JP3625120B2 - Substrate processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, a thin plate-like substrate (hereinafter simply referred to as “substrate”) such as a semiconductor substrate, a liquid crystal glass substrate, a photomask glass substrate, and an optical disk substrate is immersed in a processing solution to wash or etch the substrate surface. The present invention relates to a substrate processing apparatus that performs various processes.
[0002]
[Prior art]
Conventionally, the substrate processing apparatus as described above includes a chemical solution tank for storing a chemical solution and a washing tank for storing pure water. Then, according to a predetermined procedure, a plurality of sets of substrates (hereinafter referred to as “lots”) are circulated and transferred to each processing tank, and the substrates are immersed for a predetermined processing time in each processing tank at the transfer destination. The process achieves a series of substrate treatments such as removing contaminants on the substrate surface, etching the oxide film on the substrate surface, and stripping the resist film.
[0003]
By the way, liquid chemicals have a liquid life depending on their types. In the present specification, “liquid life” means an upper limit time during which a chemical solution can be used after being supplied to the chemical solution tank, or an upper limit number of times the substrate can be immersed in the chemical solution. When immersion treatment is performed using the chemical solution after reaching the liquid life, processing failure may occur, so when the chemical solution in the chemical tank reaches the liquid life, a series of substrate processing is temporarily stopped, After the chemical solution that has reached the end of its life is drained and a new chemical solution is supplied, that is, after the chemical solution is replaced, the processing is resumed.
[0004]
[Problems to be solved by the invention]
In the chemical replacement, not only the chemical solution that has reached the end of its life is drained, but then a new chemical solution is supplied, and the chemical tank is cleaned after draining, and after the new chemical solution is supplied, the temperature is adjusted to a temperature suitable for substrate processing. Therefore, a replacement time of about 1 hour is required. Since the state where the substrate processing is interrupted continues during the chemical exchange, a reduction in the processing efficiency of the substrate processing apparatus is inevitable. Especially when the liquid life is short (for example, NH ₄ OH / H ₂ O ₂ / H ₂ O solution containing volatile components), the chemical efficiency must be changed frequently, resulting in a significant decrease in processing efficiency. It becomes.
[0005]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a substrate processing apparatus capable of improving the processing efficiency even when a chemical solution having a short liquid lifetime is used.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a first aspect of the present invention provides a substrate processing apparatus for performing an immersion process on a substrate, (a) storing a chemical solution and performing an immersion process on the substrate in the chemical solution; b) a chemical exchange means for exchanging part or all of the chemical, and (c) Short rather part replacement after or following the and the immersion treatment time the chemical reaches the service life is the time or substrate immersion times to do some exchange row after all the liquid exchange of the chemical than the liquid life The chemical solution exchange means is configured to exchange a part of the chemical liquid when it is not, and when the chemical liquid reaches the end of its life, the chemical liquid exchange means exchanges all of the chemical liquid.
[0007]
Further, the invention of claim 2 is the substrate processing apparatus according to the invention of claim 1, wherein (b-1) a draining means for draining a part of the chemical liquid; and (b-2) ) Replenishment means for replenishing a new chemical solution, and when the chemical solution is partially exchanged in the exchange control means, the drainage means drains a part of the chemical solution, and then the replenishment The means is replenished with the same amount of chemical as the amount of drainage.
[0008]
The invention according to claim 3 is the substrate processing apparatus according to claim 1 or 2, wherein (1) the amount of replacement liquid for partial replacement, (2) the number of times of partial replacement, (3) The apparatus further includes setting means capable of setting and inputting at least one of the service life.
[0009]
According to a fourth aspect of the present invention, in the substrate processing apparatus according to the third aspect of the present invention, the setting means allows the setting means to independently determine the amount of the replacement liquid and the service life in each of the partial replacements. Setting input is possible.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0011]
A. Overall schematic configuration of substrate processing apparatus:
First, the overall configuration of the substrate processing apparatus according to the present invention will be described. FIG. 1 is a schematic front view showing an example of a substrate processing apparatus according to the present invention. The substrate processing apparatus 100 includes chemical baths CB1 and CB2, washing baths WB1, WB2, and FR, a drying unit SD, and a substrate transport robot TR that transports a substrate. In addition, the substrate processing apparatus 100 includes, at both ends, a loader unit LD that mounts a cassette 20 that stores unprocessed substrates W and an unloader unit ULD that mounts a cassette 20 that stores processed substrates W. It has.
[0012]
The chemical tanks CB1 and CB2 are tanks that can store chemical liquids such as sulfuric acid, ammonia, hydrochloric acid, hydrofluoric acid, hydrogen peroxide, or a mixture thereof, and are processing tanks for performing an etching process on the substrate W. is there. The washing tanks WB1 and WB2 are treatment tanks that store pure water and wash the chemical solution attached to the substrate W. The washing tank FR is also a washing treatment tank that contains pure water, but is mainly used for finishing washing. Further, the drying unit SD is a processing unit that removes and dries water droplets attached to the substrate W while rotating the substrate W.
[0013]
The substrate transfer robot TR is movable in the horizontal direction and the vertical direction, pays out an unprocessed lot from the loader unit LD, circulates and transfers the lot between the processing tanks according to a predetermined processing procedure, and has already been processed. It is a robot that passes a lot to the unloader unit ULD. The substrate transfer robot TR includes a pair of hands 11 that can be freely opened and closed, and the hand 11 is provided with a plurality of grooves for holding the substrate W in parallel at a constant pitch (illustrated). (Omitted), the lot is held by the plurality of grooves. When the substrate transport robot TR receives a lot from the loader unit LD, the pair of hands 11 of the substrate transport robot TR grips the lot lifted from the cassette 20 by a holder (not shown) provided below the cassette 20. Is done by doing. Also, when a lot is delivered to the unloader unit ULD, contrary to the above, the lot is delivered from the hand 11 to a holder (not shown), and when the holder is lowered, the lot is stored in the cassette 20. The The example shown here is a system in which a lot is taken out from the cassette 20 and directly held and transferred by the substrate transfer robot TR. However, the substrate transfer robot TR holds the entire cassette 20 and the lot. It may be a so-called cassette conveyance type apparatus.
[0014]
B. Control mechanism of substrate processing equipment:
Next, a control mechanism of the substrate processing apparatus 100 will be described. FIG. 2 is a functional block diagram for explaining a control mechanism of the substrate processing apparatus 100. The substrate processing apparatus 100 incorporates a desktop computer 30, and an operator can give a command to the apparatus via the desktop computer 30 and set a processing pattern and processing conditions.
[0015]
The desktop computer 30 includes a CPU 31 as a main body, a ROM 32 as a read-only memory, a RAM 33 as a readable / writable memory, a magnetic disk 34 for storing control software and data, and an accompanying input. Communication that communicates with an input / output port 35 that is an interface with an output device, a network port 36 that is an interface with an apparatus that directly controls the substrate processing apparatus 100, a host computer provided outside the substrate processing apparatus 100, and the like. Port 37. Further, the desktop computer 30 is provided with a display 38 and a keyboard 39 via an input / output port 35, and an operator inputs commands and parameters from the keyboard 39 while checking the display 38. can do. Then, the operator sets and inputs conditions for partial replacement of the chemical solution from the keyboard 39, which will be described later.
[0016]
The command input to the desktop computer 30 is processed based on processing software, and is transmitted from the desktop computer 30 to the master controller 40 and the tank controller 50 via the network port 36 as necessary. The master controller 40 controls the operation of the substrate transport robot TR (see FIG. 1). Further, the tank controller 50 transmits commands to a chemical liquid draining means 51, a liquid level meter 52, a chemical liquid supply means 53, and the like, which will be described later, and controls pouring / draining into each processing tank. Furthermore, the tank controller 50 includes a timer 56 and a counter 57, which have a function of measuring the usage time of the chemical solution and the number of times the substrate is immersed in the chemical solution.
[0017]
C. Composition of chemical tank:
Next, the configuration of the chemical bath CB1 provided in the substrate processing apparatus 100 will be described. In addition, although the following description is about the chemical | medical solution tank CB1, it is the same also about the chemical | medical solution tank CB2.
[0018]
FIG. 3 is a conceptual diagram illustrating the configuration of the chemical tank CB1 of the substrate processing apparatus 100. The chemical tank CB1 includes an inner tank 60, an outer tank 65, a bat 68, and a pouring / draining mechanism associated therewith.
[0019]
The inner tank 60 is a processing tank that stores a chemical solution and performs an etching process using the chemical solution on the immersed substrate W. The outer tank 65 is a tank for collecting the chemical liquid overflowing from the inner tank 60. The chemical liquid overflowing the outer tank 65 is circulated to the inner tank 60 by the circulation pump 70 and purified by the circulation filter 71 in the path.
[0020]
Further, a chemical solution can be supplied from the chemical solution supply means 53 to the inner tank 60. The chemical liquid supply is performed by supplying the chemical liquid directly from above the inner tank 60 into the inner tank 60, but is not limited to this. For example, in the circulation path from the outer tank 65 to the inner tank 60. You may make it supply a new chemical | medical solution to the outer tank 65 in the state which operated the circulation pump 70. FIG.
[0021]
The amount of the chemical stored in the inner tank 60 can be measured by the liquid level meter 52. The liquid level meter 52 is a device that releases nitrogen gas into the inner tank 60 and measures the chemical liquid level (the liquid level of the chemical liquid in the inner tank 60) from the pressure. Note that the chemical level measurement in the inner tank 60 is not limited to the liquid level meter 52, and known means such as a liquid sensor installed on the inner wall surface of the inner tank 60 can be employed.
[0022]
The bat 68 is a container for collecting the chemical liquid that has further overflowed from the inner tank 60 and the outer tank 65.
[0023]
The chemical liquid stored in the inner tank 60, the outer tank 65, and the bat 68 can be drained by the chemical liquid draining means 51 via the air valves 73, 72, 74 for drain, respectively. The operation of the chemical liquid drain means 51, the liquid level meter 52, the chemical liquid supply means 53, the circulation pump 70, and the air valves 72, 73, 74 shown in FIG. 3 are all controlled by the tank controller 50 (see FIG. 2). ing.
[0024]
When processing is performed in the chemical solution tank CB1 shown in FIG. 3, first, the chemical solution is supplied from the chemical solution supply means 53, and a predetermined amount of liquid necessary for the immersion treatment is stored in the inner tank 60 and the outer tank 65, so that the chemical solution is stored. After the supply is stopped, the substrate W is immersed in the chemical solution in the inner tank 60, and the processing is started. When the immersion treatment for the substrate W is performed regularly, the air valves 72, 73, 74 are closed, and the circulation of the chemical solution by the circulation pump 70 is performed. That is, in the steady state of the immersion treatment, the total amount of the chemical solution is constant, and the overflowing chemical solution out of the treatment chemical solution in the inner tank 60 is collected in the outer tank 65 and circulated through the circulation pump 70. After purification by the filter 71, the operation of supplying the inner tank 60 again is repeated.
[0025]
Next, the chemical solution exchange operation will be described. In the substrate processing apparatus 100 according to the present invention, two types of chemical liquid exchange, that is, “all liquid exchange” and “partial exchange” of the chemical liquid are performed. “Whole liquid replacement” is the same as the conventional chemical liquid replacement, and after all the chemical liquid stored in the inner tank 60 and the outer tank 65 is drained through the air valves 72 and 73, respectively, A new chemical solution is supplied from the chemical solution supply means 53, and a predetermined amount of liquid necessary for the immersion treatment is stored in the inner tank 60 and the outer tank 65. At this time, tank cleaning and chemical liquid temperature control are also performed by a cleaning unit and a temperature control unit (not shown).
[0026]
On the other hand, the “partial replacement” is a chemical replacement for exchanging a part of a predetermined amount of liquid necessary for the dipping process stored in the inner tank 60 and the outer tank 65. That is, after a part of the chemical solution stored in the inner tank 60 and the outer tank 65 is drained through one or both of the air valve 72 and the air valve 73, the same amount of the chemical liquid is drained. Is replenished from the chemical solution supply means 53. At this time, the discharged liquid amount and the replenished liquid amount are monitored by the liquid level meter 52.
[0027]
In “all liquid replacement”, since the entire amount of the chemical solution is replaced, the life of the liquid is completely renewed, but the replacement time is long (about 1 hour). On the other hand, in the “partial replacement”, the liquid life is not completely renewed, but the temperature adjustment time can be shortened, and the replacement time is short (about 10 to 15 minutes). In the substrate processing apparatus 100 according to the present invention, these two kinds of liquid exchanges are applied in an appropriate combination, and a chemical liquid exchange processing procedure will be described below.
[0028]
D. Chemical exchange procedure:
FIG. 4 is a flowchart showing a processing procedure for chemical replacement. The chemical exchange procedure is the same in the chemical tank CB1 and the chemical tank CB2. FIG. 5 is a conceptual diagram for explaining the pattern of the chemical solution exchange process. In FIG. 5, the horizontal axis indicates the passage of time, and the vertical axis indicates the total amount of liquid stored in the inner tank 60 and the outer tank 65. FIG. 5A shows a pattern of conventional chemical solution exchange processing, and FIGS. 5B to 5D show chemical solution exchange processing patterns of the substrate processing apparatus according to the present invention.
[0029]
First, initial setting is performed in step S1 of FIG. The initial setting is performed by the operator of the apparatus inputting settings via the keyboard 39 (see FIG. 2). The items to be set here are
(1) Exchange liquid volume for partial replacement,
(2) Number of partial replacements performed between all liquid replacements
(3) Service life of chemicals,
These are the three items. As shown in FIG. 5, the “service life” of a chemical solution is the time from the partial replacement of the chemical solution until the next partial replacement of the chemical solution or the number of times of immersion in the substrate. Set. In addition, the time from the whole liquid exchange to the partial exchange immediately after that or the number of immersions, and the time from the partial exchange immediately before the whole liquid exchange to the whole liquid exchange or the number of immersions are also “service life”.
[0030]
It is not always necessary to set and input all of the above three items. Some of the three items may be set and input, and values given to the apparatus as defaults may be used for the other items. In addition, default values may be used for all items. Furthermore, as shown in FIG. 5 (d), it is also possible as benzalkonium be respectively mutually independently set input of replacement fluid amount and service life in each round of part replacement.
[0031]
By the way, when the number of partial replacements and the service life are set as described above, the time from the total liquid replacement to the total liquid replacement or the number of times of substrate immersion, that is, a new liquid life is automatically determined based on them. Will be. As is clear from the comparison of the pattern of FIG. 5A and the patterns of FIGS. 5B to 5D, incorporating partial replacement into the chemical liquid replacement has the same effect as extending the liquid life. Will have.
[0032]
Returning to FIG. 4, when the initial setting is completed, the process proceeds to step S <b> 2, and it is determined whether or not the chemical solution being used has reached the liquid life. The liquid life here is a new liquid life determined based on the set number of partial replacements and the service life. As a determination target, either the usage time of the chemical solution measured by the timer 56 or the number of times of substrate immersion measured by the counter 57 may be used, or both of them may be used (the use described below) The same applies to the determination of the life (step S3). Note that all subsequent steps are judged by the tank controller 50 and a processing command is given.
[0033]
If it is determined in step S2 that the liquid life has been reached, the process proceeds to step S7 where all liquids are replaced. The whole liquid exchange operation is as described above. On the other hand, if the liquid life has not been reached, the process proceeds to step S3, and it is determined whether or not the chemical liquid being used has reached the service life. If the chemical solution being used has reached the service life, it is determined whether or not the substrate W is present in the chemical solution tank (step S4). When the substrate W is present in the chemical bath, the process proceeds to the next step S5 after waiting for the immersion process of the substrate W to end.
[0034]
The chemical solution is partially exchanged by the processing in both step S5 and step S6. That is, as described above, after part of the chemical stored in the chemical tank is drained (step S5), the same amount of new chemical as the drained is replenished (step S6).
[0035]
The reason why part of the chemical solution is not exchanged when the substrate W is present in the chemical solution tank is to prevent a portion of the substrate W from being exposed to the air or uneven etching due to a temperature change of the chemical solution. Also, after draining a part of the chemical solution, replenishing the same amount of new chemical solution as drained is the opposite, that is, deterioration of the liquid quality due to replacement rather than draining after adding a new chemical solution This is because the recovery effect is great.
[0036]
When the all liquid replacement (step S7) is completed, when the partial replacement (steps S5 and S6) is completed, or when the chemical solution being used has not reached the liquid life or the service life, the process proceeds to step S8. It is determined whether or not a series of substrate processing has been completed. If not, the process returns to step S2. Therefore, the chemical exchange process procedure in steps S2 to S7 is repeated until a series of substrate processing in the substrate processing apparatus 100 is completed.
[0037]
As described above, in the substrate processing apparatus 100 according to the present embodiment, the amount of replacement liquid for partial replacement, the number of partial replacements, and the service life of chemicals can be arbitrarily set. Since each can also be set independently, various chemical solution exchange processing patterns as shown in FIGS. 5B to 5D are possible depending on the type of chemical solution and the mode of substrate immersion treatment. In addition, what was illustrated is an illustration and it is needless to say that various other patterns are possible. And these chemical | medical solution exchange process patterns will be performed according to the procedure shown in FIG.
[0038]
Further, as shown in FIGS. 5B to 5D, the same effect as that of extending the liquid life can be obtained by incorporating partial replacement with a short replacement time into the chemical liquid replacement. The number of long liquid replacements is reduced, and the processing efficiency of the entire apparatus is improved. Of course, the immersion process in the chemical solution cannot be performed even during the partial replacement, but the time required for the partial replacement is short and can be absorbed at the lot payout interval. That is, in the substrate processing apparatus 100, since the processing time in the drying unit SD is relatively long, lots are paid out from the loader unit LD in synchronization with the processing interval of the drying unit SD. The partial exchange ends. Therefore, the processing efficiency of the entire apparatus is not reduced by partial replacement.
[0039]
The embodiment of the present invention has been described above, but the present invention is not limited to the above example. For example, the substrate processing apparatus 100 in the above embodiment is an apparatus that processes the substrate W in lot units. However, this may be a single-wafer type substrate processing apparatus that processes one by one.
[0040]
【The invention's effect】
As described above, according to the first aspect of the present invention, the chemical tank for storing the chemical and immersing the substrate in the chemical, the chemical exchange means for exchanging a part or all of the chemical, and the liquid lifetime when the and the immersion treatment time chemical reaches the service life is the time or substrate immersion times to perform some replacement to the next part replacement or after all the liquid after the replacement of the short rather chemical it is not performed than In addition, the chemical solution exchange means can exchange part of the chemical liquid, and when the chemical liquid reaches the end of its life, the chemical liquid exchange means has an exchange control means for exchanging the entire liquid. Thus, even when a chemical solution having a short liquid life is used, the processing efficiency of the entire apparatus is improved. In addition, part of the substrate is not exchanged during the immersion treatment, so that it is possible to prevent unevenness in etching due to exposure of part of the substrate to the air and temperature change of the chemical solution.
[0041]
According to the second aspect of the present invention, when a part of the chemical solution is exchanged, a part of the chemical solution is drained by the draining unit, and then the same amount of the chemical solution as the amount of drainage is supplied to the supplementing unit Since the liquid is replenished, the effect of recovering the deterioration of the liquid quality due to the replacement can be increased rather than draining after adding a new chemical.
[0042]
According to the inventions of claim 3 and claim 4, at least one of (1) the amount of replacement liquid for partial replacement, (2) the number of partial replacements, and (3) service life is set and input. Since possible setting means is further provided, it is possible to set an appropriate chemical exchange process pattern according to the type of chemical and the manner of substrate immersion treatment.
[Brief description of the drawings]
FIG. 1 is a schematic front view showing an example of a substrate processing apparatus according to the present invention.
2 is a functional block diagram for explaining a control mechanism of the substrate processing apparatus of FIG. 1; FIG.
3 is a conceptual diagram illustrating the configuration of a chemical tank in the substrate processing apparatus of FIG.
FIG. 4 is a flowchart showing a processing procedure for chemical replacement.
FIG. 5 is a conceptual diagram for explaining a pattern of chemical solution exchange processing.
[Explanation of symbols]
39 Keyboard 50 Tank controller 51 Chemical liquid drain means 52 Liquid level meter 53 Chemical liquid supply means 60 Inner tank 65 Outer tanks 72, 73, 74 Air valve 100 Substrate processing apparatus CB1, CB2 Chemical liquid tank

Claims (4)

In a substrate processing apparatus that performs an immersion process on a substrate,
(a) storing a chemical solution, and a chemical bath for immersing the substrate in the chemical solution;
(b) chemical solution exchange means for exchanging part or all of the chemical solution;
(c) Short rather part replacement after or following the and the immersion treatment time the chemical reaches the service life is the time or substrate immersion times to do some exchange row after all the liquid exchange of the chemical than the liquid life An exchange control means for causing the chemical liquid exchange means to exchange a part of the chemical liquid when it is not, and for causing the chemical liquid exchange means to exchange all the chemical liquid when the chemical liquid reaches a liquid life;
A substrate processing apparatus comprising: The substrate processing apparatus according to claim 1,
The chemical solution exchange means is
(b-1) drainage means for draining a part of the chemical solution;
(b-2) replenishment means for replenishing new chemicals;
With
The replacement control means, when exchanging a part of the chemical solution, causes the drainage means to drain a part of the chemical solution, and then supplies the replenishment means with the same amount of the chemical solution as the amount of the drainage liquid. A substrate processing apparatus which is replenished. In the substrate processing apparatus of Claim 1 or Claim 2,
(1) The amount of replacement liquid for the partial replacement,
(2) The number of partial exchanges,
(3) said service life,
A substrate processing apparatus further comprising setting means capable of setting and inputting at least one of them. The substrate processing apparatus according to claim 3, wherein
The setting means includes
A substrate processing apparatus capable of setting and inputting each of the exchange liquid amount and the service life at each partial replacement.

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