been raised in advance and is held by suction on the spin chuck 50. Subsequently, the spin chuck 50 is lowered and the wafer W is accommodated in the cup 52. Then, for example, the resist solution supply nozzle 60 that has been waiting in the standby portion S is held by the nozzle arm 62 and moved to above the center portion of the wafer W in the cup 52.
[0049]
When the resist solution supply nozzle 60 is positioned above the center portion of the wafer W, the pump 74 and the adjusting valve 76 are actuated by an instruction from the main control unit 78, and a predetermined amount of resist solution A is discharged from the resist solution supply nozzle 60. . As a result, a predetermined amount of resist solution A is supplied to the center of the wafer W. Subsequently, the wafer W is rotated at a predetermined rotational speed, for example, 1500 rpm, and the resist solution A is diffused on the surface of the wafer W by the rotation of the wafer W. When the resist solution is diffused for a predetermined time and the resist solution is diffused over the entire surface of the wafer W, the rotational speed of the wafer W is accelerated to, for example, 2000 rpm, and the film thickness of the liquid film of the resist solution is adjusted.
[0050]
When the film thickness is adjusted, the rotation speed of the wafer W is reduced to, for example, 500 rpm. Then, a cleaning liquid such as thinner is supplied from the cleaning liquid supply nozzle 55 to the back surface of the wafer W, and the back surface of the wafer W is cleaned. Thereafter, the supply of the cleaning liquid is stopped, and the wafer W is rotated as it is, for example, at 500 rpm, and the wafer W is dried.
[0051]
When the drying process of the wafer W is completed, the rotation of the wafer W is stopped, the wafer W is transferred from the spin chuck 50 to the main transfer device 13 and is carried out of the casing 17a, and a series of resist coating processes of the wafer W are performed. finish.
[0052]
When the resist coating process for the wafer W is completed, the next wafer is immediately loaded and the same process is performed. Thus, a predetermined number of wafers are processed in a single wafer manner, and the processing of this lot is completed.
[0053]
For example, as shown in FIG. 7, when the processing of the lot R1 is completed, the time measurement function 79 starts time measurement. For example, immediately before the processing of the next lot R2 is started, the main control unit 78 executes the determination program P2, and determines whether or not the above conditions (1) to (3) are satisfied. That is, whether the resist solution used in the next lot R2 is, for example, a resist solution B different from the resist solution A of the lot R1, or the elapsed time T> the allowable time T_MOr lot processing number N> allowable lot processing number N_MIs determined. If any one of the conditions (1) to (3) is satisfied, the resist solution used in the next lot R2 is loaded before the next wafer is loaded into the resist coating unit 17. The pump 75 or 76 and the control valve 76 or 77 are operated to perform dummy dispensing of the resist solution. At this time, the resist solution supply nozzles 60 and 61 are in the cleaning tank 67, and the dummy dispensing is performed in the cleaning tank 67. Then, the time measuring function 79 and the lot processing number counting function 80 are reset.
[0054]
On the other hand, if none of the above conditions (1) to (3) is satisfied, dummy dispensing is not performed, for example, execution of the determination program P2 is terminated, and processing of the next lot R2 is started. In this way, every time the processing of one lot is completed, the main control unit 78 executes the determination program P2, and it is determined whether or not the above conditions (1) to (3) are satisfied. When one of the conditions is satisfied, dummy dispensing is performed. When all the conditions are not satisfied, dummy dispensing is not performed.
[0055]
According to the present embodiment, since dummy dispensing is performed only when any one of the conditions (1) to (3) is satisfied, dummy dispensing is performed as compared with the conventional case where dummy dispensing is performed each time a lot is changed. The number of times can be reduced. Thereby, the consumption of the resist solution can be reduced. When the type of the resist solution is changed between lot processings, dummy dispensing is performed. For example, the resist solution remains in the resist solution supply nozzles 60 and 61 and the supply pipes 70 and 71 that are not used in the previous lot processing. The deteriorated resist solution can be discharged. As a result, it is possible to prevent the altered resist solution from being supplied onto the wafer W.
[0056]
Also, the allowable time T after the previous lot processing is completed._MDummy dispensing is also performed when the time elapses. In other words, dummy dispensing is performed even when there is time before the next lot processing is started and the resist solution remaining in the resist solution supply nozzles 60 and 61 and the supply pipes 70 and 71 deteriorates. Thereby, it is possible to prevent the deteriorated resist solution from being discharged onto the wafer W. Further, the lot processing number N since the dummy dispensing was performed before is the allowable lot processing number N._MSince the dummy dispensing is performed even when the pressure exceeds the value, for example, bubbles gradually accumulated in the pumps 74 and 75 can be eliminated so that the bubbles are not mixed in the resist solution during processing. For example, when one lot is usually a processing of 25 wafers W, and a lot having 12 wafers or less is included in the continuous lot processing, the lot of 12 or less wafers is included. May be counted as 1/2 lot.
[0057]
In this embodiment, the count of the lot processing number N is reset every time dummy dispensing is performed. As a result, the conditions (1) and (2) are not continuously satisfied, and the number of lot processing N Is the number of allowed lots N_MOnly when the value exceeds, condition (3) is satisfied. Accordingly, the dummy dispense is not performed under the condition (3) immediately after the dummy dispense is performed according to the condition (1), and the number of dummy dispenses can be reduced.
[0058]
Since dummy dispensing is performed at the start of the first lot processing, processing can be performed using a desired resist solution from the first lot processing.
[0059]
The resist solution supply nozzles described in the above embodiment are two systems, but the number is not limited to this, and an arbitrary number (plural) can be selected.
[0060]
In the above embodiment, the condition (1) is that the type of the resist solution is changed between lots. However, the condition (1) is the number of rotations of the wafer W at a predetermined step in the resist coating process between lots. May be changed.
[0061]
For example, as shown in FIG. 8, the resist coating process is performed in three steps, for example, a step S1 in which the wafer W is rotated at a first rotational speed R1, for example, 2000 rpm, and the wafer surface temperature is leveled, and a second rotational speed R2, For example, a resist solution is dropped on the wafer W rotated at 3500 rpm and a resist film is formed on the wafer W, and the wafer W is rotated at the third rotation speed R3, eg 2500 rpm, on the wafer W. Step S3 in which the resist film is stabilized and the resist film is further dried. For example, the condition (1) may be that the second rotation speed R2 in step S2 in the resist coating process is changed between lots. This step 2 involves the diffusion of the resist solution on the surface of the wafer W, and the rotational speed R2 is determined by the viscosity of the resist solution. Different resist solutions have different resist solution viscosities and different rotation speeds R2. Therefore, the determination target of the condition (1) is not set as the resist solution type, and the rotation speed R2 in step 2 of the resist coating process is Substantially the same effect can be obtained. Instead of step S2, the rotational speeds R1 and R3 of the other steps S1 and S3 may be determined as the target of the condition (1).
[0062]
In addition, the allowable time T of the condition (2)_MMay be appropriately determined according to the viscosity of the resist solution used, the type of solvent contained in the resist solution, the photosensitive agent component, and the like. For example, the deterioration times, drying times, and the like of a plurality of resist solutions are obtained by experiments, and the appropriate permissible times of the resist solutions are calculated in advance from the deterioration times. The appropriate permissible time is stored in, for example, the main control unit 78, and when the processing program P1 is assembled, the one having the shortest appropriate permissible time among a plurality of resist solutions used in the processing program. To allow time T_MIs set in the determination program P2. Thus, the allowable time T depends on the type of resist solution._MTherefore, regardless of which resist solution is used, dummy dispensing can be performed at an appropriate timing, and the deteriorated resist solution can be prevented from being discharged onto the wafer W.
[0063]
In addition, the allowable lot processing number N of the above condition (3)_MAlternatively, it may be determined according to the type of resist solution such as the viscosity of the resist solution used and the type of solvent contained in the resist solution. Also in this case, for example, a correlation between various resist solutions and the stain at the tip of the resist solution supply nozzle is obtained through experiments and the number of appropriate allowable lots in each resist solution is calculated in advance from the correlation. For example, the appropriate allowable lot processing number is stored in the main control unit 78, and when the processing program P1 is assembled, the most appropriate allowable lot processing number among a plurality of types of resist solutions used in the processing is prepared. Allowable lot processing number N with less_MIs set in the determination program P2. By doing this, the appropriate number of allowed lots N in each case depends on the type of resist solution used._MAnd dummy dispensing is performed at an appropriate timing.
[0064]
In the above embodiment, the number of lots processed after the previous dummy dispensing is performed under condition (3) is the number of allowed lots processed N_MHowever, the number of processed wafers W may be used instead of the number of processed lots. At this time, the condition {circle around (3)} is that, for example, the number of processed wafers after the previous dummy dispense is performed exceeds the allowable number of processed sheets. In this case, the number of processed wafers is counted by the processing number measurement function, and dummy dispensing is performed when any one of the conditions (1) to (3) is satisfied. The count of the number of processed wafers is reset each time a dummy dispense is performed.
[0065]
In the above embodiment, conditions (1) to (3) are imposed as the conditions for performing dummy dispensing. However, the type of resist solution is changed between conditions (1) and (2), that is, between the lot processes before and after. Time allowed after the previous lot is completed_MDummy dispensing may be performed when any of the conditions for the elapse of time is satisfied. Even in such a case, the type of the resist solution is changed or the allowable time T_MSince the dummy dispense is not performed unless the time elapses, the number of dummy dispenses can be reduced. On the other hand, since the resist solution deteriorated by the dummy dispensing is not supplied to the wafer W when necessary, the resist coating process can be appropriately performed.
[0066]
Furthermore, the conditions (1) and (3), that is, the type of resist solution is changed, and the number of lots processed after the last dummy dispense is N_MThe dummy dispensing may be performed when any one of the conditions is exceeded. Even in such a case, the type of the resist solution is changed, or the number of lot processing N> the number of allowable lot processing N_MUnless this occurs, dummy dispensing is not performed, so that the resist solution consumption can be reduced accordingly. Note that dummy dispensing may be performed only when condition (1), that is, when the type of resist solution is changed between preceding and following lot processing, and even in this case, the number of times of dummy dispensing can be reduced compared to the conventional case. Therefore, the consumption of the resist solution can be reduced.
[0067]
As shown in FIG. 9, the cleaning tank 90 in the resist coating apparatus 17 includes, for example, a sealable casing 90a and cleaning liquid ejection nozzles 91 and 92 for ejecting the cleaning liquid to the resist liquid supply nozzles 60 and 61, respectively. May be. Insertion openings 93 and 94 for inserting the resist solution supply nozzles 60 and 61 into the housing 90a are provided on the upper surface of the housing 90a. A cleaning liquid supply pipe 95 that supplies cleaning liquid into the casing 90a and a discharge pipe 96 that drains the cleaning liquid and the like in the casing 90a are provided on the lower surface of the casing 90a. A predetermined amount, for example, 5 to 20 cc of cleaning liquid is stored in the lower part of the cleaning tank 90, a volatile atmosphere of the cleaning liquid is formed in the upper part of the cleaning tank 90, and the resist liquid supply nozzles 60 and 61 are provided in the volatile atmosphere. Accommodate. By doing so, the tip portions of the resist solution supply nozzles 60 and 61 are exposed to the volatile atmosphere of the cleaning solution during standby, and drying of the resist solution adhering to the tip portions of the resist solution supply nozzles 60 and 61 can be suppressed. Further, for example, immediately before the dummy dispensing is performed, the cleaning liquid is ejected from the cleaning liquid ejection nozzles 91 and 92 to the resist liquid supply nozzles 60 and 61 that are waiting, and adheres to the tip portions of the resist liquid supply nozzles 60 and 61. You may make it wash | clean and dissolve the resist solution etc. which are carried out. Further, after the dummy dispensing is performed thereafter, the cleaning liquid in the cleaning tank 90 is discharged from the discharge pipe 96, a new cleaning liquid is supplied from the cleaning liquid supply pipe 95, and the cleaning liquid in the cleaning tank 90 is replaced. Also good. By doing so, the cleaning liquid contaminated with the dummy dispense can be replaced with a new cleaning liquid.
[0068]
In the above embodiment, the present invention is applied to a processing method for supplying a resist solution to the wafer W. However, the present invention forms another processing solution, for example, a developing solution, a cleaning solution, and an interlayer insulating film. The present invention can also be applied to a processing method for supplying a coating liquid or the like to the wafer W. The present invention can also be applied to processing methods for substrates other than the wafer W, such as LCD substrates, mask substrates, and reticle substrates.
[0069]
【The invention's effect】
According to the present invention, since the number of dummy dispenses can be reduced, the amount of processing liquid consumed can be reduced and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a plan view showing an outline of a configuration of a coating and developing treatment system in the present embodiment.
FIG. 2 is a front view of the coating and developing treatment system of FIG.
FIG. 3 is a rear view of the coating and developing treatment system of FIG. 1;
FIG. 4 is an explanatory view of a longitudinal section showing an outline of the configuration of a resist coating apparatus.
FIG. 5 is an explanatory diagram of a transverse section showing an outline of a configuration of a resist coating apparatus.
FIG. 6 is an explanatory view schematically showing a supply mechanism of a resist solution supply nozzle.
FIG. 7 is an explanatory diagram showing a processing flow between lot processing.
FIG. 8 is a table showing the number of wafer rotations in each step of the resist coating process.
FIG. 9 is an explanatory view of a longitudinal section showing another configuration example of the cleaning tank.
[Explanation of symbols]
1 Coating and developing treatment system
17 resist coating equipment
60, 61 Resist liquid supply nozzle
78 Main control unit
P2 judgment program
W wafer

Claims (3)

A processing method for sequentially performing a substrate processing for supplying a processing liquid to a substrate on a plurality of substrates,
A process of performing a dummy dispensing of the processing liquid at the break of the substrate lot,
The process of performing the dummy dispensing is based on the condition that the type of processing solution to be supplied is changed between lots or that processing of a predetermined number of lots has been completed since the previous dummy dispensing was performed. Only if it meets,
The number of lot processes that do not require dummy dispensing is determined for each of a plurality of types of processing solutions, and the smallest number of lot processes is set as the predetermined number of lot processes. Processing method. A processing method for sequentially performing a substrate processing for supplying a processing liquid to a substrate on a plurality of substrates,
A process of performing a dummy dispensing of the processing liquid at the break of the substrate lot,
The process of performing the dummy dispensing is performed by changing the type of the processing solution between lots, when a predetermined time has elapsed since the processing of the previous lot was completed, or a predetermined number of times after the previous dummy dispensing was performed. Only if one of the following conditions has been met,
The number of lot processes that do not require dummy dispensing is determined for each of a plurality of types of processing solutions, and the smallest number of lot processes is set as the predetermined number of lot processes. Processing method. The number of lots processed to recognize the predetermined number of conditions is counted,
  The processing method according to claim 1, wherein the count of the number of processed lots is reset every time the dummy dispensing is performed.

Images