Temperature control system and method for process liquid and wet processing equipment

Abstract

The invention provides a temperature control system and method for process liquid and semiconductor wet processing equipment. The temperature control system comprises a constant-temperature water unit, a first temperature control unit and a second temperature control unit, a flow path of the process liquid sequentially flows through the first temperature control unit and the second temperature control unit, and a water outlet of the constant-temperature water unit is connected with inlets of heat exchange channels of the two temperature control units in parallel so as to achieve two-stage temperature adjustment of the process liquid. According to the technical scheme, coarse adjustment and fine adjustment control over the temperature of the process liquid is achieved mainly through a two-stage temperature control framework with the process liquid connected in series and the constant-temperature water connected in parallel, and the accuracy and stability of the temperature of the process liquid in the wet process can be guaranteed. Moreover, the temperature control operation is continuously carried out, and generally, the temperature control operation does not occupy extra process takt time, so that the operation efficiency of wet processing is not influenced.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing equipment technology, and more specifically, to a temperature control system, a temperature control method, and a semiconductor wet processing equipment for process liquids. Background Technology

[0002] With the development of China's semiconductor industry, the technological capabilities of major chip manufacturers are also continuously improving. To adapt to the ever-upgrading process nodes and the ever-increasing demand for production capacity, the control of various process parameters in semiconductor wet processing is gradually shifting towards higher precision and stability. Precise control of the process liquid temperature is currently one of the main areas of focus in the industry for addressing challenges such as narrow process windows and difficulties in improving yield.

[0003] Semiconductor wet processes, such as photoresist development and high-precision wet etching, are extremely sensitive to the temperature of the process liquid. Even slight fluctuations in the temperature of the process liquid can cause changes in the chemical reaction rate on the substrate surface, thereby directly affecting the development or etching rate and ultimately impacting the chip yield and performance.

[0004] Existing process liquid temperature control solutions typically employ a single-stage temperature regulation method. Generally, to ensure responsiveness, a section of water bath thermostat piping is installed near the process point. This approach often struggles to achieve high-precision temperature control when dealing with large temperature differences or flow fluctuations in the incoming process liquid, exhibiting slow response, susceptibility to overshoot, and poor stability. Excessive temperature fluctuations in the incoming process liquid can not only prevent the final temperature from stabilizing precisely at the set value but may also lead to deviations in the process results for the entire batch of wafers, and potentially cause more serious failures due to process window drift. Summary of the Invention

[0005] To address the issues of limited temperature control accuracy and poor stability in existing process liquid temperature control solutions, this application provides a process liquid temperature control system, a temperature control method, and a semiconductor wet processing equipment.

[0006] The technical solution of the present invention provides a temperature control system for a process liquid, including a constant temperature water unit, a first temperature control unit, and a second temperature control unit; the flow path of the process liquid is configured to flow through the first temperature control unit and the second temperature control unit in series; the outlet of the constant temperature water unit is connected in parallel with the inlet of the heat exchange channel of the first temperature control unit and the second temperature control unit, so that the constant temperature water is supplied to the two temperature control units respectively.

[0007] Preferably, it further includes a flow control device, which is disposed between the outlet of the constant temperature unit and the inlet of the first heat exchange channel and the inlet of the second heat exchange channel, for adjusting the flow rate of the constant temperature water flowing into the first heat exchange channel and the second heat exchange channel.

[0008] Preferably, the flow control device is a flow distribution valve.

[0009] Preferably, the flow control device consists of a first control valve and a second control valve respectively installed on the pipelines leading to the first heat exchange channel and the second heat exchange channel.

[0010] Preferably, it further includes a temperature sensor disposed at the process liquid outlet of the second temperature control unit; and a feedback control loop, wherein the controller adjusts the flow control device based on the deviation between the final temperature and the target temperature.

[0011] Preferably, the system further includes an incoming material temperature sensor, which is located at the process liquid inlet of the first temperature control unit. The controller is also electrically connected to the incoming material temperature sensor and performs feedforward control based on the temperature of the incoming process liquid.

[0012] Preferably, the feedback control loop further includes a first flow meter and a second flow meter disposed downstream of the flow control device.

[0013] Preferably, the heat exchange efficiency of the first temperature control unit is higher than that of the second temperature control unit.

[0014] Preferably, the design flow rate of the constant temperature water flowing into the first heat exchange channel is higher than the design flow rate of the constant temperature water flowing into the second heat exchange channel; or, the first temperature control unit is configured as a counter-current heat exchange structure; or, the second temperature control unit is a water bath constant temperature pipeline.

[0015] Preferably, the preset temperature of the constant temperature water provided by the constant temperature water unit remains constant during the temperature control process.

[0016] The technical solution of the present invention provides a method for temperature control of process liquid, which divides the constant temperature water flowing out of the constant temperature water unit into a first constant temperature water branch and a second constant temperature water branch; the process liquid flows through the first temperature control unit and the second temperature control unit in sequence for first-stage and second-stage temperature regulation, while the constant temperature water of the first and second constant temperature water branches flows through the first temperature control unit and the second temperature control unit respectively.

[0017] Preferably, it also includes adjusting the flow rates of the first constant temperature water branch and the second constant temperature water branch.

[0018] Preferably, the method further includes detecting the final temperature of the process liquid after the second-stage temperature adjustment; and adjusting the flow rates of the first and second constant-temperature water branches based on the deviation between the final temperature and the target temperature.

[0019] Preferably, the feedback adjustment step includes increasing the flow rate of the second constant temperature water branch when the final temperature is lower than the target temperature; and / or decreasing the flow rate of the second constant temperature water branch when the final temperature is higher than the target temperature.

[0020] Preferably, the method further includes detecting the incoming temperature of the process liquid before it flows through the first temperature control unit; and adjusting the initial set value of the flow rate ratio based on the temperature difference between the incoming temperature and the target temperature.

[0021] Preferably, the first-stage temperature regulation performs primary temperature regulation on the process liquid; the second-stage temperature regulation performs fine temperature regulation and heat preservation on the process liquid.

[0022] Preferably, the preset temperature is kept constant throughout the entire temperature control method.

[0023] The present invention provides a semiconductor wet processing apparatus, including a temperature control system for the process liquid described in any of the above claims.

[0024] The technical solution of this application mainly achieves coarse and fine control of the process liquid through a two-stage temperature control architecture of series connection of process liquid and parallel connection of constant temperature water. By differentiating the functions of the two-stage temperature control units, it can effectively cope with large fluctuations in the incoming material temperature, solving the problems of low accuracy and poor stability of existing single-stage temperature control solutions. Moreover, the above-mentioned temperature control operation is carried out continuously, and the temperature control process usually does not occupy additional process time, thus not affecting the operating efficiency of wet processing. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the basic structure of the process liquid temperature control system according to an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of the control loop of the process liquid temperature control system according to an embodiment of the present invention.

[0027] In the picture:

[0028] 100: Constant temperature water unit; 200: First temperature control unit; 210: First fluid channel; 220: First heat exchange channel; 300: Second temperature control unit; 301: Water bath constant temperature pipeline; 310: Second fluid channel; 320: Second heat exchange channel; 400: Nozzle; 500: Temperature sensor; 510: Incoming material temperature sensor; 600: Feedback control loop; 610: Controller; 700: Flow distribution valve; 710: First flow meter; 720: Second flow meter; 730: First control valve; 740: Second control valve. Detailed Implementation

[0029] The present patent type will be described in detail below with reference to the accompanying drawings and specific embodiments. In this specification, the dimensions in the drawings do not represent actual size ratios. The drawings are only used to illustrate the relative positional and connection relationships between the components. Components with the same name or the same reference numerals represent similar or identical structures and are limited to illustrative purposes.

[0030] Figure 1 This is a schematic diagram of the basic structure of the process liquid temperature control system according to an embodiment of the present invention. Whether supplied directly from the chemical supply system or by the internal liquid supply unit, the process liquid temperature often changes during its journey to the process point, causing a temperature deviation from the target process temperature. The target process temperature is defined under a specific process, such as 23 degrees Celsius in photolithography to ensure the development rate.

[0031] like Figure 1 As shown, a temperature control system is required for precise temperature control of the process liquid. This system typically has two temperature control units, which can be defined as a first temperature control unit 200 and a second temperature control unit 300. The process liquid flows sequentially through the first temperature control unit 200 and the second temperature control unit 300 for two-stage temperature regulation.

[0032] like Figure 2 The schematic diagram is shown. To simultaneously provide both coarse and fine temperature adjustment, the temperature control system also includes a constant temperature water unit 100. The outlet of the constant temperature water unit 100 is connected in parallel with the first heat exchange channel 220 of the first temperature control unit 200 and the second heat exchange channel 320 of the second temperature control unit 300 to achieve parallel water supply to the two temperature control units. If process liquid flows through the system at this time, under the designed two-stage temperature control, the temperature of the process liquid can be adjusted to the target temperature by the system, achieving precise temperature control.

[0033] Figure 1 This only illustrates one implementation of the temperature control system in this scheme. Generally, the first temperature control unit 200 and the second temperature control unit 300 are connected in series in the process liquid flow path to sequentially regulate the temperature of the process liquid during operation. In the optimized design, the heat exchange efficiency of at least one of the first temperature control unit 200 and the second temperature control unit 300 is adjustable. By controlling the constant temperature water flow rate into the first heat exchange channel 220 and the second heat exchange channel 320, precise regulation of the process liquid temperature can be achieved.

[0034] Figure 2 for Figure 1The control loop diagram of the embodiment is shown below. The system is also equipped with a flow control device. Specifically, it can be implemented by a flow distribution valve 700 or independent control valves (first control valve 730, second control valve 740). When the process liquid enters the system, the incoming material temperature sensor 510 detects its initial temperature, and the controller 610 presets a flow distribution ratio based on the difference between the initial temperature and the target temperature.

[0035] When adjusting the temperature of the process liquid, the process liquid first enters the first temperature control unit 200, where it undergoes the first stage of temperature adjustment, i.e., coarse adjustment. Then, the process liquid, after coarse adjustment, enters the second temperature control unit 300 for the second stage of temperature adjustment, i.e., fine adjustment, thereby precisely controlling its temperature at the target value.

[0036] Based on the above embodiments, the first temperature control unit 200 can preferably be designed as a unit with high heat exchange efficiency, while the second temperature control unit 300 can be designed as a unit with a gentler heat exchange process. This mainly addresses the contradiction between response speed and control accuracy in single-stage temperature control. In the technical solution of the above embodiments, the first temperature control unit 200 bears the main temperature control load, quickly eliminating large temperature fluctuations in the incoming liquid. In the improved solution, the second temperature control unit 300 is placed downstream of the first temperature control unit 200, fine-tuning the process liquid whose temperature is already close to the target value, reducing the risk of temperature overshoot caused by single-stage high-power regulation, thereby correspondingly improving the final accuracy of temperature control.

[0037] Figure 1 The illustrated embodiment is merely one technical solution for achieving precise temperature control of process liquids based on two-stage temperature control. In the structural design of the temperature control system, the first temperature control unit 200 and the second temperature control unit 300 are generally connected in series, but the constant temperature water supply method is designed to be in parallel. This is to ensure that both temperature control units can obtain the most stable temperature control medium, avoiding water temperature fluctuations in subsequent temperature control units that may be caused by series water supply. This is a key design for achieving high-precision control.

[0038] The aforementioned temperature control system can be applied to semiconductor wet processing equipment. Figure 2This is a schematic diagram of a temperature control system including a control loop. The device is equipped with a controller 610, such as a programmable logic controller (PLC) or a dedicated proportional-integral-derivative (PID) controller. A temperature sensor 500 is located at the process liquid outlet of the second temperature control unit 300 to detect the final temperature of the process liquid. The controller 610 is electrically connected to the temperature sensor 500 and the flow control device. In the general flow of temperature control, initially, the constant temperature water unit 100 outputs constant temperature water at a preset temperature. When the process liquid flows into the temperature control system, the incoming temperature sensor 510 detects its temperature, and the controller 610 performs feedforward control, setting the initial state of the flow control device. During the process liquid flow through the system, the first temperature control unit 200 and the second temperature control unit 300 receive a constant temperature water supply, allowing for coarse and fine adjustments to the liquid. In the above temperature control process, when the final temperature sensor 500 detects a temperature deviation from the target value, the controller 610 adjusts the flow control device to adjust the process liquid temperature, thus returning it to the precise temperature required by the process, completing the closed-loop temperature control.

[0039] Specific temperature control system designs are not limited to the embodiments described above. The temperature control system can be flexibly configured with components of the feedback control loop 600, such as... Figure 2 The solution shown includes a flow meter. Other similar control solutions are not limited to this. Figure 1 as well as Figure 2 As shown. In Figure 2 In the feedback control loop 600, a first flow meter 710 and a second flow meter 720 are also located downstream of the flow control device. Multiple sensors can be installed on the temperature control system to achieve precise closed-loop control. However, to improve control accuracy, the flow meters are preferably installed on their own independent constant-temperature water branches, meaning that the constant-temperature water flow into the two heat exchange channels can be monitored separately and without interference. Therefore, the controller 610 does not need to wait for each other when issuing flow regulation commands, which is expected to solve the limitation of inaccurate command execution under open-loop control, thereby improving the efficiency of its temperature control operation.

[0040] Corresponding to the temperature control system described above, its temperature control method can be based on Figure 2 Explanation: By controlling the flow rate of constant-temperature water into the first temperature control unit 200 and the second temperature control unit 300, the temperature of the process liquid changes, thereby restoring the temperature of the process liquid to the required state.

[0041] Temperature control can be achieved primarily through real-time feedback from sensors. Based on prior sensing of the incoming process liquid temperature, the direction and magnitude of its deviation from the target temperature are determined, and the target temperature for temperature control is predetermined. According to the deviation direction and target temperature, the heat exchange between the two-stage temperature control units after the process liquid enters the system is determined, causing the temperature difference of the process liquid to gradually decrease under the action of the two-stage temperature control. During this process, the final temperature of the process liquid can be obtained via temperature sensor 500, and when the process liquid temperature meets the required set value, a signal is sent to controller 610. Controller 610 maintains the state of the flow control device to ensure that the process liquid is maintained at the required temperature at the system outlet.

[0042] Temperature control can also be determined by pre-controlling the flow distribution of the flow control device based on the known inlet temperature. This feedforward control can be independent of the final temperature feedback. The process involves determining the temperature state of the process liquid upon entering the system based on other measured inputs (inlet temperature sensor 510). Since the required temperature profile is generally known in advance, the initial temperature difference of the process liquid can obviously be determined before the flow control device operates. This temperature difference can serve as the primary parameter for flow distribution control by the flow control device.

[0043] For systems with two-stage temperature control units, there are several options for temperature control methods. The first method achieves temperature control through the cooperation between the two units. Specifically, the first temperature control unit 220 receives the incoming process liquid and performs coarse adjustment, then adjusts the temperature of the process liquid to a preset range, such as ±0.5 degrees Celsius of the target temperature. The pre-adjusted process liquid is then delivered to the downstream second temperature control unit 300, where fine temperature adjustment is performed. During this process, the flow rates of the corresponding two constant-temperature water branches can be optionally controlled, ensuring that the two temperature control units are not only functionally distinct but also correspond in terms of adjustment magnitude.

[0044] The second method involves achieving coordinated control of the entire system through a single controller. Even if the temperature control system has two temperature control units, the heat exchange of the two units remains relatively independent and does not interfere with each other. The initial temperature of the incoming process liquid is obtained, and then the controller 610 coordinates the flow rate of the two constant-temperature water branches based on feedback from this temperature and the final temperature. For this system and the process liquid that needs to be regulated, the initial and final temperatures of the process liquid are detected and determined before temperature control. Then, the controller 610 adjusts the flow distribution, ensuring at least the heat exchange during the fine-tuning stage, and optionally including the heat exchange during the coarse-tuning stage. The difference lies in the reference set for coarse-tuning and fine-tuning, which is based on the deviation between the determined incoming and final temperatures. When the incoming temperature fluctuates, since the controller has already adjusted the flow distribution, the system can directly perform temperature control operations on the process liquid.

[0045] The above description is merely a preferred embodiment of this patent type and is not intended to limit the scope of this patent type. Without departing from the design spirit of this patent type, all modifications and improvements made by those skilled in the art to the technical solutions of this patent type should fall within the protection scope defined by the claims of this patent type.

Claims

1. A temperature control system for a process liquid, characterized in that, include: Thermostatic water unit, used to provide water at a preset temperature; A first temperature control unit, the first temperature control unit having a first fluid channel for passing process liquid and a first heat exchange channel for passing constant temperature water; The second temperature control unit has a second fluid channel for passing process liquid and a second heat exchange channel for passing constant temperature water. The process liquid is configured to flow sequentially through the first fluid channel of the first temperature control unit and the second fluid channel of the second temperature control unit. Furthermore, the outlet of the constant temperature water unit is connected in parallel with the inlet of the first heat exchange channel of the first temperature control unit and the inlet of the second heat exchange channel of the second temperature control unit, so that the constant temperature water provided by the constant temperature water unit is supplied to the first temperature control unit and the second temperature control unit respectively.

2. The temperature control system for the process liquid as described in claim 1, characterized in that, It also includes a flow control device, which is installed between the outlet of the constant temperature water unit and the inlet of the first heat exchange channel and the inlet of the second heat exchange channel, for adjusting the flow rate of the constant temperature water flowing into the first heat exchange channel and the second heat exchange channel.

3. The temperature control system for the process liquid as described in claim 2, characterized in that, The flow control device is a flow distribution valve, used to adjust the flow ratio of constant temperature water flowing from the constant temperature water unit into the first heat exchange channel and the second heat exchange channel.

4. The temperature control system for the process liquid as described in claim 2, characterized in that, The flow control device consists of a first control valve and a second control valve respectively installed on the pipelines leading to the first heat exchange channel and the second heat exchange channel, and is used to independently control the flow rate of constant temperature water flowing into the two heat exchange channels.

5. The temperature control system for the process liquid as described in claim 2, characterized in that, Also includes: A temperature sensor is installed at the process liquid outlet of the second temperature control unit to detect the final temperature of the process liquid. as well as A feedback control loop, the feedback control loop including a controller electrically connected to the temperature sensor and the flow control device; The controller adjusts the flow control device to change the flow rate of the constant-temperature water flowing into the first heat exchange channel and / or the second heat exchange channel based on the deviation between the final temperature and the target temperature.

6. The temperature control system for the process liquid as described in claim 5, characterized in that, It also includes an incoming material temperature sensor, which is installed at the process liquid inlet of the first temperature control unit to detect the temperature of the incoming process liquid; The controller is also electrically connected to the incoming material temperature sensor and performs feedforward control based on the temperature of the incoming process liquid to pre-adjust the flow control device.

7. The temperature control system for the process liquid as described in claim 5, characterized in that, The feedback control loop also includes a first flow meter and a second flow meter disposed downstream of the flow control device. The first flow meter and the second flow meter are used to monitor the flow rate of the constant temperature water flowing into the first heat exchange channel and the second heat exchange channel, respectively, and feed the flow signal back to the controller.

8. The temperature control system for the process liquid as described in claim 1, characterized in that, The heat exchange efficiency of the first temperature control unit is higher than that of the second temperature control unit, so that the first temperature control unit performs the main temperature regulation of the process liquid, while the second temperature control unit performs fine temperature regulation and heat preservation of the process liquid.

9. The temperature control system for the process liquid as described in claim 8, characterized in that, The design flow rate of the constant-temperature water flowing into the first heat exchange channel is higher than the design flow rate of the constant-temperature water flowing into the second heat exchange channel; or, The first fluid channel and the first heat exchange channel of the first temperature control unit are configured as a counter-current heat exchange structure; or, The second temperature control unit is a water bath thermostatic pipeline.

10. The temperature control system for the process liquid as described in claim 1, characterized in that, The preset temperature of the constant temperature water provided by the constant temperature water unit remains constant during the temperature control process.

11. A method for temperature control of a process liquid, characterized in that, Includes the following steps: The constant temperature water unit provides water at a preset temperature; The constant temperature water flowing out of the constant temperature water unit is divided into a first constant temperature water branch and a second constant temperature water branch. The process liquid is made to flow through the first temperature control unit, and at the same time, the constant temperature water in the first constant temperature water branch is made to flow through the first temperature control unit to perform the first stage of temperature regulation on the process liquid. The process liquid that has undergone the first stage of temperature regulation flows through the second temperature control unit, and at the same time, the constant temperature water from the second constant temperature water branch flows through the second temperature control unit to perform a second stage of temperature regulation on the process liquid.

12. The temperature control method for the process liquid as described in claim 11, characterized in that, It also includes adjusting the flow rates of the first and second constant temperature water branches to control the heat exchange of the first and second stage temperature regulation, respectively.

13. The temperature control method for the process liquid as described in claim 12, characterized in that, Also includes: After the second stage of temperature adjustment, the final temperature of the process liquid is detected; as well as Based on the deviation between the final temperature and the target temperature, the flow rates of the first and second constant temperature water branches are adjusted accordingly.

14. The temperature control method for the process liquid as described in claim 13, characterized in that, The feedback adjustment step includes increasing the flow rate of the second constant temperature water branch when the final temperature is lower than the target temperature; And / or, when the final temperature is higher than the target temperature, reduce the flow rate of the second constant temperature water branch.

15. The temperature control method for the process liquid as described in claim 14, characterized in that, Also includes: The incoming temperature of the process liquid is detected before it flows through the first temperature control unit; as well as Based on the temperature difference between the incoming material temperature and the target temperature, the initial set value of the flow ratio of the first constant temperature water branch and the second constant temperature water branch is adjusted by feedforward.

16. The temperature control method for the process liquid as described in claim 11, characterized in that, The first-stage temperature regulation performs primary temperature regulation on the process liquid to adjust the temperature of the process liquid to a preset range of the target temperature; and the second-stage temperature regulation performs fine temperature regulation and heat preservation on the process liquid to precisely control the temperature of the process liquid at the target temperature.

17. The temperature control method for the process liquid as described in claim 11, characterized in that, The step of providing constant temperature water with a preset temperature includes maintaining the preset temperature constant throughout the execution of the temperature control method.

18. A semiconductor wet processing apparatus, characterized in that, Including the temperature control system for process liquids as described in any one of claims 1-10.

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