JPH0957609A - Abrasive fluid supplying device for mechanochemical polishing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an abrasive fluid supplying device for mechanochemical polishing, capable of supplying the abrasive fluid whose properties are always constant to polishing device without change of concentration caused by fluctuation of the mixing ratio of abrasive undiluted fluid to solvent and without change of concentration caused by precipitation of abrasive fine grains. SOLUTION: Only one set of a undiluted liquid measuring tank 4 for measuring abrasive undiluted fluid from a undiluted liquid tank 1 and a solvent measuring tank 6 for measuring solvent such as water is provided, the fluid are mixed by measuring them under the always same condition, so as to held the mixing ratio of the abrasive undiluted fluid to the solvent constant. The abrasive undiluted fluid or abrasive fluid in the undiluted liquid tank 1, the undiluted liquid measuring tank 4, a mixing tank 9 and a supplying tank 11 are agitated by being always circulated through supplying pipes 16, 28, 45, 50 attached to respective tanks and circulating pipes 17, 29, 46, 51 by pumps 18, 31, 47, 52, and abrasive fine grains are prevented from being precipitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abrasive liquid for supplying an abrasive liquid to the polishing device when chemical mechanical polishing (mechanochemical polishing) is performed on the surface of a semiconductor wafer, a ceramic wafer or the like by the polishing device. The present invention relates to a supply device.

[0002]

2. Description of the Related Art In recent years, with the development of semiconductor device manufacturing technology, many devices having a laminated structure have been manufactured. During the manufacturing process of a semiconductor device having such a laminated structure, there is a process of polishing the surface of a semiconductor wafer having an upper surface provided with wiring and an insulating film covering the wiring, and by this step, the flattening of the wafer surface is performed. And smoothing and uniformizing the film thickness of the insulating coating.

Conventionally, the surface of such a semiconductor wafer is flattened and smoothed by chemical mechanical polishing. In this chemical mechanical polishing, a semiconductor wafer is brought into contact with a rotary platen to which a polishing pad is attached, and the surface of the wafer is polished while supplying an abrasive liquid from a supply device.

In such chemical mechanical polishing of a semiconductor wafer, it is difficult to directly measure and control the film thickness of the insulating film. Therefore, a method of controlling the film thickness by the polishing time is generally used. However, since the polishing rate greatly changes due to the change in the properties of the polishing agent liquid, the film thickness cannot always be kept constant even if the processing time is kept constant, and the quality tends to vary.

On the other hand, some of the polishing agent liquids used for the chemical mechanical polishing have fine particles for polishing such as colloidal silica, potassium hydroxide and alumina suspended in pure water or other solvent. However, these are properly used according to the type of the work piece, but there is a problem that the property tends to change with the change in concentration. The main causes of such a concentration change are the precipitation of fine particles for polishing, the deviation of the mixing ratio in the process of mixing the stock solution of the abrasive and the solvent, and the like.
In some cases, the properties of the polishing agent liquid may change depending on the temperature change. Furthermore, when the supply device stands by for preparation and supply of the next abrasive liquid, the abrasive liquid solidifies by drying at the position of the pipes and pumps in the standby state and adheres to these pipes and pumps. There were also many problems of getting stuck.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to prevent a change in property caused by a change in concentration of an abrasive liquid or a temperature change and to always supply an abrasive liquid having a constant property to a polishing apparatus. To provide an abrasive liquid supply device for chemical mechanical polishing. Another object of the present invention is to provide an abrasive liquid supply device for chemical mechanical polishing that can simultaneously prevent clogging of pipes and pumps due to drying of the abrasive liquid.

[0007]

In order to solve the above-mentioned problems, a polishing agent liquid supply apparatus of the present invention is a stock solution tank for containing a slurry-like stock solution of a polishing material; and measuring a stock solution of a polishing material from the stock solution tank. A stocking unit equipped with only one set of a stock solution measuring tank and a solvent measuring tank for measuring a solvent from a solvent source; a polishing agent stock solution and a solvent measured in each of the above measuring tanks are mixed to polish a required concentration. A mixing tank for obtaining a material liquid; a polishing material liquid supply tank for receiving the polishing material liquid prepared in the mixing tank and supplying it to the polishing apparatus; provided in the stock solution tank between the stock solution tank and the stock solution measuring tank A supply pipe for supplying an undiluted solution of abrasive material to a stock solution measuring tank;
And a pump for pumping the stock solution of abrasive material, and when the stock solution of abrasive material is not supplied to the stock solution metering tank, a stock solution transfer pipe for metering that circulates the stock solution of abrasive material in the stock solution tank through the supply pipe and the reflux pipe. A path; a supply pipe provided between the stock solution measuring tank and the mixing tank, for supplying the polishing agent stock solution in the stock solution measuring tank to the mixing tank, and a tip of the supply pipe branched from a part of the supply pipe. Equipped with a reflux pipe and a pump for pumping the stock solution of the polishing material, and when the stock solution of the polishing material is not supplied to the mixing tank, the stock solution of the polishing material in the stock solution measuring tank is supplied to the supply pipe and the reflux pipe. A stock solution transfer pipeline for mixing, which is circulated through; a solvent transfer pipeline for mixing, which is provided between the solvent measurement tank and the mixing tank and which supplies the solvent in the solvent measurement tank to the mixing tank; A supply pipe that is provided between the mixing tank and the polishing tank to supply the polishing agent liquid in the mixing tank to the supply tank; And a pump for pumping the liquid, and when the abrasive liquid is not supplied to the supply tank, the abrasive liquid transfer pipeline for supply that circulates the abrasive liquid in the mixing tank through the supply pipe and the reflux pipe. A supply pipe provided between the supply tank and the polishing device for supplying the polishing material liquid in the supply tank to the polishing device, a reflux pipe for guiding the supply pipe to the supply tank, and pressure-feeding the polishing liquid. With a pump for
It has a loading abrasive liquid transfer line for constantly circulating the abrasive liquid in the supply tank through the supply pipe and the reflux pipe.

The abrasive liquid supply device having the above-described structure agitates the abrasive stock solution or the abrasive liquid in each tank by circulating it through the supply pipe and the reflux pipe of the transfer pipes connected to those tanks. Therefore, it is possible to reliably prevent the concentration change due to the precipitation of the polishing fine particles and the clogging of the piping and the pump due to the drying of the abrasive liquid.

Further, since a set of a stock solution measuring tank and a solvent measuring tank is used to measure an abrasive stock solution and a solvent and mix them, both of them are not changed unless the setting of the measured value is changed. The mixing ratio is always constant, and there is no concern that the mixing ratio will be different between each set, such as when using multiple sets of stock solution weighing tanks and solvent weighing tanks alternately, and changes in concentration due to changes in the mixing ratio. Can be reliably prevented.

According to a preferred embodiment of the present invention, the mixing tank and the supply tank each have a temperature adjusting means, and the temperature adjusting means adjusts the temperature of the abrasive liquid, thereby providing a polishing apparatus. The temperature of the supplied abrasive liquid can always be kept constant.

According to another preferred embodiment of the present invention,
The suction end of the supply pipe in the above-mentioned stock solution transfer pipe for metering opens to a height near the inner bottom of the stock solution tank that does not suck in precipitated foreign matter, and the discharge end of the reflux pipe sets near the inner bottom of the stock solution tank. When the foreign material is opened in a height and direction that does not agitate with a jet, and when the liquid level of the stock solution of the polishing material is almost at the same level as the suction end of the supply pipe in the stock solution tank, the residual stock solution of the polishing material remains. A sensor for detecting the quantity as zero is attached.

According to another preferred embodiment of the present invention,
The stock solution metering tank, the mixing tank, and the supply tank each include a stirring means for stirring the stock solution or the stock solution of the polishing material therein. According to another preferred configuration of the present invention, the stock solution metering tank, the mixing tank, and the supply tank each include an inclined bottom portion, and an outlet is formed at the lowest position of the bottom, and the outlet is formed at the outlet. The supply pipes of the transfer pipes are connected to each other. In the present invention, a flushing conduit for supplying and cleaning the cleaning liquid to the tank and the flow path located between the stock solution metering tank and the loading abrasive liquid transfer conduit can be provided.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. The abrasive liquid supplying apparatus shown in FIG. 1 is for accommodating an abrasive stock solution in the form of a slurry. A stock solution tank 1, a stock solution metering tank 4 for measuring an abrasive stock solution sent from the stock solution tank 1 through a stock solution transfer pipe 2 for measurement, and a stock solution sent from a solvent source (not shown) through a solvent supply line 5. A solvent measuring tank 6 for measuring a solvent such as incoming water (preferably pure water) or a chemical liquid, and a weighed abrasive stock solution sent from the undiluted solution metering tank 4 through a mixing undiluted solution transfer pipeline 7. And a mixing tank 9 from which the measured solvent sent from the solvent measuring tank 6 through the mixing solvent transfer pipe 8 is mixed to obtain an abrasive liquid having a required concentration, and a supplying abrasive liquid from the mixing tank 9. Through the transfer line 10 Is a blended abrasive liquid pooled come, and a polishing material liquid supply tank 11 for supplying the polishing apparatus.

The stock solution tank 1 has a sensor 14 for detecting the remaining amount of the stock solution of the polishing material. This sensor 1
Numeral 4 is for detecting the remaining amount from the position of the liquid surface of the abrasive stock solution, which is provided near the bottom of the stock solution tank 1 and gives an alarm of zero remaining level when the liquid level of the abrasive stock solution has dropped to a predetermined level. It emits a signal. However, it is also possible to use a sensor such as a load cell that detects the remaining amount from the weight of the stock solution of the polishing material.

The metering stock solution transfer pipe 2 connecting the stock solution tank 1 and the stock solution metering tank 4 is provided with a supply pipe 16 for supplying the stock solution of the abrasive material in the stock solution tank 1 to the stock solution metering tank 4. It is provided with a reflux pipe 17 which is branched from a part and whose tip is guided into the stock solution tank 1. A pump 18 is connected to the supply pipe 16 and a flow is provided at a branch point between the supply pipe 16 and the reflux pipe 17. A three-way valve 19 for switching the road is provided.

The pump 1 is operated while the supply device is in operation.
8 is always on, whereas valve 19
When the stock solution of the abrasive material is supplied to the stock solution measuring tank 4, the primary side portion 16a and the secondary side portion 16b of the supply pipe 16 are supplied.
When the abrasive stock solution is not supplied to the stock solution metering tank 4, the primary side portion 16a of the supply tube 16 is communicated with the reflux tube 17 to connect the secondary side of the supply tube 16 to the secondary side of the supply tube 16. Portion 16b operates to shut off. Therefore, when the stock solution of the abrasive material is not supplied to the stock solution measuring tank 4,
The stock solution of the polishing material in the stock solution tank 1 is agitated by being constantly refluxed through the primary portion 16a of the supply pipe 16 and the reflux pipe 17, and as a result, the precipitation of fine particles for polishing is prevented and the stock solution of the polishing material is prevented. Is kept constant, and at the same time, clogging of the piping and pump 18 due to drying of the stock solution of abrasive is prevented.

When the supply pipe 16 and the reflux pipe 17 are inserted into the stock solution tank 1, the suction end 16c of the supply pipe 16 is
It is opened at a height that does not suck in the settled foreign matter 20 near the inner bottom of the stock solution tank 1 and at a height that substantially corresponds to the liquid level detected by the sensor 14 when the remaining amount is zero. It is desirable that the discharge end 17a be opened at a height and direction (for example, sideways) so that the precipitated foreign matter 20 near the inner bottom of the stock solution tank 1 is not stirred by the jet flow.

The stock solution measuring tank 4 constituting the measuring section 3
The solvent measuring tank 6 is provided with sensors 22 and 23 for detecting the liquid surfaces of the abrasive stock solution and the solvent, respectively, and these sensors 22 and 23 measure a required amount of the abrasive stock solution and the solvent. The amount measurable by the sensors 22 and 23 can be arbitrarily changed. The stock solution metering tank 4 is provided with a stirrer 24 composed of a stirrer piece 25 and a drive motor 26. The stirrer 24 constantly stirs the stock solution of the abrasive material so that the fine particles for polishing are precipitated. The concentration of the stock solution of abrasive is prevented from changing.

Only one set of the stock solution measuring tank 4 and the solvent measuring tank 6 is provided in the measuring section 3, and by using this set of the stock solution measuring tank 4 and the solvent measuring tank 6, the abrasive stock solution and the solvent are prepared. Is to be weighed. Therefore, even if the setting of the measured value by the sensors 22 and 23 is made slightly wrong, the mixing ratio of the two is always constant unless the set value is changed in the middle, and a plurality of sets of the stock solution measuring tank and the solvent measuring tank are set. There is no concern that the mixing ratio will be different between the respective groups as in the case of using them alternately, and it is possible to reliably prevent the concentration change due to the change of the mixing ratio.

The mixing stock solution transfer pipe 7 connecting the stock solution metering tank 4 and the mixing tank 9 supplies the abrasive stock solution in the stock solution metering tank 4 to the mixing tank 9 and the supply pipe 28. A reflux pipe 29, which is branched from a part and whose tip is led to the stock solution measuring tank 4, is provided with a pump 31 connected to the supply pipe 28, and a flow is provided at a branch point between the supply pipe 28 and the reflux pipe 29. A three-way valve 30 for switching the road is provided.

Then, in a state where the metered stock solution of abrasive is not supplied to the mixing tank 9 through the supply pipe 28, the valve 30 shuts off the secondary side portion 28b of the supply pipe 28 and the primary side portion 28a. And the reflux pipe 29 are communicated with each other, and the pump 31 is operated so that the stock solution of the polishing material in the stock solution metering tank 4 is constantly circulated through the primary portion 28a of the supply pipe 28 and the reflux pipe 29 to be agitated. It As a result, the synergistic effect with the stirring action of the stirring means 24 prevents the fine particles for polishing from being settled and the concentration of the stock solution of the polishing material is kept constant, and at the same time,
It is possible to prevent clogging of the piping and the pump 31 due to the drying of the stock solution of the abrasive material.

Further, when the measured stock solution of abrasive is supplied to the mixing tank 9 through the supply pipe 28, the valve 3 is used.
0 to the primary side portion 28a and the secondary side portion 2 of the supply pipe 28.
8b is communicated with, and the reflux pipe 29 is cut off. Reference numeral 32 in the figure denotes a valve for discharging the stock solution of the abrasive material in the stock solution measuring tank 4, the cleaning solution during the cleaning operation, the drain, and the like.

On the other hand, the mixing solvent transfer pipe line 8 connecting the solvent measuring tank 6 and the mixing tank 9 is constituted only by the supply pipe 33 which can be opened and closed by the two-way valve 34. In this case, the solvent measuring tank 6 is provided at a position higher than the mixing tank 9, and the solvent is supplied to the mixing tank 9 by utilizing the drop. In the figure, 5a is a valve for opening and closing the solvent supply conduit 5, and 5b is a filter for filtering foreign substances in the solvent. At least the stock solution metering tank 4 among the stock solution metering tank 4 and the solvent metering tank 6 has a bottom 4a that is inclined in a conical shape, and an outlet 4b is formed at the lowest position of the bottom 4a. The supply pipe 28 is connected to. As a result, even if the fine particles for polishing are precipitated, they can be surely guided into the supply pipe 28 and sent to the mixing tank 9, or can be agitated by circulation.

The stock solution metering tank 4 may be located higher than the mixing tank 9 or may be located at the same height or lower than the mixing tank 9. Alternatively, the abrasive stock solution may be supplied to the mixing tank 9. In this case, the pump 31 is connected to the reflux pipe 29 side, and when the abrasive stock solution is not supplied to the mixing tank 9, the pump 31 is driven to circulate the abrasive stock solution.

The mixing tank 9 is equipped with a sensor 36 for detecting the liquid level of the abrasive liquid. This sensor 36
Is for detecting the replenishment level of the abrasive liquid, and when the liquid level drops to that position, a replenishment signal is output from the sensor 36, and the undiluted abrasive liquid and solvent are supplied from the measuring unit 3. It has become so. The mixing tank 9 is also provided with a temperature adjusting means 37 for keeping the temperature of the prepared abrasive liquid constant, if necessary. The temperature adjusting means 37 is a heating means 3 arranged in a coil shape.
8 and a cooling means 39, and a temperature sensor (not shown) for measuring the temperature of the polishing liquid.

The heating means 38 and the cooling means 39 are located at a position where they are immersed in the abrasive liquid even when the liquid level of the abrasive liquid is lowered to the replenishment level, for example, at a position lower than the sensor 36. Is desirable. The reason is that when the heating means 38 and the cooling means 39 are exposed when the liquid level of the abrasive liquid is lowered, the adhered abrasive is dried, and when a new abrasive liquid is supplied, the adhered matter is the liquid. This is because they tend to be mixed in and cause damage to the wafer.

Furthermore, the mixing tank 9 has a stirring piece 41.
And a stirring means 40 consisting of a drive motor 42,
By stirring the abrasive liquid with the stirring means 40, the concentration change of the abrasive liquid due to the precipitation of the polishing fine particles is prevented. The stirring means 40 is used for the same reason as the heating means 38 and the cooling means 39.
In order to prevent the exposure of No. 1, the stirring piece 41 is provided at a position where it is immersed in the abrasive liquid even when the liquid level of the abrasive liquid drops to the replenishment level, for example, a position lower than the sensor 36. Is desirable. As another example of the stirring means 40, an absorptive stirring piece that rotates following an external rotating magnetic field is provided at a position lower than the sensor 36 in the mixing tank 9, and a rotating magnetic field generating means is provided outside the tank. I can give you something.

Further, as another example of the stirring means 40,
It is possible to open one or a plurality of injection nozzles at or near the bottom of the mixing tank 9, and inject high-pressure gas such as compressed air from this nozzle to agitate the abrasive liquid. The stirring means using such an injection nozzle is
Not only the mixing tank 9 and the supply tank 11 described above, but also the stirring means 24 of the stock solution mixing tank 4 from which all the measured stock solution of the abrasive material is once discharged can be suitably used.

The above-mentioned supply abrasive liquid transfer pipeline 10 connecting the mixing tank 9 and the supply tank 11 is a supply pipe 45 for supplying the abrasive liquid in the mixing tank 9 to the supply tank 11 and the supply pipe 45. A reflux pipe 46, which is branched from a part and whose leading end is guided to the mixing tank 9, is provided, a pump 47 is connected to the supply pipe 45, and a branch point between the supply pipe 45 and the reflux pipe 46 is provided. A three-way valve 48 for switching the flow path is provided.

When the abrasive liquid is not supplied to the supply tank 11 through the supply pipe 45, the valve 48 shuts off the secondary side portion 45b of the supply pipe 45, and the primary side portion 45a and the reflux pipe. 46 and the pump 47 are operated, and the stock solution of the abrasive material in the stock solution metering tank 4 is supplied to the primary side portion 45 a of the supply pipe 45 and the reflux pipe 4.
It is agitated by constantly circulating through 6. As a result, by the synergistic effect with the stirring action of the stirring means 40, the precipitation of fine particles for polishing is prevented and the concentration of the polishing liquid is kept constant, and at the same time, the piping and pump 47 of the polishing liquid are dried. Prevents clogging.

On the other hand, when the abrasive liquid is being supplied to the mixing tank 9, the valve 48 makes the primary side portion 45a and the secondary side portion 45b of the supply pipe 45 communicate with each other, and the reflux pipe 46 is shut off. ing. Mixing tank 9 above
Comprises a bottom 43 which is conically inclined, the bottom 4
An outlet 44 is formed at the lowest position of the outlet 3.
4 is connected to the supply pipe 45. As a result, even if the polishing fine particles in the abrasive liquid are precipitated, they can be reliably guided into the supply pipe 45 and sent to the supply tank 11, or can be agitated by circulation. Reference numeral 49 in the figure denotes a valve for discharging the abrasive material liquid in the mixing tank 9, the cleaning liquid during the cleaning operation, the drain, and the like.

The supply tank 11 that receives the abrasive liquid from the mixing tank 9 has substantially the same structure as the mixing tank 9. Therefore, the same components as those of the mixing tank 9 are designated by the same reference numerals, and the description thereof will be omitted. The supply tank 11 is provided with a sensor 36a for detecting the replenishment level of the abrasive material liquid, and when the liquid level rises to that position, a replenishment stop signal is output from the sensor 36a to convey the abrasive material from the mixing tank 9. It is desirable to stop the supply of liquid.

The loading abrasive material liquid transfer conduit 12 for supplying the abrasive material liquid in the supply tank 11 to the polishing apparatus includes a supply pipe 50 connected to the outlet 44 of the supply tank 11 and the supply pipe 50. A reflux pipe 51 leading to the upper part of the supply tank 11
And a pump 52 connected to the supply pipe 50, and the supply pipe 50 is connected with a required number of branch pipes 53 individually connected to the respective polishing devices via a valve 54.

The abrasive liquid in the supply tank 11 is
The pump 52 is constantly circulated through the supply pipe 50 and the reflux pipe 51 to prevent the concentration change due to the precipitation of fine particles for polishing being agitated and the clogging of the pipe and the pump 52 due to the drying of the abrasive liquid. . When the polishing apparatus operates, the valve 54 of the corresponding branch pipe 53 opens, and the polishing agent liquid is supplied to the polishing apparatus.

The above-mentioned abrasive liquid supplying device is also provided with a flushing pipe for cleaning a tank and a flow path which come into contact with the abrasive liquid. This flushing line
A cleaning liquid (pure water) source (not shown), a first pipe line 56 connecting the stock solution measuring tank 4 and the solvent measuring tank 6, and a second pipe line 57 connecting the cleaning liquid source to the supply tank 11; A branch portion 56a branched from the first pipe line 56 to the stock solution measuring tank 4 side and a branch portion 56 branched to the solvent measuring tank 6 side.
Valves 58, 59 and 60 for opening and closing are connected to b and the second conduit 57, respectively. If the solvent used for the abrasive liquid is pure water, the flushing first conduit 56 and second flushing conduit 57 may be connected to the solvent supply conduit 5.

In the abrasive liquid supply device having the above-mentioned structure, the abrasive stock solution in the stock solution tank 1 is supplied to the stock solution metering tank 4 through the supply pipe 16 to measure the required amount, and at the same time, the solvent metering tank 6 is also charged with the solvent. Is supplied and weighed,
The measured stock solution of abrasive and the solvent are mixed in the tank 9
By being sent to and mixed therewith, an abrasive liquid having a required concentration can be obtained. The stock solution measuring tank 4 and the solvent measuring tank 6 which have been emptied are supplied with a new stock solution of the abrasive and a solvent, and the next measurement is performed. The abrasive liquid prepared in the mixing tank 9 is sent to the supply tank 11 and supplied from the supply tank 11 to each polishing apparatus through the branch pipe 53.

In the mixing tank 9 whose liquid level has been lowered by transferring the prepared abrasive material liquid to the supply tank 11, the abrasive material stock solution and the solvent which have been measured from the stock solution metering tank 4 and the solvent metering tank 6 are stored. And are sent to prepare a new abrasive liquid. Then, in the supply tank 11, when the level of the abrasive material liquid is lowered by the supply to the polishing device and a replenishment signal is output from the sensor 36, the abrasive material liquid is sent from the mixing tank 9 to the supply tank 11. . Hereinafter, the polishing liquid is supplied to the polishing apparatus by automatically repeating the same steps.

At this time, each of the tanks 1, 4, 9, 11
In the above, since the polishing agent stock solution or the polishing agent solution in the tank is circulated through the supply tube and the reflux tube of the transfer pipeline connected to them, the polishing agent is agitated. This prevents changes in the concentration of the stock solution or the polishing agent solution, and also prevents clogging of pipes and pumps due to drying.

Further, in preparing the abrasive liquid, only one set of the stock solution metering tank 4 and the solvent metering tank 6 is provided in the metering section 3 and these are repeatedly used, so that the setting of the metering value is changed. As long as the mixing ratio of the stock solution of the abrasive and the solvent is always constant, there is no concern that the mixing ratio will be different between each set, such as when using multiple sets of stock solution measuring tank and solvent measuring tank alternately. Therefore, it is possible to reliably prevent the change in the concentration of the abrasive liquid due to the change in the mixing ratio.

Further, by adjusting the temperature of the abrasive liquid by the temperature adjusting means 37 provided in each of the mixing tank 9 and the supply tank 11, the temperature of the abrasive liquid supplied to the polishing apparatus can be always kept constant. As a result, the property of the abrasive liquid does not change due to temperature change.

Further, the cleaning of the tanks, flow paths, etc. which come into contact with the abrasive liquid is carried out as follows, whereby the abrasive containing no impurities can be always supplied. First, the undiluted solution measuring tank 4 and the flow path associated therewith will be described. With the valve 30 communicating the primary side portion 28a of the supply pipe 28 and the reflux pipe 29, the valve 32 is provided.
To discharge the stock solution of the abrasive material in the tank 4, close the valve 32, and open the valve 58 connected to the branch portion 56a of the first conduit 56 to supply the cleaning solution to the stock solution measuring tank 4 in the required amount. .

When the cleaning liquid is accumulated in the tank 4, the pump 31 circulates the cleaning liquid through the primary side portion 28a of the supply pipe 28 and the reflux pipe 29 to clean the stock solution measuring tank 4 and the circulation path. To do. When the cleaning is completed, the valve 32 is opened, the cleaning liquid is discharged, and then the valve 32 is closed again.

Next, the valve 30 is switched to supply the supply pipe 28.
The primary side portion 28a and the secondary side portion 28b are communicated with each other,
In this state, the valve 58 is opened, and the cleaning liquid is flowed from the stock solution measuring tank 4 to the supply pipe 28 to clean the supply pipe 28. The cleaning liquid flowing into the mixing tank 9 through the supply pipe 28 is discharged through the valve 49. Thus, when the cleaning of the supply pipe 28 is completed, the valve 58 is closed and the cleaning of the stock solution metering tank 4 and the flow path related thereto is completed.

The cleaning of the mixing tank 9 and the flow path associated therewith is performed as follows. First, the valve 49 is opened to discharge the abrasive liquid in the tank 9, then the valve 49 is closed, and the valve 59 and the supply pipe 3 in the branch portion 56b are closed.
The valve 34 in 3 is opened, and the required amount of cleaning liquid is supplied to the mixing tank 9 through the solvent measuring tank 6. When the cleaning liquid is accumulated in the mixing tank 9, the cleaning liquid is circulated by the pump 47 through the primary side portion 45a of the supply pipe 45 and the reflux pipe 46 to clean the mixing tank 9 and the circulation path. When the cleaning is completed, the valve 49 is opened and the cleaning liquid is discharged. In this case, it is desirable to provide the mixing tank 9 with a sensor that detects the upper limit of the cleaning liquid.

Next, the valve 48 is switched to switch the supply pipe 45.
The primary side portion 45a and the secondary side portion 45b are brought into communication with each other, and the cleaning liquid is caused to flow from the solvent measuring tank 6 through the mixing tank 9 again to clean the supply pipe 45. This completes the cleaning of the stock solution metering tank 4 and the flow path associated therewith. The cleaning liquid flowing into the supply tank 11 through the supply pipe 45 is discharged through the valve 49.

Further, in order to clean the supply tank 11 and the flow path related thereto, first open the valve 49 to open the tank 1.
After discharging the abrasive liquid in 1, the valve 49 is closed,
The valve 60 in the second conduit 57 is opened to supply the required amount of cleaning liquid to the supply tank 11. When the cleaning liquid is accumulated in the supply tank 11, the pump 52 circulates the cleaning liquid through the supply pipe 50 and the reflux pipe 51 to clean the supply tank 11 and the circulation path. When the cleaning is completed, the valve 49 is opened and the cleaning liquid is discharged to complete the cleaning. When the solvent is the same pure water as the cleaning liquid, the branch portion 56b of the first conduit 56 and the valve 59 may be omitted and the cleaning liquid may be supplied to the solvent measuring tank 6 through the solvent supply conduit 5. . Further, reference numeral 61 in the drawing denotes an oxidizing material supply pipe, which can supply the oxidizing material to the mixing tank through this pipe 61 when cleaning is not performed.

[0047]

As described above, according to the present invention, the abrasive stock solution and the abrasive solution in each tank are circulated and agitated to prevent the fine particles for polishing contained therein from precipitating so that the concentration due to the precipitation can be increased. In addition to preventing changes, the set of stock solution metering tank and solvent metering tank was used to measure the stock solution of the abrasive material and the solvent to prevent changes in concentration due to changes in the mixing ratio. It is possible to reliably prevent the property change due to the change in the concentration, and to reliably supply the polishing liquid with a certain property to the polishing apparatus, and at the same time prevent the piping and pump from being clogged due to the drying of the polishing liquid. be able to.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a position embodiment of an abrasive liquid supply device according to the present invention.

[Explanation of symbols]

1 undiluted solution tank 2 undiluted solution transfer pipeline 3 metering section 4 undiluted solution metering tank 4a, 43 bottom 4b, 44 outlet 6 solvent metering tank 7 mixing undiluted solution transfer tube 8 mixing solvent transfer tube 9 mixing tank 10 supply Abrasive liquid transfer pipe 11 Supply tank 12 Abrasive liquid transfer pipe for load 14 Sensor 16, 28, 45, 50 Supply pipe 16c Suction end 17, 29, 46, 51 Reflux pipe 17a Discharge end 18, 31, 47, 52 pump 20 foreign matter 24, 40 stirring means 37 temperature adjusting means

Claims (6)

[Claims] 1. A stock solution tank for containing a slurry-like stock solution of an abrasive material; a stock solution measuring tank for measuring a stock solution of an abrasive material from the stock solution tank, and a solvent measuring tank for measuring a solvent from a solvent source; A measuring unit provided with only a set; a mixing tank for mixing an undiluted abrasive solution and a solvent weighed in each of the above-mentioned measuring tanks to obtain an abrasive solution having a required concentration; and receiving an abrasive solution prepared in the above mixing tank Polishing material liquid supply tank for supplying to the polishing device; a supply pipe provided between the stock solution tank and the stock solution measuring tank, for supplying the stock solution of the polishing material in the stock solution tank to the stock solution measuring tank, and a part of the supply pipe Equipped with a reflux pipe whose end is led to the undiluted solution tank and a pump for pumping the undiluted solution of abrasive material, and when the undiluted solution of abrasive material is not supplied to the undiluted solution tank, the abrasive material in the undiluted solution tank Undiluted solution above the supply pipe A stock solution transfer pipe for circulation that circulates through a reflux pipe; a supply pipe provided between the stock solution metering tank and the mixing tank to supply the abrasive stock solution in the stock solution metering tank to the mixing tank; Equipped with a reflux pipe having a tip branched to a stock solution metering tank and a pump for pumping the stock solution of abrasive material, and when the stock solution of abrasive material is not supplied to the mixing tank, A stock solution transfer pipeline for mixing, which circulates the stock solution of abrasive through the supply pipe and the reflux pipe; for mixing, which is provided between the solvent measuring tank and the mixing tank and supplies the solvent in the solvent measuring tank to the mixing tank Solvent transfer pipe line; a supply pipe provided between the mixing tank and the supply tank for supplying the abrasive liquid in the mixing tank to the supply tank; and a mixing tank having a tip branched from a part of the supply pipe Led to A reflux pipe and a pump for pumping the abrasive liquid, and at least when the abrasive liquid is not supplied to the supply tank, the abrasive liquid in the mixing tank is circulated through the supply pipe and the reflux pipe. Supplying abrasive material liquid transfer line; a supply pipe provided between the supply tank and the polishing apparatus for supplying the polishing agent solution in the supply tank to the polishing apparatus; and a reflux pipe for guiding the supply tube to the supply tank. A pipe and a pump for pumping the abrasive liquid, and an abrasive liquid transfer pipe for load for constantly circulating the abrasive liquid in the supply tank through the supply pipe and the reflux pipe. Abrasive liquid supply device for chemical mechanical polishing. 2. The abrasive liquid supply apparatus for chemical mechanical polishing according to claim 1, wherein the mixing tank and the supply tank each have a temperature adjusting means for adjusting the temperature of the abrasive liquid. 3. The polishing agent liquid supply apparatus for chemical mechanical polishing according to claim 1 or 2, wherein the suction end of the supply pipe in the metering stock solution transfer pipeline is near the inner bottom of the stock solution tank. The outlet end of the reflux pipe is opened at a height and direction that does not agitate the precipitated foreign matter near the inner bottom of the stock solution tank, and the above stock solution tank is polished. A sensor is attached to detect the remaining amount of the stock solution as zero when the surface level of the stock solution becomes almost the same as the suction end of the supply pipe. 4. The abrasive liquid supply device for chemical mechanical polishing according to claim 1, wherein the stock solution metering tank, the mixing tank, and the supply tank have an internal stock solution of abrasive material or an abrasive material. Each is equipped with a stirring means for stirring the liquid. 5. The polishing agent liquid supply apparatus for chemical mechanical polishing according to claim 1, wherein the stock solution metering tank, the mixing tank, and the supply tank each have an inclined bottom portion. An outlet is formed at the lowest position of the bottom, and a supply pipe of a transfer pipe is connected to the outlet. 6. The abrasive liquid supply device for chemical mechanical polishing according to claim 1, wherein the tank is located between the stock solution metering tank and the abrasive liquid transfer pipe for load. Those that have a flushing conduit that supplies the cleaning liquid to the flow path.