JPH0810673A - Substrate treatment device - Google Patents

Abstract

PURPOSE:To allow a dilution-adjusted concentration to correspond to a substrate immersion time and thereby maintain a treatment quality at a specific level by determining the substrate immersion time in accordance with a change in the dilution- adjusted concentration of a substrate treatment liquid, and suspending the immersion of a substrate using the substrate treatment liquid whose dilution adjustment is finished, if the substrate immersion time elapsed. CONSTITUTION:A substrate treatment device 10 etches a substrate W stored in a treatment tank 12 by immersing the substrate in an aqueous HF solution obtained by diluting it by pure water. On the other hand, an electronic control device 40 enters each detection signal from each flow sensor 24, 32 in each pure water and HF feed tubular path 20, 28, the treatment tank 12, a temperature sensor 17, an HF concentration sensor 15 for an overflow tank 14, and an HF passage sensor 33, in the substrate treatment device 10. In addition, the electronic control device 40 controls each flow control valve 22, 30, 38. In this case, the device 40 determines a substrate immersion time in accordance with a change in a dilution-adjusted concentration of a substrate treatment liquid, and at the same time the immersion of the substrate using the substrate treatment liquid is suspended, if the substrate immersion time elapsed after the commencement of displacing the substrate treatment liquid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate processing apparatus for processing various substrates such as semiconductor wafers and glass substrates for liquid crystal panels by immersing them in a diluting solution of a substrate processing liquid for substrate cleaning and etching in a processing tank. Regarding

[0002]

2. Description of the Related Art Conventionally, in a substrate processing apparatus of this type, for example, a substrate processing apparatus which subjects a substrate to etching treatment with hydrofluoric acid (hereinafter referred to as HF), the substrate is stored in a processing tank.
Pure water and an HF aqueous solution are supplied to this processing tank to prepare a diluted solution of the HF aqueous solution, and the substrate is treated, that is, etching is performed by immersing the substrate in the diluted HF aqueous solution for a predetermined time. Further, in the substrate processing apparatus for cleaning the substrate, instead of the HF aqueous solution, a chemical solution (substrate processing solution) such as hydrogen peroxide solution or ammonia water is supplied to the processing tank, and the substrate cleaning is performed by diluting these chemical solutions. To do.

It is well known that in such a substrate processing apparatus, the quality of the substrate processing depends on the diluted preparation concentration of the substrate processing liquid in the processing bath. Therefore, various techniques have been proposed for supplying pure water or a substrate processing liquid. For example, in Japanese Utility Model Laid-Open No. 4-99269, a substrate processing liquid is mixed with pure water in a pure water supply pipe to prepare a diluted solution, and the amount of the substrate processing solution after the diluted preparation is measured to measure the substrate processing solution. A technique has been proposed in which the supply amount of the substrate processing liquid is adjusted so that the measured supply amount becomes a preset supply amount. In addition, in Kaikaihei 5-53241, the substrate treatment liquid is mixed with pure water in a pure water supply pipe to make a dilution, and the concentration of the substrate treatment liquid after the dilution is detected and the detected concentration is preset. Techniques have been proposed for adjusting the supply amount of the substrate processing liquid so that the concentration becomes the specified concentration. Then, these conventional techniques maintain the quality of the substrate processing by adjusting the supply amount of the substrate processing liquid to a predetermined diluted concentration of the substrate processing liquid.

[0004]

However, even in the above-described conventional substrate processing apparatus, the substrate processing quality is sometimes deteriorated. It can be considered as follows that the substrate processing quality deteriorates despite the adjustment of the supply amount of the substrate processing liquid as described above.

Since the substrate processing liquid is diluted with pure water, if the supply amount or supply pressure of the pure water changes, the flow rate ratio to the pure water changes even if the supply amount of the substrate processing liquid is uniform. The dilution concentration will change. This fluctuation related to the supply of pure water depends on the supply capacity of the pure water supply device, which is the primary side of the substrate processing apparatus, and the operating conditions of other devices that use pure water, and therefore may inevitably occur. is there. In addition,
Even if a flow rate control valve or the like is installed in the pure water supply pipe to control the flow rate, it is not possible to eliminate the pressure fluctuation of the pure water supply pressure, and this is not an essential solution.

That is, as in the prior art described above, it is sufficient to dilute the substrate processing liquid by adjusting the supply amount of the substrate processing liquid and immerse the substrate in the diluted substrate processing liquid for a predetermined time. Due to the change in the dilution concentration of the substrate processing liquid due to the water supply side, the etching amount and the degree of foreign matter removal by the cleaning chemical liquid may become non-uniform, resulting in deterioration of substrate processing quality.

Even if there is no fluctuation in the supply amount or pressure on the pure water supply side, if the concentration of the original substrate processing liquid to be mixed with pure water changes, the substrate processing will be described more specifically. Whenever the concentration of the liquid storage container is changed or each time a new substrate processing liquid is replenished to the container,
Even if the supply amount of the substrate processing liquid is uniform, the dilution concentration after mixing with pure water changes. Therefore, even in such a case, the substrate processing quality may be deteriorated, so that strict concentration control is required every time such as the substrate processing liquid itself and replenishment, and the handling of the substrate processing liquid is complicated. Further, when the voltage applied to the pump for pumping the substrate processing liquid in the pipeline fluctuates, the flow rate of the pump may fluctuate and the dilution concentration may also change.

The present invention has been made to solve the above problems, and an object of the present invention is to simplify the handling of a substrate processing solution and to maintain the processing quality when processing a substrate with a dilute solution of the substrate processing solution. To do.

[0009]

In order to achieve the above object, the means adopted by the substrate processing apparatus according to claim 1 is a means for accommodating a substrate, receiving pure water and a substrate processing liquid, and receiving the substrate processing liquid. A treatment tank for immersing and treating the substrate in the diluted solution, pure water supply means for supplying pure water to the treatment tank, and substrate treatment liquid supply means for supplying a substrate treatment liquid to the treatment tank. The substrate processing liquid supply means and the pure water supply means are controlled to supply and stop the supply of the pure water and the substrate processing liquid to the processing tank, and after the processing tank is filled with pure water, A substrate processing apparatus comprising: control means for substituting pure water in the processing tank with the substrate processing solution so that the solution in the tank overflows from the processing tank, and diluting the substrate processing solution. Was supplied by the substrate processing liquid supply means. A timekeeping unit that measures the elapsed time from the start of the replacement of pure water in the processing bath with the plate processing liquid, the concentration of the substrate processing liquid, and the substrate immersion time of the substrate in the processing bath are stored in association with each other. A storage unit, a substrate processing liquid concentration detection unit that detects the concentration of the substrate processing liquid, and a substrate processing liquid concentration at the time of preparation of dilution of the substrate processing liquid detected by the substrate processing liquid concentration detection unit and the storage unit Depending on the storage result, when the immersion time determination unit for determining the substrate immersion time by the diluted substrate processing liquid, and the time counting unit measures the elapsed substrate immersion time, the diluted prepared substrate The gist of the invention is to include a substrate immersion stopping unit that stops the immersion of the substrate in the processing liquid.

In this case, in the substrate processing apparatus according to the second aspect, when the substrate immersion stopping unit measures the elapsed time of the determined substrate immersion time by the timer unit, the pure water supply means is controlled to perform the process. The diluted substrate processing solution in the tank was replaced with pure water.

According to another aspect of the substrate processing apparatus of the present invention, the pure water supply means and the substrate processing liquid supply means supply pure water or a substrate processing liquid to the processing bath from the bottom thereof.
The substrate processing liquid concentration detection unit detects the substrate processing liquid concentration in the bath liquid overflowing from the processing bath.

According to another aspect of the substrate processing apparatus of the present invention, there is provided a temperature detecting unit for detecting the temperature of the bath liquid in the processing bath, and a dipping process for correcting the determined substrate dipping time according to the detected bath liquid temperature. And a time correction unit.

[0013]

In the substrate processing apparatus having the above structure, the substrate processing liquid concentration and the storage unit detected by the substrate processing liquid concentration detection unit during the dilution preparation of the substrate processing liquid by the immersion time determination unit of the control means. The substrate immersion time with the diluted substrate treatment liquid is determined according to the storage result of the above. Therefore, for some reason, for example, even if the supply amount or supply pressure of pure water is changed or the concentration of the substrate processing liquid before being diluted with pure water is changed, the diluted preparation concentration of the substrate processing liquid is changed. , The substrate immersion time is determined according to the changed dilution concentration.

On the other hand, the timer unit measures the elapsed time after the replacement of the pure water in the processing tank with the substrate processing liquid supplied by the substrate processing liquid supply means is started, and the replacement of the pure water is performed. When the time counting section determines that the board immersion time determined by the immersion time determining section has elapsed from the start,
The substrate immersion in the diluted substrate processing solution is stopped by the substrate immersion stopping unit. Therefore, the substrate is subjected to the immersion treatment with the substrate treatment liquid having the diluted preparation concentration for the substrate immersion time determined according to the dilution concentration of the substrate treatment liquid, and thereafter, the treatment with the substrate treatment liquid having the diluted preparation concentration. Is not attached to.

In the substrate processing apparatus according to the second aspect of the present invention, the suspension of the substrate in the diluted and prepared substrate processing liquid is stopped so that the diluted and prepared substrate processing liquid in the processing tank is controlled by the pure water supply means. Replace with water. Therefore, after the immersion treatment with the substrate treatment liquid having the diluted preparation concentration for the substrate immersion time determined according to the dilution concentration of the substrate treatment liquid, the substrate is subjected to deionized water replacement and then the substrate treatment liquid is processed in the treatment tank. To be washed.

In the substrate processing apparatus according to the third aspect, the pure water and the substrate processing solution are supplied to the processing tank from the bottom of the processing tank, and the concentration of the substrate processing solution is detected by the solution in the tank overflowing from the processing tank. To do. Since the pure water and the substrate processing solution are supplied from the bottom of the processing tank, the overflowing solution in the tank is sufficiently mixed with the substrate processing solution and the pure water, so that the substrate processing solution is uniformly diluted. It becomes a solution and accurately reflects the diluted concentration of the substrate processing liquid. Therefore, through the accurate detection of the diluted concentration, the substrate immersion time is determined by accurately corresponding the diluted concentration of the substrate processing liquid and the substrate immersion time.

In the substrate processing apparatus according to the fourth aspect, the substrate immersion time is corrected by the immersion time correction unit in accordance with the bath liquid temperature in the processing bath detected by the temperature detection unit. Suppress fluctuations in substrate processing quality.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, preferred embodiments of the substrate processing apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram schematically showing a configuration of a substrate processing apparatus 10 for immersing a substrate in a dilute HF aqueous solution and etching the substrate.

As shown in the drawing, the substrate processing apparatus 10 comprises a processing bath 12 made of quartz glass, and a substrate W stored inside the processing bath 12 using a carrier (not shown),
Etching is performed by immersing in a dilute HF aqueous solution diluted with pure water. An overflow tank 14 into which the liquid in the tank overflowing the tank flows into the opening of the processing tank 12.
Are provided so as to surround the opening. Also,
A pair of left and right nozzles 16 for ejecting pure water (DIW) or a diluted HF aqueous solution into the tank is installed in the processing tank 12 at the bottom of the processing tank, and the temperature of the liquid in the tank is detected on the side wall of the processing tank. A temperature sensor 17 is installed. On the other hand, the overflow tank 14 is provided with an HF concentration detection sensor 15 for detecting the HF aqueous solution concentration in the tank liquid that has overflowed to the layer. The HF concentration detection sensor 15
For example, a charge-type sensor, a light-transmitting sensor, or the like can be used.

The nozzle 16 has a nozzle opening position and a nozzle shape that do not generate irregular convection in the tank when jetting pure water or the like, and is made of quartz glass like the processing tank 12. Further, the in-tank liquid that has flowed into the overflow tank 14 is discharged through the drain conduit 19.

A pure water supply pipe line 20 for supplying pure water from a pure water supply device 18 is branched to each nozzle 16 of the processing tank 12. In this pure water supply line 20,
A flow rate control valve 22 for controlling the flow rate of pure water flowing through the pipeline.
And a flow rate detection sensor 24 for detecting the flow rate. The flow rate control valve 22 is used for the pure water supply line 2
It is also possible to cut off 0 and set the pure water flow rate to 0.

Further, an HF supply pipe 28 for supplying the HF aqueous solution from the sealed HF aqueous solution storage tank 26 is branched and provided in the pure water supply pipe 20 near the processing tank 12. . In the HF supply pipeline 28, a flow rate control valve 30 that controls the flow rate of the HF aqueous solution flowing through the pipeline.
And a flow rate detection sensor 32 for detecting the flow rate. The flow control valve 30 is also the flow control valve 22.
As in the above, the flow path can be made zero by shutting off the pipeline.

In addition, the pure water supply pipe 20 is provided with an HF passage detection sensor 33 for detecting that the HF aqueous solution has passed through the pipe at the point before reaching the processing tank 12. The HF passage detection sensor 33 detects the passage of the HF aqueous solution and detects the passage of the HF aqueous solution.
It is used to determine when the replacement has started. In this case, the HF passage detection sensor 33 can detect passage of the HF aqueous solution in the pipeline by detecting whether the fluid passing through the pipeline is pure water or pure water mixed with the HF aqueous solution. Therefore, as the HF passage detection sensor 33, a ph sensor or the like can be used in addition to an HF aqueous solution concentration detection sensor such as a charge type sensor or a light transmission type sensor.

A nitrogen gas supply device 34 for supplying pressurized nitrogen gas into the tank under pressure is connected to the HF aqueous solution storage tank 26 via a nitrogen gas supply pipeline 36. The nitrogen gas supply pipeline 36 is provided with a flow rate control valve 38 for controlling the flow rate of nitrogen gas flowing through the pipeline. Like the flow control valve 22, the flow control valve 38 can also shut off the pipe to set the flow rate to zero.

Therefore, the pure water supply pipe 20 is opened by the flow control valve 22 while the HF supply pipe 28 is blocked by the flow control valve 30, so that the nozzle 16 at the bottom of the processing tank 12 is opened.
It is possible to supply only pure water to the processing tank 12 from above and to fill the processing tank 12 with pure water. Further, when the HF supply pipe 28 is opened by the flow rate control valve 30 while flowing pure water into the pure water supply pipe 20, pure water and HF aqueous solution are mixed in the treatment tank 12 upstream thereof and diluted with pure water. The diluted diluted HF aqueous solution is supplied. Then, by continuing to supply the diluted HF aqueous solution,
The pure water filled in the processing tank 12 is gradually replaced with the diluted HF aqueous solution and overflows into the overflow tank 14, and the inside of the processing tank 12 is eventually filled with the diluted HF aqueous solution.

When the diluted HF aqueous solution is further supplied, the diluted HF aqueous solution overflows into the overflow tank 14. In this case, since the pure water and the HF aqueous solution in the mixed state are supplied from the bottom of the processing tank 12, the processing tank 1
Also in 2, the mixing of the pure water and the HF aqueous solution progresses so that the diluted concentration of the HF aqueous solution becomes uniform, and thus the diluted HF aqueous solution having a uniform diluted concentration overflows into the overflow tank 14. It should be noted that the uniform dilution concentration here does not mean that the dilution concentration becomes uniform with respect to the set dilution concentration, but is determined each time by the pure water and the HF aqueous solution mixed and supplied to the processing tank 12. Means dilution concentration.

The above-mentioned supply of the HF aqueous solution is carried out by increasing the internal pressure of the tank by the pressurized supply of the nitrogen gas from the nitrogen gas supply device 34 to the HF aqueous solution storage tank 26 via the nitrogen gas supply pipeline 36. At this time, the flow control valve 38
The flow rate is adjusted at.

Next, the electronic control unit 40 that controls the supply of pure water or HF aqueous solution in the substrate processing apparatus 10 will be described.

The electronic control unit 40 has, as a signal input device, a flow rate detecting sensor 24 and a flow rate detecting sensor 3 for detecting the flow rates in the pure water supply pipeline 20 and the HF supply pipeline 28.
2, the temperature sensor 17 in the processing tank 12, the HF concentration detection sensor 15 in the overflow tank 14, and the HF passage detection sensor 33 in the pure water supply pipe 20 are connected, and the detection signals of the above sensors are electronically controlled. Device 40
Is input to Further, the flow rate control valve 22, the flow rate control valve 30, and the flow rate control valve 38 are connected as control signal output devices, and a control signal is output from the electronic control unit 40 to each control valve.

The electronic control unit 40 which outputs a control signal to the above-mentioned flow control valve 22 or the like based on these detection signals or the like,
The CPU 42, the ROM 44, the RAM 46, and the timer 48 are mainly configured as a logical operation circuit, and input / output with the outside is performed by an input / output port 52 mutually connected through a common bus 50.

Next, the substrate immersion processing control (routine) performed by the electronic control unit 40 of the substrate processing apparatus 10 of the present embodiment having the above-mentioned configuration will be described with reference to the flowchart of FIG.

In the substrate dipping processing routine shown in FIG. 2, the substrate W is put into a predetermined position of the processing tank 12 by a substrate transfer device (not shown) and the storage is completed, and the electronic control unit 40 sends a storage completion signal from the substrate transfer device. It is executed when you receive it.
Then, when the processing is started, first, the supply of pure water to the processing tank 12 is started (step S100). At this time, the electronic control unit 40 outputs a control signal that determines the control flow rate to the flow rate control valve 22 in the pure water supply pipe line 20, so that the flow rate of pure water is controlled by the flow rate control valve 22 and processed. It is supplied to the tank 12 alone.

Subsequently, whether or not the processing tank 12 is filled with pure water, that is, pure water flows from the processing tank 12 to the overflow tank 14
It is determined whether or not the overflow has occurred (step S10
5) Wait until an affirmative decision is made. This step S10
Since the supply of pure water is continued even while waiting for a negative judgment in 5 and waiting, the processing tank 12 is eventually filled with pure water and the pure water overflows into the overflow tank 14, and an affirmative judgment is made in step S105. Will be done. Specifically, the overflow of pure water is determined as follows.

Since the inner volume of the processing tank 12 is determined at the design stage of the substrate processing apparatus 10, pure water is treated by the processing tank 12 by using the flow rate detected by the flow rate detection sensor 24 or the control flow rate commanded by the electronic control unit 40. It is possible to calculate the time (pure water overflow time) required for the water to be supplied to the overflow tank 14 until it overflows into the overflow tank 14. Therefore, if this pure water overflow time elapses after the pure water supply is started in step S100, it can be said that the pure water overflow has occurred, and the determination in step S105 becomes affirmative. It should be noted that the presence or absence of overflow of pure water may be determined from the condition of fluid passage through the drain conduit 19.

After the affirmative determination is made in step S105, H
In order to prepare the diluted HF aqueous solution by supplying the F aqueous solution to the treatment tank 12 filled with pure water and diluting it, the supply of the HF aqueous solution to the treatment tank 12 is started (step S110). On this occasion,
From the electronic control unit 40, a control signal that determines the respective control flow rates is output to the flow rate control valve 38 in the nitrogen gas supply pipeline 36 and the flow rate control valve 30 in the HF supply pipeline 28. Therefore, the flow rate of the HF aqueous solution is controlled by these flow rate control valves, and is mixed into the pure water supply pipe line 20,
It is supplied together with pure water to the processing tank 12 through the pure water supply pipe 20 in the downstream area. Therefore, the HF aqueous solution is diluted with pure water in the pure water supply pipe line 20 while being treated.
Will be supplied to. In the following description of each step, each process will be described with appropriate reference to the timing chart shown in FIG.

At step S110, the time t shown in FIG.
When the supply of the HF aqueous solution is started in 1, in the subsequent step S115, it is determined whether or not the HF aqueous solution is actually supplied to the processing tank 12 based on the detection signal of the HF passage detection sensor 33, and waits until a positive determination is made. To do. This treatment is for confirming whether the HF aqueous solution is actually supplied to the treatment tank 12. Therefore, as shown in FIG. 1, the case where the HF aqueous solution reaches the processing tank 12 immediately after the supply of the HF aqueous solution is started in step S110,
In the case of a configuration (not shown) in which the supply pipeline 28 is directly piped to the nozzle 16, step S115 can be omitted. In the following description, unless otherwise specified, the HF aqueous solution reaches the processing tank 12 immediately after the supply of the HF aqueous solution is started.

In step S115, HF is added to the processing tank 12.
If a positive judgment is made that the aqueous solution was actually supplied, the processing tank 1
The dilution of the HF aqueous solution with the stored pure water and the replacement of the diluted HF aqueous solution with the stored pure water in 2 are started. Therefore, as shown in FIG. 3, if an affirmative decision is made in step S115 at time t1, the HF will be transferred to the processing tank 12.
The elapsed time (mixing supply time) Ts from the time when the aqueous solution is actually supplied together with the pure water is measured by the timer 48 at time t1.
(Step S120). After that, whether or not the processing tank 12 is filled with the diluted HF aqueous solution diluted with pure water, that is, all the stored pure water overflows from the processing tank 12 to the overflow tank 14, and the diluted HF is further diluted.
It is determined whether or not the aqueous solution has overflowed into the overflow tank 14 (step S125), and the process waits until a positive determination is made.

By the way, the HF supply line 28 is connected to the processing tank 12.
Since it is connected to the pure water supply line 20 apart from
Even if the supply of the F aqueous solution is started, if it does not reach the processing tank 12 immediately after the start of the supply, the process is as follows. That is, the time Δt from the start of the supply of the HF aqueous solution to the arrival of the HF aqueous solution in the processing tank 12 in step S110.
Is determined by the flow rate of pure water or HF aqueous solution, the flow velocity in the pipe, the pipe length from the connection point of the HF supply pipe 28 to the processing tank 12, and the like. Therefore, if the HF aqueous solution does not reach the processing tank 12 immediately after the start of the supply, step S125.
In step S11, before the time t1 at which the timer 48 starts measuring the elapsed time Ts,
It is sufficient to perform 0. At this time, since the time t1 is specified in step S115 after the supply of the HF aqueous solution is started in step S100, it is not necessary to calculate the time Δt.

The supply of pure water and the HF aqueous solution is continued even while waiting for a negative determination in step S125. For this reason, all of the stored pure water is eventually replaced with the diluted HF aqueous solution, the treatment tank 12 is filled with this diluted HF aqueous solution, and the diluted HF aqueous solution is overflowed.
, And an affirmative decision is made in step S125. In this case, overflow of the diluted HF aqueous solution is determined as in step S105.

That is, first, the HF aqueous solution is used by using the internal volume of the processing tank 12 and the flow rates of the pure water and the HF aqueous solution detected by the flow rate detecting sensor 24 and the flow rate detecting sensor 32 or the control flow rate instructed from the electronic control unit 40. Calculate the overflow time. The time when the calculated HF aqueous solution overflow time elapses from the time t1 when the HF aqueous solution is actually supplied to the processing tank 12 is defined as the time t2 when the diluted HF aqueous solution overflows. In this embodiment, the time t3 which is a predetermined time after the time t2 has elapsed.
In step S125, a positive determination is made.

Further, the determination in step S125 can be configured as follows. Since the supply of the HF aqueous solution to the processing tank 12 is started under the condition that the processing tank 12 is already filled with pure water, as shown in FIG. 3, the passage of time from the start of the supply (time t1). At the same time, the stored pure water is replaced with the HF aqueous solution. For this reason,
The diluted concentration of the HF aqueous solution in the treatment tank 12 rises with the passage of time and becomes stable over time. That is, the dilution concentration of the HF aqueous solution in the treatment tank 12 is the actual concentration of the pure water and the HF aqueous solution mixed and supplied to the treatment tank 12 when the treatment tank 12 is filled with the diluted HF aqueous solution and the diluted HF aqueous solution overflows. Dilution ratio (H
It stabilizes at F1). Therefore, when the HF concentration detection sensor 15 provided in the overflow tank 14 is scanned at predetermined time intervals by a measurement routine (not shown) and the difference in the detected concentration at each scan changes to a very small value, the diluted HF aqueous solution overflows from the measurement routine. It is configured to output a control signal to the effect. Then, when the control signal is received (time t3), an affirmative decision is made in step S125.

Following the affirmative judgment in step S125, a control signal of a flow rate of 0 is output to the flow rate control valve 22, the flow rate control valve 30 and the flow rate control valve 38, and pure water and an HF aqueous solution are supplied to the processing tank 12. Supply is stopped (step S13)
0). Therefore, after that, the processing tank 12 remains in a state of being filled with the diluted HF aqueous solution in which the diluted concentration becomes uniform with the above-mentioned diluted concentration HF1, and the substrate W is immersed in the diluted HF aqueous solution having the diluted concentration HF1. Is etched.

Next, the dilution concentration HF1 is read from the HF concentration detection sensor 15 (step S140), and the temperature of the diluted HF aqueous solution in the processing bath 12 (fluid temperature in the bath).
Reading from the temperature sensor 17 (step S150)
And execute After that, the substrate immersion time THF for immersing the substrate W in the read diluted concentration HF1 is calculated as follows (step S160).

First, the diluted concentration HF1 read, and FIG.
The substrate immersion time is once calculated through interpolation calculation from the map corresponding to the graph of HF aqueous solution concentration and substrate immersion time THF shown in FIG. This graph is obtained by experimentally determining the HF aqueous solution concentration and the immersion time when the same substrate etching amount is obtained, and the map corresponding to the graph is ROM.
It is stored in 44. Next, the value obtained by correcting the calculated substrate processing time by the liquid temperature in the bath that has been read is used as the substrate immersion time THF1 for actually immersing the substrate W in the read dilution concentration HF1. Therefore, the flow ratio of pure water to the HF aqueous solution changes due to some cause, such as fluctuations in the pure water supply amount or supply pressure, and the newly read dilution concentration is lower than the previous dilution concentration HF1, as shown in FIG. Concentration HF2
If so, the substrate immersion time THF for actually immersing the substrate W in this diluted concentration HF2 is longer than THF1.
Calculated as HF2.

Even if the dilute HF aqueous solution has the same dilution concentration, if the liquid temperature is high, the etching by dipping progresses further.
Correct HF. That is, if the liquid temperature in the bath is higher than the reference liquid temperature, the substrate processing time is corrected to the decrease side, and if it is low, it is corrected to the increase side.

When the substrate immersion time THF is calculated through the temperature correction calculation in this way, the calculated substrate immersion time THF (T
HF1, THF2) determines whether or not it has elapsed since the start of supplying the HF aqueous solution to the processing tank 12 through the elapsed time Ts measured by the timer 48 (step S165). Then, the substrate immersion time THF (THF calculated by the elapsed time Ts)
1. Wait while denying that THF2) has not been reached.

Therefore, the substrate W is immersed in the diluted HF aqueous solution for etching during the waiting time when the determination is negative in step S165, and the substrate immersion time THF that affects the processing quality as the etching amount is the diluted HF. It is changed each time depending on the actual dilution concentration of the aqueous solution. Specifically, if the diluted concentration of the diluted HF aqueous solution is HF1, the substrate W is immersed for the substrate immersion time THF1, and if the diluted concentration is HF2, the substrate W is immersed for the substrate immersion time THF2. become.

On the other hand, if it is judged in step S165 that Ts = substrate immersion time THF (THF1, THF2), the elapsed time Ts is set to a value of 0 (step S170), and then the pure water which has been stopped until then is reached. Is started to be supplied (step S180). That is, if the diluted concentration of the diluted HF aqueous solution is HF1, after the time t4 (t1 + THF1) after the substrate immersion for the substrate immersion time THF1, and if the diluted concentration is HF2, the substrate immersion time THF2. After a lapse of time t5 (t1 + THF2), the immersion treatment of the substrate W at the dilution concentration (HF1, HF2) is stopped. After time t4 or time t5, the diluted HF aqueous solution in the processing tank 12 is replaced with pure water by the supply of pure water, and the processing tank 12 is filled with pure water. It is washed in.

When the supply of pure water is started in step S180, the flow rate is controlled as follows. When pure water is supplied to the processing tank 12, the inside of the processing tank 12 is diluted with H
Since the F aqueous solution is gradually replaced with pure water, the concentration of the HF aqueous solution from the start of the replacement (time t4 or time t5) changes as shown in FIG. FIG. 5 shows the state when the pure water is replaced together with the state when the inside of the processing tank 12 is replaced with the HF aqueous solution. The pure water replacement is shown only when the replacement is started at time t4.

As shown in FIG. 5, since the HF aqueous solution remains in the processing bath 12 even after the pure water replacement is started at the time t4, the substrate W remains in the processing bath 12 even after the pure water replacement is started. It is considered that the residual dilute HF aqueous solution remaining in No. 12 is used for etching. More specifically, the substrate W
Is the time t from the time t4 when the concentration of the HF aqueous solution becomes zero.
It is considered that the etching is performed in the residual diluted HF aqueous solution whose concentration is lower than the diluted concentration HF1 during the substrate immersion time and gradually decreases over the period up to 6. The etching amount (excessive etching amount) during this period is
Geometrically, the area S1 of the range shown by the diagonal lines in FIG.
Is equivalent to

On the other hand, when starting the substrate processing for supplying the HF aqueous solution to the processing bath 12, pure water remains in the processing bath 12 even after the replacement of the diluted HF aqueous solution is started at time t1. Therefore, during the period from time t1 to time t2 when the concentration of the HF aqueous solution becomes the dilution concentration HF1, the substrate W
Is the dilution concentration HF1 from zero concentration to substrate immersion time.
It is considered that the etching is performed with a dilute HF aqueous solution that gradually increases. Then, during this period, the etching shortage amount (the etching amount between the time t1 and the time t2 by the HF aqueous solution having the diluted concentration HF1 and the etching amount between the time t1 and the time t2 by the diluted HF aqueous solution whose concentration gradually increases to the diluted concentration HF1 The difference from the etching amount), when expressed geometrically, corresponds to the area S0 in the range indicated by the diagonal lines in FIG.

Therefore, in step S180, when the pure water is supplied so that the above-described excess etching amount and the above-described insufficient etching amount become equal, specifically, the area S1 and the area S0 in FIG. Control the pure water flow rate.

Subsequent to step S180 involving the control of the pure water flow rate as described above, it is judged whether or not the cleaning of the substrate W with pure water is completed through the elapse of a predetermined time from time t4 or time t5. (Step S185), and when the pure water cleaning is completed, the supply of pure water is stopped (step S19).
0). Next, the substrate W is treated in the treatment tank 1 assuming that the processing of the substrate W in the treatment tank 12 is completed by the completion of the pure water cleaning.
2 In order to take it out to the outside, a substrate carry-out command signal is output (step S200), and this routine is once ended. A substrate transfer device (not shown) receives the substrate unloading command signal and unloads the substrate W from the processing bath 12.

By the way, as described above, the HF supply line 2
In the case where 8 is separated from the treatment tank 12 and connected to the pure water supply pipeline 20, the pure water supply pipeline 20 from the connection point of the HF supply pipeline 28 to the treatment tank 12 is connected. The HF aqueous solution remains at the diluted concentration during the substrate immersion treatment. Therefore, in the case of such a configuration, step S
Even if the supply of pure water was started at 180, the pure water did not reach the processing tank 12 immediately and the HF aqueous solution in the pipe was also supplied at the beginning of the supply, and the pure water was supplied to the processing tank 12 only after a predetermined time Δt0. Not supplied. That is, the replacement of pure water in the processing tank starts after a lapse of a predetermined time Δt0 from the start of pure water supply in step S180. Therefore, the HF supply line 28 is the processing tank 1
In the case of a configuration in which it is connected to the pure water supply pipe line 20 apart from 2, the pure water supply in step S180 may be performed as follows. First, the above predetermined time Δt0
Is calculated from the flow rates of pure water and HF aqueous solution, the flow velocity in the pipe, the pipe length from the connection point of the HF supply pipe 28 to the processing tank 12, and the like. Then, before the time t4 or the time t5 at which the deionized water in the processing tank 12 starts to be replaced by a predetermined time Δt0, or after the time calculated by (substrate immersion time THF-Δt0) has elapsed from the time t1, S18
0 is performed, and pure water is supplied from time t4 or time t5 by Δt0
Just start early. This predetermined time Δt0
Calculation is completed within the substrate immersion time, so there is no problem.

As described above, the substrate processing apparatus 10 of the present embodiment uses pure water and H due to fluctuations in the pure water supply amount and supply pressure.
Even if the diluted concentration of the diluted HF aqueous solution in the processing tank 12 changes each time the substrate is processed, for example, the flow rate ratio of the F aqueous solution changes, or the HF aqueous solution concentration changes due to replacement of the HF aqueous solution storage tank 26. The substrate immersion time THF of the substrate W is changed and set accordingly. Furthermore, the substrate processing apparatus 1
0 means that after dipping the substrate W in the dilute HF aqueous solution having the dilute concentration each time in the treatment tank 12 for the substrate dipping time THF, the subsequent dipping of the substrate in the dilute HF aqueous solution having the dilute concentration is stopped. The substrate W is washed with pure water.

Therefore, since the etching amount, which is the processing quality of the substrate W, depends on the dilution concentration of the diluted HF aqueous solution and the immersion time, the substrate processing apparatus 10 of the present embodiment allows the dilution concentration of the diluted HF aqueous solution to be increased. It is possible to make the etching amount uniform and maintain its processing quality through the correspondence between the immersion time and the immersion time. Further, according to the substrate processing apparatus 10, even if the concentration of the HF aqueous solution changes due to the replacement of the HF aqueous solution storage tank 26, the etching amount and thus the processing quality can be maintained. The need for strict control is eliminated, and its handling can be simplified.

Further, in the substrate processing apparatus 10, since the substrate W is subjected to pure water cleaning after being immersed in the diluted HF aqueous solution, it can be taken out without attaching the diluted HF aqueous solution to the substrate W. Therefore, according to the substrate processing apparatus 10, careless etching after dipping the substrate can be avoided. Moreover, since it has been washed with pure water, it is convenient for the subsequent steps.

Further, the substrate processing apparatus 10 is provided with the processing tank 1
The pure water and the HF aqueous solution are mixedly supplied to 2 from the bottom of the tank by the nozzle 16. Therefore, the mixing of the pure water and the HF aqueous solution is promoted also in the processing tank 12, and the dilution concentration of the HF aqueous solution is set to a uniform dilution concentration determined by the pure water flow rate, the HF aqueous solution flow rate, etc. at that time, and this uniform dilution concentration is obtained. Diluted HF
The aqueous solution is overflowed into the overflow tank 14. Then, the dilution concentration thus homogenized is detected by the HF concentration detection sensor 15 in the tank liquid (diluted HF aqueous solution) overflowing from the processing tank 12. Therefore, according to the substrate processing apparatus 10, the accurate substrate immersion time can be set by detecting the accurate diluted concentration of the diluted HF aqueous solution in the processing tank 12, so that the etching amount can be made more uniform and the processing quality can be maintained. It is possible to improve.

Further, the substrate processing apparatus 10 increases or decreases the substrate immersion time of the substrate W according to the temperature of the diluted HF aqueous solution in the processing bath 12 to optimize the substrate immersion time. Therefore, according to the substrate processing apparatus 10, the fluctuation of the etching amount due to the temperature change of the diluted HF aqueous solution in the processing tank 12 can be suppressed, and the processing quality can be maintained or improved.

Further, in the substrate processing apparatus 10 of this embodiment,
It has the following advantages. Since the nozzle 16 of the processing tank 12 is made of quartz glass, the degree of diluting HF is small.
The nozzle opening of the nozzle 16 may be slightly corroded or etched by the aqueous solution. Therefore, according to the substrate processing apparatus 10, the substrate immersion time is determined according to the actual dilution concentration of the diluted HF aqueous solution.
The etching amount of the nozzle opening 6 can be made uniform every time the substrate is processed. Therefore, even in such a case, the pure water or the HF aqueous solution can be introduced into the processing tank 12 with a stable inflow amount without causing an inadvertent change in the inflow amount of the pure water or the HF aqueous solution into the processing tank 12. Can be flowed in.

Also, in the substrate processing apparatus 10, as shown in FIG. 5, the excess etching amount at the time of the pure water replacement and the etching shortage amount at the beginning of the substrate processing are matched by controlling the pure water flow rate at the time of the pure water replacement. It was Therefore, according to the substrate processing apparatus 10, high processing quality can be maintained by making the etching amount more uniform.

Although one embodiment of the present invention has been described above, the present invention is not limited to such an embodiment and can be implemented in various modes without departing from the scope of the present invention. Of course.

For example, the start of replacement of the diluted HF aqueous solution of pure water is detected by the HF passage detection sensor 33, but the following is performed so as to detect the start of replacement of the diluted HF aqueous solution without using the HF passage detection sensor 33. It can also be configured as follows.

At the design stage of the substrate processing apparatus 10, the effective pipeline area and pipeline length of the pure water supply pipeline 20 and the HF supply pipeline 28 are determined, so these design values and the flow rate detection sensor 2 are determined.
4 and the flow rate detected by the flow rate detection sensor 32, the time from the start of the mixing of the HF aqueous solution into the pure water supply pipe 20 to the arrival of the HF aqueous solution in the processing tank 12 (HF arrival time).
Can be calculated. Therefore, the time when the HF arrival time elapses after the HF aqueous solution is mixed into the pure water supply conduit 20 by the flow control valve 30 may be treated as the time to start the diluted HF aqueous solution replacement of pure water in the treatment tank 12. Specifically, the mixed supply time Ts in step S120 may be measured at the time when the HF arrival time elapses after the HF aqueous solution is mixed into the pure water supply conduit 20. With this configuration, the HF passage detection sensor 33 is not required, and the configuration can be simplified.

Further, in the above-mentioned embodiment, the case where the substrate is processed with the dilute aqueous solution of the single substrate processing liquid (HF aqueous solution) is explained. However, the substrate processing is performed with the dilute aqueous solution of the plurality of substrate processing liquids, for example, hydrogen peroxide. It goes without saying that the present invention can be applied to the case of processing a substrate with a diluted substrate processing liquid such as water or ammonia water. In this case, the concentration of each substrate processing liquid may be detected.

Further, in the above-described embodiment, the conduit is configured so that the HF aqueous solution is mixed into the pure water supply conduit 20, but as shown in FIG. 6, the pure water supply conduit 20 and the HF supply conduit 28 are provided.
It is also possible to individually configure and to reach the processing tank 12. In this case, the start of replacement of the diluted HF aqueous solution of pure water in the treatment tank 12 is determined as the opening of the pipeline by the flow rate control valve 30, so that the HF passage detection sensor 33 is unnecessary and the configuration can be simplified.

Further, in the above-mentioned embodiment, the structure in which pure water is supplied alone to replace the pure water inside the processing tank 12 to clean the substrate after the completion of the substrate dipping treatment in the diluted HF aqueous solution has been described. It is also possible to adopt a configuration in which the substrate W is taken out from the processing tank 12 or the diluted HF aqueous solution in the processing tank 12 is discharged after the substrate dipping treatment with the HF aqueous solution is completed. In addition, in the above-described embodiment, the configuration in which pure water is also supplied when the HF aqueous solution is supplied to the processing tank 12 has been described, but when the HF aqueous solution is supplied, the pure water supply is stopped and the processing tank is stopped. Of course, it can be applied to the case where the HF aqueous solution is diluted with the pure water in 12.

[0068]

As described above in detail, in the substrate processing apparatus according to the first aspect, even if the diluted preparation concentration of the substrate processing liquid changes every time the substrate is processed for some reason, the diluted preparation concentration is changed according to the change. The substrate immersion time with the substrate processing liquid having the concentration is determined, and when the determined substrate immersion time has elapsed after the substrate processing liquid replacement in the processing tank was started, the substrate immersion with the diluted substrate processing liquid is stopped. Therefore, claim 1
According to the described substrate processing apparatus, the substrate processing quality can be maintained by associating the diluted preparation concentration of the substrate processing liquid actually used for dipping the substrate with the substrate dipping time.
Moreover, in the substrate processing apparatus according to the first aspect of the present invention, even if the concentration of the substrate processing liquid storage tank is changed, the degree of processing in the immersion processing of the substrate, and thus the processing quality, can be maintained. Therefore, according to the substrate processing apparatus of the first aspect, it is not necessary to strictly control the concentration of the substrate processing liquid itself, and the handling thereof can be simplified.

In the substrate processing apparatus according to the second aspect, the immersion of the substrate in the diluted substrate processing liquid is stopped by replacing the diluted substrate processing liquid in the processing bath with pure water. Therefore, according to the substrate processing apparatus of the second aspect, since the substrate processing liquid is not left attached to the substrate after the substrate immersion processing, carelessness is required after the immersion processing with the substrate processing liquid having a diluted preparation concentration. The progress of substrate processing can be avoided. In addition, it is convenient for the subsequent process because it is cleaned with pure water after the replacement with pure water.

In the substrate processing apparatus according to the third aspect, the diluted preparation concentration is made uniform by supplying pure water and the substrate processing liquid from the bottom of the processing tank, and the diluted dilution of the substrate processing liquid overflows at the uniformed dilution concentration. Detect the concentration. Therefore, according to the substrate processing apparatus of the third aspect, the substrate immersion time can be determined by accurately detecting the diluted preparation concentration and accurately corresponding to the diluted concentration of the substrate processing solution and the substrate immersion time. It is possible to improve and maintain the processing quality of processing.

In the substrate processing apparatus according to the fourth aspect, the substrate immersion time corresponding to the change in the diluted preparation concentration of the substrate processing solution for each substrate processing is also adapted to the bath liquid temperature for each substrate processing. Therefore, according to the substrate processing apparatus of the fourth aspect, it is possible to suppress the fluctuation of the processing degree by the substrate processing liquid and to maintain and improve the substrate processing quality.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram schematically showing a configuration of a substrate processing apparatus 10 in which a substrate is immersed in a dilute hydrofluoric acid solution for etching.

FIG. 2 is a flowchart showing a substrate immersion processing routine performed by an electronic control unit 40.

FIG. 3 is a timing chart for explaining the contents of processing in a substrate dipping processing routine.

FIG. 4 is a graph for explaining the contents of processing in a substrate dipping processing routine.

FIG. 5 is an explanatory diagram for explaining the content of processing in a substrate immersion processing routine.

FIG. 6 is a schematic configuration diagram schematically showing the configuration of another embodiment of the substrate processing apparatus 10.

[Explanation of symbols]

 10 ... Substrate processing apparatus 12 ... Processing tank 14 ... Overflow tank 15 ... HF concentration detection sensor 16 ... Nozzle 17 ... Temperature sensor 18 ... Pure water supply device 20 ... Pure water supply pipeline 22 ... Flow control valve 24 ... Flow rate detection sensor 26 ... HF aqueous solution storage tank 28 ... HF supply pipe 30 ... Flow control valve 32 ... Flow detection sensor 33 ... HF passage detection sensor 34 ... Nitrogen gas supply device 36 ... Nitrogen gas supply pipe 38 ... Flow control valve 40 ... Electronic control device 42 ... CPU 44 ... ROM 46 ... RAM 48 ... Timer W ... Board

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Yusuke Muraoka 322, Fukumi-ku, Fushimi-ku, Kyoto, Furukawa-cho, Dainichi Screen Manufacturing Co., Ltd. Rakusai Factory

Claims (4)

[Claims] 1. A processing tank for accommodating a substrate, receiving pure water and a substrate processing liquid and immersing the substrate in a dilute solution of the substrate processing liquid for processing, and pure water in the processing tank. Pure water supply means for supplying, substrate processing liquid supply means for supplying the substrate processing liquid to the processing bath, and the pure water and substrate processing liquid by controlling the substrate processing liquid supply means and the pure water supplying means. And the supply to the processing bath are stopped, and the pure water in the processing bath is replaced with the substrate processing liquid so that the bath liquid overflows from the processing bath after filling the processing bath with pure water. And a control unit for diluting and adjusting the substrate processing liquid, wherein the control unit is configured to replace pure water in the processing tank with the substrate processing liquid supplied by the substrate processing liquid supply unit. A clock that counts the time elapsed since it was started Unit, a storage unit that stores the concentration of the substrate processing liquid and the substrate immersion time of the substrate in the processing tank in association with each other, a substrate processing liquid concentration detection unit that detects the concentration of the substrate processing liquid, and the substrate Immersion time for determining the substrate immersion time with the diluted substrate treatment liquid according to the concentration of the substrate treatment liquid at the time of preparation of the dilution of the substrate treatment liquid detected by the treatment liquid concentration detector and the storage result of the storage unit A substrate processing apparatus, comprising: a determination unit; and a substrate immersion stopping unit that stops substrate immersion in the diluted substrate processing liquid when the time counting unit measures the elapsed time of the determined substrate immersion time. . 2. The substrate processing apparatus according to claim 1, wherein the substrate immersion stopping unit controls the pure water supply unit when the time counting unit measures the elapsed substrate immersion time. A substrate processing apparatus for replacing the diluted substrate processing liquid in the processing tank with pure water. 3. The substrate processing apparatus according to claim 1, wherein the pure water supply means and the substrate processing liquid supply means supply pure water or a substrate processing liquid to the processing bath from the bottom thereof. The substrate processing liquid concentration detector detects a substrate processing liquid concentration in a bath liquid overflowing from the processing bath. 4. The substrate processing apparatus according to claim 1, wherein the temperature detecting unit detects a temperature of a liquid in the bath in the processing bath, and the bath in which the determined substrate immersion time is detected. A substrate processing apparatus comprising: an immersion time correction unit that corrects according to the internal liquid temperature.