A multi-layered zoned lithography objective surface temperature control device

Abstract

The application discloses a kind of multilayer regional photolithography objective lens surface temperature control device.The cooling element includes multilayer internal flow passage non-interference cooling module, the first cooling medium is circulated in the internal flow passage of cooling element, the second cooling medium is circulated in the gap between the inner wall of cooling element and the outer wall of objective lens, and the third cooling medium forms air curtain between the outer wall of cooling element and the external environment;Micro heat exchanger is arranged at the inlet of each cooling module, and flow regulating valve and flow meter are arranged at the outlet;The temperature and flow of the first, second and third cooling medium flowing in are dynamically regulated and controlled by the host computer.The application can form a non-uniform cooling intensity field matched with the non-uniform thermal load of the objective lens through the synergistic effect of multilayer medium and the independent control system of multiple input and multiple output, thereby significantly improving the temperature uniformity, control accuracy and response speed of the objective lens surface of the photolithography machine.

Description

Technical Field

[0001] This invention relates to the field of temperature control technology for photolithography equipment, and in particular to a temperature control device for the surface of a multi-layered, regionalized photolithography objective lens. Background Technology

[0002] Temperature control of the projection lens surface is crucial to ensuring photolithography quality. The main requirements for temperature control of the lens surface are stability and uniformity.

[0003] In projection lens scenarios, although the absolute value of heat load changes is usually small (milliwatt level), the resulting temperature changes and deformations are amplified due to the thermal leverage effect, ultimately directly affecting the imaging quality of the lens.

[0004] Existing technology typically involves encasing the projection lens in a cylindrical jacket with serpentine or spiral-shaped pipes arranged on its outer surface, carrying cooling water internally and having one or two sets of inlets and outlets externally. By changing the inlet temperature or flow rate of the water jacket, the boundary conditions around the entire lens frame are affected. This is a global coarse adjustment, which at most can only achieve a uniform temperature on the inner wall of the objective lens cooling water jacket. However, the ultimate goal of the cooling water jacket is not its own temperature uniformity, but rather the consistent temperature of the mounting interfaces of each lens element, i.e., a uniform temperature on the outer surface of the objective lens.

[0005] Relying solely on a water jacket with a uniform surface temperature is insufficient to achieve the required uniform temperature across the entire objective lens's outer surface. Firstly, the objective lens itself is not a regular heat source; the light source is not perfectly symmetrical. Based on the working principle of photolithography scanning exposure, the light intensity distribution inside the objective lens is dynamic in both time and space. Although it may become uniform over time, the instantaneous heat load is constantly shifting and changing. Secondly, the objective lens frame integrates sensors, actuators, and electronic circuitry, whose positions are determined by mechanical and optical requirements and are typically non-uniformly distributed. Thirdly, the inner wall of the cooling water jacket is usually a cylinder with the same diameter at both ends, while the objective lens, due to its structural requirements, typically consists of a dozen or so cylinders of varying diameters and locking components on its outer surface. For easier assembly and disassembly, the inner diameter of the cooling water jacket is usually larger than the maximum outer diameter of the objective lens. This structure introduces an axially uneven air gap between the objective lens and the water jacket, creating spatially uneven thermal resistance. Finally, the ambient temperature outside the cooling water jacket may also be unevenly distributed.

[0006] Therefore, relying solely on traditional cooling water jackets cannot meet the requirements of higher precision projection lenses. How to further improve the surface temperature uniformity of the lens has become an urgent problem for researchers in this field. Summary of the Invention

[0007] The purpose of this invention is to address the problem that a single water jacket in the prior art cannot cope with complex heat source distribution and environmental interference, making it difficult to achieve uniform temperature across the entire objective lens surface. This invention proposes a multi-layer, regionalized objective lens surface temperature control device.

[0008] The present invention includes a cooling element, an air supply assembly, a miniature heat exchanger, a flow regulating valve, and a host computer disposed on the outer wall of an objective lens; the cooling element comprises multiple layers of cooling modules with independent internal flow channels, the multiple cooling modules being divided into regions according to the geometry and thermophysical properties of the objective lens; the multiple cooling modules are stacked or spliced ​​together to form the cooling element, with a gap between the inner wall of the cooling element and the outer wall of the objective lens; at the same time, multiple air inlets are opened on the cooling element; one or more air supply assemblies are disposed along the objective lens axis at the object end of the objective lens to form an air curtain on the outer surface of the cooling element;

[0009] Each cooling module has a temperature sensor installed on its inner wall, and the objective lens also has a temperature sensor installed on its outer wall.

[0010] A first cooling medium flows through the internal flow channel of the cooling element, a second cooling medium flows through the gap between the inner wall of the cooling element and the outer wall of the objective lens, and the air curtain is an isolation layer formed by a third cooling medium between the outer wall of the cooling element and the external environment.

[0011] Each cooling module is equipped with a miniature heat exchanger at the first cooling medium inlet and a flow regulating valve and flow meter at the first cooling medium outlet of each cooling module.

[0012] The host computer controls the temperature and flow rate of the first, second, and third cooling media flowing into the system. Simultaneously, it uses the temperature collected by various temperature sensors to control the micro heat exchanger and flow regulating valve to fine-tune the temperature and flow rate of the first cooling media, and to dynamically regulate the temperature and flow rate of the second and third cooling media.

[0013] Preferably, the first cooling medium is deionized water with high specific heat capacity and good thermal conductivity. The temperature setpoint of the first cooling medium flowing into each cooling module is usually lower than the target value for objective lens temperature control.

[0014] Preferably, the second cooling medium is an inert gas with stable chemical properties and low thermal conductivity.

[0015] Preferably, the third cooling medium is clean air.

[0016] Furthermore, the multiple air inlets are distributed circumferentially or axially, and a flow equalization device is provided at the air inlets.

[0017] Furthermore, the air outlet of the air supply assembly is arranged in a ring around the outer periphery of the cooling element, forming an air curtain on the outer surface of the cooling element.

[0018] Furthermore, the third cooling medium first enters a static pressure chamber for pressure stabilization and uniform flow, and then is evenly distributed through an annular air outlet to form an air curtain.

[0019] Furthermore, the cooling modules are set along the reinforcing ribs and bolt connection lines of the projection lens, and each cooling module's joint surface is also provided with a heat insulation layer or heat insulation structure.

[0020] Furthermore, for local areas with high heat load or potential for sudden increases in heat load, independent cooling modules are defined, with the internal flow channels of these modules designed as a multi-level branching / merging distributed network structure.

[0021] Furthermore, the host computer calculates the temperature and flow rate settings of the first cooling medium by comparing the real-time temperature monitoring value of the objective lens surface with the target temperature. By comparing the temperature detected by the temperature sensors on the inner walls of each cooling module with the temperature detected by the temperature sensors on the outer walls of the corresponding areas of the objective lens, the equivalent thermal resistance and heat flux density of the gap in that area are estimated in real time. Based on the comparison of the equivalent thermal resistance and heat flux density with the target temperature, the temperature control target to be achieved by each cooling module is obtained. Then, the temperature and flow rate of the first cooling medium flowing into each cooling module are finely adjusted locally through the miniature heat exchangers and flow regulating valves of each cooling module. The temperature and flow rate of the second cooling medium are adjusted again by comparing the thermal field difference between the cooling element and the outer surface of the objective lens. Finally, the temperature of the third cooling medium and the flow rate required to form an air curtain are obtained by comparing the external ambient temperature and the temperature of the cooling element.

[0022] The beneficial effects of this invention are:

[0023] The present invention aims to achieve uniform objective lens surface temperature. It fully considers various factors that cause non-uniform objective lens temperature, such as geometric non-uniformity and non-uniform thermal resistance field formed by heat source non-uniformity. It achieves uniform objective lens surface temperature through three-layer cooling control.

[0024] The device employs multi-input multi-output zone independent control. By independently adjusting the temperature and flow rate of the three layers of cooling medium, as well as the flow rate and temperature of the first cooling medium at the inlet of each cooling module, a corresponding non-uniform cooling intensity field is formed, thereby achieving a high degree of uniformity in the surface temperature of the objective lens.

[0025] It achieves multi-layer collaborative control, combining rapid local fine-tuning with slow global adjustment, thereby improving the accuracy and response speed of temperature control.

[0026] The cooling channels inside each cooling module are designed differently according to the local geometry of the corresponding objective lens area and the expected heat load. Fractal channels can be used in local hot spots to ensure isothermal cooling inside the module and avoid secondary temperature gradients inside the module. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the multi-layered, region-divided lithography machine objective lens surface temperature control device in this embodiment;

[0028] Figure 2 Schematic diagram of the air supply structure for the third cooling medium;

[0029] Figure 3 This is a schematic diagram of the cooling modules and objective lens structures in the embodiment;

[0030] Figure 4 Used in the example Figure 1 The diagram shows a comparison of the temperature control effects of the device shown and existing methods.

[0031] In the diagram: 11. Cooling element; 111. Cooling module; 112. Miniature heat exchanger; 113. Flow regulating valve; 114. Flow sensor; 115. Temperature sensor installed on the inner wall of the cooling module; 12. Gap between cooling element and objective lens; 121. Independent air inlet; 13. Air supply assembly; 131. Static pressure chamber; 132. Annular air outlet; 2. Objective lens; 21. Local heat source of objective lens (such as sensors, actuators, etc. mounted on the objective lens); 22. Temperature sensor installed on the outer surface of the objective lens; 3. Host computer; 31. First cooling medium; 32. Second cooling medium; 33. Third cooling medium. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] like Figure 1 As shown, a multi-layered, regionalized lithography machine objective lens surface temperature control device includes a hollow cooling element 11, an air supply assembly 13, a miniature heat exchanger 112, a flow regulating valve 113, and a host computer 3. The cooling element 11 is coaxially mounted with the objective lens 2. The cooling element 11 is a cylindrical jacket surrounding the objective lens, typically coaxially positioned with the objective lens and leaving a gap between it and the outer surface of the objective lens. It is hollow inside and used for the flow of a first cooling medium 31. To address the problem of uneven heat source distribution in the objective lens 2, the cooling element 11 is designed with independent zones. The cooling element 11 consists of several independent cooling modules 111. The cooling channels within each cooling module 111 are independent and have independent inlets and outlets.

[0034] The host computer uses the temperature of the objective lens's outer surface as the control target. By combining the feedforward control of the lithography process, it adjusts the temperature and flow rate of the three-layer cooling medium and the temperature and flow rate of the first cooling medium input in different independent modules of the cooling element, forming a non-uniform cooling intensity field that matches the non-uniform heat source generated on the objective lens surface, thereby further improving the temperature uniformity of the lithography machine's objective lens surface.

[0035] Objective lenses are typically composed of multiple cylindrical layers of varying diameters. This embodiment uses a five-layer objective lens (the actual number of objective layers is usually more than five) corresponding to six cooling modules 111. In actual use, the number of cooling modules does not match the number of objective layers. The division of modules is based not only on geometric structure but, more preferably, on the thermophysical properties of the objective lens. For example, division can be made along isothermal or flow lines, or along the reinforcing ribs or bolt connection lines of the projection objective lens, to ensure minimal thermal stress. To prevent thermal interference between adjacent modules, the mating surfaces between modules are precision-machined and equipped with heat insulation layers or structures to minimize thermal short circuits between modules.

[0036] For localized areas with high heat loads or potential for sudden increases in heat load, independent cooling modules can be defined within these areas. The internal flow channels are designed as a multi-stage branching / merging distributed network structure. When the heat load in this localized area suddenly increases, the temperature of the first cooling medium flowing through it rises, its viscosity decreases, and the local flow resistance decreases. The flow spontaneously fine-tunes to increase the flow rate, thereby suppressing hot spots, homogenizing the temperature, and achieving isothermal cooling. Simultaneously, this structure better adapts to complex surface shapes and reduces cooling dead zones.

[0037] The number of cooling modules is determined based on actual usage, cost, and control precision requirements.

[0038] In this embodiment, the cooling element 11 includes six cooling modules 111 with independent internal flow channels. The six cooling modules 111 are stacked or spliced ​​and fixed to form the cooling element. A gap 12 is left between the inner surface of the cooling element and the outer surface of the objective lens sidewall. The joint surface of each cooling module is also provided with a heat insulation layer or heat insulation structure to minimize thermal short circuits between modules.

[0039] Each cooling module 111 has a first cooling medium 31 circulating inside it. In this embodiment, deionized water with high specific heat capacity and good thermal conductivity is used. In use, the temperature set value of the first cooling medium input to each cooling module 111 is usually lower than the target value for objective lens temperature control. Its main function is to serve as the core heat sink of the temperature control device, providing a constant and uniform low temperature boundary condition for objective lens temperature control.

[0040] The inner diameter of the cooling element 11 is designed to be larger than the outer diameter of the objective lens 2, forming a gap 12 of a certain thickness between the inner surface of the cooling element 11 and the outer surface of the projection objective lens 2. A second cooling medium 32 flows through this gap 12; in this embodiment, an inert gas with stable chemical properties and low thermal conductivity is used. This layer serves as a thermal buffer layer, its main function being to provide an inert, clean, and stable working environment for the objective lens 2 and its local heat sources 21 such as sensors and actuators, preventing oxidation and thermal disturbance. By adjusting the flow and temperature of this cooling medium, the heat flow distribution from the objective lens 2 to the cooling element 11 can be precisely controlled. Simultaneously, the slow thermal conductivity of the inert gas itself can filter out high-frequency, minute temperature fluctuations of the first cooling medium.

[0041] On the outer surface of the cooling element 11, an air supply assembly 13 is provided at the object end of the objective lens, forming an air curtain (third cooling medium 33) outside the cooling element 11 to eliminate the influence of external environmental temperature fluctuations on the temperature control device. In this embodiment, the third cooling medium 33 is clean air. By actively forming a flowing air curtain, the cooling element 11 (including the objective lens 2 located at the center) is actively isolated from the surrounding environment, effectively buffering disturbances such as temperature changes and pressure fluctuations in the external environment, and ensuring the stability of the internal temperature control system.

[0042] The first cooling medium 31 is distributed to each cooling module 111 via a flow divider. An ultra-compact, fast-response miniature heat exchanger 112 is installed at the cooling medium inlet of each cooling module 111, and a high-precision flow regulating valve 113 and a flow meter 114 are installed at the cooling medium outlet of each cooling module 111. The heat exchanger and the flow regulating valve are controlled by a host computer 3, which rapidly fine-tunes the temperature and flow rate of the first cooling medium flowing into each cooling module 111. This avoids frequent changes in the set temperature of the first cooling medium flowing into each cooling module when the local temperature of the objective lens changes (e.g., when a local heat source generates heat). The high-precision flow regulating valve and flow meter can independently and accurately control the flow rate of the first cooling medium to each cooling module. For areas with high heat load or poor heat dissipation conditions (e.g., thick gaps), a larger flow rate can be allocated to enhance cooling intensity.

[0043] The second cooling medium 32 enters the gap 12 between the cooling element 11 and the objective lens 2 through multiple independent air inlets 121. These air inlets are distributed circumferentially or axially to ensure regional stability. A flow equalization device is provided at the air inlets 121 to ensure that the second cooling medium is evenly distributed when it enters the gap 12, which is conducive to forming a stable initial laminar flow field and avoids turbulence that could cause vibration.

[0044] Along the axis of objective lens 2, one or more cooling elements such as... are provided on the top of cooling element 11 (objective end of objective lens). Figure 2The air supply assembly 13 shown has an air outlet 132 arranged in a ring around the outer periphery of the cooling element 11, forming an air curtain on the outer surface of the cooling element 11. After the third cooling medium 33 has its temperature, flow rate, and pressure regulated by an external heat exchanger, flow regulating valve, and pressure regulating valve, it first enters a static pressure chamber 131 for pressure stabilization and uniform flow, and then is evenly supplied through the annular air outlet 132, thereby forming an air curtain to isolate environmental fluctuations.

[0045] The host computer 3 first compares the real-time temperature monitoring value PV of the objective lens. PO and target temperature SV PO (Typically 22℃) The temperature and flow rate setpoints of the first cooling medium are calculated. The temperature and flow rate of the first cooling medium are adjusted through an external heat exchanger and flow control valve to reach the setpoints before flowing into each cooling module via a flow divider. Next, the equivalent thermal resistance and heat flux density of the gap 12 in each cooling module are estimated in real time by comparing the temperature detected by the temperature sensor 115 on the inner wall of each cooling module with the temperature detected by the temperature sensor 22 on the objective lens frame of the corresponding area. Based on the comparison of the equivalent thermal resistance and heat flux density with the target temperature, the temperature control target to be achieved by each cooling module 111 is obtained. Then, the temperature and flow rate of the first cooling medium flowing into each cooling module are locally fine-tuned through the miniature heat exchanger 112 and flow control valve 113 of each cooling module. The thermal field difference between the cooling element 11 and the outer surface of the objective lens is compared again, and the flow rate of the second cooling medium is adjusted through an external flow control valve. Finally, by monitoring the external ambient temperature and the temperature of the cooling element, the temperature of the third cooling medium and the flow rate required to form an air curtain are obtained. The temperature and flow rate of the third cooling medium 33 are adjusted through an external heat exchanger and flow control valve.

[0046] like Figure 3 As shown, the gap δ1 between the objective lens layers L1, L3, and L5 and the inner wall of the cooling element is smaller than the gap δ2 between the L2 and L4 layers and the inner wall of the cooling element. If the existing method is used, the surface temperature of the L2 and L4 layers will be significantly higher than that of the L1, L3, and L5 layers. The multi-layer structure of the temperature control device of the present invention can significantly improve the problem of temperature unevenness caused by structural inhomogeneity.

[0047] First, based on the different gaps δ between the objective lens and the cooling element, the cooling element is divided along the axis into six independent temperature control modules A, B, C, D (including D-1 and D-2), and E, corresponding to layers L1 to L5 of the objective lens, respectively. Each cooling module 111 is equipped with a separate first cooling medium circuit, and a miniature heat exchanger 112 and a flow regulating valve 113 are arranged on the circuit. In use, the host computer controls the miniature heat exchanger 112 and the flow regulating valve 113 in modules A, C, and E, so that the flow rate of the first cooling medium in modules A, C, and E is slightly greater than that in modules B and D, thereby eliminating the influence of the difference between gaps δ1 and δ2 on the uniformity of the cooling effect.

[0048] The sensors, actuators, and electronic circuits integrated on the objective lens frame also generate heat during operation, forming a non-uniform heat source on the objective lens surface, which also affects the temperature uniformity of the objective lens surface. Taking the temperature control of regions D-1 and D-2 corresponding to layer L4 as an example, the heat generated by layer L4 and a local heat source 21 on it during operation will cause the temperature of the objective lens surface in the surrounding area to rise, and the affected objective lens surface area is region L4-1. The other unaffected areas of this objective lens layer are region L4-2. Correspondingly, the cooling element 11 and the cooling module D corresponding to this layer on the objective lens are further divided into two independent cooling models D-1 and D-2, whose positions correspond to regions L4-1 and L4-2 on the objective lens surface, respectively. When the local heat source generates heat, the host computer controls the flow rate of the first cooling medium in region D-1 to increase. If the heat generation is large, the micro heat exchanger can also be adjusted to slightly lower the temperature of the first cooling medium in region D-1, enhancing the cooling capacity of region D-1 and thus eliminating the influence of local heat source on region L4-1, ensuring the uniformity of the objective lens surface temperature.

[0049] The specific temperature control process is as follows:

[0050] 1) Sensor input: At time t, the temperature of region L4-1 of the objective lens is T. L4-1 The temperature in region L4-2 is T L4-2 The inlet temperature of the first cooling medium is T. D1 The flow rate is Q D1 The inlet temperature of the second cooling medium is T. D2 The flow rate is Q D2 ;

[0051] 2) Process feedforward: At time t+t1, the heat source in region L4-1 will increase by ΔP; if no measures are taken, the temperature in region L4-1 will rise; if the temperature / flow rate of the first cooling medium outlet of the first cooling medium control unit is adjusted to ensure the temperature in region L4-1, the temperature in regions L1~3, L4-2 and L5 will decrease.

[0052] 3) Design constraints: the set range of the inlet temperature of the first cooling medium, the rate of change of the flow rate of module D-1, and the rate of change of the power of the micro heat exchanger of module D-1;

[0053] 4) Model Solution: During the time interval t~t+t1, the photolithography process determines the magnitude of ΔP. If ΔP < P (determined by the flow rate change rate of cooling element D-1), the opening of the module flow regulating valve of the corresponding cooling element in region L4-1 is gradually increased from k to k”. If ΔP ≥ P, the opening of the module flow regulating valve of the corresponding cooling element in region L4-1 is gradually increased from k to k”, and the cooling power of the micro heat exchanger is gradually increased from R to R”. At time t+t1+1, the inlet temperature of the second cooling medium is adjusted to T2”. At time t+t1+2~t+t2, the inlet flow rate of the second cooling medium is adjusted to Q2”.

[0054] 4) Execution output: Execute the solution at time t+1, that is, adjust the opening of the module flow regulating valve of the corresponding cooling element in region L4-1 to k', and increase the cooling power of the micro heat exchanger to R' (if any), while keeping other parameters at their current values;

[0055] 5) Recalculate at time t+1 and repeat the above process.

[0056] 6) Throughout the entire temperature control process, the outlet temperature of the third cooling medium remains consistent with the objective lens temperature control target value.

[0057] In the above process, by controlling the temperature and flow of the second cooling medium layer, the conductive thermal resistance between the objective lens and the cooling element can be converted into convective thermal resistance, further reducing the impact of the difference between gaps δ1 and δ2 on the uniformity of the cooling effect. Enclosing the objective lens and temperature control device within a temperature-stable and uniform local air bath (the third cooling medium layer) isolates the objective lens temperature from the influence of ambient temperature fluctuations and inhomogeneities, thus effectively improving the uniformity of the objective lens surface temperature. This demonstrates that the multi-layer zoned temperature control device achieves independent zoned control through multi-input multi-output, while simultaneously implementing feedforward control based on a physical model in conjunction with the photolithography process, thereby improving the accuracy and response speed of temperature control.

[0058] like Figure 4 As shown, compared with existing methods, the multi-layered, zoned temperature control device significantly improves the uniformity of the objective lens surface temperature. Existing methods only arrange a serpentine or spiral-shaped pipe on the outer surface of the objective lens, with a cylindrical jacketed cooling element containing cooling water, and an external set of inlets and outlets. The improvement is achieved by comparing the real-time temperature monitoring value PV of the objective lens. PO and target temperature SV PO (Typically 22℃), the inlet temperature of the cooling water is adjusted in real time to ensure the stability of the objective lens's outer surface temperature. The main problem with this temperature control scheme is that it cannot completely eliminate the spatial non-uniformity of the objective lens's outer surface temperature caused by the thermal resistance of the air gap due to uneven thickness between the objective lens and the water jacket (cooling element). Using the device described in this invention for temperature control can significantly improve the problem of temperature non-uniformity caused by the non-uniformity of the objective lens's surface structure.

Claims

1. A multi-layered, region-divided lithography machine objective lens surface temperature control device, characterized in that: The system includes a cooling element, an air supply assembly, a miniature heat exchanger, a flow control valve, and a host computer mounted on the outer wall of the objective lens. The cooling element comprises multiple layers of cooling modules with independent internal flow channels. These multiple cooling modules are divided into regions based on the geometry and thermophysical properties of the objective lens. The multiple cooling modules are stacked or spliced ​​together to form the cooling element, with a gap between the inner wall of the cooling element and the outer wall of the objective lens. Multiple air inlets are also provided on the cooling element. One or more air supply assemblies are mounted along the objective lens axis at the objective end, forming an air curtain on the outer surface of the cooling element. Each cooling module has a temperature sensor installed on its inner wall, and the objective lens also has a temperature sensor installed on its outer wall. A first cooling medium flows through the internal flow channel of the cooling element, a second cooling medium flows through the gap between the inner wall of the cooling element and the outer wall of the objective lens, and the air curtain is an isolation layer formed by a third cooling medium between the outer wall of the cooling element and the external environment. Each cooling module is equipped with a miniature heat exchanger at the first cooling medium inlet and a flow regulating valve and flow meter at the first cooling medium outlet of each cooling module. The host computer controls the temperature and flow rate of the first, second, and third cooling media flowing into the system. Simultaneously, it uses the temperature collected by various temperature sensors to control the micro heat exchanger and flow regulating valve to fine-tune the temperature and flow rate of the first cooling media, and to dynamically regulate the temperature and flow rate of the second and third cooling media.

2. The multi-layered, regionalized lithography machine objective lens surface temperature control device as described in claim 1, characterized in that: The first cooling medium is deionized water with high specific heat capacity and good thermal conductivity; the temperature set value of the first cooling medium flowing into each cooling module is lower than the target value for objective lens temperature control.

3. The multi-layered, regionalized lithography machine objective lens surface temperature control device as described in claim 1, characterized in that: The second cooling medium is an inert gas with stable chemical properties and low thermal conductivity.

4. The multi-layered, regionalized lithography machine objective lens surface temperature control device as described in claim 1, characterized in that: The third cooling medium is clean air.

5. The multi-layered, regionalized lithography machine objective lens surface temperature control device as described in claim 1, characterized in that: The multiple air inlets are distributed circumferentially or axially, and a flow equalization device is provided at the air inlets.

6. The multi-layered, regionalized lithography machine objective lens surface temperature control device as described in claim 1, characterized in that: The air outlet of the air supply assembly is arranged in a ring around the outer periphery of the cooling element, forming an air curtain on the outer surface of the cooling element.

7. The multi-layered, regionalized lithography machine objective lens surface temperature control device as described in claim 1, characterized in that: The third cooling medium first enters a static pressure chamber for pressure stabilization and uniform flow, and then is evenly distributed through an annular air outlet to form an air curtain.

8. The multi-layered, regionalized lithography machine objective lens surface temperature control device as described in claim 1, characterized in that: The cooling modules are set along the reinforcing ribs and bolt connection lines of the projection lens, and each cooling module's joint surface is also provided with a heat insulation layer or heat insulation structure.

9. The multi-layered, regionalized lithography machine objective lens surface temperature control device as described in claim 1, characterized in that: For local areas with high heat load or potential for sudden increases in heat load, independent cooling modules are defined. The internal flow channels of these cooling modules are designed as a multi-level branching / merging distributed network structure.

10. The multi-layered, regionalized lithography machine objective lens surface temperature control device as described in claim 1, characterized in that: The host computer calculates the temperature and flow rate settings of the first cooling medium by comparing the real-time temperature monitoring value of the objective lens surface with the target temperature. It then estimates the equivalent thermal resistance and heat flux density of the gap in the corresponding area by comparing the temperature detected by the temperature sensors on the inner wall of each cooling module with the temperature detected by the temperature sensors on the outer wall of the objective lens. Based on the comparison of the equivalent thermal resistance and heat flux density with the target temperature, the temperature control target to be achieved by each cooling module is obtained. The temperature and flow rate of the first cooling medium flowing into each cooling module are then finely adjusted locally using the miniature heat exchangers and flow regulating valves of each cooling module. Next, the temperature and flow rate of the second cooling medium are adjusted by comparing the thermal field difference between the cooling element and the outer surface of the objective lens. Finally, the temperature of the third cooling medium and the flow rate required to form an air curtain are obtained by comparing the external ambient temperature and the temperature of the cooling element.

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