JP3437728B2 - Substrate processing equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of immersing a thin substrate (hereinafter simply referred to as "substrate") such as a semiconductor substrate, a liquid crystal glass substrate, a photomask glass substrate and an optical disc substrate in a treatment liquid. The present invention relates to a substrate processing technique for performing various processing such as cleaning on the surface.

[0002]

2. Description of the Related Art Conventionally, the substrate processing apparatus as described above has a chemical bath for storing a chemical (HF, etc.) and a washing bath for storing pure water. Then, according to a predetermined procedure, a lot (one set of a plurality of substrates) is circulated and transported to each processing tank, and a plurality of steps of dipping the lot for a predetermined processing time in each of the processing tanks at the destination is performed. A series of substrate treatments such as removing contaminants, etching the oxide film on the substrate surface, and peeling the resist film have been achieved.

[0003]

By the way, even in the above substrate processing apparatus, some apparatus trouble may occur. For example, when a substrate transfer robot that circulates and conveys a lot fails, the lot cannot be conveyed between the processing tanks, so that the lot being processed in each processing tank continues to be immersed in the processing liquid. In such a case, the lot immersed in pure water in the washing tank does not cause much problem, but the lot immersed in the chemical solution in the chemical solution tank is subjected to surface treatment more than necessary. In particular, the dipping process in HF-based chemicals is sensitive to the processing time, and if the lot is dipped more than necessary, it will be in an excessively etched state (so-called over-etching), and the lot will be used later. Impossible (hereinafter,
It is called "lot out".

In view of the above problems, the present invention makes the substrate being processed defective (lot out in the case of a lot) even when the substrate cannot be transported due to a trouble of the apparatus. It is an object of the present invention to provide a substrate processing apparatus capable of preventing the above.

[0005]

In order to solve the above problems, the invention of claim 1 uses a plurality of processing tanks for a substrate.
In the substrate processing apparatus for performing the immersion treatment, the (a) chemical solution tank is used to store the chemical solution in the chemical solution and the substrate is immersed in the chemical solution, and (b) pure water is stored to wash the substrate with the pure water.
A washing tank for performing cleaning treatment, (c) pure water supply means for supplying pure water to the chemical solution tank, (d) a space between the chemical solution tank and the washing tank
In a substrate transfer robot for transferring the substrate, based on the timing by (e) comprises a timer and capable of measuring the elapsed time from when the immersion treatment is started in the chemical bath, the timer, the Immersion treatment time in chemical bath
Is a preset processing as the processing time required for the immersion processing
When the time is reached, the board transfer robot
Remove the substrate from the chemical solution tank and place it in the chemical solution tank.
The dipping process is set as above and the dipping process is continued.
Less than or equal to the allowable preset time that can be allowed
If it is found that the above time has been performed, the pure water supply is performed.
Pure water supply from the supply means is started.

According to a second aspect of the present invention, in the substrate processing apparatus according to the first aspect of the invention, (f) a chemical liquid draining means for draining the chemical liquid from the chemical liquid tank is further provided, and the time counting by the timer is performed. Based on the above, the immersion treatment in the chemical solution tank was performed for a time equal to or more than the sum of the preset treatment time as the treatment time required for the immersion treatment and the preset allowable overtime that can be allowed to continue the immersion treatment. If it is found, the chemical solution is once discharged from the chemical solution tank, and then the pure water supply from the pure water supply means is started.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

A. Overall schematic structure 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. This substrate processing apparatus 100 includes a chemical bath C
B1, CB2, water washing tanks WB1, WB2, FR, a drying section SD, and a substrate transfer robot TR for transferring a substrate are provided. In addition, the substrate processing apparatus 100 has
A loader unit (left end in the drawing) for mounting the cassette 20 containing the unprocessed substrates W and an unloader unit (right end in the drawing) for mounting the cassette 20 in which the processed substrates W are stored are provided. There is.

The chemical solution tanks CB1 and CB2 are tanks capable of containing a chemical solution such as sulfuric acid, ammonia, hydrochloric acid, hydrofluoric acid, hydrogen peroxide solution, or a mixture thereof, but in the example considered here, hydrofluoric acid ( It is a processing tank for storing HF) and performing etching processing on the substrate. In addition, the washing tank WB
Reference numerals 1 and WB2 are treatment tanks that contain pure water and clean the HF adhering to the substrate W. Further, the water washing tank FR is also a washing treatment tank that stores pure water, but is mainly used for finishing washing. Further, the drying unit SD is a processing unit that removes water droplets adhering to the substrate W while rotating the substrate W and dries it.

The substrate transfer robot TR is movable in the horizontal and vertical directions, discharges unprocessed lots from the loader section, circulates and transfers the lots among the processing tanks according to a predetermined processing procedure, and performs processing. It is a robot that passes the completed lot to the unloader section. When the substrate transfer robot TR receives a lot from the loader unit, a pair of hands 11 of the substrate transfer robot TR grip the lot lifted from the cassette 20 by a holder (not shown) provided below the cassette 20. Done by. When the lot is transferred to the unloader section, the lot is transferred from the hand 11 to a holder (not shown), and the holder is lowered, so that the lot is stored in the cassette 20. . The example shown here is an apparatus of a system in which a lot is taken out from the cassette 20 and the substrate transport robot TR directly grasps and transports the lot.
It may be a so-called cassette transfer type device in which the substrate transfer robot TR holds 0 and transfers the lot.

B. Control Mechanism of Substrate Processing Apparatus: Next, the control mechanism of the substrate processing apparatus 100 will be described. Figure 2
3 is a functional block diagram for explaining a control mechanism of the substrate processing apparatus 100. FIG. A desktop computer 30 is incorporated in the substrate processing apparatus 100, and an operator can give a command to the apparatus via the desktop computer 30 and set a processing pattern and processing conditions.

The desktop computer 30 has a CPU 31 as its main body and a ROM as a read-only memory.
32, and a RAM 33 that is a readable / writable memory,
A magnetic disk 34 for storing control software and data, an input / output port 35 that is an interface with an accompanying input / output device, and a network port 36 that is 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 and 7. The desktop computer 30 is also provided with a display 38 and a keyboard 39 via the input / output port 35, and the operator confirms the display on the display 38 while checking the keyboard 39.
You can enter commands and parameters from.

The command input to the desktop computer 30 is processed based on the processing software, and is transmitted from the desktop computer 30 to the master controller 40, the tank controller 50 and the like via the network port 36 as needed. To be done. The master controller 40 controls the operation of the substrate transport robot TR (see FIG. 1). Further, the tank controller 50 is the tank controller 5
1 is transmitted to control the pouring / discharging liquid to each processing tank and the operation of the timer 52. The control of the pouring and draining liquid into the tank and the management of the timer 52 by the tank controller 50 will be described later in detail.

C. Structure of chemical bath: Next, substrate processing apparatus 1
The configuration of the chemical liquid tank CB1 provided in No. 00 will be described. Although the following description is for the chemical liquid tank CB1, the same applies to the chemical liquid tank CB2.

FIG. 3 is a chemical bath CB of the substrate processing apparatus 100.
It is a conceptual diagram explaining the structure of 1. The chemical liquid tank CB1 is composed of an inner tank 60, an outer tank 65, a vat 68, and a pouring / discharging mechanism associated with them.

The inner tank 60 is a tank for storing HF which is a chemical solution in the example shown here and for performing an etching process with HF on the immersed substrate W. The outer tank 65 is a tank for collecting the HF overflowing from the inner tank 60. The HF overflowing to the outer tank 65 is circulated to the inner tank 60 by the circulation pump 70, and the circulation filter 7
Purified by 1.

Pure water can be supplied to the inner tank 60 from pure water supply means 61. Pure water is supplied to the inner tank 60
It is performed by supplying from a nozzle (not shown) arranged inside, but it is not limited to this, and a known means such as providing a shower above the inner tank 60 can be applied. . Further, HF can be supplied to the inner tank 60 from the HF supply means 62.

The vat 68 is for collecting the HF that further overflows from the inner tank 60 and the outer tank 65.

The inner tank 60, the outer tank 65 and the bat 6 described above
The HF stored in 8 can be drained by the drain air valves (chemical liquid draining means) 73, 72, 74, respectively. The pure water supply means 61, H shown in FIG.
F supply means 62, circulation pump 70 and air valve 72,
The operations of all the tanks 73 and 74 are controlled by the tank controller 50 (see FIG. 2) via the tank controller 51.

When the treatment is carried out in the chemical bath CB1 shown in FIG. 3, first, HF is supplied from the HF supply means 62, and a predetermined amount of liquid necessary for the dipping treatment is stored in the inner bath 60 and the outer bath 65. After the supply of HF is stopped, the lot is immersed in HF in the inner tank 60, and the etching process on the substrate W is started. During the immersion process on the substrate W, the air valves 72, 73, 74 are
It is closed and the HF is circulated by the circulation pump 70. That is, in the steady state of immersion treatment,
Of the processing HF in the inner tank 60, the overflowing HF is the outer tank 6
After being collected in No. 5 and passed through the circulation pump 70 and purified by the circulation filter 71, the operation of supplying the inner tank 60 again is repeated.

D. Pure water replacement process in chemical bath: When trouble occurs in the substrate processing apparatus 100 (for example, failure of the substrate transport robot TR) during the etching process as described above, it is a feature of the substrate processing apparatus according to the present invention. Pure water replacement processing is performed in the chemical liquid tank. Less than,
The pure water replacement process in the chemical bath CB1 will be described.

FIG. 4 is a flow chart for explaining the procedure of the pure water replacement process in the chemical liquid tank CB1. First, after a predetermined amount of liquid necessary for the dipping process is stored in the inner tank 60 and the outer tank 65, it is determined whether or not a lot has been put into the chemical liquid tank CB1 (step S1). This decision is
This is performed by the tank controller 50 receiving from the master controller 40 a signal indicating that the substrate transfer robot TR has loaded the lot into the inner tank 60 of the chemical solution tank CB1. Note that this determination may be made by another method,
For example, a substrate sensor may be provided in the inner tank 60 and the substrate sensor may determine whether or not a lot has been loaded.

When it is determined that the lot has been put into the chemical bath CB1, the process proceeds to step S2, the timer 52 is started, and the soaked lot is soaked (step S3). Then, next, in step S4, it is determined whether or not the lot has been carried out from the chemical liquid tank CB1. Here, when it is determined that the lot has been carried out from the chemical liquid tank CB1, the process proceeds to step S8, the timer 52 is reset, and the process ends. On the other hand, when it is determined that the lot has not been carried out from the chemical liquid tank CB1, the process proceeds to step S5, and the time measured by the timer 52 is equal to or more than the sum of the “setting processing time” and the “setting allowable overtime”. It is determined whether or not. The tank controller 50 also makes the determinations in steps S4 and S5.

The processing time in each processing tank is set in advance in consideration of the type of the substrate to be processed and the convenience of the process. In the chemical solution tank CB1, the processing time required for the dipping processing is also set in advance. That is, when the “set processing time” has elapsed, the lot is normally unloaded. Therefore, the substrate processing apparatus 100
Is operating smoothly, the process from step S3 to step S5 is repeated, and when the “setting processing time” has passed, the lot is unloaded from the chemical liquid tank CB1 and the determination is made also in step S4. Then, the process proceeds to step S8, the timer 52 is reset, and the process ends.

However, if some trouble occurs in the substrate processing apparatus 100, the lot may not be carried out of the chemical bath CB1 even after the "set processing time" has elapsed. In such a case, it is determined in step S4 that the lot has not been carried out from the chemical liquid tank CB1, and thus the process proceeds to step S5. Here, the “set allowable overtime” is the allowable value for a lot in which the immersion treatment is still continued after the “setting treatment time” has elapsed from the time when the immersion treatment in the chemical liquid tank CB1 was started. The obtained excess time is a value that the operator inputs and sets as a parameter in advance. If the "set allowable overtime" is set to be extremely short, the deionized water replacement process described below will be executed even if the device has a minor trouble, for example, a slight deviation in the transport timing, and the like. If it is set long, the substrate W may be excessively etched and lot out before the pure water replacement process is performed. Therefore, it is necessary for the operator to set an appropriate value.

When it is determined in step S5 that the time measured by the timer 52 is equal to or more than the sum of the "set processing time" and the "set allowable overtime", that is, some trouble occurs in the substrate processing apparatus 100, If the trouble is not eliminated within the “set allowable overtime” and the lot is not carried out from the chemical liquid tank CB1, the pure water replacement process is executed. In this example, first, step S6
Then, the HF drainage is performed. HF drainage is air valve 7
This is done by opening 2, 73. And
After HF is drained from the inner tank 60 and the outer tank 65, the air valves 72 and 73 are closed, and then the process proceeds to step S7, where pure water is supplied from the pure water supply means 61 to the inner tank 60. .

In this way, the time lot that is equal to or more than the sum of the "set processing time" and the "set allowable overtime" is H.
When immersed in F, the inside of the inner tank 60 is replaced with pure water, so that the substrate W is not excessively etched, and as a result, the lot is prevented from being lot-out. it can.

If the inner tank 60 and the outer tank 65 are filled with pure water and then the pure water is circulated by the circulation pump 70, the HF adhering to the substrate W can be efficiently cleaned. , Higher effect can be achieved.

[0029]

[Modification] The embodiment of the present invention has been described above, but the present invention is not limited to the above example. For example, in the pure water replacement process, the HF drainage (step S6) is performed once. After that, pure water was supplied (step S7), but this may be performed only in step S7, that is, only pure water is supplied without performing HF drainage. In this case, H around the substrate W
The concentration of F gradually decreases and is eventually replaced with pure water. Therefore, although the time required for deionized water replacement increases, since the substrate W is not exposed to the air at all,
This is effective when it is not desired to naturally oxidize the surface of the substrate W. By supplying pure water only, the inner tank 60
The HF overflowing from the outer tank 65 may be collected by the vat 68, the air valve 74 may be opened, and the HF may be drained.

Further, in the above substrate processing apparatus 100, HF is used as the chemical solution, but the chemical solution is not limited to this, and a chemical solution sensitive to the processing time (for example, NH ₄ OH).
/ H ₂ O ₂ / H ₂ O mixed solution) may be used.

[0031]

As described above, according to the first aspect of the present invention, the chemical liquid tank is set on the basis of the time measured by the timer .
The immersion treatment time is calculated as the treatment time required for the immersion treatment.
When the preset processing time is reached,
The bot removes the substrate from the chemical bath and
Immersion treatment in the liquid tank is the set treatment time and the immersion treatment
Pre-set allowable over time that can be allowed to continue
And if it turns out that it was done for more than
Since the pure water supply from the water supply means is started , even if the substrate cannot be transported due to equipment trouble,
The chemical liquid in the chemical liquid tank will be replaced with pure water, and the substrate being processed will not be excessively etched. As a result, the substrate being processed becomes a defective product (lot out in the case of a lot). Can be prevented. Further, since the substrate is not exposed to the air at all, the substrate surface is not naturally oxidized.

Further, according to the second aspect of the invention, based on the time counting by the timer, the immersion treatment in the chemical solution tank can be permitted to continue the immersion treatment and the preset treatment time set as the treatment time required for the immersion treatment. If it is found that the time is equal to or more than the sum of the preset allowable overtime, the pure water is started to be supplied from the pure water supply means after the chemical liquid is once discharged from the chemical liquid tank. Even when the substrate cannot be transported due to a trouble of the apparatus, the chemical in the chemical bath is quickly replaced with pure water, and the substrate being processed is not excessively etched. As a result, the substrate being processed can be prevented from becoming a defective product (lot out in the case of a lot).

[Brief description of 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 liquid tank of the substrate processing apparatus of FIG.

FIG. 4 is a flowchart for explaining a procedure of pure water replacement processing in a chemical bath of the substrate processing apparatus of FIG.

[Explanation of symbols]

50 tank controller 52 timer 60 inner tank 61 Pure water supply means 65 outer tank 72, 73, 74 Air valve 100 substrate processing equipment CB1, CB2 chemical solution tank

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01L 21/304 B08B 3/08

Claims (2)

(57) [Claims] 1. A substrate processing apparatus for performing a dipping process on a substrate using a plurality of processing baths , comprising: (a) storing a chemical solution, and dipping the substrate in the chemical solution. (B) Pure water is stored in the chemical bath and the substrate is cleaned with the pure water.
A washing tank for performing, (c) pure water supply means for supplying pure water to the chemical solution tank, and (d) carrying the substrate between the chemical solution tank and the washing tank
A substrate transfer robot, and (e) comprising a timer capable of measuring the passage of time from the time when the immersion treatment in the chemical solution tank is started, based on the time measured by the timer, the immersion treatment time in the chemical solution tank Is required for immersion treatment
When it reaches the preset processing time as a processing time
Is the substrate from the chemical bath by the substrate transfer robot.
And carry out the immersion treatment in the chemical solution tank for the set treatment time and
Allowable to continue pickling process.
-When it is found that the time is more than the sum of the time and
The substrate processing apparatus is characterized by starting the pure water supply from the pure water supply means . 2. The substrate processing apparatus according to claim 1, further comprising: (f) a chemical liquid draining means for draining the chemical liquid from the chemical liquid tank, wherein the immersion in the chemical liquid tank is based on a time measured by the timer. If it is found that the treatment is performed for a time longer than the sum of the preset treatment time required as the treatment time required for the immersion treatment and the preset allowable tolerance time over which the continuation of the immersion treatment can be permitted, once, The substrate processing apparatus is characterized in that after the chemical liquid is drained from the chemical liquid tank, the pure water supply from the pure water supply means is started.