JPH0945656A - Semiconductor manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor manufacturing apparatus by which the change in the concentration of a cleaning liquid is prevented, by which the degradation of the cleaning liquid is prevented, by which the cleaning liquid is stabilized automatically for a long period. SOLUTION: A concentration monitor 13 always monitors the concentration of a chemical liquid inside a cleaning tank, a computing operation is performed by a concentration computing part 20, and a chemical-liquid concentration value is output to a central processing part 28. The central processing part 28 compares a computation results with data in the prescribed range of a concentration stored in a storage part 24. When the concentration of the chemical liquid is higher than the prescribed concentration, a control signal is output to a valve control part 22, a valve 9a is opened, and pure water is supplied to a cehmical liquid tank. When the concentration of the chemical liquid is lower than the prescribed concentration, a control signal is output to a valve control part 21, a valve 8a is opened, a chemical liquid is supplied to the cehmical liquid tank, and the chemical liquid is kept at the prescribed concentration. When the chemical liquid tank is nearly filled up, a control signal is output to a heater control part 27, a heater 7 is operated, water is evaporated, and the concentration of the chemical liquid is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus, and more particularly to a technique effectively applied to the concentration control of a chemical solution in a semiconductor wafer wet cleaning apparatus or wet etching apparatus.

[0002]

2. Description of the Related Art According to a study made by the present inventor, a liquid such as a chemical liquid is used to clean a semiconductor wafer which is an object to be processed.
In order to improve the cleaning effect, the semiconductor wafer is cleaned by spraying a chemical solution stored in a chemical solution tank kept at a constant temperature by a heater or the like onto a rotating semiconductor wafer.

Further, the chemical liquid after cleaning the semiconductor wafer is collected, stored again in the storage tank, and reused.

As an example in which a cleaning device of this kind is described in detail, Kogyo Kogyo Kaisha, Ltd., November 25, 1994, "VLSI Manufacturing / Testing Equipment Guidebook <1995 Edition>" Masashi Oshima (ed. ), P103 to P1
09, which describes the configuration and type of a cleaning / drying apparatus used for manufacturing a semiconductor device.

[0005]

However, the present inventor has found that the above-described cleaning device has the following problems.

That is, the temperature of the chemical solution itself is changed and the chemical solution deteriorates due to long-term temperature control by a heater or the like provided in the chemical solution tank and mixing of deionized water that flushes the chemical solution when the cleaning solution is collected after cleaning. Therefore, the stability of the drug solution becomes a problem.

Further, since the chemical liquid is replaced with a new chemical liquid each time the concentration or deterioration of the chemical liquid occurs, the consumption amount of the chemical liquid becomes enormous and the cost also increases significantly.

An object of the present invention is to provide a semiconductor manufacturing apparatus capable of preventing the concentration change and deterioration of the cleaning liquid and automatically stabilizing the cleaning liquid for a long period of time.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0010]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, in the semiconductor manufacturing apparatus of the present invention, the concentration detecting means for detecting the concentration of the chemical liquid in the chemical liquid tank for storing the chemical liquid, and whether the chemical liquid concentration detected by the concentration detecting means is the prescribed chemical liquid concentration. Concentration control means for determining whether or not the concentration of the chemical liquid in the chemical liquid tank is constant is provided.

Further, in the semiconductor manufacturing apparatus of the present invention, the concentration detecting means calculates the chemical concentration value based on the detection means for detecting the chemical concentration in the chemical tank and the signal output from the detecting means. First concentration limiting means for limiting the flow rate of the first liquid for increasing the concentration of the chemical liquid supplied to the chemical liquid tank, and second concentration reduction means for decreasing the concentration of the chemical liquid supplied to the chemical liquid tank. Second to limit the flow rate of liquid
And a concentration control means for comparing the chemical concentration value output from the calculating means with a prescribed chemical concentration value and outputting a predetermined control signal, and a control signal output from the concentration control means. The flow rate control means controls the first flow rate limiting means and the second flow rate limiting means on the basis of the flow rate controlling means.

Further, in the semiconductor manufacturing apparatus of the present invention, the concentration control means includes heating means for heating the chemical liquid in the chemical liquid tank,
And heating control means for controlling the heating means based on the control signal output from the concentration control means.

Further, the semiconductor manufacturing apparatus of the present invention comprises concentration detecting means for detecting the concentration of the chemical liquid in the chemical liquid tank for storing the chemical liquid,
Concentration calculation means for calculating the concentration of the chemical solution based on the signal output from the concentration detection means, and processing control means for automatically setting the processing time of the object to be processed based on the calculation result output from the concentration calculation means And a flow rate limiting means for limiting the flow rate of the chemical injected to the object to be treated, and a flow rate controlling means for controlling the flow rate limiting means based on a control signal output from the processing control device.

[0015]

According to the above-described semiconductor manufacturing apparatus of the present invention, the concentration of the chemical liquid in the chemical liquid tank is constantly monitored by the detecting means, and the concentration control means calculates the chemical liquid concentration value calculated by the calculating means and the predetermined chemical liquid. When the concentration of the chemical liquid is compared with the concentration value and the concentration of the chemical liquid is lower than the preset concentration, the first liquid which increases the chemical liquid concentration by outputting a control signal to the flow rate control means to control the first flow rate limiting means. Is supplied to the chemical solution tank or a control signal is output to the heating control means to control the heating means, and the chemical solution is heated to evaporate the water in the chemical solution tank to increase the chemical solution concentration. If the chemical concentration is higher than a preset concentration, a control signal is output to the flow rate control means to control the second flow rate limiting means to supply the second liquid whose chemical concentration is lowered to the chemical bath. It is thereby possible to automatically continuously constant chemical concentration in the chemical tank.

Further, according to the above-described semiconductor manufacturing apparatus of the present invention, the concentration of the chemical liquid in the chemical liquid tank is monitored by the concentration detection, and the concentration calculation means calculates the chemical concentration value based on the signal output from the concentration detection means. And the processing control means automatically sets the processing time of the object to be processed based on the calculation result, and the flow rate controlling means is a flow rate controlling means for restricting the flow rate of the chemical injected to the object to be processed during cleaning. Since the cleaning is performed while being controlled by the method, the object to be processed can be stably processed even if the chemical concentration in the chemical bath changes.

[0017]

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

(Embodiment 1) FIG. 1 is a structural explanatory view of a cleaning apparatus according to Embodiment 1 of the present invention, and FIG. 2 is Embodiment 1 of the present invention.
6 is a block diagram of a cleaning chemicals concentration control unit according to FIG.

In the first embodiment, a cleaning apparatus (semiconductor manufacturing apparatus) 2 for cleaning a semiconductor wafer (object to be processed) 1 by injecting a chemical solution or pure water so as to surround the semiconductor wafer 1 being cleaned. Cup 3 which is a simple cylindrical container
Is provided.

A stage (not shown) for holding the back surface of the semiconductor wafer 1 and rotating the semiconductor wafer 1 is provided at the center of the cup 3, and the cleaning liquid after use is provided at the bottom of the cup 3. The drains 3a and 3b for discharging the chemical solution or pure water rinsed after cleaning are provided.

The drain 3a is connected to the pipe 4 and the drain 3b is connected to the pipe 5. Further, the pipe 4 is connected to a chemical liquid tank 6 provided in the cleaning device 2 for storing a chemical liquid via a filter (not shown) for removing foreign matters, and the pipe 5 is a processing tank (not shown) for treating waste liquid. Connected with.

Further, the drains 3a, 3b are provided with open / close valves (not shown) such as solenoid valves, and the chemical liquid to be recovered after use is recovered in the chemical liquid tank 6 by opening the open / close valve of the drain 3a. Therefore, the discarded chemical liquid is treated as a waste liquid by opening the opening / closing valve of the drain 3b.

Further, the chemical liquid tank 6 is provided with a heater (heating means) 7 for heating the chemical liquid in the chemical liquid tank 6 to a constant temperature.

Further, in the upper part of the chemical liquid tank 6 in the cleaning device 2, the chemical liquid (first liquid) and pure water (second liquid) are provided.
Are provided respectively, and these pipes 8 and 9 are connected to the chemical liquid tank 6,
Reference numeral 9 is a valve (first flow rate limiting means) 8a, such as a solenoid valve, for limiting the supply amount of the chemical liquid and pure water.
A valve (second flow rate limiting means) 9a is provided.

Further, the cleaning apparatus 2 is provided with a pipe 10 near the bottom of the chemical liquid tank 6, and a pump 11 for constantly circulating the chemical liquid at a predetermined position of the pipe 10, and removing foreign matters in the chemical liquid. A concentration monitor (detection means) 13 such as a pH sensor for monitoring the concentration of the filter 12 and the chemical liquid is provided.

Further, the cleaning apparatus 2 is provided with a pump 14 for injecting the chemical liquid in the chemical liquid tank 6 at the time of cleaning the semiconductor wafer 1, and the chemical liquid is supplied from the nozzle 15a at the tip end through a pipe 15 connected to the chemical liquid tank 6. Are sprayed onto the surface of the semiconductor wafer.

The pipe 15 is also provided with a filter 16 for removing foreign substances in the chemical liquid, and valves 17, 18 such as electromagnetic valves for limiting the supply amount of the chemical liquid.

The cleaning device 2 includes the heater 7, the valves 8a and 9a, the valves 17 and 18, and the like.
A cleaning chemical concentration control unit 19 that controls all of the above is provided.

Next, as shown in FIG. 2, the cleaning chemical solution concentration control section 19 calculates the concentration of the chemical solution based on the signal output from the concentration monitor 13, and the concentration calculation section (calculation means) 20.
And valves 8a and 9a for limiting the flow rates of the chemical liquid and the pure water
A valve control section (flow rate limiting means) 21, a valve control section (flow rate limiting means) 22, and a valve opening / closing section (not shown) that controls the opening / closing of the valves 17 and 18 (FIG. 1). There is.

The density monitor (detection means) 13 and the density calculation section 20 constitute the density detection means NK1.

Further, the cleaning chemical concentration control section 19 is provided with an input section 23 such as a keyboard for inputting predetermined data, and the specified concentration data of the chemical solution input from the input section 23. A storage unit 24 for storing is provided.

Further, the cleaning chemical concentration control unit 19 is provided with a display unit 26 such as a monitor for displaying input data such as a character string based on the signal of the display control unit 25, and this display unit 26. Is connected to the display control unit 25.

The cleaning chemical concentration control unit 19 is a heater control unit (heating control means) for controlling the heater 7 described above.
27 are provided.

A central processing unit (concentration control means) 28 is provided in the cleaning chemical concentration control unit 19, and these concentration calculation unit 20, valve control units 21, 22 and storage unit 2 are provided.
4. The display control unit 25 and the heater control unit 27 are connected to the central processing unit 28, and all controls such as the control of the cleaning operation in the cleaning device 2 and the concentration control of the chemical liquid are performed.

Also, the heater 7 and the valves 8a and 9
A, the valve control units 21 and 22, the heater control unit 27, and the central processing unit 28 constitute a concentration control unit NC1.

Next, the operation of this embodiment will be described.

First, before cleaning the semiconductor wafer 1, the valve 17 is in the open state and the valve 18 is in the closed state, so that the pump 14 is operating, so that the chemical solution is stored in the chemical solution tank 6. It circulates. The pump 11 is also operating at the same time, and the chemical liquid is constantly circulated in the chemical liquid tank 6.

When the semiconductor wafer 1 is mounted on a stage and the stage is rotated to clean the semiconductor wafer 1, the central processing unit 28 outputs a control signal to the valve opening / closing unit to open the valve 18 and open the valve 17. By closing, the chemical solution is sprayed from the nozzle 14a onto the semiconductor wafer 1 for cleaning.

At this time, the opening / closing valve provided in the drain 3a is opened and the chemical liquid is collected in the chemical liquid tank 6. After that, when the cleaning is completed, a rinse with pure water is performed, and the semiconductor wafer 1 is dried in the drying process.

The pure water in the rinse is treated as a waste liquid by opening the opening / closing valve of the drain 3b.

Next, the concentration monitor 13 constantly monitors the concentration of the chemical liquid in the chemical liquid tank 6 regardless of whether the semiconductor wafer 1 is being cleaned, and the concentration monitor 12 outputs the concentration. The signal is input to the concentration calculation unit 20, the concentration in the chemical solution is calculated, and the calculation result is output to the central processing unit 28.

Then, the central processing unit 28 compares the calculation result with the data of the specified concentration of the chemical liquid stored in the storage unit 24, and the chemical liquid concentration in the chemical liquid tank 6 falls within the specified range. When it becomes higher or lower than the data, a predetermined control signal is output to the valve control units 21 and 22 or the heater control unit 27.

For example, when the central processing unit 28 determines that the chemical liquid in the chemical liquid tank 6 becomes higher than the specified concentration, the central processing unit 28 outputs a control signal to the valve control unit 22 and based on the control signal. The valve control unit 22 opens the valve 9a to supply pure water to the chemical bath 6.

When the concentration of the chemical solution reaches the specified concentration, the central processing unit 28 again outputs a control signal to the valve control unit 22 to close the valve 9a and stop the pure water supply.

Next, when the central processing unit 28 determines that the concentration of the chemical solution becomes lower than the prescribed concentration, the central processing unit 2
8 outputs a control signal to the valve control unit 21, and the valve control unit 21 opens the valve 8a based on the control signal to supply the chemical liquid to the chemical liquid tank 6.

When the chemical liquid tank 6 is almost full and the chemical liquid cannot be supplied, the central processing unit 28 outputs a control signal to the heater control unit 27, and the heater control unit 27 causes the heater 7 to operate based on the control signal. Is heated to evaporate the water and increase the concentration of the drug solution.

Further, the heating by the heater 7 and the supply of the chemical solution by opening the valve 8a may be simultaneously performed.

When the concentration of the chemical liquid reaches the specified concentration, the central processing unit 28 outputs a control signal to the valve control unit 21 or the heater control unit 27 again to stop the supply of the chemical liquid or the heating by the heater 7.

Further, the amount of the chemical liquid in the chemical liquid tank 6 can be determined by, for example, a liquid level sensor (not shown) or the like.
8 performs detection, and when the chemical liquid is filled above a predetermined liquid level, heating is performed by the heater 7, and below that, the chemical liquid is supplied.

Thus, according to the first embodiment, the cleaning liquid chemical concentration control unit 19 can constantly keep the liquid chemical concentration in the liquid chemical bath 6 constant, and the cleaning effect can be made uniform.

Further, since the chemical solution can be constantly maintained at a constant concentration, it becomes unnecessary to dispose of the chemical solution due to the change in the concentration of the chemical solution in the chemical solution tank 6, and the cost of the chemical solution can be greatly reduced.

(Embodiment 2) FIG. 3 is a structural explanatory view of a cleaning apparatus according to Embodiment 2 of the present invention, and FIG. 4 is Embodiment 2 of the present invention.
6 is a block diagram of a cleaning chemicals concentration control unit according to FIG.

In the second embodiment, the cleaning apparatus 2 for cleaning the semiconductor wafer 1 by spraying the chemical liquid or the pure water is the same as the first embodiment.
A cup 3 which is a cylindrical container that encloses the semiconductor wafer 1 is provided, and a stage (not shown) that holds the back surface of the semiconductor wafer 1 and rotates the semiconductor wafer 1 is provided at the center of the cup 3. Has been.

At the bottom of the cup 3, drains 3a and 3b for discharging the chemical liquid or pure water which is the cleaning liquid after use.
The drain 3a is connected to the pipe 4 and the drain 3b is connected to the pipe 5.

Further, the pipe 4 is connected to a chemical liquid tank 6 for storing the chemical liquid provided in the cleaning device 2 via a filter (not shown) for removing foreign matters, and the pipe 5 is a processing tank (FIG. (Not shown) connected.

Further, the drains 3a and 3b are provided with open / close valves (not shown) such as solenoid valves, and when collecting the used chemical liquid, the open / close valve of the drain 3a is opened to collect in the chemical liquid tank 6, Others are treated as waste liquid by opening the opening / closing valve of the drain 3b.

Further, the cleaning device 2 is provided with a pipe 10 near the bottom of the chemical liquid tank 6, and a pump 11 for constantly circulating the chemical liquid at a predetermined position of the pipe 10, and removing foreign matters in the chemical liquid. A filter 12 and a concentration monitor 13 such as a pH sensor for monitoring the concentration of the chemical liquid are provided.

Further, the cleaning apparatus 2 is provided with a pump 14 for injecting the chemical solution in the chemical solution tank 6 at the time of cleaning the semiconductor wafer 1, and the chemical solution is supplied from the nozzle 15a at the tip end through a pipe 15 connected to the chemical solution tank 6. Is to be jetted.

Further, the pipe 15 is also provided with a filter 16 for removing foreign substances in the chemical solution, a valve (flow rate restricting means) 17a such as an electromagnetic valve for restricting the supply amount of the chemical solution, and a valve (flow rate restricting means) 18a. It is provided.

The cleaning device 2 includes valves 17a,
A cleaning control unit 29 that controls all of the cleaning device 2 such as 18a is provided.

This cleaning control means 29 is used for the concentration monitor 13
A concentration calculating section (concentration calculating means) 30 for calculating the concentration value of the chemical solution based on a signal output from the valve, and a valve control section (flow rate controlling means) for controlling opening / closing of the valves 17a, 18a for limiting the flow rates of the chemical solution and pure water. ) 21a, a valve control section (flow rate control means) 22a, and a central processing section (processing control means) 31 which determines an optimum cleaning time and controls all the cleaning apparatus 2.

Next, the operation of this embodiment will be described.

First, before cleaning the semiconductor wafer 1, the valve 17 is in the open state and the valve 18 is in the closed state, and the pump 14 is operating, so that the chemical solution flows inside the chemical solution tank 6. It circulates. The pump 11 is also operating at the same time, and the chemical liquid is constantly circulated in the chemical liquid tank 6.

Then, when the semiconductor wafer 1 is mounted on the stage and the stage is rotated, before the semiconductor wafer 1 is cleaned, the concentration calculator 30 in the cleaning control means 29 is based on the signal output from the concentration monitor 13. The chemical concentration value is calculated and the calculation result is output to the central processing unit 31.

Next, the central processing unit 31 automatically calculates the optimum cleaning time for the chemical concentration based on the calculation result, outputs a control signal to the valve control unit 22a and opens the valve 18a, Similarly, by outputting a control signal to the valve controller 21a to close the valve 17a, the nozzle 15
Cleaning is performed by spraying a chemical solution onto the semiconductor wafer 1 from a.

At this time, the open / close valve provided in the drain 3a is opened and the chemical liquid is collected in the chemical liquid tank 6. After that, when the cleaning is completed, a rinse with pure water is performed, and the semiconductor wafer 1 is dried in the drying process.

The pure water in the rinse is treated as a waste liquid by opening the opening / closing valve of the drain 3b.

As a result, in the second embodiment, even if the concentration of the chemical liquid in the chemical liquid tank 6 is changed by the cleaning control means 29,
The optimum cleaning time for the concentration of the chemical solution can be automatically calculated to perform the cleaning, and the cleaning effect can be made constant.

Further, since the cleaning effect can be kept uniform regardless of the concentration fluctuation of the chemical liquid, it is not necessary to discard the chemical liquid due to the concentration change of the chemical liquid in the chemical liquid tank 6, and the cost of the chemical liquid can be greatly reduced. You can also

The invention made by the inventor has been specifically described based on the embodiment. However, the invention is not limited to the embodiment and can be variously modified without departing from the gist of the invention. Needless to say.

For example, in the first and second embodiments,
Although the semiconductor wafer cleaning device has been described, a semiconductor manufacturing device other than the cleaning device may be used, and a good semiconductor device can be obtained by using the semiconductor manufacturing device such as a wet etching device for etching a semiconductor wafer in which stabilization of chemical concentration is important. Can be manufactured.

[0072]

The effects obtained by the typical ones of the inventions disclosed in this application will be briefly described as follows.
It is as follows.

(1) According to the present invention, the chemical concentration in the chemical tank is monitored, and the first liquid for increasing the chemical concentration or the second liquid for decreasing the chemical concentration is supplied to automatically adjust the chemical concentration. Since it is constantly kept constant, it is possible to prevent fluctuations in the concentration of the chemical liquid and deterioration of the chemical liquid.

(2) Further, according to the present invention, even if the chemical concentration in the liquid tank fluctuates, the object to be treated can be automatically processed in the optimum treatment time for the changed chemical concentration.

(3) Further, in the present invention, due to the above (1) and (2), it is not necessary to exchange the chemical liquid, the cost can be largely reduced, and the quality of the semiconductor device can be improved.

[Brief description of drawings]

FIG. 1 is a configuration explanatory diagram of a cleaning device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a cleaning solution concentration controller according to the first embodiment of the present invention.

FIG. 3 is a structural explanatory view of a cleaning device according to a second embodiment of the present invention.

FIG. 4 is a block diagram of cleaning control means according to a second embodiment of the present invention.

[Explanation of symbols]

 1 Semiconductor Wafer (Processing Object) 2 Cleaning Device (Semiconductor Manufacturing Device) 3 Cup 3a Drain 3b Drain 4 Piping 5 Piping 6 Chemical Solution Tank 7 Heater (Heating Means) 8 Piping 8a Valve (First Flow Limiting Means) 9 Piping 9a Valve (second flow limiting means) 10 Piping 11 Pump 12 Filter 13 Concentration monitor (detecting means) 14 Pump 15 Piping 15a Nozzle 16 Filter 17 Valve 17a Valve (flow limiting means) 18 Valve 18a Valve (flow limiting means) 19 Cleaning Chemical concentration control unit 20 Concentration calculation unit (calculation unit) 21 Valve control unit (flow rate limiting unit) 21a Valve control unit (flow rate limiting unit) 22 Valve control unit (flow rate limiting unit) 22a Valve control unit (flow rate control unit) 23 Input Section 24 storage section 25 display control section 26 display 27 heater control section ( Thermal control means) 28 central processing unit (concentration control means) 29 wash control section 30 concentration calculating unit (concentration calculating means) 31 central processing unit (processing controller) NK1 concentration detecting section NC1 density control means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Sato 2326 Imai, Ome City, Tokyo, Hitachi Device Development Center (72) Inventor Motoko Ono 2326 Imai, Ome City, Tokyo Hitachi Device Development Center (72) Inventor Hiroko Akimori 2326 Imai, Ome City, Tokyo Metropolitan area, Hitachi Device Development Center (72) Inventor Tomoko Jimbo 2326 Imai, Ome city, Tokyo Metropolitan area Device Development Center (72) Invention Yukino Imamura 2326 Imai, Ome-shi, Tokyo Inside Hitachi Device Development Center

Claims (4)

[Claims] 1. A semiconductor manufacturing apparatus for processing an object to be processed using a chemical solution, comprising concentration detecting means for detecting the chemical solution concentration in a chemical solution tank storing the chemical solution, and the concentration detecting means. A semiconductor manufacturing apparatus, comprising: concentration control means for determining whether or not the chemical concentration is a prescribed chemical concentration and controlling the chemical concentration in the chemical tank to be constant. 2. The semiconductor manufacturing apparatus according to claim 1, wherein the concentration detecting means detects a chemical concentration in the chemical bath and a chemical concentration value based on a signal output from the detecting means. First concentration limiting means for limiting the flow rate of the first liquid for increasing the concentration of the chemical liquid supplied to the chemical liquid tank, and the chemical liquid supplied to the chemical liquid tank. A second flow rate limiting unit that limits the flow rate of the second liquid that reduces the concentration, and a concentration that outputs a predetermined control signal by comparing the chemical concentration value output from the arithmetic unit with a prescribed chemical concentration value. Control means,
A semiconductor manufacturing apparatus comprising: a flow rate control unit that controls the first flow rate limiting unit and the second flow rate limiting unit based on a control signal output from the concentration control unit. 3. The semiconductor manufacturing apparatus according to claim 2, wherein the concentration control means has a heating means for heating the chemical liquid in the chemical liquid tank, and the heating means of the heating means is based on a control signal output from the concentration control means. A semiconductor manufacturing apparatus, comprising: heating control means for controlling. 4. A semiconductor manufacturing apparatus for processing an object to be processed using a chemical liquid, comprising: a concentration detection means for detecting the chemical concentration in a chemical liquid tank for storing the chemical liquid; and a signal output from the concentration detection means. Concentration calculation means for calculating the concentration of the chemical solution based on the above, processing control means for automatically setting the processing time of the object to be processed based on the calculation result output from the concentration calculation means, and injection to the object to be processed A semiconductor manufacturing apparatus comprising: a flow rate limiting means for limiting a flow rate of a chemical; and a flow rate controlling means for controlling the flow rate limiting means based on a control signal output from the processing control device.