Illumination imaging method and device, exposure equipment and medium

Abstract

The invention relates to the technical field of photoetching imaging, and discloses an illumination imaging method and device, exposure equipment and a medium. The method comprises the following steps: irradiating at least two beams of plane waves to a mask surface, performing coherence superposition on complex amplitude distribution of the same beam of plane waves on an image plane after passing through each preset area on the mask surface to obtain complex amplitude distribution of the plane waves on the image plane, and obtaining light intensity distribution of the plane waves on the image plane based on the complex amplitude distribution; and carrying out incoherent superposition on the light intensity distribution corresponding to all plane waves in the image plane to obtain an imaging result. The non-coherent plane wave imaging method is utilized, the miscellaneous degree of an imaging system is greatly reduced, the design of a complex projection objective lens system is avoided, the imaging characteristics of a single beam of coherent plane waves and multiple beams of non-coherent plane waves are combined, the imaging quality is improved through a simple and easy-to-implement mode, speckles in imaging are eliminated, and the imaging precision is improved. And the imaging resolution is improved.

Description

Technical Field

[0001] The present invention relates to the field of photolithography imaging technology, and in particular to an illumination imaging method, device, exposure equipment and medium. Background Art

[0002] Photolithography is a core technology in the field of integrated circuit chip processing. Traditional chip processing and manufacturing usually uses projection lithography, that is, after the light source illuminates the mask, the mask image is projected onto the silicon substrate coated with photoresist through a large and complex projection objective system to achieve imaging. In this scheme, the resolution is determined by the process factor, the effective numerical aperture of the projection objective, and the wavelength of the light source. For the same incident light source, the means to improve the resolution is often to increase the effective numerical aperture of the projection objective, which means that the complicated projection objective system must be continuously improved. At present, as the feature size of IC chips decreases year by year, the projection system in projection lithography is becoming more and more complex and huge, which poses a great challenge to research and development and manufacturing.

[0003] Another lithography scheme can avoid the use of such a complicated projection system, that is, a lithography scheme based on the principle of holographic imaging, in which the mask used is a holographic mask obtained in advance through calculation, and a spatial real image can be obtained at the expected position by illuminating the mask with a coherent light source. In the lithography scheme based on the principle of holographic imaging, the requirements for the objective lens system are greatly reduced, and the system redundancy is reduced due to the use of the diffraction imaging principle. However, when a high-coherence laser is used to illuminate a surface with a complex structure such as a holographic mask, its transmitted light field will produce a random spatial complex amplitude distribution, presenting a noise-like granular structure or a light and dark pattern, namely laser speckle, which seriously affects the imaging quality. In addition, under this illumination scheme, it is also difficult to improve the resolution.

[0004] Therefore, how to eliminate laser speckle and improve imaging resolution has become a problem that needs to be solved. Summary of the invention

[0005] In view of this, the present invention provides an illumination imaging method, device, exposure equipment and medium to solve the problems of laser speckle and low resolution in current imaging.

[0006] In a first aspect, the present invention provides an illumination imaging method for photolithography exposure, the method comprising:

[0007] When at least two plane waves irradiate at least one preset area of ​​the mask surface, the complex amplitude distribution of each plane wave on the image plane after passing through each preset area is obtained respectively; the complex amplitude distribution of the preset plane wave on the image plane after passing through each preset area is coherently superimposed to obtain the complex amplitude distribution of the preset plane wave on the image plane, and the preset plane wave is any one of the at least two plane waves; based on the complex amplitude distribution of the preset plane wave on the image plane, the light intensity distribution corresponding to the preset plane wave on the image plane is determined; the light intensity distribution corresponding to each plane wave on the image plane is incoherently superimposed to obtain an imaging result.

[0008] The illumination imaging method provided by the embodiment of the present invention irradiates at least two plane waves onto the mask surface, and performs coherent superposition on the complex amplitude distribution of the same plane wave on the image plane after passing through each preset area on the mask surface, so as to obtain the complex amplitude distribution of the plane wave on the image plane, and obtain the light intensity distribution of the plane wave on the image plane based on the complex amplitude distribution. Then, the light intensity distribution corresponding to each plane wave is incoherently superimposed to obtain the final imaging result. The present invention utilizes the above imaging method, which greatly reduces the complexity of the imaging system compared with the traditional projection imaging method, avoids the design of a complex projection objective lens system, and thus avoids the problem of supply chain shortage. Most importantly, compared with the single-beam imaging solution, the present invention combines the characteristics of plane wave coherence and incoherence, improves the imaging quality in a simple and easy-to-implement manner, eliminates speckle in imaging, and improves the imaging resolution. Specifically, the present invention improves the incoherence of the light wave by providing at least two plane waves for imaging, thereby achieving the purpose of eliminating speckle. In the provided incoherent plane waves, providing a plane wave with better coherence helps to improve the imaging resolution.

[0009] In an optional embodiment, the plane waves exist in pairs, and the projections of the two plane waves in the pair on the mask surface are respectively the same as the first angle formed by the first coordinate axis preset on the mask surface, and the two plane waves in the pair are respectively the same as the second angle formed by the second coordinate axis preset on the mask surface.

[0010] In an optional implementation, respectively acquiring the complex amplitude distribution of each plane wave on the image plane after passing through each preset area includes:

[0011] According to the Rayleigh-Sommerfeld diffraction rule, a first complex amplitude distribution on the image plane is obtained after the first plane wave passes through a preset area. Based on a preset conversion rule, the first complex amplitude distribution is converted to obtain a second complex amplitude distribution, which is the complex amplitude distribution on the image plane after the second plane wave passes through the preset area. The first plane wave and the second plane wave are two plane waves existing in pairs.

[0012] In an optional implementation, obtaining a first complex amplitude distribution on an image plane after the first plane wave passes through a preset area by using the Rayleigh-Sommerfeld diffraction rule includes:

[0013] The wave information corresponding to the first plane wave matching the Rayleigh-Sommerfeld diffraction rule and the area information corresponding to the preset area are obtained; based on the wave information and the area information, the first complex amplitude distribution on the image plane after the first plane wave passes through the preset area is determined.

[0014] In an optional implementation, based on a preset conversion rule, converting the first complex amplitude distribution to obtain a second complex amplitude distribution includes:

[0015] A first amplitude and a first phase corresponding to the first complex amplitude distribution are obtained; the amplitude corresponding to the first complex amplitude distribution is rotated by a preset angle to obtain a second amplitude; and a second complex amplitude distribution is obtained based on the second amplitude and the first phase.

[0016] The illumination imaging method provided by the embodiment of the present invention realizes the conversion of the complex amplitude distribution corresponding to the paired plane waves through a preset conversion rule, and no second complex amplitude distribution needs to be determined by other means, thus saving computing resources. When storing the complex amplitude distribution data, since the complex amplitude distributions can be converted to each other, only one set of complex amplitude distribution data needs to be stored, thus saving storage space and speeding up the program running speed.

[0017] In an optional embodiment, before the at least two plane waves are irradiated onto at least one preset area of ​​the mask surface, the method further includes:

[0018] When the light beam generated by the light source is a Gaussian wave, the Gaussian wave is modulated to generate a plane wave.

[0019] In a second aspect, the present invention provides an illumination imaging device, which includes a complex amplitude acquisition module, a coherent superposition module, a light intensity determination module and an incoherent superposition module.

[0020] The complex amplitude acquisition module is used to obtain the complex amplitude distribution of each plane wave on the image plane after passing through each preset area when at least two plane waves are irradiated to at least one preset area of ​​the mask surface; the coherent superposition module is used to coherently superpose the complex amplitude distribution of the preset plane wave on the image plane after passing through each preset area, so as to obtain the complex amplitude distribution of the preset plane wave on the image plane, and the preset plane wave is any one of the at least two plane waves; the light intensity determination module is used to determine the light intensity distribution corresponding to the preset plane wave on the image plane based on the complex amplitude distribution of the preset plane wave on the image plane; the incoherent superposition module is used to incoherently superpose the light intensity distribution corresponding to each plane wave on the image plane, so as to obtain the imaging result.

[0021] In an optional embodiment, the plane waves in the complex amplitude acquisition module exist in pairs, and the projections of the two paired plane waves on the mask surface are respectively the same as the first angles formed by the first coordinate axis preset on the mask surface, and the two paired plane waves are respectively the same as the second angles formed by the second coordinate axis preset on the mask surface.

[0022] In a third aspect, the present invention provides an exposure device for use in a chip preparation process, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, computer instructions being stored in the memory, and the processor executing the illumination imaging method of the first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0023] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the illumination imaging method of the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 is a schematic flow chart of an illumination imaging method according to an embodiment of the present invention;

[0026] Figure 2 is a schematic structural diagram of an imaging simulation system according to an embodiment of the present invention;

[0027] Figure 3 is a schematic diagram of a spatial coordinate system established on a mask surface according to an embodiment of the present invention;

[0028] Figure 4 is a schematic diagram of imaging results of a single plane wave normal incidence mask according to an embodiment of the present invention;

[0029] Figure 5 is a schematic diagram of imaging results of a dual-plane wave oblique-incidence mask according to an embodiment of the present invention;

[0030] Figure 6 is a schematic flow chart of another illumination imaging method according to an embodiment of the present invention;

[0031] Figure 7 is a schematic diagram of complex amplitude distribution of a first plane wave incident on a single preset area according to an embodiment of the present invention;

[0032] Figure 8 is a schematic diagram of complex amplitude distribution of a second plane wave incident on a single preset area according to an embodiment of the present invention;

[0033] Fig. 9 is a schematic structural diagram of an illumination imaging device according to an embodiment of the present invention;

[0034] Fig.10 It is a schematic diagram of the hardware structure of the exposure device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0036] When a high-coherence laser is used to irradiate the surface of a holographic mask, not only laser speckles are generated, which affects the imaging quality, but also leads to low resolution, which is difficult to improve. Therefore, an embodiment of the present invention provides an illumination imaging method and device, which illuminates the mask surface with an incoherent plane wave, thereby generating a final imaging result through the coherent superposition of complex amplitudes and the incoherent superposition of light intensity distribution, so as to completely eliminate laser speckles and improve the imaging resolution.

[0037] According to an embodiment of the present invention, an embodiment of an illumination imaging method is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0038] In an embodiment of the present invention, an illumination imaging method is provided for photolithography exposure, which can be specifically used for exposure equipment. Figure 1 is a flow chart of an illumination imaging method according to an embodiment of the present invention. Figure 1 As shown, the process includes the following steps:

[0039] Step S101 : when at least two plane waves irradiate at least one preset area of ​​the mask surface, respectively obtain the complex amplitude distribution of each plane wave on the image plane after passing through each preset area.

[0040] Specifically, the embodiment of the present invention completes the final imaging by simulating the imaging process of the imaging system. In the imaging simulation system, the positional relationship between the plane wave, the mask surface and the image plane is as follows: Figure 2 As shown, Figure 2 The system includes a first light source 1, a second light source 2, a first lens 3, a second lens 4, a mask surface 5 and an image plane 6. After the two light sources Source1 and Source2 generate light beams, they pass through the lenses Lens respectively, and the light beams are adjusted into plane waves and irradiated to the mask surface 5. After the two plane waves pass through the preset area of ​​the mask surface 5, complex amplitude distributions corresponding to each plane wave are generated on the image plane 6.

[0041] Specifically, at least two plane waves are plane waves emitted from two different directions, i.e., incoherent plane waves. After the incoherent plane waves pass through the preset area, complex amplitude distributions corresponding to the incoherent plane waves are obtained on the image plane. The complex amplitude distribution can be directly obtained after calculation, and the calculation method can be Rayleigh-Sommerfield, Fresnel diffraction, Fraunhofer diffraction, etc.

[0042] Specifically, the preset area is a preset small hole on the mask surface.

[0043] Exemplarily, the complex amplitude distribution in this embodiment includes the complex amplitude distribution on the image plane after each light beam passes through each preset area of ​​the mask surface. For example, two plane waves are irradiated to the mask surface, and there are three small holes on the mask surface. Since each plane wave will have a corresponding complex amplitude distribution on the image plane when passing through each small hole, therefore, in the embodiment of the present invention, the first plane wave has three corresponding complex amplitude distributions on the image plane when passing through the three small holes, and the second plane wave has three corresponding complex amplitude distributions on the image plane when passing through the three small holes, and finally a total of 6 complex amplitude distributions are obtained.

[0044] For example, in another optional embodiment, the plane waves exist in pairs, and the projections of the two plane waves in the pair on the mask surface respectively form the same first angle with the first coordinate axis preset on the mask surface, and the two plane waves in the pair respectively form the same second angle with the second coordinate axis preset on the mask surface. Figure 3 As shown, a space coordinate system is established with the center O of the mask surface as the coordinate origin, and in the embodiment of the present invention, the first coordinate axis is preset as the x-axis, and the second coordinate axis is preset as the z-axis. That is, the projections of the two paired plane waves on the mask surface respectively form the same first angle with the x-axis, and the second angles formed by the two paired plane waves and the z-axis are also the same.

[0045] Exemplarily, when the light beam generated by the light source is a Gaussian wave, the Gaussian wave is modulated to generate a plane wave. Figure 2 In this method, the Gaussian wave generated by the light source is modulated into a plane wave using a lens.

[0046] Step S102 , coherently superimposing the complex amplitude distributions of the preset plane wave on the image plane after the preset plane wave passes through each preset area, to obtain the complex amplitude distribution of the preset plane wave on the image plane.

[0047] Specifically, the preset plane wave is any one of at least two plane waves, and multiple complex amplitude distributions of a certain plane wave on the image plane are coherently superimposed after passing through each preset area to obtain a complex amplitude distribution of the plane wave on the image plane.

[0048] Exemplarily, when there is only one preset area on the mask surface, the two sets of complex amplitude distributions generated on the image plane after at least two plane waves pass through the preset area are incoherent. Therefore, when there is only one preset area on the mask surface, coherent superposition is not required.

[0049] Exemplarily, when there are at least two preset areas on the mask surface, the complex amplitude distributions corresponding to the preset plane wave on the image plane after passing through each preset area are coherent. Therefore, it is necessary to coherently superimpose the complex amplitude distributions of the preset plane wave on the image plane after passing through each preset area to obtain the complex amplitude distribution of the preset plane wave on the image plane. Since coherent superposition is a physical phenomenon related to the coherence of the light source, the coherent superposition operation can be realized by simulating the wave information of the plane wave. The simulation process of coherent superposition is not described in detail here, and those skilled in the art can use existing simulation methods to achieve it.

[0050] Step S103, based on the complex amplitude distribution of the preset plane wave on the image plane, determining the light intensity distribution corresponding to the preset plane wave on the image plane.

[0051] Exemplarily, the light intensity distribution corresponding to the preset plane wave is determined in the following manner.

[0052]

[0053] Among them, I l (x, y, z) is the light intensity distribution corresponding to the preset plane wave on the image plane, U l (x,y,z) is the pair U l1 to U lN The complex amplitude distribution of the lth plane wave (i.e., the preset plane wave) on the image plane after the coherent superposition operation, U li is the complex amplitude distribution of the lth plane wave (i.e., the preset plane wave) on the image plane after passing through the ith preset area, N is the number of preset areas on the mask surface, and the summation operation in the formula is the coherent superposition operation.

[0054] Step S104, performing incoherent superposition on the light intensity distribution corresponding to each plane wave on the image plane to obtain an imaging result.

[0055] Specifically, the light intensity distribution corresponding to each plane wave is incoherently superimposed to obtain the final imaging result.

[0056] Exemplarily, the total light intensity distribution on the image plane is determined in the following manner, where the total light intensity distribution is the imaging result obtained after an incoherent superposition operation is performed on the light intensity distributions corresponding to the plane waves.

[0057]

[0058] Among them, I(x,y,z) is the total light intensity distribution on the image plane after each plane wave passes through the mask surface, I l is the light intensity distribution of the lth plane wave on the image plane. M is the number of plane waves, and the summation operation in the formula is the incoherent superposition operation.

[0059] For example, with the goal of forming a 22 μm×22 μm image, when a single plane wave is incident normally on the mask surface, the following is obtained: Figure 4 When two plane waves are incident on the mask surface obliquely in the manner provided in the embodiment of the present invention, the following imaging result is obtained: Figure 5 The imaging results are shown. Figure 4 In the figure, several holes can be clearly observed in the thicker lines (i.e. Figure 4 There are multiple circles in the wider rectangular strips), the line uniformity is poor, the resolution is poor, and there are obvious light and dark speckles in the lines. Figure 4 compared to, Figure 5 The imaging quality is significantly improved, speckle is completely eliminated, holes are suppressed, and the uniformity and resolution of lines are improved. The reason why the method provided by the present invention can eliminate speckle and improve resolution is that the main reason for the generation of speckle is that the laser coherence is very high. Therefore, the present invention provides at least two incoherent plane waves to increase the incoherence of the light wave, thereby achieving the purpose of reducing or eliminating speckle. Among the acquired incoherent plane waves, providing a plane wave with better coherence helps to improve the resolution of imaging.

[0060] The illumination imaging method provided by the embodiment of the present invention irradiates at least two plane waves onto the mask surface, and coherently superimposes the complex amplitude distribution of the same plane wave on the image plane after passing through each preset area on the mask surface, so as to obtain the complex amplitude distribution of the plane wave on the image plane, and obtains the light intensity distribution of the plane wave on the image plane based on the complex amplitude distribution. Then, the light intensity distribution corresponding to each plane wave is incoherently superimposed to obtain the final imaging result. Compared with the traditional projection imaging method, the present invention utilizes the above imaging method to greatly reduce the complexity of the imaging system, avoid the design of a complex projection objective system, and thus circumvent the problem of supply chain shortage. Most importantly, compared with the single-beam imaging solution, the present invention combines the coherence and incoherence characteristics of the plane wave, improves the imaging quality in a simple and easy-to-implement manner, eliminates the speckle in the imaging, and improves the imaging resolution. Specifically, the present invention improves the incoherence of the light wave by providing at least two plane waves for imaging, thereby achieving the purpose of eliminating speckle. Among multiple plane wave beams, using a single plane wave with good coherence and the incoherence between the plane waves helps to improve the imaging resolution.

[0061] In an embodiment of the present invention, a lighting imaging method is provided, which can be used for an exposure device. Figure 6 is a flow chart of an illumination imaging method according to an embodiment of the present invention. Figure 6 As shown, the process includes the following steps:

[0062] Step S601 : when at least two plane waves irradiate at least one preset area of ​​the mask surface, the complex amplitude distribution of each plane wave on the image plane after passing through each preset area is obtained respectively.

[0063] Specifically, the above step S601 includes:

[0064] Step S6011, obtaining a first complex amplitude distribution on an image plane after the first plane wave passes through a preset area according to the Rayleigh-Sommerfeld diffraction rule.

[0065] In some optional implementations, the first complex amplitude distribution of the first plane wave on the image plane after passing through the preset area is obtained by using the Rayleigh-Sommerfeld diffraction rule, and the determination process includes:

[0066] Step a1, obtaining wave information corresponding to a first plane wave matching the Rayleigh-Sommerfeld diffraction rule and region information corresponding to a preset region.

[0067] Specifically, the wave information includes the wavelength of the plane wave, the wave number of the plane wave, the cosine value of the first angle formed by the projection of the plane wave on the mask surface and the x-axis, and the cosine value of the second angle formed by the projection of the plane wave on the mask surface and the y-axis. Figure 3 .

[0068] Specifically, the region information includes the distance between the mask surface and the preset phase plane, the center coordinates of the preset region, the size of the mask surface region, and the mask surface structure.

[0069] Step a2: determining a first complex amplitude distribution on the image plane after the first plane wave passes through a preset area based on the wave information and the area information.

[0070] Specifically, the Rayleigh-Sommerfeld diffraction rule is the Rayleigh-Sommerfeld diffraction formula, which is as follows:

[0071]

[0072] Wherein, U(x, y, z) is the complex amplitude distribution of the plane wave on the image plane after passing through the preset area (i.e., the first complex amplitude distribution), λ is the wavelength of the plane wave, j is the imaginary unit, N is the number of preset areas on the mask surface, and R i is the i-th preset area of ​​the mask surface, A i is the amplitude of the i-th preset area on the mask surface, φ i is the phase of the i-th preset area on the mask surface, (ξ, η) is the coordinate relative to the center of the preset area on the mask surface, is the absolute coordinate of the center of the i-th preset area, k is the wave number, k = 2π / λ, α is the cosine value of the angle formed by the plane wave and the x-axis on the mask surface, and β is the cosine value of the angle formed by the plane wave and the y-axis on the mask surface.

[0073] The embodiment of the present invention calculates the complex amplitude distribution through Rayleigh-Sommerfeld diffraction integral, and the calculation method used is simpler and more efficient, thereby improving the imaging efficiency.

[0074] Step S6012: based on a preset conversion rule, convert the first complex amplitude distribution to obtain a second complex amplitude distribution.

[0075] Specifically, the second complex amplitude distribution is the complex amplitude distribution on the image plane after the second plane wave passes through the preset area.

[0076] Specifically, the first plane wave and the second plane wave are two plane waves existing in pairs.

[0077] Exemplarily, the preset conversion rule is determined as follows:

[0078] Figure 7 is the distribution of the real part of the complex amplitude on the image plane after the first plane wave is incident on a single preset area (i.e., the first complex amplitude distribution), Figure 7 In the figure, the alternating light and dark stripes correspond to the phase distribution, and the overall brightness change of the image corresponds to the amplitude distribution. Figure 8 is the distribution of the real part of the complex amplitude of the second plane wave on the image plane after it is incident on the above-mentioned preset area (i.e., the second complex amplitude distribution). Figure 7 and Figure 8 It can be found that the phase of the complex amplitude distribution is consistent, but the amplitude distribution is different. Figure 7 The upper left corner is brighter, while Figure 8 The lower right corner of is brighter, corresponding to the angle between the first plane wave and the second plane wave on the x-axis and the y-axis. Thus, the preset conversion rule can be obtained. The preset conversion rule avoids multiple calculations of the complex amplitude distribution. In addition, since the phases of the complex amplitude distributions corresponding to the paired plane waves are centrally symmetrically distributed and have the same amplitude, the embodiment of the present invention can store one quarter of the phase when storing the phase, thereby saving storage space. Theoretically, it is allowed to store one three hundred and sixty tenth of the phase.

[0079] In some optional implementations, the above step S6012 specifically includes:

[0080] Step b1, obtaining a first amplitude and a first phase corresponding to a first complex amplitude distribution.

[0081] Step b2: rotating the amplitude corresponding to the first complex amplitude distribution by a preset angle to obtain a second amplitude.

[0082] For example, according to Figure 7 and Figure 8 It can be seen that the preset angle is 180°.

[0083] Step b3, obtaining a second complex amplitude distribution based on the second amplitude and the first phase. Specifically, the second complex amplitude distribution can be obtained by multiplying the second amplitude by the first phase.

[0084] Step S602, coherently superimpose the complex amplitude distribution of the preset plane wave on the image plane after it passes through each preset area to obtain the complex amplitude distribution of the preset plane wave on the image plane. Figure 1 Step S102 of the illustrated embodiment will not be described in detail here.

[0085] Step S603, based on the complex amplitude distribution of the preset plane wave on the image plane, determine the light intensity distribution corresponding to the preset plane wave on the image plane. Figure 1 Step S103 of the illustrated embodiment will not be described in detail here.

[0086] Step S604, incoherently superimpose the light intensity distribution corresponding to each plane wave on the image plane to obtain an imaging result. Figure 1 Step S103 of the illustrated embodiment will not be described in detail here.

[0087] In an embodiment of the present invention, a lighting imaging device is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and the descriptions that have been made will not be repeated. As used below, the term "device" can implement a combination of software and / or hardware of a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0088] An embodiment of the present invention provides a lighting imaging device, such as Fig. 9 As shown, the device includes the following modules: a complex amplitude acquisition module 901, a coherent superposition module 902, a light intensity determination module 903 and an incoherent superposition module 904.

[0089] The complex amplitude acquisition module 901 is used to respectively acquire the complex amplitude distribution of each plane wave on the image plane after passing through each preset area when at least two plane waves irradiate at least one preset area of ​​the mask surface.

[0090] The coherent superposition module 902 is used to coherently superpose the complex amplitude distribution of the preset plane wave on the image plane after passing through each preset area to obtain the complex amplitude distribution of the preset plane wave on the image plane, where the preset plane wave is any one of at least two plane waves.

[0091] The light intensity determination module 903 is used to determine the light intensity distribution corresponding to the preset plane wave on the image plane based on the complex amplitude distribution of the preset plane wave on the image plane.

[0092] The incoherent superposition module 904 is used to perform incoherent superposition on the light intensity distribution corresponding to each plane wave on the image plane to obtain an imaging result.

[0093] In an optional embodiment, the plane waves in the complex amplitude acquisition module 901 exist in pairs, and the projections of the two paired plane waves on the mask surface are respectively the same as the first angles formed by the first coordinate axis preset on the mask surface, and the two paired plane waves are respectively the same as the second angles formed by the second coordinate axis preset on the mask surface.

[0094] In an optional implementation, the complex amplitude acquisition module 901 includes an acquisition submodule and a conversion submodule.

[0095] The acquisition submodule is used to obtain the first complex amplitude distribution on the image plane after the first plane wave passes through the preset area through the Rayleigh-Sommerfeld diffraction rule.

[0096] The conversion submodule is used to convert the first complex amplitude distribution based on a preset conversion rule to obtain a second complex amplitude distribution, where the second complex amplitude distribution is the complex amplitude distribution on the image plane after the second plane wave passes through a preset area; the first plane wave and the second plane wave are two plane waves existing in pairs.

[0097] In an optional implementation, the acquisition submodule includes a first acquisition unit and a first determination unit.

[0098] The first acquisition unit is used to acquire wave information corresponding to a first plane wave matching the Rayleigh-Sommerfeld diffraction rule and region information corresponding to a preset region.

[0099] The first determination unit is used to determine a first complex amplitude distribution on an image plane after the first plane wave passes through a preset area based on the wave information and the area information.

[0100] In an optional implementation, the conversion submodule includes a second acquisition unit, a second determination unit, and a third determination unit.

[0101] The second acquisition unit is used to acquire a first amplitude and a first phase corresponding to the first complex amplitude distribution.

[0102] The second determining unit is used to rotate the amplitude corresponding to the first complex amplitude distribution by a preset angle to obtain a second amplitude.

[0103] The third determining unit is configured to obtain a second complex amplitude distribution based on the second amplitude and the first phase.

[0104] In an optional implementation, before the complex amplitude acquisition module 901, the following steps are also included:

[0105] The waveform modulation module is used to modulate the Gaussian wave to generate a plane wave when the light beam generated by the light source is a Gaussian wave.

[0106] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0107] The lighting imaging device in the embodiment of the present invention is presented in the form of a functional unit, where the unit refers to an application specific integrated circuit (ASIC), a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0108] The embodiment of the present invention further provides an exposure device, which is applied to the chip preparation process. The exposure device of the embodiment of the present invention can be a photolithography device with a computer processing function, or a computer device with a photolithography function. Fig. 9 The processing device shown.

[0109] See also Fig.10 , Fig.10 is a schematic structural diagram of an exposure device provided by an optional embodiment of the present invention, such as Fig.10As shown, the exposure device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. The various components are connected to each other using different buses for communication, and can be installed on a common motherboard or installed in other ways as needed. The processor can process instructions executed in the exposure device, including instructions stored in or on the memory to display graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple exposure devices can be connected, and each device provides part of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Fig.10 A processor 10 is taken as an example.

[0110] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0111] The memory 20 stores instructions executable by at least one processor 10, so that at least one processor 10 executes the method shown in the above embodiment.

[0112] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required by at least one function; the data storage area may store data created according to the use of the exposure device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the exposure device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0113] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0114] The exposure device further includes a communication interface 30 for the exposure device to communicate with other devices or a communication network.

[0115] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0116] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. An illumination imaging method for photolithography exposure, characterized in that: The method comprises: When at least two plane waves irradiate at least one preset area of ​​the mask surface, respectively obtain the complex amplitude distribution of each plane wave on the image plane after passing through each preset area; Performing coherent superposition on the complex amplitude distribution of a preset plane wave on the image plane after the preset plane wave passes through each of the preset areas to obtain the complex amplitude distribution of the preset plane wave on the image plane, wherein the preset plane wave is any one of the at least two plane waves; Determining the light intensity distribution corresponding to the preset plane wave on the image plane based on the complex amplitude distribution of the preset plane wave on the image plane; The light intensity distribution corresponding to each beam of the plane wave on the image plane is incoherently superimposed to obtain an imaging result.

2. The method according to claim 1, characterized in that The plane waves exist in pairs, and the projections of the two plane waves in pairs on the mask surface are respectively the same as the first angles formed by the first coordinate axis preset on the mask surface, and the second angles formed by the two plane waves in pairs are respectively the same as the second angles formed by the second coordinate axis preset on the mask surface.

3. The method according to claim 1 or 2, characterized in that: The step of respectively acquiring the complex amplitude distribution of each beam of the plane wave on the image plane after the beam passes through each of the preset areas comprises: Obtaining, by using the Rayleigh-Sommerfeld diffraction rule, a first complex amplitude distribution of the first plane wave on the image plane after the first plane wave passes through the preset area; Based on a preset conversion rule, convert the first complex amplitude distribution to obtain a second complex amplitude distribution, where the second complex amplitude distribution is a complex amplitude distribution on the image plane after the second plane wave passes through the preset area; The first plane wave and the second plane wave are two plane waves existing in pairs.

4. The method according to claim 3, characterized in that The step of obtaining the first complex amplitude distribution of the first plane wave on the image plane after the first plane wave passes through the preset area by using the Rayleigh-Sommerfeld diffraction rule comprises: Acquire wave information corresponding to the first plane wave and region information corresponding to the preset region that match the Rayleigh-Sommerfeld diffraction rule; Based on the wave information and the region information, a first complex amplitude distribution of the first plane wave on the image plane after the first plane wave passes through the preset region is determined.

5. The method according to claim 3, characterized in that: The converting the first complex amplitude distribution based on a preset conversion rule to obtain a second complex amplitude distribution includes: Acquire a first amplitude and a first phase corresponding to the first complex amplitude distribution; Rotating the amplitude corresponding to the first complex amplitude distribution by a preset angle to obtain a second amplitude; The second complex amplitude distribution is obtained based on the second amplitude and the first phase.

6. The method according to claim 1, characterized in that Before the at least two plane waves are irradiated onto at least one preset area of ​​the mask surface, the method further comprises: When the light beam generated by the light source is a Gaussian wave, the Gaussian wave is modulated to generate the plane wave.

7. A lighting imaging device, characterized in that: The device comprises: A complex amplitude acquisition module, used for respectively acquiring the complex amplitude distribution of each plane wave on the image plane after passing through each preset area when at least two plane waves irradiate at least one preset area of ​​the mask surface; a coherent superposition module, configured to coherently superpose the complex amplitude distribution of a preset plane wave on the image plane after the preset plane wave passes through each of the preset areas, so as to obtain the complex amplitude distribution of the preset plane wave on the image plane, wherein the preset plane wave is any one of the at least two plane waves; A light intensity determination module, used to determine the light intensity distribution corresponding to the preset plane wave on the image plane based on the complex amplitude distribution of the preset plane wave on the image plane; The incoherent superposition module is used to perform incoherent superposition on the light intensity distribution corresponding to each beam of the plane wave on the image plane to obtain an imaging result.

8. The device according to claim 7, characterized in that The plane waves in the complex amplitude acquisition module exist in pairs, and the projections of the two plane waves in the pair on the mask surface are respectively the same as the first angles formed by the first coordinate axis preset on the mask surface, and the second angles formed by the two plane waves in the pair are respectively the same as the second angles formed by the second coordinate axis preset on the mask surface.

9. An exposure device, applied to a chip preparation process, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the illumination imaging method according to any one of claims 1 to 6 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the illumination imaging method according to any one of claims 1 to 6.

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