Dynamic matrix mirror capable of converting laser into same frequency different phase non-coherent laser

Abstract

The utility model relates to a kind of dynamic matrix reflector capable of converting laser into same frequency different phase incoherent laser, wherein ceramic substrate lower side is equipped with electrical connection block, upper side is equipped with electrical connection disc, and electrical connection block lower side is connected with corresponding output control unit, upper side is electrically connected with corresponding electrical connection disc through corresponding electrical connection hole, each electrical connection disc upper side is equipped with piezoelectric ceramic piece, and each piezoelectric ceramic piece is equipped in ceramic frame, ceramic frame and each piezoelectric ceramic piece upper side are equipped with common electrode layer, common electrode layer upper side is equipped with reflector layer, ceramic substrate edge is equipped with common electrode pin and common electrode layer connection, lower electrode metal layer of piezoelectric ceramic piece is connected with corresponding electrical connection disc, and upper electrode metal layer is connected with common electrode layer.The utility model realizes the purpose that reflector layer does thousands of irregular jitter within a exposure time by piezoelectric ceramic piece power on, and makes laser convert into same frequency different phase incoherent laser.

Description

Technical Field

[0001] This utility model relates to the field of lithography machines, specifically a dynamic matrix reflector that can convert laser light into incoherent laser light of the same frequency but different phases. Background Technology

[0002] In existing technologies, the EUV lithography machine from the Dutch brand ASML uses a deep ultraviolet light source with a wavelength of 13.5nm. It uses a high-power carbon dioxide laser to pulse and focus onto continuously falling liquid tin beads, instantly vaporizing them and exciting them into plasma light emission. However, this light source is a broad-spectrum light, not a laser. It needs to undergo complex filtering to obtain a narrowband light centered at 13.5nm and containing many frequency components. Since the refractive index of light in the same transparent material is related to the wavelength, ASML uses a mirror imaging system in the process of optically miniaturizing integrated circuit templates. This is because the angle of incidence and the angle of reflection on the mirror are equal with the angle bisector of the incident point normal, and are independent of the wavelength of the light. However, these mirror groups cannot be coaxial, and their imaging structure is complex. Therefore, a huge structural space is required, and a frame with very high strength and rigidity is needed to maintain the stability of the projection relationship of the mirror system.

[0003] If EUV lithography machines could directly use 13.5nm lasers, it would simplify miniaturized optical systems. For example, Tsinghua University is developing the SSMB-EUV light source, which can provide a 13.5nm laser source for high-precision lithography machines. However, many of the mask images corresponding to the chip are monochrome images, either black or white. In the black areas, the mask completely blocks photons, so even lasers cannot create interference speckle in the dark areas of the miniature image. In the bright areas of the miniature image, light waves of the same wavelength but different paths will interfere, resulting in dark spots with fixed positions. These dark spots will affect the lithography quality and may even lead to defective products. Although there are relatively mature dedispersion processes in the 350-700nm (visible light) range, the method for dedispersion in the 13.5nm center wavelength range is not yet mastered.

[0004] Patent application number 202110524685.X discloses a reflector, a photolithography apparatus, and a control method thereof. This apparatus utilizes a rotating disk as a reflector, and the reflective surface of the reflector includes multiple micro-reflective surfaces. Specifically, the rotating disk is divided into several sectors, and each sector is concentrically divided radially into several sub-mirror areas (micro-reflective surfaces), each with a different height. When the apparatus is in use, the light emitted from the light source is reflected by the rotating reflector, causing the phase of the light to continuously change. This results in a constantly changing interference pattern formed by the coherent light after passing through the illumination system in the illumination area of ​​the photomask, and homogenizes the cumulative light intensity of the photomask's illumination field of view during the exposure time, thus achieving uniform illumination. In other words, when incident light shines on the rotating group of reflective sub-mirrors, although the direction of the reflected light remains unchanged, its phase undergoes a pseudo-random change as the group of reflective sub-mirrors rotates, thereby solving the speckle problem. However, because the number of sub-mirrors on the rotating disk is limited, the resulting number can only be a pseudo-random number with a small number of digits. Furthermore, the relationship between the mirror rotation period and the exposure time must be considered. If the exposure time is much longer than the mirror rotation period, the speckle movement trajectory will exhibit periodic repetition, resulting in the speckle still affecting the exposure. If the exposure time is roughly equal to the rotation period, then a dozen or so sub-mirrors will form a dozen or so slowly moving speckle areas, similarly affecting the exposure. Additionally, although the precision of mechanical measurements can currently reach the nanometer level, the level of machining generally cannot reach this level. Moreover, if the thickness difference between different sub-mirrors is exactly an integer period of optical path difference, then it is equivalent to not achieving an optical path difference, and this possibility still exists.

[0005] Patent application number 202180036748.5 discloses a mirror specifically for microlithography, comprising a mirror substrate, a reflective layer system, and at least one continuous piezoelectric layer disposed between the mirror substrate and the reflective layer system. The piezoelectric layer is capable of being applied to generate a locally deformable electric field via a first electrode arrangement on the side of the piezoelectric layer facing the reflective layer system and a second electrode arrangement on the side of the piezoelectric layer facing the mirror substrate. At least one of the electrode arrangements is provided with a dielectric layer for setting at least a locally continuous potential distribution along the respective electrode arrangement. In use, the device applies a voltage to the electrodes through the formed electric field, causing deflection of the piezoelectric layer. This compensates for optical aberrations, such as those caused by thermal deformation when EUV radiation is incident on an optically effective surface. It can actuate the mirror, but the device is not intended to eliminate speckle. Utility Model Content

[0006] The purpose of this invention is to provide a dynamic matrix reflector that can convert laser light into incoherent laser light of the same frequency but different phases. It utilizes the extension and retraction adjustment of each piezoelectric ceramic sheet after it is energized, thereby enabling the reflector layer to undergo thousands of irregular jitters within a single exposure time. This also ensures that the interference spot moves irregularly thousands of times to guarantee sufficient uniform light and eliminate the spot, thereby converting the laser light into incoherent laser light of the same frequency but different phases.

[0007] The objective of this utility model is achieved through the following technical solution:

[0008] A dynamic matrix reflector capable of converting laser light into incoherent laser light of the same frequency but different phase includes a ceramic substrate and a control system. The ceramic substrate has multiple electrical connection blocks on its lower side and multiple electrical connection disks on its upper side. The control system includes multiple output control units. The ceramic substrate has multiple electrical connection holes, and each electrical connection block is connected to its corresponding output control unit on its lower side and to its corresponding electrical connection disk on its upper side via the corresponding electrical connection hole. Each electrical connection disk has a piezoelectric ceramic sheet on its upper side. The upper edge of the ceramic substrate has a ceramic frame, and each piezoelectric ceramic sheet is disposed within the ceramic frame. A common electrode layer is provided on the ceramic frame and each piezoelectric ceramic sheet. A reflector layer is provided on the upper side of the common electrode layer. A common electrode pin is provided on the edge of the ceramic substrate, with its upper end connected to the common electrode layer and its lower end electrically connected to a power ground module on the control system. Each piezoelectric ceramic sheet includes a lower electrode metal layer, a piezoelectric ceramic layer, and an upper electrode metal layer arranged sequentially from bottom to top. The lower electrode metal layer is connected to the corresponding electrical connection disk, and the upper electrode metal layer is connected to the common electrode layer.

[0009] The actuation distance of the piezoelectric ceramic layer of the piezoelectric ceramic sheet after being energized is within the range of ±6.75nm.

[0010] The electrical connection plate includes multiple square blocks arranged in a square matrix, and adjacent blocks are connected by straight connecting strips. The diagonal ends of the electrical connection plate are connected by diagonal connecting strips, and electrical connection holes are provided at the intersection of two diagonal connecting strips. The lower electrode metal layer on the underside of the piezoelectric ceramic sheet is welded to the corresponding block of the electrical connection plate.

[0011] Each side edge of the ceramic substrate is provided with a substrate pin groove, and each side edge of the ceramic frame is provided with a frame pin groove. Each frame pin groove and each substrate pin groove are connected in a one-to-one correspondence to form multiple pin mounting grooves. The common electrode pin is embedded and fixed in the corresponding pin mounting groove.

[0012] The lower end of the common electrode pin is provided with a right-angle bending plate, and the right-angle bending plate is fastened to the bottom surface of the ceramic substrate to form a pin pad. The thickness of the pin pad is the same as the thickness of the electrical connection block.

[0013] The control system includes a data storage control unit, a frequency divider, and multiple output control units. The data storage control unit internally includes a matrix control metadata page, a page address counter, and a matrix control metadata address counter. One end of the page address counter is connected to the frequency divider via a clock data input line, and the other end is connected to one end of the matrix control metadata address counter via a first connection line. The other end of the matrix control metadata address counter is connected to the stop port on the frequency divider via a second connection line. The output control unit includes a buffer memory, a latch, and a D / A converter connected in sequence. An output control bus for outputting data from each matrix control metadata page is located outside the data storage control unit. The output control bus includes multiple control branches, each connected to the buffer memory in the corresponding output control unit. A signal bus is led out from the first connection line, including multiple signal branches, each connected to the latch in the corresponding output control unit. The D / A converter is connected to the corresponding piezoelectric ceramic plate.

[0014] The page address of the matrix control metadata page is counted by the page address counter, and the carry-to-zero number of the page address counter is equal to the number of output control units, both being A. The matrix control metadata page is counted by the matrix control metadata address counter.

[0015] A square beam homogenizer is provided on the light incident side of the reflective mirror layer.

[0016] The square beam homogenizer includes a fixed frame and a square tube reflector disposed within the fixed frame. The input port edge of the square tube reflector is provided with an input port reinforcement frame. One side of the input port reinforcement frame in the left-right direction is connected to a first mounting plate disposed on the corresponding inner wall of the fixed frame via a first piezoelectric ceramic column, and the other side is connected to the corresponding inner wall of the fixed frame via a first spring. One side of the input port reinforcement frame in the up-down direction is connected to a second mounting plate disposed on the corresponding inner wall of the fixed frame via a second piezoelectric ceramic column, and the other side is connected to the corresponding inner wall of the fixed frame via a second spring.

[0017] The output port edge of the square tube reflector is provided with an output port reinforcement frame, and each side of the output port reinforcement frame is connected to the inner wall of the corresponding side of the fixed frame through a corresponding reinforcement frame mounting piece.

[0018] The advantages and positive effects of this utility model are as follows:

[0019] 1. This invention effectively perturbs the phase of the reflected light from the laser beam incident on the reflector layer, thereby eliminating the interference speckle generated by the projection system using it as the light source, and thus converting the laser into an incoherent laser with the same frequency but different phase. In this invention, the reflector layer is adjusted by extending and retracting each piezoelectric ceramic sheet after being energized, so that the reflector layer can perform thousands of irregular jitters within a single exposure time, which means that the interference spot moves irregularly thousands of times, thereby ensuring sufficient uniform light to eliminate the spot.

[0020] 2. The device of this utility model has a compact overall structure, and all components of this utility model are processed using mature technology, which can fully guarantee the processing accuracy. In this utility model, the piezoelectric ceramic sheets are energized and stretched to drive the corresponding sub-mirror areas on the reflector layer to rise or fall to achieve the purpose of eliminating speckle, without requiring changes in the thickness of the sub-mirror areas. Therefore, the thickness of each sub-mirror area of ​​the reflector layer of this utility model is the same, and it is also convenient to ensure the consistency of each sub-mirror area during processing.

[0021] 3. The actuation distance range of the piezoelectric ceramic sheet of this utility model is ±6.75nm, which is within the range of ±1 / 2 wavelength (13.5nm) of light. It will not waste energy because deformation of an integer multiple of wavelength has no phase change significance. Moreover, in addition to wasting energy, this energy will also be converted into heat, affecting the service life of the reflector. In addition, relative to the overall thickness of the reflector layer + common electrode layer, the vertical jitter misalignment range of the adjacent sub-mirror area of ​​the reflector layer is always less than or equal to one wavelength (13.5nm). Its maximum deformation is less than 1 / 400 of the overall thickness of the reflector layer + common electrode layer. Therefore, it will not cause fatigue fracture of the common electrode metal layer that serves as the mirror substrate.

[0022] 4. The switching cycle of the piezoelectric ceramic sheet controlled by the control system of this utility model is about 1 / 3 of the resonant cycle of the piezoelectric ceramic sheet. This ensures that the sub-mirror area array of the reflective mirror layer is in a dynamic adjustment process throughout the entire exposure time. That is, the speckle of each laser projection is constantly moving and does not pause briefly at any point, thereby ensuring uniform light effect.

[0023] 5. Compared with the prior art, the fact that the interference spot does not follow the same path each time is determined by the matrix control metadata formed by the control system, which is unrelated to the manufacturing process of the device components, and therefore will not be affected by the manufacturing precision of the components.

[0024] 6. Considering that imaging systems often include square beam homogenizers, this invention also improves upon the square beam homogenizer. The first and second piezoelectric ceramic pillars at the input end of the square beam homogenizer expand and contract under applied voltage, causing irregular jittering of the input port of the square tube reflector along the left-right and up-down directions. This jittering alters the incident point of the incident light on the four mirrors inside the square tube reflector, resulting in a slight change in the optical path length through the square beam homogenizer. The light beam then illuminates the continuously jittering mirror layer, further enhancing the speckle reduction effect. Attached Figure Description

[0025] Figure 1 This is a cross-sectional view of the structure of this utility model.

[0026] Figure 2 for Figure 1 A schematic diagram of the ceramic substrate structure.

[0027] Figure 3 for Figure 2 A schematic diagram of the structure after an electrical connection block is installed on the bottom surface of the ceramic substrate.

[0028] Figure 4 for Figure 2 A schematic diagram of the structure after the electrical connection plate is installed on the front of the ceramic substrate.

[0029] Figure 5 for Figure 4 Enlarged view of point A in the image.

[0030] Figure 6 for Figure 4 A schematic diagram of the structure of the ceramic substrate after the piezoelectric ceramic sheet is placed on the electrical connection plate.

[0031] Figure 7 for Figure 6 A schematic diagram of the piezoelectric ceramic sheet structure in the image.

[0032] Figure 8 for Figure 6 A schematic diagram of the structure of the ceramic substrate after a ceramic frame is set on the outside of the piezoelectric ceramic sheet.

[0033] Figure 9 for Figure 8 A schematic diagram of the ceramic frame structure.

[0034] Figure 10 for Figure 8 A schematic diagram of the electrode pin structure in the diagram.

[0035] Figure 11 for Figure 1A schematic diagram of the bottom structure of this utility model.

[0036] Figure 12 for Figure 1 A schematic diagram of the overall appearance of this utility model.

[0037] Figure 13 This is a schematic diagram of the control flow of one embodiment of the present invention.

[0038] Figure 14 for Figure 13 A schematic diagram of the control system used in the Chinese embodiment.

[0039] Figure 15 This is a schematic diagram of the structure of a square beam homogenizer used in another embodiment of the present invention.

[0040] Figure 16 for Figure 15 A schematic diagram of the square beam homogenizer from another angle.

[0041] Wherein, 1 is a ceramic substrate, 101 is a substrate pin slot, 102 is an electrical connection hole, 103 is a square area, 2 is an electrical connection block, 3 is an electrical connection disk, 301 is a square, 302 is a straight connecting strip, 303 is a diagonal connecting strip, 4 is a piezoelectric ceramic sheet, 401 is a piezoelectric ceramic layer, 402 is an upper electrode metal layer, 403 is a lower electrode metal layer, 5 is a ceramic frame, 501 is a frame pin slot, 6 is a common electrode pin, 601 is a pin pad, 7 is a reflector layer, 8 is a control system, 801 is a data storage control unit, 802 is a frequency divider, 803 is a buffer memory, 804 is a latch, 80 5 is a D / A converter, 9 is a square beam homogenizer, 901 is a square tube reflector, 902 is a fixing frame, 903 is an input port, 9031 is an input port reinforcing frame, 904 is a first piezoelectric ceramic cylinder, 9041 is a first mounting plate, 9042 is a first positive lead, 9043 is a first negative lead, 905 is a second piezoelectric ceramic cylinder, 9051 is a second mounting plate, 9052 is a second positive lead, 9053 is a second negative lead, 906 is a second spring, 907 is a first spring, 908 is an output port, 9081 is an output port reinforcing frame, 9082 is a reinforcing frame mounting plate, and 10 is a common electrode layer. Detailed Implementation

[0042] The present invention will now be described in further detail with reference to the accompanying drawings.

[0043] like Figures 1-16 As shown, this utility model includes a ceramic substrate 1 and a control system 8, wherein... Figure 3 As shown, the ceramic substrate 1 has multiple independent electrical connection blocks 2 on its lower side, such as... Figures 4-5As shown, the upper side of the ceramic substrate 1 is provided with multiple independent electrical connection disks 3, such as... Figure 2 As shown, the ceramic substrate 1 is provided with a plurality of electrical connection holes 102, and each electrical connection block 2 is electrically connected to the corresponding electrical connection plate 3 through the corresponding electrical connection hole 102, such as... Figure 1 and Figure 6 As shown, each electrical connection plate 3 has a piezoelectric ceramic sheet 4 on its upper side, such as... Figure 1 and Figure 8 As shown, a ceramic frame 5 is provided along the upper edge of the ceramic substrate 1, and each piezoelectric ceramic sheet 4 is disposed within the ceramic frame 5, as shown. Figure 1 and Figure 14 As shown, a common electrode layer 10 is provided on the upper side of the ceramic frame 5 and each piezoelectric ceramic sheet 4, and a reflective mirror layer 7 is provided on the upper side of the common electrode layer 10. Additionally, as shown... Figure 14 As shown, the control system 8 includes multiple output control units, and each electrical connection block 2 on the lower side of the ceramic substrate 1 is connected to its corresponding output control unit, such as... Figure 8 and Figures 10-11 As shown, the ceramic substrate 1 has a common electrode pin 6 on its edge, and the upper end of the common electrode pin 6 is connected to the common electrode layer 10, and the lower end is electrically connected to the power ground module to achieve grounding. Figure 7 As shown, the piezoelectric ceramic sheet 4 includes a lower electrode metal layer 403, a piezoelectric ceramic layer 401, and an upper electrode metal layer 402 arranged sequentially from bottom to top. The lower electrode metal layer 403 is connected to the electrical connection disk 3 corresponding to the upper side of the ceramic substrate 1, and the upper electrode metal layer 402 is connected to the common electrode layer 10. In operation, the output control unit in the control system 8 is electrically connected to the lower electrode metal layer 403 of the corresponding piezoelectric ceramic sheet 4 via the corresponding electrical connection block 2, electrical connection hole 102, and electrical connection disk 3. Simultaneously, the power ground module on the control system 8 is electrically connected to the upper electrode metal layer 402 of the piezoelectric ceramic sheet 4 via the common electrode pin 6 and common electrode layer 10. This allows the control system 8 to apply voltage to the piezoelectric ceramic layer 401 to change its length. The ability of piezoelectric ceramics to stretch and shrink under power is a well-known technique in the field; for example, see patent CN115542533B. This patent applies a periodic, high-frequency phase modulation electrical signal to the phase-modulated piezoelectric ceramic, causing it to deform accordingly, thereby causing the optical fiber to stretch or shorten synchronously and periodically. However, this invention utilizes the stretching and shrinking adjustment of each piezoelectric ceramic sheet 4 to adjust the reflector layer 7, enabling the reflector layer 7 to undergo thousands of irregular jitters within a single exposure time. This means the interference spot moves irregularly thousands of times, ensuring sufficient light uniformity to eliminate light spots.

[0044] like Figure 7 As shown, the thickness of the piezoelectric ceramic layer 401 of the piezoelectric ceramic sheet 4 should be more than 1000 times its own actuation distance. For example, in this embodiment, the actuation distance range required for the piezoelectric ceramic layer 401 to drive the corresponding part of the reflector layer 7 to move is between ±6.75nm. The actual required thickness is only about 7μm, which is too low. Therefore, in this embodiment, the thickness of the piezoelectric ceramic layer 401 is 0.25mm, and then the required actuation distance is achieved by controlling the output voltage through the control system 8.

[0045] like Figure 2 As shown, in this embodiment, when processing the electrical connection hole 102 on the ceramic substrate 1, the ceramic substrate 1 is first divided into m×n square regions 103 in a rectangular array according to the size of the piezoelectric ceramic sheet 4, where each square region 103 corresponds to one piezoelectric ceramic sheet 4. Then, the electrical connection hole 102 is processed at the center of each square region 103. In this embodiment, the ceramic substrate 1 is divided into 6×8 square regions 103, each square region 103 has a size of 7×7mm, and the diameter of the electrical connection hole 102 is 80~200μm. Additionally, as... Figure 2 As shown, this utility model also requires the processing of substrate pin slots 101 on each side edge of the ceramic substrate 1 for mounting the common electrode pins 6. In order to ensure reliable electrical connection between the common electrode layer 10 and the power ground module provided on the control system 8, this utility model needs to reserve multiple substrate pin slots 101 for mounting multiple common electrode pins 6. In this embodiment, 20 substrate pin slots 101 are reserved.

[0046] like Figures 3-5 As shown, after processing the electrical connection holes 102 and the substrate pin slots 101, the upper and lower surfaces of the ceramic substrate 1 are plated with a solderable metal plating layer (the thickness of the metal plating layer in this embodiment is 5 micrometers), and metal is also injected into each electrical connection hole 102 to achieve electrical connection between the upper and lower metal plating layers. Then, this invention uses laser lithography to remove the excess metal plating layer on the bottom surface of the ceramic substrate 1 as shown. Figure 3 As shown, multiple independent electrical connection blocks 2 are formed to remove excess metal plating from the top surface of the ceramic substrate 1 as follows: Figures 4-5 As shown, multiple independent electrical connection panels 3 are formed, such as Figure 5As shown, in this embodiment, the electrical connection disk 3 includes multiple square blocks 301 arranged in a square matrix, and adjacent blocks 301 are connected by straight connecting strips 302. The diagonal ends of the electrical connection disk 3 are connected by diagonal connecting strips 303, and an electrical connection hole 102 is provided at the intersection of two diagonal connecting strips 303. In this embodiment, the gap between two adjacent electrical connection disks 3 is 5-8 μm. The present invention forms electrical connection disks 3 and electrical connection blocks 2 on the upper and lower surfaces of the ceramic substrate 1 to solve the problem of compatibility between solder and ceramic expansion. In addition, when installing the piezoelectric ceramic sheet 4, this invention first uses PCB technology to cover the straight connecting strips 302 and diagonal connecting strips 303 of the electrical connection plate 3 with solder resist, exposing only the square 301 portion. Then, solder paste is printed onto the corresponding square 301 of the electrical connection plate 3 using screen printing. Next, the lower electrode metal layer 403 on the underside of the piezoelectric ceramic sheet 4 is soldered onto the exposed square 301 of the corresponding electrical connection plate 3 using reflow soldering. The piezoelectric ceramic sheet 4 has metal films deposited on both its upper and lower surfaces to form upper and lower electrode metal layers. Furthermore, this invention utilizes the uniformly distributed solder-coated squares 301 to ensure that the piezoelectric ceramic sheet 4 is uniformly stressed and soldered onto the corresponding electrical connection plate 3. Additionally, when soldering the piezoelectric ceramic sheet 4, this invention can, according to actual needs, use an auxiliary alignment fixture to align all the neatly arranged piezoelectric ceramic sheets 4 (6×8 in this embodiment) with the respective electrical connection plates 3 on the ceramic substrate 1 at once, and then complete the soldering using reflow soldering. In this embodiment, the gap between adjacent piezoelectric ceramic sheets 4 is 3 to 8 μm, with a preferred value of 4 μm.

[0047] After the piezoelectric ceramic sheet 4 is installed, as follows Figure 8 As shown, in this invention, a ceramic frame 5 is installed on the outside of the matrix formed by piezoelectric ceramic sheets 4. In this embodiment, the ceramic frame 5 is bonded to the ceramic substrate 1 with quick-drying adhesive. The ceramic frame 5 serves both to protect the matrix of piezoelectric ceramic sheets 4 and to act as a support frame for the overall reflector. The upper surface of the ceramic frame 5 and the surfaces of each piezoelectric ceramic sheet 4 must be flush. In addition to the substrate pin groove 101 on the edge of the ceramic substrate 1, as... Figure 9 As shown, each side of the ceramic frame 5 is also provided with a frame pin groove 501, and each frame pin groove 501 is connected to each substrate pin groove 101 in a one-to-one correspondence to form multiple pin mounting grooves, and then as shown... Figure 8 and Figure 10 As shown, the common electrode pins 6 are respectively fixed in the corresponding pin mounting slots using adhesive. The upper ends of the common electrode pins 6 are located in the corresponding frame pin slots 501 to achieve electrical communication with the subsequently formed common electrode layer 10. Figure 9 As shown, the lower end of the common electrode pin 6 is provided with a right-angle bent plate, and as... Figure 11As shown, the right-angle bent plate is fastened to the bottom surface of the ceramic substrate 1 to form a pin pad 601. The thickness of the pin pad 601 is the same as the thickness of the electrical connection block 2, and it is subsequently welded to the corresponding power ground terminal block on the PCB board of the control system 8 to achieve electrical connection.

[0048] After the ceramic frame 5 is installed, a 4-6 μm thick chemically stable and highly smooth metal film is magnetron sputtered onto each piezoelectric ceramic sheet 4 and the ceramic frame 5 to form the common electrode layer 10. The common electrode layer 10 needs to cover all piezoelectric ceramic sheets 4 and the ceramic frame 5. Then, an optically reflective layer (optical reflective coating for 13.5 nm center wavelength light) that is highly reflective to EUV laser is deposited on the common electrode layer 10 to form the mirror layer 7. The mirror layer 7 can be divided into multiple sub-mirror regions according to the matrix distribution of the piezoelectric ceramic sheets 4. Each sub-mirror region corresponds to one piezoelectric ceramic sheet 4. Since the actuation distance of each sub-mirror region is controlled within ±6.75 nm, it falls completely within the safe elastic strain range of the mirror substrate metal film (i.e., the common electrode layer 10). Therefore, it will not cause fatigue fracture of the metal film (common electrode layer 10) of adjacent sub-mirror regions. After the reflector layer 7 is processed, the present invention can use a polishing machine to polish the reflector layer 7 according to actual needs to further improve the reflection efficiency of the mirror surface.

[0049] After all the above components are assembled, the present invention finally uses a reflow soldering process to solder the electrical connection block 2 on the lower side of the ceramic substrate 1 and the pin pad 601 at the lower end of the common electrode pin 6 onto the PCB board of the control system 8, and the electrical connection block 2 and the pin pad 601 are respectively soldered and fixed to the corresponding end plate on the PCB board of the control system 8.

[0050] The working principle of this utility model is as follows:

[0051] During operation, the control voltage on each piezoelectric ceramic sheet 4 is controlled by the control system 8, wherein, for example... Figure 14As shown, the control system 8 includes multiple output control units, and each output control unit includes a D / A converter 805 for controlling voltage conversion. In this embodiment, when the voltage is controlled to be applied in the forward direction by the D / A converter 805, the corresponding piezoelectric ceramic sheet 4 extends and drives the corresponding sub-mirror region on the reflective mirror layer 7 to rise. When the voltage is controlled to be applied in the reverse direction by the D / A converter 805, the corresponding piezoelectric ceramic sheet 4 shortens and drives the corresponding sub-mirror region on the reflective mirror layer 7 to fall. The rise and fall amplitude of each sub-mirror region is controlled within ±6.75nm. This invention utilizes the extension and retraction of each piezoelectric ceramic sheet 4 to adjust the reflective mirror layer 7, thereby enabling the reflective mirror layer 7 to undergo thousands of irregular jitters within a single exposure time, which means that the interference spot moves irregularly thousands of times to ensure sufficient uniform light and eliminate the spot.

[0052] like Figures 1-14 As shown, in this embodiment, the piezoelectric ceramic sheet matrix used to control speckle reduction includes 6×8 piezoelectric ceramic sheets 4, and the elongation and shortening states of each piezoelectric ceramic sheet 4 can be represented by 0 and 1 numbers, thus forming 6×8 pseudo-random data matrices each time. These 6×8 pseudo-random data form a mirror state, therefore these 48 ordered data are also called matrix control elements. During the 100ms of photolithography exposure, this embodiment prepares a total of 2048 matrix control elements, and requires that the data in any two matrix control elements M and N among these 2048 matrix control elements must satisfy M... ij ≠N ij (i ranges from 0 to 5, j ranges from 0 to 7), meaning that no data in M ​​and N is equal. The total control period of these matrix control elements is approximately 1 / 3 of the resonant period of the piezoelectric ceramic sheet 4. This ensures that the sub-mirror region array of the reflector layer 7 is in a dynamic adjustment process throughout the entire exposure time, meaning that the speckle of each laser projection is in motion to improve the uniform light effect.

[0053] like Figure 14 As shown, the control system 8 of this utility model includes a data storage control unit 801, and all matrix control elements generated by the system that meet the requirements are stored in the data storage control unit 801, such as... Figure 13 As shown, the specific steps involved in generating compliant matrix control metadata are as follows:

[0054] Step 1.1: The system generates a set of s×n pseudo-random data matrices as a matrix control element based on the elongation and shortening of s×n (i.e., 6×8 in this embodiment) piezoelectric ceramic sheets 4.

[0055] Step 1.2: Determine if the matrix control element is the first one. If it is, store it in the data storage control unit 801. Otherwise, proceed to step 1.3.

[0056] Step 1.3: Compare the values ​​of the i-th row and j-th column of the newly generated matrix control element with the values ​​of the i-th row and j-th column of all matrix control elements already stored in the data storage control unit 801, where i = 0, 1...s and j = 0, 1...n. If they are equal, the matrix control element is not stored in the data storage control unit 801; if they are not equal, the matrix control element is stored in the data storage control unit 801.

[0057] Step 1.4: Once the number of matrix control elements stored in the data storage control unit 801 meets the requirement (1000 sets in this embodiment), the system stops generating new matrix control elements.

[0058] like Figure 14 As shown, in this embodiment, the data storage control unit 801 of the control system 8 includes 1024 matrix control metadata pages, each page containing 48 signed 12-bit data (i.e., 48 internal addresses). The data storage control unit 801 also includes a 48-to-1 internal address counter and a 1024-to-1 matrix control metadata address counter. One end of the internal address counter is connected to the frequency divider 802 via a clock data input line for timing control, and the other end is connected to the matrix control metadata address counter via a first connection line. The matrix control metadata address counter is connected to the stop port on the frequency divider 802 via a second connection line. In this embodiment, the frequency divider 802 uses a 40MHz crystal oscillator as the clock oscillator, and after frequency division, generates a main clock signal of approximately 480,000Hz.

[0059] like Figure 14 As shown, each output control unit of the control system 8 controls the extension and retraction of the corresponding piezoelectric ceramic sheet 4. In this embodiment, the output control unit includes a buffer memory 803, a latch 804, and a D / A converter 805 connected in sequence. The output control bus 8011 of the data storage control unit 801 includes several control branches, and each control branch is connected to the buffer memory 803 in the corresponding output control unit. The 48 address decoding lines within a page of the data storage control unit 801 are sequentially connected to the data input terminals of the 48 buffer memories 803. In addition, the first connection line between the page address counter and the matrix control element address counter leads to a signal bus 8012. The signal bus 8012 includes multiple signal branches, and each signal branch is connected to the latch 804 in the corresponding output control unit. The D / A converter 805 in each output control unit is connected to the corresponding piezoelectric ceramic sheet 4.

[0060] The data storage control unit 801, frequency divider 802, buffer memory 803, latch 804 and D / A converter 805 are all technologies known in the art.

[0061] The timing sequence in this embodiment is as follows: First, select a ceramic material with a response frequency of 10kHz. After power-on, the clock oscillator on the frequency divider 802 starts oscillating, but the frequency divider 802 controlling the clock cycle does not work initially. Only after the exposure signal is triggered does the frequency divider 802 start working. At the same time, the exposure signal also clears the 48-to-1 page address counter and the 1024-to-1 matrix control metadata address counter, and the zero address enable signal is sent to buffer 0 so that it can store data. Other buffers do not have the corresponding address enable signal and cannot store data. At this time, the main clock cycle starts, and the rising edge of the first pulse of the main clock signal causes the system to store the data in the 0th page of the 0th matrix control metadata page (out of a total of 1024 matrix control metadata pages). The data for each address (48 addresses per matrix control metadata page) is input into buffer 0. The falling edge of the first clock pulse increments the page address counter by 1, and simultaneously sends the address enable signal to buffer 1, allowing storage. Other buffers do not have corresponding address enable signals and cannot store data. Then, the rising edge of the second clock pulse inputs the data from address 1 of matrix control metadata page 0 into buffer 1. The falling edge of the second clock pulse continues to increment the page address counter to 2, and simultaneously sends the address enable signal to buffer 2. Other buffers do not have corresponding address enable signals. Finally, the rising edge of the third clock pulse inputs the data from address 2 of matrix control metadata page 0 into buffer 1. Data is input into buffer memory 2, and the falling edge of the third pulse increments the page address counter by 1, making it 3... and so on, until the rising edge of the 48th pulse of the master clock signal inputs the data in page address 47 of the matrix control metadata page 0 into buffer memory 47. At this point, a total of 48 buffer memories (0 to 47) sequentially store 48 data entries from the matrix control page 0. Then, the falling edge of the 48th pulse increments the page address counter by 1, making it 48. At this point, the page address counter 48 is incremented by 1, achieving a carry-to-zero operation. Simultaneously, the generated carry signal increments the matrix control metadata address counter by 1, and the zero address enable signal is sent back to buffer memory 0. The carry pulse signal is also simultaneously sent to the latches of the 48 latches. The command input enables 48 latches to simultaneously receive data from 48 buffers, and these 48 latches simultaneously send this 48 data to the data inputs of 48 D / A converters. These D / A converters convert this data into 48 analog voltages, which control 48 piezoelectric ceramic sheets to change their thickness, thus completing the first morphological change of the reflector layer 7. The above cycle is then repeated. However, since the matrix control metadata page also carries simultaneously, the rising edge of the 49th pulse of the main clock signal inputs the data at address 0 of page 1 of the matrix control metadata page into buffer memory 0. This continues until buffers 0 to 47 have sequentially stored the 48 data from page 1 of the matrix control metadata page. Then, the carry pulse is sent again to the latch instruction input of the 48 latches.This allows 48 D / A converters to control the expansion and contraction of 48 piezoelectric ceramic sheets, completing the second morphological change of mirror layer 7.

[0062] Next, the master clock signal will continue the aforementioned timing process and repeat 1000 times. In this way, the thickness of each piezoelectric ceramic sheet 4 is in a continuous dynamic adjustment process throughout the exposure time, and the speckle moves without stopping, thus ensuring the performance of uniform light. When the matrix control element address counter reaches the set number, that is, when 1000 sets of matrix control element outputs are completed, the matrix control element address counter will send a signal to terminate the operation of the frequency divider 802, the master clock signal is interrupted, and then the frequency divider 802 waits for the next exposure signal to be triggered.

[0063] It should also be noted that this invention divides the entire reflector layer 7 into several sub-mirror regions. Each sub-mirror region groups the incident laser beam during reflection. Although the phase between groups changes dynamically, the phase of the beam within each group remains the same. In contrast, existing imaging systems include other components that can alter the beam relationship. For example, when the mask for chip lithography is square, to fully utilize the light energy, the original circular beam must be processed into a square beam with the same proportions as the mask. This processing device is a square beam homogenizer, and its specific processing method is... First, the circular beam is focused and converged so that the converged area is smaller than the entrance of the square beam homogenizer. This allows the beam to enter the square beam homogenizer without loss. Inside the square beam homogenizer is a square tube reflection device 901 of a certain length, surrounded by four highly reflective plane mirrors. Most of the light entering the square beam homogenizer undergoes multiple reflections inside the square tube reflection device 901 before exiting from the exit of the square beam homogenizer. Furthermore, the original beam relationship is completely disrupted during the output, preventing light rays with the same phase from simultaneously passing through the same area of ​​the mask within the same sub-mirror region. The structure and principle of the square beam homogenizer are well-known technologies in the art.

[0064] Furthermore, this invention improves upon the aforementioned square beam homogenizer structure to further enhance the spot-reducing effect, specifically as follows:

[0065] like Figures 15-16 As shown, the square beam homogenizer 9 of this utility model includes a fixed frame 902 and a square tube reflector 901 disposed in the fixed frame 902. The square tube reflector 901 is provided with four high-reflectivity plane mirrors that form a square tube shape. The above structure is a well-known technology in the art.

[0066] like Figures 15-16As shown, this utility model provides an input port reinforcing frame 9031 at the edge of the input port 903 of the square tube reflector 901. One side of the input port reinforcing frame 9031 in the left-right direction is connected to a first mounting piece 9041 on the corresponding inner wall of the fixed frame 902 via a first piezoelectric ceramic column 904, and the other side is connected to the corresponding inner wall of the fixed frame 902 via a first spring 907. One side of the input port reinforcing frame 9031 in the up-down direction is connected to a second mounting piece 9051 on the corresponding inner wall of the fixed frame 902 via a second piezoelectric ceramic column 905, and the other side is connected to the corresponding inner wall of the fixed frame 902 via a second spring 906. The first piezoelectric ceramic column 904 is provided with a first positive lead 9042 and a first negative lead 9043 for applying voltage. The second piezoelectric ceramic column 905 is provided with a second positive lead 9052 and a second negative lead 9043. Two negative leads 9053 are used to apply voltage. After randomly varying voltages are applied to these two pairs of control leads, the first piezoelectric ceramic pillar 904 and the second piezoelectric ceramic pillar 905 will expand and contract, thereby causing the input port 903 of the square tube reflector 901 to vibrate irregularly in the left-right and up-down directions. In this embodiment, the vibration amplitude of the input port 903 is controlled within ±1μm. Under the above vibration effect, the incident light will change at the incident point of the four reflectors. Therefore, the optical path through the square beam homogenizer 9 will also change slightly, thereby further ensuring that there will be no light rays with the same phase in the same sub-mirror area passing through the same area of ​​the mask at the same time. In addition, the light beam passing through the square beam homogenizer 9 will illuminate the continuously irregularly vibrating reflector layer 7, thereby further enhancing the speckle reduction effect.

[0067] like Figure 15 As shown, the first mounting plate 9041 is a thin sheet with a certain elasticity. The first mounting plate 9041 and the first spring 907 are used to cooperate to make the input port 903 of the square tube reflector 901 vibrate in the left and right direction. Similarly, the second mounting plate 9051 is also a thin sheet with a certain elasticity. The second mounting plate 9051 and the second spring 906 are used to cooperate to make the input port 903 of the square tube reflector 901 vibrate in the up and down direction.

[0068] like Figure 16As shown, the output port 908 of the square tube reflector 901 is provided with an output port reinforcing frame 9081 at its edge. Each side of the output port reinforcing frame 9081 is connected to the corresponding inner wall of the fixed frame 902 via a corresponding reinforcing frame mounting piece 9082. The reinforcing frame mounting piece 9082 is also a thin sheet with a certain degree of elasticity. This allows the output port 908 of the square tube reflector 901 to move adaptively within the allowable elastic deformation range of the reinforcing frame mounting piece 9082, thereby improving the service life of the device. Furthermore, the area of ​​the output port 908 is larger than that of the input port 903 and has an outward expansion angle.

Claims

1. A dynamic matrix reflector capable of converting laser light into incoherent laser light of the same frequency but different phase, characterized in that: The system includes a ceramic substrate (1) and a control system (8). The ceramic substrate (1) has multiple electrical connection blocks (2) on its lower side and multiple electrical connection disks (3) on its upper side. The control system (8) includes multiple output control units. The ceramic substrate (1) has multiple electrical connection holes (102). The lower side of each electrical connection block (2) is connected to the corresponding output control unit, and the upper side is electrically connected to the corresponding electrical connection disk (3) through the corresponding electrical connection hole (102). Each electrical connection disk (3) has a piezoelectric ceramic sheet (4) on its upper side. The upper edge of the ceramic substrate (1) has a ceramic frame (5), and each piezoelectric ceramic sheet (4) is located in the ceramic frame (5). A common electrode layer (10) is provided on the upper side of the ceramic frame (5) and each piezoelectric ceramic sheet (4). A reflector layer (7) is provided on the upper side of the common electrode layer (10). A common electrode pin (6) is provided on the edge of the ceramic substrate (1). The upper end of the common electrode pin (6) is connected to the common electrode layer (10), and the lower end is electrically connected to the power ground module provided on the control system (8). The piezoelectric ceramic sheet (4) includes a lower electrode metal layer (403), a piezoelectric ceramic layer (401), and an upper electrode metal layer (402) arranged sequentially from bottom to top. The lower electrode metal layer (403) is connected to the corresponding electrical connection disk (3), and the upper electrode metal layer (402) is connected to the common electrode layer (10).

2. The dynamic matrix reflector according to claim 1, capable of converting laser light into incoherent laser light of the same frequency but different phase, is characterized in that: The actuation distance of the piezoelectric ceramic layer (401) of the piezoelectric ceramic sheet (4) after being energized is within the range of ±6.75nm.

3. The dynamic matrix reflector according to claim 1, capable of converting laser light into incoherent laser light of the same frequency but different phase, is characterized in that: The electrical connection plate (3) includes multiple square blocks (301) arranged in a square matrix, and adjacent blocks (301) are connected by straight connecting strips (302). The diagonal ends of the electrical connection plate (3) are connected by diagonal connecting strips (303). An electrical connection hole (102) is provided at the intersection of the two diagonal connecting strips (303). The lower electrode metal layer (403) on the underside of the piezoelectric ceramic sheet (4) is welded to the corresponding block (301) of the electrical connection plate (3).

4. The dynamic matrix reflector according to claim 1, capable of converting laser light into incoherent laser light of the same frequency but different phase, is characterized in that: The ceramic substrate (1) has a substrate pin groove (101) on each side edge, and the ceramic frame (5) has a frame pin groove (501) on each side edge. Each frame pin groove (501) and each substrate pin groove (101) are connected in a one-to-one correspondence to form multiple pin mounting grooves. The common electrode pin (6) is embedded and fixed in the corresponding pin mounting groove.

5. The dynamic matrix reflector according to claim 4, capable of converting laser light into incoherent laser light of the same frequency but different phase, is characterized in that: The lower end of the common electrode pin (6) is provided with a right-angle bending plate, and the right-angle bending plate is fastened to the bottom surface of the ceramic substrate (1) to form a pin pad (601). The thickness of the pin pad (601) is the same as the thickness of the electrical connection block (2).

6. The dynamic matrix reflector according to claim 1, capable of converting laser light into incoherent laser light of the same frequency but different phase, is characterized in that: The control system (8) includes a data storage control unit (801), a frequency divider (802), and multiple output control units. The data storage control unit (801) internally includes a matrix control metadata page, a page address counter, and a matrix control metadata address counter. One end of the page address counter is connected to the frequency divider (802) via a clock data input line, and the other end is connected to one end of the matrix control metadata address counter via a first connection line. The other end of the matrix control metadata address counter is connected to the stop port on the frequency divider (802) via a second connection line. The output control units include a buffer memory (803), a latch (804), and a latch (805), all connected in sequence. The data storage control unit (801) is provided with an output control bus (8011) for outputting data from each matrix control metadata page. The output control bus (8011) includes multiple control branches, and each control branch is connected to a buffer memory (803) in the corresponding output control unit. The first connection line leads out a signal bus (8012), which includes multiple signal branches, and each signal branch is connected to a latch (804) in the corresponding output control unit. The D / A converter (805) is connected to the corresponding piezoelectric ceramic sheet (4).

7. The dynamic matrix reflector according to claim 6, capable of converting laser light into incoherent laser light of the same frequency but different phase, is characterized in that: The page address of the matrix control metadata page is counted by the page address counter, and the carry-to-zero number of the page address counter is equal to the number of output control units, both being A. The matrix control metadata page is counted by the matrix control metadata address counter.

8. The dynamic matrix reflector according to claim 1, capable of converting laser light into incoherent laser light of the same frequency but different phase, is characterized in that: The light incident side of the reflector layer (7) is provided with a square beam homogenizer (9).

9. The dynamic matrix reflector according to claim 8, capable of converting laser light into incoherent laser light of the same frequency but different phase, characterized in that: The square beam homogenizer (9) includes a fixed frame (902) and a square tube reflector (901) disposed in the fixed frame (902). The input port (903) edge of the square tube reflector (901) is provided with an input port reinforcing frame (9031). One side of the input port reinforcing frame (9031) in the left-right direction is connected to the first mounting plate (9041) on the corresponding side inner wall of the fixed frame (902) through the first piezoelectric ceramic column (904), and the other side is connected to the corresponding side inner wall of the fixed frame (902) through the first spring (907). One side of the input port reinforcing frame (9031) in the up-down direction is connected to the second mounting plate (9051) on the corresponding side inner wall of the fixed frame (902) through the second piezoelectric ceramic column (905), and the other side is connected to the corresponding side inner wall of the fixed frame (902) through the second spring (906).

10. The dynamic matrix reflector according to claim 9, capable of converting laser light into incoherent laser light of the same frequency but different phase, characterized in that: The square tube reflector (901) has an output port reinforcing frame (9081) at the edge of its output port (908), and each side of the output port reinforcing frame (9081) is connected to the inner wall of the corresponding side of the fixed frame (902) through a reinforcing frame mounting piece (9082) on the corresponding side.

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