JP2005294350A - Polishing solution supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize precision of mixed ratio and amount of supply, to supply polishing solution without deterioration and with stable quality to a polishing device, to simplify the device and to improve reliability. <P>SOLUTION: The device is provided with undiluted solution tanks 1, 3 and 5 storing a plurality of undiluted solutions 2, 4 and 6 different in components; an aggregation part 33 making a plurality of undiluted solutions join; tubular objects 27, 29 and 31, whose one end is opened to the undiluted solutions 2, 4 and 6 and the other end to the aggregation part 33 and which have prescribed lengths; and a discharge means 39 discharging a plurality of the undiluted solutions to the polishing device 41 through the tubular objects 27, 29 and 31, the aggregation part 33, and a discharge line 36. The number of the tubular objects 27, 29 and 31 connected to the aggregation part 33 and the undiluted solutions 2, 4 and 6 is varied, and the mixed ratio of a plurality of the undiluted solutions 2, 4 and 6 is set. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polishing liquid supply apparatus that supplies a polishing liquid (slurry) to chemical mechanical polishing (hereinafter abbreviated as CMP) particularly when performing planar processing of a semiconductor substrate surface in semiconductor manufacturing.

  In recent years, the CMP method has attracted attention as a fine processing technique for high integration and high performance of semiconductor devices. This CMP is a polishing method in which the chemical action between the polishing liquid (slurry) and the object to be polished and the mechanical action of the abrasive grains in the polishing liquid are combined. This is an indispensable step in the planarization of the interlayer insulating film, the formation of the metal plug, and the buried metal wiring type in the forming process.

  As a polishing apparatus used in this CMP, a disk-shaped polishing surface plate having a polishing cloth affixed to the surface, and a plurality of wafers that hold one surface of the wafer to be polished and abut the other surface of the wafer against the polishing cloth A wafer holding head and a head driving mechanism for rotating these wafer holding heads relative to a polishing surface plate, and performing polishing by supplying a polishing liquid containing abrasive grains between the polishing cloth and the wafer. Conventionally known.

  In the CMP, it is extremely important to maintain the accuracy of the mixing ratio and supply amount of a plurality of stock solutions of the polishing liquid, and to prevent aggregation and sedimentation. Are known.

  There are a number of suction ports corresponding to each solution for sucking each solution for slurry mixing, and a discharge port for supplying slurry to the chemical mechanical polishing apparatus, from each suction port to the discharge port A suction pump (supply pump) for sucking each liquid from a suction port at a specific amount with a constant mixing ratio and discharging each sucked liquid to the discharge port side in each liquid supply path A slurry mixing and supplying device that is disposed and provided with a damper and a pressurizing valve in the discharge side supply path of each supply pump, and at least the stock slurry of each liquid sucked from each suction port, A means for circulating at a flow rate and pressure exceeding a specific amount consumed by the chemical mechanical polishing apparatus by a circulation pump, and a value obtained by continuously measuring the pressure fluctuation of the circulating liquid flow of the raw slurry, at least for the raw slurry. In which a control device for correcting a discharge amount from the supply pump. (For example, see Patent Document 1)

Further, in a slurry supply apparatus supplied to a wafer polishing apparatus by a chemical mechanical polishing method, an abrasive aqueous solution supply means for supplying an aqueous solution of abrasive grains through a constant flow valve and an orifice; An additive solution supply means for supplying an additive solution from a tank through a constant flow valve and an orifice. The abrasive aqueous solution and the additive solution supplied from each of the supply means are sucked with a pump and joined together to obtain a polishing constant. Immediately before spraying onto the board, the two solutions are mixed by a mixer having an ultrasonic device to form a slurry. (For example, see Patent Document 2)
JP 2003-071720 A JP 2000-202774 A

  However, in the slurry supply apparatus described in Patent Document 1 described above, the mixing ratio and flow rate of each stock solution of slurry discharged to the chemical mechanical polishing device are determined by circulating pump the stock solution slurry in each drum (tank). In order to cause each liquid to be sucked into the circulation path of the circulating path and the circulation path of each liquid in a specific amount with a fixed mixing ratio from each suction port, and to discharge each sucked liquid to the discharge port side Basically, it is set by the suction pumps arranged respectively. In this configuration, the pressure of the circulation path of each liquid is likely to fluctuate, and furthermore, the mixing ratio of each stock solution and the total flow rate of the mixed stock solution are changed by the flow rate fluctuations of the suction pumps respectively arranged from the circulation paths of each liquid. It tends to cause variation. In addition, although a suction pump correction mechanism for pressure fluctuations in the liquid flow due to pulsation of the circulating pump is incorporated, the configuration becomes complicated. Furthermore, when a problem occurs in at least one of the plurality of suction pumps, there is a problem that the mixing ratio of each stock solution is significantly changed.

  Further, in the slurry supply apparatus described in Patent Document 2 described above, the mixing ratio and flow rate of the slurry are basically set by the inner diameter of the orifice, and further the flow meter and the opening degree by receiving feedback thereby. This is done by controlling a constant flow valve that adjusts the flow rate. However, the diameter of the orifice is different between the aqueous solution side and the additive solution side of the abrasive grains, but is about φ1.0 mm on the abrasive grain side and about 1/5 (φ0.2) on the additive solution side. As a result, there is a risk of substantial diameter reduction or clogging due to the stock solution slurry or foreign matter. Even in the constant flow rate valve, a similar phenomenon may occur due to the configuration of the minute gap. With such a configuration, it may not be possible to accurately supply a slurry having a specific mixing ratio suitable for a desired process.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and improves the accuracy and stability of the mixing ratio and supply amount of a plurality of stock solutions for polishing liquid, and provides a polishing apparatus for polishing liquid with stable quality without deterioration. It is an object of the present invention to provide a polishing liquid supply device that can improve the reliability of the supply, the device, and the reliability.

  The polishing liquid supply apparatus of the present invention includes a plurality of stock solution tanks each storing a plurality of stock solutions having different components, a collecting portion for joining the plurality of stock solutions, and one end in each stock solution in the plurality of stock solution tanks. A tubular body having a certain length with an opening and the other end opened to the collecting portion, and a discharge means for discharging the plurality of stock solutions to a polishing apparatus via the tubular body, the collecting portion, and a discharge line, The mixing ratio of the plurality of stock solutions is set such that the number of tubular bodies communicating with each stock solution in the collecting portion and each of the stock solution tanks is different.

  According to the polishing liquid supply apparatus of the present invention, it is possible to stabilize the accuracy of the mixing ratio and supply amount of a plurality of stock solutions for polishing liquid, supply the polishing liquid with stable quality without deterioration to the polishing apparatus, and the apparatus Can be simplified and the reliability can be improved.

  The first invention in the polishing liquid supply apparatus of the present invention is a plurality of stock solution tanks each storing a plurality of stock solutions having different components, a collecting section for joining the plurality of stock solutions, and one end of the stock solution tank in the plurality of stock solution tanks. A tubular body having a certain length opened in each stock solution and the other end opened in the collecting portion, and a discharge for discharging the plurality of stock solutions to the polishing apparatus via the tubular body, the collecting portion, and a discharge line And a mixing ratio of the plurality of stock solutions is set such that the number of tubular bodies communicating with the stock solution in each stock solution in the plurality of stock solution tanks is different. It is.

  As a result, the mixing ratio and supply accuracy of multiple stock solutions for polishing liquid are stabilized, supply of polishing liquid with stable quality without deterioration to the polishing equipment, simplification of equipment, and improvement of reliability. Can be achieved.

  The second invention is characterized in that in the first invention, tubular bodies having different cross-sectional areas or tubular bodies having different lengths are included.

  As a result, the mixing ratio of the plurality of stock solutions can be arbitrarily set wider.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, a small number of stock solution tubular bodies are opened at the central portion of the gathering portion having a circular cross section, and a large number of undiluted solution tubular bodies are formed on the outside. Are arranged and opened.

  As a result, centering on the stock solution that is the abrasive fine particle dispersion, the stock solution that is the additive dispersion on the outside, and the stock solution that is pure water for dilution on the outermost periphery are discharged into the collecting section, and the interface of each flow is It is easy to collapse due to the difference in density and can be supplied as a uniformly mixed polishing liquid by promoting dispersion and mixing.

  According to a fourth invention, in any one of the first to third inventions, a control valve for opening and closing a passage of each tubular body is provided.

  As a result, the mixing ratio of the plurality of stock solutions can be arbitrarily set wider.

  A fifth invention is the invention according to any one of the first to fourth inventions, wherein a plurality of collecting portions for joining a plurality of stock solutions having different components are provided, and one end of each of the plurality of collecting portions is the plurality of stock solution tanks. A tubular body having a certain length that is opened in each of the undiluted solution and the other end is opened in the gathering portion is provided so that the polishing liquid can be discharged to a plurality of discharge lines.

  As a result, the polishing liquid can be supplied from a single group of stock solution tanks to a plurality of polishing apparatuses in parallel, and the apparatus can be greatly simplified and the occupied space can be reduced.

  A sixth aspect of the invention is characterized in that, in the fifth aspect of the invention, the polishing liquid to at least one discharge line is changed in the mixing ratio or the discharge amount among the discharges of the polishing liquid to a plurality of discharge lines. This is a liquid supply device.

  As a result, the discharge of polishing liquids with different mixing ratios can be arbitrarily selected so that the number of tubular bodies communicating with the respective stock solutions in the collecting section and the plurality of stock solution tanks is different for each of the plurality of system discharge lines. Can be supplied to a plurality of polishing apparatuses. Further, by changing the ability of the discharge means, it is possible to supply polishing liquids having different discharge amounts to a plurality of polishing apparatuses.

  According to a seventh invention, in any one of the first to sixth inventions, any one of the plurality of stock solutions is pure water, to a certain time before the start of discharge to the plurality of stock solutions, or to the plurality of stock solutions. In this case, only the pure water is discharged to the collecting portion for a certain time after stopping the discharge.

  As a result, only the pure water stock solution is discharged to the collecting part for a certain period of time, and each part can be washed to always maintain the mixing ratio and the supply amount with high accuracy.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
A polishing liquid supply apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram of a polishing liquid supply apparatus according to a first embodiment of the present invention, FIG. 2 is an enlarged configuration diagram of a collecting portion in FIG. 1, and FIG. 4 to 7 are other configuration diagrams of the polishing liquid supply apparatus of the first embodiment. Embodiment 1 of the present invention will be described below with reference to the drawings.

  In the figure, a stock solution 2 which is an abrasive fine particle dispersion for a polishing liquid such as silica, ceria, alumina, zirconia, manganese dioxide, etc. is placed in a stock solution tank 1 with an acidic agent such as hydrogen peroxide or an alkaline agent such as ammonia. A stock solution 4 that is an additive dispersion containing additives is stored in the stock solution tank 3, and a stock solution 6 that is pure water for dilution is stored in the stock solution tank 5. A replenishment tank 7 for supplying the abrasive fine particle dispersion into the stock solution tank 1 is provided. The replenishment tank 7 includes a pump 8 and a circulation path 9, and the abrasive fine particle dispersion in the replenishment tank 7 is supplied. It is circulated at a constant flow rate and pressure to prevent sedimentation of the abrasive fine particles and maintain dispersibility by the stirring effect. Further, a supply pipe 10 communicating from a part of the circulation path 9 into the stock solution tank 1 is provided, a control valve 11 is positioned in the supply pipe 10, and a discharge pipe 12 is provided from the control valve 11.

  The replenishment tank 13 for supplying the additive dispersion containing the additive into the stock solution tank 3 is provided. The replenishment tank 13 includes a pump 14 and a circulation path 15. The agent dispersion is circulated at a constant flow rate and pressure to maintain the dispersibility by the stirring effect. Further, a supply pipe 16 communicating from a part of the circulation path 15 into the stock solution tank 3 is provided, a control valve 17 is positioned in the supply pipe 16, and a discharge pipe 18 is provided from the control valve 17. A supply pipe 19 for supplying the stock solution 6 which is pure water into the stock solution tank 5 is provided and connected to a separate pure water supply device (not shown) via a control valve 20.

  A load cell (weight detection means) 21 is provided below each of the stock solution tanks 1, 3, and 5, and a capacitive liquid level sensor 22 that detects the level of the stock solution 2 in the stock solution tank 1 is provided. An optical liquid level sensor 23 for detecting the liquid levels of the stock solutions 4 and 6 in the stock solution tanks 3 and 5 is provided. Each stock solution tank 1, 3, 5 keeps a constant liquid level and stores each, and in the space (cavity) on the liquid level of each stock solution 2, 4, 6, nitrogen gas having a constant wetness, etc. The inert gas is maintained at a constant pressure (for example, atmospheric pressure).

  The control unit 42 determines whether the output value from each load cell (weight detection means) 21 and the liquid level sensors 22 and 23 maintains the preset liquid level at either the lower limit, the upper limit, or both. Based on the result of determination by a computing means (not shown) provided, a control valve 11 located in the supply pipe 10 communicating from a part of the circulation path 9 into the stock solution tank 1 and a part of the circulation path 15 from the stock solution tank The control valve 17 positioned in the supply pipe 16 communicating with the inside 3 and the control valve 20 positioned in the pure water supply pipe 19 are opened and closed or the opening degree is linearly controlled to control the inside of each of the stock solution tanks 1, 3, 5. The liquid level is kept constant. The replenishment tank 7 and the replenishment tank 13 are used for grasping and exchanging the amount of each replenishment stock solution. The stock solution tank 1 is provided with a stirring means 26 for preventing sedimentation of abrasive fine particles and maintaining dispersibility.

  In addition, although a capacitance type liquid level sensor 22 is provided to detect the level of the stock solution 2 that is the abrasive fine particle dispersion in the stock solution tank 1, this can also be detected from the outside of the stock solution tank 1. Therefore, various measuring means other than the measuring means such as the differential pressure type and the ultrasonic type can be adopted including the optical liquid level sensor 23. Further, in order to maintain the stock solution tanks 1, 3, and 5 at a constant liquid level, only the liquid level sensor may be used.

  The polishing liquid supply device is installed in a room controlled at a constant temperature, and in particular, the temperatures of the stock solutions 2, 4, and 6 are kept constant. Further, each stock solution tank 1, 3 and 5 is preferably provided with a thermostatic means (not shown). This prevents an excessive temperature stress from being applied to the polishing fluid and prevents quality degradation such as agglomeration of abrasive grains due to the temperature stress, so that a polishing fluid with a stable quality can be supplied. Furthermore, it is also preferable in that the flow rate accuracy is stabilized by maintaining the properties such as the viscosity and density of the stock solutions 2, 4, and 6 constant. The isothermal means is a means for isolating the polishing fluid to a preset reference temperature, and detects the temperature of the polishing fluid and heats or cools each stock solution according to the detected temperature. .

  Further, a pure water supply pipe 24 for supplying pure water for cleaning the interior to the stock solution tanks 1 and 3 is connected to a control valve 25, and the pure water supply pipe 24 is provided as a separate pure water supply device (not shown). ). The stock solution tank 1 is provided with a stirring means 26 for preventing sedimentation of the abrasive fine particles and maintaining dispersibility.

  Each stock solution 2, 4, 6 in each stock solution tank 1, 3 has tubular bodies 27, 29, 31 opened at one end, and the other ends of the tubular bodies 27, 29, 31 are connected to the assembly The part 33 is opened. Further, the tubular bodies 27, 29, 31 are provided with control valves 28, 30, 32 for opening and closing the passages. The tubular bodies 27, 29, and 31 have a certain length, an inner diameter of, for example, 2 mm to 3 mm, and a cross section is not limited to a circle but may be a polygonal shape.

  Further, as shown in FIG. 3, the tubular bodies 27, 29 and 31 opened in the collecting portion 33 are opened in the central portion of the collecting portion having a circular cross section in which the small number of the tubular bodies 27 of the stock solution 2 are opened. On the outside, the tubular bodies 29 and 31 of the stock solutions 4 and 6 having a large number are sequentially arranged and opened. That is, a tubular body of a small amount of undiluted solution having a small mixing ratio is opened at the central part of the gathering portion having a circular cross section, and a tubular body of a large amount of undiluted solution having a large mixing ratio is opened outside this.

  A control valve 34 is provided in communication with the collecting portion 33, and a pure water supply pipe 35 is connected to the control valve 34. Further, the control valve 34 is connected to a discharge line 36 serving as a passage for the polishing liquid obtained by mixing the respective stock solutions 2, 4, 6 in the collecting portion 33. A control valve 37 is positioned in the middle of the discharge line 36, and a discharge pipe 38 is connected to the control valve 37. Furthermore, a suction pump 39 as discharge means for discharging the polishing liquid from the discharge port 40 to the polishing device 41 is provided at the tip of the discharge line 36. As the suction pump 39, a tube diaphragm type, a bellows type, or a diaphragm type can be used.

  Although the polishing apparatus 41 is not shown, a disk-shaped polishing surface plate having a polishing cloth affixed to the surface, and a plurality of wafers that hold one surface of the wafer to be polished and abut the other surface of the wafer on the polishing cloth A holding head and a head drive mechanism for rotating these wafer holding heads relative to the polishing surface plate, and polishing is performed by supplying a polishing liquid (slurry) containing abrasive grains between the polishing cloth and the wafer. It is.

  The control unit 42 controls the entire polishing liquid supply apparatus. The control unit 42 includes the control valves 11, 17, 20, 25, 28, 30, 32, 34, 37, and discharge means. A suction pump 39, a load cell (weight detection means) 21, liquid level sensors 22 and 23, and circulation pumps 8 and 14 for the replenishment tank 7 are connected.

  Further, the configuration shown in FIG. 4 is a configuration in which the suction pump 43 is connected to the collecting portion 33 with respect to the configuration in which the suction pump 39 as the discharge means is disposed near the discharge port 40 in FIG. It is.

  Further, in the configuration shown in FIG. 5, a plurality of suction pumps 43 as discharge means are connected to the collecting portion 33 and connected to discharge lines 36 corresponding to the respective suction pumps 43. It is comprised so that it may supply.

  In the configuration shown in FIG. 6, a plurality of suction pumps 44 and 46 as discharge means are connected to the collecting portion 33, and the discharge sides of the suction pumps 44 and 46 join to discharge the polishing liquid to the discharge line 36. And is configured to be discharged from the discharge port 40 to the polishing apparatus 41. Control valves 45 and 47 for opening and closing the flow paths are provided on the suction side and the discharge side of the respective suction pumps 44 and 46. The suction pumps 44 and 46 and the control valves 45 and 46 are connected to the control unit 42.

  Next, the basic operation and action of the polishing liquid supply apparatus configured as described above will be described below. 1-6, stock solution 2 of an abrasive fine particle dispersion, which is an aqueous solution containing abrasive grains such as silica, ceria, alumina, zirconia, manganese dioxide, etc., for polishing liquid is stored in stock solution tank 1, and hydrogen peroxide A stock solution 4 that is an additive dispersion containing an acidic agent such as ammonia, an alkaline agent such as ammonia, and a surfactant additive is stored in the stock solution tank 3, and a stock solution 6 that is pure water for dilution or washing is further stored. It is stored in the stock solution tank 5. Each stock solution 2, 4, 6 maintains a constant liquid level and is stored respectively. In the space on the liquid level of each stock solution 2, 4, 6, nitrogen gas having a certain degree of wetness, etc. The inert gas is maintained at a constant pressure (for example, atmospheric pressure). Each combination of abrasive fine particle dispersion, additive dispersion, and pure water is selected according to the object to be polished.

  Next, the control valves 28, 30, 32 are opened, the control valve 34 communicated with the collecting portion 33 is closed on the pure water supply pipe 35 side, the discharge line 36 side is opened, and the control valve located in the middle of the discharge line 36. 37, the discharge pipe 38 side is closed and the discharge line 36 side is opened, and the suction pump 39 as the discharge means is driven. When the suction pump 39 is driven, the stock solutions 2, 4, 6 in the stock solution tanks 1, 3, 5 are sucked from the tubular bodies 27, 29, 31 and discharged to the collecting portion 33 for mixing. The mixed liquid flows into the discharge line 36 as a polishing liquid and is supplied from the discharge port 40 to the polishing apparatus 41.

  The mixing ratio of the plurality of stock solutions is such that the number of tubular bodies 27, 29, 31 communicating with the collecting portion 33 and each of the stock solutions 2, 4, 6 in the stock solution tanks 1, 3, 5 is different. Is set. For example, when the number of the tubular bodies 27 that communicate with the stock solution 2 that is the abrasive fine particle dispersion is one, 5 to 8 tubular bodies 29 that communicate with the stock solution 4 that is the additive dispersion containing the additive, 9 to 12 tubular bodies 29 communicating with the stock solution 6 which is pure water for dilution are used in the stock solution 2, 4 and 6 in the collecting portion 33 and the plurality of stock solution tanks 1, 3, and 5. The mixing ratio of each of the stock solutions 2, 4, and 6 can be arbitrarily set by selecting the number of tubular bodies communicating with each other. The supply amount of the polishing liquid that is a mixed liquid of each of the stock solutions 2, 4, and 6 supplied from the discharge port 40 to the polishing apparatus 41 can be arbitrarily set and adjusted by controlling the capacity of the suction pump 39.

  Further, by including a tubular body having a different cross-sectional area or a tubular body having a different length for each of the stock solutions 2, 4, 6 or the same stock solution, the mixing ratio of each stock solution 2, 4, 6 is It can be set wider.

  Further, by providing the control valves 28, 30, and 32 for opening and closing the passages of the tubular bodies 27, 29, and 31, respectively, the stock solutions 2, 4 and 4 in the collecting portion 33 and the plurality of stock solution tanks 1, 3, and 5 are provided. , 6, and the number of tubular bodies 27, 29, 31 that can pass through the respective stock solutions 2, 4, 6 can be arbitrarily selected. As a result, the mixing ratio of each of the undiluted solutions 2, 4, and 6 can be set more widely. Further, control can be performed in response to a change in the initial setting of the mixing ratio of the polishing apparatus 41 and a change in the mixing ratio during polishing. The valve 28, 30, 32 can be dealt with finely by opening and closing operations.

  In FIG. 1, tubular bodies 27, 29, 31 in which one end is opened in each stock solution 2, 4, 6 in each stock solution tank 1, 3, 5 and the other end is opened in the collecting portion 33. However, the number of the tubular bodies 27, 29, 31 is the same in each of the stock solutions 2, 4, 6, and the passages of the tubular bodies 27, 29, 31 are the same. Depending on the number of control valves 28, 30, and 32 that are opened and closed, the collecting portion 33 communicates with each of the stock solutions 2, 4, 6 in the plurality of stock solution tanks 1, 3, 5, and each stock solution 2 The mixing ratio of each of the stock solutions 2, 4, 6 may be set by arbitrarily selecting the number of tubular bodies 27, 29, 31 that can pass through 4, 6 and 6.

  In addition, the suction pump 39 that sucks each of the stock solutions 2, 4, and 6 is used as the discharge means. However, a certain degree of wetness is present on the surface of the stock solutions 2, 4, and 6 in the stock solution tanks 1, 3, and 5. It is also possible to apply pressure with an inert gas such as nitrogen gas to extrude the stock solutions 2, 4 and 6 and discharge them.

  Moreover, although the case where the polishing liquid composed of three kinds of undiluted solutions of each of the undiluted solutions 2, 4 and 6 has been described, the polishing liquid composed of two types of undiluted solutions is supplied according to the required specifications of the polishing apparatus 41 However, the present invention is not limited to this embodiment.

  Further, as shown in FIG. 3, the tubular bodies 27, 29, 31 communicated with the collecting portion 33 are formed by opening the small number of the tubular bodies 27 of the stock solution 2 in the central portion of the collecting portion having a circular cross section. The tubular bodies 29 and 31 of the stock solutions 4 and 6 having a large number are sequentially arranged and opened on the outside. As a result, the stock solution 2 that is the abrasive fine particle dispersion is centered, the stock solution 4 that is the additive dispersion is discharged to the outside, and the stock solution 6 that is pure water for dilution is discharged into the collecting portion 33 on the outermost periphery. The interface of the flow is apt to collapse due to the difference in density, and dispersion and mixing are promoted, so that it can be supplied as a uniformly mixed polishing liquid.

  In addition, a means for promoting mixing may be added to the collecting portion 33. In this case, even in a state where a lower flow rate of the polishing liquid is supplied, it can be supplied as a uniformly mixed polishing liquid. Further, mixing is also promoted in the discharge line 36 and the suction pump 39 until the polishing liquid reaches the discharge port 40.

  Further, before starting the operation of the suction pump 39 as the discharge means, the control valves 28 and 30 provided in the tubular bodies 27 and 29 that open to the stock solutions 2 and 4 are closed, and the tubular body 31 that opens to the stock solution that is pure water is provided. The provided control valve 32 is opened. After that, when driving of the suction pump 39 is started, only pure water is sucked and discharged to the collecting portion 33 and further discharged from the discharge line 36 to the polishing apparatus 41. As a result, the collecting portion 33, the discharge line 36, the control valves 34 and 37, and the suction pump 39 can be washed with pure water. At this time, the polishing apparatus 41 collects pure water. Further, when only pure water is discharged, the passage between the control valves 37 can be washed from the collecting portion 33 by switching the passage so that the control valve 37 communicates with the discharge pipe 38. After discharging pure water only for a certain period of time, the control valves 28 and 30 provided in the tubular bodies 27 and 29 that open to the stock solutions 2 and 4 are also opened, so that a normal polishing liquid supply operation is started. .

  When stopping the supply of normal polishing liquid, control valves 28 and 30 provided in the tubular bodies 27 and 29 opened to the stock solutions 2 and 4 are stopped before stopping the suction pump 39 as a discharge means. If the control valve 32 provided on the tubular body 31 that opens from the open to the stock solution that is pure water is left open, only pure water is sucked and discharged to the collecting portion 33, and the polishing device 41 is further discharged from the discharge line 36. It discharges to. As a result, the collecting portion 33, the discharge line 36, the control valves 34 and 37, and the suction pump 39 can be washed with pure water. Further, when only pure water is discharged, the passage between the control valves 37 can be washed from the collecting portion 33 by switching the passage so that the control valve 37 communicates with the discharge pipe 38. After discharging pure water only for a certain time, the control valve 32 is closed and the suction pump 39 is stopped.

  As described above, the pure water stock solution is included in the plurality of stock solutions, and the pure water stock solution is used for a certain period of time before starting the discharge of the plurality of stock solutions to the collecting unit 33 or for a certain time after stopping the discharging of the plurality of stock solutions to the collecting unit 33 By discharging only the liquid to the collecting part 33 and washing each part, the mixing ratio and the supply amount can always be maintained with high accuracy. Furthermore, since the cleaning with pure water can be automatically performed under the control of the control means 42, it is excellent in maintainability.

  The discharge line 36 can also be cleaned by supplying pure water from the pure water supply pipe 35 to the discharge line 36 via the control valve 34.

  When washing the stock solution tanks 1 and 3, the stock solutions 2 and 4 are discharged from the discharge pipes 12 and 18 through the control valves 11 and 17, and then purified from the pure water supply pipe 24 through the control valve 25. This is performed by supplying water into the stock solution tanks 1 and 3.

  Further, the configuration shown in FIG. 4 is a configuration in which a suction pump 43, which is a discharge means, is connected to the collecting portion 33 in contrast to the configuration in which the suction pump 39 is disposed near the discharge port 40 in FIG. It is. As a result, the constitution of the polishing liquid supply device can be integrated and the maintainability can be improved.

  Further, in the configuration shown in FIG. 5, a plurality of suction pumps 43 as discharge means are connected to the collecting portion 33 and connected to discharge lines 36 corresponding to the respective suction pumps 43. It is comprised so that it may supply. As a result, a plurality of polishing apparatuses 41 can be operated simultaneously from a single stock solution tank, and the polishing liquid supply apparatus can be simplified and space-saving can be achieved.

  In the configuration shown in FIG. 6, a plurality of suction pumps 44 and 46, which are discharge means, are connected in parallel to the collecting portion 33, and the discharge sides of the suction pumps 44 and 46 join to discharge the polishing liquid. It is connected to the line 36 and configured to discharge from the discharge port 40 to the polishing apparatus 41. Control valves 45 and 47 for opening and closing the flow paths are provided on the suction side and the discharge side of the respective suction pumps 44 and 46. When both the suction pumps 44 and 46 are driven, the control valves 45 and 47 are opened. When either one of the suction pumps 44 and 46 is driven, the control valve on the driving side is opened and the side not driven is closed. By allowing each of the suction pumps 44 and 46 and the control valves 45 and 47 to be individually driven and controlled, the setting range of the polishing liquid supply amount is expanded, and even if trouble occurs in one system, The other system can be used, and the reliability is further improved.

  As described above, in the prior art, the mixing ratio of each stock solution and the total flow rate of the mixed stock solution are likely to vary. Further, in the configuration using the orifice, the orifice inner diameter is about φ1.0 mm on the abrasive grain side, and on the additive solution side is about 1/5 (φ0.2 mm), and the diameter is extremely small. There is a risk of causing a reduction in diameter and blockage. Even in the constant flow valve, the same phenomenon may occur due to the configuration of the minute gap. With such a configuration, it may not be possible to accurately supply the slurry having a specific mixing ratio suitable for the desired processing.

  On the other hand, in the polishing liquid supply apparatus of the present invention, a tubular body communicating with each of the stock solutions 2, 4, 6 maintained at a constant liquid level in the collecting portion 33 and the plurality of stock solution tanks 1, 3, 5 is provided. The mixing ratio of the plurality of stock solutions can be set and changed by changing the number of 27, 29, and 31. The supply amount of the polishing liquid can be arbitrarily set and adjusted by controlling the capacity of the suction pump 39. be able to. Further, since the flow rate is set using the tubular bodies 27, 29, and 31 having an inner diameter of, for example, 2 mm to 3 mm, it is not necessary to use an orifice having a small hole diameter, and there is no occurrence of blockage due to abrasive grains or foreign matter or flow rate variation. Further, there is no storage or retention portion of the polishing liquid in which the stock solutions 2, 4, and 6 are mixed, and the polishing liquid can be stably supplied to the polishing apparatus without causing aggregation or sedimentation of the abrasive grains.

  As described above, according to the polishing liquid supply apparatus of the present invention, the accuracy of the mixing ratio and the supply amount of a plurality of stock solutions for polishing liquid is stabilized, and the polishing apparatus for polishing liquid with stable quality without deterioration is achieved. Supply, simplification of the apparatus, and improvement of reliability can be achieved.

(Embodiment 2)
A polishing liquid supply apparatus according to Embodiment 2 of the present invention will be described with reference to FIG. In FIG. 7, the same numbers as those in FIGS. In particular, the difference from FIGS. 1 to 6 is provided with a plurality of collecting portions 33 and 54 for merging a plurality of stock solutions 2, 4 and 6 having different components, and one end of each of the plurality of collecting portions 33 and 54 is connected to the plurality of collecting portions 33 and 54. Tubular bodies 27, 29, 31 and 48 having a certain length opened in the respective stock solutions 2, 4, 6 in the stock solution tanks 1, 3, 5 and having the other ends opened in the collecting portions 33 and 54, 50, 52 are provided, and the number of tubular bodies communicating with each of the collecting portions 33, 54 and each of the stock solutions 2, 4, 6 is different, and the mixing ratio of the plurality of stock solutions is set. The polishing liquid can be discharged to the discharge lines 36 and 55 of a plurality of systems. Further, control valves 49, 51, 53 are provided in the middle of the tubular bodies 48, 50, 52, and control valves 56, 61 and a suction pump 58 as discharge means are provided on the discharge line 55. The tip of the discharge line 55 has a discharge port 59 facing the polishing apparatus 60. The basic operation and action are the same as in the first embodiment.

  As a result, the polishing liquid can be supplied from a single group of stock solution tanks 1, 3, and 5 in parallel to a plurality of polishing apparatuses, and the apparatus can be greatly simplified and occupied space can be reduced.

  Further, in the plural lines of discharge lines 36 and 55, the plural lines of discharge lines 36 and 55 are made different from each other in the number of tubular bodies communicating with each of the collecting portions 33 and 54 and each of the stock solutions 2, 4 and 6. The mixing ratio of the polishing liquid discharged to 55 can be changed and set. Furthermore, the suction capacities of the suction pumps 39 and 58, which are discharge means, can be set individually, the discharge amount can be changed and the polishing liquid can be supplied to each of the polishing apparatuses 41 and 60, and the discharge lines 36 and 55 of a plurality of systems can be supplied. Since the polishing liquid can be discharged at the same time or only one of the polishing liquids, it is possible to respond finely to the requirements such as the mixing ratio and the discharge amount of the polishing apparatuses 41 and 60.

  Furthermore, it is also possible to add stock solutions having different components, select a stock solution including this, and supply the polishing solution to a plurality of discharge lines. In the present embodiment, the two discharge lines have been described. However, the present invention is not limited to this, and the present invention can be expanded to those having a plurality of discharge lines.

  The present invention can also be applied to a wide range of apparatus uses for supplying liquids having different components.

Configuration diagram of polishing liquid supply apparatus in Embodiment 1 of the present invention Expanded configuration diagram of the same assembly AA sectional view in FIG. The other block diagram of the polishing liquid supply apparatus in Embodiment 1 of this invention The other block diagram of the polishing liquid supply apparatus in Embodiment 1 of this invention The other block diagram of the polishing liquid supply apparatus in Embodiment 1 of this invention Configuration diagram of polishing liquid supply apparatus in Embodiment 2 of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stock solution tank 2 Stock solution 3 Stock solution tank 4 Stock solution 5 Stock solution tank 6 Stock solution 7 Replenishment tank 8 Pump 9 Circulation path 10 Supply pipe 11 Control valve 12 Discharge pipe 13 Replenishment tank 14 Pump 15 Circulation path 16 Supply pipe 17 Control valve 18 Discharge pipe 19 Supply pipe 20 Control valve 21 Load cell (weight detection means)
DESCRIPTION OF SYMBOLS 22 Liquid level sensor 23 Liquid level sensor 24 Pure water supply pipe 25 Control valve 26 Stirring means 27 Tubular body 28 Control valve 29 Tubular body 30 Control valve 31 Tubular body 32 Control valve 33 Collecting part 34 Control valve 35 Pure water supply pipe 36 Discharge Line 37 Control valve 38 Drain pipe 39 Suction pump (discharge means)
40 Discharge port 41 Polishing device 42 Control unit 43 Suction pump (discharge means)
44 Suction pump (discharge means)
45 Control valve 46 Suction pump (discharge unit)
47 Control Valve 48 Tubular Body 49 Control Valve 50 Tubular Body 51 Control Valve 52 Tubular Body 53 Control Valve 54 Collecting Portion 55 Discharge Line 56 Control Valve 57 Discharge Pipe 58 Suction Pump (Discharge Unit)
59 Discharge port 60 Polishing device

Claims (7)

A plurality of stock solution tanks each storing a plurality of stock solutions having different components, a collecting unit for joining the plurality of stock solutions, one end opened into each stock solution in the plurality of stock solution tanks, and the other end of the collecting unit And a discharge means for discharging the plurality of stock solutions to a polishing apparatus via the tubular body, the collection portion, and a discharge line, and the collection portion and the plurality of stock solution tanks. A polishing liquid supply apparatus, wherein the number of tubular bodies communicating with each stock solution is different to set the mixing ratio of the plurality of stock solutions. The polishing liquid supply apparatus according to claim 1, comprising tubular bodies having different cross-sectional areas or tubular bodies having different lengths. The polishing liquid according to claim 1 or 2, wherein a tube body of a small number of undiluted solutions is opened at a central portion of a gathering portion having a circular cross section, and a tube body of a undiluted solution is arranged outside and opened. Feeding device. The polishing liquid supply apparatus according to any one of claims 1 to 3, further comprising a control valve for opening and closing a passage of the tubular body. A plurality of collecting portions for concentrating a plurality of stock solutions having different components are provided, and for each of the plurality of collecting portions, one end is opened in each stock solution in the plurality of stock solution tanks, and the other end is opened in the collecting portion. The polishing liquid supply apparatus according to any one of claims 1 to 4, wherein a tubular body having a length of 1 mm is provided, and the polishing liquid can be discharged to a plurality of discharge lines. 6. The polishing liquid supply apparatus according to claim 5, wherein, among the discharges of the polishing liquid to a plurality of discharge lines, the mixing ratio or discharge amount of the polishing liquid to at least one discharge line is changed. Any one of the plurality of stock solutions is pure water, and only the pure water is used for a certain period of time before starting the discharge of the plurality of stock solutions to the collecting portion or for a certain time after stopping the discharging of the plurality of stock solutions to the collecting portion. The polishing liquid supply apparatus according to any one of claims 1 to 6, wherein the polishing liquid supply apparatus is made to discharge to the collecting portion.

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