CN117092876B - Extreme ultraviolet lithography mask plate defect detection system and method based on photon sieve - Google Patents
Extreme ultraviolet lithography mask plate defect detection system and method based on photon sieve Download PDFInfo
- Publication number
- CN117092876B CN117092876B CN202311333714.XA CN202311333714A CN117092876B CN 117092876 B CN117092876 B CN 117092876B CN 202311333714 A CN202311333714 A CN 202311333714A CN 117092876 B CN117092876 B CN 117092876B
- Authority
- CN
- China
- Prior art keywords
- extreme ultraviolet
- mask plate
- lithography mask
- photon sieve
- ultraviolet lithography
- 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.)
- Active
Links
- 238000001900 extreme ultraviolet lithography Methods 0.000 title claims abstract description 79
- 230000007547 defect Effects 0.000 title claims abstract description 43
- 238000001514 detection method Methods 0.000 title claims abstract description 29
- 238000000034 method Methods 0.000 title claims abstract description 17
- 238000003384 imaging method Methods 0.000 claims abstract description 34
- 230000001427 coherent effect Effects 0.000 claims abstract description 24
- 239000000523 sample Substances 0.000 claims description 28
- 230000004075 alteration Effects 0.000 claims description 15
- 230000003287 optical effect Effects 0.000 claims description 14
- 238000006073 displacement reaction Methods 0.000 claims description 11
- 238000005286 illumination Methods 0.000 claims description 11
- 238000004364 calculation method Methods 0.000 claims description 10
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 6
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 6
- 229910052750 molybdenum Inorganic materials 0.000 claims description 6
- 239000011733 molybdenum Substances 0.000 claims description 6
- 239000010703 silicon Substances 0.000 claims description 6
- 229910052710 silicon Inorganic materials 0.000 claims description 6
- 239000002131 composite material Substances 0.000 claims description 4
- 238000013461 design Methods 0.000 claims description 4
- 238000001914 filtration Methods 0.000 claims description 4
- 229910052754 neon Inorganic materials 0.000 claims description 3
- GKAOGPIIYCISHV-UHFFFAOYSA-N neon atom Chemical compound [Ne] GKAOGPIIYCISHV-UHFFFAOYSA-N 0.000 claims description 3
- 239000010410 layer Substances 0.000 description 12
- 238000004519 manufacturing process Methods 0.000 description 7
- 238000005516 engineering process Methods 0.000 description 6
- 238000012545 processing Methods 0.000 description 5
- 238000011161 development Methods 0.000 description 4
- 230000001105 regulatory effect Effects 0.000 description 4
- 239000000758 substrate Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 239000006096 absorbing agent Substances 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- 238000003475 lamination Methods 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- 230000010363 phase shift Effects 0.000 description 2
- 238000001259 photo etching Methods 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000000593 degrading effect Effects 0.000 description 1
- 238000000609 electron-beam lithography Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 238000001459 lithography Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000004377 microelectronic Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012634 optical imaging Methods 0.000 description 1
- 238000000059 patterning Methods 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 238000002834 transmittance Methods 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
- G03F1/00—Originals for photomechanical production of textured or patterned surfaces, e.g., masks, photo-masks, reticles; Mask blanks or pellicles therefor; Containers specially adapted therefor; Preparation thereof
- G03F1/22—Masks or mask blanks for imaging by radiation of 100nm or shorter wavelength, e.g. X-ray masks, extreme ultraviolet [EUV] masks; Preparation thereof
-
- 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
- G03F1/00—Originals for photomechanical production of textured or patterned surfaces, e.g., masks, photo-masks, reticles; Mask blanks or pellicles therefor; Containers specially adapted therefor; Preparation thereof
- G03F1/68—Preparation processes not covered by groups G03F1/20 - G03F1/50
- G03F1/72—Repair or correction of mask defects
-
- 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
- G03F1/00—Originals for photomechanical production of textured or patterned surfaces, e.g., masks, photo-masks, reticles; Mask blanks or pellicles therefor; Containers specially adapted therefor; Preparation thereof
- G03F1/68—Preparation processes not covered by groups G03F1/20 - G03F1/50
- G03F1/82—Auxiliary processes, e.g. cleaning or inspecting
- G03F1/84—Inspecting
-
- 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
- G03F7/20—Exposure; Apparatus therefor
- G03F7/2002—Exposure; Apparatus therefor with visible light or UV light, through an original having an opaque pattern on a transparent support, e.g. film printing, projection printing; by reflection of visible or UV light from an original such as a printed image
- G03F7/2004—Exposure; Apparatus therefor with visible light or UV light, through an original having an opaque pattern on a transparent support, e.g. film printing, projection printing; by reflection of visible or UV light from an original such as a printed image characterised by the use of a particular light source, e.g. fluorescent lamps or deep UV light
-
- 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
- G03F7/7065—Defects, e.g. optical inspection of patterned layer for defects
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
- Preparing Plates And Mask In Photomechanical Process (AREA)
Abstract
The invention discloses an extreme ultraviolet lithography mask plate defect detection system and method based on a photon sieve. And focusing the coherent extreme ultraviolet light on the extreme ultraviolet mask plate by adopting a photon sieve. And detecting extreme ultraviolet energy reflected by the extreme ultraviolet mask plate by adopting a detector, converting the detected energy into image information and storing the image information. And moving the extreme ultraviolet mask plate in the X direction and/or the Y direction to realize the scanning of the extreme ultraviolet mask plate pattern. And reconstructing the amplitude and phase information of the extreme ultraviolet mask plate image by adopting a laminated imaging algorithm to obtain higher resolution, and determining the defect type and position based on the reconstructed pattern. The invention uses the photon sieve to replace the traditional reflector and Fresnel zone plate, and realizes the imaging of the extreme ultraviolet mask plate in the extreme ultraviolet band, thereby detecting the defects on the mask.
Description
Technical Field
The invention relates to the field of microelectronic manufacturing and photoetching, in particular to an extreme ultraviolet photoetching mask plate defect detection system and method based on a photon sieve.
Background
The lithographic apparatus is the core equipment for integrated circuit fabrication, and its state of the art determines the degree of integration of the integrated circuit. Performance indexes such as resolution, overlay accuracy and the like of the lithography system determine the integration level of the integrated circuit. To achieve higher resolution, an effective solution is to reduce the wavelength used. Thus, the exposure wavelength of the lithographic apparatus continues to shorten from visible to ultraviolet, deep Ultraviolet (DUV), to Extreme Ultraviolet (EUV). The resolution of the extreme ultraviolet lithography machine with the exposure wavelength of 13.5nm and the numerical aperture of 0.33 reaches 13nm, and the extreme ultraviolet lithography technology is the next development direction of the integrated circuit and is already applied to the manufacture of 7nm technology node integrated circuits. However, one of the main bottlenecks in the development of the extreme ultraviolet lithography at present is the lack of imaging and detection technology of the mask plate to ensure the defect-free requirement of the extreme ultraviolet lithography mask plate. When patterning a wafer using a photomask, in order to previously recognize the influence of various defects formed in the photomask on the wafer, a researcher is required to design a specific inspection system to inspect the defects of the photomask.
As an important component of an imaging system, a mask type affects an important factor of the imaging quality of extreme ultraviolet light. Mask defects may occur during the manufacture of the euv mask, and even a small defect in the mask may cause serious defects in the circuit pattern on the wafer due to the progressive increase in complexity of the scanning process, significantly degrading the lithographic imaging quality. Accurate detection of the position, size, morphology, etc. of the extreme ultraviolet mask defects is an important means to ensure lithographic imaging quality. Defects of the extreme ultraviolet lithography mask are classified into amplitude type defects and phase type defects. The defects of the extreme ultraviolet lithography mask plate are obviously different under the detection light sources of different wave bands. The amplitude type defect detection requires that the wavelength of the detection light source is smaller than that of the defect, and the phase type defect detection requires that the wavelength band of the detection light source is extreme ultraviolet. Therefore, there is a need for an euv lithography reticle defect detection and imaging system with high resolution and imaging quality.
Conventional euv mask defect detection and imaging systems use lenses or euv mirrors and various techniques are required for the fabrication and installation of conventional catadioptric imaging elements. In addition, since the transmittance and reflectance of the catadioptric element are not 100%, the energy loss is serious in the case of using a plurality of element combinations, and thus a high energy power source is required. Therefore, the traditional extreme ultraviolet lithography mask plate defect detection and imaging system is high in processing difficulty and price, and needs a longer development period.
The conventional photodetector device can only record intensity information, and the loss of phase information is still a bottleneck for higher resolution, so that the phase and amplitude information of the sample pattern needs to be recovered at the same time to obtain higher resolution. The stacked imaging technology utilizes a coherent diffraction pattern, and the phase of a sample pattern is recovered through an iterative recovery algorithm and an effective constraint condition, so that a three-dimensional structure of the sample is obtained. This technique enables high resolution without the need for sophisticated and expensive imaging optics.
Disclosure of Invention
Aiming at the problems of high processing difficulty, long development period, high cost and insufficient resolution in the existing extreme ultraviolet lithography mask plate defect detection technology, the invention provides an extreme ultraviolet lithography mask plate defect detection system and method based on a photon sieve.
The aim of the invention is realized by the following technical scheme: the invention provides an extreme ultraviolet lithography mask plate defect detection system based on a photon sieve, which comprises an illumination optical system, the photon sieve, the extreme ultraviolet lithography mask plate, an aperture, a detector and a calculation module;
the illumination optical system comprises an extreme ultraviolet light source and an X-ray reflector, and the X-ray reflector reflects coherent extreme ultraviolet light emitted from the extreme ultraviolet light source towards the direction of the extreme ultraviolet lithography mask plate;
the photon sieve focuses coherent extreme ultraviolet light from the X-ray reflector and transmits the coherent extreme ultraviolet light to an extreme ultraviolet lithography mask plate;
the aperture is positioned between the photon sieve and the extreme ultraviolet lithography mask plate, and filters coherent extreme ultraviolet transmitted by the photon sieve;
the detector detects the extreme ultraviolet energy reflected by the extreme ultraviolet lithography mask plate, and moves the extreme ultraviolet lithography mask plate to realize the scanning of the extreme ultraviolet lithography mask plate pattern, and the detected energy is converted into image information;
and the calculation module utilizes a stacked imaging algorithm to reconstruct the amplitude and phase information of the extreme ultraviolet lithography mask plate based on image information, and determines the defect type and position based on the reconstructed pattern.
Further, the extreme ultraviolet light source comprises a laser and a gas cell, and a lens focusing a high-power femtosecond laser beam on the gas cell; the gas cell was filled with neon to optimize the generation efficiency of coherent extreme ultraviolet light having a wavelength of 13.5 nm.
Further, the X-ray mirror has a multilayer structure in which molybdenum layers and silicon layers are alternately arranged.
Further, the moving of the extreme ultraviolet lithography mask plate is achieved through a displacement platform, and the displacement platform moves in the X direction and/or the Y direction.
Further, the photon sieve is a high-freedom photon sieve, the diameter and the position of each light-transmitting micropore can be regulated and controlled, the limit of the same annular belt and the symmetrical design is removed, the chromatic aberration can be self-optimized, and meanwhile, the aberration of the X-ray reflecting mirror is compensated.
Further, the photon sieve is a compound photon sieve, diffraction focusing is realized by combining an annular belt and an aperture, diffraction efficiency is improved, the diameter and the position of each light-transmitting micropore can be regulated and controlled, chromatic aberration is self-optimized, and aberration of an X-ray reflecting mirror is compensated.
Further, the photon sieve is a three-dimensional photon sieve, the grey scale adjustment is carried out on the depth of each aperture, and the diameter and the position of the micropore are regulated and controlled to obtain an optimal structure.
Further, the stacked imaging algorithm specifically includes: the extreme ultraviolet light source irradiates a sample to be detected through focusing of a photon sieve, then the sample to be detected is received and recorded by the detector, the detection process is repeated for a plurality of times at different scanning positions, the areas between two adjacent scans are partially overlapped, lost phase information is reconstructed from the diffraction pattern by combining a reconstruction algorithm, and finally the pattern and the optical probe are reconstructed.
The invention also provides an extreme ultraviolet lithography mask plate defect detection method based on the photon sieve, which comprises the following steps:
(1) The extreme ultraviolet light source emits coherent extreme ultraviolet light, and the coherent extreme ultraviolet light is reflected towards the direction of the extreme ultraviolet lithography mask plate through the X-ray reflector;
(2) Focusing coherent extreme ultraviolet light from an X-ray reflector based on a photon sieve, filtering through an aperture, and transmitting the coherent extreme ultraviolet light to an extreme ultraviolet lithography mask plate;
(3) Detecting extreme ultraviolet energy reflected by an extreme ultraviolet lithography mask plate through a detector, and moving the extreme ultraviolet lithography mask plate to realize scanning of the extreme ultraviolet lithography mask plate pattern, and converting the detected energy into image information;
(4) And reconstructing amplitude and phase information of the extreme ultraviolet lithography mask plate based on image information by using a stack imaging algorithm, and determining the defect type and position based on the reconstructed pattern.
The beneficial effects of the invention are as follows:
1. the invention adopts a photon sieve focusing method, and replaces the traditional multi-lens focusing by utilizing the characteristics of small volume, easy processing, low cost and strong resolution of the photon sieve, thereby realizing the purposes of improving the efficiency, simplifying the structure, reducing the processing difficulty and the processing cost, reducing the system volume and improving the resolution.
2. The invention adopts photon sieve self-optimization to correct the chromatic aberration of the whole system, and improves the imaging quality of the system.
3. The invention adopts a laminated imaging algorithm, utilizes the detected diffraction pattern of the extreme ultraviolet lithography mask plate to realize the recovery of amplitude and phase information of the extreme ultraviolet lithography mask plate, and improves the defect detection accuracy of the extreme ultraviolet lithography mask plate.
4. The invention adopts electron beam lithography technology, can manufacture photon sieve with outer ring aperture of tens nanometers, even tens nanometers, and has great room for improving resolution compared with the traditional optical imaging lens.
Drawings
Fig. 1 is a schematic diagram of the overall structure of the present invention.
Fig. 2 is a schematic structural diagram of an euv lithography mask according to the present invention.
Fig. 3 is a schematic structural diagram of a photon sieve in accordance with the present invention.
FIG. 4 is a flowchart illustrating the operation of the system for detecting defects in an EUV lithography mask in accordance with the present invention.
In the figure, 101-an illumination optical system; 101A-an extreme ultraviolet light source; 101B-a lens; 101C-a gas cell; 102-an X-ray mirror; 103-photon sieve; 104-aperture; 105-extreme ultraviolet lithography mask; 105A-an absorber layer; 105b—a multilayer film reflective layer; 105c—low thermal expansion substrate; 106, a displacement platform; 107—a detector; 108-a calculation module.
Detailed Description
The invention will be described in further detail with reference to the drawings and the specific examples.
As shown in fig. 1, the system for detecting defects of an euv lithography mask based on a photon sieve provided by the invention comprises an illumination optical system 101, an X-ray mirror 102, a photon sieve 103, an aperture 104, an euv lithography mask 105, a displacement platform 106, a detector 107, a calculation module 108 and the like. The illumination optical system 101 includes an extreme ultraviolet light source 101A, a lens 101B, and a gas cell 101C, and can generate extreme ultraviolet light having a wavelength of 13.5 nm. The euv light source 101A may generate a high power femtosecond laser beam focused on the gas cell 101C through the lens 101B. The gas cell 101C is filled with neon to improve the generation efficiency of the extreme ultraviolet light having a wavelength of 13.5 nm. The reflective device X-ray mirror 102 is coated with a multilayer film to increase reflectivity, and for a 13.5nm wavelength, a molybdenum/silicon bilayer may be used, with a monolayer thickness of about 10nm and a total of about 70 layers. The X-ray reflector 102 reflects the extreme ultraviolet light generated by the illumination optical system into the photon sieve 103, and the photon sieve 103 focuses the extreme ultraviolet light from the X-ray reflector, so that the luminous flux of the system is increased, and the signal-to-noise ratio, imaging quality and resolution of the system are improved; and spatial filtering is carried out through an aperture 104 between the photon sieve and the extreme ultraviolet lithography mask plate, multi-stage diffraction light is filtered, and diffraction focusing is carried out on the extreme ultraviolet lithography mask plate 105. After the focused light beam is reflected from the euv lithography mask 105, the detector 107 detects the euv light energy reflected by the euv lithography mask 105, and the displacement platform 106 moves the euv lithography mask 105 in the X direction and/or the Y direction to scan the euv lithography mask pattern, so as to convert the detected energy into image information.
The calculation module 108 uses a stack imaging algorithm to reconstruct the amplitude and phase information of the euv lithography mask 105 based on the image information, and determines the defect type and position based on the reconstructed pattern.
According to the invention, the photon sieve 103 can realize a diffraction focusing function, and the chromatic aberration of the system can be corrected by adopting the high-freedom fractal photon sieve 103B on the basis of realizing the diffraction focusing function. The high-freedom photon sieve can regulate and control the diameter and the position of each light-transmitting micropore, relieve the limit of the same annular belt and symmetrical design, self-optimize chromatic aberration and compensate the aberration of the X-ray reflecting mirror. The photon sieve 103 can also adopt a composite photon sieve or a three-dimensional photon sieve; the composite photon sieve combines the annular belt and the aperture to realize diffraction focusing, improves diffraction efficiency, combines the characteristic of high-degree-of-freedom optimization, can regulate and control the diameter and the position of each light-transmitting micropore, self-optimizes chromatic aberration and compensates the aberration of the X-ray reflector; the three-dimensional photon sieve is used for carrying out grey adjustment on the depth of each aperture, and regulating and controlling the diameter and the position of the micropore to obtain an optimal structure.
As shown in FIG. 2, the diameter of the outer ring of the most basic amplitude type photon sieve 103A is about 16um, and the diameter of the focusing light spot is about 78nm. Wherein the circled portion represents light transmission. For a 13.5nm wavelength, the photonic sieve phase shift layer may be molybdenum, about 80nm thick, the substrate may be silicon, and about 100nm thick. The aperture stop 104 spatially filters the focused beam to avoid interference with higher order diffracted light. The high-degree-of-freedom fractal photon sieve 103B can be designed to expand the depth of focus and reduce the sensitivity of the diffraction element to wavelength to self-optimize chromatic aberration.
As shown in fig. 3, the euv lithography mask 105 includes an absorber layer 105A, a multilayer film reflective layer 105B, and a low thermal expansion substrate 105C. Wherein the absorption layer 105A is made of chromium, and the thickness is 70nm; the multilayer film reflecting layer 105B is a molybdenum/silicon multilayer film, the period P is 6.938nm, the thickness of each layer of molybdenum is 0.4 times of the period P, and the thickness of each layer of silicon is 0.6 times of the period P, and 40 periods are all provided; the low thermal expansion substrate 105C is microcrystalline glass with a size of 152.4mm by 6.35mm.
Lateral and longitudinal adjustment range of displacement platform 106: 140mm×140mm, resolution: 2 mu m, and the minimum scanning step is less than or equal to 0.2nm; the displacement platform 106 can be adjusted in axial direction position, facilitating fixed focus.
FIG. 4 is a flowchart illustrating the operation of an EUV lithography mask defect detection system according to an embodiment of the present invention, where the system operation is as follows: the extreme ultraviolet illumination system 101 emits an extreme ultraviolet beam, the extreme ultraviolet beam passes through the X-ray reflector 102, the photon sieve 103 and the aperture 104, the extreme ultraviolet beam is filtered and focused on the extreme ultraviolet lithography mask plate 105, the extreme ultraviolet lithography mask plate is reflected and received by the detector, the detector converts the light energy into digital information and stores the digital information, then the position of the mask plate is adjusted again by the displacement platform 106 for re-imaging until scanning is completed, and the image is transmitted to the calculation module 108 for image reconstruction.
The stack imaging algorithm in the calculation module of the invention comprises:
lamination imaging: scanning and irradiating different parts of the extreme ultraviolet lithography mask pattern by using the probe, repeatedly illuminating samples with a certain proportion of the front and back irradiation, recording diffraction intensity, performing iterative operation by means of constraint conditions (such as diffraction intensity constraint, overlapping scanning constraint and the like), reconstructing lost phase information from a large number of diffraction patterns, and finally reconstructing the samples and the optical probe.
Photon sieve imaging: the photon sieve is a novel diffraction optical element developed on the basis of the Fresnel zone plate, the bright and dark annular band of the Fresnel zone plate is replaced by a series of small holes distributed according to a certain rule, and the focusing light spot of the photon sieve is obviously smaller than that of the corresponding Fresnel zone plate, so that the photon sieve has stronger sidelobe suppression capability and can obviously improve the resolution. As a novel diffraction optical element, the photon sieve not only has the characteristic that the traditional diffraction optical element can image the ultra-short wavelength, but also can effectively inhibit higher-order diffraction and side lobes, and improve imaging quality. Even if the size of the photon sieve aperture is larger than the width of the corresponding fresnel zone plate zone, the imaging quality is not affected when the size of the photon sieve aperture does not exceed a certain range. The manufacturing difficulty of the photon sieve can be reduced, and the photon sieve is beneficial to increasing the luminous flux of the system.
Further, the idea and flow of extreme ultraviolet lamination imaging based on photon sieve are as follows: the extreme ultraviolet light source irradiates the extreme ultraviolet lithography mask plate through focusing of the photon sieve, and after a certain distance of propagation, the extreme ultraviolet light source is received by the detector and records the diffraction pattern. The detection process is repeated multiple times at different scanning positions, and the areas between two adjacent scans are partially overlapped. And combining a reconstruction algorithm to recover the amplitude of the object and the illumination probe.
Further, the extreme ultraviolet laminated imaging reconstruction algorithm based on the photon sieve obtains the information of the sample to be detected and the probe, firstly, the sample to be detected O and the probe P are initialized, then, iteration solution is started, and the iteration process specifically comprises the following steps:
1) Calculating emergent light corresponding to the jth scanning positionAnd calculates the transmitted distance +.>Post diffraction light->The amplitude and phase of the diffraction pattern of the detector plane are obtained, wherein,，/>representing spatial coordinates>Representing the secondary lightA source exit plane focused on the sample by a photon sieve, and transmitted to a detector plane for forward propagation>And->The corresponding probes and the sample to be tested are respectively +.>Representing the spatial displacement of the illuminated probe,representing the phase shift caused by the forward transmission;
2) Using diffraction spots obtained by corresponding detectionTo correct the diffraction pattern light field +.>In particular, i.e. to replace the amplitude, the phase is kept unchanged, wherein +.>Representing a first diffraction pattern spot;
3) Light field the diffraction patternReversely transmitting to the surface of the sample to be detected to obtain corrected emergent wave；
4) Separating the probe from the sample to be detected according to the extended stack imaging algorithm to obtain an updated sampleAnd probe->Is->，Wherein->Representing the iterative update coefficient of the information of the sample to be tested selected by oneself, < >>Information iterative update coefficient representing self-selected illumination probe, < ->Represents complex conjugate;
5) Sequentially changing scanning position) Repeating steps 1) to 4), completing one iteration process, reconstructing to obtain a final sample pattern and a probe pattern, and calculating the +.>Error of multiple iterations->Wherein->Representing the number of rows of the scan, +.>Representing the number of columns scanned>Representing a diffraction light field matrix;
6) Order theAnd the initial guess for this iteration is +.>And->；
7) Repeating iterative calculation processes 1) to 6) until the error functionThe required precision is met, and the iteration process is completed.
The invention provides an extreme ultraviolet lithography mask plate defect detection method based on a photon sieve, which comprises the following steps:
(1) The extreme ultraviolet light source emits coherent extreme ultraviolet light, and the coherent extreme ultraviolet light is reflected towards the direction of the extreme ultraviolet lithography mask plate through the X-ray reflector;
(2) Focusing coherent extreme ultraviolet light from an X-ray reflector based on a photon sieve, filtering through an aperture, and transmitting the coherent extreme ultraviolet light to an extreme ultraviolet lithography mask plate;
(3) Detecting extreme ultraviolet energy reflected by an extreme ultraviolet lithography mask plate through a detector, and moving the extreme ultraviolet lithography mask plate to realize scanning of the extreme ultraviolet lithography mask plate pattern, and converting the detected energy into image information;
(4) And reconstructing amplitude and phase information of the extreme ultraviolet lithography mask plate based on image information by using a stack imaging algorithm, and determining the defect type and position based on the reconstructed pattern.
The above-described embodiments are intended to illustrate the present invention, not to limit it, and any modifications and variations made thereto are within the spirit of the invention and the scope of the appended claims.
Claims (6)
1. The extreme ultraviolet lithography mask plate defect detection system based on the photon sieve is characterized by comprising an illumination optical system, the photon sieve, the extreme ultraviolet lithography mask plate, an aperture, a detector and a calculation module;
the illumination optical system comprises an extreme ultraviolet light source and an X-ray reflector, and the X-ray reflector reflects coherent extreme ultraviolet light emitted from the extreme ultraviolet light source towards the direction of the extreme ultraviolet lithography mask plate;
the photon sieve focuses coherent extreme ultraviolet light from the X-ray reflector and transmits the coherent extreme ultraviolet light to an extreme ultraviolet lithography mask plate;
the photon sieve is a high-freedom-degree photon sieve, a composite photon sieve or a three-dimensional photon sieve, the high-freedom-degree photon sieve can regulate and control the diameter and the position of each light-transmitting micropore, the limit of the same annular belt and the symmetrical design is removed, the chromatic aberration can be self-optimized, and meanwhile, the aberration of the X-ray reflecting mirror is compensated; the composite photon sieve combines the annular belt and the aperture to realize diffraction focusing, improves diffraction efficiency, can regulate and control the diameter and the position of each light-transmitting micropore, and self-optimizes chromatic aberration and compensates aberration of the X-ray reflector; the three-dimensional photon sieve can carry out gray adjustment on the depth of each aperture, regulate and control the diameter and the position of micropores to obtain an optimal structure;
the aperture is positioned between the photon sieve and the extreme ultraviolet lithography mask plate, and filters coherent extreme ultraviolet transmitted by the photon sieve;
the detector detects the extreme ultraviolet energy reflected by the extreme ultraviolet lithography mask plate, and moves the extreme ultraviolet lithography mask plate to realize the scanning of the extreme ultraviolet lithography mask plate pattern, and the detected energy is converted into image information;
and the calculation module utilizes a stacked imaging algorithm to reconstruct the amplitude and phase information of the extreme ultraviolet lithography mask plate based on image information, and determines the defect type and position based on the reconstructed pattern.
2. The photon sieve-based extreme ultraviolet lithography reticle defect detection system of claim 1, wherein the extreme ultraviolet light source comprises a laser and a gas cell and a lens focusing a high power femtosecond laser beam on the gas cell; the gas cell was filled with neon to optimize the generation efficiency of coherent extreme ultraviolet light having a wavelength of 13.5 nm.
3. The extreme ultraviolet lithography mask defect detection system based on the photon sieve according to claim 1, wherein the X-ray mirror has a multi-layer structure in which molybdenum layers and silicon layers are alternately arranged.
4. The system for detecting defects of an extreme ultraviolet lithography mask plate based on a photon sieve according to claim 1, wherein said moving said extreme ultraviolet lithography mask plate is performed by a displacement platform, said displacement platform moving in an X-direction and/or a Y-direction.
5. The extreme ultraviolet lithography mask plate defect detection system based on the photon sieve according to claim 1, wherein the stack imaging algorithm specifically comprises: the extreme ultraviolet light source irradiates a sample to be detected through focusing of a photon sieve, then the sample to be detected is received and recorded by the detector, the detection process is repeated for a plurality of times at different scanning positions, the areas between two adjacent scans are partially overlapped, lost phase information is reconstructed from the diffraction pattern by combining a reconstruction algorithm, and finally the pattern and the optical probe are reconstructed.
6. A method for detecting defects of an extreme ultraviolet lithography mask plate based on a photon sieve according to any one of claims 1 to 5, comprising the steps of:
(1) The extreme ultraviolet light source emits coherent extreme ultraviolet light, and the coherent extreme ultraviolet light is reflected towards the direction of the extreme ultraviolet lithography mask plate through the X-ray reflector;
(2) Focusing coherent extreme ultraviolet light from an X-ray reflector based on a photon sieve, filtering through an aperture, and transmitting the coherent extreme ultraviolet light to an extreme ultraviolet lithography mask plate;
(3) Detecting extreme ultraviolet energy reflected by an extreme ultraviolet lithography mask plate through a detector, and moving the extreme ultraviolet lithography mask plate to realize scanning of the extreme ultraviolet lithography mask plate pattern, and converting the detected energy into image information;
(4) And reconstructing amplitude and phase information of the extreme ultraviolet lithography mask plate based on image information by using a stack imaging algorithm, and determining the defect type and position based on the reconstructed pattern.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311333714.XA CN117092876B (en) | 2023-10-16 | 2023-10-16 | Extreme ultraviolet lithography mask plate defect detection system and method based on photon sieve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311333714.XA CN117092876B (en) | 2023-10-16 | 2023-10-16 | Extreme ultraviolet lithography mask plate defect detection system and method based on photon sieve |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN117092876A CN117092876A (en) | 2023-11-21 |
| CN117092876B true CN117092876B (en) | 2024-03-22 |
Family
ID=88780562
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311333714.XA Active CN117092876B (en) | 2023-10-16 | 2023-10-16 | Extreme ultraviolet lithography mask plate defect detection system and method based on photon sieve |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117092876B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB0913260D0 (en) * | 2009-07-30 | 2009-09-02 | Qinetiq Ltd | Coded aperture imaging |
| CN101561637A (en) * | 2009-05-15 | 2009-10-21 | 中国科学院光电技术研究所 | Laser direct-write photoetching system based on photon sieve |
| CN102289157A (en) * | 2011-08-16 | 2011-12-21 | 中国科学院微电子研究所 | Projection photoetching system with composite photon sieve |
| CN103365073A (en) * | 2012-04-10 | 2013-10-23 | 中国科学院微电子研究所 | Extreme ultraviolet lithographic mask defect detection system |
| CN103424985A (en) * | 2012-05-18 | 2013-12-04 | 中国科学院微电子研究所 | Defect detection system for extreme ultraviolet lithography mask |
| CN110297401A (en) * | 2019-06-28 | 2019-10-01 | 中国科学院上海光学精密机械研究所 | Extreme ultraviolet photolithographic mask multilayer film phase type defect inspection method |
| CN110398213A (en) * | 2019-07-23 | 2019-11-01 | 北京工业大学 | A kind of reflective lamination imaging method of continuous Terahertz |
| CN110658690A (en) * | 2018-06-28 | 2020-01-07 | 三星电子株式会社 | Apparatus and method for inspecting extreme ultraviolet mask and method for manufacturing extreme ultraviolet mask |
| CN112255776A (en) * | 2020-11-10 | 2021-01-22 | 四川欧瑞特光电科技有限公司 | Point light source scanning illumination method and detection device |
| WO2021127726A1 (en) * | 2019-12-23 | 2021-07-01 | Swinburne University Of Technology | Apparatus, system and method of digital imaging |
-
2023
- 2023-10-16 CN CN202311333714.XA patent/CN117092876B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101561637A (en) * | 2009-05-15 | 2009-10-21 | 中国科学院光电技术研究所 | Laser direct-write photoetching system based on photon sieve |
| GB0913260D0 (en) * | 2009-07-30 | 2009-09-02 | Qinetiq Ltd | Coded aperture imaging |
| CN102289157A (en) * | 2011-08-16 | 2011-12-21 | 中国科学院微电子研究所 | Projection photoetching system with composite photon sieve |
| CN103365073A (en) * | 2012-04-10 | 2013-10-23 | 中国科学院微电子研究所 | Extreme ultraviolet lithographic mask defect detection system |
| CN103424985A (en) * | 2012-05-18 | 2013-12-04 | 中国科学院微电子研究所 | Defect detection system for extreme ultraviolet lithography mask |
| CN110658690A (en) * | 2018-06-28 | 2020-01-07 | 三星电子株式会社 | Apparatus and method for inspecting extreme ultraviolet mask and method for manufacturing extreme ultraviolet mask |
| CN110297401A (en) * | 2019-06-28 | 2019-10-01 | 中国科学院上海光学精密机械研究所 | Extreme ultraviolet photolithographic mask multilayer film phase type defect inspection method |
| CN110398213A (en) * | 2019-07-23 | 2019-11-01 | 北京工业大学 | A kind of reflective lamination imaging method of continuous Terahertz |
| WO2021127726A1 (en) * | 2019-12-23 | 2021-07-01 | Swinburne University Of Technology | Apparatus, system and method of digital imaging |
| CN112255776A (en) * | 2020-11-10 | 2021-01-22 | 四川欧瑞特光电科技有限公司 | Point light source scanning illumination method and detection device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN117092876A (en) | 2023-11-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR102013083B1 (en) | Apparatus for euv imaging and methods of using same | |
| US7821714B1 (en) | Apparatus and method for measuring aerial image of EUV mask | |
| KR102100001B1 (en) | Wave front aberration metrology of optics of euv mask inspection system | |
| TWI528116B (en) | Method of forming a spectral purity filter | |
| KR100541487B1 (en) | Adjustment method and apparatus of optical system, and exposure apparatus | |
| TW200841003A (en) | Measurement apparatus, exposure apparatus, and semiconductor device fabrication method | |
| US7543948B2 (en) | Multilayer mirror manufacturing method, optical system manufacturing method, exposure apparatus, and device manufacturing method | |
| CN114002191A (en) | Photoetching defect detection device | |
| KR101690373B1 (en) | A method of fabricating an integrated circuit with enhanced defect repairability | |
| CN117092876B (en) | Extreme ultraviolet lithography mask plate defect detection system and method based on photon sieve | |
| US8049897B2 (en) | Reticle defect inspection apparatus and inspection method using thereof | |
| CN113494966A (en) | Apparatus and method for measuring phase of EUV mask and method for manufacturing mask | |
| KR102239730B1 (en) | Pattern Defect Inspection Apparatus for Reflective Extreme Ultraviolet Mask with Scanning Type | |
| US8637840B2 (en) | EUV projection lens and optic system having the same | |
| KR20040026094A (en) | Lithographic apparatus and device manufacturing method | |
| JP7203453B1 (en) | Wafer Defect Improvement Method by EUV Blank Mask Defect Detection | |
| JP3958261B2 (en) | Optical system adjustment method | |
| JP2000097620A (en) | Interferometer | |
| JP2017187547A (en) | EUV mask inspection apparatus and focus adjustment method | |
| US11619876B1 (en) | System of inspecting pattern defect in scanning-type reflective extreme ultraviolet mask | |
| KR102591666B1 (en) | Scanning Type EUV mask pattern image measuring device | |
| KR20230088459A (en) | Binary intensity mask for the EUV spectral range | |
| CN118244573A (en) | EUV mask defect detection device and system | |
| CN118033984A (en) | Overlay correction method, exposure method, and semiconductor device manufacturing method | |
| JP2002267799A (en) | Multilayer film reflector and regeneration method of multilayer film reflector |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |