CN117075431A - Measuring method for focal plane of exposure lens - Google Patents
Measuring method for focal plane of exposure lens Download PDFInfo
- Publication number
- CN117075431A CN117075431A CN202310752166.8A CN202310752166A CN117075431A CN 117075431 A CN117075431 A CN 117075431A CN 202310752166 A CN202310752166 A CN 202310752166A CN 117075431 A CN117075431 A CN 117075431A
- Authority
- CN
- China
- Prior art keywords
- test
- focal
- focal plane
- value
- unit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 23
- 238000012360 testing method Methods 0.000 claims abstract description 316
- 238000001259 photo etching Methods 0.000 claims abstract description 21
- 238000011161 development Methods 0.000 claims abstract description 8
- 238000012545 processing Methods 0.000 claims abstract description 6
- 238000012887 quadratic function Methods 0.000 claims description 6
- 238000001914 filtration Methods 0.000 claims description 5
- 238000001514 detection method Methods 0.000 claims description 4
- 238000001459 lithography Methods 0.000 abstract description 9
- 238000005259 measurement Methods 0.000 abstract description 6
- 230000007246 mechanism Effects 0.000 description 13
- 239000000758 substrate Substances 0.000 description 9
- 230000008859 change Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 238000003032 molecular docking Methods 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 1
- 238000007405 data analysis Methods 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 239000004579 marble Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229920002120 photoresistant polymer Polymers 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/70483—Information management; Active and passive control; Testing; Wafer monitoring, e.g. pattern monitoring
- G03F7/70605—Workpiece metrology
- G03F7/70616—Monitoring the printed patterns
- G03F7/70641—Focus
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
- G02B7/02—Mountings, adjusting means, or light-tight connections, for optical elements for lenses
- G02B7/04—Mountings, adjusting means, or light-tight connections, for optical elements for lenses with mechanism for focusing or varying magnification
- G02B7/09—Mountings, adjusting means, or light-tight connections, for optical elements for lenses with mechanism for focusing or varying magnification adapted for automatic focusing or varying magnification
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
- G02B7/28—Systems for automatic generation of focusing signals
- G02B7/36—Systems for automatic generation of focusing signals using image sharpness techniques, e.g. image processing techniques for generating autofocus signals
- G02B7/38—Systems for automatic generation of focusing signals using image sharpness techniques, e.g. image processing techniques for generating autofocus signals measured at different points on the optical axis, e.g. focussing on two or more planes and comparing image data
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/70483—Information management; Active and passive control; Testing; Wafer monitoring, e.g. pattern monitoring
- G03F7/7055—Exposure light control in all parts of the microlithographic apparatus, e.g. pulse length control or light interruption
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Engineering & Computer Science (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
- Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
Abstract
A measuring method of exposure lens focal plane of direct-writing lithography machine is based on basic focal plane value Z of exposure lens of direct-writing lithography machine 0 Determining a test focal value set Z n The test pattern comprises a plurality of unit test patterns which are arranged in rows and columns, and the test focal value group comprises a plurality of test focal values with different values, and each unit test pattern corresponds to one test focal value; setting a reference focal plane of the direct-writing photoetching machine as a test focal plane respectively, and exposing corresponding unit test patterns on a test workpiece respectively; after development is completed, an image of a unit test pattern is acquired through an image acquisition device, the acquired unit test image is subjected to data processing to obtain the amplitude of the unit test image on a diffraction domain, a test focal plane value and an amplitude fitting function curve on the diffraction domain are obtained, and the real focal of the exposure lens is obtainedThe surface has high measurement accuracy.
Description
Technical Field
The invention relates to the technical field of laser direct writing, in particular to a method for measuring the focal plane of an exposure lens of laser direct writing equipment.
Background
The existing actual focal plane measuring mode of the photoetching machine is a mode of fixing an exposure lens and moving a workbench for loading a workpiece in the vertical direction, and the workpiece is exposed at different heights by moving the workbench, and after the exposure is completed, the actual focal plane position of the photoetching machine is determined by utilizing a microscope or a CD-SEM (scanning electron microscope) to observe imaging quality or detecting the critical dimension of the exposed line. The measurement mode of measuring the critical dimension needs to be used by means of external equipment (such as a microscope and the like), so that the manual measurement error is large, the traceability is low, the error caused by the warping of the workpiece cannot be avoided, and the requirement of high-precision equipment cannot be met.
Disclosure of Invention
The invention aims to provide a focal plane measuring method of an exposure lens of high-precision equipment.
In order to solve the above problems, the present invention provides a method for measuring a focal plane of an exposure lens of a direct-writing lithography machine, according to a base focal plane value Z of the exposure lens of the direct-writing lithography machine 0 Determining a test focal value set Z n The test pattern comprises a plurality of unit test patterns which are arranged in rows and columns, and the test focal value group comprises a plurality of test focal values with different values, and each unit test pattern corresponds to one test focal value; setting a reference focal plane of the direct-writing photoetching machine as a test focal plane respectively, and exposing corresponding unit test patterns on a test workpiece according to the position relation of the test patterns; after the exposure is completed, developing operation is carried out on the test workpiece, after the development is completed, an image of a unit test pattern is acquired through an image acquisition device, an image of the unit test pattern corresponding to one test pattern forms a group of image data sets, the acquired unit test image is subjected to data processing to obtain the amplitude value of the unit test image on a diffraction domain, and the real focal plane of the exposure lens is obtained through fitting a function curve on the test focal plane value corresponding to the unit test image in the image data sets and the amplitude value on the diffraction domain.
Further, the unit test patterns are arranged in N rows and N columns, where N is a singular number not less than 3.
Further, based on the base focus value Z 0 In order to set the unit test pattern corresponding to the test focal plane at the center of the test pattern as the center test pattern, the unit test patterns corresponding to the rest test focal planes are arranged around the center test pattern.
Further, the positions of the unit test patterns corresponding to the test focal values are designed, so that the arrangement of the test focal values corresponding to each row of unit test patterns from small to large or from large to small is avoided; meanwhile, the arrangement of the test focal values corresponding to each column of unit test patterns from small to large or from large to small is avoided.
Further, the test focal value group Z n According to the basic focal value Z 0 Obtained by the basic focal value Z 0 The intermediate values are symmetrically floating up and down, when the test focal values in the test focal value group are arranged from small to large or from large to small, the difference value between the adjacent test focal values is the same unit focal value U 0 。
Further, the test focal plane value corresponding to the unit test image and the amplitude fitting function curve on the diffraction domain are quadratic function curves, and the focal plane value corresponding to the vertex of the function curve is the real focal plane of the exposure lens at the moment.
Further, after removing a larger deviation value by using Gaussian filtering, the quadratic function curve is obtained by fitting least squares data.
Further, when the test workpiece exposes the corresponding unit test pattern, the exposure dose used is greater than the optimum exposure dose for the test workpiece.
Further, the test piece has an alignment point, and the test piece with the alignment point is selected or exposed before the test pattern is exposed.
Further, the unit test pattern is a pattern arranged in an array.
The method comprises the steps that before a test pattern is exposed, surface shape data of a test workpiece is obtained through a height detection unit, and the automatic focusing device adjusts the focal plane of the exposure lens according to the height data so as to adapt to different heights of the test workpiece; the real focal plane of the exposure lens with the focusing device at the exposure test pattern of the test workpiece is measured by adopting the measuring method of the focal plane of the exposure lens, the moving distance of the automatic focusing device is calculated according to the obtained real focal plane of the exposure lens, and the control precision of the automatic focusing device is obtained by comparing and analyzing the moving distance with the height data of the test workpiece at the corresponding position.
Compared with the prior art, the real focal value is obtained by setting different test focal plane exposure unit test patterns, the test unit patterns are arranged in an array, the amplitude of the test pattern formed by the unit test patterns and the function curve of the test focal plane are obtained, the measurement accuracy is high, meanwhile, the test focal value corresponding to the unit test patterns in the row direction and/or the unit test patterns in the column direction in the test patterns has different numerical value rising directions and numerical value falling directions, and the first-order error caused by forming the inclined focal plane in the row direction and/or the column direction is avoided.
Drawings
FIG. 1 is a schematic diagram of a direct write lithography machine.
Fig. 2 is a schematic block diagram of a method of measuring a true focal plane of an exposure lens of a direct-write lithography machine.
FIG. 3 is a schematic diagram of a test focal plane corresponding to a test pattern according to an embodiment.
FIG. 4 is a schematic diagram of a test pattern according to an embodiment.
FIG. 5 is a schematic illustration of the completion of exposure of a test workpiece with a pair of sites.
FIG. 6 is a graph of amplitude versus test focal plane.
FIG. 7 is a schematic diagram of a test focal plane corresponding to a test pattern according to another embodiment.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the present invention is described below by means of specific embodiments shown in the accompanying drawings.
As shown in fig. 1, an example of a direct-write lithography machine is shown, which includes a base 1, a gantry mechanism 2, an exposure mechanism 3, a registration mechanism 4, a multi-axis motion stage (5, 6, 7), a substrate stage 8, and a control system. The control system controls the exposure mechanism 3, the alignment mechanism 4, the multi-axis motion stages (5, 6, 7) and the substrate stage 8. The base 1 is provided with a gantry mechanism 2 and multi-axis motion platforms (5, 6 and 7), the multi-axis motion platforms (5, 6 and 7) are provided with a substrate platform 8, and the gantry mechanism is provided with an alignment mechanism 4 and an exposure mechanism 3. The multi-axis motion platforms (5, 6 and 7) drive the substrate platform to move in the X direction, the Y direction and the Z direction, and the alignment system 4 and the exposure system 3 can be fixedly arranged with the gantry mechanism 2 or can be slidably arranged in the gantry mechanism 2.
The exposure mechanism 3 includes a plurality of exposure lenses 30, and the alignment mechanism 4 includes at least one image acquisition device 40, and the image acquisition device 40 is fixedly arranged or slidingly arranged.
The multi-axis motion platform (5, 6, 7) comprises a y-axis motion assembly 6, an x-axis motion assembly 5 and a z-axis motion assembly 7, wherein the y-axis motion assembly 6 is fixed on the marble base 1, the x-axis motion assembly 5 is fixed on the y-axis motion assembly 6, and the z-axis motion assembly 7 is fixed on the x-axis motion assembly 5. The X-axis movement assembly 5 drives the substrate platform 8 to move along the X direction, the Y-axis movement assembly 6 drives the substrate platform 8 to move along the Y direction, and the Z-axis movement assembly 7 drives the substrate platform 8 to vertically move along the Z axis.
It should be understood that the foregoing illustrates only an exemplary configuration of a conventional direct-writing lithography machine in the art, and in practical applications, the configuration may exist in various forms, for example, only one motion stage and substrate stage may be provided, two or more motion stages may be provided, the multiple axis motion stage reduces the x-axis motion assembly and/or the z-axis motion assembly as required, the exposure lens is fixedly mounted or movably mounted, and other conventional modifications are not listed one by one.
As shown in fig. 2, a method for measuring the true focal plane of the exposure lens of the direct-write lithography machine is specifically described below.
Basic focal value Z of exposure lens according to direct-writing photoetching machine 0 Determining a test focal value set Z n And a test pattern. The basic focal value Z 0 For the preliminary measurement of the rough focal plane value, the camera can move in the Z direction, images of static projection of the exposure lens are obtained at different Z direction heights, and the Z direction of the camera is fittedThe height and the image gray level, the Z direction height corresponding to the extreme point is the rough focal plane value of the exposure lens; or the mode of adjusting the height of the test workpiece in the Z direction is adopted, the exposure lens respectively exposes lines to the test workpiece when the test workpiece is at different heights, and the Z direction height corresponding to the exposed lines when the critical dimension (CD value) of the exposed lines is closest to the theoretical value is the coarse focal plane. Test focal plane value group Z n According to the basic focal value Z 0 Obtained by the basic focal value Z 0 The intermediate values are symmetrically floating up and down, when the test focal values in the test focal value group are arranged from small to large or from large to small, the difference value between the adjacent test focal values is the same unit focal value U 0 . The test patterns comprise a plurality of unit test patterns, the unit test patterns are arranged in N rows and N columns, N is the singular number not less than 3, and the N value can be selected according to the theoretical focal depth and the stepping value S of the exposure lens 0 Determining (N-1) S 0 And the step value refers to the unit relative movement distance of the lens and the workpiece. Each unit test pattern corresponds to a test focal value to base focal value Z 0 In order to set the unit test pattern corresponding to the test focal plane at the center of the test pattern as the center test pattern, the unit test patterns corresponding to the rest test focal planes are arranged around the center test pattern. Preferably, the positions of the unit test patterns corresponding to the test focal values are designed, so that the arrangement of the test focal values corresponding to each row of unit test patterns from small to large or from large to small is avoided; meanwhile, the arrangement of the test focal values corresponding to each column of unit test patterns from small to large or from large to small is avoided. Preferably, the unit test patterns are arranged in an array. Preferably, the pattern is a regular pattern such as a circle, a square, etc. The pattern is preferably of a minimum size that ensures complete pattern after exposure development. .
Exposing the unit test patterns on the test workpiece in sequence according to the test focal planes corresponding to the unit test patterns in the test patterns. Gaps are arranged between adjacent unit test patterns, so that the unit test pattern boundaries can be distinguished conveniently. Preferably, the exposure alignment points are exposed on the test workpiece before exposing the unit test patterns, and are used for aligning the unit test patterns, so that the positions among the unit test patterns can be conveniently and quickly positioned in the later stage. When the unit test patterns corresponding to the exposure of the workpiece are tested, the adopted exposure dose is larger than the optimal exposure dose of the workpiece, and the optimal exposure dose is the limit exposure dose corresponding to the limit resolution size which is perfectly realized by the exposure lens of the photoetching machine under the condition of dry film or photoresist support.
The exposed test workpiece is subjected to development treatment, so that tiny change of image characteristics can be observed more conveniently through the development treatment, and particularly, the condition of unobvious image distinction can be avoided for a high-precision machine with smaller lens focal depth. And placing the workpiece in the direct-writing type photoetching machine again, and acquiring the developed unit test pattern through an image acquisition module of the direct-writing type photoetching machine to obtain an image data set. The image dataset contains all unit test images corresponding to different positions, different test focal planes. Preferably, the position of the unit test pattern is accurately acquired based on the alignment point of the test workpiece, so that the unit test pattern is acquired more rapidly. The test piece with the docking sites may be selected directly or the docking sites may be exposed to the test piece prior to exposing the test pattern.
Image data processing is performed based on the acquired image dataset. And (3) taking all unit test image data in one test image as a group of analysis data, obtaining the amplitude value of the unit test image on a diffraction domain, obtaining the relation between the test focal plane value of the unit test image and the amplitude value on the diffraction domain, fitting a function curve, and finding the real focal plane of the exposure lens through the obtained function curve. When the function curve is fitted, the amplitude of the unit test image on the diffraction domain is taken as an ordinate, and the test focal value corresponding to the unit test image is taken as an abscissa. Preferably, before extracting the amplitude on the diffraction domain, denoising the full amplitude, filtering the noise, ensuring that each unit test image only comprises clear and complete unit test images, and if the obtained unit test image is in a '255' or '0' saturated state, adjusting the light source brightness of the image obtaining device, and re-obtaining the unit test image. Preferably, after removing a larger deviation value by Gaussian filtering, performing least squares data fitting to obtain a quadratic function curve of the amplitude and the test focal plane, wherein the focal plane value corresponding to the vertex of the function curve is the real focal plane of the direct-writing type photoetching machine. The amplitude of the unit test image on the diffraction domain is obtained through Fourier transformation of the gray value of the unit test image extracted by the image processing software. Preferably, the denoising processing is performed on the obtained unit test image before extracting the gray value of the unit test image, so that interference is avoided.
The real focal plane of the exposure lens of the direct-writing type photoetching machine can be obtained by exposing one test pattern or exposing a plurality of test patterns, obtaining a plurality of test data and obtaining the average value of the plurality of test data.
The test unit patterns are arranged in an array by setting different test focal plane exposure unit test patterns, the real focal plane value is obtained by acquiring the amplitude of the test patterns formed by the unit test patterns and the function curve of the test focal plane, the measurement accuracy is high, and meanwhile, the test focal plane value corresponding to the unit test patterns in the row direction and/or the unit test patterns in the column direction in the test patterns has different numerical value rising directions and numerical value falling directions, so that the first-order error is prevented from being introduced by forming the inclined focal plane in the row direction and/or the column direction.
In the following, as shown in fig. 3 to 7, a test pattern is illustrated as including 9 unit test patterns 10 arranged in three rows and three columns, the 9 unit test patterns respectively corresponding to 9 test focal values, respectively being Z 1 、Z 2 、Z 3 、Z 4 、Z 5 、Z 6 、Z 7 、Z 8 、Z 9 。
Test Jiao Mianzhi Z 1 To Z 9 From small to large, the intermediate value Z in the focal value group is tested 5 Is equal to the base focal value Z 0 。
And Z is 5 Adjacent Z 4 And Z 6 Respectively with Z 5 Unit focal plane value U differing by one time 0 ，Z 4 =Z 0 -U 0 ，Z 6 =Z 0 +U 0 。
Z 3 And Z 7 Respectively with Z 5 Unit focal values U that differ by a factor of two 0 ，Z 3 =Z 0 -2U 0 ，Z 7 ==Z 0 +2U 0 。
Z 2 And Z 8 Respectively with Z 5 Unit focal plane values U differing by three times 0 ，Z 2 =Z 0 -3U 0 ，Z 8 ==Z 0 +3U 0 。
Z 1 And Z 9 Respectively with Z 5 Unit focal values U four times different 0 ，Z 1 =Z 0 -4U 0 ，Z 9 ==Z 0 +4U 0 。
Among the test patterns, the first unit test pattern in the first row has a test focal value Z 9 The test focal value corresponding to the second unit test pattern positioned on the second position of the first row is Z 6 The test focal value corresponding to the third unit test pattern positioned in the third position of the first row is Z 3 The test focal value corresponding to the fourth unit test pattern positioned at the first position of the second row is Z 2 The test focal value corresponding to the fifth unit test pattern positioned at the second position of the second row is Z 5 The test focal value corresponding to the sixth unit test pattern positioned in the third position of the second row is Z 8 The test focal value corresponding to the seventh unit test pattern positioned at the first position of the third row is Z 7 The test focal value corresponding to the eighth unit test pattern positioned at the second position of the third row is Z 4 The test focal value corresponding to the ninth unit test pattern positioned in the third row and the third position is Z 1 . The unit test pattern at the center of the test pattern corresponds to a test focal value Z 5 In this embodiment, the test focal value is Z 5 For the center, two opposite test focus values for the center line and diagonal line are relative to test Jiao Mianzhi Z 5 Differing by the same number. It should be understood by those skilled in the art that the above embodiments are merely exemplary, and that the arrangement of the test focus values corresponding to the unit test patterns is such that the unit test patterns located in the middle among the test focus values corresponding to at least one row or each column of unit test patternsThe corresponding test focal plane value is the maximum value or the minimum value; for the situation that the test focal values corresponding to each row or each column of unit test patterns are arranged in a sequence from small to large or from large to small, the arrangement direction of the test focal values corresponding to at least one row or one column of unit test patterns is different from that of the rest rows and columns, and in the embodiment, the test focal values corresponding to one row of unit test patterns are arranged from left to right in a small to large arrangement mode, and the test focal values corresponding to the other two rows of unit test patterns are arranged from left to right in a large to small arrangement mode; similarly, the test focal values corresponding to one column of unit test patterns are arranged from top to bottom in a small-to-large manner, and the test focal values corresponding to the other two columns of unit test patterns are arranged from top to bottom in a large-to-small manner, so that first-order errors caused by forming inclined focal surfaces in the row direction and/or the column direction are avoided.
Setting the reference focal value of the direct-writing photoetching machine as Z 9 And adjusting the motion platform in the vertical direction to enable the test workpiece to be positioned on a reference focal plane, and exposing the first unit test pattern on the test workpiece. Setting the reference focal plane of the direct-writing photoetching machine as Z 2 And adjusting the vertical direction adjustment motion platform to enable the test workpiece to be positioned on the reference focal plane, horizontally adjusting the position of the workpiece, and exposing a fourth unit test pattern on the test workpiece according to the position relation of the test pattern. Setting the reference focal plane of the direct-writing photoetching machine as Z 7 And adjusting the vertical direction adjustment motion platform to enable the test workpiece to be positioned on the reference focal plane, horizontally adjusting the position of the workpiece, and exposing a seventh unit test pattern on the test workpiece according to the position relation of the test pattern. And so on, the exposure of the test image to the test workpiece is completed according to the sequence shown in fig. 4.
And developing the exposed test workpiece, placing the test workpiece subjected to the developing operation on a motion platform of a direct-writing type photoetching machine, acquiring a test image through an image acquisition device, obtaining an image data set of the unit test image, and performing image data processing. And removing the larger deviation value by Gaussian filtering, and performing least squares data fitting, so as to obtain a quadratic function curve of the amplitude and the test focal plane, wherein the focal plane value corresponding to the peak of the function curve is the real focal plane of the direct-writing photoetching machine.
Before exposing the test pattern, the opposite point 20 can also be exposed on the test substrate for positioning the exposed test pattern, so that the test image can be quickly grasped after development is completed.
The method for obtaining the real focal plane of the direct-writing type photoetching machine can also be applied to the direct-writing type photoetching machine with an automatic focusing device and used for measuring the control precision of the focusing device. The automatic focusing device is used for adjusting the focal plane of the exposure lens according to the height change of the workpiece.
Before exposing the test pattern, the height detection unit is used for acquiring the surface shape data of the test workpiece, and the automatic focusing device is used for adjusting the focal plane of the exposure lens according to the surface shape data so as to adapt to different heights of the test workpiece.
When the test image exposure is carried out on the test workpiece, reference focal planes are respectively set, the automatic focusing device carries out focal plane adjustment according to the surface shape data of the test workpiece, unit test pattern exposure corresponding to the reference focal planes is completed, after exposure of all unit test patterns is completed, development operation is carried out on the exposed workpiece, test images are acquired through the image acquisition device, data analysis is carried out on the test images, real focal planes at corresponding positions are obtained, the surface shape of the real focal planes of the test workpiece is fitted according to the obtained real focal planes of the whole plate surface of the test workpiece and the positions (X and Y) of the test workpiece corresponding to each real focal plane, and meanwhile, comparison is carried out with the surface shape data of the test workpiece acquired by the height detection unit, so that whether the focal plane value compensated by the automatic focusing device is correct or not and whether the direction is correct or not is verified. Specifically, according to the obtained real focal plane, calculating the moving distance of the automatic focusing device, comparing and analyzing the moving distance of the automatic focusing device with the height data of the test workpiece at the corresponding position, comparing whether the moving distance of the automatic focusing device corresponds to the height change (theoretical moving distance) of the test workpiece, obtaining the control precision of the automatic focusing device, and judging whether the control precision of the automatic focusing device is qualified. If the height change of the test workpiece and the moving distance of the automatic focusing device are within the error range, the control precision of the automatic focusing device meets the requirements, and if the height change of the test workpiece and the moving distance of the automatic focusing device are beyond the error range, the control precision of the automatic focusing device does not meet the requirements and needs to be corrected.
When the control precision of the focusing device is measured, a mode of acquiring a plurality of groups of exposure image data can be adopted, a test focal plane is set as a reference focal plane, the automatic focusing device carries out focal plane adjustment according to the height data of a test workpiece, completes exposure of a plurality of unit test patterns corresponding to the reference focal plane according to the position relation of the test patterns, completes exposure of all unit test patterns corresponding to one test focal plane, and carries out exposure of a plurality of unit test patterns corresponding to the next test focal plane. And exposing the unit test patterns corresponding to all the test focal planes until the exposure of the unit test patterns corresponding to all the test focal planes is completed.
Claims (11)
1. A method for measuring the focal plane of an exposure lens of a direct-writing photoetching machine is characterized by comprising the following steps: basic focal value Z of exposure lens according to direct-writing photoetching machine 0 Determining a test focal value set Z n The test pattern comprises a plurality of unit test patterns which are arranged in rows and columns, and the test focal value group comprises a plurality of test focal values with different values, and each unit test pattern corresponds to one test focal value; setting a reference focal plane of the direct-writing photoetching machine as a test focal plane respectively, and exposing corresponding unit test patterns on a test workpiece according to the position relation of the test patterns; after the exposure is completed, developing operation is carried out on the test workpiece, after the development is completed, an image of a unit test pattern is acquired through an image acquisition device, an image of the unit test pattern corresponding to one test pattern forms a group of image data sets, the acquired unit test image is subjected to data processing to obtain the amplitude value of the unit test image on a diffraction domain, and the real focal plane of the exposure lens is obtained through fitting a function curve on the test focal plane value corresponding to the unit test image in the image data sets and the amplitude value on the diffraction domain.
2. The method for measuring the focal plane of an exposure lens according to claim 1, wherein: the unit test patterns are arranged in N rows and N columns, and N is the singular number not less than 3.
3. The method for measuring the focal plane of an exposure lens according to claim 1, wherein: based on the base focal value Z 0 In order to set the unit test pattern corresponding to the test focal plane at the center of the test pattern as the center test pattern, the unit test patterns corresponding to the rest test focal planes are arranged around the center test pattern.
4. The method for measuring a focal plane of an exposure lens according to claim 3, wherein: designing the positions of the unit test patterns corresponding to the test focal values, and avoiding the arrangement of the test focal values corresponding to each row of unit test patterns from small to large or from large to small; meanwhile, the arrangement of the test focal values corresponding to each column of unit test patterns from small to large or from large to small is avoided.
5. The method for measuring the focal plane of an exposure lens according to claim 1, wherein: the test focal plane value group Z n According to the basic focal value Z 0 Obtained by the basic focal value Z 0 The intermediate values are symmetrically floating up and down, when the test focal values in the test focal value group are arranged from small to large or from large to small, the difference value between the adjacent test focal values is the same unit focal value U 0。
6. The method for measuring the focal plane of an exposure lens according to claim 1, wherein: the test focal plane value corresponding to the unit test image and the amplitude fitting function curve on the diffraction domain are quadratic function curves, and the focal plane value corresponding to the vertex of the function curve is the real focal plane of the exposure lens at the moment.
7. The method for measuring the focal plane of an exposure lens according to claim 6, wherein: and removing a larger deviation value by using Gaussian filtering, and then performing least squares data fitting to obtain the quadratic function curve.
8. The method for measuring the focal plane of an exposure lens according to claim 1, wherein: when the corresponding unit test pattern is exposed to the test workpiece, the exposure dose adopted is larger than the optimal exposure dose of the test workpiece.
9. The method for measuring the focal plane of an exposure lens according to claim 1, wherein: the test workpiece is provided with an opposite site, and the opposite site is selected or exposed on the test workpiece before the test pattern is exposed.
10. The method for measuring the focal plane of an exposure lens according to claim 1, wherein: the unit test patterns are patterns arranged in an array.
11. A measuring method of exposure lens focal plane control precision of a direct-writing photoetching machine with a focusing device is characterized by comprising the following steps: before exposing the test pattern, acquiring surface shape data of a test workpiece through a height detection unit, and adjusting a focal plane of an exposure lens by the automatic focusing device according to the height data to adapt to different heights of the test workpiece; measuring the real focal plane of the exposure lens with the focusing device at the exposure test pattern of the test workpiece by adopting the measuring method of the focal plane of the exposure lens according to any one of claims 1-11, calculating the moving distance of the automatic focusing device according to the obtained real focal plane of the exposure lens, and comparing and analyzing the moving distance with the height data of the test workpiece at the corresponding position to obtain the control precision of the automatic focusing device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310752166.8A CN117075431A (en) | 2023-06-25 | 2023-06-25 | Measuring method for focal plane of exposure lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310752166.8A CN117075431A (en) | 2023-06-25 | 2023-06-25 | Measuring method for focal plane of exposure lens |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117075431A true CN117075431A (en) | 2023-11-17 |
Family
ID=88710354
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310752166.8A Pending CN117075431A (en) | 2023-06-25 | 2023-06-25 | Measuring method for focal plane of exposure lens |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117075431A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117452782A (en) * | 2023-12-08 | 2024-01-26 | 魅杰光电科技(上海)有限公司 | Image focusing method and image focusing system |
-
2023
- 2023-06-25 CN CN202310752166.8A patent/CN117075431A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117452782A (en) * | 2023-12-08 | 2024-01-26 | 魅杰光电科技(上海)有限公司 | Image focusing method and image focusing system |
| CN117452782B (en) * | 2023-12-08 | 2024-04-09 | 魅杰光电科技(上海)有限公司 | Image focusing method and image focusing system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9940703B2 (en) | Method of measuring a property of a target structure, inspection apparatus, lithographic system and device manufacturing method | |
| JP6880032B2 (en) | Methods and equipment for inspection | |
| US20160370710A1 (en) | Method of Metrology, Inspection Apparatus, Lithographic System and Device Manufacturing Method | |
| JPH04503410A (en) | Method and apparatus for measuring alignment between semiconductor wafer layers | |
| KR20080059572A (en) | Optical characteristic measuring method, exposure method, device manufacturing method, inspecting apparatus and measuring method | |
| KR20030036084A (en) | Exposure method and device therefor | |
| US10990024B2 (en) | Lithographic thermal distortion compensation with the use of machine learning | |
| JP3211491B2 (en) | Projection exposure apparatus and semiconductor manufacturing method and apparatus using the same | |
| US11194258B2 (en) | Method and apparatus for determining a fingerprint of a performance parameter | |
| CN117075431A (en) | Measuring method for focal plane of exposure lens | |
| KR20120092662A (en) | Optical characteristic measurement method, exposure method and device manufacturing method | |
| US5666205A (en) | Measuring method and exposure apparatus | |
| CN116183607A (en) | Defect automatic detection device and focusing method for defect detection | |
| WO2022122546A1 (en) | Method of metrology and associated apparatuses | |
| CN107024185B (en) | Method and device for measuring basal surface | |
| CN111624856B (en) | Mask plate, motion table positioning error compensation device and compensation method | |
| WO2017178285A1 (en) | Method for adjusting actuation of a lithographic apparatus | |
| JP7362594B2 (en) | Exposure system alignment and calibration methods | |
| CN111694226B (en) | Levelness measuring method and direct imaging device | |
| CN102169294B (en) | Method for measuring scanning inclination of mask table in scanning mask aligner | |
| US9424636B2 (en) | Method for measuring positions of structures on a mask and thereby determining mask manufacturing errors | |
| CN100399529C (en) | Detection apparatus and method for exposure device | |
| CN109690412B (en) | Method of determining characteristics of structure, inspection apparatus, and device manufacturing method | |
| CN112384861A (en) | Real-time autofocus for maskless lithography on a substrate | |
| WO2020096731A1 (en) | Signal recognition during substrate patterning via digital photolithography |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |