JP4052725B2 - Chemical supply device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a chemical solution supply apparatus that can improve safety more particularly when automatically supplying from a chemical solution tank on a supply source side to a plurality of processing tanks equipped with a measuring tank.
[0002]
[Prior art]
In chemical supply equipment indispensable for semiconductor manufacturing, etc., the number of processing tanks that treat wafer surfaces using chemicals such as hydrogen peroxide and sulfuric acid gradually increases as the manufacturing scale increases and performance increases ( Use points are around 10 to 30). In the current chemical solution supply apparatus, the chemical solution tank on the supply source side and each processing tank are connected via a common pipe and an on-off valve on each processing tank side, and a chemical request signal from each processing tank side is received. On the basis of this, all the operations are performed almost automatically by controlling the opening / closing valve on each processing tank side and the liquid feeding means of the chemical tank by the operation control unit. This point will be outlined with reference to FIG. 1 to which the present invention is applied. On the processing tank side, when the used chemical liquid is discarded and newly required, a chemical request signal is sent to the operation control unit, and a stop signal is sent when the measuring tank of the processing tank reaches a predetermined liquid level. When the operation control unit receives the chemical request signal, it opens the open / close valve of the corresponding treatment tank and sends a signal to start the liquid supply means of the chemical tank to be used. Stop the liquid means.
[0003]
In such a chemical supply device, as the drive capability increases and the automatic operation progresses, if an abnormality such as device drool occurs, secondary troubles will occur due to the outflow of excessive chemicals and scattering of chemicals in addition to the occurrence of major accidents and disasters, etc. Safety measures are more important because of the occurrence of In the conventional chemical solution supply apparatus, for example, on the piping part side, in order to prevent liquid leakage from the piping, the configuration of the piping itself, a leak sensor, and the like are attached to detect the liquid leakage. On the processing tank side, the supply chemical solution is monitored by a liquid level sensor, and when the liquid level reaches a predetermined level, the on-off valve is automatically closed. On the chemical supply side, a time-out function is provided to prevent excessive chemical supply caused by an abnormality such as a request signal, and the supply operation state of the liquid supply means on the chemical tank side has passed a preset time set manually. Then, it is forced to stop.
[0004]
[Problems to be solved by the invention]
In the conventional time-out function, for example, when there are 10 use points, that is, 10 processing tanks, at least 2 when supplying to one processing tank based on the maximum number of requests 10 simultaneously supplied to each processing tank. It is necessary to allow for ~ 5 times the time. This set time is set to a longer time in consideration of the progress of clogging such as a filter. Therefore, even if the conventional time-out function stops the supply of chemicals to the treatment tank based on this, there is a long time lag from when the abnormality occurs until it stops, so it can prevent catastrophes. However, damage such as equipment damage due to excessive chemical solution on the treatment tank side could not be avoided, and it was not satisfactory as a safety type.
[0005]
The present invention eliminates the problems of the above-described conventional automatic chemical solution supply device, enables automatic supply of chemical solution more safely, and can safely prevent relatively minor damage as well as catastrophe. To provide an apparatus. Other objects will be clarified sequentially in the contents described below.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a common pipe and each of the above-described chemical tanks between a supply source side chemical tank, a measuring tank, and a plurality of processing tanks equipped with a liquid level sensor for monitoring the liquid level of the chemical liquid in the tank. Connected via an open / close valve on the treatment tank, controls the open / close valve on the treatment tank based on a signal from the liquid level sensor on the treatment tank, and supplies the chemical liquid to the treatment tank by the liquid supply means of the chemical tank In the chemical supply device
The supply time measuring unit that measures the chemical solution supply time from the start to the stop of the chemical solution supply for each treatment tank, and the simultaneous supply number that measures the number of treatment tanks that supply the chemical solution simultaneously for each treatment tank that is supplying the chemical solution The limit supply time Trk from the measurement unit, the storage unit for storing the chemical solution supply time corresponding to the simultaneous supply number for each processing tank, and the storage unit data and the simultaneous supply number during measurement for each processing tank Is calculated by the following formula , and includes a calculation determination unit that compares the chemical supply time during measurement with the limit supply time, and before receiving the stop signal of the liquid level sensor that detects the supply stop time, the chemical supply time When the condition of (T)> limit supply time (Trk) is satisfied, it is determined that an abnormality has occurred, and the liquid supply means of the chemical tank can be stopped.
Trk = T 0 + (R × n) + k
Here, in the above equation, T 0 is the required chemical solution supply time in the case of single supply to the treatment tank, R is a constant calculated from the actual data and equation, n is the average number of simultaneous supplies, and k is a safety factor. It is a constant that is set appropriately.
[0007]
In this structure, the supply time measurement unit measures the chemical solution supply time from the start to the stop of the chemical solution for each processing tank. The simultaneous supply number measuring unit measures the number of processing tanks that supply chemical solutions simultaneously, that is, the simultaneous supply number, while supplying chemical solutions to one processing tank. This measurement is performed for each processing tank, and this simultaneous supply number is processed as an average value at the time of measurement.
The storage unit stores the required chemical solution supply time corresponding to the number of simultaneous supply for each processing tank by initial input. This initial input data is set by statistically processing past actual product data, or appropriate data with sufficient safety in mind, in which case it is more appropriate for the subsequent actual product data. Is to be modified. Even in the former case, it is preferable that the actual product data is similarly corrected.
The calculation determination unit moves a limit chemical solution supply time calculation program (Equation (2) in paragraph 0015) to stop the supply of the chemical solution for safety control based on the storage unit data for each processing tank, The limit chemical supply time (limit supply time Trk) corresponding to the number of simultaneous supplies is estimated, and the chemical supply time (T) being measured is the limit chemical supply time (Trk; hereinafter, this may be abbreviated as the limit supply time). ), A command is issued to stop the operation of the liquid supply means of the chemical tank.
Therefore, in this structure, the limit chemical supply time (limit supply time Trk) is managed for each treatment tank corresponding to the number of simultaneous supplies, so that the chemical supply stop function as safety control is activated at an appropriate time. In addition, damage such as damage to equipment due to excessive supply of chemicals can be minimized.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. This embodiment is a preferred specific example of the present invention and does not limit the scope of the present invention.
[0009]
FIG. 1 schematically shows a chemical supply plant in which the present invention is adopted. This chemical solution supply plant is incorporated in semiconductor manufacturing equipment, and is equipped with a chemical solution supply unit 1 that continuously supplies chemical solutions such as hydrogen peroxide and sulfuric acid, and a processing tank group that processes workpieces such as semiconductor substrates. Operation control that opens the on / off valve on the processing tank side and activates the chemical supply section 1 in a supply start state in response to a chemical request signal from the processing tank No1 to Non side of the processing section 2 Part 3.
[0010]
The chemical liquid supply unit 1 includes a chemical liquid tank 4 and a compressed gas source 5 for introducing an inert gas such as nitrogen into the chemical liquid tank 4. The compressed gas source 5 sends an inert gas such as nitrogen gas to the chemical tank 4 at a high pressure via a pipe 6 and an automatic on-off valve 7 such as a solenoid valve. The chemical liquid tank 4 has an auxiliary chemical liquid tank 4b together with the main chemical liquid tank 4a, and these are installed in a tank chamber that is cut off from the outside by a partition wall (not shown). Switching between the two chemical tanks 4a and 4b is performed by an operator. Each of the chemical liquid tanks 4 a and 4 b has a gas introduction connecting portion 8 a that is connected to the distal end side of the pipe 6, and a chemical liquid derivation connecting portion 8 b that is connected to the pipe 10 disposed toward the processing portion 2. And have. Further, on the tank side of the pipe 10, an automatic on-off valve 11 such as an electromagnetic valve and a filtration unit 12 with a built-in filter are interposed in a pipe line. Therefore, the chemical solution in the chemical solution tank 4 is pumped to the pipe 10 side by the operation of the on-off valves 7 and 11 and stopped on the contrary. Therefore, in this embodiment, the on-off valves 7 and 11 serve as liquid feeding means for the chemical tank 4.
[0011]
The main chemical liquid tank 4a and the auxiliary tank 4b are switched by closing the on-off valve 9a interposed in the pipe portion connecting the tanks 4a, 4b to the pipe 6 and opening the on-off valve 9b. Moreover, the on-off valve 13a interposed in the pipe part connected to the piping 10 is closed, and the on-off valve 13b is opened. The main chemical liquid tank 4a after switching is replaced with a new chemical liquid tank, that is, the next auxiliary tank. This replacement work is performed via the connecting portions 8a and 8b.
[0012]
The processing unit 2 is several tens of meters or more away from the chemical solution supply unit 1, and various processing tanks No 1 to Non (n is usually 10 to 30) equipped with a measuring tank are installed along the common pipe 10. This is where the wafers are surface-treated independently or continuously in the treatment tanks No1 to Non. The arrangement of the processing tanks No1, No2,... Non is appropriately designed in a state suitable for the work contents with respect to the common pipe 10.
[0013]
The common matters of the treatment tanks No1 to Non all have at least a liquid level sensor that detects the liquid level of the chemical solution in the tank, an on-off valve, and the like. Each liquid level sensor monitors the liquid level of the chemical liquid in the tank, for example, sends a command to detect when the chemical liquid in the tank is completely discarded and start supplying the chemical liquid, and closes the valve of the discharge unit. A chemical solution request signal is sent to the controller 3 to supply a new chemical solution, or a command or the like is sent to detect the supply stop time and close the corresponding on-off valve. Each on-off valve is an automatic type such as a solenoid valve, and opens and closes between the pipes 10 to supply a chemical solution into the tank. And the mechanism part of each said liquid level sensor and each on-off valve, and the operation control part 3 side are connected by the signal wire | line 15.
[0014]
When the operation control unit 3 receives a chemical request signal from the processing unit 2 side, the operation control unit 3 sends a signal to open the on-off valves 7 and 11 that are liquid supply means of the chemical tank 4, and opens and closes when all the request signals are lost. It is almost the same as the prior art in that the valves 7 and 11 are closed. The difference is that the number of simultaneous supply that is the number of processing tanks that have a safety control unit 16 and supply the chemical solution request signal to each of the processing tanks No 1 to Non via the safety control unit 16 at the same time. This is based on management. The safety control unit 16 includes a simultaneous supply number measurement unit 17 and a supply time measurement unit 18, a calculation determination unit 19, a storage unit 20 connected to the calculation determination unit 19, an input unit 21, an alarm unit 22, and the like. Yes.
[0015]
Here, the storage unit 20 stores a required chemical solution supply time, which is an actually measured value corresponding to the number of simultaneous supplies for each processing tank, and an expression (1) representing a relationship between the two.
Tr = T0 + (R × n) Formula (1)
In Formula (1), Tr is a required chemical | medical solution supply time in case the simultaneous supply number is n. T0 is the number of simultaneous supplies n = 0, that is, the required chemical solution supply time in the case of single supply to the treatment tank. R is a constant. This constant R is calculated from actually measured data and a formula in the storage unit 20. Further, the storage unit 20 stores an equation (2) for managing the limit chemical solution supply time Trk for stopping the supply of the chemical solution for safety control.
Trk = T0 + (R × n) + k Equation (2)
In equation (2), k is a safety factor time added to the required chemical solution supply time T0 + (R × n) when the number of simultaneous supplies is n, and is a constant set as appropriate.
The operation determination unit 19, simultaneously supplying the number of which is measured by the co-feed speed meter measuring unit 17 (average value of n values far) was treated by the equation (2), estimate the corresponding limit supply time (Trk) Then, the supply time (T) measured by the supply time measuring unit 18 is compared with the limit supply time, and the operation control is performed when the supply time (T) being measured exceeds the limit supply time (Trk). A stop signal (closed signal) is sent to the liquid feeding means (open / close valves 7, 11) of the chemical tank 4 via the unit 3.
[0016]
And the safety control part 16 controls each part with the following flows. FIG. 2 summarizes the flow of the control in a flowchart, and will be described with reference to FIG. When the chemical solution request signal is sent from the processing unit 2 side via the signal line 14, the simultaneous supply number measurement unit 17 counts it as needed and transmits it to the supply time measurement unit 18 and the operation determination unit 19. . This is performed for each processing tank. When the simultaneous supply number measuring unit 17 receives the first request signal, it sends a valve opening signal to the on-off valves 7 and 11 as the liquid feeding means via the operation control unit 3 to open the on-off valves 7 and 11. Switch to state. Thereby, the chemical solution in the chemical solution tank 4 is pumped to the pipe 10, and the chemical solution is supplied to the corresponding treatment tank via the pipe 10 and the corresponding on-off valve.
[0017]
Based on the signal from the simultaneous supply number measurement unit 17, the supply time measurement unit 18 measures the chemical solution supply time (T) in which the chemical solution is actually supplied for each processing tank, and supplies it to the calculation determination unit 19. It is transmitted as data for each processing tank.
[0018]
The calculation determination unit 19 moves a limit chemical solution supply time calculation program for stopping chemical supply for safety control on the basis of the storage unit data for each processing tank, and the limit chemical solution corresponding to the number of simultaneous supplies being measured. The supply time (limit supply time Trk) is estimated, and it is determined whether or not the chemical solution supply time (T) being measured exceeds the limit supply time (Trk). This determination is performed for each processing tank until the condition of chemical solution supply time (T)> limit supply time (Trk) is not satisfied and a stop signal is received. This is a regular management route. However, when the condition is satisfied before receiving the stop signal, this is determined as an abnormality, and the calculation determination unit 19 is based on the determination result, and the on-off valve 7 which is a liquid feeding means via the operation control unit 3. , 11 is issued to switch the open / close valves 7, 11 to the closed state. At the same time, an alarm sound is output via the alarm unit 22. This is the management route at the time of abnormality. The determination of the occurrence of the abnormality is made for each processing tank, and the limit supply time (Trk) is estimated for each processing tank based on the management formula (2) corresponding to the average value of the simultaneous supply number n during measurement. Since it is judged, appropriate management becomes possible.
[0019]
In addition, when the chemical solution supply is stopped for each treatment tank through the regular management route, the supply time T measured by the supply time measuring unit 18 is measured by the simultaneous supply number measuring unit 17 as the required chemical solution supply time Tr. The number of simultaneous supplies is recorded in the storage unit 20. Then, for each predetermined period, the simultaneous supply number and the required chemical solution supply time, which have been stored in the storage unit 20 and used for calculating the limit chemical solution supply time, are corrected with new data. This advantage is that, when the chemical solution supply device 1 is continuously used, for example, even if the filtration unit 12 with a built-in filter is gradually clogged and the chemical solution is pumped from the chemical solution tank 4 with the same pressure, As the clogging progresses, the supply pressure or the supply flow rate decreases. Such a situation is to be reflected in management.
[0020]
【The invention's effect】
As described above, the chemical supply apparatus of the present invention is safe because, for example, even if the number of treatment tanks, that is, the use point is increased to 30, the limit chemical liquid supply time is managed according to the number of simultaneous supply for each treatment tank. The chemical supply stop function as a control is activated at an appropriate time, and damage such as damage to devices due to excessive chemical supply can be further minimized, and the device reliability can be improved.
[Brief description of the drawings]
FIG. 1 is a configuration diagram schematically showing an entire chemical solution supply apparatus to which the present invention is applied.
FIG. 2 is a diagram conceptually summarizing the control procedure of the safety control unit in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 is chemical | medical solution supply part 2 is processing part 3 is operation control part 7 is on-off valve (liquid supply means of chemical | medical solution tank)
11 is an on-off valve (solution feeding means for the chemical tank)
16 is a safety control unit 17 is a simultaneous supply number measurement unit 18 is a supply time measurement unit 19 is a calculation determination unit 20 is a storage unit

Claims (1)

Connects between the chemical tank on the supply side and the measuring tank and multiple processing tanks equipped with a liquid level sensor that monitors the liquid level of the chemical liquid in the tank via a common pipe and the open / close valve on each processing tank. In the chemical supply apparatus for controlling the on-off valve on the processing tank side based on the signal from the liquid level sensor on the processing tank side and supplying the chemical liquid to the processing tank by the liquid feeding means of the chemical tank,
A supply time measuring unit that measures the chemical solution supply time from the start of supply of chemical solution to the stop for each treatment tank,
A simultaneous supply number measuring unit that measures the number of treatment tanks supplying chemical solutions at the same time for each treatment tank supplying chemical solutions,
The storage unit for storing the chemical solution supply time corresponding to the number of simultaneous supply for each processing tank, and the limit supply time Trk from the storage unit data and the number of simultaneous supply during measurement for each processing tank by the following formula A calculation determination unit that estimates and compares the chemical supply time during measurement with the limit supply time,
When the condition of chemical solution supply time (T)> limit supply time (Trk) is satisfied before receiving the stop signal of the liquid level sensor that detects the supply stop time, this is determined as the occurrence of abnormality, and the chemical solution A chemical supply apparatus characterized in that the liquid supply means of the tank can be stopped.
Trk = T 0 + (R × n) + k
Here, in the above equation, T 0 is the required chemical solution supply time in the case of single supply to the treatment tank, R is a constant calculated from the actual data and equation, n is the average number of simultaneous supplies, and k is a safety factor. It is a constant that is set appropriately.

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