A lithographic illumination system, method and lithography machine

Abstract

The present application discloses a lithographic illumination system, method and lithography machine, relating to the field of lithography technology. The lithographic illumination system includes: an asymmetric beam splitter, a monitor, an exposure device, a preset light source and a controller; the preset light is divided by the asymmetric beam splitter into monitoring light transmitted to the monitor and illumination light transmitted to the exposure device, and the controller can obtain the light field distribution of the illumination light by acquiring the light field distribution of the monitoring light obtained by the monitor, so as to achieve the monitoring effect. At the same time, when the controller determines that the light field distribution of the illumination light is abnormal, it can adaptively adjust the light source pixel parameters corresponding to the preset light output by the preset light source, so that the generated illumination light continues to achieve the effect of light homogenization. The integration of light homogenization and monitoring of the lithographic illumination system is realized through the above simple structure, greatly reducing the hardware structure complexity of the entire lithographic illumination system and reducing the interference caused by the unstable light source to the lithographic illumination system.

Description

Technical Field

[0001] The present application relates to the field of lithography technology, and in particular, to a lithography illumination system, a method, and a lithography machine. Background Art

[0002] In the prior art, as one of the core subsystems of a deep ultraviolet (DUV) lithography machine, the main function of a lithography illumination system is to achieve uniform illumination on the mask surface and various illumination modes on the pupil surface, so as to ensure that the lithography machine can obtain uniform resolution in the exposure field. Due to the extremely high requirements for illumination uniformity during the exposure process, traditional DUV lithography illumination systems need to introduce relatively complex compound eye light homogenizing devices or quartz rod waveguide light homogenizing devices for light homogenization to adjust the light field energy distribution of the light source. However, it does not have the function of monitoring the light field energy distribution and adaptively adjusting the light homogenization effect. Once the light field of the illumination light cannot meet the working requirements, it is difficult to detect in time, which is likely to cause significant losses. Even if it can be detected in time, it is necessary to replace the hardware and re-adjust the parameters of the entire lithography illumination system before it can be used again. This not only makes the structure of the entire lithography illumination system complex, but also makes it difficult to solve the interference caused by unstable operation of the light source. Summary of the Invention

[0003] The main purpose of the present application is to provide a lithography illumination system, a method, and a lithography machine, aiming to solve the technical problem of how to integrate light homogenization and monitoring in the lithography illumination system, thereby reducing the hardware structure complexity of the entire lithography illumination system and reducing the interference caused by unstable light sources to the operation of the entire system.

[0004] To achieve the above object, an embodiment of the present application provides a resonance regulation device. The lithography illumination system includes: an asymmetric beam splitter, a monitor, an exposure device, a preset light source, and a controller;

[0005] The controller is electrically connected to the monitor and the preset light source respectively;

[0006] The asymmetric beam splitter is arranged on the light output path of the preset light source, and is used for refracting and reflecting the preset light emitted by the preset light source, generating monitoring light and illumination light on different optical paths respectively, transmitting the monitoring light to the monitor, and simultaneously transmitting the illumination light to the exposure device;

[0007] The exposure device is used for performing exposure processing on a wafer to be processed based on the obtained illumination light;

[0008] The monitor is used for monitoring the light field distribution data of the monitoring light and transmitting the corresponding light field information to the controller;

[0009] The controller is configured to send a light homogenization control signal to the preset light source based on the light field information;

[0010] The preset light source is configured to adjust the light source pixel parameters of the preset light based on the light homogenization control signal.

[0011] In one embodiment, one surface of the asymmetric beam splitter faces the preset light source, configured to receive the preset light and reflect the illumination light, and the other surface of the asymmetric beam splitter is configured to refract the monitoring light.

[0012] In one embodiment, one surface of the asymmetric beam splitter faces the preset light source, configured to receive the preset light and reflect the monitoring light, and the other surface of the asymmetric beam splitter is configured to refract the illumination light.

[0013] In one embodiment, a dielectric layer and a functional layer are provided between the two surfaces of the asymmetric beam splitter;

[0014] The dielectric layer is made of an isotropic homogeneous material or an anisotropic material;

[0015] The functional layer is made of a metal material or an optical dielectric material.

[0016] In one embodiment, one surface of the asymmetric beam splitter is a smooth surface covered with an optical coating.

[0017] In one embodiment, the asymmetric beam splitter is further configured to perform decoherence processing on the preset light when receiving the preset light to obtain the illumination light, and transmit the illumination light to the exposure device.

[0018] In one embodiment, the exposure device includes: a mask stage, a projection objective system, a wafer stage, and a calibration stage;

[0019] The mask stage is configured to carry a mask;

[0020] The projection objective system is configured to change the projection pattern of the received illumination light through the mask, and focus and project the illumination light onto the wafer to be processed through an objective lens group;

[0021] Wherein, the wafer stage is configured to carry the wafer to be processed; the calibration stage is configured to calibrate the relative position between the mask and the wafer to be processed.

[0022] In one embodiment, the setting manner between the mask and the wafer stage is any one of contact type, proximity type, and projection type.

[0023] In addition, to achieve the above object, the present application also proposes a lithographic illumination method, which is applied to the lithographic illumination system described above. The steps of the lithographic illumination method include:

[0024] Controlling a preset light source to emit preset light to an asymmetric beam splitter, obtaining light field information corresponding to the monitoring light generated by the asymmetric beam splitter through a monitor, and at the same time causing an exposure device to perform exposure with the illumination light generated by the asymmetric beam splitter;

[0025] Based on the light field information, controlling the preset light source to adjust the light source pixel parameters of the preset light so as to adjust the illumination light.

[0026] In addition, to achieve the above object, the present application also provides a lithography machine, which adopts the lithographic illumination system described above.

[0027] The embodiments of the present application provide a lithographic illumination system, method and lithography machine. The lithographic illumination system includes: an asymmetric beam splitter, a monitor, an exposure device, a preset light source and a controller; the controller is electrically connected to the monitor and the preset light source respectively; the asymmetric beam splitter is arranged on the light output path of the preset light source and is used for refracting and reflecting the preset light emitted by the preset light source, generating monitoring light and illumination light on different optical paths respectively, transmitting the monitoring light to the monitor, and at the same time transmitting the illumination light to the exposure device; the exposure device is used for performing exposure processing on the wafer to be processed based on the obtained illumination light; the monitor is used for monitoring the light field distribution data of the monitoring light and transmitting the corresponding light field information to the controller; the controller is used for sending a light homogenization control signal to the preset light source based on the light field information; the preset light source is used for adjusting the light source pixel parameters of the preset light based on the light homogenization control signal. By using the asymmetric beam splitter to divide the preset light into the monitoring light transmitted to the monitor and the illumination light transmitted to the exposure device, the controller can obtain the light field distribution of the illumination light by obtaining the light field distribution of the monitoring light obtained by the monitor, so as to achieve the monitoring effect. At the same time, when the controller determines that the light field distribution of the illumination light is abnormal, it can adaptively adjust the light source pixel parameters corresponding to the preset light output by the preset light source, so that the generated illumination light can continue to achieve the light homogenization effect. The integration of light homogenization and monitoring of the lithographic illumination system is realized through the above simple structure, greatly reducing the hardware structure complexity of the entire lithographic illumination system and reducing the interference caused by the unstable light source to the lithographic illumination system. Description of the Drawings

[0028] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application and used together with the specification to explain the principles of the present application.

[0029] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0030] Figure 1 It is a schematic structural diagram provided for the first embodiment of the lithography illumination system of the present application;

[0031] Figure 2 It is a schematic diagram of modulating the illumination brightness and polarization state corresponding to the preset light output by the preset light source;

[0032] Figure 3 It is a structural diagram of an asymmetric beam splitter;

[0033] Figure 4 It is an optical path diagram when the asymmetric beam splitter is working;

[0034] Figure 5 It is a schematic flow chart provided for the first embodiment of the lithography illumination method of the present application;

[0035] Figure 6 It is another schematic flow chart provided for the first embodiment of the lithography illumination method of the present application;

[0036] Figure 7 It is a schematic diagram of the illumination light field distribution.

[0037] The realization of the purpose, functional features, and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. Specific Embodiments

[0038] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0039] To better understand the technical solutions of the present application, the following will be described in detail in combination with the accompanying drawings of the specification and specific embodiments.

[0040] The present application proposes a lithography illumination system for the first embodiment. Please refer to Figure 1 , the lithography illumination system includes: an asymmetric beam splitter 10, a monitor 20, an exposure device 30, a preset light source 40, and a controller 50;

[0041] The controller 50 is electrically connected to the monitor 20 and the preset light source 40 respectively;

[0042] The asymmetric beam splitter 10 is disposed on the light output path of the preset light source 40, and is configured to refract and reflect the preset light emitted by the preset light source 40, generate monitoring light and illumination light on different optical paths respectively, transmit the monitoring light to the monitor 20, and simultaneously transmit the illumination light to the exposure device 30;

[0043] The exposure device 30 is configured to perform an exposure process on the wafer to be processed based on the acquired illumination light;

[0044] The monitor 20 is configured to monitor the light field distribution data of the monitoring light and transmit the corresponding light field information to the controller 50;

[0045] The controller 50 is configured to send a light homogenization control signal to the preset light source based on the light field information;

[0046] The preset light source 40 is configured to adjust the light source pixel parameters of the preset light based on the light homogenization control signal.

[0047] It should be noted that, in this embodiment, the controller 50 actually refers to an electronic device having functions such as data processing function and control function. Specifically, it can be a server, or an electronic terminal device such as a smart phone, a personal computer (PC), a tablet computer, or a portable computer. The controller 50 can send control signals or control instructions such as light homogenization control signals that can control the working state of the preset light source 40 to control the working state of the preset light source 40.

[0048] It should be understood that the preset light source 40 can specifically be a pixel-level controllable light source array, which includes at least one light emitting sub-unit. The light emitting sub-unit can be any one of a light emitting diode (LED), an organic light emitting diode (OLED), a quantum dot light emitting diode (QLED), and a micro light emitting diode (Micro LED). The exposure wavelength of each light emitting sub-unit is a wavelength with a relatively high photosensitive response, and the light emitted by each light emitting sub-unit includes but is not limited to a central wavelength of deep ultraviolet wavelength; the modulation of the brightness (including on / off state) and polarization state of each pixel of the light source is as Figure 2As shown, each pixel can unify the polarization state change by adding a large-aperture electrically controlled polarizer, or add a pixel-level liquid crystal spatial light modulator to customize the polarization state change of a single pixel, similar to the light intensity waveforms corresponding to the light source pixel 1, the light source pixel 2, and the light source pixel 3 in the figure. In this embodiment, the light source pixel parameters can be understood as the light parameters at the pixel level of the preset light emitted by the preset light source 40.

[0049] It should be noted that, in this embodiment, the asymmetric beam splitter 10 can adopt a bi-anisotropic design, so that its reflection characteristics and transmission characteristics can be adjusted independently. Bi-anisotropy refers to a special physical property, in which there is an electromagnetic coupling phenomenon between the electric field and the magnetic field, that is, the electric field can cause magnetization, and the magnetic field can cause electrode polarization. The bi-anisotropy can be used to adjust the optical transmission path. It can be arranged on the light output path of the preset light source 40 to emit the preset light, and the corresponding monitoring light and the corresponding illumination light are generated through its transmission characteristics and reflection characteristics. Since the input light is all the same-source preset light and the optical modulation characteristics of the asymmetric beam splitter 10 itself are fixed, the light field distribution characteristics of the monitoring light and the illumination light are similar, and can be estimated according to the modulation function in the design of the asymmetric beam splitter 10 itself.

[0050] It is easy to understand that, in the initial state, the preset light source 40 can first send the initial preset light to the asymmetric beam splitter 10. After receiving the preset light, the asymmetric beam splitter 10 sends the monitoring light to the monitor 20 after refraction or reflection, and at the same time sends the illumination light to the exposure device 30 after reflection or refraction. The monitor 20 can monitor the received monitoring light, so as to obtain the light field distribution data of the monitoring light, and transmit the light field distribution data to the controller 50 in the form of light field information. When receiving the light field information, the controller 50 can obtain the light field distribution data of the illumination light through the light field distribution data of the monitoring light. Subsequently, the light field distribution data of the currently obtained illumination light is analyzed to determine whether the illumination uniformity corresponding to the currently sent preset light meets the requirements, so as to determine whether it is necessary to adjust the light source pixel parameters of the preset light source 40. If it is determined that the illumination uniformity does not meet the requirements, a corresponding light uniformity control signal can be sent to control the operating state of the light source pixels of the preset light source 40, including the intensity, phase, and amplitude distribution of the preset light. In this way, the light parameters of the illumination light received by the exposure device 30 are changed, so that the exposure device 30 can perform exposure processing on the object to be processed with the optimal light parameters.

[0051] Among them, the controller 50 reads the light field distribution data of the received monitoring light sent by the monitor 20, determines the corresponding light field information of the illumination light reaching the exposure device 30 through an intelligent core algorithm, then determines the combination of each point light source in the preset light source 40 by using the learning and training results, finds the array combination that realizes the ideal light homogenization effect, and issues an instruction to the light source, thus realizing a lithography illumination system that integrates monitoring and light homogenization.

[0052] It should be noted that, in this embodiment, the monitor 20 includes a device for receiving optical signals, including but not limited to cameras, photodiodes, and avalanche photodiode sensors set based on complementary metal oxide semiconductors and charge-coupled device sensors, etc.

[0053] Furthermore, in this embodiment, please refer to Figure 1 the left figure in, as a specific case, one surface of the asymmetric beam splitter 10 is arranged facing the preset light source 40, used to receive the preset light and reflect the illumination light, and the other surface of the asymmetric beam splitter 10 is used to refract the monitoring light.

[0054] It should be noted that, in this embodiment, the asymmetric beam splitter 10 can receive the incident light generated by the preset light source 40, that is, the preset light, through one of its surfaces. The preset light can reach the two surfaces of the asymmetric beam splitter 10 in sequence along its incident direction, and both surfaces are used to reflect and refract the preset light to emit light beams from the two surfaces respectively. Among them, in combination with Figure 3 , one surface of the asymmetric beam splitter 10 can be a smooth ordinary optical surface (smooth surface), and the other surface can be a special optical surface (diffuse reflection surface). The optical paths of the light refracted by the ordinary optical surface and the special optical surface are the same, and it will be modulated into monitoring light and refracted to the monitor 20. The light reflected by the special optical surface will form incoherent illumination light due to diffuse reflection modulation and / or diffusion light modulation of the optical path and be reflected to the exposure device 30.

[0055] It should be noted that, in this embodiment, an optical coating for adjusting the overall light transmittance and reflectivity can be plated on one surface (smooth surface) of the asymmetric beam splitter 10, so as to adjust the ratio of the reflected light and refracted light formed by the light reaching the ordinary optical surface, and further control the intensity ratio of the illumination light and the monitoring light to obtain the required intensity ratio.

[0056] Furthermore, referring to Figure 1 the right figure in, as another case, one surface of the asymmetric beam splitter 10 is arranged facing the preset light source 40, used to receive the preset light and reflect the monitoring light, and the other surface of the asymmetric beam splitter 10 is used to refract the illumination light.

[0057] It should be noted that in this embodiment, in combination with Figure 3 , since there are certain differences in the internal structures (such as thickness) of the functional layer 12, the optical paths of the light refracted by the ordinary optical surface and the special optical surface will be modulated, forming decoherent illumination light and refracting it to the exposure device 30. The optical paths of the light reflected by the ordinary optical surface and the special optical surface are the same, and are modulated into monitoring light and reflected to the monitor 20.

[0058] Furthermore, in this embodiment, a dielectric layer 11 and a functional layer 12 are provided between the two surfaces of the asymmetric beam splitter 10;

[0059] The dielectric layer 11 is made of an isotropic homogeneous material or an anisotropic material;

[0060] The functional layer 12 is made of a metal material or an optical dielectric material.

[0061] It is easy to understand that in this embodiment, in combination with Figure 3 , the dielectric layer 11 is close to one surface, and the functional layer 12 is close to the other surface. The material of the dielectric layer 11 is an isotropic homogeneous material. An isotropic homogeneous material refers to a material whose physical, chemical and other properties do not vary due to different directions, and the performance values measured along different directions are exactly the same, such as glass materials and fused silica materials with homogeneity; it can also be an anisotropic material. An anisotropic material refers to a material whose all or part of the physical, chemical and other properties show certain differences with different directions, and the performance values measured in different directions are different, such as birefringent materials. The material of the functional layer 12 can be a metal material such as gold or titanium, etc., or other optical dielectric materials with optical properties. In a specific implementation, the transmission characteristics and reflection characteristics of the asymmetric beam splitter 10 can be designed by adjusting the relative position relationship and their respective thicknesses between the dielectric layer 11 and the functional layer 12.

[0062] It is worth noting that in this embodiment, in combination with Figure 4 , Figure 4It is an illustration of the refraction and reflection of light passing through two surfaces of an asymmetric beam splitter, and it does not limit whether it is an ordinary optical surface or a special optical surface. In the specific light transmission path of the asymmetric beam splitter 10, the incident light I can respectively form a reflected light R12 and a refracted light T12 after passing through one surface (the first and second numbers in the subscript respectively represent the media on the incident side and the transmission side of the interface. For example, R12 represents the reflected light incident from medium A to medium B). The overall thickness of the asymmetric beam splitter 10 is d. The refracted light can be transmitted through the asymmetric beam splitter 10 to another surface and respectively form a reflected light R23 and a refracted light T23. The reflected light can be transmitted back to one surface and respectively form a reflected light R21 and a refracted light T21. Further, the reflected light R21 can further be transmitted to another surface and respectively form a reflected light and a refracted light, which will not be elaborated here. Among them, the aforementioned reflected light R12 and refracted light T21 are the light beams exiting from one surface to medium A, and the refracted light T23 is the light beam exiting from another surface to medium C.

[0063] Further, in this embodiment, the exposure device 30 includes: a mask stage, a projection objective system, a wafer stage, and a calibration stage;

[0064] The mask stage is used to carry a mask;

[0065] The projection objective system is used to change the projection pattern of the received illumination light through the mask and focus and project the illumination light onto the wafer to be processed through an objective lens group;

[0066] Among them, the wafer stage is used to carry the wafer to be processed; the calibration stage is used to calibrate the relative position between the mask and the wafer to be processed.

[0067] It should be noted that in this embodiment, the exposure device 30 includes a mask stage, a projection objective system, a wafer stage, a calibration stage, etc. (not shown in the figure). Among them, the mask stage is used to carry a mask, and the wafer stage is used to carry a wafer to realize the functions of alignment, leveling, focusing, stepping, and scanning exposure; the projection objective system is used to focus the pattern on the mask onto the surface of the wafer to be processed; the calibration stage is used to complete the alignment and correction of the mask and the wafer to be processed.

[0068] Further, in this embodiment, the setting manner between the mask and the wafer stage is any one of contact type, proximity type, and projection type.

[0069] It should be noted that in this embodiment, the exposure device 30 can be configured for any one of proximity exposure, contact exposure, and projection exposure. Among them, when using contact and proximity exposure methods, the exposure device 30 may not include a projection objective system.

[0070] An embodiment of the present application provides a lithography illumination system, which includes: an asymmetric beam splitter, a monitor, an exposure device, a preset light source, and a controller; the controller is electrically connected to the monitor and the preset light source respectively; the asymmetric beam splitter is disposed on the light output path of the preset light source, and is configured to refract and reflect the preset light emitted by the preset light source, generate monitoring light and illumination light on different optical paths respectively, transmit the monitoring light to the monitor, and at the same time transmit the illumination light to the exposure device; the exposure device is configured to perform exposure processing on a wafer to be processed based on the obtained illumination light; the monitor is configured to monitor the light field distribution data of the monitoring light and transmit the corresponding light field information to the controller; the controller is configured to send a light homogenization control signal to the preset light source based on the light field information; the preset light source is configured to adjust the light source pixel parameters of the preset light based on the light homogenization control signal. The preset light is divided into monitoring light transmitted to the monitor and illumination light transmitted to the exposure device by the asymmetric beam splitter. The controller can obtain the light field distribution of the illumination light by obtaining the light field distribution of the monitoring light acquired by the monitor, so as to achieve the monitoring effect. At the same time, when the controller determines that the light field distribution of the illumination light is abnormal, it can adaptively adjust the light source pixel parameters corresponding to the preset light output by the preset light source, so that the generated illumination light can continue to achieve the light homogenization effect. The integration of light homogenization and monitoring of the lithography illumination system is realized through the above simple structure, which greatly reduces the hardware structure complexity of the entire lithography illumination system and reduces the interference caused by the unstable light source to the lithography illumination system.

[0071] In addition, to achieve the above object, the present application also proposes a lithography illumination method, which is applied to the lithography illumination system as described above, as Figure 5 and Figure 6 shown, the steps of the lithography illumination method include steps S10 - S20:

[0072] Step S10, controlling the preset light source to emit preset light to the asymmetric beam splitter, obtaining the light field information corresponding to the monitoring light generated by the asymmetric beam splitter through the monitor, and at the same time enabling the exposure device to perform exposure through the illumination light generated by the asymmetric beam splitter;

[0073] Step S20, based on the light field information, controlling the preset light source to adjust the light source pixel parameters of the preset light so as to adjust the illumination light.

[0074] It should be noted that in this embodiment, the execution subject may be the controller as described above. In the initial state, the controller controls the preset light source to emit preset light to the asymmetric beam splitter.

[0075] It is easy to understand that in this embodiment, after the preset light passes through the asymmetric beam splitter, a pair of monitoring light and illumination light can be generated respectively through the transmission characteristic and the reflection characteristic. By changing the angle between the asymmetric beam splitter and the original light transmission path of the preset light, the generated monitoring light can be transmitted to the monitor, and at the same time, the generated incoherent illumination light can be transmitted to the exposure device, so that the exposure device exposes the wafer to be processed through the received illumination light. The light field information corresponding to the light field distribution data of the monitoring light received by the monitor can be obtained, so as to confirm the current light field distribution of the monitoring light. Since both the monitoring light and the illumination light are obtained by splitting the same-source preset light, the light field distribution of the illumination light can also be determined by combining the light field distribution of the monitoring light with the modulation function designed by the asymmetric beam splitter. Subsequently, based on the comparison between the light field distribution of the illumination light and the ideal light field distribution, it can be confirmed whether it meets the requirements of the current exposure device. If not, the light source pixel parameters of the output preset light can be adjusted by controlling the preset light source, so as to adjust the light parameters (light field distribution) of the illumination light to the best, so that the exposure device works in the best state.

[0076] In addition, it should also be noted that in this embodiment, the execution subject can use neural network deep learning to seek the corresponding relationship between the monitoring end and the exposure end. The core algorithm process of the neural network is as follows. First, data preparation is carried out, including data cleaning, handling missing values and outliers, data standardization, standardizing or normalizing the data to ensure that each feature is on the same scale; secondly, data splitting is carried out, and the data set is split into a training set, a validation set and a test set. A common ratio is 70% training set, 15% validation set, and 15% test set; then, a neural network model is built, and a suitable neural network architecture is selected, such as recurrent neural networks (RNN), convolutional neural networks (CNN), fully connected neural networks (FCNN), etc., and a deep learning framework is used to build the neural network model, such as TensorFlow or PyTorch; secondly, the model is trained, and the model is trained with the training data and verified on the validation data; then, the model is evaluated, and the model performance is evaluated using the test data set; then, hyperparameter tuning and model optimization are carried out. According to the performance results of the model, hyperparameter tuning and model optimization can be carried out, such as adjusting the number of network layers, the number of neurons in each layer, the learning rate, etc.; repeat the process from training the model to tuning and optimizing the parameters until the model meets the application requirements. Finally, the model is used for prediction to obtain the corresponding relationship between the light field distributions of the exposure end and the monitoring end, generate the corresponding light source pixel parameter combination for realizing the target uniform illumination light field pattern distribution, and realize the function of integrating monitoring and uniform illumination and the function of pupil shaping.

[0077] It should be noted that, on the basis of considering light homogenization, the controller can individually regulate the illumination combination of each pixel light source inside the preset light source through an intelligent algorithm to achieve a specific illumination light field pattern distribution, and realize the pupil shaping function of the traditional illumination system. Common illumination methods are as Figure 7 shown, including typical parametric illumination morphological distributions such as monopole, dipole, quadrupole, annular, ASML dipole, and ASML quadrupole illumination.

[0078] Furthermore, in this embodiment, the step of controlling the preset light source to adjust the light source pixel parameters of the preset light based on the light field information to adjust the illumination light includes:

[0079] Step S21, based on the light field information, obtain the light field distribution data of the current monitoring light;

[0080] Step S22, based on the light field distribution data of the monitoring light, obtain the light field distribution data of the current illumination light;

[0081] Step S23, when the light field distribution data of the illumination light does not conform to the preset light field data, output a corresponding light homogenization control signal to the preset light source, and adjust the light source pixel parameters of the preset light source to adjust the illumination light.

[0082] It should be noted that the preset light field data refers to the light field distribution data of the illumination light demand that the exposure device needs to receive in an ideal state. In this embodiment, first, the light field distribution data of the corresponding monitoring light can be obtained through the light field information obtained by the monitoring light. Based on the algorithm of the neural network model described above and the modulation function in the design of the asymmetric beam splitter, the relationship between the monitoring light and the illumination light can be deduced, and the light field distribution data of the illumination light can be obtained by combining the light field distribution data of the monitoring light. If the currently obtained light field distribution data of the illumination light does not conform to the theoretically preset light field data, a corresponding light homogenization control signal can be sent to the preset light source to adjust the light source pixel parameters corresponding to the preset light source, that is, change the illumination combination of each pixel light source in the preset light source, so as to adjust the light field uniformity (light field distribution) of the preset light, and further realize the adaptive adjustment of the light field distribution of the illumination light. Through the above method, the integration of light homogenization and monitoring of the lithography illumination system can be realized, ensuring that the exposure device can always receive the illumination light with the best light parameters to expose the wafer to be processed. While reducing the hardware structure complexity of the entire lithography illumination system, the stability of the entire lithography illumination system can also be ensured.

[0083] In addition, to achieve the above object, the present application further provides a lithography machine, and the lithography machine adopts the lithography illumination system as described above. Since the lithography machine adopts all the embodiments of the lithography illumination system as described above, it should also have the beneficial effects brought by each embodiment of the above lithography illumination system, which will not be elaborated here one by one.

[0084] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be included in the patent scope of the present application by the same token.

Claims

1. A lithography illumination system, characterized in that: The photolithography illumination system comprises: an asymmetric beam splitter, a monitor, an exposure device, a preset light source and a controller; The controller is electrically connected to the monitor and the preset light source respectively; The asymmetric beam splitter is arranged on the light output path of the preset light source, and is used to refract and reflect the preset light emitted by the preset light source, generate monitoring light and illumination light on different light paths, and transmit the monitoring light to the monitor, and transmit the illumination light to the exposure device at the same time; The exposure device is used to perform exposure processing on the wafer to be processed based on the acquired illumination light; The monitor is used to monitor the light field distribution data of the monitoring light and transmit the corresponding light field information to the controller; The controller is used to send a corresponding light uniformity control signal to the preset light source based on the light field information, the designed neural network model and the modulation function corresponding to the asymmetric beam splitter; The preset light source is used to adjust the light source pixel parameters of the preset light based on the uniform light control signal, the light source pixel parameters include the light intensity, phase and amplitude distribution of the preset light, and the preset light is deep ultraviolet wavelength light; The asymmetric beam splitter is further used to, when receiving the preset light, perform decoherence processing on the preset light to obtain the illumination light, and transmit the illumination light to the exposure device.

2. The lithography illumination system according to claim 1, characterized in that: One surface of the asymmetric beam splitter is disposed toward the preset light source and is used to receive the preset light and reflect the illumination light. The other surface of the asymmetric beam splitter is used to refract the monitoring light.

3. The lithography illumination system according to claim 1, wherein: One surface of the asymmetric beam splitter is arranged toward the preset light source, and is used to receive the preset light and reflect the monitoring light. The other surface of the asymmetric beam splitter is used to refract the illumination light.

4. The lithography illumination system according to claim 1, wherein: A dielectric layer and a functional layer are provided between the two surfaces of the asymmetric beam splitter; The dielectric layer is made of isotropic homogeneous material or anisotropic material; The functional layer is made of metal material or optical medium material.

5. The lithography illumination system according to claim 4, characterized in that: One surface of the asymmetric beam splitter is a smooth surface covered with an optical coating.

6. The lithography illumination system according to claim 1, wherein: The exposure device comprises: a mask workpiece stage, a projection lens system, a wafer workpiece stage and a calibration stage; The mask workpiece stage is used to carry the mask plate; The projection objective lens system is used to change the projection pattern of the received illumination light through the mask, and focus the illumination light to the wafer to be processed through the objective lens group; Wherein, the wafer worktable is used to carry the wafer to be processed; and the calibration table is used to calibrate the relative position between the mask and the wafer to be processed.

7. The lithography illumination system according to claim 6, characterized in that: The mask plate and the wafer worktable are arranged in any one of a contact type, a proximity type and a projection type.

8. A photolithography illumination method, characterized in that: Applied to the lithography illumination system according to any one of claims 1 to 7, the steps of the lithography illumination method include: Controlling a preset light source to emit preset light to the asymmetric beam splitter, and obtaining light field information corresponding to the monitoring light generated by the asymmetric beam splitter through a monitor, while causing an exposure device to perform exposure through the illumination light generated by the asymmetric beam splitter; Based on the light field information, the designed neural network model and the modulation function of the asymmetric beam splitter, the preset light source is controlled to adjust the light source pixel parameters of the preset light to adjust the illumination light, and the light source pixel parameters include the light intensity, phase and amplitude distribution of the preset light.

9. A photolithography machine, characterized in that: The lithography machine adopts the lithography illumination system as described in any one of claims 1-7.

Images