阅读说明：本技术 研磨液再生回收系统 (Grinding fluid regeneration and recovery system ) 是由 郑圣弘 宋凯 吴思韵 于 2020-06-29 设计创作，主要内容包括：本发明涉及化学机械抛光技术领域,具体涉及一种研磨液再生回收系统,包括废液收集桶、循环储存桶、膜过滤装置、渗透桶槽、若干添加剂桶槽以及控制器,所述废液收集与循环储存桶连通,所述循环储存桶与膜过滤装置构成浓缩回路,所述膜过滤装置的渗透端固定连接有循环管道,所述循环管道上设置有渗透桶槽以及反清洗泵,所述循环储存桶上还设置有输出管道,所述输出管道上还设置有输出泵,所述反清洗泵、输出泵均与所述控制器电连接。所述研磨液再生回收系统回收工艺简单可靠,可实现研磨液的回收利用,有效降低CMP过程的加工成本,且优化排废,减低环保的负担。(The invention relates to the technical field of chemical mechanical polishing, in particular to a grinding fluid regeneration and recovery system which comprises a waste liquid collecting barrel, a circulating storage barrel, a membrane filtering device, a permeation barrel groove, a plurality of additive barrel grooves and a controller, wherein the waste liquid collecting barrel is communicated with the circulating storage barrel, the circulating storage barrel and the membrane filtering device form a concentration loop, a permeation end of the membrane filtering device is fixedly connected with a circulating pipeline, the circulating pipeline is provided with the permeation barrel groove and a backwashing pump, the circulating storage barrel is also provided with an output pipeline, the output pipeline is also provided with an output pump, and the backwashing pump and the output pump are both electrically connected with the controller. The recovery process of the grinding fluid regeneration recovery system is simple and reliable, the grinding fluid can be recycled, the processing cost in the CMP process is effectively reduced, waste discharge is optimized, and the burden of environmental protection is reduced.)

1. A grinding fluid regeneration recovery system is characterized in that: comprises a waste liquid collecting barrel (10), a circulating storage barrel (30), a membrane filtering device (50), a permeation barrel groove (601), a plurality of additive barrel grooves (801) and a controller, wherein the waste liquid collecting barrel (10) is communicated with the water inlet end of the circulating storage barrel (30) through a first conveying pipeline (20), the return end of the circulating storage barrel (30) is communicated with the water inlet end of the membrane filtering device (50) through a second conveying pipeline (40a), the return end of the membrane filtering device (50) is communicated with the water return end of the circulating storage barrel (30) through a third conveying pipeline (40b), the permeation end of the membrane filtering device (50) is fixedly connected with a circulating pipeline (60), the circulating pipeline (60) is provided with the permeation barrel groove (601) and a reverse cleaning pump (602), the circulating storage barrel (30) is further provided with an output pipeline (70), be provided with output pump (701) on output pipeline (70), additive tank (801) respectively through different infusion pipeline (80) with circulation storage bucket (30) intercommunication, all be provided with additive pump (802) on infusion pipeline (80), additive pump (802) all with the controller electricity is connected, anti-scavenging pump (602), additive pump (802), output pump (701) all with the controller electricity is connected.

2. The slurry reclamation recovery system as recited in claim 1, wherein: the second conveying pipeline (40a) is provided with a pressure pump (401), a pressure sensor (402) is arranged in the second conveying pipeline (40a), and the pressure pump (401) and the pressure sensor (402) are electrically connected with the controller.

3. The slurry reclamation recovery system as recited in claim 1, wherein: a coarse filtering device (22) and a first filtering device (23) are arranged on the first liquid conveying pipeline (80), and the coarse filtering device (22) is arranged at the upstream of the first filtering device (23).

4. The slurry reclamation recovery system as recited in claim 1, wherein: the output pipeline (70) is provided with at least two second filtering devices (702) with different filtering precisions.

5. The slurry reclamation recovery system as recited in claim 1, wherein: a plurality of solution data acquisition sensors are arranged in the circulating storage barrel (30).

6. The slurry reclamation recovery system as recited in claim 5, wherein: the solution data acquisition sensor at least comprises one or more of a liquid level sensor, a turbidity sensor and a temperature sensor.

7. The slurry reclamation recovery system as recited in claim 1, wherein: the inside of the circulating storage barrel (30) is also provided with a stirring device.

8. The slurry reclamation recovery system as recited in claim 1, wherein: the waste liquid collecting barrel (10), the circulating storage barrel (30) and the additive barrel groove (801) are all of a closed structure, and the waste liquid collecting barrel (10), the circulating storage barrel (30) and the additive barrel groove (801) are all communicated with the nitrogen conveying pipeline (90).

9. The slurry reclamation recovery system as recited in claim 1, wherein: still be provided with fourth pipeline (100) on infiltration bucket groove (601), infiltration bucket groove (601) has dosing tank (100a) through fourth pipeline (100) intercommunication, just the inside of dosing tank (100a) is provided with the magnetic field.

10. The slurry reclamation recovery system as recited in claim 9, wherein: the dosing tank (100a) is fixedly connected with a dosing pipeline, the dosing tank (100a) is communicated with a liquid medicine barrel groove (11) through the dosing pipeline, and a dosing pump (12) is arranged on the dosing pipeline.

Technical Field

The invention relates to the technical field of chemical mechanical polishing, in particular to a grinding fluid regeneration and recovery system.

Background

Chemical mechanical polishing is by far the only surface finishing technique that can provide global planarization and has been widely used for planarization of surfaces of integrated circuit chips, computer rigid disks, micro-mechanical systems, and the like. As the size of the machined workpiece is getting larger and the machining precision is gradually improved, chemical mechanical polishing, as a technique suitable for this requirement, has now developed into an inevitable choice in the polishing process.

With the rapid development of communication networks and the like, the demand for Integrated Circuits (ICs) is increasing, and the development of ICs is continuously moving toward high speed, high integration, high density and high performance. On one hand, in chip manufacturing, in order to reduce production cost, the size of a silicon wafer is gradually increased; on the other hand, in order to improve the integration of ICs, the scribe line width is continuously reduced. The requirements for planarization of silicon wafer surfaces are becoming more stringent, and the requirements for material removal rate, surface roughness, and surface/subsurface non-damage during polishing are increasing, and Chemical Mechanical Polishing (CMP) is widely used in IC manufacturing as a currently recognized global planarization technology. In the conventional CMP, the polishing solution as a consumable material accounts for about 40% of the total cost of the CMP process, but the utilization rate thereof can only reach 20%, and therefore, the cost of the CMP process depends on the cost of consumables, especially the cost of the polishing solution. Therefore, excessive use of the polishing solution not only causes high manufacturing cost of the IC, but also generates a large amount of waste polishing solution to pollute the surrounding environment.

80% of the polishing solution is not degraded in the CMP process, and in the polishing process, because a large amount of deionized water is used for cleaning the wafer, the abrasive concentration of the polishing solution is reduced, and the same polishing quality cannot be obtained by using the polishing solution again for polishing. Meanwhile, the large amount of grinding waste liquid generated during the chemical mechanical polishing process means a considerable cost for wastewater treatment. Therefore, the used grinding fluid is recycled and has great practical value.

Disclosure of Invention

In order to solve the above technical problems, an object of the present invention is to provide a recycling system for recycling polishing slurry, which has a simple and reliable recycling process, can achieve recycling of the polishing slurry, effectively reduce the processing cost of the CMP process, optimize waste discharge, and reduce the burden of environmental protection.

In order to achieve the technical effect, the invention adopts the following technical scheme:

a grinding fluid regeneration and recovery system comprises a waste liquid collecting barrel, a circulating storage barrel, a membrane filtering device, a permeation barrel groove, a plurality of additive barrel grooves and a controller, wherein the waste liquid collecting barrel is communicated with a water inlet end of the circulating storage barrel through a first conveying pipeline, a backflow end of the circulating storage barrel is communicated with a water inlet end of the membrane filtering device through a second conveying pipeline, a backflow end of the membrane filtering device is communicated with a water return end of the circulating storage barrel through a third conveying pipeline, a circulating pipeline is fixedly connected with the permeation end of the membrane filtering device, the circulating pipeline is provided with the permeation barrel groove and a reverse cleaning pump, the circulating storage barrel is further provided with an output pipeline, the output pipeline is provided with an output pump, the additive barrel grooves are respectively communicated with the circulating storage barrel through different infusion pipelines, and the infusion pipelines are respectively provided with the additive pump, the additive pump is electrically connected with the controller, and the backwashing pump, the additive pump and the output pump are electrically connected with the controller.

Further, a pressure pump is arranged on the second conveying pipeline, a pressure sensor is arranged in the second conveying pipeline, and the pressure pump and the pressure sensor are electrically connected with the controller.

Further, be provided with coarse filter equipment and first filter equipment on the first infusion pipeline, just coarse filter equipment sets up first filter equipment's upstream.

Furthermore, at least two second filtering devices with different filtering precisions are arranged on the output pipeline

Furthermore, a plurality of solution data acquisition sensors are arranged in the circulating storage barrel.

Further, the solution data acquisition sensor at least comprises one or more of a liquid level sensor, a turbidity sensor, a temperature sensor and an LISA optical water quality sensor.

Further, the inside of circulation storage bucket still is provided with agitating unit.

Further, the waste liquid collecting barrel, the circulating storage barrel and the additive barrel groove are of an airtight structure, and the waste liquid collecting barrel, the circulating storage barrel and the additive barrel groove are communicated with the nitrogen conveying pipeline.

Further, still be provided with the fourth pipeline on the infiltration bucket groove, the infiltration bucket groove has the dosing pond through fourth pipeline intercommunication, just the inside in dosing pond is provided with the magnetic field.

Further, the dosing tank is fixedly connected with a dosing pipeline, the dosing tank is communicated with a liquid medicine barrel groove through the dosing pipeline, and a dosing pump is arranged on the dosing pipeline.

Further, the controller is a PLC controller.

Compared with the prior art, the grinding fluid regeneration and recovery system provided by the invention has the beneficial effects that: according to the grinding fluid regeneration and recovery system, the grinding waste fluid is collected and purified, so that the grinding materials in the grinding waste fluid can be effectively concentrated and recovered, the recovered grinding fluid is regenerated by adding additives so as to be convenient to recycle, the grinding fluid can be effectively recycled, the grinding cost is reduced, and the generation of the waste fluid in the chemical mechanical polishing process is reduced; meanwhile, the penetrating fluid is reprocessed by the magnetic separation technology, so that the generation of waste liquid and the post-treatment cost of the waste liquid can be effectively reduced, and the method has remarkable economic and environmental benefits.

Drawings

FIG. 1 is a schematic diagram illustrating an overall structure of a polishing slurry recycling system according to an embodiment of the present invention;

the reference signs are: 10-a waste liquid collecting barrel, 11-a liquid medicine barrel tank, 12-a dosing pump, 20-a first conveying pipeline, 21-a conveying pump, 22-a rough filtering device, 23-a first filtering device, 30-a circulating storage barrel, 40 a-a second conveying pipeline, 40 b-a third conveying pipeline, 401-a pressure pump, 402-a pressure sensor, 50-a membrane filtering device, 60-a circulating pipeline, 601-a permeation barrel tank, 602-a backwashing pump, 70-an output pipeline, 701-an output pump, 702-a second filtering device, 80-an infusion pipeline, 801-an additive barrel tank, 802-an additive pump, 90-a nitrogen conveying pipeline, 100-a fourth conveying pipeline and 100a dosing pool.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.

As shown in fig. 1, the polishing slurry recycling system provided in this embodiment includes a waste liquid collecting tank 10, a circulating storage tank 30, a membrane filtering device 50, a permeation tank 601, a plurality of additive tanks 801, and a PLC controller.

In this embodiment, the waste liquid collecting barrel 10 is used for collecting and storing waste liquid containing abrasive particles generated in a CMP process, the waste liquid collecting barrel 10 is communicated with the water inlet end of the circulation storage barrel 30 through a first conveying pipeline 20, and a conveying pump 21 is disposed on the first conveying pipeline 20, so as to convey the waste liquid in the waste liquid collecting barrel 10 to the circulation storage barrel 30 for waiting for treatment.

In this embodiment, be provided with coarse filter 22 and first filter equipment 23 on first pipeline 20, the coarse filtration form sets up before first filter equipment 23, the filter fineness of coarse filter 22 is preferably 80um-100um, coarse filter equipment 22 is preferably basket filter, is convenient for grind impurity with remaining large granule in the grinding waste water and carry out prefiltering, and this kind of filtration mode not only can protect the normal operating of follow-up equipment, and it is extremely convenient to maintain in the use, is convenient for carry out continuous and high-efficient processing to the waste liquid. The first filtering device 23 is a filter element type filter, and the filtering precision of the filter element type filter used in the first filtering device is preferably 15-30 um so as to further remove large-particle-size impurities in the grinding fluid.

In this embodiment, a membrane filtering device 50 is further disposed behind the recycling storage barrel 30, a water inlet end, a backflow end and a permeation end are disposed on the membrane filtering device 50, the backflow end of the recycling storage barrel 30 is communicated with the water inlet end of the membrane filtering device 50 through a second conveying pipeline 40a, and a pressure pump 401 is further disposed on the second conveying pipeline 40 a. The return end of the membrane filtering device 50 is communicated with the return end of the circulating storage barrel 30 through a third conveying pipeline 40b, and a concentration loop is formed between the circulating storage barrel 30 and the membrane filtering device 50. The permeation end of the membrane filtration device 50 is fixedly connected with a circulating pipeline 60, a permeation barrel tank 601 and a backwashing pump 602 are arranged on the circulating pipeline 60, and the backwashing pump 602 is electrically connected with the controller. When the grinding fluid is concentrated, the grinding fluid in the circulating storage barrel 30 is pumped to the membrane filtering device 50 through the second conveying pipeline 40a by the pressure pump 401, under the action of pressure, moisture in the grinding fluid permeates through the filtering membrane of the membrane filtering device 50 so as to achieve the purpose of concentrating the grinding fluid, the solution which does not permeate through the filtering membrane and contains abrasive particles flows back to the circulating storage barrel 30 through the backflow end, the third conveying pipeline 40b and the backflow end, and the solution permeating through the filtering membrane enters the permeation barrel groove 601 through the circulating pipeline 60.

In this embodiment, a pressure sensor 402 is disposed in the second delivery pipe 40a, preferably, the pressure sensor 402 is disposed at the water outlet end of the pressure pump 401, and the pressure sensors 402 are electrically connected to the PLC controller, the pressure sensor 402 is configured to measure the water pressure in the second delivery pipe 40a and upload the detected pressure value to the PLC controller, so as to reflect the blockage of the membrane filtration device 50 by the magnitude of the pressure value to determine the cleaning time, when the detected value of the pressure sensor 402 is smaller than the set threshold of the PLC controller, it indicates that the ultrafiltration rate is reduced due to the deposition of solute on the membrane surface, and the ultrafiltration rate needs to be backwashed to recover the ultrafiltration rate, at this time, the controller can backwash the membrane filtration device 50 by controlling the backwash pump 602 to pump the solution in the permeate tank 601 out, so as to ensure the continuous and efficient operation of the filtering membrane and improve the concentration treatment efficiency.

In this embodiment, a stirring device is disposed in the recycling storage barrel 30, and the stirring device is used to stir the solution in the recycling storage barrel 30, optionally, the stirring device is used to stir mechanically or by air flow, so as to uniformly disperse the solute in the recycling storage barrel 30.

In this embodiment, be provided with a plurality of solution data acquisition sensors in the circulation storage bucket 30, solution data acquisition sensor includes one or more in level sensor, turbidity sensor, temperature sensor and the LISA optics water quality sensor, level sensor is for throwing into formula level sensor, turbidity sensor is convenient for right the solution turbidity in the circulation storage bucket 30 detects. The circulating storage barrel 30 is further provided with an output pipeline 70, and the output pipeline 70 is further provided with an output pump 701. The solution data acquisition sensor and the output pump 701 are electrically connected with the controller, the solution data acquisition sensor is electrically connected with the controller, so that the solution state data in the circulating storage barrel 30 can be conveniently transmitted to the controller in real time, and when the controller judges that the output pump 701 is started at a proper discharging time according to the detection data of each solution data acquisition sensor.

In this embodiment, the polishing fluid recycling system further includes a plurality of additive tanks 801, the additive tanks 801 are respectively communicated with the circulation storage tank 30 through different infusion pipelines 80, the infusion pipelines 80 are respectively provided with additive pumps 802, the additive pumps 802 are electrically connected to the controller, and optionally, the additive may be a pH adjuster, a stabilizer, an abrasive, or the like.

In this embodiment, two second filtering devices 702 are continuously disposed on the output pipeline 70, the second filtering devices 702 are all core filters, and the filtering precision of the second filtering device 702 located upstream is greater than that of the second filtering device 702 located downstream, the filtering precision of the second filtering device 702 located upstream is preferably 5um to 10um, and the filtering precision of the second filtering device 702 located downstream is 1um to 5 um.

In this embodiment, the waste liquid collecting barrel 10, the circulating storage barrel 30 and the additive barrel groove 801 are all of a closed structure and are all communicated with the nitrogen conveying pipeline 90, so as to ensure that the polishing liquid recycling system works under a micro-positive pressure condition.

In this embodiment, a fourth delivery pipe 100 is further disposed on the permeation barrel tank 601, the permeation barrel tank 601 is communicated with a dosing tank 100a through the fourth delivery pipe 100, and a water flow stirring device and a magnetic field are disposed inside the dosing tank 100a, optionally, the magnetic field is provided by a permanent magnet. The dosing tank 100a is fixedly connected with a dosing pipeline, the dosing tank 100a is communicated with a liquid medicine barrel groove 11 through the dosing pipeline, and a dosing pump 12 is arranged on the dosing pipeline. The liquid medicine in the liquid medicine tank 11 at least includes a magnetic seed tank, such as a magnetite slurry tank, and preferably, the liquid medicine tank 11 further includes a pH regulator tank. Add the medicine pond 100a and adopt the magnetism separation technique, do through liquid medicine bucket groove 11 add medicine pond 100a and provide magnetic seed and other auxiliaries, through the rivers stirring for the magnetic seed and the auxiliary of adding and the waste liquid misce bene that adds in the medicine pond 100a to guarantee the abundant collision and the absorption of magnetic seed and impurity, subside the adsorbed impurity of magnetic seed through magnetic field, with the subsequent processing cost of reduction waste water.

The working principle of the grinding fluid regeneration and recovery system provided by the invention is as follows: grinding waste liquid generated in the chemical mechanical grinding process flows into a waste liquid collecting barrel 10 after being collected, and then is pumped into a circulating storage barrel 30 through a conveying pump 21, a rough filtering device 22 and a first filtering device 23, a pressure pump 401 is started to enable the grinding waste liquid in the storage barrel to continuously pass through a membrane filtering device 50 for concentration, concentrated liquid flows back into the circulating storage barrel 30 through a backflow end of the membrane filtering device 50, penetrating liquid of two membrane filtering devices 50 enters a penetrating barrel groove 601 through a circulating pipeline 60 and pumps the penetrating barrel groove 601 out through a backwashing pump 602 in the process of backwashing the membrane filtering device 50 so as to backwash the membrane filtering device 50, the filtering effect of the membrane filtering device 50 is maintained, and backwashing liquid reversely flows into the circulating storage barrel 30 through the backwashing pump 602 so as to ensure the efficient recovery of abrasive particles. The additive in the additive barrel groove 801 is pumped into a circulating system through an additive pump 802, so that the adjustment and correction of the concentration and the state of the grinding fluid are realized. Through observing turbidity sensor's testing data to the concentration of abrasive particle in the solution turbidity reaction solution, when abrasive particle's concentration reached the requirement, the PLC controller is through closing force (forcing) pump 401, opens output pump 701, and concentrated and the lapping liquid of correcting passes through second filter equipment 702 and accomplishes promptly to retrieve, can supply chemical mechanical polishing once more to utilize. The penetrating fluid in the penetrating barrel tank 601 is used for backwashing the membrane filtering device 50 and can enter the dosing tank 100a through the fourth conveying pipeline 100 for retreatment, the dosing tank 100a adopts a magnetic separation technology, the treatment cost is low, and impurities in the penetrating fluid can be effectively removed, so that the environmental burden is reduced.

Although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the invention as defined in the appended claims. The techniques, shapes, and configurations not described in detail in the present invention are all known techniques.