CN211718046U - Dull and stereotyped granularity check out test set - Google Patents
Dull and stereotyped granularity check out test set Download PDFInfo
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- CN211718046U CN211718046U CN202020301321.6U CN202020301321U CN211718046U CN 211718046 U CN211718046 U CN 211718046U CN 202020301321 U CN202020301321 U CN 202020301321U CN 211718046 U CN211718046 U CN 211718046U
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Abstract
The utility model discloses a dull and stereotyped granularity check out test set includes: a light source unit for emitting a detection beam; the dodging unit at least comprises a micro-lens array group and is positioned on a transmission path of the detection light beam, and the detection light beam forms a Talbot lattice light beam on a focal plane of the dodging unit after passing through the dodging unit; the Talbot lattice light beam incident on the flat plate to be detected is scattered by foreign matters in the flat plate to be detected to form a light beam to be imaged; the particle size information of foreign matters carried by the light beam to be imaged; the distance between two adjacent beams in the Talbot lattice beams is smaller than the particle size of the foreign matter; and the imaging unit is used for collecting the light beam to be imaged and detecting the foreign matters in the flat plate to be detected according to the light beam to be imaged. The light irradiated to the detected foreign matter is favorably ensured to be the superposition of the light emitted by the micro lenses, and further the surface uniformity and the angle uniformity of the detection light beam incident to the flat plate to be detected are favorably ensured to be good, wherein the angle uniformity can reach 90 percent, and the surface uniformity can reach 95 percent.
Description
Technical Field
The embodiment of the utility model provides a relate to optics technical field, especially relate to a dull and stereotyped granularity check out test set.
Background
In the manufacturing process of semiconductor integrated circuits or flat panel displays, pollution control is a crucial link for improving product yield. Before exposure, a mask plate, a silicon wafer, a glass substrate or the like needs to be subjected to foreign matter detection (including foreign particles, fingerprints, scratches, pinholes and the like). In the prior art, particle detection devices integrated in the lithographic apparatus are generally used for detection, the detection principle of the device is a dark field scatterometry principle, and in order to improve the detection efficiency, the current detection mode generally adopts a line scanning mode. The problem that it exists is, when adopting line scanning mode to detect, generally need line illumination, but the facula homogeneity that line illumination light source formed on surveying the plane is poor, like this, to the formation of image of later stage formation of image detector go on assay to and the detection of foreign matter has caused very big difficulty.
SUMMERY OF THE UTILITY MODEL
The utility model provides a dull and stereotyped granularity check out test set to acquire the detection light beam that angular distribution and face distribute evenly.
In order to achieve the above object, the utility model provides a dull and stereotyped granularity check out test set, include:
a light source unit for emitting a detection beam;
the dodging unit at least comprises a micro-lens array group, the dodging unit is positioned on a transmission path of the detection light beam, and the detection light beam forms a Talbot lattice light beam at a focal plane of the dodging unit after passing through the dodging unit; the Talbot lattice light beam incident on the flat plate to be detected is scattered by foreign matters in the flat plate to be detected to form a light beam to be imaged; the light beam to be imaged carries the particle size information of the foreign matter; the distance between two adjacent beams in the Talbot lattice beams is smaller than the particle size of the foreign matter;
and the imaging unit is positioned on the transmission path of the light beam to be imaged and used for collecting the light beam to be imaged and detecting the foreign matters in the flat plate to be detected according to the light beam to be imaged.
Optionally, the dodging unit further comprises: the first shaping lens group is positioned on a transmission path of the Talbot lattice light beam and is used for expanding or compressing the Talbot lattice light beam.
Optionally, the microlens array group comprises two groups of microlens arrays, each group of microlens arrays comprises a plurality of microlenses arranged in an array; the number of microlenses in each set of the microlens array is greater than or equal to 20.
Optionally, the microlens array group comprises two groups of microlens arrays, each group of microlens arrays comprises a plurality of microlenses arranged in an array; the distance between adjacent micro lenses in each group of micro lens array ranges from 0.2mm to 3 mm.
Optionally, a ratio of a pitch between adjacent microlenses in each group of the microlens array to a focal length of the microlens array is less than 1: 15.
Optionally, the microlens array set comprises a first microlens array and a second microlens array; the first microlens array is located in a first microlens structure and the second microlens array is located in a second microlens structure;
the first microlens structure further comprises a first plane; the second microlens structure further comprises a second plane; the first microlens array, the first plane, the second plane and the second microlens array are arranged in sequence along the transmission direction of the detection light beam.
Optionally, the microlens array set includes a third microlens array and a fourth microlens array, both of which are located in a third microlens structure.
Optionally, the light source unit includes: the light source expansion assembly is positioned on the light emitting side of the point light source and used for expanding the point light beams emitted by the point light source to form line light beams.
Optionally, the point light source is a coherent light source.
Optionally, the light source expansion assembly comprises at least one of a cylindrical lens and a cylinder-like lens.
Optionally, the flat panel particle size detection apparatus further includes a second shaping lens group, located on a transmission path of the detection beam, for collimating the detection beam.
Optionally, the imaging unit comprises a third shaping lens group and a detector, and the third shaping lens group is used for collecting the light beam to be imaged; the detector is used for receiving the light beam to be imaged and detecting the foreign matter in the flat plate to be detected according to the light beam to be imaged.
According to the utility model provides a dull and stereotyped granularity check out test set is through setting up even light unit for the detection light beam of light source unit outgoing forms the Talbot dot matrix light beam in the focal plane department of even light unit, and the foreign matter scattering formation in the flat board of waiting to measure of Talbot dot matrix light beam, and then, the foreign matter that the formation of image unit was treated according to waiting to form an image the light beam and surveyed in the flat board detects. The interval between two adjacent beams of light in the Talbot dot matrix light beam is smaller than the particle size of the foreign matter, so that the light irradiated to any detected foreign matter is favorably ensured to be superposed by the light emitted by the plurality of micro lenses, and the uniformity of the surface of the detection light beam incident to the flat plate to be detected and the uniformity of the angle are favorably ensured to be good, so that the detection precision of the imaging unit for detecting the foreign matter in the flat plate to be detected is higher, wherein the uniformity of the angle can reach 90 percent, and the uniformity of the surface can reach 95 percent.
Drawings
FIG. 1 is a schematic diagram of a prior art flat-panel particle size detection apparatus;
FIG. 2 is a schematic diagram of another prior art flat panel particle size detection apparatus;
fig. 3 is a schematic structural diagram of a flat-plate particle size detection apparatus according to an embodiment of the present invention;
fig. 4 is a schematic diagram of a detection surface in the flat-plate granularity detecting apparatus according to an embodiment of the present invention;
fig. 5 is a schematic structural diagram of a flat-plate particle size detection apparatus according to an embodiment of the present invention;
fig. 6 is an ideal optical path schematic diagram of a plate granularity detecting apparatus according to an embodiment of the present invention without a microlens array set;
fig. 7 is a schematic diagram of an actual light path of a flat-panel granularity detecting apparatus according to an embodiment of the present invention without a microlens array set;
FIG. 8 is a graph showing the result of the distribution of the energy values of the light intensity in the x direction in FIG. 7;
FIG. 9 is a graph showing the result of the angle of incidence of the panel under test in the x-direction in FIG. 7;
fig. 10 is a graph showing the result of the scattering efficiency of the flat panel particle size detecting apparatus according to an embodiment of the present invention varying with the direction angle;
fig. 11 is a schematic structural diagram of a light uniformizing unit in a flat-plate granularity detecting apparatus according to an embodiment of the present invention;
fig. 12 is a schematic structural diagram of a light uniformizing unit in the flat-panel granularity detecting apparatus according to an embodiment of the present invention;
fig. 13 is a schematic structural diagram of a microlens array in a flat-panel granularity detecting apparatus according to another embodiment of the present invention;
fig. 14 is a schematic structural diagram of a flat-plate particle size detection apparatus according to another embodiment of the present invention;
fig. 15 is a schematic structural diagram of a light source unit and a light uniformizing unit in the flat-plate granularity detecting apparatus according to the embodiment of the present invention;
fig. 16 is a surface distribution result diagram of light spots on the detection surface of the flat-plate particle size detection apparatus according to an embodiment of the present invention;
fig. 17 is a result diagram of angular distribution of light spots on a detection surface of the flat-plate granularity detection apparatus according to an embodiment of the present invention;
fig. 18 is a scattering efficiency distribution diagram of a flat-panel particle size detection apparatus according to an embodiment of the present invention;
fig. 19 shows a nominal value of scattering efficiency at an orientation angle of 137 degrees for a flat panel particle size detection apparatus according to an embodiment of the present invention;
fig. 20 is a graph showing the variation of scattering efficiency between 135 and 139 degrees in the direction angle in the flat-panel particle size detecting apparatus according to an embodiment of the present invention;
fig. 21 is a graph showing scattering efficiency fluctuation at each position of a field of view where no microlens array set is added to the flat-panel granularity detection apparatus according to an embodiment of the present invention;
fig. 22 is a diagram illustrating scattering efficiency fluctuation at each position of a field of view in a flat-panel particle size detection apparatus according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
FIG. 1 is a schematic structural diagram of a flat-panel particle size detection apparatus in the prior art. The particle detection apparatus, which is typically integrated in a lithographic apparatus, typically employs dark field scatterometry techniques, and the flat panel particle size detection apparatus 100 is shown in fig. 1. Light 101 emitted from the radiation light source 10 is scattered by foreign matter in the mask 40 on the mask stage 30, and the scattered signal light 102 enters the detection unit 20. However, the structure of the detection apparatus 100 is affected by the particle mirror image crosstalk (especially serious when the lower surface of the mask is chrome) and pattern crosstalk on the lower surface of the mask, which can seriously affect the signal-to-noise ratio of the detection signal, and further affect the detection accuracy.
In order to solve the above problems, a flat-panel particle size detection apparatus 200 as shown in fig. 2 is proposed in the later stage, which solves the above problem of particle image crosstalk and pattern crosstalk by controlling the incident angle 50, the receiving angle 60 and the constraints of the illumination field. Among them, the detecting unit 20 generally uses a multi-line TDI camera, and when the detecting imaging is performed by using the camera, the radiation light source 10 (point illumination) needs to be synchronously expanded to a line illumination light source.
However, the angular uniformity and the surface uniformity of the line illumination light source are not good at present, and when the line illumination light source irradiates the mask 40 on the mask table 30, the line illumination light source with poor angular uniformity and surface uniformity in the mask 40 scatters the foreign matters, and finally the foreign matters in the mask 40 are detected through the scattered light intensity. The scattering light intensity is the product of the scattering efficiency and the incident light intensity, the scattering efficiency is greatly influenced by the change of the direction angle (the incident angle 50+ the receiving angle 60), and if the incident light intensity is not uniform at this time, the final scattering light intensity is greatly influenced by the change of the direction angle. Since the flat particle detection device itself has an assembly error, when the final detection unit 20 performs detection, the assembly error may affect the direction angle and further affect the received scattered light intensity, thereby causing an error in the detection result.
To the above problem, the utility model provides a dull and stereotyped granularity detection device through setting up microlens array group, can form the facula that angular distribution homogeneity exceeds 90%, and face distribution homogeneity exceeds 95% on the dull and stereotyped detection face that awaits measuring.
Fig. 3 is a flat-plate particle size detection apparatus 300 according to an embodiment of the present invention. As shown in fig. 3, the flat panel particle size detecting apparatus 300 includes: a light source unit 301, a light uniformizing unit 307, and an imaging unit 316.
The light source unit 301 is used for emitting a detection light beam 304; the dodging unit 307 at least comprises a micro-lens array group which is positioned on the transmission path of the detection light beam 304, and after the detection light beam 304 passes through the dodging unit 307, a Talbot lattice light beam 309 is formed at the focal plane 310 of the dodging unit 307; the Talbot lattice light beam 309 incident on the flat plate 311 to be detected is scattered by the foreign matter 312 in the flat plate 311 to be detected to form a light beam 313 to be imaged; the light beam to be imaged 313 carries the particle size information of the foreign matter 312; the distance between two adjacent beams in the Talbot lattice beam 309 is smaller than the particle size of the foreign matter 312; the imaging unit 316 is located on the transmission path of the light beam 313 to be imaged, and is used for collecting the light beam 313 to be imaged and detecting the foreign matter 312 in the flat plate 311 to be detected according to the light beam to be imaged.
The foreign material 312 may be particles, scratches, fingerprints, or pinholes. The particle size of the foreign substance 312 may be a diameter of a particle, a line width of a scratch, an aperture of a pinhole, and a line width of a ridge of a fingerprint, that is, the particle size information of the foreign substance 312.
In the detection of the flat plate 311 to be detected, the influence of the contamination (i.e., the foreign substance 312) can be compared with the standard polystyrene beads. If the scattering properties of the contamination are similar to polystyrene beads of a certain size, the contamination effect produced by the contamination can be made equivalent to that of beads of that size. If the contamination is irregular, the contaminated area may be divided into a plurality of smaller areas, the effect of each small area being compared to one pellet. At this time, the total effect generated can be regarded as the sum of the effects of the plurality of pellets. That is, if the detected foreign substance 312 is a scratch, the scratch may be divided into a plurality of segments, and in the case of finer division, if the scratch line width is greater than the grain size, the scratch per segment may be equivalent to a plurality of grains; if the scratch line width is smaller than the grain size, the scratch per segment can be equivalent to a portion of one grain.
In addition, the flat panel 311 to be tested may be a mask plate, a silicon wafer or a glass substrate.
In the orientation shown in fig. 3, the foreign object 312 may be located on the upper surface of the flat board 311 to be measured, or may be located in the flat board 311 to be measured, in this example, the foreign object 312 is taken as a particle and is located on the upper surface of the flat board 311 to be measured (which is a mask plate).
It is understood that after the detection beams 304 are sequentially incident on the microlens array set in the dodging unit 307, the emergent beams 309 interfere with each other to form interference fringes on the focal plane 310, which is the Talbot (Talbot) effect (as shown in fig. 4). When the talbot lattice beam 309 is incident on the particles 312 in the flat plate 311 to be detected, the talbot lattice beam 309 is absorbed and scattered by the particles 312, the beam 313 to be imaged deviates from the propagation direction of the talbot lattice beam 309 and is scattered all around, wherein the spatial distribution rule of the scattered light intensity generated by the beam 313 to be imaged is related to the particle size of the particles 312, and the imaging unit 316 detects the particles in the flat plate 311 to be detected according to the spatial light intensity distribution rule of the beam 313 to be imaged and an inversion algorithm. I.e., the particle size information of the detected foreign matter 312.
By restricting the distance (d in fig. 4) between two adjacent beams in the talbot lattice beam 309 to be smaller than the particle size of the particle 312, it can be ensured that the light irradiated on the particle 312 is the superposition of the emergent light of a plurality of microlenses, and further the angular uniformity and the surface uniformity of the light are ensured to be good.
The light source unit 301, the light uniformizing unit 302, and the imaging unit 316 are described in this order.
Alternatively, as shown in fig. 3, the light source unit 301 includes: the light source expansion assembly 303 is positioned on the light emitting side of the point light source 302 and used for expanding the point light beam 306 emitted by the point light source 302 to form a line light beam. The line beam is the detection beam 304.
Optionally, the point light source 302 is a coherent light source. The coherent light source is preferably a laser light source. So that interference fringes are formed on the focal plane 310.
Optionally, the light source expansion assembly 303 comprises at least one of a cylindrical lens and a cylinder-like lens.
The cylinder-like lens may be a Powell prism to expand the spot length of the point light source 302.
Optionally, as shown in fig. 5, the flat-panel particle size detection apparatus 300 further includes a second shaping lens group 305, and the second shaping lens group 305 is located on a transmission path of the detection beam 304 and is used for collimating the detection beam 304.
The second shaping lens group 305 is a collimating lens, i.e. a double spherical lens, a double cemented lens, etc., to collimate the detection beam 304.
It should be noted that, when the point light source is expanded to a line light source, in order to ensure uniformity of each point as much as possible, the light source expansion component 303 (such as a cylindrical lens) is usually used to expand the spot length, and then the second shaping lens group 305 is used to perform collimation, which is simple and compact.
The ideal optical path of the light source unit 301 is shown in fig. 6, and the final scattered light intensity is Iresult(x)＝ηθIDS(x) Wherein etaθScattering efficiency corresponding to the angle between the incident direction and the scattering direction (or scattering angle)DSIs the particles 312 on the flat 311 to be measuredThe light intensity of the incident light corresponding to the position.
However, in practical operation, due to the process limitation of the second shaping lens group 305, the point light source 302 in the light source unit 301 passes through the light source expansion component 303, and then actually forms the detection beam 304 as shown in fig. 7, and after passing through the second shaping lens group 305, it is distributed on the flat panel 311 to be measured. In this case, if the line beam scan is required to cover the active area of the reticle (plate 311 to be measured), the overall uniformity is usually only maintained at 60% -70% (actual measurements are shown in FIG. 8). In addition, the incident angles at the respective positions are also different from the center of the illumination visual field to the edge of the illumination visual field (as shown in fig. 9).
At this time, if the detected particle size is equivalent to the wavelength of the light source (or about 10 times the wavelength), the illumination intensity and the illumination angle are determined by the position of the particle in the longitudinal direction (perpendicular to the scanning direction), i.e., Iresult(x)＝η(θx)IDS(x) Where eta (theta)x) Scattering efficiency corresponding to the angle between the incident direction and the scattering direction (or called direction angle)DS(x) The incident light intensity of the particle at a position corresponding to the flat plate 311 to be measured.
Since the flat panel particle inspection apparatus 300 employs the dark field scatterometry technique, the effective particle scattering signals thereof all conform to the Mie scattering theory, and when the direction angle changes, the scattering efficiency fluctuates between a maximum value and a minimum value (where the fluctuation image is shown in fig. 10). If the uniformity of the incident light intensity is 67% according to the variation of the scattering angle ± 1 degree, the final scattering light intensity, i.e. the difference between the maximum value and the minimum value, of the incident light intensity will be amplified by at least 2 times under specific conditions (for example, when the incident light intensity is minimum and the scattering efficiency is minimum, or when the incident light intensity is maximum and the scattering efficiency is maximum).
Based on this, the light unifying unit 307 is added in the present example, and the light unifying unit 307 is described in detail below.
Fig. 11 is a schematic structural diagram of a dodging unit in a flat-plate granularity detecting apparatus according to an embodiment of the present invention. As shown in fig. 3 and 11, the light unifying unit 307 includes a microlens array group including a first microlens array 3071a and a second microlens array 3072 a; the first microlens array 3071a is located in the first microlens structure 3071, and the second microlens array 3072a is located in the second microlens structure 3072;
the first microlens structure 3071 further includes a first plane 3071 b; second microlens structure 3072 also includes a second plane 3072 b; the first microlens array 3071a, the first plane 3071b, the second plane 3072b and the second microlens array 3072a are arranged in sequence along the direction in which the detection light beam 309 travels.
That is, as shown in fig. 3 and 11, the first microlens structure 3071 and the second microlens array structure 3072 are both single microlens arrays and are disposed opposite to each other.
Alternatively, in another embodiment, the structure of the microlens array set may also be as shown in fig. 12, the microlens array set includes a third microlens array 3073a and a fourth microlens array 3073b, and both the third microlens array 3073a and the fourth microlens array 3073b are located in the third microlens structure 3073.
That is, the third microlens structure 3073 is a double microlens structure.
Optionally, fig. 13 is a schematic structural diagram of a microlens array in a flat-panel granularity detecting apparatus according to another embodiment of the present invention. The microlens array set includes two groups of microlens arrays, as shown in fig. 13, each group of microlens arrays includes a plurality of microlenses arranged in an array; the number of microlenses in each set of microlens arrays is greater than or equal to 20.
The microlens array in fig. 13 is any one of the first microlens array 3071a, the second microlens array 3072a, the third microlens array 3073a, and the fourth microlens array 3073b described above. Taking the first microlens array 3071a as an example, wherein the number of periods of the microlens array in a certain direction is at least greater than 7, that is, if the overall shape of the microlens array is rectangular, m microlenses are arranged on the rectangle along the direction parallel to the long side, and n microlenses are arranged along the direction parallel to the short side, that is, the microlens array is arranged in m × n matrix, where m >7, or n > 7). As shown in fig. 13, m-n-8, the number of microlenses in the microlens array is 64.
Alternatively, the microlens array set includes two groups of microlens arrays, as shown in fig. 13, each group of microlens arrays includes a plurality of microlenses arranged in an array; the distance between the adjacent microlenses in each microlens array is in the range of 0.2mm to 3mm, wherein the distance between the adjacent microlenses in each microlens array can be p, and p is preferably 0.2 mm.
Optionally, a ratio of a pitch between adjacent microlenses in each group of microlens arrays to a focal length of the microlens arrays is less than 1: 15.
It should be noted that, for the microlens array generating the Talbot effect, there exist a plurality of focal plane positions, and the relationship between the focal plane positions and the microlens array conforms to the following formula:
FTalbot＝(Q+M/N)2p2/λ
wherein, FTalbotIs the Talbot focal length, p is the pitch of the microlens array, and λ is the illumination wavelength. Q, M, N are all natural numbers, M < N.
It is understood that λ is the illumination wavelength, and the illumination source is generally selected from visible light having a wavelength of 400nm to 700nm, preferably 450mm, 520nm or 660 nm.
When p and λ are determined, the focal plane position is related to the natural number Q, M, N, and M, N, Q is selected depending on the configuration of the device. The Talbot spots illuminated onto the individual particles are first changed by adjusting M, N (e.g. the larger N the denser the Talbot lattice is when M is 1), and then the spacing between the microlens array and the next optical element is adjusted by changing Q, where FTalbotPreferably 100 mm. Further, p and FTalbotAfter determination of the ratio of (A), (B), FTalbotAnd thus the structure of the entire microlens array. With the preferred example p being 0.2mm, FTalbot100mm, and the ratio is 1:50 and less than 1: 15.
Therefore, by arranging the dodging unit 307 such that the image of the interference fringes formed on the flat panel 311 to be measured is schematically shown in fig. 4, the light intensity of each Talbot point can be expressed as:
ITalbot＝(1/n1)·∫IDS(xDS(θ))dθ＝(1/n1)·∫IDS(θ)dθ；
wherein n1 is the number of Talbot lattices. And when the distance d between two adjacent beams of the Talbot lattice is smaller than the size of the particle 312, the total light intensity received by the particle 312 on the detection surface 310 is IDS＝n2·ITalbotWhere n2 is the number of Talbot point-covering particles. Therefore, the scattered intensity of the final particle can be expressed as: i isresult＝(n2/n1)·∫η(xDS(θ))IDS(θ) d θ. Wherein the detection surface 310 is a focal surface of the dodging unit 307.
Because the integral term is the product of the scattering efficiency and the incident light intensity, the ratio of the influence of the high-frequency non-uniform term in the scattered Talbot lattice beam 313 and the 'oscillation' in the particle scattering curve is compressed, and the surface distribution has the 'uniform' influence on the particles at each position.
In addition, in another embodiment of the present invention, as shown in fig. 14, the light uniformizing unit 307 further includes: and a first shaping lens group 308, wherein the first shaping lens group 308 is positioned on a transmission path of the Talbot lattice beam 309 and is used for expanding or compressing the Talbot lattice beam 309.
It is understood that when the distance between two adjacent beams in the Talbot matrix beam 309 is larger than the size of the particle 312 on the focal plane 310 of the dodging unit 307 where the flat panel 311 to be measured is located, the first shaping lens group 308 compresses the Talbot matrix beam 309 so that the distance between two adjacent beams in the Talbot matrix beam 309 is smaller than the size of the particle 312. Wherein, in compression, the first shaping lens group 309 may be a converging lens (e.g., a convex lens).
When the distance between two adjacent beams in the talbot matrix beam 309 is smaller than the size of the particle 312 on the focal plane 310 of the dodging unit 307 where the flat plate 311 to be measured is located, but the whole distribution of the talbot matrix beam 309 is narrow, the talbot matrix beam 309 needs to be expanded to prevent the energy of the local light intensity irradiated to the particle 312 from being high and prevent the poor uniformity of the light distribution of the talbot matrix beam 309 irradiated to the particle 312. Wherein, the Talbot lattice light beam 309 after expanding still satisfies that the interval between two adjacent light beams is smaller than the size of the particle 312, so as to ensure that the light emitted from the plurality of micro-lenses in the dodging unit 307 can be overlapped on the particle 312, and the uniformity of the light distribution is maintained. Wherein, upon expanding the beam, the first shaping lens group 309 may be a diverging lens (e.g., a concave lens).
The imaging unit 316 will be described below.
Alternatively, as shown in fig. 3, 5 and 14, the imaging unit 316 includes a third shaping lens group 314 and a detector 315, the third shaping lens group 314 is used for collecting the light beam to be imaged 313; the detector 315 is configured to receive the light beam 313 to be imaged, and detect the foreign object 312 in the flat panel 311 to be detected according to the light beam 313 to be imaged.
The detector 315 may be a CCD or CMOS camera, among others.
The effects of the present invention will be described below by specific parameters and optical element settings. As shown in fig. 15, the flat panel particle size detecting apparatus includes: a light source unit 310, a first shaping lens group 308, a first microlens structure 3071, a second microlens structure 3072, and a second shaping lens group 305. The imaging unit 316 is not shown in fig. 15, and it is known that the imaging unit 316 is as described above and will not be described herein. In addition, the relative position between the light propagation direction and the panel to be measured in fig. 15 does not represent the real light propagation path.
For example, if a particle ball 312 with a diameter of 30 μm needs to be detected when the light source unit 301 emits a laser beam with a wavelength of 640nm, the microlens array may be configured such that the pitch p between the microlenses is 0.2mm and the focal length is 100 mm.
At this time, as shown in fig. 16, a spot having a surface distribution uniformity of more than 95% is to be formed on the detection surface 310, and as shown in fig. 17, a spot having an angular distribution uniformity of more than 90% is to be formed on the detection surface 310.
In addition, as shown in fig. 18, in the range of the direction angle from 0 degree to 180 degrees, the scattering efficiency (or relative scattering intensity) of the particles 312 with a diameter of 30 μm is distributed with the direction angle.
Taking the direction angle as 137 degrees as an example, it can be seen that, as shown in fig. 19, when the flat plate particle size detection apparatus 300 is configured to have an incident angle of 77 degrees and an acceptance angle of 60 degrees, since the two are located on both sides of the normal of the reticle plane (as shown in fig. 2), the actual included angle between the incident angle and the acceptance angle is 137 degrees, and at this time, the nominal values of the scattering efficiency of the particles 312 are 1.137E-8(S light) and 6.072E-9(P light).
As shown in fig. 20, when the configuration errors of the incident angle and the receiving angle are ± 1 degree, that is, the included angle between the incident angle and the scattering angle fluctuates between 135 degrees and 139 degrees, and the variation of the direction angle of the collimated light path, the maximum scattering efficiency and the minimum scattering efficiency of a single angle in the interval are different by about 2000 times (S) and 50 times (P), respectively.
In the case where no microlens array is added, the scattered energy distribution at each position of the field of view is as shown in fig. 21 within the error range of the arrangement of the flat panel particle size detection apparatus 300. It can be seen that even in the configuration where uniformity is ideal, the final particles have only 3.6% (S-light) and 68% (P-light) of the scattered energy.
When the flat-panel particle size detection apparatus 300 employs the microlens array group 307, since the angular distribution uniformity is controlled, the reception angle interval of each point can be increased, the weighted average value thereof is more balanced, and the scattered energy distribution at each position of the field of view is as shown in fig. 22, it can be seen that even in a configuration in which the uniformity is poor, the uniformity of the final scattered particles can be optimized to 97.9% (S light) and 94.0% (P light).
Therefore, according to the condition to be detected, the configuration of the micro-lens array group is determined, the Talbot dot matrix appears in the line light beam, the space between the Talbot dot matrixes is ensured to be smaller than the size of the particles, light with uniform angle and uniform surface can be obtained, and the particle size of the particles in the flat plate to be detected can be analyzed according to the final imaging in the imaging unit, so that the method is simpler and clearer.
In conclusion, according to the embodiment of the utility model provides a dull and stereotyped granularity check out test set for the detection light beam of light source unit outgoing forms the Talbot dot matrix light beam in the focal plane department of microlens array group, and the foreign matter scattering formation of Talbot dot matrix light beam in the flat board that awaits measuring treats the image forming light beam, and then, the foreign matter that the image forming unit was treated in the flat board of awaiting measuring according to treating the image forming light beam detects. The interval between two adjacent beams of light in the Talbot lattice light beams is smaller than the particle size of the foreign matter, so that the light irradiating any detected foreign matter is favorably overlapped by the light emitted by the micro lenses, the surface uniformity and the angle uniformity of the detection light beams incident to the flat plate to be detected are favorably ensured, wherein the angle uniformity can reach 90 percent, and the surface uniformity can reach 95 percent.
It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.
Claims (12)
1. A flat plate particle size detection apparatus, comprising:
a light source unit for emitting a detection beam;
the dodging unit at least comprises a micro-lens array group, the dodging unit is positioned on a transmission path of the detection light beam, and the detection light beam forms a Talbot lattice light beam at a focal plane of the dodging unit after passing through the dodging unit; the Talbot lattice light beam incident on the flat plate to be detected is scattered by foreign matters in the flat plate to be detected to form a light beam to be imaged; the light beam to be imaged carries the particle size information of the foreign matter; the distance between two adjacent beams in the Talbot lattice beams is smaller than the particle size of the foreign matter;
and the imaging unit is positioned on the transmission path of the light beam to be imaged and used for collecting the light beam to be imaged and detecting the foreign matters in the flat plate to be detected according to the light beam to be imaged.
2. The flat panel particle size detection apparatus of claim 1, wherein said light uniformizing unit further comprises: the first shaping lens group is positioned on a transmission path of the Talbot lattice light beam and is used for expanding or compressing the Talbot lattice light beam.
3. The flat panel particle size detection apparatus of claim 1, wherein said microlens array set includes two sets of microlens arrays, each said microlens array set including a plurality of microlenses arranged in an array; the number of microlenses in each set of the microlens array is greater than or equal to 20.
4. The flat panel particle size detection apparatus of claim 1, wherein said microlens array set includes two sets of microlens arrays, each said microlens array set including a plurality of microlenses arranged in an array; the distance between adjacent micro lenses in each group of micro lens array ranges from 0.2mm to 3 mm.
5. The flat panel particle size detection apparatus of claim 4, wherein a ratio of a spacing between adjacent microlenses in each set of said microlens array to a focal length of said microlens array is less than 1: 15.
6. The flat panel particle size detecting apparatus according to any of claims 3-5, wherein the microlens array set includes a first microlens array and a second microlens array; the first microlens array is located in a first microlens structure and the second microlens array is located in a second microlens structure;
the first microlens structure further comprises a first plane; the second microlens structure further comprises a second plane; the first microlens array, the first plane, the second plane, and the second microlens array are arranged in sequence along a transmission path of the detection beam.
7. The flat panel granularity detection apparatus of any one of claims 3 to 5, wherein the microlens array set comprises a third microlens array and a fourth microlens array, the third microlens array and the fourth microlens array both being located in a third microlens structure.
8. The flat panel particle size detecting apparatus of claim 1, wherein said light source unit comprises: the light source expansion assembly is positioned on the light emitting side of the point light source and used for expanding the point light beams emitted by the point light source to form line light beams.
9. The flat panel particle size detection apparatus of claim 8, wherein said point light source is a coherent light source.
10. The flat panel particle size detection apparatus of claim 8, wherein said light source expansion assembly comprises at least one of a cylindrical lens and a cylinder-like lens.
11. The flat panel particle size detection apparatus of claim 1, further comprising a second shaping lens group on a transmission path of said detection beam for collimating said detection beam.
12. The flat panel particle size detection apparatus of claim 1, wherein said imaging unit comprises a third shaping lens group and a detector, said third shaping lens group being configured to collect said light beam to be imaged; the detector is used for receiving the light beam to be imaged and detecting the foreign matter in the flat plate to be detected according to the light beam to be imaged.
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| CN202020301321.6U CN211718046U (en) | 2020-03-12 | 2020-03-12 | Dull and stereotyped granularity check out test set |
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| CN202020301321.6U CN211718046U (en) | 2020-03-12 | 2020-03-12 | Dull and stereotyped granularity check out test set |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112098425A (en) * | 2020-11-17 | 2020-12-18 | 北京领邦智能装备股份公司 | High-precision imaging system and method, image acquisition device and detection equipment |
| CN112630127A (en) * | 2021-03-10 | 2021-04-09 | 中国科学院上海高等研究院 | Vacuum particle counter |
| CN113218826A (en) * | 2021-05-24 | 2021-08-06 | 安徽工程大学 | Light path system of particle counter sensor |
| CN113218826B (en) * | 2021-05-24 | 2024-04-23 | 安徽工程大学 | Optical path system of particle counter sensor |
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2020
- 2020-03-12 CN CN202020301321.6U patent/CN211718046U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112098425A (en) * | 2020-11-17 | 2020-12-18 | 北京领邦智能装备股份公司 | High-precision imaging system and method, image acquisition device and detection equipment |
| CN112630127A (en) * | 2021-03-10 | 2021-04-09 | 中国科学院上海高等研究院 | Vacuum particle counter |
| CN113218826A (en) * | 2021-05-24 | 2021-08-06 | 安徽工程大学 | Light path system of particle counter sensor |
| CN113218826B (en) * | 2021-05-24 | 2024-04-23 | 安徽工程大学 | Optical path system of particle counter sensor |
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