CN116755297B

CN116755297B - Exposure resolution optimization method and device, electronic equipment and storage medium

Info

Publication number: CN116755297B
Application number: CN202311037238.7A
Authority: CN
Inventors: 曹子峥; 周延; 皮雅稚; 余少华
Original assignee: Peng Cheng Laboratory
Current assignee: Peng Cheng Laboratory
Priority date: 2023-08-17
Filing date: 2023-08-17
Publication date: 2023-10-27
Anticipated expiration: 2043-08-17
Also published as: CN116755297A

Abstract

The application discloses an exposure resolution optimization method, an exposure resolution optimization device, electronic equipment and a storage medium, and relates to the field of lithography.A lithography system adjustable exposure parameter and an exposure result of the adjustable exposure parameter are input into a preset optimization model to obtain a target parameter, wherein the adjustable exposure parameter at least comprises a light source phase; adjusting the lithography system based on the target parameters to form a lithography system with new exposure parameters; and (3) performing exposure by the lithography system based on the new exposure parameters to obtain new exposure results, taking the target parameters as new adjustable exposure parameters, and returning to perform the step of inputting the adjustable exposure parameters of the lithography system and the exposure results of the adjustable exposure parameters into a preset optimization model to obtain the target parameters based on the new adjustable exposure parameters and the new exposure results. According to the embodiment of the application, the phase of the light source is added as one of the adjustable exposure parameters, and the light source participates in the optimization process, so that the optimization direction is enriched, the regulation and control fineness is improved, and the enhancement effect of the photoetching resolution is improved.

Description

Exposure resolution optimization method and device, electronic equipment and storage medium

Technical Field

The present application relates to the field of photolithography, and in particular, to a method and apparatus for optimizing exposure resolution, an electronic device, and a storage medium.

Background

Resolution enhancement techniques (Resolution enhancement technique, RET) widely used in modern lithography are mainly to improve the lithography resolution by reducing the k1 factor associated with the lithography process to achieve the largest common process window (Common process window, CPW). The existing RET technique generally simulates and calculates the optimal light source condition and/or mask structure on the light source side and/or mask side under the condition of known constraint conditions, wherein, in terms of light source side optimization, the optimization is generally aimed at improving the illumination uniformity of the light source and reducing the cost of a light source system, while in terms of mask side optimization, one of the aims is to optimize the mask structure so that the light intensity of a dark area is reduced in a light field formed by interference when light passes through a mask, and the light intensity of a bright area is enhanced, thereby improving the contrast and resolution. However, the optimization direction of the optimization mode is limited, and the optimization fineness is insufficient, so that the enhancement effect of the exposure resolution in the photoetching process is limited.

Disclosure of Invention

The application mainly aims to provide an exposure resolution optimization method, an exposure resolution optimization device, electronic equipment and a storage medium, and aims to solve the technical problems that the optimization direction of the traditional resolution enhancement technology is limited, the optimization fineness is insufficient, and the exposure resolution enhancement effect is limited in the photoetching process.

In order to achieve the above object, the present application provides an exposure resolution optimization method, comprising:

inputting an adjustable exposure parameter of a lithography system and an exposure result of the adjustable exposure parameter into a preset optimization model to obtain a target parameter, wherein the adjustable exposure parameter at least comprises a light source phase;

adjusting the lithography system based on the target parameters to form new exposure parameters;

and performing exposure by the lithography system based on the new exposure parameters to obtain new exposure results, taking the target parameters as new adjustable exposure parameters, and returning to execute the step of inputting the adjustable exposure parameters of the lithography system and the exposure results of the adjustable exposure parameters into a preset optimization model based on the new adjustable exposure parameters and the new exposure results to obtain the target parameters until the exposure results reach a preset exposure resolution standard.

Optionally, the light source in the lithography system is configured with a phase type liquid crystal array panel, the target parameter includes a target phase, and the step of adjusting the lithography system based on the target parameter to form a lithography system with a new exposure parameter includes:

and adjusting the additional phases of different positions of the phase type liquid crystal array panel so that the phase of light emitted by the light source after passing through the phase type liquid crystal array panel is the same as the target phase, thereby forming the lithography system with the new exposure parameters.

Optionally, the target phase includes local target phase timing data of different positions, and the step of adjusting the additional phases of different positions of the phased liquid crystal array panel includes:

generating additional phase timing data for any position in the phase type liquid crystal array panel based on an original phase of a light source and local target phase timing data of the position;

and adjusting an additional phase of the position based on the additional phase timing data.

Optionally, the preset optimization model is SMO, the adjustable exposure parameters further include light source intensity and a mask structure, the target parameters further include target light intensity and a target structure, and the step of inputting the adjustable exposure parameters of the lithography system and the exposure results of the adjustable exposure parameters to the preset optimization model to obtain the target parameters includes:

Inputting the light source phase, the light source intensity, the mask structure, and the exposure result to the SMO;

and performing joint optimization of a light source and a mask through the SMO to generate the target phase, the target light intensity and the target structure.

Optionally, the preset optimizing model is SO, the adjustable exposure parameter further includes a light source intensity and a preset mask structure, the target parameter further includes a target light intensity, and the step of inputting the adjustable exposure parameter of the lithography system and an exposure result of the adjustable exposure parameter to the preset optimizing model to obtain the target parameter includes:

inputting the light source phase, the light source intensity, the preset mask structure and the exposure result to the SO;

and performing light source optimization through the SO to generate the target phase and the target light intensity.

Optionally, the lithography system with new exposure parameters includes a target phase type liquid crystal array panel and a target mask, and the step of exposing the lithography system based on the new exposure parameters to obtain a new exposure result includes:

a light source in the photoetching system is projected onto an exposure object through a target mask through a target light field obtained by penetrating through the target phase type liquid crystal array panel, so that an exposure product is obtained;

And taking the resolution measurement result of the exposure product as the exposure result.

The step of projecting a light source in the lithography system to an exposure object through a target mask in a target light field obtained by passing the light source through the target phase type liquid crystal array panel to obtain an exposure product comprises the following steps:

acquiring a photoetching step length from a photoetching step length sequence corresponding to the target phase based on a preset sequence, and projecting a target light field associated with the photoetching step length onto the exposure object through the target mask to obtain a semi-finished product;

and taking the semi-finished product as a new exposure object, executing the step of acquiring a photoetching step length from a photoetching step length sequence corresponding to the target phase based on the new exposure object, projecting a target light field associated with the photoetching step length onto the exposure object through the target mask to obtain the semi-finished product until each photoetching step length in the photoetching step length sequence is traversed to obtain the exposure product.

In addition, in order to achieve the above object, the present application also provides an exposure resolution optimizing apparatus comprising:

the initial optimization module is used for inputting the adjustable exposure parameters of the lithography system and the exposure results of the adjustable exposure parameters into a preset optimization model to obtain target parameters, wherein the adjustable exposure parameters at least comprise a light source phase;

The parameter adjusting module is used for adjusting the lithography system based on the target parameters to form a lithography system with new exposure parameters;

the intelligent initial optimization module is used for carrying out exposure on the lithography system based on the new exposure parameters to obtain new exposure results, taking the target parameters as new adjustable exposure parameters, and returning to execute the step of inputting the adjustable exposure parameters of the lithography system and the exposure results of the adjustable exposure parameters into a preset optimization model to obtain the target parameters based on the new adjustable exposure parameters and the new exposure results until the exposure results reach a preset exposure resolution standard.

In addition, to achieve the above object, the present application also provides an electronic device including: the system comprises a memory, a processor and an exposure resolution optimization program stored in the memory and capable of running on the processor, wherein the exposure resolution optimization program realizes the steps of the exposure resolution optimization method when being executed by the processor.

In addition, in order to achieve the above object, the present application also provides a storage medium having stored thereon an exposure resolution optimization program which, when executed by a processor, implements the steps of the exposure resolution optimization method as described above.

The embodiment of the application provides an exposure resolution optimization method, an exposure resolution optimization device, electronic equipment and a storage medium. In the embodiment of the application, an adjustable exposure parameter of a lithography system and an exposure result of the adjustable exposure parameter are input into a preset optimization model to obtain a target parameter, wherein the adjustable exposure parameter at least comprises a light source phase; adjusting the lithography system based on the target parameters to form new exposure parameters; and performing exposure by the lithography system based on the new exposure parameters to obtain new exposure results, taking the target parameters as new adjustable exposure parameters, and returning to execute the step of inputting the adjustable exposure parameters of the lithography system and the exposure results of the adjustable exposure parameters into a preset optimization model based on the new adjustable exposure parameters and the new exposure results to obtain the target parameters until the exposure results reach a preset exposure resolution standard. Compared with the prior art, the embodiment of the application adds the phase of the light source as one of the adjustable exposure parameters, participates in the optimization process, enriches the optimization direction, improves the fine degree of regulation and control, and realizes a larger common process window, thereby improving the enhancement effect of the exposure resolution.

Drawings

FIG. 1 is a schematic diagram of an electronic device in a hardware operating environment according to an embodiment of the present application;

FIG. 2 is a flow chart of a first embodiment of the exposure resolution optimization method of the present application;

FIG. 3 is a flowchart of a second embodiment of the exposure resolution optimization method according to the present application;

FIG. 4 is a schematic diagram of a lithography system in the exposure resolution optimization method of the present application;

FIG. 5 is a schematic diagram of the output waveforms of the time-division and space-division amplitude modulation array light source in the exposure resolution optimization method of the present application;

FIG. 6 is a schematic diagram of an output waveform of a light source after adding a space-phase modulation LCD panel in the exposure resolution optimization method of the present application;

FIG. 7 is a schematic diagram of the waveform of the light source output after the time-division and space-division phase modulation of the liquid crystal panel in the exposure resolution optimization method of the present application;

FIG. 8 is a schematic view of a cyclic optimization flow including SMO in the exposure resolution optimization method of the present application;

FIG. 9 is a schematic diagram of SO in the exposure resolution optimization method of the present application;

FIG. 10 is a schematic diagram of a proximity exposure lithography system in direct phase optimization mode in the exposure resolution optimization method of the present application;

FIG. 11 is a schematic diagram of a projection exposure lithography system in direct phase optimization mode in the exposure resolution optimization method of the present application;

FIG. 12 is a schematic diagram of a proximity exposure lithography system in phase and intensity co-optimization mode in the exposure resolution optimization method of the present application;

FIG. 13 is a schematic diagram of a projection exposure lithography system in phase and intensity co-optimization mode in the exposure resolution optimization method of the present application;

fig. 14 is a schematic view of an exposure resolution optimizing apparatus in the exposure resolution optimizing method of the present application.

The achievement of the objects, functional features and advantages of the present application will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

Referring to fig. 1, fig. 1 is a schematic diagram of an electronic device structure of a hardware running environment according to an embodiment of the present application.

The electronic equipment of the embodiment of the application can be a server, and also can be electronic terminal equipment such as a smart phone, a PC, a tablet personal computer, a portable computer and the like.

As shown in fig. 1, the electronic device may include: a processor 1001, such as a CPU, a network interface 1004, a user interface 1003, a memory 1005, a communication bus 1002. Wherein the communication bus 1002 is used to enable connected communication between these components. The user interface 1003 may include a Display, an input unit such as a Keyboard (Keyboard), and the optional user interface 1003 may further include a standard wired interface, a wireless interface. The network interface 1004 may optionally include a standard wired interface, a wireless interface (e.g., WI-FI interface). The memory 1005 may be a high-speed RAM memory or a stable memory (non-volatile memory), such as a disk memory. The memory 1005 may also optionally be a storage device separate from the processor 1001 described above.

Optionally, the electronic device may further include a camera, an RF (Radio Frequency) circuit, a sensor, an audio circuit, a WiFi module, and the like. The terminal may also be configured with other sensors such as gyroscopes, barometers, hygrometers, thermometers, infrared sensors, etc., which are not described in detail herein. Those skilled in the art will appreciate that the electronic device structure shown in fig. 1 is not limiting of the electronic device and may include more or fewer components than shown, or may combine certain components, or may be arranged in different components.

Those skilled in the art will appreciate that the electronic device structure shown in fig. 1 is not limiting of the electronic device and may include more or fewer components than shown, or may combine certain components, or may be arranged in different components.

Further, as shown in fig. 1, an operating system, a network communication module, a user interface module, and an exposure resolution optimization program may be included in the memory 1005 as one type of computer storage medium.

In the electronic device shown in fig. 1, the network interface 1004 is mainly used for connecting to a background server and performing data communication with the background server; the user interface 1003 is mainly used for connecting a client (user side) and performing data communication with the client; and the processor 1001 may be configured to call an exposure resolution optimization program stored in the memory 1005 and perform the following operations:

In a possible implementation, the processor 1001 may call the exposure resolution optimization program stored in the memory 1005, and further perform the following operations:

the light source in the lithography system is configured with a phase type liquid crystal array panel, the target parameter comprises a target phase, and the step of adjusting the lithography system based on the target parameter to form a lithography system with a new exposure parameter comprises the following steps:

the target phase includes local target phase time sequence data of different positions, and the step of adjusting the additional phases of different positions of the phase type liquid crystal array panel includes:

the step of inputting the adjustable exposure parameters of the lithography system and the exposure results of the adjustable exposure parameters into the preset optimization model to obtain target parameters comprises the following steps:

the lithography system with the new exposure parameters comprises a target phase type liquid crystal array panel and a target mask, and the steps of exposing the lithography system based on the new exposure parameters to obtain new exposure results comprise the following steps:

For clarity of explanation of the present solution, a brief explanation of the conventional solution will now be provided.

Existing RETs can be generally classified into light source optimization (Source optimization, SO), mask optimization (Mask optimization, MO) and joint optimization of both, according to the lithography system part in which they are located. The optimization of the light source side is to obtain the optimal illumination condition under the constraint condition through simulation calculation according to the design pattern of the existing mask plate (also called mask for short) so as to realize the maximum CPW; the mask side optimization is to obtain the optimal mask pattern and structure design under the constraint condition through simulation calculation under the known illumination condition. Existing mainstream RET includes illumination source optimization such as Off-axis illumination (Off-axis illumination, OAI), mask optimization such as photo proximity correction (Optical proximity correction, OPC), phase-shifting masks (PSM) and Sub-resolution assist features (Sub-resolution assistant feature, SRAF), and source-reticle joint optimization (Source mask optimization, SMO).

In the existing SMO scheme, besides the design of geometric space shape of the light transmission/reflection area (such as OPC and SRAF) for the optimization of the mask, phase modulation can be used to improve the optimization efficiency (such as PSM and its derivative scheme). The PSM generates an optimized aerial image on the surface of the photoresist by modulating the intensity and the phase of the light field at the same time, thereby obtaining higher photoetching resolution. Specifically, the specially designed mask structure on the PSM makes the light waves transmitted through adjacent light transmitting areas generate phase difference, and the two interfere in a specific area on the image plane, so that the light intensity of a dark area in light field distribution is reduced, the light intensity of a bright area is increased, and the contrast ratio and resolution ratio are improved. Another way is to use the phase gradient of adjacent patterns to generate the light field direction reversal and zero field region to improve the steepness of the pattern edge and the pattern contrast. Steepening the light field intensity distribution between the bright-dark regions improves the exposure energy tolerance (Exposure latitude, EL) and thus CPW increases. The development of PSM technology is increasingly emerging in different categories. In terms of functional classification, most typical alternating phase shift masks (Alternating phase shifting mask, altPSM) produce 180 degree phase differences in light waves transmitted through adjacent light transmissive regions, while attenuated phase shift masks (Attenuated phase shifting mask, attPSM) incorporate transmittance changes to further improve modulation accuracy, and edge enhanced phase shift masks (Rim PSM), chrome-less/All-transparent phase shift masks (Chrome-less/All-transparent PSM), strictly optimized phase shift masks (Rigorously optimized phase shifting mask, RO-PSM), synthetic holographic phase shift masks (Synthetic holographic phase shifting mask, holo-PSM), and composite phase shift masks combining different types of PSM, among others. Of the single types of PSMs, alternating, attenuated, and fully transparent PSMs provide the most significant resolution improvement. In terms of structural classification, the masks applying the phase shift principle are mainly four types of binary phase shift masks (Binary phase mask, BPM), binary composite masks (Binary complex mask, BCM), multilayer phase shift masks (Multilevel phase mask, MPM) and multilayer composite masks (Multilevel complex mask, MCM). Among them, MPM mainly used for fine phase modulation is least used in practical applications. Generally, binary structured masks are used to produce 180 degrees of phase difference, and multi-layer structured masks are used to produce finer (e.g., 60 degrees) phase difference. The composite mask can achieve both intensity and phase modulation relative to a pure phase shift mask. It can be seen that the phase is used as a parametric dimension, and the modulation of the phase can further improve the optimization of pattern transfer in exposure lithography, and can be organically combined with intensity optimization to be applied to mask optimization technology.

For optimization of the light source side, the technology applied to the proximity lithography mainly focuses on improving the illumination uniformity and reducing the cost of the light source system, while the technology applied to the projection lithography adopts a free-form light source (FFS) based on a digital micromirror (Digital micromirror device, DMD) for pixel illumination. Existing FFS increase CPW by mainly controlling the spatial intensity distribution of the light field, increasing EL or decreasing mask error enhancement factors (Mask error enhancement factor, MEEF), helping to improve exposure resolution.

In general, current light source side optimization schemes focus on the spatial intensity distribution of the light field, while for phase adjustment is mainly achieved by structural adjustment of the mask. In order to further enrich the direction during optimization and improve the degree of freedom of optimization, the phase adjustment of the light source is added, namely the phase adjustment is carried out on the light source side, on one hand, the phase adjustment can be simultaneously realized on the basis of the light source and the mask, the optimization fineness is further improved, and the resolution enhancement effect is improved. On the other hand, the phase adjustment of the light source side can be used for replacing the phase adjustment of the mask side, so that the complexity of the mask structure is reduced, and the manufacturing cost is reduced.

Referring to fig. 2, a first embodiment of the exposure resolution optimization method of the present application includes:

step S10, inputting an adjustable exposure parameter of a lithography system and an exposure result of the adjustable exposure parameter into a preset optimization model to obtain a target parameter, wherein the adjustable exposure parameter at least comprises a light source phase;

it should be noted that a lithography system will typically comprise four parts, for example as shown with reference to fig. 4, including illumination by a light source, light transmission 1, image output, light transmission 2 and image transfer.

The light source illumination section may be divided into a light intensity modulation system including a light source, which may be a planar light source or a pixel-level adjustable array light source, and a phase modulation system. The planar light source is a combination of devices capable of outputting planar light waves, such as a combination of a mercury lamp light source and a uniform illumination element. The pixel-level adjustable array light source is formed by an arrayed light emitting unit, and the light emitting unit comprises, but is not limited to, a Laser Diode (LD), a light emitting diode (Light emitting diodes, LED), an organic light emitting diode (Organic light emitting diodes, OLED), a quantum dot light emitting diode (Quantum dot light emitting diodes, QLED), a Micro light emitting diode (Micro LED) and the like. Each light emitting unit of the arrayed light source can individually control its switching state and brightness, i.e. the pixel level is controllable, so each light emitting unit can be called a light source pixel. The exposure wavelength of the light source in the present embodiment is a wavelength with a higher photosensitive response of the target optical colloid, including but not limited to ultraviolet (center wavelength 400 nm) and ultraviolet to deep ultraviolet band (200 to 380 nm), etc. The light intensity modulation system may be used for adjusting the light intensity of the light source, while the phase modulation system is used for adjusting the phase of the light source, for example, the adjustment of the phase of the light source may be achieved by a spatial light modulator (phase type liquid crystal array panel).

The optical transmission 1 and the optical transmission 2 can be set by technicians according to different requirements or devices, and can be free space or an optical transmission system. Wherein, when the light transmission part is an optical transmission system, the light emitted from the light source part can be subjected to modulation and conditioning during the process of irradiating the pattern output part, wherein the modulation and conditioning comprises one or a proper combination of several of focusing, beam expanding, phase delaying and the like. Accordingly, the optical transmission system can be set as one or a proper combination of several of refractive lens (group), reflecting mirror (group), phase delay device, etc. according to different requirements.

The image output section, typically a reticle/mask containing the pattern to be printed, and its onboard control system. The pattern (i.e., structure) on the reticle is the original pattern to be printed, or the pattern is optimized, including but not limited to OPC, PSM, SRAF, etc.

The pattern transfer portion is a sample of a wafer silicon wafer having a surface coated with spin-on photoresist, typically to which the desired printed pattern is ultimately transferred, including but not limited to a photosensitive material (including but not limited to photoresist) and associated load bearing and control portions. The image transfer may be achieved by an exposure system, which may be a proximity exposure lithography system or a projection exposure lithography system. In the case of a proximity exposure lithography system, the portions of light transmission 1 and light transmission 2 may be free spaces, and for light transmission 2, the distance between the reticle bottom surface of the pattern output portion and the substrate surface of the pattern transfer portion may be in the interval of several micrometers to several hundred micrometers. If the projection exposure lithography system is characterized in that the light transmission 2 part is an optical transmission system, a system for optical projection exists between the mask plate of the pattern output part and the substrate of the pattern transfer part.

And according to different light source illumination systems, the method can be divided into a direct optimization mode and a phase and intensity collaborative optimization mode.

In the direct phase optimization mode, the illumination light source part is a planar light source, and the light waves output from the light source surface are directly subjected to spatially distributed phase modulation through the phase type liquid crystal array panel. Referring to fig. 10, a schematic diagram of a direct phase optimization mode proximity exposure lithography system according to the present application includes a planar light source, a liquid crystal panel (i.e., a phase type liquid crystal array panel), a mask plate, and an exposure wafer. Referring to FIG. 11, a schematic diagram of a projection exposure lithography system in direct phase optimization mode according to the present application includes a planar light source, a liquid crystal panel (i.e., a phase type liquid crystal array panel), a mask, a projection system, and an exposure wafer.

In the phase and intensity collaborative optimization mode, the illumination light source part is an arrayed light source with adjustable and controllable intensity space distribution, and light intensity distribution modulation light waves output from a light source surface pass through a phase type liquid crystal array panel and are subjected to phase modulation of time-space distribution. Referring to fig. 12, a schematic diagram of a proximity exposure lithography system in a phase and intensity co-optimization mode includes an array light source, a liquid crystal panel, a mask plate, and an exposure wafer. FIG. 13 is a schematic diagram of a projection exposure lithography system in phase and intensity co-optimization mode, including an array light source, a liquid crystal panel, a mask plate, a projection system, and an exposure wafer.

Based on the above lithography system, lithography of an exposure object by a light source can be realized. When optimizing the exposure resolution, the exposure resolution is improved by adjusting the adjustable exposure parameters of the lithography system, so as to achieve better lithography effect.

For example, after one lithography is completed, the adjustable exposure parameters used in the lithography and the exposure result obtained by the lithography are input into a preset optimization model to obtain target parameters. The adjustable exposure parameters at least comprise a light source phase, and can also comprise light source intensity, a mask structure and the like. The exposure result is a measurement of the exposure product and may be, for example, a resolution achievable by photolithography. The input preset optimization model may be SMO and may also be SO. SMO and SO are all existing optimization modes, SO that specific optimization processes can refer to the existing schemes, and detailed description is omitted here. And optimizing the optimization model based on the input adjustable exposure parameters and the exposure result to obtain an optimization result, namely a target parameter. It should be noted that, if the adjustable exposure parameter includes only the light source phase and is optimized, the target phase of the light source will generally exist in the target parameter, and if the adjustable exposure parameter includes not only the light source phase but also the light source intensity or the mask structure, the target phase may exist or not in the target parameter, and the target phase may be determined specifically by the actual optimization result of the preset optimization model.

Step S20, adjusting the lithography system based on the target parameters to form a lithography system with new exposure parameters;

illustratively, the lithographic system is adjusted according to a target parameter, for example, if the target parameter includes a target phase, the light source phase adjustment may be performed by a phase modulation system in the illumination of the light source, and similarly, if the target parameter includes a light intensity, the adjustment may be performed by a light intensity modulation system. If the target parameter includes a mask structure, the mask of the lithography system is replaced, so that the structure of the replaced mask and the mask structure of the target parameter are sufficient. After the adjustment is completed, the lithography system with new exposure parameters can be obtained.

And step S30, performing exposure by the lithography system based on the new exposure parameters to obtain new exposure results, taking the target parameters as new adjustable exposure parameters, and returning to the step of inputting the adjustable exposure parameters of the lithography system and the exposure results of the adjustable exposure parameters into a preset optimization model based on the new adjustable exposure parameters and the new exposure results to obtain the target parameters until the exposure results reach a preset exposure resolution standard.

Illustratively, the lithography system based on the new exposure parameters described above performs exposure, in which the light source typically emits a light field through the phase and/or intensity modulation system, which is projected through the mask onto an exposure object, such as a wafer, to expose the pattern on the mask onto the wafer. And taking the measured result of the exposed wafer as a new exposure result, taking the target parameter as a new adjustable exposure parameter, and returning and executing the step of inputting the adjustable exposure parameter of the lithography system and the exposure result of the adjustable exposure parameter into a preset optimization model based on the new adjustable exposure parameter and the new exposure result to obtain the target parameter. And (5) completing optimization until the exposure result reaches a preset exposure resolution standard. At this time, the lithography system can achieve a better lithography effect, i.e. the resolution of the pattern obtained by lithography meets the rated requirements.

In this embodiment, an adjustable exposure parameter of a lithography system and an exposure result of the adjustable exposure parameter are input into a preset optimization model to obtain a target parameter, wherein the adjustable exposure parameter at least includes a light source phase; adjusting the lithography system based on the target parameters to form new exposure parameters; and performing exposure by the lithography system based on the new exposure parameters to obtain new exposure results, taking the target parameters as new adjustable exposure parameters, and returning to execute the step of inputting the adjustable exposure parameters of the lithography system and the exposure results of the adjustable exposure parameters into a preset optimization model based on the new adjustable exposure parameters and the new exposure results to obtain the target parameters until the exposure results reach a preset exposure resolution standard. Compared with the prior art, the embodiment of the application adds the phase of the light source as one of the adjustable exposure parameters, participates in the optimization process, enriches the optimization direction, improves the fine degree of regulation and control, and realizes a larger common process window, thereby improving the enhancement effect of the exposure resolution.

In a possible embodiment, the light source in the lithography system is configured with a phase type liquid crystal array panel, the target parameter includes a target phase, and the step of adjusting the lithography system based on the target parameter to form a lithography system with a new exposure parameter includes:

Step S210, adjusting the additional phases of different positions of the phase type liquid crystal array panel so that the phase of the light emitted by the light source after passing through the phase type liquid crystal array panel is the same as the target phase, thereby forming the lithography system with the new exposure parameters.

In this embodiment, the photolithography system is configured with a phase type liquid crystal array panel, that is, the light emitted by the light source is phase modulated by the phase type liquid crystal array panel, and the target parameters include a target phase.

For example, the additional phases of different positions of the phased array panel are adjusted, in this embodiment, an arrayed light source with 3×4 pixels is taken as an example, and referring to fig. 5, a schematic diagram of output waveforms of the time-division and space-division amplitude modulation array light source in the present application is shown, where the amplitude is also light intensity, and the light source 1 includes a light source point a, a light source point B, and a light source point C, where the light source 1 exists, and an output waveform diagram of each light source point. Fig. 5 is a waveform diagram without phase modulation, and further referring to fig. 6, a schematic diagram of an output waveform of a light source after adding a space-phase modulation liquid crystal panel according to the present application is shown. The light source 1 and the phase type liquid crystal array panel 2 are included in the figure, and the light source 1 and the phase type liquid crystal array panel 2 are normally and correspondingly stacked together in order. Taking light source point a, light source point B and light source point C as examples in the figure, the additional phases provided at the positions corresponding to light source point a, light source point B and light source point C on the phase type liquid crystal array panel 2 are +0, -pi/2 and +pi, respectively. It can be seen that, in fig. 6, after the light of the pixel point B and the pixel point C modulate the phase through the phase type liquid crystal array panel, the phase of the waveform chart correspondingly output is different from the phase of the waveform chart output at the pixel point B and the pixel point C in fig. 5. The specific adjustment content on the phase type liquid crystal array panel is mainly based on the target phase. The phase of the light emitted by the light source after passing through the phase type liquid crystal array panel is the same as the target phase.

In a possible embodiment, the target phase includes local target phase timing data of different positions, and the step of adjusting the additional phases of different positions of the phased liquid crystal array panel includes:

step S211, for any position in the phase type liquid crystal array panel, generating additional phase time sequence data based on the original phase of the light source and local target phase time sequence data of the position;

step S212, adjusting an additional phase of the position based on the additional phase timing data.

The target phase includes local target phase time series data of different positions, for example, local target phase time series data of the light source point a based on the above example, and the local target phase time series data is time-varying phase data of a certain light source point. I.e. for one light source point its phase may be different at different moments in time.

Illustratively, at any position in the phased liquid crystal array panel, additional phase timing data is generated by the original phase of the light source and local target phase timing data of the position, for example, subtracting the local target phase timing data from the original phase to obtain the additional phase timing data. And then adjusting the additional phase of the position based on the additional phase time sequence data. Referring to fig. 7, a schematic diagram of the waveform of the output of the light source after the time-division and space-division phase modulation liquid crystal panel according to the present application is shown. The light source 1 and the phase type liquid crystal array panel 2 are included in the figure, and it can be seen from the figure that the phases emitted by the light source point a and the light source point B are different at different times and are added by the phase type liquid crystal array panel.

It will be appreciated that in this implementation, the local target phase timing data for different positions of the target phase in the target parameter, i.e. the result of the optimization, includes two variable dimensions for the phase, space-division and time-division, and the same, i.e. the source phase at the adjustable exposure parameter includes a space-division source phase (i.e. the phase of different source points) and a time-division source phase (i.e. the phase of one source point at different moments). Therefore, the application further increases the adjustable dimension of the light source phase, enriches the optimized direction, improves the fine degree of regulation and control and improves the enhancement effect of resolution.

In a possible implementation manner, the preset optimization model is SMO, the adjustable exposure parameters further include light source intensity and a mask structure, the target parameters further include target light intensity and a target structure, and the step of inputting the adjustable exposure parameters of the lithography system and the exposure results of the adjustable exposure parameters to the preset optimization model to obtain the target parameters includes:

step S111, inputting the light source phase, the light source intensity, the mask structure, and the exposure result to the SMO;

and step S112, performing joint optimization of a light source and a mask through the SMO, and generating the target phase, the target light intensity and the target structure.

It should be noted that the preset optimization model may be SMO, and the adjustable exposure parameters further include light source intensity and mask structure, and the target parameters further include target light intensity and target structure.

Exemplary, referring to fig. 8, a schematic flow chart of loop optimization including SMO in the present application is shown. And inputting an exposure result and adjustable exposure parameters (comprising a light source phase, a light source intensity and a mask structure) into the SMO, and performing joint optimization of the light source and the mask to obtain an optimization result (namely target parameters comprising a target phase, a target light intensity and a target structure). And performing exposure based on the optimized result (namely, performing exposure after adjusting each exposure parameter in the lithography system to be consistent with the target parameter), obtaining an exposure result after exposure, and judging whether the exposure result is converged (namely, judging whether the exposure result reaches a preset resolution standard or not). If yes, the exposure parameters of the lithography system can meet the preset resolution requirement, and the light-phase optimized light source and the image/structure optimized mask are output. If not, the exposure result and the adjustable exposure parameters are input into the SMO for optimization.

For illustration based on the system of fig. 11, the system includes a mercury lamp (i-line, center wavelength 365 nm) planar light source with a uniform illumination element, a phase modulation system based on a transmissive pixel-level tunable phase type liquid crystal array panel, a reticle carrying a pattern to be written, a 4:1 projection system including an optical lens group, and a target wafer. Based on the system settings, exposure process 1 is performed: the emergent light intensity of the planar light source is kept unchanged, the emergent light passes through a space-division-adjustable phase modulation system, a light field carrying space-division phase modulation and space intensity distribution is formed through a mask, and a projection system projects the light field to the surface of a wafer according to the ratio of 4:1, so that exposure is completed. The projection system ensures that the illumination field carrying the mask pattern information is the optimal imaging plane when projected onto the wafer surface. Based on parameters adopted in the exposure process and measurement results (exposure parameters and exposure results), SMO is input, and the optimization results are output as follows: the intensity of the planar light source, the time-division phase control data of each pixel point in the phase modulation system, the space phase distribution formed on the phase type liquid crystal panel in unit modulation time, and the optimized pattern/structure of the mask. And (3) performing exposure (namely photoetching) based on the optimization result, and inputting the exposure result and the corresponding exposure parameters into the SOM model for optimization if the exposure result is not converged, and continuously cycling until the exposure result is converged.

Based on the SMO optimization results described above, an exposure process is performed in which step-wise exposure can be performed according to the desired time-and space-phase modulation schemes.

In a possible implementation manner, the preset optimization model is SO, the adjustable exposure parameters further include light source intensity and a preset mask structure, the target parameters further include target light intensity, and the step of inputting the adjustable exposure parameters of the lithography system and the exposure results of the adjustable exposure parameters to the preset optimization model to obtain the target parameters includes:

step S121, inputting the light source phase, the light source intensity, the preset mask structure and the exposure result to the SO;

and step S122, performing light source optimization through the SO to generate the target phase and the target light intensity.

Exemplary, reference is made to fig. 9 for a schematic diagram of an SO in the present application. The light source parameters (light source phase and light source intensity), the exposure result and the given mask parameters (preset mask structure) are input into SO, the light source optimization is carried out through SO, the light source optimization can comprise phase time division optimization, phase space division optimization, light intensity space division optimization and light intensity time division optimization, the result after the SO optimization is to optimize the light source parameters, the light source parameters comprise a target phase and the target light intensity, the target phase can be a phase on time division and/or space division, and the target light intensity can be a phase on time division and/or space division.

The system based on fig. 13 is exemplified, and the system comprises a pixel-level adjustable array light source composed of arrayed UV-LED (central wavelength 365 nm) light-emitting units, a phase modulation system based on a transmissive pixel-level adjustable phase type liquid crystal array panel, a mask plate carrying a pattern to be written, a 4:1 projection system comprising an optical lens group, and a target wafer. Based on the system settings, an exposure process is performed: the light intensity of the emergent light of the array light source is kept unchanged, the emergent light passes through a space-division-adjustable phase modulation system, a light field carrying space-division phase modulation and space intensity distribution is formed through a mask, and a projection system projects the light field to the surface of a wafer according to the ratio of 4:1, so that exposure is completed. The projection system ensures that the illumination field carrying the mask pattern information is the optimal imaging plane when projected onto the wafer surface. Based on the optimization algorithm of the flow of inputting the photometric parameters, the given mask pattern and the exposure result adopted in the exposure process to SO, the optimization result 1 is output as follows: the time division intensity parameter of each light emitting unit, the space division intensity distribution formed on the pixel level adjustable array light source in unit modulation time, the time division phase control parameter of each pixel point in the phase modulation system and the space division phase distribution formed on the phase type liquid crystal panel in unit modulation time. Based on the SO model optimization result, exposure is executed again, and in the exposure process, corresponding step-by-step exposure can be executed according to the required intensity and phase modulation schemes of time division and space division. Subsequent cyclic process lithography may refer to cyclic processes for SMO and will not be described in detail herein.

It should be noted that the optimization process for the light source is also performed in SMO, and SO is different from SMO, in that the result of SO has no mask parameter. It can be understood that in this example, the optimizable dimension of the light source side is increased, and the optimization is performed by using SO, SO that modification of the mask can be avoided, complexity in optimization is reduced, and optimization cost is reduced.

Referring to fig. 3, a second embodiment of the present application is proposed based on the first embodiment of the present application, and the same parts as those of the above embodiment in this embodiment can be referred to the above, and will not be repeated here. The lithography system with the new exposure parameters comprises a target phase type liquid crystal array panel and a target mask, and the steps of exposing the lithography system based on the new exposure parameters to obtain new exposure results comprise the following steps:

step A10, a target light field obtained by a light source in a photoetching system through the target phase type liquid crystal array panel is projected onto an exposure object through a target mask to obtain an exposure product;

and step A20, taking the resolution measurement result of the exposure product as the exposure result.

The phase type liquid crystal array panel in the lithography system of the new exposure parameters formed was the target phase type liquid crystal array panel, and the mask in the lithography system of the same new exposure parameters was the target mask.

The light emitted by the light source is transmitted through the target phase type liquid crystal array panel to obtain a target light field subjected to phase modulation on space division and/or time division, and then the target light field is projected onto an exposure object (such as a wafer) through a target mask, so that an exposure product such as an exposed wafer can be obtained. The above process is an exposure process, and is also an exposure process.

In a possible implementation manner, the step of projecting the target light field obtained by the light source in the lithography system through the target phase type liquid crystal array panel onto the exposure object through the target mask to obtain the exposure product includes:

step B110, acquiring a photoetching step from a photoetching step sequence corresponding to the target phase based on a preset sequence, and projecting a target light field associated with the photoetching step onto the exposure object through the target mask to obtain a semi-finished product;

and step B120, taking the semi-finished product as a new exposure object, executing the step B based on the new exposure object to acquire a photoetching step from a photoetching step sequence corresponding to the target phase based on a preset sequence, projecting a target light field associated with the photoetching step onto the exposure object through the target mask to obtain the semi-finished product until each photoetching step in the photoetching step sequence is traversed to obtain the exposure product.

Illustratively, in the present embodiment, to further improve the fineness of photolithography, step exposure may be performed. For example, referring to fig. 7, a light source point a and a light source point B will be described as examples. In the waveform diagrams of the light source point a and the light source point B, the period occupied by the high-order waveform appearing at the same time can be regarded as a lithography step length, and the additional phase corresponding to the high-order waveform is the additional phase in the corresponding period in the local phase time sequence data in the target phase, so that each lithography step length in the lithography step length sequence actually corresponds to each additional phase duration period in the local phase time sequence data. The preset sequence is a time sequence, a lithography step length (such as a time period) is obtained from the lithography step length sequence based on the time sequence, and then a target light field (i.e. a modulated light field after passing through an additional phase in the local phase time sequence data, which is the same as the lithography step length in the same time period) associated with the lithography step length is projected onto the exposure object through a target mask to obtain a semi-finished product. It can be understood that the semi-finished product is not exposed at this time, the step of exposing the semi-finished product based on the next lithography step length is continued, that is, the semi-finished product is used as a new exposure object, the lithography step length is acquired from the lithography step length sequence corresponding to the target phase based on the preset sequence based on the new exposure object, the target light field associated with the lithography step length is projected onto the exposure object through the target mask, and the semi-finished product is obtained until each lithography step length in the lithography step length sequence is traversed, and the exposure product can be obtained. It will be appreciated that in this implementation, step lithography (i.e., step exposure) may be performed. Compared with the photoetching of a finished product obtained by one-step photoetching, the photoetching precision can be improved by steps, or the adjustability in photoetching is improved, and the optimization direction in optimization is enriched.

Referring to fig. 14, in addition, an embodiment of the present application further provides an exposure resolution optimization apparatus 100, where the exposure resolution optimization apparatus 100 includes:

the initial optimization module 10 is configured to input an adjustable exposure parameter of the lithography system and an exposure result of the adjustable exposure parameter to a preset optimization model to obtain a target parameter, where the adjustable exposure parameter at least includes a light source phase;

a parameter adjustment module 20, configured to adjust the lithography system to form a lithography system with new exposure parameters based on the target parameters;

the intelligent initial optimization module 30 is configured to perform exposure on the lithography system based on the new exposure parameter to obtain a new exposure result, take the target parameter as a new adjustable exposure parameter, and return to perform the step of inputting the adjustable exposure parameter of the lithography system and the exposure result of the adjustable exposure parameter to a preset optimization model based on the new adjustable exposure parameter and the new exposure result to obtain the target parameter until the exposure result reaches a preset exposure resolution standard.

Optionally, the light source in the lithography system is configured with a phase type liquid crystal array panel, the target parameter includes a target phase, and the parameter adjusting module 20 is further configured to:

Optionally, the target phase includes local target phase timing data of different positions, and the parameter adjusting module 20 is further configured to:

Optionally, the preset optimization model is SMO, the adjustable exposure parameters further include light source intensity and mask structure, the target parameters further include target light intensity and target structure, and the initial optimization module 10 is further configured to:

Optionally, the preset optimization model is SO, the adjustable exposure parameters further include light source intensity and a preset mask structure, the target parameters further include target light intensity, and the initial optimization module 10 is further configured to:

Optionally, the lithography system of the new exposure parameter includes a target phase type liquid crystal array panel and a target mask, and the intelligent initial optimization module is further configured to 30:

Optionally, the intelligent initial optimization module is further configured to 30:

The exposure resolution optimization device provided by the application adopts the exposure resolution optimization method in the embodiment, and aims to solve the technical problems that the optimization direction of the traditional resolution enhancement technology is limited, the optimization fineness is insufficient, and the photoetching resolution enhancement effect is limited. Compared with the prior art, the beneficial effects of the exposure resolution optimization device provided by the embodiment of the application are the same as those of the exposure resolution optimization method provided by the embodiment, and other technical features in the exposure resolution optimization device are the same as those disclosed by the method of the embodiment, so that the description is omitted herein.

The specific implementation manner of the electronic device of the present application is substantially the same as the above embodiments of the exposure resolution optimization method, and will not be described herein.

The specific implementation manner of the storage medium of the present application is basically the same as that of each embodiment of the above-mentioned exposure resolution optimization method, and will not be repeated here.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or system. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or system that comprises the element.

The foregoing embodiment numbers of the present application are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.

From the above description of the embodiments, it will be clear to those skilled in the art that the above-described embodiment method may be implemented by means of software plus a necessary general hardware platform, but of course may also be implemented by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art in the form of a software product stored in a storage medium (e.g. ROM/RAM, magnetic disk, optical disk) as described above, comprising instructions for causing a terminal device (which may be a mobile phone, a computer, a server, or a network device, etc.) to perform the method according to the embodiments of the present application.

The foregoing description is only of the preferred embodiments of the present application, and is not intended to limit the scope of the application, but rather is intended to cover any equivalents of the structures or equivalent processes disclosed herein or in the alternative, which may be employed directly or indirectly in other related arts.

Claims

1. An exposure resolution optimization method, characterized in that the exposure resolution optimization method comprises:

inputting an adjustable exposure parameter of a lithography system and an exposure result of the adjustable exposure parameter into a preset optimization model to obtain a target parameter, wherein the adjustable exposure parameter at least comprises a light source phase, and the preset optimization model is an SMO light source mask joint optimization model or an SO light source optimization model;

performing exposure by the lithography system based on the new exposure parameters to obtain new exposure results, taking the target parameters as new adjustable exposure parameters, and returning to execute the step of inputting the adjustable exposure parameters of the lithography system and the exposure results of the adjustable exposure parameters to a preset optimization model based on the new adjustable exposure parameters and the new exposure results to obtain target parameters until the exposure results reach a preset exposure resolution standard;

Wherein, the light source is configured with a phase type liquid crystal array panel in the lithography system, the target parameter comprises a target phase, and the step of adjusting the lithography system based on the target parameter to form a lithography system with a new exposure parameter comprises the following steps:

adjusting additional phases at different positions of the phase type liquid crystal array panel so that the phase of light emitted by a light source after passing through the phase type liquid crystal array panel is the same as the target phase, thereby forming a lithography system with new exposure parameters;

wherein the target phase includes local target phase timing data of different positions, and the step of adjusting the additional phases of different positions of the phase type liquid crystal array panel includes:

2. The method of claim 1, wherein the predetermined optimization model is a SMO light source mask joint optimization model, the adjustable exposure parameters further include a light source intensity and a mask structure, the target parameters further include a target light intensity and a target structure, and the step of inputting the adjustable exposure parameters of the lithography system and the exposure results of the adjustable exposure parameters to the predetermined optimization model to obtain the target parameters includes:

3. The method of optimizing exposure resolution according to claim 2, wherein the predetermined optimization model is an SO light source optimization model, the adjustable exposure parameters further include a light source intensity and a predetermined mask structure, the target parameters further include a target light intensity, and the step of inputting the adjustable exposure parameters of the lithography system and the exposure results of the adjustable exposure parameters to the predetermined optimization model to obtain the target parameters includes:

4. A method of optimizing exposure resolution according to any one of claims 1 to 3, wherein the lithography system for new exposure parameters includes a target phase type liquid crystal array panel and a target mask, and the step of exposing the lithography system based on new exposure parameters to obtain new exposure results includes:

5. The method of optimizing exposure resolution as claimed in claim 4, wherein the step of projecting a light source in the lithography system through a target light field obtained by the target phase type liquid crystal array panel onto an exposure object through a target mask to obtain an exposure product comprises:

6. An exposure resolution optimizing apparatus, characterized in that the exposure resolution optimizing apparatus comprises:

the initial optimization module is used for inputting the adjustable exposure parameters of the lithography system and the exposure results of the adjustable exposure parameters into a preset optimization model to obtain target parameters, wherein the adjustable exposure parameters at least comprise light source phases, and the preset optimization model is an SMO light source mask joint optimization model or an SO light source optimization model;

the intelligent initial optimization module is used for carrying out exposure on the lithography system based on the new exposure parameters to obtain new exposure results, taking the target parameters as new adjustable exposure parameters, and returning to execute the step of inputting the adjustable exposure parameters of the lithography system and the exposure results of the adjustable exposure parameters into a preset optimization model to obtain the target parameters based on the new adjustable exposure parameters and the new exposure results until the exposure results reach a preset exposure resolution standard;

7. An electronic device comprising a memory, a processor, and an exposure resolution optimization program stored on the memory and executable on the processor, wherein: the exposure resolution optimization program, when executed by the processor, implements the steps of the exposure resolution optimization method according to any one of claims 1 to 5.

8. A storage medium having stored thereon an exposure resolution optimization program which, when executed by a processor, implements the steps of the exposure resolution optimization method according to any one of claims 1 to 5.