Accurate control system for CMP (chemical mechanical polishing) temperature and pH (potential of hydrogen) value

Abstract

The invention provides a CMP polishing temperature and pH value accurate regulation and control system, and relates to the technical field of polishing systems. Comprising a polishing solution container, a buffer solution supply device, a cooling medium supply device, a pH value monitoring device, a temperature monitoring device, a stirring device, a first valve, a second valve, a cooling coil and a control device. According to the scheme, the temperature and the pH value of the polishing solution in the chemical mechanical polishing process can be accurately controlled, the efficiency and the quality of substrate production can be improved, the manufacturing cost can be reduced, and the market competitiveness of products can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of polishing equipment, and in particular to a method for accurately controlling CMP polishing temperature and pH value. Background Art

[0002] In the semiconductor industry, the performance advantages and continuous expansion of the wide range of applications of chips have placed extremely high demands on the quality control of their manufacturing process. High-performance chips have faster processing speeds, lower energy consumption, and higher integration, which have made them widely used in many fields such as smartphones, computers, automotive electronics, and medical equipment. With the advancement of technology, the application areas of chips are also constantly expanding to emerging technology fields such as artificial intelligence, big data processing, and the Internet of Things.

[0003] The core component of the chip, the substrate, plays the role of a carrier of circuit graphics, and its quality is directly related to the overall performance and reliability of the chip. In the chip manufacturing process, chemical mechanical polishing (CMP) technology is a key step in achieving substrate flatness. Its purpose is to remove irregular substances and excess materials on the substrate surface and provide a flat and smooth surface for subsequent wafer manufacturing. Controlling the temperature and pH value of the polishing liquid is a key factor in ensuring the high quality, high efficiency and repeatability of this process.

[0004] Precise control of temperature and pH value has a decisive influence on the chemical reaction rate and physical grinding during the polishing process. Too high or too low temperature will cause the chemical reaction rate to be out of control, which will affect the uniformity and rate of material removal. pH control is crucial to regulating the activity of chemicals in the polishing liquid. The appropriate pH value can optimize the corrosiveness of the polishing liquid and the activity of the abrasive, thereby improving the polishing efficiency and substrate surface quality. Improper temperature and pH control may cause scratches, pits and other microscopic damage to the substrate surface. In order to improve the surface uniformity of the substrate, reduce defects in the production process, and ensure product performance and reliability. However, in the existing CMP process, the control accuracy of temperature and pH value is low, which greatly affects the production efficiency and quality of the substrate. Summary of the invention

[0005] The invention discloses a precise control system for CMP polishing temperature and pH value, which can monitor and precisely control the temperature and pH value of the polishing liquid in real time, ensure the consistency of the product, and reduce the need for manual intervention and operation.

[0006] The present invention specifically adopts the following scheme: A precise control system for CMP polishing temperature and pH value, comprising: a polishing liquid container, a buffer solution supply device, a cooling medium supply device, a pH value monitoring device, a temperature monitoring device, a stirring device, a first valve, a second valve, a cooling coil and a control device; wherein the cooling coil is arranged in the polishing liquid container, the water inlet of the cooling coil is connected to the cooling medium supply device, and the water outlet thereof is connected to the first valve, the first valve is connected to the cooling medium supply device to circulate the cooling medium; the first valve is used to control the flow rate of the cooling medium supplied to the cooling coil by the cooling medium supply device, thereby controlling the temperature in the polishing liquid container; The buffer solution supply device is connected to the polishing liquid container through the second valve to supply new buffer solution to the polishing liquid container and adjust the pH value in the polishing liquid container; The stirring device is arranged in the polishing liquid container to stir the buffer solution in the polishing liquid container when the cooling medium supply device supplies the cooling medium to the cooling coil or when the buffer solution supply device supplies the buffer solution into the polishing liquid container, so as to improve the temperature uniformity or pH uniformity of the buffer solution in the polishing liquid container; The polishing liquid container is provided with a pH value monitoring device and a temperature monitoring device connected to the control device, wherein the pH value monitoring device is suitable for detecting the pH value data in the polishing liquid container and transmitting the pH value data to the control device; the temperature monitoring device is suitable for real-time monitoring the temperature in the polishing liquid container and transmitting the temperature data to the control device; The control device is connected to the first valve, the second valve and the stirring device, and is configured to control the second valve to open and the stirring device to start to regulate the pH value in the polishing liquid container when it is detected that the pH value data in the polishing liquid container exceeds a preset value range; and to control the first valve to open and the stirring device to start to regulate the temperature in the polishing liquid container when it is detected that the temperature in the polishing liquid container is higher than a preset value.

[0007] Furthermore, the cooling medium supply device is suitable for supplying cooling water into the cooling coil to perform heat exchange on the buffer solution in the polishing liquid container, thereby reducing the temperature in the polishing liquid container.

[0008] Furthermore, the pH value monitoring device is a plurality of pH value sensors distributed on the inner wall of the polishing liquid container, and the temperature monitoring device is a plurality of temperature sensors distributed on the inner wall of the polishing liquid container.

[0009] Furthermore, the pH monitoring device is suitable for real-time monitoring of the pH value in the polishing liquid container, and real-time feedback to the control device to detect the change of pH value in real time, and the supply amount of buffer solution is adjusted accordingly by the control device to maintain the pH value within the target range.

[0010] Furthermore, the stirring device includes a stirrer and a stirring controller, and the stirring controller is connected to the control device and is suitable for driving the stirrer to rotate under the control of the control device.

[0011] Beneficial effects: The present invention uses a temperature sensor and a pH sensor to detect the actual temperature and pH value of the polishing liquid respectively, and transmits the detected signals to the control device. The control device compares the current temperature value and pH value measured by the sensor with the set value, and controls the operation of the corresponding adjustment device according to the comparison result to adjust the temperature and pH value. At the same time, the above two sensors will continuously detect the corresponding data, and continuously adjust according to the difference between the actual value measured by the sensor and the set value, so that the actual value tends to the set value, so as to maintain a stable working state of the system.

[0012] After the regulating device of the present invention is put into use, it can monitor the temperature and pH value of the polishing liquid in real time and adjust it automatically, and can ensure that the product is always within the appropriate temperature and pH value range during the production process. The pH value is adjusted by continuing to introduce a buffer solution (i.e., polishing liquid) into the polishing liquid barrel, which will not cause major changes in the components in the polishing liquid barrel and affect the purity and performance of the polishing liquid. The quality and consistency of the product can be optimized, while reducing the need for manual intervention and operation, thereby improving the efficiency and reliability of the production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The present invention is a schematic diagram of a system for accurately controlling CMP polishing temperature and pH value according to an embodiment of the present invention.

[0014] Figure numerals: 1. polishing liquid container, 2. temperature monitoring device, 3. control device, 4. first valve, 5. cooling medium supply device, 6. cooling coil, 7. pH value monitoring device, 8. second valve, 9. buffer solution supply device, 10. stirring controller, 11. agitator. DETAILED DESCRIPTION

[0015] Combination Figure 1 This embodiment provides a precise control system for CMP polishing temperature and pH value, including: a polishing liquid container 1, a buffer solution supply device 9, a cooling medium supply device 5, a pH value monitoring device 7, a temperature monitoring device 2, a stirring device, a first valve 4, a second valve 8, a cooling coil 6 and a control device 3; wherein, The cooling coil 6 is arranged in the polishing liquid container 1, the water inlet of the cooling coil 6 is connected to the cooling medium supply device 5, and the water outlet thereof is connected to the first valve 4, the first valve 4 is connected to the cooling medium supply device 5 to circulate the cooling medium; the first valve 4 is used to control the flow rate of the cooling medium supplied to the cooling coil 6 by the cooling medium supply device 5, thereby controlling the temperature in the polishing liquid container 1; The buffer solution supply device 9 is connected to the polishing liquid container 1 through the second valve 8 to supply new buffer solution to the polishing liquid container 1 and adjust the pH value in the polishing liquid container 1; The stirring device is arranged in the polishing liquid container 1 to stir the buffer solution in the polishing liquid container 1 when the cooling medium supply device 5 supplies the cooling medium to the cooling coil 6 or when the buffer solution supply device 9 supplies the buffer solution to the polishing liquid container 1, so as to improve the temperature uniformity or pH uniformity of the buffer solution in the polishing liquid container 1; The polishing liquid container 1 is provided with a pH value monitoring device 7 and a temperature monitoring device 2 connected to the control device 3, wherein the pH value monitoring device 7 is suitable for detecting the pH value data in the polishing liquid container 1 and transmitting the pH value data to the control device 3; the temperature monitoring device 2 is suitable for real-time monitoring of the temperature in the polishing liquid container 1 and transmitting the temperature data to the control device 3; The control device 3 is connected to the first valve 4, the second valve 8 and the stirring device, and is configured to control the second valve 8 to open and the stirring device to start to regulate the pH value in the polishing liquid container 1 when it is detected that the pH value data in the polishing liquid container 1 exceeds a preset value range; and to control the first valve 4 to open and the stirring device to start to regulate the temperature in the polishing liquid container 1 when it is detected that the temperature in the polishing liquid container 1 is higher than a preset value.

[0016] In this embodiment, the polishing liquid container 1 can be a polishing liquid barrel, which is used to contain a buffer solution for polishing and is connected to the polishing device. In order to control the temperature and pH value in the polishing liquid barrel, a temperature control system and a pH value control system are provided in this embodiment. Specifically, the temperature control system includes a cooling medium supply device 5 and a cooling coil 6 arranged in the polishing liquid barrel. A plurality of temperature sensors are arranged in the polishing liquid container 1, and the temperature sensors are connected to the control device 3 to feed back the temperature data to the control device 3 in real time for comparison processing. The cooling medium supply device 5 is connected to the water inlet of the cooling coil 6 to be suitable for supplying cooling water to the cooling coil 6, thereby performing heat exchange on the buffer solution in the polishing liquid container 1 and reducing the temperature in the polishing liquid container 1. The outlet of the cooling coil 6 is connected to the first valve 4, and the first valve 4 is connected to the cooling medium supply device 5 to circulate the cooling medium; the first valve 4 is used to control the amount of cooling medium supplied to the cooling coil 6 by the cooling medium supply device 5, thereby controlling the temperature in the polishing liquid container 1; the control device 3 is connected to the first valve 4 to control the opening of the first valve 4, thereby controlling the circulation speed of the cooling liquid in the cooling coil 6 to control the temperature. The first valve 4 can be a solenoid valve, and the opening can be controlled by the control device 3. When working, the temperature sensor on the inner wall of the polishing liquid barrel starts to monitor the temperature of the polishing liquid (i.e., the buffer solution) when the CMP system is started. After receiving the temperature signal, the control device 3 compares it with the set temperature range to determine whether it is within the set temperature range. When the polishing liquid temperature is within the normal working range, the output device of the control device 3 does not work; when the temperature of the polishing liquid exceeds the set temperature, the control device 3 controls the first valve 4 to open, and controls the cooling water to circulate in the cooling coil 6. When the temperature returns to the normal range, the control device 3 outputs a signal to close the first valve 4, and the first valve 4 performs an action to prohibit the cooling water from working in the cooling coil 6. When the first valve 4 is opened, the control device 3 simultaneously controls the stirring device to stir the polishing liquid, so as to accelerate the uniformization of the temperature in the polishing liquid barrel.

[0017] The pH value control system includes the buffer solution supply device 9 and a plurality of pH sensors distributed on the inner wall of the polishing liquid container 1. The pH sensor is suitable for real-time monitoring of the pH value in the polishing liquid container 1, and real-time feedback to the control device 3 to detect the change of the pH value in real time, and the control device 3 adjusts the supply amount of the buffer solution accordingly to maintain the pH value within the target range.

[0018] The buffer solution supply device 9 is connected to the polishing liquid container 1 through the second valve 8 to supply new buffer solution to the polishing liquid container 1, thereby adjusting the pH value in the polishing liquid container 1; when the control device 3 detects that the pH value is lower than or exceeds the preset range value, it controls the opening of the second valve 8 and controls the stirring device to start stirring, so that the new buffer solution is quickly mixed with the original buffer solution, thereby controlling the pH value. When the second valve 8 starts to work, the buffer solution supply device 9 supplies buffer solution to the polishing liquid barrel, and the pH value of the polishing liquid near the supply port will change rapidly. The second valve 8 and the stirrer 11 work at the same time, which can promote the rapid mixing of the reactants in the solution, improve the reaction speed and efficiency, thereby achieving faster pH value adjustment, and ensuring the uniformity of the pH value in the entire system. Here, when adjusting the pH value, it is necessary to slowly inject a new buffer solution into the polishing liquid container 1, and the amount injected each time needs to be controlled to prevent too much buffer solution from being injected at one time. The second valve 8 described in this embodiment also uses an existing solenoid valve, which can be controlled by the control device 3.

[0019] The stirring device includes a stirrer 11 and a stirring controller 10, and the stirring controller 10 is connected to the control device 3 and is suitable for driving the stirrer 11 to rotate under the control of the control device 3. Here, the temperature control system and the pH value control system are independent of each other and share the same stirring device. The temperature control system and the pH value control system can be operated independently or simultaneously.

[0020] The control device 3 can adopt an existing equipment control system, such as an industrial computer system, etc., which can receive data monitored by the sensor and perform data analysis, and can also control the opening and closing of the first valve 4, the second valve 8 and the stirring device according to the set program. In this embodiment, the control device 3 compares the actual value of the temperature and pH value measured by the sensor with the set value. When the actual value is within the normal working range, the control device 3 does not act. When the actual value exceeds the threshold, the control device 3 outputs a control signal to control the opening and closing of the valve, so that cooling water flows through the cooling coil 6 to reduce the temperature, or automatically adds a buffer solution to adjust the pH value of the polishing liquid.

[0021] It should be noted that the buffer solution supply device 9 and the cooling medium supply device 5 mentioned in this embodiment are both existing technology products and will not be described in detail here.

[0022] Through the scheme of the present invention, the temperature and pH value of the polishing liquid can be monitored in real time and automatically adjusted, and it can be ensured that the product is always within the appropriate temperature and pH range during the production process, thereby optimizing the quality and consistency of the product, while reducing the need for manual intervention and operation, and improving the efficiency and reliability of the production process.

[0023] It should be understood that the above are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention.

[0024] The above description of the drawings used in the implementation manner only illustrates certain embodiments of the present invention and should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

Claims

1. A precise control system for CMP polishing temperature and pH value, characterized in that: include: polishing liquid container, buffer solution supply device, cooling medium supply device, pH value monitoring device, temperature monitoring device, stirring device, first valve, second valve, cooling coil and control device; wherein, The cooling coil is arranged in the polishing liquid container, the water inlet of the cooling coil is connected to the cooling medium supply device, and the water outlet thereof is connected to the first valve, the first valve is connected to the cooling medium supply device to circulate the cooling medium; the first valve is used to control the flow rate of the cooling medium supplied to the cooling coil by the cooling medium supply device, thereby controlling the temperature in the polishing liquid container; The buffer solution supply device is connected to the polishing liquid container through the second valve to supply new buffer solution to the polishing liquid container and adjust the pH value in the polishing liquid container; The stirring device is arranged in the polishing liquid container to stir the buffer solution in the polishing liquid container when the cooling medium supply device supplies the cooling medium to the cooling coil and / or when the buffer solution supply device supplies the buffer solution into the polishing liquid container, so as to improve the temperature uniformity or pH uniformity of the buffer solution in the polishing liquid container; The polishing liquid container is provided with a pH value monitoring device and a temperature monitoring device connected to the control device, wherein the pH value monitoring device is suitable for detecting the pH value data in the polishing liquid container and transmitting the pH value data to the control device; the temperature monitoring device is suitable for real-time monitoring the temperature in the polishing liquid container and transmitting the temperature data to the control device; The control device is connected to the first valve, the second valve and the stirring device, and is configured to control the second valve to open and the stirring device to start to regulate the pH value in the polishing liquid container when it is detected that the pH value data in the polishing liquid container exceeds a preset value range; and to control the first valve to open and the stirring device to start to regulate the temperature in the polishing liquid container when it is detected that the temperature in the polishing liquid container is higher than a preset value.

2. The precise control system of CMP polishing temperature and pH value according to claim 1, characterized in that: The cooling medium supply device is suitable for supplying cooling water into the cooling coil to perform heat exchange on the buffer solution in the polishing liquid container, thereby reducing the temperature in the polishing liquid container.

3. The precise control system of CMP polishing temperature and pH value according to claim 1, characterized in that: The pH value monitoring device is a plurality of pH value sensors distributed on the inner wall of the polishing liquid container, and the temperature monitoring device is a plurality of temperature sensors distributed on the inner wall of the polishing liquid container.

4. The precise control system of CMP polishing temperature and pH value according to claim 1, characterized in that: The pH monitoring device is suitable for real-time monitoring of the pH value in the polishing liquid container, and real-time feedback to the control device to detect the change of pH value in real time, and the supply amount of buffer solution is adjusted accordingly by the control device to maintain the pH value within the target range.

5. The precise control system of CMP polishing temperature and pH value according to claim 1, characterized in that: The stirring device comprises a stirrer and a stirring controller, wherein the stirring controller is connected to the control device and is suitable for driving the stirrer to rotate under the control of the control device.

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