JPH11138439A - Abrasive liquid supplying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an abrasive liquid supplying device capable of stably supplying abrasive liquid having the constant concentration by preventing precipitation to a piping through which abrasive liquid is to be allowed to flow and to a wall surface of a container for temporarily storing abrasive liquid. SOLUTION: An abrasive liquid supplying device for supplying abrasive liquid to polishing devices 22 is provided with at least two supplying sources for undiluted solution and diluent, a mixing part 18 for mixing undiluted solution and diluent to be supplied from the supplying sources, and extracting paths 24 for supplying abrasive liquid mixed in the mixing part 18 to the polishing devices 22, and the mixing part 18 is so constituted as to be airtight in relation to the external space. As undiluted solution of abrasive liquid, acid, alkaline and neutral liquid containing grains having the specified grain size, such as silica gel, are used according to the polishing target, and pure water having no impurity is used as diluent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing liquid supply apparatus for use in, for example, a polishing apparatus for a semiconductor substrate, and more particularly to a polishing liquid supply apparatus capable of stably supplying a polishing liquid having a constant concentration. It is.

[0002]

2. Description of the Related Art In recent years, as the degree of integration of semiconductor devices has increased, circuit wiring has become finer, and the distance between wirings has become smaller. Accordingly, when a circuit is formed by optical lithography or the like, the depth of focus becomes shallow, so that a higher flatness of the imaging surface of the stepper is required.

As means for flattening the surface of a semiconductor wafer, a polishing tool (for example, a polishing table having a polishing cloth), a gripping member for gripping a material to be polished against the polishing table and pressing the polished surface are provided. There is known a polishing apparatus which performs polishing by relatively sliding a tool and a polishing surface while supplying a polishing liquid between these contact surfaces. Such an apparatus not only performs mechanical polishing using a polishing liquid as a polishing liquid, but also performs polishing involving a chemical action using an alkaline or acidic polishing liquid as the case may be.

In such a polishing apparatus, factors that govern the removal rate (polishing rate) of the surface layer of the workpiece are as follows.
It is known that the concentration of the polishing liquid (abrasive liquid) (the supply amount of the polishing liquid), as well as the pressing pressure of the wafer against the polishing tool (polishing cloth), the sliding speed, and the like, also affect the wafer. Controlling the polishing rate to a constant value is important not only for improving the flatness but also for detecting the end point for confirming the end point of polishing.

As an apparatus for supplying a polishing liquid having a constant concentration, for example, an abrasive liquid supply apparatus described in Japanese Patent Application Laid-Open No. 7-52045 is known. This is a stock solution tank,
The polishing apparatus includes first and second adjustment tanks for adjusting the concentration of the polishing liquid through two stages, and a circulation tank for supplying or circulating the adjusted polishing liquid to the polishing apparatus.

[0006] These undiluted liquids and abrasive liquids do not normally react and deteriorate when they come into contact with air. Therefore, although the above-mentioned tanks are sealed by a lid, the atmosphere in the tanks is kept from outside air. The structure was not designed to positively prevent air flow so as to shut off.

[0007]

However, in the above-mentioned prior art, the atmosphere in each tank escapes to the outside and becomes dry, while the level of the abrasive liquid and the stock solution in the tank fluctuates. . As a result, the fluid adhering near the high level of the tank is vaporized, and solutes are deposited. And, as the liquid level repeats up and down, this precipitate grows, dries and falls, causing clogging of the liquid outlet, etc.
Not only does it hinder stable operation, it also causes instability of the liquid concentration.

Further, usually, the use of for containing polishing liquid in an amount sufficient to the amount used in the polishing of one day, also the tank for adjusting the concentration of 1 m ³ to 2 m ³ approximately large ones in the tank There were many.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to prevent the deposition on a wall of a piping for temporarily passing a polishing liquid or the like and a container for temporarily storing the polishing liquid, thereby stably supplying a polishing liquid having a constant concentration. It is an object of the present invention to provide a polishing liquid supply device that can perform the polishing.

[0010]

The invention according to claim 1 is a polishing liquid supply apparatus for supplying a polishing liquid to a polishing apparatus,
At least two sources of the undiluted solution and the diluent, a mixing unit for mixing the undiluted solution and the diluent supplied from these sources, and a withdrawal path for supplying the polishing liquid mixed in the mixing unit to the polishing apparatus. Wherein the mixing unit is configured to be airtight with respect to an external space.

[0011] Thus, since the mixing section is airtight, the atmosphere in the mixing section is prevented from being affected by the outside air, and drying and precipitation of the abrasive liquid on the wall surface of the mixing section are prevented. The reaction of the abrasive liquid and the mixture of foreign matter are also prevented. The mixing section is configured as a joining pipe or an airtight container having an arbitrary shape. If configured as a container having a certain capacity, it acts as a buffer unit (buffer) for absorbing fluctuations in the amount of use on the downstream side.

The mixing section may constitute a part of a circulation path for circulating the abrasive liquid. Such a circulation path is arranged so as to pass in the vicinity of one or a plurality of polishing apparatuses, and the supply of the polishing liquid to each polishing apparatus is performed through a drawing pipe branched from the circulation path in the vicinity of the polishing apparatus. . By doing so, the stagnation of the polishing liquid in the path from the mixing section to the polishing apparatus is prevented, and clogging due to concentration change and precipitation of the polishing liquid is prevented. By providing a level sensor for detecting the remaining amount of the abrasive liquid in the mixing section in the mixing section, it is possible to control the liquid level in the mixing section to always be maintained within a certain level range.

The invention according to claim 2 is characterized in that the mixing section is provided with a pressure adjusting mechanism for adjusting the internal pressure while maintaining the airtight state of the mixing section. 3. The polishing liquid supply device according to item 1. As such a mechanism, for example, an airbag that expands and contracts according to the level of the liquid level can be used. In this case, it is preferable to provide a temperature adjusting means in the mixing section or the airbag so as to prevent condensation of moisture in the airbag.

According to a third aspect of the present invention, there is provided a polishing liquid supply apparatus for supplying a polishing liquid to a polishing apparatus, wherein a circulation path for circulating the polishing liquid, and the polishing liquid is supplied from the circulation path to the polishing apparatus. A polishing liquid supply apparatus, wherein the circulation path and the discharge path are airtightly configured. The final end of the extraction path is a nozzle in the polishing apparatus, which opens when used, but closes the on-off valve when not used so that the inside of the pipe is shut off from the outside.

According to a fourth aspect of the present invention, there is further provided a stock solution tank, a diluting solution tank, and a mixing section for mixing the stock solution and the diluting solution, and the entire fluid path including these tanks is airtight. The abrasive liquid supply device according to claim 3, wherein

According to a fifth aspect of the present invention, there is provided a cleaning mechanism for cleaning an undiluted solution supply path for supplying the undiluted solution to the mixing section, wherein the mixing section supplies an additive to the polishing liquid. 5. The polishing liquid supply device according to claim 1, further comprising an additive supply pipe.

Based on this signal, the supply of the stock solution and the diluent is controlled so that the remaining amount of the polishing liquid in the mixing section falls within a predetermined range, or an alarm is issued if the remaining amount decreases. be able to. For the cleaning mechanism, for example, a configuration is used in which the diluting liquid is caused to flow through the undiluted liquid supply path and guided to the drain by switching a valve. The stock solution supply line and the diluent solution supply line may be alternately switched so that the line is washed alternately.

According to a sixth aspect of the present invention, a flow rate adjusting means for adjusting the flow rate of the stock solution and / or the diluent to the mixing section, and controlling the flow rate adjusting means to adjust the concentration of the abrasive liquid in the mixing section. The polishing liquid supply device according to claim 1, further comprising a control device for keeping the polishing liquid constant.

According to a seventh aspect of the present invention, a flow path for supplying a diluent is further connected to the flow rate adjusting means in the raw liquid supply path, and a flow path for further supplying the raw liquid to the flow rate control means in the diluent liquid supply path. And a means for alternately switching between a stock solution and a diluting solution.
3. The polishing liquid supply device according to item 1.

The invention according to claim 8 is a polishing liquid supply apparatus for supplying a polishing liquid to a polishing apparatus, comprising a mixing section for adjusting the concentration and / or components of the polishing liquid used in the polishing apparatus. The abrasive fluid supply device is characterized in that flow rate control means for adjusting the flow rate by adjusting the secondary pressure is used for supplying the fluid to the mixing section.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. This polishing liquid supply device includes a raw liquid tank 10 containing a raw polishing liquid, a diluting liquid source 12 for diluting the polishing liquid to a predetermined concentration, and pipes 14 and 16 from these sources. A mixing unit 18 that joins the supplied raw materials to form a polishing liquid having a predetermined concentration, a circulation path 20 that circulates the polishing liquid, and a polishing apparatus 22
And a withdrawal pipe 24 for supplying the abrasive liquid toward the nozzle.

As the stock solution of the polishing solution, for example, an acid, alkali or neutral solution containing particles of a predetermined particle size such as silica gel is used according to the object to be polished. No pure water is used. In this example, the stock solution is stored in the stock solution tank 10 and the stock solution supply line 14
Should be switched when one becomes empty.
A system is provided. The stock solution line 14 and the diluent solution line 16 are provided with an on-off valve 26, a constant flow valve 28, and an orifice 29, respectively.

As shown in FIG. 3, the constant flow valve 28 includes an upper casing 66, a lower casing 68, and a lower holding plate 70.
The valve device 72 is housed in a casing made of. That is, an air pressure chamber 76 having a pressure introduction passage 74 communicating with a pilot air source (not shown) is formed in the upper casing 66, and a fluid introduction passage 78, a primary valve chamber 80, and a secondary valve chamber 82 are formed in the lower casing 68. , Fluid outlet 8
4 is formed, and a diaphragm 86 is interposed between the upper casing 66 and the lower casing 68 to define an air pressure chamber 76 and a secondary valve chamber 82.

A valve seat 88 is formed between the primary valve chamber 80 and the secondary valve chamber 82, and a valve body 90 is inserted from below into the valve seat 88. The valve body 90 is attached to a diaphragm 86 by a pressing plate 92. It is attached to a valve stem 96 fixed by bolts 94 and can be moved up and down. O-rings 98 for sealing are respectively arranged at predetermined positions on the joint surfaces of the members constituting the constant flow valve 28.

With the constant flow valve 28 having such a configuration, the amounts of the stock solution and the diluent supplied to the buffer tube 18 can be strictly controlled. That is, a flow rate instruction signal corresponding to a required flow rate is output from the control device (not shown) to the electropneumatic converter of each pilot air source. The electropneumatic converter sends the corresponding air pressure as a pilot air pressure to the air pressure chamber 76 of the constant flow valve 28 based on the flow instruction signal. Accordingly, in the constant flow valve 28, the abrasive fluid flowing from the fluid inlet 78 of the constant flow valve 28 flows into the fluid pressure chamber 82 through the opening formed by the valve device 72, the valve body 90 and the valve seat 88. The pressure in the fluid pressure chamber 82 is uniquely determined by the flow rate of the abrasive fluid flowing through the orifice 29. Therefore, by controlling the pressure of the fluid pressure chamber 82 to a desired pressure, the flow rate of the polishing liquid can be controlled to a desired amount.

At this time, the flow rate of the abrasive fluid output from the fluid outlet 84 is kept constant by controlling the pressure of the fluid pressure chamber 82 as follows. The pilot pressure of the air pressure chamber 76 and the abrasive fluid pressure of the fluid pressure chamber 82 are balanced via the diaphragm 86 and flow out from the fluid outlet 84. At this time, when the pressure of the fluid pressure chamber 82 increases, the valve rod 96 and the valve body 90 are pushed upward, and the space formed by the valve seat 88 and the valve body 90 serving as a fluid flow path is fitted, and the flow path Since the resistance increases, the abrasive fluid pressure in the fluid pressure chamber 82 instantaneously returns to a predetermined pressure (a pressure balanced with the pilot air pressure of the air pressure 76). When the pressure in the fluid pressure chamber 82 becomes low, the action is reversed, and the pressure returns to the predetermined pressure. As a result, the fluctuation width and cycle of the pilot air pressure become shorter, and a predetermined flow rate of the abrasive fluid determined by the pilot air pressure and the pipe resistance on the downstream side is stably supplied to the mixing unit 18.

However, the orifice 29 provided downstream of the constant flow valve 28 is provided when it is desired to obtain a flow rate exceeding the range of the polishing liquid flow rate obtained by changing the pilot air pressure. By providing the orifice 29 corresponding to the desired flow rate, the ratio between the stock solution and the diluent can be freely changed. When the pipes 14 and 16 serve as orifices, the orifices 29 need not be provided. By using such a constant flow valve 28 for the stock solution line 14 and the diluent solution line 16, it is possible to precisely control the supply amounts of the raw material of the polishing solution and the diluting solution, and to produce the desired concentration of the polishing solution. Can be.

In this example, the buffer tube 18 serving as a mixing section is connected to a circulation path 2 for supplying an abrasive to a plurality of polishing apparatuses.
It is installed in the middle of 0. This buffer tube 18
As shown in FIG. 2 which is a more substantial explanatory view, the pipe is vertically arranged as a cylindrical container 30 having a larger diameter than the circulation pipe 21 forming the circulation path 20, and a discharge port 32 is provided at the bottom.
, And the upper portion is covered with a lid 36 joined via an O-ring 34. A return pipe 38 to which the return side of the circulation pipe 21 is connected is inserted into the lid 36 so as to extend to near the bottom of the container 30.
4 and (not shown, but similar to pipe 14) pipe 16
Are inserted halfway through the container 30, respectively. Further, it is desirable that the volume of the buffer tube 18 be configured so as not to exceed the amount of the polishing liquid for 24 hours used in the polishing apparatus. This is because the polishing liquid may deteriorate due to long-term storage.

The vessel 30 is provided with level detectors 40a, 40b, and 40c for detecting the level of the liquid level. The level detectors detect, for example, an upper limit, a lower limit, and a lower limit, and transmit the signals to a control device (not shown). Output. In the present embodiment, a capacitance type level sensor is used as the level sensor. On the basis of this signal, the control device outputs a signal to the on-off valve 26 and the pump 25 of the line for the undiluted solution and the diluent, and supplies the undiluted solution and the diluent when the liquid level is at the lower limit, and when the level is at the upper limit. Control so that supply is stopped. If the liquid level reaches the lowermost limit, an alarm, a stop signal for the polishing apparatus 22, or the like is issued.

The lid 36 is further provided with an air flow pipe 44 for communicating the air in the container 30 with an airbag 42 made of a stretchable material. The airbag 42 keeps the space in the container 30 airtight with respect to the outside air and suppresses internal pressure fluctuations due to fluctuations in the liquid level inside. The airbag 42 is flexible and durable, such as Teflon (trade name). It is formed of a material having a volume corresponding to the level fluctuation. Note that the temperature of the airbag 42 is
If the temperature is lower than 0, moisture condenses inside the airbag 42. Therefore, when there is a possibility that a temperature difference may occur, the container 30 may be cooled by a jacket or the like.
It is preferable to provide a temperature adjusting means in one or both of the airbag and the airbag, and to provide a temperature sensor for controlling the temperature adjusting means. Further, since each of the pipes 14, 16, 21 and the container 30 are connected to each other by a joint via a seal material such as a seal tape, the pipe system is also kept airtight.

The circulation pipe 21 goes from the discharge port 32 at the lower end of the buffer tube 18 to the vicinity of one or a plurality of polishing apparatuses 22 to which the abrasive liquid is to be supplied, returns to the buffer tube 18, and is connected to the return pipe 38. It is configured. The circulation pipe 21 is provided with a circulation pump 46 for circulating the abrasive fluid, a back pressure valve 48 for keeping the pressure in the circulation pipe at a certain pressure or higher, a pressure sensor 50, and the like. A line mixer 47 may be attached to the discharge side pipe of the circulation pump 46. The output of the pressure sensor 50 is input to a control device and monitored. The control device may control the operation of the circulation pump 46 according to the detected value to keep the pressure in the circulation pipe 21 constant. Normally, the circulation pump 46 is kept at a constant operation, and the pressure in the piping is kept constant by the back pressure valve 48. The circulation pipe 21 has a withdrawal pipe 24 branching from a position near each polishing apparatus 22 and extending toward the polishing apparatus. The extraction pipe 24 is connected to the polishing apparatus 22 through an on-off valve 52 and a flow rate adjustable pump 54. Liquid nozzle 56 opening at a predetermined position
It is connected to the.

As described above, by constantly circulating the polishing liquid in the pipe for guiding the polishing liquid to the vicinity of the polishing apparatus 22, it is possible to prevent the liquid concentration from changing due to stagnation in the pipe and to prevent clogging due to solid deposition. Can be. Further, since the length of the pipe can be increased, the polishing liquid can be stably supplied from one polishing liquid supply source (mixing unit) 18 to the plurality of polishing apparatuses 22, and the apparatus cost can be reduced. Since each polishing device 22 has a stoppage time, the extraction pipe
In this case, stagnation occurs. Before the polishing operation starts, however, the influence of the stagnation can be eliminated by extracting the abrasive liquid and flowing it in such a small amount as to replace the abrasive liquid in the tube in order to prevent the stagnation.

In this polishing liquid supply device, the mixing section 18
Is hermetically closed and airtight from the outside. In addition, the extraction pipe 24 also has its nozzle 56
Except for the opening, there is a closed system that is isolated from the outside. Therefore, the atmosphere in the piping system including the buffer tube 18 is constant, is maintained at a state relatively close to the saturated vapor pressure, and the grinding liquid is prevented from sticking to the inner surface due to drying.
In this example, a stock solution supply line 14 including a stock solution tank 10 and a diluent tank 12 for storing a diluent such as pure water
The diluent supply line 16 containing is also hermetically sealed to thoroughly prevent sticking by preventing drying and to prevent the influence of air oxidation.

When the amount of the polishing liquid in the mixing section 18 decreases,
Since the stock solution and the diluting solution are added at any time to replenish the polishing solution with an appropriate concentration and the polishing solution is circulated in the closed system by the circulation pipe 20, the size of the mixing section 18 itself for concentration adjustment is very large. Small enough. For example, when the polishing liquid is supplied from one polishing liquid supply device to three polishing devices, the mixing unit 18 has a volume of about 5 l. Further, even when supplying to about 30 polishing apparatuses, a volume of about 40 l is sufficient.

The operation of the polishing liquid supply device configured as described above will be described. The control device controls the circulation pump 46 so that the pressure on the downstream side thereof is equal to or higher than a predetermined value, whereby the circulation flow of the polishing liquid in the circulation path 20 is always formed. When each polishing device 22 is operated, a part of the polishing liquid is discharged from the extraction pipe 24 to the nozzle 56 of the polishing device 22.
More outflow. When the amount of the polishing liquid in the buffer tube 18 falls below the lower limit, the control device opens the on-off valve 26 and activates the pump 25 in response to a signal from the level sensor 40b. Further, the constant flow valve 28 controls the flow rates of the undiluted solution and the diluent by outputting a flow rate instruction signal corresponding to a required flow rate from a control device (not shown). As a result, the undiluted solution and the diluent have a predetermined ratio, and flow into the buffer tube 18 until the liquid level reaches the upper limit. Thus, the stock solution and the diluent are mixed here. In the case of the abrasive liquid which is hard to be sufficiently mixed only in the mixing section 18, the abrasive liquid is further sufficiently mixed by the line mixer 47 provided in a part of the circulation pipe 21.

As described above, the liquid level in the buffer tube 18 repeatedly rises and falls, but the airbag 42 expands and contracts accordingly.
The pressure within zero is maintained substantially constant and does not interfere with the operation of the circulation pump 46. Further, since the container 30 is in a closed state, the vapor does not escape to the outside, the internal vapor pressure is maintained at a value close to saturation, and the polishing liquid on the inner surface of the container 30 is prevented from drying. Accordingly, there is no precipitation of the solute of the polishing liquid on the wall surface, and the operation instability due to the clogging of the pipe and the adverse effect on the polishing operation due to the change in the polishing liquid concentration are prevented.

In order to prevent a negative pressure from being generated due to a level change in the stock solution tank 10 or the diluting solution tank 12, an air bag may be provided in these as well as the buffer tube 18. As shown in FIG. 4, an elastic container (bag) 100 for storing a Teflon slurry stock solution may be provided inside the stock solution tank 10 or the diluent solution tank 12. In this case, the outer wall of the tank 10 and the inner container 100
By applying pressure from the air source 102 during this time, the slurry stock solution can be sent to the buffer tube 18 without coming into contact with the gas phase.

In the above embodiment, a washing mechanism for washing the stock solution supply path 14 for feeding the stock solution to the mixing section 18 may be provided. FIG. 5 shows such an embodiment, wherein the cleaning mechanism comprises valves 26a, 26b, 26c,
The diluent and the stock solution are supplied to the stock solution supply path 14
a, 14b to supply the undiluted solution supply paths 14a, 14
This prevents clogging at b.

In this embodiment, the valves 26, 26a are opened according to the signal of the level sensor 40b in the buffer tube, and a constant flow rate of the diluent is supplied from the diluent line 16 and the diluent line 14a. The valve 26d is opened from 14b to supply a constant flow of the stock solution. By the upper limit signal of the level sensor 40a in the buffer tube,
The valves 26, 26a, 26d are closed simultaneously. Next, when the polishing liquid is consumed by the polishing apparatus 22 and reaches the liquid level of the level sensor 40b, the valves 26 and 26c are opened and the diluting liquid line 16 and the undiluted liquid line 14 are maintained at a constant flow rate as described above.
The diluent is supplied from b, and the diluent is supplied from the diluent supply path 14a. Thus, the concentration of the abrasive liquid in the mixing section 18 is adjusted, and at the same time, the raw liquid supply paths 14a and 14b are cleaned. Here, although the diluent line 16 is used only for diluent supply, the diluent supply pipe is connected to the diluent supply path 14a,
By connecting them in the same manner as 14b, they may be used as a stock solution supply path.

In the above-described embodiment, the undiluted solution and the diluent are mixed in the mixing section 18.
Further, in order to modify the polishing liquid, a path for supplying one or more kinds of additives such as an oxidizing agent and a surfactant to the mixing section 18 is separately provided, and the mixing section 18 for the above-mentioned undiluted solution or diluting liquid is provided.
Similarly to the configuration of the supply to the mixing unit 18, the liquid may be supplied to the mixing unit 18 and three or more liquids may be mixed in the mixing unit 18. Also in the case of adding the additive, the additive and the diluent may be alternately supplied from one supply pipe in the same manner as in the configuration of the supply of the stock solution or the diluent to the mixing unit 18 described above.

In the above embodiment, the polishing liquid for polishing the wafer is mixed. However, after polishing is further completed by the polishing apparatus, a surfactant and a dispersant are used instead of the polishing liquid. Alternatively, the wafer may be cleaned by supplying a liquid obtained by mixing one or more cleaning liquids such as an acidic or alkaline etching agent and a diluent in the mixing section 18 onto the polishing pad. Also, instead of a polishing device,
Similarly, in a processing apparatus such as a cleaning apparatus, a cleaning agent or the like that needs to be mixed may be supplied to a processing unit of a substrate to be processed in the processing apparatus.

[0042]

As described above, according to the present invention, since the mixing section is air-tight, the atmosphere in the mixing section is suppressed from being affected by the outside air, and the piping or the like for flowing the abrasive fluid or the like is prevented. Prevention of precipitation on the wall surface of the container for temporarily storing the polishing liquid can stably supply a constant concentration of the polishing liquid, and also prevent the reaction between the outside air and the polishing liquid and the entry of foreign matter. Therefore, a favorable polishing operation in a polishing apparatus for a semiconductor substrate or the like can be promoted.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an overall configuration of a polishing liquid supply device according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a configuration of a buffer tube of the polishing liquid supply device of FIG.

FIG. 3 is a sectional view showing a configuration of a constant flow valve of the polishing liquid supply device of FIG. 1;

FIG. 4 is a sectional view showing another embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a configuration of still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Undiluted solution tank 12 Diluent tank 14 Undiluted solution supply path 18 Mixing part 20 Circulation path 22 Polishing device 24 Extraction path 28 Constant flow valves 40a, 40b, 40c Level sensor 42 Airbag (pressure adjustment mechanism)

Claims (8)

[Claims] 1. A polishing liquid supply device for supplying a polishing liquid to a polishing apparatus, comprising: at least two supply sources of a raw liquid and a diluting liquid; and a mixing section for mixing the raw liquid and the diluting liquid supplied from these supply sources. And a withdrawal path for supplying the polishing liquid mixed in the mixing section to a polishing apparatus, wherein the mixing section is airtightly configured to an external space. 2. The polishing liquid supply device according to claim 1, wherein the mixing section is provided with a pressure adjusting mechanism for adjusting an internal pressure while maintaining an airtight state of the mixing section. . 3. A polishing liquid supply apparatus for supplying a polishing liquid to a polishing apparatus, comprising: a circulation path for circulating the polishing liquid; and a withdrawal path for supplying the polishing liquid from the circulation path to the polishing apparatus. The polishing liquid supply device, wherein the circulation path and the extraction path are configured to be airtight. 4. The method according to claim 3, further comprising a stock solution tank, a diluent tank, and a mixing unit for mixing the stock solution and the diluent, wherein all the fluid paths including the tanks are airtight. Abrasive fluid supply device. 5. A cleaning mechanism for cleaning an undiluted liquid supply path for supplying the undiluted liquid to the mixing section, wherein the mixing section is provided with an additive supply pipe for supplying an additive to the polishing liquid. 5. The method according to claim 1, wherein
The polishing liquid supply device according to any one of the above. 6. A flow rate adjusting means for adjusting a flow rate of a stock solution and / or a diluting liquid to the mixing section, and a control device for controlling the flow rate adjusting means to keep a concentration of the polishing liquid in the mixing section constant. The polishing liquid supply device according to any one of claims 1, 2, 4, and 5, further comprising: 7. A flow path for supplying a diluting liquid is further connected to the flow rate adjusting means in the raw liquid supply path, and a flow path for further supplying a raw liquid is connected to the flow rate control means in the diluting liquid supply path. 7. The polishing liquid supply device according to claim 6, further comprising means for switching a diluting liquid alternately. 8. A polishing liquid supply apparatus for supplying a polishing liquid to a polishing apparatus, comprising a mixing section for adjusting the concentration and / or composition of the polishing liquid used in the polishing apparatus, and supplying a fluid to the mixing section. Wherein a flow rate control means for adjusting a flow rate by adjusting a secondary side pressure is used.