JPH10261610A - Substrate processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate processor which can improve a processing efficiency, even if chemicals of short life times is used. SOLUTION: Before processing a substrate, a quantity of chemicals to be replaced in a partial replacement, the number of times of the partial replacements, and a usage life of the chemicals are preliminarily set. These values can be set to any value. Then, a dipping treatment of a substrate is started and, when the chemicals reaches the end of the usage life, the chemicals is partially replaced. The partial replacement of chemicals is conducted while no substrate exists in a chemicals tub. After a part of the chemicals is removed out of the tub, the same quantity of new chemicals as that of the removed chancels is out into the tub. After the partial replacements are repeated for the set number of times, a total replacement is conducted to replace the entire chemicals with new chemicals. By including in the replacement of chemicals, partial replacements which require a short time for replacement, the number of times of the total replacements which require a long time for replacement is decreased and therefore, even if chemicals of a short life is used, a processing efficiency as an overall equipment can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate made by immersing a thin plate-like substrate (hereinafter simply referred to as "substrate") such as a semiconductor substrate, a liquid crystal glass substrate, a glass substrate for a photomask and a substrate for an optical disk in a processing liquid. The present invention relates to a substrate processing apparatus that performs various processes such as cleaning and etching on a surface.

[0002]

2. Description of the Related Art Conventionally, the above-described substrate processing apparatus has a chemical solution tank for storing a chemical solution and a washing tank for storing pure water. Then, according to a predetermined procedure, a set of a plurality of substrates (hereinafter, referred to as a “lot”) is circulated and transported to each processing tank, and the plurality of substrates are immersed for a predetermined processing time in each processing tank at the destination. Through the process, a series of substrate treatments of removing contaminants on the substrate surface, etching an oxide film on the substrate surface, and stripping a resist film is achieved.

[0003] A chemical solution has a liquid life depending on the type of the chemical solution. In this specification, the term “liquid life” means an upper limit time in which the chemical solution can be used after supplying the chemical solution to the chemical solution tank or an upper limit number of times the substrate can be immersed in the chemical solution. If the immersion process is performed using the chemical after the life of the liquid, the processing may be defective.If the chemical in the chemical tank reaches the life of the liquid, a series of substrate processing is temporarily stopped. After the chemical liquid which has reached the liquid life is drained and a new chemical liquid is supplied, that is, after the chemical liquid is replaced, the processing is restarted.

[0004]

The replacement of a chemical solution is not merely a matter of draining a chemical solution whose life has expired and then supplying a new chemical solution, but also cleaning the inside of a chemical solution tank after drainage and after supplying a new chemical solution. Since it is necessary to adjust the temperature to a temperature suitable for substrate processing,
A replacement time of about one hour is required. Since the substrate processing is interrupted during the chemical exchange, a reduction in the processing efficiency of the substrate processing apparatus is inevitable. Particularly, the liquid life is short (for example, NH ₄ OH / H ₂ O ₂ / H ₂ containing volatile components)
In the case of an O solution or the like, the chemical solution must be frequently exchanged, so that the processing efficiency is significantly reduced.

[0005] The present invention has been made in view of the above problems, and even when a chemical solution having a short liquid life is used,
An object of the present invention is to provide a substrate processing apparatus capable of improving processing efficiency.

[0006]

According to a first aspect of the present invention, there is provided a substrate processing apparatus for performing immersion processing on a substrate, comprising: (a) storing a chemical solution; A chemical tank for performing immersion processing, (b) a chemical liquid exchange means for replacing a part of the chemical liquid, and (c) the immersion processing is performed when the chemical liquid reaches a service life shorter than the liquid life. Exchange control means for causing the chemical liquid exchange means to partially exchange the chemical liquid when not in operation.

According to a second aspect of the present invention, in the substrate processing apparatus according to the first aspect of the present invention, (b)
-1) draining means for draining a part of the chemical liquid, and (b-2) replenishing means for replenishing a new chemical liquid, the exchange control means, the drainage means out of the chemical liquid After partially draining the liquid, the replenishing means is replenished with the same amount of the chemical as the amount of the drained liquid.

According to a third aspect of the present invention, there is provided the substrate processing apparatus according to the first or second aspect of the present invention, wherein (1) an exchange liquid amount of the partial exchange, (2) a number of times of the partial exchange, (3) There is further provided a setting means capable of setting and inputting at least one of the service life.

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 is configured to reciprocate the exchange liquid amount and the service life at each time of the partial exchange. Can be set and input independently.

[0010]

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

A. Overall schematic configuration of substrate processing apparatus:
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 the substrate processing apparatus according to the present invention. The substrate processing apparatus 100 includes a chemical solution tank C
B1, CB2, washing tanks WB1, WB2, FR, a drying unit SD, and a substrate transport robot TR for transporting substrates. Further, the substrate processing apparatus 100 has, at both ends thereof,
A loader section LD on which a cassette 20 containing unprocessed substrates W is placed and a cassette 2 on which processed wafers W are stored
And an unloader unit ULD on which the 0 is placed.

The chemical tanks CB1 and CB2 are tanks capable of storing a chemical such as sulfuric acid, ammonia, hydrochloric acid, hydrofluoric acid, hydrogen peroxide, or a mixture thereof, and are used for performing an etching process on the substrate W. It is a processing tank. The washing tanks WB1 and WB2 are processing tanks that contain pure water and wash chemicals attached to the substrate W. The washing tank FR is also a washing tank containing pure water, and is mainly used for finishing washing. Further, the drying unit SD is a processing unit that removes water droplets attached to the substrate W while rotating the substrate W, and dries.

The substrate transfer robot TR is movable in the horizontal and vertical directions, pays out unprocessed lots from the loader section LD, circulates and transfers the lots among the processing tanks according to a predetermined processing procedure, This robot transfers the processed lot to the unloader unit ULD. The substrate transport robot TR includes a pair of openable and closable hands 11, and a plurality of grooves for holding the substrate W are provided in the hand 11 in parallel at a constant pitch (shown in the figure). (Omitted), lots are held by the plurality of grooves. This substrate transfer robot T
When the R receives the lot from the loader section LD, the pair of hands 11 of the substrate transport robot TR grips the lot raised from the cassette 20 by a holder (not shown) provided below the cassette 20. Will be When transferring the lot to the unloader unit ULD, the lot is transferred from the hand 11 to a holder (not shown), and the lot is stored in the cassette 20 by descending the holder. You. The example shown here is an apparatus of a type in which a lot is taken out from the cassette 20 and the lot is directly gripped and transported by the substrate transport robot TR. May be a so-called cassette transport type device for transporting the paper.

B. Control mechanism of substrate processing apparatus: Next, a control mechanism of the substrate processing apparatus 100 will be described. FIG.
FIG. 3 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. An operator can give commands to the apparatus and set processing patterns and processing conditions via the desktop computer 30.

The desktop computer 30 has a CPU 31 as a main body thereof and a ROM as a read-only memory.
32, a RAM 33 which is a readable and writable memory,
A magnetic disk 34 for storing control software, data, etc., an input / output port 35 as an interface with associated input / output devices, and a network port 36 as an interface with a device that directly controls the substrate processing apparatus 100. A communication port 3 for communicating with a host computer or the like provided outside the substrate processing apparatus 100
7 is provided. The desktop computer 30 is also provided with a display 38 and a keyboard 39 via an input / output port 35.
You can enter commands and parameters from. Then, the operator sets and inputs the conditions for the partial replacement of the chemical solution from the keyboard 39, which will be further described later.

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. Is done. The master controller 40 controls the operation of the substrate transport robot TR (see FIG. 1). The tank controller 50 includes a chemical liquid drain unit 51, a liquid level meter 52, and a chemical liquid supply unit 53, which will be described later.
And the like, and controls the injection and drainage of each processing tank. Further, the tank controller 50 includes a timer 56 and a counter 57, which have a function of measuring the use time of the chemical solution and the number of times the substrate is immersed in the chemical solution.

C. Configuration of Chemical Solution Tank: Next, Substrate Processing Apparatus 1
The configuration of the chemical solution tank CB1 provided in 00 will be described. The following description is for the chemical solution tank CB1, but the same applies to the chemical solution tank CB2.

FIG. 3 shows a chemical solution tank CB of the substrate processing apparatus 100.
1 is a conceptual diagram illustrating the configuration of FIG. The chemical solution tank CB1 includes an inner tank 60, an outer tank 65, a vat 68, and a liquid supply / drainage mechanism associated therewith.

The inner tank 60 is a processing tank for storing a chemical solution and performing an etching process or the like on the immersed substrate W with the chemical solution. The outer tank 65 is a tank for collecting a chemical solution overflowing from the inner tank 60. The chemical liquid overflowing into the outer tank 65 is circulated to the inner tank 60 by the circulation pump 70, and is purified by the circulation filter 71 in the path.

A chemical solution can be supplied to the inner tank 60 from a chemical solution supply means 53. The chemical solution is supplied to the inner tank 60
This is performed by supplying a chemical solution directly into the inner tank 60 from above, but is not limited to this. For example,
A new chemical solution may be supplied into the circulation path from the outer tank 65 to the inner tank 60, or may be supplied to the outer tank 65 while the circulation pump 70 is operating.

The amount of the chemical stored in the inner tank 60 can be measured by a liquid level meter 52. The liquid level meter 52 discharges nitrogen gas into the inner tank 60 and measures the chemical level (the liquid level of the chemical in the inner tank 60) based on the pressure.
Is a device for measuring In addition, the chemical level measurement of the inner tank 60 is not limited to the liquid level meter 52, and any known means such as installing a liquid sensor on the inner wall surface of the inner tank 60 and performing measurement may be employed.

The vat 68 is a container for collecting the chemical liquid overflowing from the inner tank 60 and the outer tank 65.

The inner tank 60, the outer tank 65, and the butt 6
The chemical solution stored in 8 can be drained by the chemical solution draining means 51 via drain air valves 73, 72, 74, respectively. The operations of the chemical liquid discharging means 51, liquid level meter 52, chemical liquid supplying means 53, circulation pump 70 and air valves 72, 73, 74 shown in FIG. 3 are all controlled by the tank controller 50 (see FIG. 2). ing.

When processing is performed in the chemical tank CB1 shown in FIG. 3, first, a chemical is supplied from the chemical supply means 53, and a predetermined amount of liquid necessary for the immersion processing is stored in the inner tank 60 and the outer tank 65. After the supply of the chemical solution is stopped, the substrate W is immersed in the chemical solution in the inner tank 60, and the processing is started. When the immersion process on the substrate W is being performed steadily, the air valves 72, 73, and 74 are closed, and the circulating pump 70 circulates the chemical solution. That is, in the steady state of the immersion process, the total amount of the chemical solution is constant, and the overflowing chemical solution among the processing chemicals in the inner tank 60 is collected in the outer tank 65 and circulated through the circulation pump 70. After being purified by the filter 71, the operation of being supplied to the inner tank 60 again is repeated.

Next, the chemical liquid exchange operation will be described. In the substrate processing apparatus 100 according to the present invention, two kinds of chemical liquid exchanges, that is, “all liquid exchange” and “partial exchange” of chemical liquids are performed. The “exchange of all liquids” is the same as the conventional chemical liquid exchange, and after all the chemical liquids stored in the inner tank 60 and the outer tank 65 are drained through the air valves 72 and 73, respectively, A new chemical liquid is supplied from the chemical liquid supply means 53, and a predetermined liquid amount required for the immersion treatment is stored in the inner tank 60 and the outer tank 65. At this time, cleaning of the tank and temperature control of the chemical solution are also performed by cleaning means and temperature control means (not shown).

On the other hand, "partially exchange" is a chemical exchange in which a part of a predetermined amount of liquid stored in the inner tank 60 and the outer tank 65 and necessary for the immersion treatment is exchanged. 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 solution as the drained liquid is discharged. Is supplied from the chemical supply means 53. At this time, the amount of drained liquid and the amount of replenished liquid are monitored by the liquid level meter 52.

In the "all liquid exchange", since the entire amount of the chemical liquid is exchanged, the liquid life is completely renewed, but the exchange time is long (about 1 hour). On the other hand, the "partial replacement" does not completely renew the liquid life, but can also shorten the temperature control time, and the replacement time is short (about 10 to 15 minutes). In the substrate processing apparatus 100 according to the present invention, these two types of liquid exchange are appropriately combined and applied, and a processing procedure of chemical exchange will be described below.

D. FIG. 4 is a flowchart showing a processing procedure of chemical solution exchange. The processing procedure of the chemical solution exchange is the same in the chemical solution tank CB1 and the chemical solution tank CB2. FIG. 5 is a conceptual diagram for explaining a pattern of a 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.
FIG. 5A shows a pattern of a conventional chemical exchange process, and FIG.
(B) to (d) are chemical liquid exchange processing patterns of the substrate processing apparatus according to the present invention.

First, initialization is performed in step S1 of FIG. The initial setting is performed by the operator of the apparatus inputting the setting via the keyboard 39 (see FIG. 2). The items to be set here are three items: the amount of liquid exchange in the partial exchange, the number of partial exchanges performed between the entire liquid exchange and the next total liquid exchange, and the service life of the chemical solution. As shown in FIG. 5, the "use life" of a chemical solution is the time from the partial replacement of the chemical solution to the next partial replacement of the chemical solution or the number of times of immersion in the substrate, and the time shorter than the lifetime of the solution or the number of immersion times. Set. The “service life” is also the time or the number of times of immersion from the total liquid exchange to the partial exchange immediately after that, and the time or the number of immersions from the partial exchange to the all liquid exchange immediately before the entire liquid exchange.

It is not always necessary to set and input all of the above three items. Some of the above items may be set and input, and the other items may use values previously given to the apparatus as defaults. . Alternatively, default values may be used for all items. further,
As shown in FIG. 5D, it is also possible to set and input the exchange liquid amount and the service life in each of the partial exchanges independently of each other.

When the number of times of partial replacement and the service life are set as described above, the time from total solution replacement to total solution replacement or the number of times of substrate immersion, that is, the new solution life is automatically set based on these. Will be determined.
As is clear from the comparison between the pattern in FIG. 5A and the patterns in FIGS. 5B to 5D, the incorporation of a partial replacement into the chemical replacement has the same effect as extending the liquid life. Will have.

Returning to FIG. 4, when the initial setting is completed, the process proceeds to step S2, and it is determined whether or not the used chemical liquid has reached the liquid life. The liquid life here is a new liquid life determined based on the set number of times of partial replacement and the service life set above. The object of the determination is the usage time of the chemical solution measured by the timer 56 or the counter 57.
Any of the number of times of immersion of the substrate measured by the above method may be used, or both of them may be used (the same applies to the determination of the service life (step S3) described below). The steps after this are all judged by the tank controller 50, and a processing command is given.

If it is determined in step S2 that the liquid life has expired, the flow advances to step S7 to replace all liquids. The operation of the whole liquid exchange 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 the used chemical liquid has reached the used life. If the used chemical has reached the end of its service life, it is determined whether or not the substrate W is present in the chemical bath (step S4). When the substrate W is present in the chemical solution tank, the process proceeds to the next step S5 after the completion of the immersion processing of the substrate W.

By both the processing in step S5 and the processing in step S6, partial replacement of the chemical solution is executed. That is,
As described above, after a part of the chemical solution stored in the chemical solution tank is drained (step S5), the same amount of new chemical solution as the drained one is replenished (step S6).

The reason why the chemical solution is not partially exchanged when the substrate W is present in the chemical solution tank is to prevent a part of the substrate W from being exposed to the air and to prevent uneven etching due to a temperature change of the chemical solution. is there. In addition, replenishing a part of a chemical solution and then replenishing it with the same amount of new chemical solution 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 effect of the recovery is great.

When the whole liquid exchange (step S7) is completed, when the partial exchange (steps S5 and S6) is completed, or when the chemical solution in use has not reached the liquid life or the service life, the step Proceeding to S8, it is determined whether a series of substrate processing has been completed. If not completed, the process returns to step S2. Therefore, until the series of substrate processing in the substrate processing apparatus 100 is completed, the chemical liquid exchange processing procedure of step S2 to step S7 is repeated.

As described above, the substrate processing apparatus 1 of the present embodiment
In the case of 00, the replacement liquid amount of the partial replacement, the number of times of the partial replacement and the service life of the chemical solution can be arbitrarily set, and the replacement amount and the service life of each partial replacement can also be set independently. Or depending on the mode of the substrate immersion process,
Various chemical liquid exchange processing patterns as shown in FIGS. 5B to 5D become possible. It should be noted that the illustration is an example,
Of course, various other patterns are also possible. FIG. 4 shows the chemical exchange pattern.
Is executed according to the procedure shown in FIG.

As shown in FIGS. 5B to 5D,
By incorporating a partial replacement with a short replacement time into the chemical replacement, the same effect as extending the liquid life can be obtained, and as a result, the number of total liquid replacements with a long replacement time is reduced, and the entire device is The processing efficiency is improved.
Although the immersion process in the chemical solution cannot be performed during the partial replacement, the time required for the partial replacement is short, and the time 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, the lot is discharged from the loader unit LD in synchronization with the processing interval of the drying unit SD. Within, the exchange is partially completed. Therefore, the processing efficiency of the entire apparatus does not decrease due to the partial replacement.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described example. For example, the substrate processing apparatus 100 in the above-described embodiment is an apparatus for processing a substrate W in lot units. But this is 1
It may be a single-wafer-type substrate processing apparatus that processes one by one.

[0040]

As described above, according to the first aspect of the present invention, a chemical solution tank for storing a chemical solution and performing immersion processing on a substrate in the chemical solution, and a chemical solution exchange means for exchanging a part of the chemical solution are provided. When the chemical liquid has reached a service life shorter than the liquid life, and when the immersion processing is not performed, the chemical liquid exchange means has exchange control means for partially exchanging the chemical liquid. The number of times of long total liquid exchange is reduced, and the processing efficiency of the entire apparatus is improved even when a chemical liquid with a short liquid life is used. In addition, since there is no partial replacement during the immersion process, it is possible to prevent exposure of a portion of the substrate to the air and uneven etching due to a change in temperature of the chemical solution.

According to the second aspect of the present invention, after a part of the chemical solution is drained by the drainage unit, the replenishment unit is replenished with the same amount of the chemical solution as the drainage amount. It is possible to increase the effect of liquid quality deterioration recovery by replacement rather than draining after adding a new chemical solution.

Further, according to the third and fourth aspects of the present invention, (1) the amount of liquid exchange for partial exchange, (2) the number of times of partial exchange,
(3) The service life is further provided with a setting means capable of setting and inputting at least one of the service life, so that an appropriate chemical liquid exchange processing pattern can be set according to the type of the chemical liquid and the mode of the substrate immersion processing. Become.

[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.

FIG. 2 is a functional block diagram for explaining a control mechanism of the substrate processing apparatus of FIG.

FIG. 3 is a conceptual diagram illustrating a configuration of a chemical solution tank of the substrate processing apparatus of FIG.

FIG. 4 is a flowchart illustrating a processing procedure for exchanging a chemical solution.

FIG. 5 is a conceptual diagram for explaining a pattern of a chemical solution exchange process.

[Description of Signs] 39 Keyboard 50 Tank controller 51 Chemical liquid drainage unit 52 Liquid level gauge 53 Chemical liquid supply unit 60 Inner tank 65 Outer tank 72, 73, 74 Air valve 100 Substrate processing device CB1, CB2 Chemical tank

Claims (4)

[Claims] 1. A substrate processing apparatus for performing immersion processing on a substrate, comprising: (a) a chemical solution tank for storing a chemical solution and performing immersion processing on the substrate in the chemical solution; and (b) a part of the chemical solution. And (c) causing the chemical exchange unit to partially exchange the chemical when the chemical reaches a service life shorter than the liquid life and when the immersion process is not performed. Exchange control means;
A substrate processing apparatus comprising: 2. The substrate processing apparatus according to claim 1, wherein the chemical liquid exchanging means comprises: (b-1) a liquid discharging means for discharging a part of the chemical liquid; and (b-2) replenishing a new chemical liquid. The replacement control means causes the drainage means to drain a part of the chemical solution, and then causes the replenishment means to refill the same amount of the chemical solution as the amount of the drainage solution. A substrate processing apparatus characterized by the above-mentioned. 3. The substrate processing apparatus according to claim 1, wherein: (1) an exchange liquid amount of the partial exchange; (2) a number of times of the partial exchange; and (3) a service life. A substrate processing apparatus further comprising setting means for setting and inputting at least one of the following. 4. The substrate processing apparatus according to claim 3, wherein said setting means is capable of independently setting and inputting said replacement liquid amount and said service life at each time of said partial replacement. apparatus.