Uniform light control method, fly's-eye lens unit and photoetching system

Abstract

The invention provides a dodging control method, a fly's-eye lens unit and a photoetching system. According to the method, the fly's-eye lens unit corresponding to a light source is arranged in the photoetching system based on light spot incidence parameters corresponding to the LED ultraviolet light source; wherein the fly's-eye lens unit comprises double rows of fly's-eye lenses and condensing lenses; then acquiring a first focal length corresponding to the double-row fly's-eye lens, a first position distance between the double-row fly's-eye lens and the condensing lens and a second focal length of the condensing lens, and determining a first incident angle and an incident height corresponding to the LED ultraviolet light source by using a light spot incident parameter; calculating a second incident angle and a light spot size corresponding to the imaging surface of the light source based on the first incident angle, the incident height, the first focal length, the first position spacing and the second focal length; and finally, controlling a light spot divergence angle corresponding to the LED ultraviolet light source according to the second incident angle and the light spot size. According to the scheme, the LED ultraviolet light source is applied to the DMD photoetching system to serve as the exposure light source, the light path is simple, and control is efficient.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of light source control, in particular to a light homogenization control method, compound eye lens unit and photolithography system. BACKGROUND

[0002] The exposure light source provides an illumination light beam with uniform light intensity distribution for the whole photolithography system, and is one of the core technologies of the projection photolithography machine. The illumination uniformity directly affects the uniformity of the exposure line width and the consistency of the single-field exposure area resolution, and plays an important role in the photolithography system. Similar to the traditional ultraviolet exposure, the high-pressure mercury lamp, the laser ultraviolet light source and the LED ultraviolet light source can all be used as the exposure light source of the DMD (Digital Micromirror Devices) photolithography system. However, the high-pressure mercury lamp light source has a complex structure and poor performance; the laser ultraviolet light source involves a laser, which is prone to serious speckle due to coherence, and needs to be additionally provided with a complex speckle elimination device; and the LED ultraviolet light source lacks a corresponding implementation means when used as the exposure light source in the photolithography system. SUMMARY

[0003] Therefore, the purpose of the present application is to provide a light homogenization control method, compound eye lens unit and photolithography system, which realizes the application of the LED ultraviolet light source as the exposure light source in the DMD photolithography system, does not need a complex beam expander, has a simple light path and is easy to set and efficient in the control process.

[0004] In a first aspect, the present application provides a light homogenization control method, which is used for controlling the light spot divergence angle of an LED ultraviolet light source in a photolithography system; the method comprises the following steps: setting a compound eye lens unit corresponding to the LED ultraviolet light source in the photolithography system based on the light spot incidence parameters corresponding to the LED ultraviolet light source; wherein the compound eye lens unit comprises a double-row compound eye lens and a condenser lens; obtaining a first focal length corresponding to the double-row compound eye lens, a first position interval between the double-row compound eye lens and the condenser lens, and a second focal length of the condenser lens, and determining a first incidence angle and an incidence height corresponding to the LED ultraviolet light source by using the light spot incidence parameters; calculating a second incidence angle and a light spot size corresponding to the imaging surface of the LED ultraviolet light source based on the first incidence angle, the incidence height, the first focal length, the first position interval and the second focal length; controlling the light spot divergence angle corresponding to the LED ultraviolet light source according to the second incidence angle and the light spot size.

[0005] Optionally, the step of setting the compound eye lens unit corresponding to the LED ultraviolet light source in the photolithography system based on the light spot incidence parameters corresponding to the LED ultraviolet light source comprises the following steps: The size parameter is used to determine the number of sub-lenses in the double-row compound eye lens for imaging, and the first focal length corresponding to the double-row compound eye lens is determined based on the number of sub-lenses and the second position interval between the double-row compound eye lenses; The size parameter is used to determine the number of sub-lenses in the double-row compound eye lens for imaging, and the first focal length corresponding to the double-row compound eye lens is determined based on the number of sub-lenses and the second position interval between the double-row compound eye lenses; The size parameter is used to determine the position parameter between the condenser lens and the double-row compound eye lens, the first position interval between the double-row compound eye lens and the condenser lens is determined based on the position parameter, and the second focal length between the condenser lens and the imaging surface of the LED ultraviolet light source is determined based on the position parameter; The double-row compound eye lens corresponding to the compound eye lens unit in the photolithography system is set according to the first focal length and the first position interval, and the condenser lens corresponding to the compound eye lens unit in the photolithography system is set according to the second focal length and the first position interval.

[0006] Optionally, the first incidence angle and the incidence height corresponding to the LED ultraviolet light source are determined based on the spot incidence parameter, including: The optical axis corresponding to the compound eye lens unit is determined based on the double-row compound eye lens and the condenser lens, and the first incidence angle corresponding to the LED ultraviolet light source is determined based on the angle between the spot incidence parameter and the optical axis; The incidence height corresponding to the LED ultraviolet light source is determined according to the positional relationship between the spot size and the optical axis.

[0007] Optionally, the second incidence angle and the spot size corresponding to the imaging surface of the LED ultraviolet light source are calculated based on the first incidence angle, the incidence height, the first focal length, the first position interval and the second focal length, including: The sub-lens diameter in each row of the double-row compound eye lens is determined based on the number of sub-lenses; The coordinate offset corresponding to the LED ultraviolet light source is calculated based on the sub-lens diameter and the number of sub-lenses; The second incidence angle and the spot size corresponding to the imaging surface of the LED ultraviolet light source are calculated based on the first incidence angle, the incidence height, the first focal length, the first position interval, the second focal length and the coordinate offset.

[0008] Optionally, the second incidence angle and the spot size are calculated by the following formula: ; Wherein, is the second incidence angle; is the coordinate value corresponding to the spot size in the imaging surface; is the second focal length; is the first position interval; is the coordinate offset; is the number of sub-lenses; is the sub-lens diameter; is a first focal length; is a first incident angle; is an incident height.

[0009] Optionally, the calculation results of the second incident angle and the spot size are: .

[0010] Optionally, the step of controlling the spot divergence angle of the LED ultraviolet light source according to the second incident angle and the spot size comprises: calculating a numerical aperture of the fly-eye lens array by using the sub-lens diameter and the first focal length, and determining a boundary condition corresponding to the spot incident parameters based on the numerical aperture; determining a first corresponding relationship between the incident height and the sub-lens diameter based on the boundary condition, and updating the second incident angle and the spot size based on the first corresponding relationship; controlling the spot divergence angle to a minimum value according to the updated second incident angle and the spot size.

[0011] Optionally, when the boundary condition is that the maximum value of the first incident angle is equal to the numerical aperture and the first corresponding relationship is that the incident height is equal to half of the sub-lens diameter, the calculation results of the second incident angle and the spot size are: . controlling the first position interval equal to the second focal length so that the spot divergence angle reaches a minimum value.

[0012] In a second aspect, the present application provides a fly-eye lens unit, which at least comprises a double-row fly-eye lens and a condenser lens; wherein the fly-eye lens unit adopts the light uniformity control method mentioned in the first aspect in the process of controlling the spot divergence angle of the LED ultraviolet light source in the photoetching system.

[0013] In a third aspect, the present application provides a photoetching system, which is provided with an LED ultraviolet light source, and the LED ultraviolet light source adopts the fly-eye lens unit mentioned in the second aspect when eliminating the speckle of the imaging surface; and adopts the light uniformity control method mentioned in the first aspect in the process of using the fly-eye lens unit to control the light uniformity of the speckle.

[0014] In a fourth aspect, the present application provides a light uniformity control system, which is used for controlling the spot divergence angle of the LED ultraviolet light source in the photoetching system, and the light uniformity control system comprises: The first control module is configured to set a compound eye lens unit corresponding to the LED ultraviolet light source in the photolithography system based on a light spot incident parameter corresponding to the LED ultraviolet light source, wherein the compound eye lens unit comprises a double-row compound eye lens and a condenser lens. The second control module is configured to obtain a first focal length corresponding to the double-row compound eye lens, a first position interval between the double-row compound eye lens and the condenser lens, and a second focal length of the condenser lens, and determine a first incident angle and an incident height corresponding to the LED ultraviolet light source by using the light spot incident parameter. The third control module is configured to calculate a second incident angle and a light spot size corresponding to an imaging surface of the LED ultraviolet light source based on the first incident angle, the incident height, the first focal length, the first position interval, and the second focal length. The fourth control module is configured to control a light spot divergence angle corresponding to the LED ultraviolet light source according to the second incident angle and the light spot size.

[0015] In a fifth aspect, an electronic device is provided, which includes a processor and a memory. The memory stores computer executable instructions capable of being executed by the processor. The processor executes the computer executable instructions to implement the steps of the light homogenization control method provided in the first aspect.

[0016] In a sixth aspect, a storage medium is provided, which stores computer executable instructions. When the computer executable instructions are invoked and executed by a processor, the computer executable instructions cause the processor to implement the steps of the light homogenization control method provided in the first aspect.

[0017] The light homogenization control method, the compound eye lens unit, and the photolithography system provided in the embodiments of the present application can be used to control the light spot divergence angle of the LED ultraviolet light source in the photolithography system. In the process of controlling the light spot divergence angle of the LED ultraviolet light source in the photolithography system, the method first sets a compound eye lens unit corresponding to the LED ultraviolet light source in the photolithography system based on a light spot incident parameter corresponding to the LED ultraviolet light source, wherein the compound eye lens unit comprises a double-row compound eye lens and a condenser lens. Then, a first focal length corresponding to the double-row compound eye lens, a first position interval between the double-row compound eye lens and the condenser lens, and a second focal length of the condenser lens are obtained, and a first incident angle and an incident height corresponding to the LED ultraviolet light source are determined by using the light spot incident parameter. Subsequently, a second incident angle and a light spot size corresponding to an imaging surface of the LED ultraviolet light source are calculated based on the first incident angle, the incident height, the first focal length, the first position interval, and the second focal length. Finally, a light spot divergence angle corresponding to the LED ultraviolet light source is controlled according to the second incident angle and the light spot size. The present application realizes the application of the LED ultraviolet light source in the DMD photolithography system as an exposure light source, does not need a complex beam expander, and has a simple optical path, is easy to set, and has an efficient control process.

[0018] Other features and advantages of the present application will be set forth in the descriptions that follow, and in part will be apparent from the description, or can be learned by practice of the application. The purposes and other advantages of the application will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

[0019] In order to make the above objectives, features and advantages of the present application more apparent, the following will describe a preferred embodiment in detail, and the accompanying drawings will be described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without any creative effort.

[0021] Figure 1 A flow chart of a uniform light control method provided by an embodiment of the present application; Figure 2 A flow chart of step S101 in a uniform light control method provided by an embodiment of the present application; Figure 3 A flow chart of using the light spot incident parameter to determine the first incident angle and incident height corresponding to the LED ultraviolet light source in a uniform light control method provided by an embodiment of the present application; Figure 4 A flow chart of step S103 in a uniform light control method provided by an embodiment of the present application; Figure 5 A flow chart of step S104 in a uniform light control method provided by an embodiment of the present application; Figure 6 A schematic structural diagram of a compound eye lens unit provided by an embodiment of the present application; Figure 7 A schematic structural diagram of a uniform light control system provided by an embodiment of the present application; Figure 8 A schematic structural diagram of an electronic device provided by an embodiment of the present application.

[0022] Icon: 710-first control module; 720-second control module; 730-third control module; 740-fourth control module; 101-processor; 102-memory; 103-bus; 104-communication interface. DETAILED DESCRIPTION

[0023] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the present application will be described clearly and completely below in conjunction with embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0024] The exposure light source provides an illumination light beam with uniform light intensity distribution for the whole photolithography system, and is one of the core technologies of the projection photolithography machine. The illumination uniformity directly affects the uniformity of the exposure line width and the consistency of the single-field exposure area resolution, and plays an important role in the photolithography system. Similar to the traditional ultraviolet exposure, the high-pressure mercury lamp, the laser ultraviolet light source and the LED ultraviolet light source can all be used as the exposure light source of the DMD (Digital Micromirror Devices) photolithography system.

[0025] The high-pressure mercury lamp is a light source that emits light by using the electroluminescence effect. The high-pressure mercury lamp emits light through the high-pressure mercury vapor discharge released during the discharge, and the inside of the discharge tube is filled with argon for starting and mercury for discharging. The high-pressure mercury lamp has very high irradiance and a relatively wide spectral range, including the 435.8 nm (G line), 404.7 nm (H line) and 365.0 nm (I line) bands, and has good versatility. At the same time, the high-pressure mercury lamp has a high precise timing function, and can strictly control the exposure time in photolithography. However, there are some problems in actual use: due to the wide spectral range, it is necessary to filter out the unnecessary wavelengths with a filter during actual use, which will cause a large energy loss; the high-pressure mercury lamp must be preheated for several minutes before use to reach the required working temperature and make it in a stable working state, and a large amount of heat is generated during the working process, which affects the light emitting performance, so when using the mercury lamp, a shutter is generally added to control the exposure time, and a constant temperature device or cooling equipment is added, which increases the complexity, volume and cost of the system; the working life of the high-pressure mercury lamp is relatively short and has certain danger.

[0026] The ultraviolet laser light source generally includes a solid-state laser, a gas laser and a semiconductor laser. The semiconductor laser is also used in the DMD photolithography system due to its small size, light weight, low working voltage, strong monochromaticity and other advantages. However, the semiconductor laser is prone to speckle in the photolithography system due to its excellent coherence, which affects the projection imaging quality, so a speckle elimination device needs to be added in the system, which has a complex structure and high cost.

[0027] The UV LED light source is a PN junction diode made of semiconductor material, which converts electrical energy into light energy by relying on the recombination of electron-hole pairs when a forward current is injected. The UV LED has the advantages of simple structure, low cost, long service life and low power consumption, but there is a lack of corresponding implementation means in the prior art.

[0028] Based on this, the present application provides a light uniformity control method, a compound eye lens unit and a photolithography system. The scheme realizes the application of the LED UV light source in the DMD photolithography system as an exposure light source, without the need for complex beam expansion devices. The optical path is simple to set and the control process is efficient.

[0029] In order to facilitate the understanding of the present embodiment, first, a light uniformity control method disclosed in the present embodiment is introduced in detail. The method is used to control the spot divergence angle of the LED UV light source in the photolithography system, as shown in Figure 1 The method comprises: Step S101, based on the spot incident parameters corresponding to the LED UV light source, a compound eye lens unit corresponding to the LED UV light source is set in the photolithography system; wherein the compound eye lens unit comprises a double-row compound eye lens and a condenser lens.

[0030] Based on the spot incident parameters (core parameters including: light source initial divergence angle, light emitting surface size, UV wavelength (such as 365nm / 385nm, affecting lens material selection), light intensity distribution type (such as Lambertian distribution or Gaussian distribution)) of the LED UV light source, a compound eye lens unit (composed of a double-row compound eye lens and a condenser lens) is configured in the optical path of the photolithography system.

[0031] The double-row compound eye lens is composed of two rows of arrayed small lenses (the front row is a "field lens array" and the rear row is a "relay lens array"). The front row of lenses divides the divergent light beam of the LED light source into several sub-beams (each sub-beam corresponds to a local area of the light source), and the rear row of lenses corresponds to the front row one by one to collimate and correct the angle of each sub-beam. Compared with a single-row compound eye, the double-row structure can significantly improve the spot uniformity through "sub-beam independent control + superposition uniformization".

[0032] The condenser lens is located behind the double-row compound eye lens, and its function is to further converge the sub-beams output by the rear row of compound eyes and control the final form of the light beam on the imaging surface (such as the photolithography mask or the wafer surface). The aperture needs to cover the propagation range of all sub-beams.

[0033] Step S102, the first focal length corresponding to the double-row compound eye lens, the first position interval between the double-row compound eye lens and the condenser lens, and the second focal length of the condenser lens are obtained, and the first incident angle and the incident height corresponding to the LED UV light source are determined by using the spot incident parameters.

[0034] The step needs to determine the inherent parameters of the optical system and the incident parameters of the light source, to provide a basis for subsequent calculation. The inherent parameters mainly include: First focal length: refers to the focal length of a single lens in the rear row of fly's eye lens, reflecting the deflection ability of the sub-beam after the rear row of fly's eye, which can be determined by the distance between the double rows of fly's eye lens; First position distance: the center distance between the rear row of fly's eye lens and the condenser lens (installation parameter, which can be calibrated by laser interferometer, and the precision can be micron level, to avoid beam deviation caused by distance error); Second focal length: focal length of condenser lens (according to the distance requirement of imaging surface, it needs to match the working distance of the photoetching system).

[0035] The incident parameters mainly include: First incident angle: the angle between the light beam emitted by the LED light source and the optical axis (central axis of main light path) when it enters the front row of fly's eye lens; Incident height: the vertical distance between the point where the light beam enters the surface of the front row of fly's eye lens and the optical axis.

[0036] Step S103, based on the first incident angle, incident height, first focal length, first position distance and second focal length, the second incident angle and spot size corresponding to the imaging surface of the LED ultraviolet light source are calculated.

[0037] Based on the principle of geometric optical imaging, the second incident angle (the angle between the light beam and the optical axis on the imaging surface, which directly reflects the divergence angle) and the spot size (the diameter of the spot on the imaging surface) of the imaging surface (photoetching exposure surface) are calculated through the parameters in step S102.

[0038] Step S104, according to the second incident angle and the spot size, the corresponding spot divergence angle of the LED ultraviolet light source is controlled.

[0039] In the above process, the fly's eye lens subunit splits the incident light beam into multiple sub-channels, and the light beam of each channel can illuminate the entire target surface independently. When the light beams of multiple channels are superimposed, the non-uniformity of the single channel light beam can be compensated, thereby greatly enhancing the irradiation uniformity of the target surface.

[0040] Optionally, based on the spot incident parameters corresponding to the LED ultraviolet light source, the step S101 of setting the fly's eye lens unit corresponding to the LED ultraviolet light source in the photoetching system, as shown in Figure 2 includes: Step S201, according to the spot incident parameters, the incident spot size corresponding to the LED ultraviolet light source is determined, and based on the incident spot size, the size parameters corresponding to the fly's eye lens unit are determined.

[0041] Firstly, based on the spot incident parameters of the LED ultraviolet light source (including the initial divergence angle of the light source, the distance from the light source to the compound eye lens unit, and the equivalent diameter of the light-emitting surface), the incident spot size is calculated through geometric optics. Subsequently, the size parameters of the compound eye lens unit are determined according to the incident spot size, including the total array aperture of the double-row compound eye lens, the diameter of a single sub-lens, and the effective aperture of the condenser lens.

[0042] In step S202, the number of sub-lenses in the double-row compound eye lens for imaging is determined using the size parameters. Based on the number of sub-lenses and the second position interval between the double-row compound eye lenses, the first focal length corresponding to the double-row compound eye lens is determined.

[0043] Using the size parameters of step S201, the number of sub-lenses of the double-row compound eye lens is determined. The more the number, the finer the sub-beam segmentation, and the better the uniform light effect. Based on the number of sub-lenses, the first focal length is determined in combination with the second position interval between the double-row compound eye lenses.

[0044] In step S203, the position parameters between the condenser lens and the double-row compound eye lens are determined using the size parameters. Based on the position parameters, the first position interval between the double-row compound eye lens and the condenser lens is determined, and the second focal length between the condenser lens and the imaging surface of the LED ultraviolet light source is determined based on the position parameters.

[0045] According to the total length of the compound eye lens unit (the distance from the front row compound eye to the rear row compound eye) and the optical path layout of the lithography system (such as the total distance from the compound eye unit to the imaging surface), the position parameters of the condenser lens and the double-row compound eye lens are determined (the core is the relative position of the mounting reference surface of the condenser lens and the rear row compound eye). Based on the position parameters, the first position interval (the distance from the rear row compound eye to the condenser lens) is calculated. At the same time, the second focal length is inversely calculated in combination with the target spot size of the imaging surface.

[0046] In step S204, the double-row compound eye lens corresponding to the compound eye lens unit is set in the lithography system according to the first focal length and the first position interval, and the condenser lens corresponding to the compound eye lens unit is set in the lithography system according to the second focal length and the first position interval.

[0047] According to the first focal length of step S202 and the first position interval of step S203, the double-row compound eye lens is fixed in the optical path of the lithography system. The parallelism of the front and rear rows of compound eyes is adjusted through a precision guide rail, and the coaxiality of the sub-lens array and the light-emitting surface center of the light source is ensured. Subsequently, the condenser lens is installed according to the second focal length and the first position interval. The coincidence degree of the optical axis of the condenser lens and the optical axis of the compound eye unit is calibrated through a laser interferometer, and its position is fixed (positioning accuracy ≤1 μm, ensuring that the focal length and interval parameters are stable, and avoiding the influence of mechanical drift caused by temperature change on the spot quality).

[0048] Optionally, the first incidence angle and the incidence height corresponding to the LED ultraviolet light source are determined according to the spot incidence parameters, as shown in Figure 3 , which comprises the following steps: In step S301, the optical axis corresponding to the compound eye lens unit is determined based on the double-row compound eye lens and the condenser lens, and the first incidence angle corresponding to the LED ultraviolet light source is determined according to the angle between the spot incidence parameters and the optical axis.

[0049] The calibration of the optical axis of the compound eye lens unit establishes the optical axis based on the center line of the double-row compound eye lens. In actual operation, the laser collimator is used for calibration, a laser beam parallel to the theoretical optical axis is incident from the front row of the compound eye, and the position of the double-row compound eye lens is adjusted so that the laser beam passes through the double-row compound eye lens in sequence, so as to ensure that the deviation of the optical axis is less than a preset threshold. In the photoetching system, the optical axis needs to be perpendicular to the exposure table surface (the perpendicularity error is ≤0.001°), and the angle between the optical axis and the normal line of the table surface is measured by the autocollimator and adjusted.

[0050] The calculation process of the first incidence angle is that, for any outgoing light ray of the LED light source, the angle between the light ray and the optical axis is . In actual measurement, the cross-sectional image of the LED outgoing light beam is captured by using a high-speed camera (frame frequency ≥1000 fps), the direction of the light ray is fitted by using an image processing algorithm (such as Hough transformation), and the angle between the light ray and the optical axis is calculated.

[0051] In step S302, the incidence height corresponding to the LED ultraviolet light source is determined according to the positional relationship between the spot size and the optical axis.

[0052] The accurate measurement process of the spot size can use an ultraviolet-enhanced CCD camera to collect the spot image in front of the compound eye lens. The spot edge is extracted by image processing, the image is subjected to Gaussian filtering for noise reduction, and then a related threshold method is used to segment the spot area, and the diagonal length of the circumscribed rectangle of the area is calculated as the spot diameter. The incidence height refers to the vertical distance between the light ray at the edge of the spot and the optical axis. Generally, the incidence height is half of the spot diameter.

[0053] Optionally, the second incidence angle and the spot size corresponding to the imaging plane of the LED ultraviolet light source are calculated based on the first incidence angle, the incidence height, the first focal length, the first position spacing and the second focal length, as shown in Figure 4 , which comprises the following steps: In step S401, the diameter of the sub-lens in each row of the compound eye lens in the double-row compound eye lens is determined based on the number of sub-lenses. In step S402, the coordinate offset corresponding to the LED ultraviolet light source is calculated by using the diameter of the sub-lens and the number of sub-lenses. Step S403, calculating the second incidence angle and the spot size corresponding to the imaging plane of the LED ultraviolet light source based on the first incidence angle, the incidence height, the first focal length, the first position interval, the second focal length and the coordinate offset.

[0054] The focal length of the compound eye array is the first focal length The diameter of the sub-lens is After passing a distance D, it reaches the condenser lens, and the focal length of the condenser lens is the second focal length It images each sub-beam on the exposure plane, i.e. the back focal plane of the condenser lens, to form a uniform spot. In the light ray tracing mode: the incident light ray height is and the incidence angle is into the homogenization light path, and after passing through the double-row compound eye, an additional coordinate offset , is the number of sub-lenses incident to the compound eye (the sub-lens corresponding to the optical axis is channel 0), and then the image plane is tracked through the condenser lens.

[0055] The second incidence angle and the spot size are calculated by the following formula: ; Wherein, is the second incidence angle; is the coordinate value corresponding to the spot size in the imaging plane; is the second focal length; is the first position interval; is the coordinate offset; is the number of sub-lenses; is the diameter of the sub-lens; is the first focal length; is the first incidence angle; is the incidence height.

[0056] After arranging the above formula, the calculation results of the second incidence angle and the spot size are: .

[0057] It can be seen that the uniform spot size is only related to the focal length of the compound lens and the focal length of the condenser lens , and is independent of the distance between the compound lens and the condenser lens, while the divergence angle of the uniform spot is related to the distance. Optionally, the step S104 of controlling the spot divergence angle corresponding to the LED ultraviolet light source according to the second incidence angle and the spot size, as shown in Figure 5 , includes: Step S501, calculating the numerical aperture of the compound lens array using the sub-lens diameter and the first focal length, and determining the boundary condition corresponding to the spot incidence parameter based on the numerical aperture; Step S502, determining a first corresponding relationship between the incident height and the sub-lens diameter based on the boundary condition, and updating the second incident angle and the spot size based on the first corresponding relationship; Step S503 : controlling the light spot divergence angle to a minimum value according to the updated second incident angle and light spot size.

[0058] If the maximum incident angle to the first row of compound eye fibers is equal to the numerical aperture of the lens array , which is a necessary condition for the normal operation of the compound eye array. The maximum incident height of the light is equal to half the size of the compound eye sub-lens unit. Optionally, when the boundary condition is that the maximum value of the first incident angle is equal to the numerical aperture and the first corresponding relationship is that the incident height is equal to half the diameter of the sub-lens, the calculation results of the second incident angle and spot size are: ; Control the first position spacing based on the updated second incident angle and spot size Equal to the second focal length , so that the spot divergence angle reaches the minimum value, and the system meets the telecentric lighting conditions.

[0059] Based on the above formula, lighttools simulation is performed. In order to ensure the performance and accuracy of the lithography machine, the actual application requires that the parallel half-angle of the exposure light source is less than 2.5°, and the uniformity of the uniform light spot is stable at more than 90%. The central wavelength of the LED chip used in the simulation is 405nm, the spectral width is 10nm, the divergence angle is ±60°, and the luminous area is 3mm*3mm. The collimator part uses a combination of aspheric lens and double convex lens to improve the utilization rate of light energy and make the divergence angle of the collimated light incident on the double-row compound eye meet the requirements of the compound eye. The unit size of the compound eye is 1.5mm*1mm, the thickness is 10mm, the overall light-transmitting size is 15mm*15mm, and the number of sub-lenses is 10*15. The details are as follows:

[0060] It can be seen from the light uniformity control method in the above embodiment that this method realizes the application of LED ultraviolet light source in DMD lithography system as exposure light source, does not require complex beam expansion device, the light path is simple and easy to set up, and the control process is efficient.

[0061] The embodiment of the present invention further provides a fly-eye lens unit, such as Figure 6 As shown, the fly-eye lens unit includes at least a double row of fly-eye lenses and a focusing lens; wherein, the fly-eye lens unit adopts the uniform light control method mentioned in the above embodiment in the process of controlling the spot divergence angle of the LED ultraviolet light source in the lithography system.

[0062] The embodiment of the present application also provides a photoetching system, which is provided with an LED ultraviolet light source, and the LED ultraviolet light source adopts the compound eye lens unit mentioned in the above embodiment when eliminating speckle of an imaging surface; and the photoetching system adopts the light homogenization control method mentioned in the above embodiment in the process of using the compound eye lens unit to control the light homogenization.

[0063] Corresponding to the above light homogenization control method embodiment, the embodiment of the present application also provides a light homogenization control system for controlling a light spot divergence angle of an LED ultraviolet light source in a photoetching system, as shown in the formula (1), the light homogenization control system comprises: Figure 7 A first control module 710 is configured to set a compound eye lens unit corresponding to the LED ultraviolet light source in the photoetching system based on light spot incident parameters corresponding to the LED ultraviolet light source; wherein the compound eye lens unit comprises a double-row compound eye lens and a condenser lens; A second control module 720 is configured to acquire a first focal length corresponding to the double-row compound eye lens, a first position interval between the double-row compound eye lens and the condenser lens, and a second focal length of the condenser lens, and determine a first incident angle and an incident height corresponding to the LED ultraviolet light source by using the light spot incident parameters; A third control module 730 is configured to calculate a second incident angle and a light spot size corresponding to an imaging surface of the LED ultraviolet light source based on the first incident angle, the incident height, the first focal length, the first position interval and the second focal length; A fourth control module 740 is configured to control a light spot divergence angle corresponding to the LED ultraviolet light source according to the second incident angle and the light spot size.

[0064] It can be known from the above light homogenization control system that the system realizes the application of the LED ultraviolet light source in the DMD photoetching system as an exposure light source, does not need a complex beam expander, and has a simple light path, is easy to set and has an efficient control process.

[0065] The light homogenization control system provided by the embodiment of the present application has the same implementation principle and technical effects as the above light homogenization control method embodiment, and for brief description, the part not mentioned in the system embodiment can be referred to the corresponding content in the above light homogenization control method embodiment.

[0066] The embodiment also provides an electronic device, and a structural schematic diagram of the electronic device is as shown in the formula (2), the device comprises a processor 101 and a memory 102; wherein the memory 102 is configured to store one or more computer instructions, and the one or more computer instructions are executed by the processor to realize the steps of the above light homogenization control method. Figure 8

[0067] Figure 8 ​​The electronic device also includes a bus 103 and a communication interface 104, the processor 101, the communication interface 104 and the memory 102 are connected through the bus 103.

[0068] The memory 102 can include a high-speed random access memory (RAM), and can also include a non-volatile memory, such as at least one disk memory. The bus 103 can be an ISA bus, a PCI bus, or an EISA bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 8 Only one bidirectional arrow is used in the figure, but it does not mean that there is only one bus or one type of bus.

[0069] The communication interface 104 is used to connect with at least one user terminal and other network elements through a network interface, and send the encapsulated IPv4 packet or IPv4 packet to the user terminal through the network interface.

[0070] The processor 101 can be an integrated circuit chip with signal processing capability. In the implementation process, each step of the above method can be completed by integrated logic circuits or instructions in the form of software in the processor 101. The above processor 101 can be a general processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. Each method, step and logic block disclosed in the embodiment of the present disclosure can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in combination with the embodiment of the present disclosure can be directly embodied as a hardware code processor for execution, or a combination of hardware and software modules in the code processor for execution. The software module can be located in a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically erasable programmable memory, a register, or other mature storage media in the art. The storage medium is located in the memory 102, and the processor 101 reads the information in the memory 102, and combines the hardware to complete the steps of the method of the above embodiment.

[0071] The embodiment of the present application further provides a storage medium, which stores a computer program, and the computer program is run by a processor to execute the steps of the uniform light control method in the foregoing embodiment.

[0072] In several embodiments provided in the present application, it should be understood that the disclosed system, device, apparatus and method can be implemented by other manners. The system embodiments described above are only illustrative, for example, the division of the units is only a logical function division, and another division manner can be used in actual implementation, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some communication interfaces, devices or units, and can be electrical, mechanical or other forms.

[0073] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, can be located in one place, or can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0074] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit.

[0075] If the functions are realized in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer readable storage medium executable by a processor. Based on this understanding, the technical solutions of the present application or the part of the present application which is essential or contributes to the prior art can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various program code storage media.

[0076] Finally, it should be noted that the above-described embodiments are merely specific embodiments of the present application, which are used to illustrate the technical solutions of the present application, but not to limit the same. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that any person skilled in the art can still modify or easily think of changes to the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some of the technical features, within the technical scope disclosed by the present application. The modifications, changes or replacements do not cause the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A light uniformity control method, characterized in that: The method is used to control the light spot divergence angle of an LED ultraviolet light source in a photolithography system; the method comprises: A fly-eye lens unit corresponding to the LED ultraviolet light source is provided in the photolithography system based on the incident parameters of the light spot corresponding to the LED ultraviolet light source; wherein the fly-eye lens unit includes a double-row fly-eye lens and a focusing lens; Obtaining a first focal length corresponding to the double-row fly-eye lens, a first positional distance between the double-row fly-eye lens and the condenser lens, and a second focal length of the condenser lens, and determining a first incident angle and incident height corresponding to the LED ultraviolet light source using the light spot incident parameters; Calculating a second incident angle and a spot size corresponding to an imaging surface of the LED ultraviolet light source based on the first incident angle, the incident height, the first focal length, the first position spacing, and the second focal length; The light spot divergence angle corresponding to the LED ultraviolet light source is controlled according to the second incident angle and the light spot size.

2. The light uniformity control method according to claim 1, wherein: The step of setting a fly-eye lens unit corresponding to the LED ultraviolet light source in the photolithography system based on the light spot incident parameters corresponding to the LED ultraviolet light source includes: Determining an incident light spot size corresponding to the LED ultraviolet light source according to the light spot incident parameters, and determining a size parameter corresponding to the fly-eye lens unit based on the incident light spot size; Determining the number of sub-lenses for imaging in the double-row fly-eye lens using the size parameter, and determining the first focal length corresponding to the double-row fly-eye lens based on the number of sub-lenses and using the second position spacing between the double-row fly-eye lenses; Determining position parameters between the condensing lens and the double-row fly-eye lens using the size parameters, determining a first position spacing between the double-row fly-eye lens and the condensing lens based on the position parameters, and determining a second focal length between the condensing lens and the imaging plane of the LED ultraviolet light source based on the position parameters; The double-row fly-eye lens corresponding to the fly-eye lens unit is arranged in the photolithography system according to the first focal length and the first position spacing, and the focusing lens corresponding to the fly-eye lens unit is arranged in the photolithography system according to the second focal length and the first position spacing.

3. The light uniformity control method according to claim 2, wherein: Determining a first incident angle and an incident height corresponding to the LED ultraviolet light source using the light spot incident parameters includes: Determining the optical axis corresponding to the fly-eye lens unit based on the double-row fly-eye lens and the condenser lens, and determining the first incident angle corresponding to the LED ultraviolet light source using the angle between the light spot incident parameter and the optical axis; The incident height corresponding to the LED ultraviolet light source is determined according to the positional relationship between the incident light spot size and the optical axis.

4. The light uniformity control method according to claim 2, wherein: The step of calculating a second incident angle and a spot size corresponding to an imaging surface of the LED ultraviolet light source based on the first incident angle, the incident height, the first focal length, the first position spacing, and the second focal length includes: Determining the diameter of the sub-lenses in each row of the double-row fly-eye lenses based on the number of the sub-lenses; Calculating the coordinate offset corresponding to the LED ultraviolet light source using the sub-lens diameter and the number of sub-lenses; The second incident angle and the spot size corresponding to the imaging surface of the LED ultraviolet light source are calculated based on the first incident angle, the incident height, the first focal length, the first position spacing, the second focal length and the coordinate offset.

5. The light uniformity control method according to claim 4, characterized in that: The second incident angle and the spot size are calculated by the following formula: ； in, is the second incident angle; is the coordinate value corresponding to the spot size in the imaging plane; is the second focal length; is the first position spacing; is the coordinate offset; is the number of sub-lenses; is the diameter of the sub-lens; is the first focal length; is the first incident angle; is the incident height.

6. The light uniformity control method according to claim 5, characterized in that: The calculation results of the second incident angle and the spot size are: 。 7. The light uniformity control method according to claim 6, characterized in that: The step of controlling the light spot divergence angle corresponding to the LED ultraviolet light source according to the second incident angle and the light spot size includes: Calculating a numerical aperture of the fly-eye lens array using the sub-lens diameter and the first focal length, and determining boundary conditions corresponding to the light spot incident parameters based on the numerical aperture; Determining a first corresponding relationship between the incident height and the sub-lens diameter based on the boundary condition, and updating the second incident angle and the spot size based on the first corresponding relationship; The light spot divergence angle is controlled to a minimum value according to the updated second incident angle and the light spot size.

8. The light uniformity control method according to claim 7, characterized in that: When the boundary condition is that the maximum value of the first incident angle is equal to the numerical aperture and the first corresponding relationship is that the incident height is equal to half the diameter of the sub-lens, the calculation result of the second incident angle and the spot size is: ； Controlling the first position spacing according to the updated second incident angle and the spot size Equal to the second focal length , so that the light spot divergence angle reaches a minimum value.

9. A compound eye lens unit, characterized in that: The fly-eye lens unit comprises at least a double row of fly-eye lenses and a focusing lens; wherein, the fly-eye lens unit adopts the light uniforming control method according to any one of claims 1 to 8 in the process of controlling the light spot divergence angle of the LED ultraviolet light source in the lithography system.

10. A photolithography system, characterized in that: The photolithography system is provided with an LED ultraviolet light source, and the LED ultraviolet light source adopts the fly-eye lens unit mentioned in claim 9 when eliminating speckles on the imaging surface; In the process of performing light homogenization control on the speckle using the fly-eye lens unit, the light homogenization control method according to any one of claims 1 to 8 is adopted.

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