Temperature control system inside a lithography machine

Abstract

Provided is an internal temperature control system of a photoetching machine, comprising: a temperature sensor for detecting an actual temperature; a primary temperature control system comprising a primary temperature controller for controlling temperature within a first temperature range; and a secondary temperature control system comprising a secondary temperature controller for controlling temperature within a second temperature range smaller than the first temperature range; wherein the primary temperature controller operates in response to a difference between the actual temperature and a target temperature being less than or equal to a first temperature threshold corresponding to the first temperature range and greater than a second temperature threshold corresponding to the second temperature range; and the secondary temperature controller operates in response to the difference between the actual temperature and the target temperature being less than or equal to the second temperature threshold corresponding to the second temperature range. In this way, stability of temperature control is improved.

Description

Technical Field

[0001] This application relates to the field of lithography machine technology, and more specifically, to an internal temperature control system for a lithography machine. Background Technology

[0002] Photolithography machines are essential equipment in the semiconductor manufacturing process. Their function is to precisely transfer circuit patterns from a photomask (also known as a mask) to a silicon wafer or other substrate according to predetermined dimensions and positions through an exposure process.

[0003] Because lithography machines are typically installed in highly controlled environments, such as cleanrooms, the stability of the ambient temperature is critical to ensure the precision of the lithography process, usually on the order of 0.01°C. However, the sensors and temperature controllers in the temperature control systems of current lithography machines are often from different brands and manufacturers, and come in different forms such as air-cooled and water-cooled, thus affecting the temperature control of the lithography machine.

[0004] Therefore, it is desirable to provide an improved internal temperature control system for lithography machines. Summary of the Invention

[0005] This application provides an internal temperature control system for a lithography machine, which improves the stability of temperature control by using a multi-level temperature control system with different temperature control ranges to control the temperature based on the difference between the actual temperature and the target temperature.

[0006] According to one aspect of this application, a temperature control system for an internal temperature of a lithography machine is provided, comprising: a temperature sensor for detecting the actual temperature; a primary temperature control system including a primary temperature controller for controlling the temperature within a first temperature range; and a secondary temperature control system including a secondary temperature controller for controlling the temperature within a second temperature range less than the first temperature range.

[0007] Specifically, the first-level temperature controller operates in response to the difference between the actual temperature and the target temperature being less than or equal to a first temperature threshold corresponding to the first temperature range and greater than a second temperature threshold corresponding to the second temperature range; and the second-level temperature controller operates in response to the difference between the actual temperature and the target temperature being less than or equal to a second temperature threshold corresponding to the second temperature range.

[0008] The aforementioned internal temperature control system of the lithography machine further includes: a three-level temperature control system, including a three-level temperature controller for controlling the temperature within a third temperature range less than the second temperature range; wherein, the second-level temperature controller operates in response to the difference between the actual temperature and the target temperature being less than or equal to a second temperature threshold corresponding to the second temperature range and greater than a third temperature threshold corresponding to the third temperature range; and the third-level temperature controller operates in response to the difference between the actual temperature and the target temperature being less than or equal to a third temperature threshold corresponding to the third temperature range.

[0009] In the above-mentioned temperature control system inside the lithography machine, both the primary temperature controller and the secondary temperature controller operate when the difference between the actual temperature and the target temperature is greater than a first temperature threshold corresponding to the first temperature range.

[0010] In the above-mentioned temperature control system inside the lithography machine, the first-level temperature controller, the second-level temperature controller, and the third-level temperature controller all operate when the difference between the actual temperature and the target temperature is greater than the first temperature threshold corresponding to the first temperature range.

[0011] In the above-mentioned temperature control system inside the lithography machine, the first temperature range is ±1℃, the second temperature range is ±0.1℃, and the third temperature range is ±0.01℃.

[0012] In the above-mentioned temperature control system inside the lithography machine, the temperature sensor includes a first-level temperature sensor corresponding to the first-level temperature control system with a first sensing accuracy corresponding to the first temperature range, a second-level temperature sensor corresponding to the second-level temperature control system with a second sensing accuracy corresponding to the second temperature range, and a third-level temperature sensor corresponding to the third-level temperature control system with a third sensing accuracy corresponding to the third temperature range.

[0013] In the above-mentioned temperature control system inside the lithography machine, in the first-level control, the actual temperature detected by the first-level temperature sensor is sent as a first-level feedforward signal to the second-level temperature controller, and the second-level temperature controller performs temperature control based on the actual temperature detected by the second-level temperature sensor and the first-level feedforward signal.

[0014] In the above-mentioned temperature control system inside the lithography machine, in the second-level control, the actual temperature detected by the second-level temperature sensor is sent as a second-level feedback signal to the first-level temperature controller. The first-level temperature controller performs temperature control based on the second-level feedback signal. The second-level temperature controller performs temperature control based on the actual temperature detected by the second-level temperature sensor, and the actual temperature detected by the second-level temperature sensor is sent as a second-level feedforward signal to the third-level temperature controller.

[0015] In the above-mentioned temperature control system inside the lithography machine, in the third-level control, the third-level temperature controller performs temperature control based on the actual temperature detected by the third-level temperature sensor and the second-level feedforward signal, and sends the actual temperature detected by the third-level temperature sensor as a third-level feedback signal to the second-level temperature controller, which then performs temperature control based on the third-level feedback signal.

[0016] In the temperature control system inside the aforementioned lithography machine, the output of the temperature sensor is an analog signal.

[0017] The internal temperature control system of the lithography machine provided in this application embodiment can improve the stability of temperature control by using a multi-level temperature control system with different temperature control ranges to control the temperature based on the difference between the actual temperature and the target temperature. Attached Figure Description

[0018] Various other advantages and benefits of this application will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0019] Figure 1 The figure shows a schematic diagram of the internal temperature control system of a lithography machine according to an embodiment of this application.

[0020] Figure 2 The figure shows a schematic diagram of three levels of the internal temperature control system of a lithography machine according to an embodiment of the present application.

[0021] Figure 3 The figure shows a schematic diagram of the hardware module of the internal temperature control system of a lithography machine according to an embodiment of this application.

[0022] Figure 4A and Figure 4BThe illustration shows a schematic diagram of a hybrid control strategy for the internal temperature control system of a lithography machine according to an embodiment of this application. Detailed Implementation

[0023] Hereinafter, exemplary embodiments according to this application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments of this application. It should be understood that this application is not limited to the exemplary embodiments described herein.

[0024] In this embodiment, the internal temperature control system of the lithography machine is divided into multiple levels, such as... Figure 1 As shown. Here, Figure 1 The illustration shows a schematic diagram of the internal temperature control system of a lithography machine according to an embodiment of this application. Figure 1 As shown, the internal temperature control system of the lithography machine includes a primary temperature control system and a secondary temperature control system. The primary temperature control system includes a primary temperature controller for controlling the temperature within a first temperature range, while the secondary temperature control system includes a secondary temperature controller for controlling the temperature within a second temperature range less than the first temperature range.

[0025] Furthermore, the internal temperature control system of the lithography machine according to embodiments of this application may also include more levels. For example, Figure 2 The diagram illustrates a three-level internal temperature control system for a lithography machine according to an embodiment of this application. Figure 2 As shown, the internal temperature control system of the lithography machine has three levels: Level 1 is 1A, Level 2 is 2A and 2B, and Level 3 is 3A, 3B, 3C, and 3D. Furthermore, the control precision of each level of the temperature control system is different. For example, in the Level 1 control system, the temperature control precision is ±1℃; in the Level 2 control system, the temperature control precision is ±0.1℃; and in the Level 3 control system, the temperature control precision is ±0.01℃. Of course, those skilled in the art will understand that the above-mentioned control precision values ​​for Level 1, Level 2, and Level 3 control systems are merely examples. In practice, it is only necessary for the Level 2 control system to have a higher control precision than the Level 1 control system, and for the Level 3 control system to have a higher control precision than the Level 2 control system. For example, the control precision of the Level 1, Level 2, and Level 3 control systems can be ±1℃, ±0.5℃, and ±0.2℃, respectively. Moreover, in the embodiments of this application, each control system at each level, such as 1A, 2A, and 3A, includes a corresponding temperature controller and temperature sensor.

[0026] Here, in the internal temperature control system of the lithography machine according to an embodiment of this application, when the difference between the actual temperature and the target temperature is large, for example, when the system is first started or restarted after a long shutdown, the ambient temperature may differ significantly from the preset target temperature, for example, T. In this case, in order to quickly adjust the temperature to near the set value, the heating module processing board or the cooling module processing board will command all temperature controllers to operate at full power, whether for heating or cooling. This step is to quickly reduce the difference between the actual temperature and the target temperature.

[0027] Once the temperature sensor detects that the actual temperature is close to the target temperature, for example, within the range of T ± 1℃, the temperature controller of the first-level control system will start operating. The temperature controller will adjust the heating or cooling intensity based on the current temperature deviation, gradually approaching the target temperature in a smoother manner. The goal of this stage is to avoid over-adjustment caused by excessively rapid temperature changes, while simultaneously stabilizing the temperature as quickly as possible.

[0028] Once the temperature stabilizes further and the range of variation decreases to, for example, within T ± 0.1℃, the temperature controller of the second-level secondary control system takes over. This second-level temperature controller has higher resolution and can more precisely adjust heat input or output to prevent large temperature fluctuations. This step helps achieve higher precision temperature control.

[0029] Finally, when the temperature is extremely close to the set value, for example, within the range of T ± 0.01℃, the temperature controller of the third-level three-stage control system will be activated. The temperature controllers of this third-level three-stage control system are typically designed specifically for achieving extremely precise temperature control; their task is to maintain a constant temperature within a range of minute temperature variations.

[0030] It is worth noting that although the above description uses the internal temperature control system of a lithography machine as an example, the temperature control system according to the embodiments of this application is not limited to lithography machines, but can also be applied to other temperature control scenarios that require high temperature control stability.

[0031] Based on this, this application provides an internal temperature control system for a lithography machine, comprising: a temperature sensor for detecting the actual temperature; a primary temperature control system including a primary temperature controller for controlling the temperature within a first temperature range; and a secondary temperature control system including a secondary temperature controller for controlling the temperature within a second temperature range less than the first temperature range; wherein, the primary temperature controller operates in response to the difference between the actual temperature and the target temperature being less than or equal to a first temperature threshold corresponding to the first temperature range and greater than a second temperature threshold corresponding to the second temperature range; and the secondary temperature controller operates in response to the difference between the actual temperature and the target temperature being less than or equal to the second temperature threshold corresponding to the second temperature range.

[0032] Furthermore, the aforementioned internal temperature control system of the lithography machine further includes a three-level temperature control system, including a three-level temperature controller for controlling the temperature within a third temperature range less than the second temperature range; wherein, the second-level temperature controller operates in response to the difference between the actual temperature and the target temperature being less than or equal to a second temperature threshold corresponding to the second temperature range and greater than a third temperature threshold corresponding to the third temperature range; and the third-level temperature controller operates in response to the difference between the actual temperature and the target temperature being less than or equal to a third temperature threshold corresponding to the third temperature range.

[0033] Furthermore, in the aforementioned temperature control system inside the lithography machine, in response to the difference between the actual temperature and the target temperature being greater than a first temperature threshold corresponding to the first temperature range, the primary temperature controller, the secondary temperature controller, and the tertiary temperature controller all operate.

[0034] Furthermore, in the aforementioned temperature control system inside the lithography machine, the first temperature range is ±1℃, the second temperature range is ±0.1℃, and the third temperature range is ±0.01℃.

[0035] Figure 3 The illustration shows a schematic diagram of the hardware module of the internal temperature control system of a lithography machine according to an embodiment of this application. For example... Figure 3 As shown, the sensor signal processing board, based on the temperature sensed by the temperature sensor, activates the heating and cooling modules via the heating module processing board and the cooling module processing board to control the temperature of the lithography machine.

[0036] Furthermore, in this embodiment, to improve the adaptability and robustness of the automatic temperature control of the lithography machine, and thus enhance the temperature control stability, a hybrid control strategy based on feedforward and feedback is adopted. Specifically, during automatic temperature control, the temperature detected by the temperature sensor at the previous stage is used as the feedforward of the current stage temperature controller, while the temperature detected by the current stage temperature sensor is used as the feedback of the previous stage temperature controller, such as... Figure 4A and Figure 4B As shown. Figure 4A and Figure 4B The illustration shows a schematic diagram of a hybrid control strategy for the internal temperature control system of a lithography machine according to an embodiment of this application.

[0037] like Figure 4A As shown, for example, when the preset temperature in the entire lithography machine is T, the temperature detected by the 1A temperature sensor is T. 1A (Accuracy ±1℃), the temperature detected by the 2A temperature sensor is T. 2A (Accuracy ±0.1℃), at this point, the temperature that needs to be adjusted for the 2A temperature controller is (TT). 2A For temperature controller 1A, the temperature that needs to be adjusted is (TT). 1A For 1A and 2A temperature controllers, the adjustment (TT) 1A )℃ ratio adjustment (TT) 2A The response speed is faster at 1℃. Therefore, when temperature controller 1A controls the temperature at T±1℃, temperature controller 2A then controls the temperature. This process continues for the three temperature controller levels.

[0038] In this way, the temperature detected by the previous-stage temperature sensor is used as a feedforward signal for the next-stage temperature controller. This means that when the previous-stage temperature sensor detects a temperature deviation from the set value, the information it provides can help the next-stage temperature controller react in advance, thereby adjusting the temperature more quickly to reach the set value. For example, when the 1A temperature sensor detects a temperature of T... 1A At that time, the 2A temperature controller can adjust its output in advance based on this information, so that the adjustment (TT) 2A The process at ℃ is faster.

[0039] Simultaneously, the temperature detected by the current-level temperature sensor is also fed back to the previous-level temperature controller as a feedback signal. This means that if the current-level temperature sensor detects a temperature change, it will affect the behavior of the previous-level temperature controller, enabling the system to maintain temperature stability over a wider range. For example, if the 2A temperature sensor detects a temperature of T... 2A Then the 2A temperature controller needs to be adjusted (TT) 2A )℃, and this information will affect the operation of the 1A temperature controller.

[0040] For example, assuming the temperature in the lithography machine is to be maintained at 22°C, if the system detects that the temperature has risen too much during full-power operation, the cooling module will run at full power and quickly adjust the temperature to close to 22.00°C.

[0041] In the first level of control, temperature sensor 1A detects a temperature of 23°C. At this point, sensor 1A sends this 23°C information as a feedforward signal to temperature controller 2A. Temperature sensor 2A detects a temperature of 22.5°C, and based on this feedforward signal, temperature controller 2A increases the cooling power in advance to prevent the temperature from rising further. Meanwhile, temperature controller 1A continues to operate, gradually adjusting the cooling intensity.

[0042] In the second level of control, temperature sensor 2A detects a temperature of 22.1℃. At this point, sensor 2A sends this 22.1℃ information as a feedback signal to temperature controller 1A. Temperature controller 1A makes fine adjustments based on the feedback signal, increasing the cooling capacity to accelerate the temperature drop. Meanwhile, temperature controller 2A, based on the precise data from temperature sensor 2A, performs even finer temperature regulation, stabilizing the temperature around 22.0℃. Simultaneously, temperature sensor 2A sends the 22.1℃ information as a feedforward signal to temperature controller 3A.

[0043] In the third level of control, temperature sensor 3A detects a temperature of 22.01℃. At this point, temperature controller 3A makes fine adjustments based on the feedforward signal (22.1℃) to maintain the temperature around 22.00℃. Furthermore, temperature sensor 3A feeds back any minute temperature changes (e.g., 22.05℃) to temperature controller 2A. Temperature controller 2A makes necessary adjustments based on the feedback from temperature sensor 3A to ensure temperature fluctuations are minimized.

[0044] Therefore, in the internal temperature control system of the lithography machine according to the embodiments of this application, the temperature sensor includes a first-level temperature sensor corresponding to the first-level temperature control system with a first sensing accuracy corresponding to the first temperature range, a second-level temperature sensor corresponding to the second-level temperature control system with a second sensing accuracy corresponding to the second temperature range, and a third-level temperature sensor corresponding to the third-level temperature control system with a third sensing accuracy corresponding to the third temperature range.

[0045] Furthermore, in the aforementioned temperature control system inside the lithography machine, in the first-level control, the actual temperature detected by the first-level temperature sensor is sent as a first-level feedforward signal to the second-level temperature controller, and the second-level temperature controller performs temperature control based on the actual temperature detected by the second-level temperature sensor and the first-level feedforward signal.

[0046] Furthermore, in the aforementioned temperature control system inside the lithography machine, in the second-level control, the actual temperature detected by the secondary temperature sensor is sent as a secondary feedback signal to the primary temperature controller. The primary temperature controller performs temperature control based on the secondary feedback signal, and the secondary temperature controller performs temperature control based on the actual temperature detected by the secondary temperature sensor. The actual temperature detected by the secondary temperature sensor is also sent as a secondary feedforward signal to the tertiary temperature controller.

[0047] Furthermore, in the aforementioned temperature control system inside the lithography machine, in the third-level control, the third-level temperature controller performs temperature control based on the actual temperature detected by the third-level temperature sensor and the second-level feedforward signal, and sends the actual temperature detected by the third-level temperature sensor as a third-level feedback signal to the second-level temperature controller, which then performs temperature control based on the third-level feedback signal.

[0048] Therefore, by using the temperature of the previous level as a feedforward input to the next level controller, while simultaneously sending the actual temperature of the current level as feedback to the higher level controller, the adaptability and robustness of the temperature control system inside the lithography machine are enhanced. Furthermore, as the layers deepen, the temperature control accuracy gradually improves, ultimately achieving an extremely high accuracy of ±0.01℃ at the third level, which is crucial for lithography machine temperature control applications requiring extremely small temperature fluctuations.

[0049] Furthermore, the aforementioned hybrid control strategy helps improve the overall stability and anti-interference capability of the temperature control system inside the lithography machine. In this way, feedforward control enables the system to anticipate and respond to potential temperature changes in advance, while feedback control ensures that even in the event of unexpected situations, the system can quickly adjust to maintain temperature stability. This multi-level control system, combining feedforward and feedback mechanisms, significantly improves the speed and accuracy of temperature control, guaranteeing the high-quality execution of the lithography process.

[0050] Furthermore, in this embodiment, the output of the temperature sensor is preferably an analog signal, rather than communicating via a network interface (such as an Ethernet port) or a serial interface (such as RS-232). The advantage of using analog signals is that they can be transmitted directly through a physical connection without requiring complex protocol conversion and data packet processing. That is, by reducing latency and potential errors in the data conversion process, analog signals can provide faster response speeds and higher signal accuracy, thereby reducing latency and improving the real-time performance and reliability of the system. This also improves the speed and accuracy of signal processing, which is highly advantageous for applications with high real-time requirements.

[0051] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0052] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0053] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0054] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0055] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. An internal temperature control system of a lithography machine, comprising: a temperature sensor for detecting an actual temperature; a primary temperature control system including a primary temperature controller for controlling temperature within a first temperature range; and a secondary temperature control system including a secondary temperature controller for controlling temperature within a second temperature range smaller than the first temperature range; wherein the primary temperature controller operates in response to a difference between the actual temperature and a target temperature being less than or equal to a first temperature threshold corresponding to the first temperature range and greater than a second temperature threshold corresponding to the second temperature range; and the secondary temperature controller operates in response to the difference between the actual temperature and the target temperature being less than or equal to the second temperature threshold corresponding to the second temperature range; wherein the temperature sensor includes a primary temperature sensor corresponding to the primary temperature control system, and a secondary temperature sensor corresponding to the secondary temperature control system; in a first level of control, the actual temperature detected by the primary temperature sensor is sent as a primary feedforward signal to the secondary temperature controller, and the secondary temperature controller controls temperature based on the actual temperature detected by the secondary temperature sensor and the primary feedforward signal; in a second level of control, the actual temperature detected by the secondary temperature sensor is sent as a secondary feedback signal to the primary temperature controller, and the primary temperature controller controls temperature based on the secondary feedback signal.

2. The internal temperature control system of a lithography machine of claim 1, further comprising: a tertiary temperature control system including a tertiary temperature controller for controlling temperature within a third temperature range smaller than the second temperature range; wherein the secondary temperature controller operates in response to the difference between the actual temperature and the target temperature being less than or equal to the second temperature threshold corresponding to the second temperature range and greater than a third temperature threshold corresponding to the third temperature range; and the tertiary temperature controller operates in response to the difference between the actual temperature and the target temperature being less than or equal to the third temperature threshold corresponding to the third temperature range. the primary temperature controller and the secondary temperature controller both operate in response to the difference between the actual temperature and the target temperature being greater than the first temperature threshold corresponding to the first temperature range.

3. The lithography internal temperature control system of claim 1, wherein, the primary temperature controller, the secondary temperature controller and the tertiary temperature controller all operate in response to the difference between the actual temperature and the target temperature being greater than the first temperature threshold corresponding to the first temperature range.

4. The lithography internal temperature control system of claim 2, wherein, the first temperature range is ±1°C, the second temperature range is ±0.1°C, and the third temperature range is ±0.01°C.

5. The lithography internal temperature control system of claim 4, wherein, the primary temperature sensor has a first sensing accuracy corresponding to the first temperature range, the secondary temperature sensor has a second sensing accuracy corresponding to the second temperature range, and the temperature sensor includes a tertiary temperature sensor corresponding to the tertiary temperature control system having a third sensing accuracy corresponding to the third temperature range.

6. The lithography internal temperature control system of claim 2, wherein, ​ 7. The lithography internal temperature control system of claim 6, wherein, The secondary temperature controller controls temperature according to an actual temperature detected by the secondary temperature sensor, and the actual temperature detected by the secondary temperature sensor is sent to the tertiary temperature controller as a secondary feedforward signal.

8. The lithography internal temperature control system of claim 7, wherein, In the third level control, the tertiary temperature controller controls temperature according to the actual temperature detected by the tertiary temperature sensor and the secondary feedforward signal, and sends the actual temperature detected by the tertiary temperature sensor to the secondary temperature controller as a tertiary feedback signal, and the secondary temperature controller controls temperature according to the tertiary feedback signal.

9. The lithography inner temperature control system of any of claims 1-8, wherein, The output of the temperature sensor is an analog signal.

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