Source: https://patents.google.com/patent/CN107463065A/en
Timestamp: 2020-02-24 09:53:58
Document Index: 787216029

Matched Legal Cases: ['art 212', 'art 212', 'art 212', 'art 212', 'art 212', 'art 212', 'art 1002', 'art 1004', 'art 1002', 'art 1004', 'art 1002', 'art 1002', 'art 1004', 'art 1002', 'art 1004', 'art 1002', 'art 1004', 'art 222', 'art 222', 'art 222', 'art 222']

CN107463065A - method for repairing mask - Google Patents
method for repairing mask Download PDF
CN107463065A
CN107463065A CN201710358246.XA CN201710358246A CN107463065A CN 107463065 A CN107463065 A CN 107463065A CN 201710358246 A CN201710358246 A CN 201710358246A CN 107463065 A CN107463065 A CN 107463065A
CN201710358246.XA
游信胜
严涛南
秦圣基
2016-06-06 Priority to US62/346,273 priority
2016-09-01 Priority to US15/254,607 priority
2017-05-19 Application filed by 台湾积体电路制造股份有限公司 filed Critical 台湾积体电路制造股份有限公司
2017-12-12 Publication of CN107463065A publication Critical patent/CN107463065A/en
The embodiment provides a kind of method for repairing mask, including check the defects of mask is with the defects of location mask region.Obtain the phase distribution of the aerial image of defect area.Determine the point spread function of imaging system.The phase distribution of aerial image based on defect area and point spread function confirm one or more restoring areas of mask.Renovation technique is performed to form one or more remanufactured components to one or more restoring areas of mask.
Method for repairing mask
Embodiments of the invention are related to semiconductor applications, the method for more particularly relating to repair mask.
In semiconductor integrated circuit (IC) industry, the technological progress of IC materials and design is generated more for IC, wherein, often A generation all has circuit smaller than first prior-generation and more complicated.In IC evolution processes, functional density (that is, unit chip face The quantity of interconnection devices in product) generally increasing, while physical dimension (that is, the minimal modules that manufacturing process can be used to create (or line)) reduce.This scale down technique generally provides many benefits by increasing yield efficiency and reducing relevant cost. Such scale down also increases processing and manufacture IC complexity.
For example, implement the demand growth of the photoetching process of higher resolution.For handling a kind of photoetching skill of this demand Art is deep ultraviolet lithography (EUVL).New challenge be present in the mask used in EUVL.For example, used in far ultraviolet (EUV) mask Sandwich construction.Microcosmic non-flatness (for example, being caused by defect) on the surface of the substrate of EUV mask can make to be subsequently deposited at The film deformation of sandwich construction above, this can influence the quality or integrality of the image of corresponding exposure.However, it can not pass through Standard repair techniques are removed below the multilayer of EUV mask or the defects of inner side.
Accordingly, it is desired to provide improved mask restorative procedure.
The embodiment provides a kind of method for repairing mask, methods described includes：Check mask to position The defects of the defects of stating mask region；The phase distribution of the aerial image of the defect area is obtained in imaging systems；It is determined that The point spread function of the imaging system；The phase distribution of aerial image based on the defect area and the point spread function To confirm one or more restoring areas of the mask；And reparation is performed to one or more restoring areas of the mask Technique is to form one or more remanufactured components.
Embodiments of the invention additionally provide a kind of method for repairing mask, including：Receive the far ultraviolet (EUV) of patterning Mask, the extreme ultraviolet mask of the patterning include the absorption region with absorbing material, define the reflector space of master unit with And defect；It is determined that region as caused by the defect and the defects of invading the reflector space；Obtain the defect area The phase distribution of image；The point spread function of imaging system is provided；According to the point spread function and the figure of the defect area The phase distribution of picture determines the restoring area in the absorption region；And remove the reparation area using mask repair tool The absorbing material in domain is to form remanufactured component.
Embodiments of the invention additionally provide a kind of method for repairing mask, including：Reception includes printing unit and defect Mask；Check the defects of mask is to position defect region；Determine the point spread function of imaging system；Based on described Point spread function and the defect area confirm the restoring area of the mask；Using mask repair tool to the mask Restoring area performs renovation technique to form remanufactured component；The mask is exposed to radiation in the imaging system with from institute Printing unit is stated to produce the first radiation and produce the second radiation from the remanufactured component；And radiated using described first and institute The photoresist for stating the second radiation to give away one's position.
When reading in conjunction with the accompanying drawings, it is better understood the present invention from described in detail below.It is emphasized that root According to the standard practices of industry, all parts are not drawn on scale, and are for illustration purposes only.In fact, in order to clearly beg for By the size of all parts arbitrarily can increase or reduce.
Figure 1A, Figure 1B and Fig. 1 C are the stream for being used to repair the method for mask according to one or more embodiments of the invention Cheng Tu.
Fig. 2A is the top view according to photomask (or reticle mask or mask) part for some embodiments.Fig. 2 B are roots According to the sectional view of Fig. 2A of some embodiments mask.Fig. 2 C (or reticle mask or are covered according to the photomasks of some embodiments Mould) part top view.
Fig. 3 A and Fig. 3 B are the sectional views of the exemplary deficiencies in the reflection mask according to each embodiment.
Fig. 4 shows a part for the photomask according to one embodiment.
Fig. 5 A show a part for the photomask according to one embodiment.Fig. 5 B show according to some embodiments into As system.
Fig. 6 A show the imaging system according to some embodiments.Fig. 6 B show according to Fig. 6 A of some embodiments into As the point spread function (point spread function) of system.Fig. 6 C show the point spread function according to some embodiments Several two-dimensional projections.
Fig. 7 A show two of the mask through the point spread function in imaging system according to some embodiments The amplitude distribution of the light of punctual openings (point opening) transmission.Fig. 7 B are shown passes through basis according to some embodiments The amplitude distribution of the light of a transmission in Fig. 7 A of point spread function in imaging system two punctual openings.
Fig. 8 A show two of the mask through the point spread function in imaging system according to some embodiments The amplitude distribution of the light of punctual openings transmission.Fig. 8 B show expanding through the point in imaging system according to some embodiments Dissipate the amplitude distribution of the light of a transmission in Fig. 8 A of function two punctual openings.
Fig. 9 A show two of the mask through the point spread function in imaging system according to some embodiments The amplitude distribution of the light of punctual openings transmission.Fig. 9 B show expanding through the point in imaging system according to some embodiments Dissipate the amplitude distribution of the light of a transmission in Fig. 9 A of function two punctual openings.
Figure 10 is the schematic top view according to a part for the mask represented by pixel of some embodiments.
Figure 11 is regarded according to the schematic top of a part for the mask for wherein determining initial restoring area of some embodiments Figure.
Figure 12 is the schematic top view according to a part for the mask including restoring area of some embodiments.
Figure 13 is the schematic top view according to a part for the mask including restoring area of some embodiments.
Figure 14 is the schematic top view according to a part for the mask of the reparation including remanufactured component of some embodiments.
Figure 15 A are the top views according to a mask part for some embodiments.Figure 15 B are the figures according to some embodiments The sectional view of a part for 15A mask.The amplitude in the defects of Figure 15 C are the masks according to Figure 15 A of some embodiments region Distribution.The intensity distribution in the defects of Figure 15 D are the masks according to Figure 15 A of some embodiments region.
Figure 16 A be according to some embodiments formed remanufactured component after Figure 15 A mask a part top view. Figure 16 B are the sectional views according to a part for Figure 16 A of some embodiments mask.Figure 16 C are the figures according to some embodiments The defects of 16A mask region amplitude distribution.The defects of Figure 16 D are the masks according to Figure 14 of some embodiments region Intensity distribution.
Figure 17 A are the top views according to a mask part for some embodiments.Figure 17 B are the figures according to some embodiments The sectional view of a part for 17A mask.The amplitude in the defects of Figure 17 C are the masks according to Figure 17 A of some embodiments region Distribution.The intensity distribution in the defects of Figure 17 D are the masks according to Figure 17 A of some embodiments region.
Figure 18 A be according to some embodiments formed remanufactured component after Figure 17 A mask a part top view. Figure 18 B are the sectional views according to a part for Figure 17 A of some embodiments mask.Figure 18 C are the figures according to some embodiments The defects of 18A mask region amplitude distribution.The defects of Figure 18 D are the masks according to Figure 18 A of some embodiments region Intensity distribution.
Disclosure below provides a variety of different embodiments or example, to realize the different characteristic of the present invention.Below will The instantiation for describing component and arrangement is of the invention to simplify.Certainly, these are only example and are not intended to limit the present invention.Example Such as, in the following description, above second component or it is upper formation first component can include first component and second component it is direct The embodiment of contact, it can also include being formed additional component between first component and second component and cause first component and the The embodiment that two parts are not directly contacted with.Moreover, the present invention in various embodiments can be with repeat reference numerals and/or letter.This Kind is repeated merely to concise and clear, and its own is not offered as the relation between each embodiment discussed and/or configuration.
It should be noted that embodiments of the invention can make including but not limited to integrated circuit (IC) manufacture, fabrication mask and The various semiconductor fabrication process of mask reparation obtain benefit.
Figure 1A is to repair lacking in the mask built according to each embodiment of the present invention in one or more embodiments The flow chart of sunken method 100.Can in the mask retail shop for manufacturing mask, for being manufactured using mask on wafer Implement mask reparation in the factory of semiconductor devices or in the glass works for manufacturing mask blanket.It should be understood that in method Extra step can be provided before and after, during 100, and for the extra embodiment of method 100, can substitute, Deletion or some mobile steps.Method 100 is only example, and is not intended to the limitation present invention and is clearly enumerated in claim Those.
Method 100 starts from frame 102, receives or provide tool defective mask.During photoetching process, mask is used for Device and/or circuit are manufactured on semiconductor crystal wafer.Mask includes substrate and is formed on substrate or will be formed on substrate Pattern.Pattern is defined according to circuit design.
With reference to figure 2A and Fig. 2 B example, and in the embodiment of frame 102, EUV lithography system will be used for by showing In reflection mask 200 (also referred to as EUV mask 200).Reflection mask 200 includes substrate 202, deposition on the substrate 202 anti- Penetrate multilayer (ML) 204, the coating 206 being deposited on reflection ML 204 (also referred to as cushion 206) and be deposited on covering The absorbed layer 220 of patterning on layer 206.It should be understood that without departing from the scope of the invention, in mask 200 The other configurations and inclusion of each entry or omission are all possible.
In certain embodiments, substrate 202 can include low thermal expansion material (LTEM).Substrate 202 is used to make due to logical The image fault caused by the lighting radiation heating mask strengthened is crossed to minimize.LTEM can include fused silica, tekite English, calcirm-fluoride (CaF2), carborundum, silica-oxidation titanium alloy and/or other suitable LTEM known in the art.Substrate 202 include the material with low defect grade and smooth surface.
Reflection ML 204 is deposited on the substrate 202.According to Fresnel equatioies, light is propagated across with different refractions Light reflection can occur during interface between two kinds of materials of rate.When the difference of refractive index is bigger, reflected light is also more.In order to Strengthen reflected light, a kind of method can also increase the quantity at interface by depositing the reflection ML 204 of alternative materials, and lead to Cross and select each layer of suitable thickness in reflection ML 204 to make the light constructive interference reflected from different interfaces.It is however, anti- The absorption for penetrating material used in ML 204 limits the highest reflectivity that can reach.Reflection ML 204 includes multiple films Right, such as molybdenum-silicon (Mo/Si) film is to (e.g., molybdenum layer is located at silicon layer above and below in each film pair).Alternatively, Reflection ML 204 can include molybdenum-beryllium (Mo/Be) film pair, or have at the EUV wavelength that can be used for reflecting ML 204 Any material of high reflectivity.Reflection ML 204 each layer of thickness all relies on EUV wavelength and incidence angle.Regulation reflection ML 204 thickness, with the maximum constructive interference of EUV light reflected by reflecting ML 204 to realize at each interface and right The minimal absorption of EUV light.Reflection ML 204 may be selected such that it provides the high reflection to emission types/wavelength of selection Rate.The typical amounts of film pair are between 20 to 80, but any amount of film is to being all possible.In some realities Apply in example, reflection ML 204 includes 40 pairs of Mo/Si layers.In an example, each Mo/Si film is to having about 7nm Thickness, gross thickness 280nm, and be achieved in about 70% reflectivity.
Coating 206 is deposited on reflection ML 204.Because coating 206 has the etching characteristic different from absorbed layer, All coatings 206 are used as etching stopping layer in the subsequent patterning or renovation technique of absorbed layer, will be described afterwards. Coating 206 includes ruthenium (Ru) or such as Ru compounds of ruthenium-boron (RuB) or ruthenium-silicon (RuSi).
Absorbed layer 220 is deposited on coating 206, and is then patterned according to ic design layout to form master unit 222 (also referred to as reflector space 222 or printing units 222).In certain embodiments, absorbed layer 220 absorbs and is incident upon thereon Radiation beam.Absorbed layer 220 can include single or multiple lift.Absorbed layer 220 can include the suction selected from the group of following material Receive material：Chromium (Cr), chromium oxide (CrO), titanium nitride (TiN), tantalum nitride (TaN), tantalum (Ta), titanium (Ti) or aluminium-copper (Al- Cu), palladium, boron carbide tantalum (TaBN), aluminum oxide (AlO), molybdenum (Mo), other suitable materials and combinations thereof.
When incident EUV-radiation is incident upon in EUV mask 200, the absorption EUV-radiation of absorbed layer 220 of patterning, and ML 204 reflection EUV-radiations, so as to form the EUV-radiation of patterning, this can be used for patterned substrate.As shown in Figure 2 B, EUV is covered Mould 200 includes the 220 corresponding absorption region of absorbed layer with patterning.EUV mask 200 includes corresponding with exposed ML 204 Master pattern 222.
In certain embodiments, reflecting the defects of ML can change or Writhing reflex in direction, shape or phase Beam.Therefore, the quality of the image (e.g., on the substrate of resist coating) of corresponding exposure or integrality are by positioned at reflection The defects of the reflection ML 204 of EUV mask 200 influence.In certain embodiments, lacking in the reflection ML of EUV mask is reflected Fall into the phase for the beam for influenceing reflection, and also referred to as phase defects.In the example shown in fig. 2b, the beam 214a of input from ML 204 is reflected to form the beam 214b of reflection.Particle 211 near ML 204 low portion can cause reflection Phase shift and/or changes in amplitude in beam 214b, and introduce error being transferred to using EUV mask 200 in the pattern of substrate.Bag The area (area for e.g., reflecting EUV mask 200) for including such as deformation caused by particle 211 is properly termed as defect area 212.Such as In some examples shown in Fig. 2A and Fig. 2 B, whole defect area 212 is located in reflector space 222 or lower section.In other words, exist As that shown in fig. 2 c in some examples, the part 212a of defect area 212 is located in reflector space 222 or lower section, and defect Another part 212b in region 212 is located in absorbed layer 220 or lower section.
With reference to figure 1A, method 100 is carried out to frame 104, wherein, use such as optical inspection tools or AFM (AFM) mask inspection tool checks the defects of mask is to confirm defect region.In certain embodiments, check that mask includes Scan the surface of mask and position, shape and/or the size in the defects of mask region are provided.In certain embodiments, exist In frame 104, the surface profile of defect area is generated.In certain embodiments, formed on mask after ML 204, but in shape Inspection is performed before into coating 206 and the absorbed layer 220 of deposition and pattern mask.In certain embodiments, in shape Into after coating 206, but deposited on mask and perform inspection before patterning absorbed layer 220.In some embodiments In, deposit and pattern on mask and perform inspection after absorbed layer 220.
With reference to figure 2C example, in certain embodiments, frame 104 includes removing the optional step of the absorbed layer in defect area Suddenly.In Fig. 2 C example, defect area 212 includes the part 212b in the absorbed layer 220 of EUV mask 200.In such reality In example, a part for the absorbed layer 220 in 212b area can be removed and (e.g., pass through mask repair tool), so that covering Layer 206 is exposed in whole defect area 212 (including part 212a and 212b).Alternatively, in certain embodiments, do not remove Absorbed layer 220 in defect area part 212b area, and the coating 206 in defect area part 212a area is not yet Exposure.
With reference to figure 1A, method 100 is carried out to frame 106, wherein it is determined that the phase and amplitude of the aerial image of defect area point Cloth.Above with reference to as described in Fig. 2A and Fig. 2 B, the defects of mask can be to the Shu Zaocheng distortions of the reflection from defect area (e.g., to phase and/or amplitude), this causes exposure image corresponding to the distortion in intensity of the aerial image of defect area and influence Quality or integrality.Each embodiment of frame 106 is determined for the phase and amplitude point of the aerial image of defect area Cloth, such as including the method 106B shown in method 106A and Fig. 1 C shown in Figure 1B.
With reference to figure 1B, Fig. 3 A, Fig. 3 B and Fig. 4, in certain embodiments, opened in frame 106, method 106A passes through for determination The aerial image in the defects of deformation data of each layer (e.g., ML 204, coating 206) of mask 200 is built region is (e.g., burnt The aerial image of plane) phase and amplitude distortion.Method 106A starts from frame 120, wherein providing the surface wheel of defect area 212 It is wide.For example, covering by using such as optical inspection tools, AFM (AFM) and PSTM (STM) Mould checking tool generates the surface of defect area wheel in the opening position of defect area 212 and/or the surface of neighbouring scanning mask It is wide.In some instances, generated using identical technique (e.g., AFM techniques) at frame 104 surface profile of defect area with Determine defect area.In some instances, come using the inspection technique different from the technique of the frame 104 for determining defect area Generate the surface profile of defect area.With reference to figure 3A, in some instances, determining the surface profile 302 of defect area 212 includes Projection and there is width W1 and height T1.With reference to figure 3B, in some instances, the surface profile 302 of defect area 212 is determined Including depression, and surface profile 304 has depth T2 and width W2.
With reference to figure 1B and Fig. 4, method 106A is carried out to frame 122, wherein, the surface profile next life based on defect area 212 Into the deformation data of the layer of mask.In the example in figure 4, region 212 includes surface profile 302, and base the defects of mask 200 The deformation data of the layer of mask 200 is generated in surface profile 302.The ML 204 of mask 200 includes film to 204-1,204- 2nd ... and 204-N, wherein N be positive integer (e.g., about 40).In certain embodiments, deformation data 408 includes substrate 202 substrate surface profile 404 and N number of film to surface profile 406-1,406-2 ..., 406-i ... and 406- N.Those surface profiles correspond between film to 204-1,204-2 ... and interface between 204-N and between film To the interface between 204-N and coating 206.In certain embodiments, deformation data 408 includes height H0、...、Hi、...、 And HN.Height H0It is the height of particle 211, and height H1、Hi... and HNIt is film to surface profile 406- 1st ..., 406-N and horizontal plane film to 204-1,204-2 ... and the difference between 204-N.In certain embodiments, Deformation data 408 uniquely describes the structure of the layer of the lower section of defect area 212.
In various embodiments, can use based on for forming the deposition of mask 200 and certain order of etching step The computer simulation of sedimentation model and etching model generate deformation data 408.Sedimentation model and etching model include deposition And etching parameter, such as include the growth parameter(s) of deposition step (deposition step of each for forming film pair and coating) (e.g., the thickness of each of the quantity of film pair, film pair) and etching step are (e.g., for removing in reflector space 222 The etching step of absorbed layer) etching parameter (e.g., rate of etch).
With reference to figure 1B, frame 106 is carried out to frame 124, wherein it is determined that the phase and/or amplitude of the aerial image of defect area Distribution.In some instances, the simulation of the optical diffraction of the deformation data of the layer based on mask 200 is performed, to determine defect area Aerial image phase and/or amplitude distribution.Optical condition (e.g., the wavelength of radiation source, the number of imaging system can also be used Value aperture) simulation is performed, wherein, mask 200 is used to its pattern being transferred to target substrate.
With reference to figure 1C, Fig. 5 A and Fig. 5 B, alternatively, in certain embodiments, method 106B is used at frame 106 using scarce Defocus (through-focus) intensity distribution for falling into region determines aerial image (e.g., the aerial shadow in focal plane of defect area Picture) phase and/or amplitude distribution.In some instances, surface profiles of the method 106B independent of defect area 212.Such as Shown in Fig. 5 A example, in certain embodiments, with ML 204 the top surface farther away from ML 204 film to compared with, The film of ML 204 top surface closer to ML 204 is to that can have less deformation.In such embodiments, based on scarce It is challenging to fall into the deformation data of the layer of the surface profile generation mask in region 212, wherein, region 212 has the defects of Fig. 5 A There is the surface profile more flat than the surface profile shown in Fig. 4.Because surfaces of the method 106B independent of defect area 212 Profile, so both regions 212 the defects of region the defects of method 106B can be used for Fig. 5 A 212 and Fig. 4.
Method 106B starts from frame 130, wherein, the focal plane intensity distribution of the aerial image of acquisition defect area 212.Ginseng Fig. 5 B are examined, show the example of the schematic diagram of the simplification of imaging system 500.Imaging system 500 can be used on mask 200 Pattern is transferred to target (e.g., wafer).Imaging system 500 has pupil plane 502 and focal plane 504.For example, can be by using The actinicity checking tool configured according to the optical condition (e.g., wavelength, numerical aperture, image plane distance) of imaging system 500 Or microlithography simulation microscope divides to obtain the focal plane intensity of the aerial image in region 212 the defects of at focal plane 504 Cloth.
Then method 106B is carried out to frame 132, wherein, obtain one of aerial image of region the defects of at out-of-focus plane Or multiple out-of-focus plane intensity distributions.With reference to figure 5B example, out-of-focus plane 506 be located at pupil plane 502 and focal plane 504 it Between, and with the distance Z1 apart from focal plane 504 (e.g., between about 40 μm to about 50 μm).Measure at out-of-focus plane 506 The defects of region 212 aerial image the first out-of-focus plane intensity distribution.Similarly, out-of-focus plane 508 is arranged on distance and dissipated Distance Z2 (e.g., between about 20 μm and about 25 μm) place of focal plane 504, and obtain area the defects of at out-of-focus plane 508 Second out-of-focus plane intensity distribution of the aerial image in domain.Can by using according to the optical condition of imaging system 500 (e.g., Wavelength, numerical aperture, image plane distance) configuration actinicity checking tool or microlithography simulation microscope obtain Intensity distribution.
Then, method 106B is carried out to frame 134, wherein, use the focal plane intensity distribution and out-of-focus plane of defect area Intensity distribution is distributed to rebuild the phase and amplitude of the image focal plane of defect area.For example, the Gai Shibei such as changed The various algorithms of Ge-Sa Ke stone algorithms can be used for rebuilding.
With reference to figure 1A, Fig. 6 A, Fig. 6 B and Fig. 6 C, then, method 100 is carried out to frame 108, wherein, receive imaging system Optical parametric is to determine the point spread function of imaging system.In various embodiments, can based on imaging system type determine The point spread function of imaging system.In certain embodiments, imaging system is coherence imaging system, and its radiation source is that have The point source of infinite small size.The complex amplitude (including phase and amplitude) of light field on the wafer of this coherence imaging system is phase The point spread function of dry imaging system and the convolution of corresponding mask pattern.The point spread function of coherence imaging system can be used Optical field distribution on the wafer of the punctual openings on mask in coherence imaging system.Wafer in this coherence imaging system On light field intensity be light field complex amplitude mould square.In certain embodiments, imaging system be partially coherent into As system, and its radiation source is extended source.The light field for being not easy to define on the wafer of this partially coherent image formation system is answered Conjunction amplitude.In order to calculate the intensity of the light field on wafer, the transmission interaction coefficent of this partially coherent image formation system can be performed Singular value decomposition to obtain characteristic function and corresponding characteristic value.The light field on wafer in this partially coherent image formation system Intensity be the mould that corresponding characteristic function is multiplied by corresponding characteristic value with the convolution of mask pattern quadratic sum.In this implementation In example, the characteristic function with eigenvalue of maximum may be used as point spread function in the mask repair process that is discussed below, and And it is properly termed as the point spread function of partially coherent image formation system.
With reference to figure 6A example, imaging system 600 illustrated therein is.Imaging system 600 can be with begging for above with reference to Fig. 5 B The imaging system 500 of opinion is identical.In certain embodiments, imaging system 600 can include EUV imaging systems.Imaging system 600 can receive mask 200 and substrate 612, perform photoetching process to substrate 612 using mask 200 and generate the lining of imaging Bottom.Imaging system 600 includes multiple subsystems, such as radiation source 602, luminaire 604, the mask for being configured to receive mask 200 Platform 606, projection optics 608 and the substrate table 610 for being configured to receive Semiconductor substrate 612.Imaging system 600 exposes The photosensitive material (e.g., photoresist layer) coated in the Semiconductor substrate 612 of such as Silicon Wafer.The IC defined on mask 200 is set Meter pattern is imaged to photoresist layer to form potential pattern.Semiconductor substrate 612 can be any suitable elemental semiconductor, Compound semiconductor or alloy semiconductor.In certain embodiments, handled using the additional step such as developed and bakeed sudden and violent The substrate 612 of dew on substrate to create pattern.For example, the patterning of photoresist layer can also include the photoresist of development exposure Layer has the photoresist layer of one or more patternings being open to be formed.It is a reality of positive photoresist layer in photoresist layer In example, the expose portion of photoresist layer is removed during developing process.The patterning of photoresist layer also includes such as each stage In each baking step other processing steps.For example, can be after photoetching exposure process and before developing process (PEB) technique is bakeed after implementing exposure.
In certain embodiments, imaging system 600 has the cone for measuring the light that projection optics 608 can be collected Size numerical aperture.In instances, numerical aperture is proportional to sin (θ), wherein, θ be projection optics 608 most It is big to collect half angle.
With reference to figure 6B example, imaging system is determined using the optical parametric (e.g., numerical aperture) of imaging system 600 600 point spread function (PSF) 620.PSF 620 describes response of the imaging system 600 to point source or punctiform object.Imaging The PSF of system 600 can by radiation source 602 wavelength and imaging system 600 optical parametric (e.g., numerical aperture) shadow Ring.In the example shown in fig. 6b, PSF 620 includes main lobe 622, and its width W3 is directly proportional to wavelength and and numerical value Aperture is inversely proportional.PSF 620 includes the secondary lobe 626 and 630 with positive amplitude and secondary lobe 624,628 and with negative amplitude 632.In certain embodiments, the absolute value of the peak amplitude of the secondary lobe away from main lobe 622 is less than the secondary lobe closer to main lobe 622 Peak amplitude absolute value.
Fig. 6 C also show PSF 620 amplitude, and it illustrates the master in the plane of delineation corresponding to Fig. 6 B PSF 620 Valve and secondary lobe.In Fig. 6 C example, PSF 620 main lobe and secondary lobe are represented by the concentric ring with center 634 and also claimed For PSF 620 ring.Ring 626 and 630 has positive amplitude, and also known as positive ring 626 and 630.Ring 624,628 and 632 has Negative amplitude, and also known as negative ring 624,628 and 632.Each ring has width.For example, ring 624 has and x1 and x2 The distance between equal width, ring 626 there is the width equal with the distance between x2 and x3, ring 628 has and x3 and x4 The distance between equal width, ring 630 has the width equal with the distance between x4 and x5, and ring 632 has and x5 Width equal the distance between x6.
With reference to figure 1A, Fig. 7 A, Fig. 7 B, Fig. 8 A, Fig. 8 B, Fig. 9 A, Fig. 9 B, Figure 10, Figure 11 and Figure 12, method 100 carry out to Frame 110, wherein, restoring area is determined based on the point spread function of imaging system.In Fig. 7 A, Fig. 7 B, Fig. 8 A, Fig. 8 B, Fig. 9 A In Fig. 9 B example, the punctual openings in transmission mask are used to show the restoring area point in the restoring area of each opening position How shape opening influences the aerial image intensity of the aerial image of the defects of the defects of mask region region punctual openings.For What is discussed is clear, and punctual openings have infinitesimal size, so that the amplitude distribution base of the aerial image of punctual openings This is identical with the point spread function of imaging system.
It should be noted that although transmission mask is used for those accompanying drawings as example, but it is not intended to limitation.In some implementations Example in, the point spread function of the pip in reflection mask with reference to described by figure 7A, Fig. 7 B, Fig. 8 A, Fig. 8 B, Fig. 9 A and Fig. 9 B Those point spread functions it is substantially similar.In addition, below with reference to Figure 10, Figure 11 and Figure 12 detailed description, in some implementations Example in, the master unit of the reparation for mask, aerial image be repair master unit (including original master unit, defect area and Restoring area) whole region combination contribution.In such an embodiment, come from by integrated (e.g., using convolution operation) The point spread function of the point in the whole area of the master unit of reparation is contributed to calculate the intensity of indivedual points in imaging plane.
With reference to figure 7A and Fig. 7 B example, mask 700 has defect area punctual openings 702.Defect area punctual openings In 702 the defects of being located at mask regions, and also known as defect area punctual openings 702.Amplitude distribution 620-1 shows imaging The defects of focal plane of system region punctual openings 702 aerial image amplitude distribution.Amplitude distribution 620-1 can be with Fig. 6 A point spread function 620 is substantially similar.As shown in amplitude distribution 620-1, at position 708, defect area point-like is opened Mouthfuls 702 aerial image (e.g., has and the sky of the punctual openings of phase shift not due to defect with substantially equal to zero phase Middle image identical phase) and with the occasion of amplitude A 1.
In certain embodiments, it is determined that the image intensity for needing to increase at position 708 (e.g., compensates the figure as caused by defect As loss of strength).In such an embodiment, punctual openings 704 are added to mask 700.Punctual openings 704 are located at repairing for mask In multiple region, and also known as restoring area punctual openings 704.Selection is between defect area punctual openings 702 and restoring area The distance between punctual openings 704 D1, so as to increase the image intensity at position 708 by restoring area punctual openings 704. Amplitude distribution 620-2 shows the amplitude point of the aerial image of the restoring area punctual openings 704 of the focal plane of imaging system Cloth, and can be substantially similar with Fig. 6 A point spread function 620.As shown in Figure 7 B, amplitude distribution 620-2 includes positive ring 622nd, 626 and 630, wherein, the amplitude of the aerial image of punctual openings 704 is just.Amplitude distribution 620-2 also includes negative ring 624th, 628 and 632, wherein, the amplitude of the aerial image of punctual openings 704 is negative.
In certain embodiments, in order to increase the image intensity at position 708, secondary lobe and main lobe based on point spread function Width carry out chosen distance D1 so that position 708 is located at one in amplitude distribution 620-2 positive ring 622,626 and 630 In individual.In special example, distance D1 is proportional to the distance D2 at the center 634 of position 708 to amplitude distribution 620-2, and And position 708 falls in amplitude distribution 620-2 positive ring 626.In the special example, the amplitude at position 708 is amplitude It is distributed the amplitude of the combination of 620-1 amplitude A 1 and amplitude distribution 620-2 amplitude A 2.Because both amplitude A 1 and A2 have Have on the occasion of so the absolute value of the amplitude of combination is more than the absolute value of amplitude A 1.So, restoring area punctual openings 704 are passed through Add the image intensity of position 708.
With reference to figure 8A and Fig. 8 B, in certain embodiments, it is determined that needing to reduce region punctual openings the defects of at position 708 The image intensity of 702 aerial image.In such embodiments, restoring area punctual openings 704 are added to mask 700, Wherein, select between the distance between defect area punctual openings 702 and restoring area punctual openings 704 D3, so as to reduce position Put the image intensity at 708.Amplitude distribution 620-3 shows the restoring area punctual openings 704 of the focal plane of imaging system Aerial image amplitude distribution, and can be substantially similar with Fig. 6 A point spread function 620.As shown in Figure 8 B, amplitude point Cloth 620-3 includes positive ring 622,626 and 630, wherein, the amplitude of the aerial image of restoring area punctual openings 704 is just.Width Degree distribution 620-3 also includes negative ring 624,628 and 632, wherein, the amplitude of the aerial image of restoring area punctual openings 704 It is negative.
In certain embodiments, in order to reduce the image intensity at position 708, secondary lobe and main lobe based on point spread function Width carry out chosen distance D1 so that position 708 is located at one in amplitude distribution 620-3 negative ring 624,628 and 632 In individual.In special example, distance D3 is proportional to the distance D4 at the center 634 of position 708 to amplitude distribution 620-3, and And position 708 falls in amplitude distribution 620-3 negative ring 624.In the special example, the amplitude at position 708 is amplitude It is distributed the amplitude of the combination of 620-1 amplitude A 1 and amplitude distribution 620-3 amplitude A 3.Because amplitude A 1 has on the occasion of and width Degree A3 has negative value, so the absolute value of the amplitude of combination is less than the absolute value of amplitude A 1.So, restoring area point-like is passed through Opening 704 reduces the image intensity of position 708.
With reference to figure 9A and Fig. 9 B, in certain embodiments, at position 708, the aerial shadow of defect area punctual openings 702 As have the phase of substantially equal with 180 degree (radiation e.g., from defect area punctual openings 702 due to defect and phase shift about 180 degree) and with negative value amplitude A 1.In such embodiments, in order to increase the image intensity at position 708, will repair Region punctual openings 704 are added to mask 700, wherein, select between defect area punctual openings 702 and restoring area point-like Be open the distance between 704 D5, so as to increase the image intensity at position 708.In certain embodiments, amplitude distribution 620-4 Show the amplitude distribution of the aerial image of the restoring area punctual openings 704 of the focal plane of imaging system, and can be with Fig. 6 A point spread function 620 is substantially similar.As shown in Figure 9 B, amplitude distribution 620-4 includes positive ring 622,626 and 630, its In, the amplitude of the aerial image of restoring area punctual openings 704 is just.Amplitude distribution 620-4 also include negative ring 624,628 with And 632, wherein, the amplitude of the aerial image of restoring area punctual openings 704 is negative.
In certain embodiments, in order to increase the image intensity at position 708, secondary lobe and main lobe based on point spread function Width carry out chosen distance D5 so that position 708 is located at one in amplitude distribution 620-4 negative ring 624,628 and 632 In individual.In special example, distance D5 is proportional to the distance D6 at the center 634 of position 708 to amplitude distribution 620-4, and And position 708 falls in amplitude distribution 620-4 negative ring 624.In the special example, the amplitude at position 708 is amplitude It is distributed the amplitude of the combination of 620-1 amplitude A 1 and amplitude distribution 620-4 amplitude A 4.Because both amplitude A 1 and A2 have There is negative value, so the absolute value of the amplitude of combination is more than the absolute value of amplitude A 1.So, restoring area punctual openings 704 are passed through Add the image intensity of position 708.
In certain embodiments, wherein, at position 708, the aerial shadow of region punctual openings 702 the defects of mask 700 As the phase with substantially equal to 180 degree and with the amplitude A 1 with negative value, restoring area punctual openings 704 are added To mask 700 to reduce the image intensity at position 708.In such embodiments, select between defect area punctual openings The distance between 702 and restoring area punctual openings 704, so that position 708 is located at the width of restoring area punctual openings 704 Spend in one in the positive ring 622,626,630 of distribution.In the special example, the amplitude at position 708 is amplitude distribution The amplitude of the combination of 620-1 amplitude A 1 and the positive amplitude of the aerial image of restoring area punctual openings 704.Because amplitude A 1 has There is negative value, so the absolute value of the amplitude of combination is less than the absolute value of amplitude A 1.So, restoring area punctual openings 704 are passed through Reduce the image intensity of position 708.
With reference to figure 10, Figure 11 and Figure 12 example, the reparation in mask is determined using the point spread function of imaging system Region.In certain embodiments, (by the AIMS for mask or it is used for by being related to aerial image or Resist images measurement The SEM (SEM) of wafer) and the feedback loop of mask reparation determine restoring area.In certain embodiments, Using each simulation model simulation can be used to determine the restoring area in mask.
With reference to figure 10, in certain embodiments, simulation model includes the compensation method based on pixel.In such embodiment In, mask is divided into multiple areas, and each area is referred to as mask pixels or pixel.Then the state of pixel is changed repeatedly The printing image and desired pattern match of (e.g., whether respective pixel is included in restoring area) until the simulation on wafer.
In various embodiments, mask repairing model based on mask repair tool determines the size of pixel.At some In example, Pixel Dimensions are equal to or more than the minimum remanufactured component size that mask repair tool can produce.In some embodiments In, Pixel Dimensions are related to the effect and efficiency of the simulation for determining restoring area.In some instances, if Pixel Dimensions Too small (being less than minimum remanufactured component size), then which is beyond that the ability of mask repair tool and when consuming more simulation Between, and optimize no any actual improvement for mask restoring area.On the other hand, coarse mask pixels perhaps can not Masking tools are made full use of, and because the substantially bad resolution ratio triggered by larger Pixel Dimensions is unable to close to excellent The mask restoring area of change.
In some instances, mask pixels have common Pixel Dimensions.Alternatively, as shown in Figure 10, implement at some In example, mask pixels are of different sizes to improve the effect of simulation and efficiency.In Figure 10 example, absorbed layer 220 wraps Include around the absorbed inside part 1002 of defect area 212 and absorb part 1004 around the outside of interior section 1002, its In, the pixel in absorbed inside part 1002 and outside absorption part 1004 is of different sizes and/or shape.In some realities Apply in example, absorbed inside part 1002 and outside absorption part can be determined based on defect area 212 and point spread function 620 1004 size and dimension.In some instances, each pixel 1006 in absorbed inside part 1002 has than outside Absorb the first small Pixel Dimensions of the second Pixel Dimensions of each pixel 1008 of part 1004.In special example, First Pixel Dimensions are about a quarter of the second Pixel Dimensions.In other words, if pixel closer to defect area 212 (e.g., In internally positioned absorption part 1002), then can be that and if pixel is farther with smaller Pixel Dimensions by pixel definition (e.g., absorbed from defect area 212 positioned at outside in part 1004), then can be with bigger pixel chi by pixel definition It is very little.This technique can be used for picture element matrix of the generation with various Pixel Dimensions, so that closer defect area 212 Absorbing part 1002 has than absorbing the finer pixel resolution in part 1004 further from defect area 212, and this is provided More efficiently design and the effective optimization of restoring area.
It should be noted that although in Figure 10 example, pixel has rectangular shape, it should be appreciated that, can be by pixel It is defined as variously-shaped including square, circular, oval, pentagon, hexagon and any other suitable shape.
In certain embodiments, simulation is implemented to determine restoring area.Simulation is iteratively repeated modification restoring area and (e.g., led to Cross by pixel added to restoring area or from restoring area remove pixel), perform simulation steps be to determine the region newly repaired No more preferable (e.g., for realizing more preferable wafer pattern and/or meeting aerial image intensity scope) and it is then based on simulation step The technique that rapid result further changes restoring area.Can using rule-based method and/or based on the method for model come Application simulation.For rule-based method, for example, by depending on defect area, master unit and/or optical parametric and into As the offset rule inventory of the point spread function of system, restoring area (e.g., position, size, shape) is set.For based on mould The method of type, using pattern transfering process pattern metastasis model (e.g., including the imaging model of imaging process and/or development work The Development Model of Electron Beam Resist of skill) simulate the image of the printing on wafer, and restoring area is determined so that the image of simulation meets Image intensity demand and/or matched with the desired wafer image of master unit.
With reference to figure 11 and Figure 12, in some instances, the side using rule-based method and based on model in simulations The combination (also referred to as mixed method) of method.The initial restoring area for simulation can be provided using rule-based method. Initial restoring area for simulation is generated by using offset rule, the number repeatedly for simulation can be reduced.Also It can use based on the method for model and realize the phase on wafer to change this initial restoring area to optimize restoring area The pattern of prestige.
With reference to the example of figure 11, the initial restoring area for simulation is determined using rule-based method.At some In example, there is provided the set of offset rule is with the phase and amplitude according to defect area 212, the aerial image of defect area 212 Distribution and as described by above with reference to Fig. 6 A, Fig. 6 B, Fig. 6 C, Fig. 7 A, Fig. 7 B, Fig. 8 A, Fig. 8 B, Fig. 9 A and Fig. 9 B into As the point spread function and its oscillation property of system determine the position of initial remanufactured component, size and dimension.For example, can be with base In above with reference to described by Fig. 7 A, Fig. 7 B, Fig. 8 A, Fig. 8 B, Fig. 9 A and Fig. 9 B between defect area punctual openings 702 and repair The distance between region punctual openings 704 (e.g., distance D1, D3 and D5) determine offset rule.In certain embodiments, such as Shown in Figure 11 example, the phase of the aerial image in focal plane of defect area 212 is about 180 degree.In such embodiments, base In determining the set of offset rule above with reference to the distance D5 described by Fig. 9 A and Fig. 9 B.For example, according to offset rule, it is determined that Restoring area in area 1102 and 1106 can be used for the image intensity for reducing the image of defect area 212, wherein, it is based on The width in the Huan626He areas 622 of point spread function 620 determines area 1102 and 1106.In another example according to offset rule, it is determined that Restoring area in area 1104 and 1108 can be used for the image intensity for increasing the image of defect area 212, wherein, it is based on The width of the ring 624 and 628 of point spread function 620 determines area 1104 and 1108.Figure 11 illustrates example in, in order to Increase the image density of the image of defect area 212, there is provided initial restoring area 1110A and 1112A and area in area 1104 Initial restoring area 1114A in 1108 is for simulation.
With reference to the example of figure 12, simulation changes initial restoring area so that it is determined that reparation area using based on the method for model Domain.In certain embodiments, according to the mould of the empirical model characterized by experienced semiconductor crystal wafer data and test pattern Intend result to apply the method based on model.In certain embodiments, the method based on model include have above with reference to Fig. 6 B, The imaging model of the point spread function of imaging system described by Fig. 6 C, Fig. 7 A, Fig. 7 B, Fig. 8 A, Fig. 8 B, Fig. 9 A and Fig. 9 B, And the phase and amplitude based on defect area is distributed to calculate the aerial image intensity of master unit and/or defect area.
In certain embodiments, the method based on model includes having is converted to the against corrosion of Resist patterns by image intensity The Development Model of Electron Beam Resist of oxidant layer.Resist layer can include such as top anti-reflective coating (TAR) film, bottom antireflective coat film (BARC) and resist film multilayer film.The film resist that conversion can be related to the information with the resist in response to light rings Answer function.The response of resist can be included for exposure intensity, time for exposure and the response for responding radius.Conversion can be related to Resist development function, reflect the influence of the final Resist patterns for developing process.In certain embodiments, can change The convolutional calculation of imaging model is with including the conversion from aerial image to Resist patterns, so that the image of imaging model is strong Degree function can represent the Resist patterns after exposed and developed technique.
With reference to the example of figure 12, it illustrated therein is and pass through after the method based on model is applied to initial restoring area Mould quasi-definite restoring area 1110B, 1112B and 1202.In the example shown, by the way that pixel 1204 is added into Figure 11's Initial restoring area 1110A and remove pixel 1206,1208,1210 and 1212 from the initial restoring area and repair area to be formed Domain 1110B.Restoring area 1112B is formed by removing pixel 1214,1216 and 1218.Initial restoring area 1114A is removed, And add restoring area 1202.
Although it should be noted that providing the instantiation of the phase and amplitude distribution of defect area, these are only real Example is not intended to limit.In various embodiments, the aerial image of defect area can have any phase distribution (e.g., to have Between 0 degree of phase between 180 degree or more than 180 degree or with for aerial image different piece out of phase) and Amplitude distribution, and the simulation above with reference to described by Figure 11 and Figure 12 can be used to confirm that restoring area, so that defect The image intensity in region meets the strength range of needs.In addition, the configuration of restoring area is only exemplary, it is no intended to is limited System.It should be appreciated by those skilled in the art can use other configurations, and restoring area can have variously-shaped, bag Include square, rectangle, circle, ellipse, pentagon, hexagon and any other suitable shape.
With reference to figure 1A and Figure 13, then method 100 is carried out to frame 112, wherein, based on restoring area 1110B, 1112B and 1202 and mask repair tool mask repairing model come determine mask repair profile.In certain embodiments, mask reparation Model includes the various parameters of mask repair tool, such as including for etching characteristic of different shapes (e.g., speed, selectivity) With reparation accuracy.In some instances, mask repairing model provide realize it is higher repair accuracy mask repair tool with For forming special shape, for example, circular and oval compared to rectangle.It is special according to those in such example Shape repair profile 1302,1304 and 1306 for restoring area 1110B, 1112B and 1202 mask so as to wrapping to change Include the fillet indicated by mask repairing model.In some instances, can be changed according to the change that profile is repaired for mask Restoring area 1110B, 1112B and 1202.In instances, pixel 1308 is repaiied added to restoring area 1112B with compensating mask The change of multiple profile 1302,1304 and 1306.
With reference to figure 1A and Figure 14, method 100 is carried out to frame 114, wherein, renovation technique is performed to restoring area.In Figure 14 Show to the mask 200 after restoring area 1110B, 1112B and 1302 execution renovation techniques, wherein, remove restoring area Absorbed layer 220 in 1110B, 1112B and 1202 to form remanufactured component 1402,1404 and 1406 respectively.Renovation technique can be with Including the focused ion beam etching performed by mask repair tool or focus on electron beam induced etching.Pass through remanufactured component 1402nd, 1404 and 1406 exposure coating 206.Remanufactured component 1402,1404 and 1406 provides the radiation of additional reflection to mend The loss of strength as caused by defect area 212 is repaid, and recovers the corresponding resist to be formed in target (e.g., wafer substrate) Pattern.
In some instances, if Resist patterns defect corresponding with defect area 212 is smaller and in specification (e.g., Resist patterns defect has the width less than about 3nm), then it is assumed that the defects of mask 200 has passed through restoring area It is repaired.In various embodiments, the size and dimension of remanufactured component is selected, so that being repaired the radiation of part reflection not More than the threshold exposure of the Other substrate materials for being arranged in target, and such remanufactured component is also known as Subresolution and repaiied Multiple part.
With reference to figure 15A, Figure 15 B, Figure 15 C, Figure 15 D, Figure 16 A, Figure 16 B, Figure 16 C, Figure 16 D, Figure 17 A, Figure 17 B, figure 17C, Figure 17 D, Figure 18 A, Figure 18 B, Figure 18 C and Figure 18 D, various types of masks can be repaired with application method 100.Figure 15A, Figure 15 B, Figure 15 C, Figure 15 D, Figure 16 A, Figure 16 B, Figure 16 C, Figure 16 D show the mask 1500 that application method 100 is repaired. Figure 17 A, Figure 17 B, Figure 17 C, Figure 17 D, Figure 18 A, Figure 18 B, Figure 18 C, Figure 18 D show that the phase shift that application method 100 is repaired is covered Mould 1700.
With reference now to Figure 15 A and Figure 15 B example, there is provided include the binary in the defects of part 222 region 1504 (binary) mask 1500.In some are embodiment, mask 1500 includes substrate 1502, and the substrate includes fused silica (SiO2), vitreous silica, calcirm-fluoride or other suitable materials.In certain embodiments, binary mask 1500 includes absorbed layer 1508, the absorbed layer can include the single or multiple lift of the material selected from the group being made up of following material：Chromium (Cr), oxidation Chromium (CrO), titanium nitride (TiN), tantalum nitride (TaN), tantalum (Ta), titanium (Ti), Solder for Al-Cu Joint Welding (Al-Cu), palladium, boron carbide tantalum (TaBN), aluminum oxide (AlO), molybdenum (Mo), one-level other suitable materials.The mask 1500 shown in Figure 15 A and Figure 15 B In specific embodiment, according to IC layout patterns absorbed layer 1508 with including part 222.Covered when incident radiation 1510 is incident upon When on mould 1500, the absorbed layer 1508 of patterning absorbs radiation, so as to form the radiation 1512 of patterning.Further, for The embodiment, it is found that mask 1500 has defect area 1504 (e.g., having projection), wherein, through the figure of defect area 1504 The radiation 1512 of case does not have desired phase and/or amplitude.
With reference to figure 15C and Figure 15 D example, the normalization of the aerial image in focal plane of defect area 1504 is respectively illustrated Amplitude and intensity distribution.In special example, the aerial image of defect area 1504 is with about 1.2 maximum normalization width Angle value 1520, about 90 degree of phase and about 1.44 maximum normalized intensity value 1524.
With reference to figure 16A, Figure 16 B, Figure 16 C and Figure 16 D, in certain embodiments, execution method 100 is to repair mask 1500.For example, at the frame 110 of method 100, the aerial shadow of point spread function and defect area 1504 based on imaging system The phase and amplitude of picture is distributed to determine restoring area.With reference to figure 16A, Figure 16 B, show to the execution method 100 of mask 1500 To repair the mask 1500 after defect area.The absorbed layer in region by removing remanufactured component 1602 is come in mask Remanufactured component 1602 is formed on 1500.Radiation 1604 through remanufactured component 1602 compensates the intensity as caused by defect area 1504 Loss.
With reference to figure 16C and Figure 16 D example, lacking after remanufactured component to be added to mask 1500 is respectively illustrated Fall into the normalization amplitude and intensity distribution of the aerial image in focal plane in region 1504.In special example, defect area 1504 Aerial image (added about from maximum normalization range value 1520 with about 1.4 maximum normalization range value 1620 17%) the maximum normalized intensity value 1624 (adding about 36% from maximum normalized intensity value 1524) with about 2.
With reference now to Figure 17 A and Figure 17 B example, there is provided the optional phase including the defects of part 222 region 1708 Move mask 1700.In such example, part 222 corresponds to phase shifting region, and also known as phase shifting region 222.At some It is in embodiment, mask 1700 includes substrate 1702, and the substrate includes fused silica (SiO2), vitreous silica, calcirm-fluoride or its His suitable material.Substrate 1702 includes phase shifting region 222 and non-phase-shifted region 1706.Through the radiation of phase shifting region 222 1714 compared to the phase shift of the radiation 1716 about 180 degree through non-phase-shifted region 1706.Circuit block can be utilized through adjacent region The radiation of the anti-phase 180 degree in domain (e.g., radiates 1714 and 1716) formed on wafer.Further, for the embodiment, find Mask 1700 has positioned at the defects of phase shifting region 222 region 1708 (e.g., having depression), through defect area 1708 Radiation 1714 does not have desired phase.
With reference to figure 17C and Figure 17 D example, the normalization of the aerial image in focal plane of defect area 1708 is respectively illustrated Amplitude and intensity distribution.In special example, the aerial image of defect area 1708 is with about 1.2 maximum normalization width Angle value 1720, about 45 degree of phase and about 1.44 maximum normalized intensity value 1724.
With reference to figure 18A, Figure 18 B, Figure 18 C and Figure 18 D, in certain embodiments, execution method 100 is to repair mask 1700.For example, at the frame 110 of method 100, the aerial shadow of point spread function and defect area 1708 based on imaging system The phase and amplitude of picture is distributed to determine restoring area.In wherein mask 1700 is the embodiment of phase shifting mask, in frame 110 Place, also determine (simulation e.g., carried out by using phase shifting mask model) and different remanufactured components corresponding to different restoring areas Can have different thickness so that through these remanufactured components radiation can have different phase (e.g., it is anti-phase about 180 degree).With reference to figure 18A, Figure 18 B, Figure 18 C and Figure 18 D, after showing execution method 100 to repair defect area 1708 Mask 1700.Remanufactured component 1802 and 1804 is formed on mask 1700 by removing the absorbed layer 1710 in restoring area. In addition, remanufactured component 1802 has the thickness different from the thickness of remanufactured component 1804, so that passing through remanufactured component 1802 The about anti-phase 180 degree of radiation with remanufactured component 1804.In instances, through remanufactured component 1804 radiation have with through non-phase Move the radiation identical phase in region 1706.
With reference to figure 18C and Figure 18 D example, lacking after remanufactured component to be added to mask 1700 is respectively illustrated Fall into the normalization amplitude and intensity distribution of the aerial image in focal plane in region 1708.In special example, defect area 1708 Aerial image (added about from maximum normalization range value 1720 with about 1.9 maximum normalization range value 1820 58%) the maximum normalized intensity value 1824 (adding about 192% from maximum normalized intensity value 1724) with about 3.6.
The embodiment provides the advantage better than prior art, but it is to be understood that different embodiments can be with Different advantages is provided, not every advantage must all be discussed herein, and be all realities without specific advantage Apply what example was required for.One advantage of some embodiments is, can pass through the shape in the non-defective region around defect area Lost into remanufactured component with compensating the image intensity caused by defect to repair the defects of mask.In addition, by using imaging The oscillation picture of the point spread function of system, restoring area can be determined efficiently and actually using simulation.In addition, By the way that in simulations using the combination of rule-based method and the method based on model, the restoring area of optimization can be being confirmed Reduce the number repeatedly of simulation while for realizing the desired pattern in target.
Therefore, one embodiment of the present of invention is related to mask restorative procedure.Check mask with lacking the defects of location mask Fall into region.Obtain the phase distribution of the aerial image of defect area.Determine the point spread function of imaging system.Based on defect area Aerial image phase distribution and point spread function confirm one or more restoring areas of mask.One to mask or Multiple restoring areas perform renovation technique to form one or more remanufactured components.
Another embodiment of the present invention is related to the method for far ultraviolet (EUV) mask including receiving patterning.Patterning EUV mask includes the absorption region with absorbing material, defines the reflector space and defect of master unit.It is determined that caused by defect Intrusion reflector space the defects of region.Obtain the phase distribution of the image of defect area.The point spread function of imaging system is provided Number.Restoring area in absorption region is determined according to the phase distribution of point spread function and the image of defect area.Using covering Mould fix tool removes the absorbing material of restoring area to form remanufactured component.
Another embodiment of the present invention is related to including receiving the mask with printing unit and defect.Mask is checked to position The defects of defect region.Determine the point spread function of imaging system.Mask is confirmed based on point spread function and defect area Restoring area.Renovation technique is performed to form remanufactured component to the restoring area of mask using mask repair tool.Mask is sudden and violent The radiation being exposed in imaging system to produce the first radiation from printing unit and produces the second radiation from remanufactured component.First spoke Penetrate the photoresist radiated with second for giving away one's position.
According to one embodiment of present invention, wherein, confirm that one or more of restoring areas include：Based on the point The oscillation picture of spread function confirms one or more of restoring areas.
According to one embodiment of present invention, wherein, described one is confirmed based on the oscillation picture of the point spread function Individual or multiple restoring areas include：Determined based on the main lobe of the point spread function around the firstth area of the defect area Domain；First secondary lobe of the neighbouring main lobe based on the point spread function determines the secondth area around the first area Domain；And the second secondary lobe of neighbouring first secondary lobe based on the point spread function determines around the second area 3rd region；Wherein, each restoring area is all located at the one of the first area, the second area and the 3rd region In individual.
According to one embodiment of present invention, wherein, the aerial image of the defect area has the phase equal to 180 degree Position, and wherein, the first restoring area is located in the second area.
According to one embodiment of present invention, wherein, described one is confirmed based on the oscillation picture of the point spread function Individual or multiple restoring areas include：3rd secondary lobe of neighbouring second secondary lobe based on the point spread function determines to surround 4th region in the 3rd region；And wherein, the second restoring area is located in the 4th region.
According to one embodiment of present invention, wherein, the aerial image of the defect area has null phase, with And wherein, one or more of restoring areas be located at the first area and the 3rd region it is at least one in.
According to one embodiment of present invention, wherein, confirm that one or more of restoring areas include：Using for inciting somebody to action Part defined in the mask be transferred to the pattern metastasis model of the pattern transfering process of wafer change it is one or Multiple restoring areas.
According to one embodiment of present invention, wherein, confirm that one or more of restoring areas include：Use multiple pictures Usually represent the mask；And one or more of restoring areas are defined using one or more pixels.
According to one embodiment of present invention, wherein, represent that the mask includes using the multiple pixel：Using multiple First pixel represent the mask around the first area of the defect area, wherein, each first pixel is with the One size；And the second area around the first area of the mask is represented using multiple second pixels, wherein, it is each Individual second pixel all has second size bigger than the first size.
According to one embodiment of present invention, wherein, the extreme ultraviolet mask of the patterning includes：Low thermal expansion material (LTEM) substrate；Reflecting multilayer above the low thermal expansion material substrate；Buffering above the reflecting multilayer Layer；And to form the absorbed layer of the patterning of the absorption region above the cushion, wherein, the patterning Opening in absorbed layer exposes the cushion to form the reflector space.
According to one embodiment of present invention, wherein, obtaining the phase distribution of the image of the defect area includes：Generation The surface profile of the defect area；The film sedimentation model of reflecting multilayer and cushion for the mask is provided；Using institute Film sedimentation model is stated, the deformation data of the reflecting multilayer and the cushion is determined based on the surface profile；And make The phase distribution of the image of the defect area is generated with the deformation data.
According to one embodiment of present invention, wherein, obtaining the phase distribution of the image of the defect area includes：Institute The first intensity distribution of the first aerial image that the defect area is obtained at first plane of delineation of imaging system is stated, wherein, Described first image plane is located at the opening position of the first distance apart from the focal plane of the imaging system；In the imaging system Second plane of delineation at obtain the defect area the second aerial image the second intensity distribution, wherein, second figure Image plane is located at the opening position of the second distance apart from the focal plane of the imaging system；And use first intensity distribution The image of the defect area is rebuild with second intensity distribution and first distance and the second distance Phase distribution.
According to one embodiment of present invention, wherein, first intensity distribution and the second intensity distribution bag are obtained Include：First intensity distribution and the last the second are obtained using the actinicity checking tool configured according to the imaging system Degree distribution.
According to one embodiment of present invention, method also includes：Mask repairing model based on the mask repair tool To adjust the profile of the restoring area.
According to one embodiment of present invention, method also includes：It is determined that the phase distribution of the image of the defect area Before, a part for the absorption region in the defect area is removed.
According to one embodiment of present invention, wherein, the first intensity of first radiation is more than the described second radiation Second intensity, and wherein, the second intensity of second radiation is less than the threshold exposure of the photoresist of the target.
According to one embodiment of present invention, wherein, determined based on the oscillation picture of the point spread function described in repair Multiple the distance between region and the defect.
According to one embodiment of present invention, wherein, the mask is phase shifting mask.
The part of some embodiments discussed above so that those skilled in the art may be better understood the present invention's Each embodiment.It should be appreciated by those skilled in the art that easily it can design or change using based on the present invention Others processing and structure introduce embodiment identical purpose and/or realize same advantage for reaching with of the invention.This Art personnel it should also be appreciated that these equivalent structures without departing from the spirit and scope of the present invention, and without departing substantially from In the case of the spirit and scope of the present invention, a variety of changes can be carried out, replaces and changes.
1. a kind of method for repairing mask, methods described include：
The defects of checking the defects of mask is to position mask region；
The phase distribution of the aerial image of the defect area is obtained in imaging systems；
Determine the point spread function of the imaging system；
The phase distribution of aerial image based on the defect area and the point spread function confirm the one of the mask Or multiple restoring areas；And
Renovation technique is performed to form one or more remanufactured components to one or more restoring areas of the mask.
CN201710358246.XA 2016-06-06 2017-05-19 method for repairing mask CN107463065A (en)
US62/346,273 2016-06-06
US15/254,607 2016-09-01
CN107463065A true CN107463065A (en) 2017-12-12
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2019-12-24 WD01 Invention patent application deemed withdrawn after publication
Application publication date: 20171212