A method of heat control of a patterning device

Abstract

The present disclosure provides a heat control method of a pattern forming device, comprising: S1, turning on compensation illumination, heating the pattern forming device to a thermal equilibrium temperature interval, and then turning off the compensation illumination; the illumination area of the compensation illumination is S C1×C2 ; S2, turning on first detection illumination, and turning off the first detection illumination after a detection step is completed; the illumination area of the first detection illumination is S D1×D2 ; S3, turning on exposure illumination, and turning off the exposure illumination after an exposure step is completed; the illumination area of the exposure illumination is S E1×E2 ; wherein, S C1×C2 ≥ S D1×D2 ≥ S E1×E2 ; during the mutual switching of S1, S2 and S3, the temperature of the pattern forming device is maintained in the thermal equilibrium temperature interval; within the thermal equilibrium temperature interval, the edge Z-direction deformation amount of the compensation illumination region ΔΔZ C1×C2 is greater than or equal to 50% of the Z-direction deformation amount ΔZ of the center of the pattern forming device. The present disclosure realizes long-time maintenance of the thermal equilibrium of the pattern forming device by introducing the compensation illumination, so that the pattern of the pattern forming device can maintain stable deformation.

Description

Technical Field

[0001] This disclosure relates to the field of thermal control technology, and more specifically to a thermal control method for a pattern forming apparatus. Background Technology

[0002] Under illumination, some incident light is absorbed by the pattern forming device (such as a template), causing the template temperature to rise and resulting in thermal deformation. Template thermal deformation includes XY-plane deformation and Z-direction deformation. XY-plane deformation leads to template pattern positional shift, a major source of overlay error; Z-direction deformation affects the flatness of the template surface and also impacts the control of the template's focal plane. XY-plane deformation can be corrected by applying external force to the template's edges, while Z-direction deformation cannot be corrected by applying external force to the surface. Therefore, controlling the amount of deformation in the Z-direction is particularly important.

[0003] In projection exposure, a series of thermal control methods are mainly used to control the thermal deformation of the template, including designing a nitrogen supply system inside the mirror assembly and a water-cooling structure for the template stage to improve heat dissipation. Traditional near-field exposure, however, has low exposure resolution and does not have special requirements for template temperature control, allowing it to operate in a laboratory environment. But when the distance between the template and the substrate is only a few hundred nanometers or less, or even in contact, traditional thermal control methods cannot be applied. Therefore, controlling the Z-axis thermal deformation of the template becomes a pressing problem to be solved. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] To address the aforementioned issues, this disclosure provides a thermal control method for a pattern forming apparatus, which solves the technical problem that traditional methods struggle to achieve effective thermal control of the pattern forming apparatus when the distance between the pattern forming apparatus and the substrate is only a few hundred nanometers or less.

[0006] (II) Technical Solution

[0007] This disclosure provides a thermal control method for a pattern forming apparatus, comprising: S1, turning on the compensation illumination, heating the pattern forming apparatus to a thermal equilibrium temperature range, and then turning off the compensation illumination; the area of ​​the illumination region of the compensation illumination is S. C1×C2 S2, turn on the first detection illumination, and turn off the first detection illumination after the detection step is completed; the area illuminated by the first detection illumination is S. D1×D2 S3, turn on the exposure lighting, and turn it off after the exposure step is complete; the area illuminated by the exposure lighting is S. E1×E2 Among them, S C1×C2 ≥S D1×D2 ≥S E1×E2During the switching process between S1, S2, and S3, the temperature of the pattern forming device is maintained within the thermal equilibrium temperature range; within the thermal equilibrium temperature range, the Z-direction deformation ΔZ at the edge of the compensated illumination area is reduced. C1×C2 It is greater than or equal to 50% of the deformation ΔZ in the Z direction of the center of the pattern forming device.

[0008] Furthermore, before S1, there is also S0, which determines the thermal equilibrium temperature range based on the relationship between the deformation of the pattern forming apparatus and the temperature.

[0009] Furthermore, after S3, it also includes: S4, in the next exposure field, turning on the exposure illumination, and during the exposure illumination period, the temperature of the pattern forming apparatus is maintained within the thermal equilibrium temperature range; the time interval between turning on the exposure illumination before and after the exposure field is T5.

[0010] Furthermore, before S4, there is also: S41, turning off all lighting to allow the pattern forming apparatus to cool down for a duration of T4; T4 may include T5 or T4 may not include T5.

[0011] Furthermore, after S3, the process includes repeating S2 to S3, alternating between the detection and exposure steps, with the pattern forming apparatus maintaining a thermal equilibrium temperature range during the detection and exposure steps.

[0012] Furthermore, S1 also includes: while turning on the compensation lighting, turning on the second detection lighting, and in S2 to S3, the second detection lighting remains on; the heat output power of the second detection lighting is much smaller than the heat output power of the first detection lighting, and there is no interference between the second detection lighting and the first detection lighting.

[0013] Furthermore, after S3, the following steps are also included: S41, turning off all illumination to allow the pattern forming apparatus to cool down for a duration of T4; S4, in the next exposure field, turning on the exposure illumination, during which the temperature of the pattern forming apparatus is maintained within the thermal equilibrium temperature range; the time interval between turning on the pre- and post-exposure illumination is T5; wherein, T4 includes T5 or T4 does not include T5.

[0014] Furthermore, after S3, the process includes repeating S2 to S3, alternating between the detection and exposure steps, with the pattern forming apparatus maintaining a thermal equilibrium temperature range during the detection and exposure steps.

[0015] Furthermore, S2 includes: alternately turning on the third detection illumination and the first detection illumination, wherein the single illumination cycle and single illumination duration of the third detection illumination match the single illumination cycle and single illumination duration of the first detection illumination; wherein there is interference between the third detection illumination and the first detection illumination.

[0016] Furthermore, after S3, the process includes: repeating S2 to S3, during which only the third detection illumination is turned on in S2 and the first detection illumination is turned off; alternating between the detection step and the exposure step, and maintaining the pattern forming apparatus in the thermal equilibrium temperature range during the detection step and the exposure step.

[0017] (III) Beneficial Effects

[0018] The thermal control method for the pattern forming apparatus disclosed herein introduces compensating illumination in addition to detection illumination and exposure illumination. This ensures that the temperature of the pattern forming apparatus remains within the thermal equilibrium temperature range when switching between illumination modes, resulting in minimal temperature fluctuations. This allows the pattern forming apparatus to maintain thermal equilibrium for an extended period, enabling it to maintain uniform and stable deformation in the Z-axis. Furthermore, by rationally allocating the timing of each illumination mode and appropriately matching the light intensity, frequency, and cooling time of different illumination sources, switching between illumination modes is achieved, thereby improving exposure efficiency. Attached Figure Description

[0019] Figure 1 A flowchart illustrating a thermal control method for a pattern forming apparatus according to an embodiment of the present disclosure is shown schematically.

[0020] Figure 2 A schematic diagram of the structure of an exposure system according to an embodiment of the present disclosure is shown.

[0021] Figure 3 The diagram illustrates the energy transfer process in the pattern forming apparatus according to an embodiment of the present disclosure.

[0022] Figure 4 The diagram illustrates the timing switching process of various lights in the first embodiment of the present disclosure;

[0023] Figure 5 A schematic top view of a pattern forming apparatus according to an embodiment of the present disclosure is shown;

[0024] Figure 6 The diagram illustrates the timing switching process of various lights in the second embodiment of the present disclosure;

[0025] Figure 7 The diagram illustrates the timing switching process of various lighting systems according to the third embodiment of this disclosure.

[0026] Figure 8 The diagram illustrates the timing switching process of various lighting systems according to the fourth embodiment of this disclosure.

[0027] Figure 9 The diagram illustrates the timing switching process of various lights according to the fifth embodiment of this disclosure;

[0028] Figure 10 The diagram illustrates the timing switching process of various lights according to the sixth embodiment of this disclosure;

[0029] Figure 11 The diagram illustrates the timing switching process of various lighting systems according to the seventh embodiment of this disclosure.

[0030] Figure 12 A schematic diagram illustrating the timing switching process of various lighting systems according to Embodiment 1 of this disclosure is shown.

[0031] Figure 13 A top view of the pattern forming apparatus according to Embodiment 1 of the present disclosure is shown schematically;

[0032] Figure 14 This schematic diagram illustrates the temperature change of the pattern forming apparatus according to Embodiment 1 of the present disclosure;

[0033] Figure 15 This schematic diagram illustrates the temperature changes of a pattern forming apparatus when the thermal control method of this disclosure is not employed.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1. Pattern forming apparatus; 1-1. First air layer; 1-2. Substrate of pattern forming apparatus; 1-3. Pattern film layer; 1-4. Second air layer; 1-5. First boundary layer; 1-6. Absorption layer; 1-7. Second boundary layer; 2. Suction cup; 3. Substrate; 4. Stage; 5-1-1. Second detection illumination; 5-1-2. Third detection illumination; 5-2. First detection illumination; 5-3. Exposure illumination; 5-4. Compensation illumination. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0037] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0038] It should be noted that if the embodiments of this disclosure involve directional indication, the directional indication is only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0039] The use of ordinal numbers such as "first," "second," "third," etc., in the specification and claims to modify the corresponding elements does not in itself imply or represent any ordinal number of the element, nor does it represent the order of one element with another element, or the order of manufacturing methods. The use of these ordinal numbers is only to enable a clearly distinguishable element with a certain name from another element with the same name.

[0040] This disclosure provides a thermal control method for a pattern forming apparatus. Please refer to [link to relevant documentation]. Figure 1 The process includes: S1, turning on the compensation illumination 5-4, heating the pattern forming apparatus 1 to the thermal equilibrium temperature range, and then turning off the compensation illumination 5-4; the area of ​​the illumination region of the compensation illumination 5-4 is S. C1×C2 S2, turn on the first detection illumination 5-2, and turn off the first detection illumination 5-2 after the detection step is completed; the illumination area of ​​the first detection illumination 5-2 is S. D1×D2 S3, turn on exposure illumination 5-3, and turn off exposure illumination 5-3 after the exposure step is completed; the area illuminated by exposure illumination 5-3 is S. E1×E2 Among them, S C1×C2 ≥S D1×D2 ≥S E1×E2 During the switching process between S1, S2, and S3, the temperature of the pattern forming apparatus 1 is maintained within the thermal equilibrium temperature range; within the thermal equilibrium temperature range, the Z-direction deformation ΔZ at the edge of the illumination area is compensated. C1×C2 It is greater than or equal to 50% of the deformation ΔZ in the Z direction of the center of the pattern forming device.

[0041] The thermal control method disclosed herein can be applied to exposure equipment such as contact exposure, proximity exposure, or near-field exposure. For example, ... Figure 2 As shown, in the near-field exposure system, the pattern forming apparatus 1 is adsorbed and mounted on the suction cup 2, and the substrate 3 is mounted on the stage 4. The pattern forming apparatus 1 is affected by the thermal load of the first detection illumination 5-2, the exposure illumination 5-3, and the compensation illumination 5-4. The first detection illumination 5-2 is used to acquire position information, the exposure illumination 5-3 is used to provide the light required for exposure, and the compensation illumination 5-4 is used to heat the pattern forming apparatus 1, allowing it to quickly reach thermal equilibrium. The compensation illumination 5-4 can be an additional illumination system or the existing first detection illumination 5-2. For ease of explanation, the illumination used to perform the function of heating the pattern forming apparatus 1 is referred to as the compensation illumination 5-4. Since the distance between the pattern forming apparatus 1 and the substrate 3 is only a few hundred nanometers or less, or even in contact, a heat dissipation system cannot be designed below the pattern forming apparatus 1. To maximize the heat dissipation capacity of the pattern forming apparatus, the suction cup 2 is made of a material with high rigidity and low coefficient of thermal expansion, preferably microcrystalline glass, silicon carbide, or alumina.

[0042] like Figure 3 As shown, in the illumination area, the pattern forming apparatus 1 is positioned above a first air layer 1-1, and the pattern forming apparatus 1 consists of a pattern forming apparatus substrate 1-2 and a pattern film layer 1-3. Below the pattern forming apparatus 1 is a second air layer 1-4. The heat absorption region can be divided into a first boundary layer 1-5, an absorption layer 1-6, and a second boundary layer 1-7. The first boundary layer 1-5 is the interface between the pattern forming apparatus substrate 1-2 and the first air layer 1-1, with a heat absorption rate of A% and a heat return rate of B%. The absorption layer 1-6 is the pattern forming apparatus substrate 1-2, with a heat absorption rate of C%. Since the pattern film layer 1-3 is only tens to hundreds of nanometers thick, the second boundary layer 1-7, including the pattern film layer 1-3, is the interface between the pattern forming apparatus substrate 1-2 and the second air layer 1-4, with a heat absorption rate of D% and a heat absorption rate of E%. The sum of A%, B%, C%, D%, and E% is 100%.

[0043] Exposure imaging simulation analysis shows that a significant proportion of heat is reflected back to the first air layer 1-1 (i.e., a large B value); the substrate 1-2 of the pattern forming apparatus has high transmittance and absorbs very little heat (i.e., a small C value); the heat absorption of the pattern forming apparatus 1 is mainly concentrated in the pattern film layer 1-3 (i.e., a large D value). At room temperature, the thermal conductivity of the absorption layer 1-6 is 1.3 W / (m·℃), but with exposure times of only seconds or less, heat cannot be transferred in time to the first boundary layer 1-5 between the substrate 1-2 and the first air layer 1-1; the heat exchange between the pattern forming apparatus 1 and the substrate 3 at a spacing of hundreds of nanometers is achieved through contact with air, with a heat transfer coefficient as low as 5 × 10⁻⁶. -6 W / (mm 2 Because the temperature is below ℃, most of the heat on the lower surface of the pattern forming apparatus 1 can only be slowly transferred to the upper surface. Since the heat cannot be dissipated in time, a heat balance method is used to control the heat. The heat balance method maintains the temperature of the pattern forming apparatus 1 within a small range by switching between different illuminations at different times. This results in a smaller difference in the Z-direction deformation between the center and edge positions of the pattern forming apparatus 1 after overall thermal deformation, and a smaller degree of deterioration in the overall surface undulation. This avoids positional errors caused by uneven Z-direction deformation and unpredictable and excessive deformation of the processed pattern.

[0044] This thermal control method starts from the heat source and introduces compensation lighting 5-4 on top of the first detection lighting 5-2 and exposure lighting 5-3. This causes the temperature of the pattern forming device 1 (e.g., the template) to rise rapidly to the thermal equilibrium temperature range. Within this range, the pattern forming device 1 is in thermal equilibrium, achieving continuous, uniform, and stable Z-axis deformation. This avoids the large deformation fluctuations that occur when the pattern forming device 1 is not controlled during subsequent detection and exposure, which would lead to excessive deviations in the pattern's position during detection and exposure. This disclosure enables the pattern forming device 1 to maintain thermal equilibrium for an extended period, ensuring uniform and stable deformation of the pattern. It provides an effective thermal control method that meets the temperature gradient difference and surface shape influence control requirements for exposure. Furthermore, by rationally allocating the timing of each lighting mode and matching the light intensity, frequency, and cooling time of different light sources, switching between lighting modes is achieved, improving exposure efficiency.

[0045] Based on the above embodiment, before S1, there is also: S0, determining the thermal equilibrium temperature range according to the relationship between the deformation of the pattern forming apparatus 1 and the temperature.

[0046] First, determine the thermal equilibrium temperature range W of the pattern forming apparatus 1. The pattern forming apparatus 1 deforms under heat, and the relationship between the deformation and temperature can be obtained experimentally or through simulation. When, within a certain temperature range, the deformation in the Z-direction at the edge of the pattern forming apparatus 1 is greater than or equal to 50% of the deformation in the Z-direction at the center, this temperature range can be taken as the thermal equilibrium temperature range W. To more effectively utilize the compensation lighting energy, compensation lighting is usually not applied to the entire area of ​​the pattern forming apparatus 1. Therefore, the area of ​​the compensation lighting area is usually smaller than the area of ​​the pattern forming apparatus 1. In this case, the thermal equilibrium temperature range W is the Z-direction deformation ΔZ at the edge of the compensation lighting area. C1×C2 The temperature range corresponding to 50% or greater than or equal to the deformation ΔZ in the Z direction of the center of the pattern forming device.

[0047] In the following schematic diagrams of timing switching processes, the duration and power density are for illustrative purposes only and should not be construed as limiting actual values.

[0048] After determining the thermal equilibrium temperature range W, as follows Figure 4As shown in the first scheme, continuing with step S1, the following steps are included: simultaneously turning on the power-on device and activating the compensation illumination 5-4. The illumination area of ​​the compensation illumination 5-4 is C1×C2, the power density is P3, and the illumination time is T1. The illumination continues until the pattern forming apparatus 1 reaches the thermal equilibrium temperature range W, and then the compensation illumination 5-4 is turned off. The compensation illumination 5-4 is used to heat the pattern forming apparatus 1 at room temperature to the thermal equilibrium temperature range W, preventing excessive difference in deformation between the center and edge of the detection area when the first detection illumination 5-2 is subsequently introduced, as the temperature of the pattern forming apparatus 1 is not controlled.

[0049] Step S2 includes: turning on the first detection illumination 5-2, the illumination area of ​​the first detection illumination 5-2 is D1×D2, the power density is P4, the single illumination cycle is T, the single illumination duration is U2, the detection time in a single field detection is T2, and after the single field illumination time reaches T2, the position information detection is completed, and the first detection illumination 5-2 is turned off. During operation, the first detection illumination 5-2 maintains the temperature of the pattern forming apparatus 1 within the thermal equilibrium temperature range.

[0050] Step S3 includes: turning on the exposure illumination 5-3, the illumination area of ​​the exposure illumination 5-3 is E1×E2, the power density is P5, the single-field illumination time is T3, and after the single-field illumination time reaches T3, the exposure is completed, and the exposure illumination 5-3 is turned off. During the switching process between the first detection illumination 5-2 and the exposure illumination 5-3, and in step S3, the temperature of the pattern forming apparatus 1 is maintained within the thermal equilibrium temperature range.

[0051] The top view of the pattern forming apparatus 1 is as follows: Figure 5 As shown, C1×C2 is the compensation illumination area of ​​the pattern forming apparatus 1, the area of ​​D1×D2 has test marks processed, and E1×E2 is the graphic surface area of ​​the pattern forming apparatus 1. C1×C2 ≥S D1×D2 ≥S E1×E2 (S C1×C2 S represents the area of ​​the region C1×C2. D1×D2 S represents the area of ​​the region D1×D2. E1×E2 This represents the area of ​​region E1×E2. The area of ​​the illumination region of the compensation lighting 5-4 is the largest (when the first detection lighting 5-2 is used as the compensation lighting, the area of ​​the illumination region of the compensation lighting 5-4 is equal to the area of ​​the illumination region of the first detection lighting 5-2). Therefore, the compensation lighting can uniformly heat the pattern forming device 1, making the temperature within the compensation lighting region more uniform, all within the thermal equilibrium temperature range W.

[0052] Based on the above embodiment, after S3, it further includes: S4, after moving the substrate 3 to the next exposure field, turning on the exposure illumination 5-3, and during the illumination of the exposure illumination 5-3, the temperature of the pattern forming apparatus 1 is maintained within the thermal equilibrium temperature range; the time interval between the two exposure illuminations is T5.

[0053] The stage 4 moves the substrate 3 to the next exposure field for the next exposure, activating the next exposure illumination. This process continues, switching exposure illumination as needed to ensure that the energy output to the pattern forming apparatus 1 within a unit time of the new exposure illumination is consistent with the previous method. The time interval between activating the upper and lower exposure illuminations 5-3 is T5, which is the field switching time. Due to the poor heat exchange effect between the pattern forming apparatus 1 and the air, the temperature change is minimal within the field switching time T5. If the pattern forming apparatus 1 needs to be replaced, step S1 must be returned to. Since the temperature of the newly replaced pattern forming apparatus is room temperature, the compensating illumination 5-4 needs to be used again to heat the pattern forming apparatus 1 to the thermal equilibrium temperature range.

[0054] Based on the above embodiment, before S4, it further includes: S41, turning off all lighting to allow the pattern forming apparatus 1 to cool down for a cooling time of T4; T4 may include T5 or T4 may not include T5.

[0055] Ideally, the temperature will not jump during the switching between the first detection illumination 5-2 and the exposure illumination 5-3, meaning the temperature will remain within the thermal equilibrium temperature range W. However, because the exposure illumination time T3 is relatively long to ensure the effective development of the pattern after exposure, the energy output from the exposure illumination 5-3 to the pattern forming apparatus 1 is greater. At this point, the temperature of the pattern forming apparatus 1 will rise to near the upper limit of the thermal equilibrium temperature range. Therefore, to prevent the temperature from exceeding the upper limit of the thermal equilibrium temperature range during the next exposure, a cooling process can be added after the exposure step to lower the temperature and deviate it from the upper limit of the thermal equilibrium temperature range. During this cooling process, all illumination is turned off. Specifically, a cooling step S41 is added after step S3. Step S4 can be performed after this cooling step, or it can be performed during the cooling process itself, meaning cooling and moving to the next exposure field occur simultaneously. The timing switching process is as follows: Figure 6 As shown in the second scheme, all lighting is turned off, and the cooldown time is T4.

[0056] Based on the above embodiment, after S3, the method further includes: repeating S2 to S3, alternating between the detection step and the exposure step, and maintaining the pattern forming apparatus 1 in the thermal equilibrium temperature range during the detection step and the exposure step.

[0057] In the above embodiments, the single-block pattern forming apparatus 1 can perform multiple exposures after only one position detection. If a detection is required for the next exposure after the single exposure, it is necessary to return to step S2 after step S3 (or step S41 if it exists). The timing switching process is as follows: Figure 7 As shown (third option).

[0058] Based on the above embodiment, S1 further includes: while turning on the compensation illumination 5-4, turning on the second detection illumination 5-1-1. In S2 to S3, the second detection illumination 5-1-1 is kept on. The heat output power of the second detection illumination 5-1-1 is much smaller than the heat output power of the first detection illumination 5-2. That is, the heat input to the pattern shape device 1 by the second detection illumination 5-1-1 has basically no effect on its surface shape. Moreover, there is no interference between the second detection illumination 5-1-1 and the first detection illumination 5-2. That is, whether the second detection illumination 5-1-1 is on or off does not affect the detection effect of the first detection illumination 5-2.

[0059] Based on the first scheme, to expand the applicable scenarios of the above-mentioned thermal control method, the detection lighting with different detection functions is divided into a first detection lighting 5-2 with high heat output power and a second detection lighting 5-1-1 with low heat output power, according to the different heat input. Since the second detection lighting 5-1-1 with low heat output power has little effect on the thermal deformation of the pattern forming device 1, this lighting can be kept on continuously, and is called continuous detection lighting. See Figure 8 The complete process is as follows:

[0060] Step S1 includes: turning on the second detection illumination 5-1-1 and the compensation illumination 5-4 simultaneously. The second detection illumination 5-1-1 outputs less heat to the pattern forming device 1, and its illumination area can be determined according to actual needs. The compensation illumination 5-4 has an illumination area of ​​C1×C2, a power density of P3, and an illumination time of T1. The illumination continues until the pattern forming device 1 reaches the thermal equilibrium temperature range W, and then the compensation illumination 5-4 is turned off.

[0061] Step S2 includes: turning on the first detection illumination 5-2, the illumination area of ​​the first detection illumination 5-2 is D1×D2, the power density is P4, the single illumination cycle is T, the single illumination duration is U2, the detection time in a single field detection is T2, and after the single field illumination time reaches T2, turning off the first detection illumination 5-2. During operation, the first detection illumination 5-2 maintains the temperature of the pattern forming apparatus 1 within the thermal equilibrium temperature range.

[0062] Step S3 includes: turning on the exposure illumination 5-3, the illumination area of ​​the exposure illumination 5-3 is E1×E2, the power density is P5, the single-field illumination time is T3, and after the single-field illumination time reaches T3, turning off the exposure illumination 5-3. During the switching process between the first detection illumination 5-2 and the exposure illumination 5-3, and in step S3, the temperature of the pattern forming apparatus 1 is maintained within the thermal equilibrium temperature range.

[0063] Based on the above embodiment, after S3, it further includes: S4, after moving the substrate 3 to the next exposure field, turning on the exposure illumination 5-3, the energy output to the pattern forming apparatus 1 during the illumination of the exposure illumination 5-3 is the same as the energy output to the pattern forming apparatus 1 in the previous exposure field; the time interval between the two exposure illuminations is T5, which is the field switching time.

[0064] Ideally, the temperature will not jump during the switching between the first detection illumination 5-2 and the exposure illumination 5-3, meaning the temperature will remain within the thermal equilibrium temperature range W. However, to ensure the effective development of the pattern after exposure, the exposure illumination time T3 is relatively long, resulting in more energy output from the exposure illumination 5-3 to the pattern forming apparatus 1. At this point, the temperature of the pattern forming apparatus 1 will rise to near the upper limit of the thermal equilibrium temperature range. Therefore, to prevent the temperature from exceeding the upper limit of the thermal equilibrium temperature range during the next exposure, a cooling process can be added after the exposure step to lower the temperature and deviate it from the upper limit of the thermal equilibrium temperature range. During this cooling process, all illumination is turned off. Specifically, a cooling step S41 is added after step S3. Step S4 can be executed after the cooling step, or it can be performed during the cooling process itself, meaning cooling and moving to the next exposure field occur simultaneously. The timing switching process without a cooling step is as follows: Figure 8 As shown in the fourth scheme, the timing switching process including the cooling step is as follows: Figure 9 As shown in the fifth scheme, the first detection illumination 5-2, exposure illumination 5-3, and compensation illumination 5-4, which have a large thermal output power, are then turned off, causing the temperature of the pattern forming apparatus 1 to decrease and move away from the upper limit of the thermal equilibrium temperature range. The cooling time is T4. Of course, the second detection illumination 5-1-1 can also be turned off in this step, but since the output power fluctuates when the light source is turned off and restarted, it is preferable not to turn off the second detection illumination 5-1-1.

[0065] Based on the above embodiment, after S3, the method further includes: repeating S2 to S3, alternating between the detection step and the exposure step, and maintaining the pattern forming apparatus 1 in the thermal equilibrium temperature range during the detection step and the exposure step.

[0066] In the above embodiments, the single-block pattern forming apparatus 1 can perform multiple exposures after only one position detection. If a detection is required for the next exposure after the single exposure, it is necessary to return to step S2 after step S3 (or step S41 if it exists). The timing switching process is as follows: Figure 10 As shown (Sixth Scheme).

[0067] Based on the above embodiment, S2 includes: alternately turning on the third detection illumination 5-1-2 and the first detection illumination 5-2, wherein the single illumination cycle and single illumination duration of the third detection illumination 5-1-2 are matched with the single illumination cycle and single illumination duration of the first detection illumination 5-2; wherein, there is interference between the third detection illumination 5-1-2 and the first detection illumination 5-2, that is, when both the third detection illumination 5-1-2 and the first detection illumination 5-2 are turned on, they will affect each other's detection results.

[0068] Based on the first scheme, if multiple detection lights affect each other's detection results, meaning that only one detection light is allowed to exist at any given time, the timing control process is as follows, where the third detection light 5-1-2 is a coherent detection light. The complete process is as follows:

[0069] Step S1 includes: turning on the compensation lighting 5-4, the illumination area of ​​the compensation lighting 5-4 is C1×C2, the power density is P3, the illumination time is T1, the illumination continues until the pattern forming device 1 reaches the thermal equilibrium temperature range W, and then turning off the compensation lighting 5-4.

[0070] Step S2 includes: entering the detection lighting activation time interval, within which multiple detection lights that influence each other exist. This solution provides two coherent detection lights: the third detection light 5-1-2 and the first detection light 5-2. Within this detection lighting activation time interval, the first detection light 5-2 illuminates an area of ​​D1×D2, has a power density of P4, a single illumination cycle of T, a single illumination duration of U2, and a single field illumination time of T2. After the single field illumination time reaches T2, the first detection light 5-2 is turned off. The third detection light 5-1-2 illuminates an area of ​​N×N regions of B1×B2, has a power density of P2, a single illumination cycle of T, and a single illumination duration of U1. After the single field illumination time reaches T2, the third detection light 5-1-2 is turned off. The single illumination duration U2 of the first detection illumination 5-2 within a single illumination cycle T should be designed to match the single illumination duration U1 of the third detection illumination 5-1-2, ensuring that only one of the first detection illumination 5-2 and the third detection illumination 5-1-2 is activated at any given time to avoid mutual interference. During the single illumination time of the first detection illumination 5-2 and the third detection illumination 5-1-2, the temperature of the pattern forming apparatus 1 is maintained within the thermal equilibrium temperature range.

[0071] Step S3 includes: turning on the exposure illumination 5-3, the illumination area of ​​the exposure illumination 5-3 is E1×E2, the power density is P5, the single-field illumination time is T3, and after the single-field illumination time reaches T3, turning off the exposure illumination 5-3. During the switching process between the detection illumination and the exposure illumination 5-3, and in step S3, the temperature of the pattern forming apparatus 1 is maintained within the thermal equilibrium temperature range.

[0072] Based on the above embodiment, after S3, the method further includes: repeating S2 to S3, during which only the third detection illumination 5-1-2 is turned on in S2 and the first detection illumination 5-2 is turned off; alternating between the detection step and the exposure step, the pattern forming apparatus 1 is maintained in the thermal equilibrium temperature range during the detection step and the exposure step.

[0073] The stage 4 moves the substrate 3 to the next exposure field. Before the next exposure, the third detection illumination 5-1-2 is used to detect relevant parameters. The third detection illumination 5-1-2 illuminates N×N regions of B1×B2, with a power density of P2, a single illumination cycle of T, and a single illumination duration of U1. After the single-field illumination time reaches T2, the third detection illumination 5-1-2 is turned off; the process returns to step S3. If the pattern forming apparatus 1 is replaced, the process returns to step S1. The timing switching process is as follows: Figure 11 As shown (Seventh Scheme).

[0074] This disclosure introduces compensating illumination to achieve long-term thermal balance in the pattern forming apparatus. Thermal balance coordinates various illumination modes while ensuring minimal temperature fluctuations during light field switching, thereby controlling the range of thermal deformation in the pattern forming apparatus and ensuring uniform and stable pattern deformation during operation. Simultaneously, by rationally allocating the timing sequence and designing the illumination activation points and durations, as well as the single illumination cycle and duration, mutual interference between multiple detection lights is avoided, and the illumination required for the exposure workflow is aligned, improving exposure efficiency and thus increasing yield.

[0075] The present disclosure will be further described below through specific embodiments. The thermal control method of the above-described pattern forming apparatus will be specifically described in the following embodiments. However, the following embodiments are merely illustrative of the present disclosure, and the scope of the present disclosure is not limited thereto.

[0076] like Figure 2 As shown, in the near-field exposure system, the pattern forming apparatus 1 is adsorbed and mounted on the suction cup 2, the substrate 3 is mounted on the substrate stage 4, and the pattern forming apparatus 1 is affected by the thermal load of the first detection illumination 5-2, the second detection illumination 5-1-1, the third detection illumination 5-1-2, the exposure illumination 5-3, and the compensation illumination 5-4.

[0077] This embodiment employs a complex three-channel detection illumination. One channel, the second detection illumination 5-1-1, has low heat output power, while the other two channels, the third detection illumination 5-1-2 and the first detection illumination 5-2, have high heat output power and influence each other. The timing sequence is as follows:

[0078] Step S1: When the machine is turned on, the second detection illumination 5-1-1 and the compensation illumination 5-4 are turned on simultaneously. The second detection illumination 5-1-1 generates little heat when outputting to the pattern forming device 1. Its illumination area can be determined according to actual needs and can be kept on during machine operation. The illumination area of ​​the compensation illumination 5-4 is C1×C2, the power density is P3, and the illumination time is T1. The illumination continues until the pattern forming device 1 reaches the thermal equilibrium temperature range W, and then the compensation illumination 5-4 is turned off.

[0079] Step S2: Enter the detection lighting activation time interval. Within this interval, multiple detection lights that influence each other exist. In this embodiment, two coherent detection lights are provided: the third detection light 5-1-2 and the first detection light 5-2. During this detection lighting activation time interval, the first detection light 5-2 illuminates an area of ​​D1×D2, has a power density of P4, a single illumination cycle of T, a single illumination duration of U2, and a single field illumination time of T2. After the single field illumination time reaches T2, the detection is completed, and the first detection light 5-2 is turned off. The third detection light 5-1-2 illuminates an area of ​​N×N B1×B2 regions, has a power density of P2, a single illumination cycle of T, and a single illumination duration of U1. After the single field illumination time reaches T2, the third detection light 5-1-2 is turned off. The single illumination duration U2 of the first detection lighting 5-2 within a single illumination cycle T should be designed to match the single illumination duration U1 of the third detection lighting 5-1-2, ensuring that only one of the first detection lighting 5-2 and the third detection lighting 5-1-2 is activated at any given time to avoid mutual interference. During the single illumination time of the first detection lighting 5-2 and the third detection lighting 5-1-2, the temperature of the pattern forming apparatus 1 is maintained within the thermal equilibrium temperature range.

[0080] Step S3: Turn on exposure illumination 5-3. The illumination area of ​​exposure illumination 5-3 is E1×E2, the power density is P5, and the single-field illumination time is T3. After the single-field illumination time reaches T3, turn off exposure illumination 5-3. During the switching process between detection illumination and exposure illumination 5-3, and in step S3, the temperature of pattern forming apparatus 1 is maintained within the thermal equilibrium temperature range. Figure 12 As shown, after the first detection illumination 5-2 is turned off and the exposure illumination 5-3 is turned on, the temperature of the pattern forming apparatus 1 rises to near the upper limit of the thermal equilibrium temperature range, requiring a cooling process.

[0081] Step S4: The stage 4 moves the substrate 3 to the next exposure field. Before the next exposure, the third detection illumination 5-1-2 is used to detect relevant parameters. The illumination area of ​​the third detection illumination 5-1-2 is N×N B1×B2 regions, the power density is P2, the single illumination cycle is T, and the single illumination duration is U1. After the single field illumination time reaches T2, the third detection illumination 5-1-2 is turned off; return to step S3. The timing switching process is as follows: Figure 12 As shown. If the pattern forming device 1 is replaced, it is necessary to return to step S1.

[0082] like Figure 13 As shown, the typical lighting condition above the pattern forming apparatus 1 in this embodiment is as follows. The material of the pattern forming apparatus 1 in the following embodiment is fused silica, and the size of the illumination area is the size required for actual detection and exposure under a certain condition. The power density of each illumination output is obtained experimentally after determining the thermal equilibrium temperature range. The thermal equilibrium temperature range in this embodiment is 30.05~30.2℃. At this time, the Z-direction deformation at the center of the pattern forming apparatus 1 is 40.9nm, the Z-direction deformation at the edge of the compensation area is 21.1nm, and the surface shape PV of the compensation illumination area of ​​the pattern forming apparatus is 19.8nm.

[0083] (1) The illumination area of ​​the second detection lighting 5-1-1 is distributed at the four outer vertices of the center 25mm×30mm. Figure 13 The four points (A1×A2 area) are defined, with a single-point illumination area of ​​0.5mm×0.5mm and a single-point illumination power density of 11000mW / cm². 2 .

[0084] (2) The third detection lighting 5-1-2 has N×N B1×B2 areas, distributed in a central 20mm×20mm area, forming a 20×20 point array. The single-point lighting area is 0.1mm×0.1mm, and the single-point lighting power density is 1000mW / cm². 2 The single lighting cycle is 0.25s, and the single lighting duration is 0.06s.

[0085] (3) The lighting area of ​​the compensation lighting 5-4 is distributed within a central 40mm × 40mm area, with a lighting power density of 50mW / cm². 2 The lighting duration T1 is 1000s. At this time, the compensation lighting 5-4 directly uses the lighting components of the first detection lighting 5-2. When performing the compensation lighting function, it is called compensation lighting.

[0086] (4) The illumination area of ​​the first detection lighting 5-2 is D1×D2, distributed within a central 40mm×40mm area, with an illumination power density of 50mW / cm². 2The single lighting cycle is 0.25s, the single lighting duration is 0.03s, and the single-field testing time is 25s, meaning that the first testing lighting 5-2 is used 100 times within a single testing time. The first testing lighting 5-2 is turned off after the single-field testing is completed.

[0087] (5) The illumination area of ​​exposure lighting 5-3 is E1×E2, distributed within a central 25mm×30mm area, with an illumination power density of 60mW / cm². 2 The duration of a single lighting session is 5 seconds. For example... Figure 14 As shown, after the first detection illumination 5-2 is turned off and the exposure illumination 5-3 is turned on, the temperature approaches the upper limit of the thermal equilibrium temperature range of 30.2℃, requiring a cooling process. The cooling time is 25 seconds, after which the temperature returns to around 30.08℃ within the thermal equilibrium temperature range.

[0088] Using the thermal control scheme disclosed herein, such as Figure 14 As shown in the left-middle section, the experimental results show that the initial ambient temperature was 22℃. During the exposure process, after 1200 seconds of operation, the compensation illumination in step S1 and the first detection illumination in step S2 were completed. At this point, the pattern forming apparatus 1 had reached thermal equilibrium, with an overall temperature of 30.05℃. Figure 14 As shown in the right part, after switching to exposure illumination 5-3 in step S3, the temperature begins to rise, reaching the upper limit of the thermal equilibrium temperature range of around 30.2℃. At this time, the temperature fluctuation gradient is 0.15℃, the Z-direction deformation at the center of the pattern forming apparatus 1 is 40.9nm, and the Z-direction deformation at the edge of the compensation illumination area is 21.1nm. That is, the surface shape PV of the pattern forming apparatus is 19.8nm@25mm×30mm.

[0089] Without adopting the thermal control scheme disclosed herein, i.e., without controlling the on-time of the detection lighting and exposure lighting, such as... Figure 15 As shown, the temperature of the pattern forming apparatus 1 first rises continuously, and the temperature is greater than 40°C but has not yet reached thermal equilibrium. The temperature fluctuates significantly during the exposure process, and the temperature gradient difference between single-field detection and exposure is greater than 9°C. The surface shape PV of the pattern forming apparatus 1 is greater than 36.4nm@25mm×30mm.

[0090] This embodiment also provides a method for obtaining timing control:

[0091] The main heat input illumination is divided into a first detection illumination 5-2, an exposure illumination 5-3, and a compensation illumination 5-4. The compensation illumination 5-4 is used to heat the pattern forming apparatus 1 from room temperature to the thermal equilibrium temperature range W, making the temperature of the pattern forming apparatus 1 more uniform. This avoids excessively large differences in deformation between the center and edge of the detection area due to lack of temperature control of the pattern forming apparatus 1. The exposure illumination 5-3 is used in the pattern exposure process.

[0092] (1) First, determine the thermal equilibrium temperature range W of the pattern forming apparatus 1. The pattern forming apparatus 1 deforms under heat, and the relationship between the Z-direction deformation of the pattern forming apparatus 1 and temperature can be obtained experimentally or through simulation. At a certain temperature, the Z-direction deformation ΔZ at the edge of the compensation illumination area of ​​the pattern forming apparatus 1 is... C1×C2 The temperature range W can be taken as the thermal equilibrium temperature range if it is greater than or equal to 50% of the deformation ΔZ in the Z direction of the center of the pattern forming device.

[0093] (2) After selecting the illumination areas D1×D2, E1×E2, and C1×C2 of the first detection illumination 5-2, exposure illumination 5-3, and compensation illumination 5-4 according to the actual situation, calculate the power density and illumination duration of the first detection illumination 5-2, exposure illumination 5-3, and compensation illumination 5-4 according to the simulation model or experiment, while keeping the temperature of the pattern forming device 1 within the thermal equilibrium temperature range W.

[0094] This disclosure adopts the core idea of ​​achieving thermal balance through mutual energy compensation, which solves the problem that pattern forming apparatus cannot achieve high energy transfer in a short time. It provides an effective thermal control method for pattern forming apparatus, enabling the pattern to maintain stable deformation during operation and avoiding deformation of the exposed pattern caused by uneven heat.

[0095] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of this disclosure. It should be understood that the above descriptions are merely specific embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A thermal control method for a pattern forming apparatus, characterized in that, include: S1, turn on the compensation lighting (5-4), heat the pattern forming apparatus (1) to the thermal equilibrium temperature range, and then turn off the compensation lighting (5-4); the area of ​​the illumination region of the compensation lighting (5-4) is S. C1×C2 ; S2, turn on the first detection illumination (5-2), and turn off the first detection illumination (5-2) after the detection step is completed; the illumination area of ​​the first detection illumination (5-2) is S. D1×D2 ; S3, turn on the exposure illumination (5-3), and turn off the exposure illumination (5-3) after the exposure step is completed; the area of ​​the illumination region of the exposure illumination (5-3) is S. E1×E2 ; Among them, S C1×C2 ≥S D1×D2 ≥S E1×E2 During the switching process between S1, S2 and S3, the temperature of the pattern forming device (1) is maintained in the thermal equilibrium temperature range. Within the thermal equilibrium temperature range, the Z-direction deformation ΔZ at the edge of the compensated lighting area is... C1×C2 It is greater than or equal to 50% of the deformation ΔZ in the Z direction of the center of the pattern forming device.

2. The thermal control method for the pattern forming apparatus according to claim 1, characterized in that, Before S1, the following also applies: S0, the thermal equilibrium temperature range is determined based on the relationship between the deformation and temperature of the pattern forming device (1).

3. The thermal control method for the pattern forming apparatus according to claim 1, characterized in that, Following S3, the following also includes: S4, in the next exposure field, the exposure illumination (5-3) is turned on, and the temperature of the pattern forming apparatus (1) is maintained within the thermal equilibrium temperature range during the illumination of the exposure illumination (5-3); The time interval between the two exposure illuminations (5-3) before and after activation is T5.

4. The thermal control method for the pattern forming apparatus according to claim 3, characterized in that, The following is included before S4: S41, turn off all lighting to allow the pattern forming apparatus (1) to cool for a duration of T4; T4 may include T5 or T4 may not include T5.

5. The thermal control method for the pattern forming apparatus according to claim 1, characterized in that, Following S3, the following also includes: Repeat S2~S3, alternating between the detection step and the exposure step, and maintain the pattern forming apparatus (1) in the thermal equilibrium temperature range during the detection step and the exposure step.

6. The thermal control method for the pattern forming apparatus according to claim 1, characterized in that, S1 further includes: While the compensation lighting (5-4) is turned on, the second detection lighting (5-1-1) is also turned on. During S2 to S3, the second detection lighting (5-1-1) remains on. The heat output power of the second detection illumination (5-1-1) is less than that of the first detection illumination (5-2), and there is no interference between the second detection illumination (5-1-1) and the first detection illumination (5-2).

7. The thermal control method for the pattern forming apparatus according to claim 6, characterized in that, Following S3, the following also includes: S41, turn off all lighting to allow the pattern forming apparatus (1) to cool for a duration of T4; S4, in the next exposure field, the exposure illumination (5-3) is turned on, and the temperature of the pattern forming apparatus (1) is maintained within the thermal equilibrium temperature range during the illumination of the exposure illumination (5-3); the time interval between turning on the exposure illumination (5-3) before and after the exposure field is T5; Wherein, T4 includes T5 or T4 does not include T5.

8. The thermal control method for the pattern forming apparatus according to claim 6, characterized in that, Following S3, the following also includes: Repeat S2~S3, alternating between the detection step and the exposure step, and maintain the pattern forming apparatus (1) in the thermal equilibrium temperature range during the detection step and the exposure step.

9. The thermal control method for the pattern forming apparatus according to claim 1, characterized in that, S2 includes: The third detection light (5-1-2) and the first detection light (5-2) are alternately turned on. The single illumination cycle of the third detection light (5-1-2) matches the single illumination cycle of the first detection light (5-2), and the single illumination duration of the third detection light (5-1-2) matches the single illumination duration of the first detection light (5-2). There is interference between the third detection illumination (5-1-2) and the first detection illumination (5-2).

10. The thermal control method for the pattern forming apparatus according to claim 9, characterized in that, Following S3, the following also includes: Repeat S2~S3. During the repeated execution of S2~S3, only the third detection illumination (5-1-2) is turned on in S2, and the first detection illumination (5-2) is turned off. The detection step and the exposure step are performed alternately, and the pattern forming device (1) is maintained in the thermal equilibrium temperature range during the detection step and the exposure step.

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