KR102256578B1 - Apparatus and method for ptychography imaging - Google Patents

Abstract

Disclosed is an apparatus and method for tyographic imaging of an object. A typographic imaging method, comprising: obtaining a plurality of diffraction patterns by irradiating an inspection light source (probe) on the subject; Calculating phases for the plurality of diffraction patterns; Inputting the calculated phase information as initial phase information for typographic repetitive imaging; Performing typographic repetitive imaging; And acquiring information on one or more of the test object and the test light source that are finally updated as a result of the repeated typography imaging.

Description

Typographic imaging apparatus and method TECHNICAL FIELD

The present invention relates to a typography imaging apparatus and method, and relates to a typographic imaging apparatus and method for reconstructing a surface image of an object by using a phase guide.

Typography technology is an algorithm used in transmission-type optical systems using wavelengths in the x-ray range, and typography algorithms for reflection-type optical systems are being studied. Existing typography algorithms include ptychographic iterative engine (PIE), extended PIE (Epie), and position correcting PIE (pcPIE) derived therefrom. In the prior art, phase information, which is initial input information, is input as a random value, and the original phase information is restored using the diffracted light intensity constraint and the overlapped region constraint. In the case of the derived ePIE and pcPIE, an additional calculation process is included to solve the occurrence of an error in phase reconstruction due to an error in a constraint condition.

In the conventional typography technology, the initial input phase value is randomly set and the square root value of the diffracted light intensity is continuously substituted during the calculation process in order to restore phase information that plays an important role in determining the quality and convergence speed of the final reconstructed image. The relative position information between the constraint condition and the diffraction pattern is used as the constraint condition.

In this case, it is necessary to minimize the error of the constraint condition in order to restore the phase information to approximate the true value. However, this is not practically possible, and an error occurs in the finally restored phase value due to an error occurring in the error of the constraint condition, resulting in a decrease in accuracy. In addition, there is a problem that the number of operations for restoring the phase value increases.

In other words, when initial phase information is randomly input in typographic imaging as in the prior art, there is no reproducibility of the restored phase value due to an error in a constraint condition, or a phase restoration is not performed due to a stagnation phenomenon. Problems arise.

An object of the present invention for solving the above problems is to provide a typographic imaging method for an object to be inspected.

Another object of the present invention for solving the above problems is to provide an apparatus using a typographic imaging method.

Another object of the present invention for solving the above problems is to provide a method for inspecting a subject.

A typographic imaging method for an object according to an embodiment of the present invention for achieving the above object includes: obtaining a plurality of diffraction patterns by irradiating an inspection light source (probe) on the object; Calculating phases for the plurality of diffraction patterns; Inputting the calculated phase information as initial phase information for typographic repetitive imaging; Performing typographic repetitive imaging; And acquiring information on one or more of the test object and the test light source that are finally updated as a result of the repeated typography imaging.

The phases for the plurality of diffraction patterns may be calculated using single-shot coherence diffraction imaging (CDI).

The single-shot CDI may be performed using an error reduction algorithm (ERA) or a hybrid input-output (HIO) algorithm.

The step of performing the typographic repetitive imaging may include applying constraints on the intensity of diffracted light and the overlapped region information.

The phases of the plurality of diffraction patterns have a characteristic in which the phase of the object and the phase of the inspection light source are convolved.

The calculated phases of the plurality of diffraction patterns may be input as initial phase information of the subject among the initial phase information.

The typographic imaging method may further include reconstructing a surface image of the test subject using information on the last updated subject.

A typographic imaging apparatus according to an embodiment of the present invention for achieving the other object may include at least one processor and a memory for storing at least one instruction executed through the processor, and the at least one instruction The instructions for causing the processor to obtain a plurality of diffraction patterns by irradiating an inspection light source with respect to an object to be inspected; Instructions to calculate phases for the plurality of diffraction patterns; A command for inputting the calculated phase information as initial phase information for typographic repetitive imaging; Instructions to perform typographic repetitive imaging; And a command for obtaining information on at least one of the test object and the test light source that are finally updated as a result of the typographic repetitive imaging.

The phases for the plurality of diffraction patterns may be calculated using single-shot coherence diffraction imaging (CDI), and the single-shot CDI is an Error Reduction Algorithm (ERA) or Hybrid Input-Output; HIO) algorithm.

The command for performing the typographic repetitive imaging may include a command for applying a constraint on the intensity of the diffracted light and the overlapped area information.

In addition, the at least one command may further include a command to reconstruct a surface image of the test subject using information on the last updated subject.

The phases of the plurality of diffraction patterns have a characteristic in which the phase of the object and the phase of the inspection light source are convolved.

The calculated phases of the plurality of diffraction patterns may be input as initial phase information of the subject among the initial phase information.

The last updated information on the subject may be used to inspect a mask or a mask to which a pellicle is attached.

A test object inspection method according to an embodiment of the present invention for achieving the above another object includes: obtaining a plurality of diffraction patterns by irradiating an inspection light source (probe) on the test object; Calculating phases for the plurality of diffraction patterns; Inputting the calculated phase information as initial phase information for typographic repetitive imaging; Performing typographic repetitive imaging; And reconstructing a surface image of the subject by using the result of the repeated typography imaging.

Here, the subject may be a mask for an extreme ultraviolet exposure process or a mask to which a pellicle is combined.

According to the embodiments of the present invention as described above, by improving the accuracy of phase information that is important during typography imaging, it is possible to improve the quality and convergence speed of the final image in the measurement and inspection of the mask pattern for the extreme ultraviolet exposure process. .

Therefore, it is possible to improve the productivity and resolution in the mask inspection for the extreme ultraviolet exposure process.

1 is a conceptual diagram illustrating an example of a typical typographic imaging.
2 shows an example of a conventional method of tyographic imaging.
3 is a flowchart of a tyography imaging method using a phase guide according to an embodiment of the present invention.
4 is a conceptual diagram of acquiring initial phase information and performing typographic imaging using HIO operation according to an embodiment of the present invention.
5 is a block diagram of a typographic imaging apparatus according to an embodiment of the present invention.

In the present invention, various modifications may be made and various embodiments may be provided, and specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention. In describing each drawing, similar reference numerals have been used for similar elements.

Terms such as first, second, A, and B may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. The term “and/or” includes a combination of a plurality of related described items or any of a plurality of related described items.

When a component is referred to as being "connected" or "connected" to another component, it is understood that it may be directly connected or connected to the other component, but other components may exist in the middle. It should be. On the other hand, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that there is no other component in the middle.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof does not preclude in advance.

Unless otherwise defined, all terms used herein including technical or scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in the present application. Does not.

The present invention relates to a typography algorithm technology for acquiring a single image by connecting multiple diffraction patterns acquired so that an overlapping area occurs, and more particularly, to improve the accuracy of phase information, which is important during typographic imaging. It is an algorithm including a phase guide operation to improve the quality and convergence speed of the final image.

More specifically, the present invention relates to an algorithm for calculating a phase value calculated in a typographic imaging process more accurately and at a high speed. The initial input phase value is not random, but by inputting the phase information calculated first through the single shot CDI technique in each diffraction pattern, it is possible to reduce the accurate phase information and calculation speed compared to the prior art.

At this time, since inspection and measurement techniques using different wavelengths cannot correctly evaluate the characteristics of the mask for the extreme ultraviolet exposure process, an observation technique using the EUV wavelength is required. However, manufacturing a lens for image formation at X-ray and EUV (extreme ultraviolet) wavelengths is difficult due to short wavelengths, and sophisticated optical system control is required to secure a resolution of several tens of nm. There is a difficulty in controlling the physical error that occurs in this process. The present invention relates to an observation technique that solves a problem arising from an error in an imaging optical system, minimizes damage to a biological sample, and correctly analyzes the characteristics of a subject.

The information to be finally acquired in typographic imaging is the surface image and phase information of the subject. To this end, Fourier and inverse Fourier calculations are performed based on diffracted light information and constraint conditions. In this case, it is the accuracy of the constraint that determines the quality and convergence speed of the final image. When an error occurs in the constraint condition, a particularly large error in the reconstructed phase value occurs.

The characteristic of this technology is to restore the true value close to the real value through iterative operation, and the constraint condition is the parameter that has the greatest influence on the restoration of the approximate value close to the true value in the inverse problem operation.

In the present invention, as described above, an additional operation for a phase-guide is introduced in order to solve the problem that an error occurs in phase restoration due to an error in a constraint condition.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram illustrating an example of a typical typographic imaging.

The algorithm showing the concept in FIG. 1 may be a ptychographic iterative engine (PIE).

Typography is a method of measuring diffraction data from a scanning transmission electron microscope (STEM) at each probe position serving as a light source, and converting a 4D data set as a result of the measurement to derive a phase. The advantage of typography is that only diffraction data is used, there is no limitation on the specimen, and a relatively wide range of views can be obtained. The disadvantages are that the data collection time is very long, there is a problem of drift and contamination of the sample, and the probe has to be moved very precisely.

PIE (ptychographic iterative engine) is a proposed technique to overcome these shortcomings and combines the strengths of typography and iterative techniques. Referring to FIG. 1, in the method, a sample does not move, and an indident radiation source or an aperture positioned after the sample moves to obtain several diffraction patterns.

This method avoids the alignment problem and can obtain a higher resolution image because no lens is required. Such a typography algorithm is a technology that can be used to image surface defects and pattern loss of pellicles and masks for the extreme ultraviolet ray exposure process over a large area, and is suitable for the mask inspection technology of extreme ultraviolet ray exposure technology that is expected to be applied in the mass production process. Can be applied. As the mask inspection technology for the extreme ultraviolet exposure process has not been established, research and development of various types of inspection technologies are in progress.

Typographic imaging is an inverse problem operation that collects a light source diffracted from an object and calculates an original image from it inversely. This technology is a category of Coherent Diffraction Imaging (CDI) that restores the original phase and image by setting various constraints on the diffraction pattern in which the phase information is lost.

In such general typographic imaging, in order to restore lost phase information, phase information in a random form is input as an initial value, and the phase of an object is searched through iterative operations of Fourier and inverse Fourier transforms. In this process, the square root value of the diffraction light intensity is continuously substituted during the calculation process, and the actual phase value can be calculated by inserting a constraint condition specifying the overlapped region information between the diffraction patterns.

2 shows an example of a conventional method of tyographic imaging.

Referring to FIG. 2, in conventional typographic imaging, first, diffraction pattern data is obtained through a diffraction light collection process for imaging an object (S21). Each diffraction pattern data consists of a convolutional relationship between an object and a probe.

At this time, since information on the subject and the inspection light source is unknown, a random value is provided as initial input information, and a typographic imaging operation is started using the random initial value. In this case, the arbitrary initial value may include an arbitrary amplitude and a random phase 11 for the object, and an arbitrary amplitude and an arbitrary phase 12 for the probe.

In order to reconstruct the phase information lost in the process of collecting the diffracted light and reconstruct the surface image of the subject, a typographic imaging operation is performed a plurality of times, for example, X times (S220). In this process, constraints on the diffracted light intensity and overlapping area information are applied.

When the X times typographic imaging operation is completed, the finally updated object and the last updated probe are obtained (S231, S232). That is, the amplitude and phase information of the object and the inspection light source are updated. At this time, since a random value was used as the initial object and initial probe values, if an error in the constraint condition occurs, an error occurs in the amplitude and phase information of the finally updated object and the inspection light source. This is because it is a technology that has the characteristic of performing this inverse problem operation, and the errors of the given conditions and constraints in the inverse problem operation act as errors in the final result.

In addition, the error of the constraint condition during the operation process degrades the accuracy of the operation in which the algorithm restores an approximate value close to the true value. This is highly correlated with the constraint condition of continuously substituting the square root value of the diffracted light intensity, and the phase information is restored while inputting the intensity constraint condition during the calculation process. If an error occurs in the constraint condition, a result value with a large error is derived. It is done.

In the present invention, to solve this problem, an initial phase information value is inputted as a value approximating a true value rather than a random value.

3 is a flowchart of a tyography imaging method using a phase guide according to an embodiment of the present invention.

In the present invention, inspection is performed using an inspection light source having a wavelength of 13.5 nm, which is the same as the wavelength used in extreme ultraviolet exposure, and in the prior art, a phase guide is used to solve the deterioration of the quality of the final observed image due to an error in the constraint condition. ) Operation is introduced.

Referring to FIG. 3 in more detail, first, diffraction pattern data is obtained through a diffraction light collection process for imaging an object (S310). Each diffraction pattern data consists of a convolutional relationship between an object and a probe.

Thereafter, a phase is primarily calculated using a single-shot CDI for each of the N pieces of diffracted light data in which the overlapping region exists (S320). In this case, the single-shot CDI may be an error reduction algorithm (ERA) or a hybrid input-output (HIO) algorithm. Here, the phase information calculated primarily can be relatively accurately restored compared to the prior art even if an error exists in the constraint condition.

Phase information, which is primarily calculated using the single-shot CDI, is input as initial information for typographic imaging (S330). In this case, the initial information may be phase information of the subject, that is, the object.

Thereafter, the typographic imaging operation is repeatedly performed a plurality of times (S340). In this process, constraints on the diffracted light intensity and overlapping area information are applied.

When the X times typographic imaging operation is completed, the finally updated object and the last updated probe are obtained (S351 and S352). That is, amplitude and phase information of the test object and the test light source are updated. In this case, since the phase information calculated primarily is used as the initial phase information of the object, even if an error exists in the constraint condition, the phase information can be relatively accurately restored compared to the prior art.

That is, unlike the prior art, the imaging method according to the present invention illustrated in FIG. 3 further includes a process of calculating initial phase information for a phase guide before performing typographic imaging using N diffraction patterns. For initial phase information calculation, a single shot CDI technology such as ERA or HIO can be used, and the phase information obtained through it has the following characteristics.

In the case of single-shot CDI, since there is no process of deconvolving and updating the test object and the test light source, the acquired phase information has a characteristic in which the phase information of the test subject and the test light source is convolved. However, since the phase information is greatly influenced by the subject due to the nature of the system, the calculated phase information is input as the initial phase information of the subject, so that even in the error of the constraint condition, stagnation or update in the direction of increasing the error during the calculation process is performed. It can act as a blocking phase guide.

Meanwhile, the subject can be inspected using the imaging method according to the present invention. In this case, the subject may be a mask for an extreme ultraviolet exposure process or a mask to which a pellicle is combined.

Accordingly, another aspect of the present invention may be related to a test subject inspection method, wherein the test subject inspection method includes: obtaining a plurality of diffraction patterns by irradiating an inspection light source (probe) on the test subject; Calculating phases for the plurality of diffraction patterns; Inputting the calculated phase information as initial phase information for typographic repetitive imaging; Performing typographic repetitive imaging; And reconstructing a surface image of the subject by using the result of the repeated typography imaging.

4 is a conceptual diagram of acquiring initial phase information and performing typographic imaging using HIO operation according to an embodiment of the present invention.

As described above, the present invention enables more accurate final phase information restoration by inputting the phase information that was primarily calculated through a single-shot CDI such as HIO or ERA as the initial value of the typography and calculating the second order through the typography. do.

In the embodiment of FIG. 4, initial phase information is obtained using HIO operation, but in other embodiments, initial phase information may be obtained using ERA or other single shot CDI.

Meanwhile, initial information in general typographic imaging may be expressed by an object function expressed by Equation 1 below and a probe function expressed by Equation 2 below.

That is, the initial information used for general typography operations is a complex value, and it is common that a random value is inputted. However, the imaging method proposed in the present invention does not set the phase of the initial O(r) value as a random value, but is primarily calculated through the HIO algorithm and then inputs the corresponding value as the initial value, enabling accurate and fast calculation. do.

HIO is an algorithm that calculates the original image with one diffraction pattern (system measurement value), and the diffraction pattern consists of a convolutional relationship between a probe and an object. At this time, since the detector for detecting the diffraction pattern has a rectangular detection area, the diffraction pattern is also collected in a rectangular area (for example, 512 pixels x 512 pixels). However, since the actual inspection light source has a circular shape, information on areas other than the circular shape is unnecessary information for calculating an image. Therefore, an approximate area of the inspection light source is designated, and this can be expressed as an r value.

The value derived from the HIO operation result can be expressed by Equation 3 below as _{g c+1 (r).}

In Equation 3, β is a number that determines how much the value in the probe area is reflected in the calculation of the value outside the area, and is the most important value in the entire calculation, and has a value between 0 and 1. Further, r is an inspection light source area, that is, an area in which it is determined that an actual light source is incident.

g _c+1 (r) means the value that has been calculated c+1 times for the entire area, _g'c (r) is the value calculated c times in the initially designated probe area, [g _c (r ) -βg _'c (r)] shows the results when the region outside the probe operation time c + 1. Other than the initially designated probe area, a weight is given to a value calculated in the probe area and expressed as a difference value from the previous calculation result.

_{Since g c+1} (r) expressed in Equation 3 is also formed in the form of (amplitude) * (phase), only the phase can be separated from the result and input as initial information of the typographic imaging operation. .

Finally, what is to be restored through typography is the amplitude and phase values of the object function. The diffraction pattern, which is the seed information of the imaging operation, consists of a convolutional relationship between the inspection light source and the inspection object. Accordingly, the inspection light source and the object to be inspected can be obtained by deconvolution of the diffraction pattern image.

In the deconvolution process, the diffraction pattern (reciprocal space) is inverse Fourier transform to obtain a real space image, and an update function is applied thereto to update the inspection light source and the subject information. As it is repeated, the accuracy of the reconstructed image is improved.

In summary, the imaging method proposed in the present invention is a method for improving the error of the inevitable constraint condition by software, and includes a preprocessing operation for inputting an initial phase value that has an important influence on the resolution and convergence speed of the reconstructed image. do. In this way, by incorporating the phase guide technology, it is possible to reduce a phase error that may occur randomly during phase restoration and alleviate a stagnation phenomenon.

Accordingly, the present invention is a technology that can become the core of improving the performance of a mask inspection technology in an extreme ultraviolet ray exposure process. More specifically, the algorithm according to the present invention can be used as a mask pattern measurement and inspection technology for an extreme ultraviolet light exposure process to be used in a semiconductor manufacturing process of a 1x nm node or less.

5 is a block diagram of a typographic imaging apparatus according to an embodiment of the present invention.

A typographic imaging apparatus according to an embodiment of the present invention includes at least one processor 510, a memory 520 for storing at least one command executed through the processor, and a transceiver 530 for performing communication. Can include.

The typographic imaging device 500 may further include an input interface device 540, an output interface device 550, and a storage device 560. Each of the components included in the typographic imaging apparatus 500 may be connected by a bus 570 to communicate with each other.

The typographic imaging apparatus 500 may also include a detector for collecting the diffraction pattern or may interwork with such a detector through the transmission/reception device 530.

The processor 510 may execute a program command stored in at least one of the memory 520 and the storage device 560. The processor 510 may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor in which methods according to embodiments of the present invention are performed. Each of the memory 520 and the storage device 560 may be configured with at least one of a volatile storage medium and a nonvolatile storage medium. For example, the memory 520 may be composed of at least one of a read-only memory (ROM) and a random access memory (RAM).

Here, the at least one instruction may include: an instruction for causing the processor to obtain a plurality of diffraction patterns by irradiating an inspection probe on an object; Instructions to calculate phases for the plurality of diffraction patterns; A command for inputting the calculated phase information as initial phase information for typographic repetitive imaging; Instructions to perform typographic repetitive imaging; And a command for obtaining information on at least one of the test object and the test light source that are finally updated as a result of the typographic repetitive imaging.

The phases for the plurality of diffraction patterns may be calculated using single-shot coherence diffraction imaging (CDI), and the single-shot CDI is an Error Reduction Algorithm (ERA) or Hybrid Input-Output; HIO) algorithm.

The command for performing the typographic repetitive imaging may include a command for applying a constraint on the intensity of the diffracted light and the overlapped area information.

In addition, the at least one command may further include a command to reconstruct a surface image of the test subject using information on the last updated subject.

The phases of the plurality of diffraction patterns have a characteristic in which the phase of the object and the phase of the inspection light source are convolved.

The calculated phases of the plurality of diffraction patterns may be input as initial phase information of the subject among the initial phase information.

The last updated information on the subject may be used to inspect a mask for an extreme ultraviolet exposure process or a mask to which a pellicle is combined.

Typographic imaging is a type of coherent diffraction imaging in which a light source diffracted from an object is collected and the surface image of the object is reconstructed by repeating Fourier and inverse Fourier operations therefrom. With the development of life science, medical, and semiconductor fields, observation technology for securing a resolution of several tens of nm is required in various industrial fields. Accordingly, the necessity of observation technology using very short wavelengths such as electron beam, X-ray, EUV (Extreme Ultraviolet), etc. has emerged. In particular, in the field of bio-imaging, observation technology without loss of biological samples is required. Accordingly, there is a need for an imaging technology for observing a sample by irradiating X-ray and EUV wavelengths in femtosecond units, and the present invention is related to this.

The invention also relates to EUV mask metrology and inspection techniques. In the case of a mask used in an extreme ultraviolet light exposure process (Extreme Ultraviolet Lithography, EUVL), it is manufactured to have a reflective structure due to the characteristic that EUV wavelengths are easily absorbed by all materials.

The operation of the method according to the embodiment of the present invention can be implemented as a computer-readable program or code on a computer-readable recording medium. The computer-readable recording medium includes all types of recording devices that store data that can be read by a computer system. In addition, a computer-readable recording medium may be distributed over a network-connected computer system to store and execute computer-readable programs or codes in a distributed manner.

Further, the computer-readable recording medium may include a hardware device specially configured to store and execute program commands, such as ROM, RAM, and flash memory. The program instructions may include not only machine language codes such as those produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like.

While some aspects of the invention have been described in the context of an apparatus, it may also represent a description according to a corresponding method, where a block or apparatus corresponds to a method step or characteristic of a method step. Similarly, aspects described in the context of a method can also be represented by a corresponding block or item or a feature of a corresponding device. Some or all of the method steps may be performed by (or using) a hardware device such as, for example, a microprocessor, a programmable computer or electronic circuit. In some embodiments, one or more of the most important method steps may be performed by such an apparatus.

In embodiments, a programmable logic device (eg, a field programmable gate array) may be used to perform some or all of the functionality of the methods described herein. In embodiments, the field programmable gate array may work with a microprocessor to perform one of the methods described herein. In general, the methods are preferably performed by some hardware device.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art will be able to variously modify and change the present invention within the scope not departing from the spirit and scope of the present invention described in the following claims. You will understand that you can.

Claims (19)

As a typographic imaging method for an object,
Obtaining a plurality of diffraction patterns by irradiating the test object with an inspection probe;
Calculating phases for the plurality of diffraction patterns;
Inputting the calculated phase information as initial phase information for typographic repetitive imaging;
Performing typographic repetitive imaging; And
Including the step of acquiring information on at least one of the test object and the inspection light source finally updated as a result of the repeated typography imaging,
The phase for the plurality of diffraction patterns is,
Typographic imaging method having a characteristic in which the phase of the test object and the phase of the inspection light source are convolved. The method according to claim 1,
The phase for the plurality of diffraction patterns is,
Typographic imaging method, calculated using single shot coherence diffraction imaging (CDI). The method according to claim 2,
The single shot coherence diffraction imaging (CDI),
A typographic imaging method performed using an Error Reduction Algorithm (ERA) or Hybrid Input-Output (HIO) algorithm. The method according to claim 1,
The step of performing the typography repetitive imaging,
A method comprising applying constraints on diffracted light intensity and overlapping area information. delete The method according to claim 1,
The calculated phases for the plurality of diffraction patterns are,
Among the initial phase information, the typographic imaging method is input as initial phase information of the subject. The method according to claim 1,
Further comprising the step of reconstructing the surface image of the test object using the last updated information on the test object, typographic imaging method. The method of claim 7,
Information on the last updated subject,
A typographic imaging method used to inspect a mask for an extreme ultraviolet exposure process or a mask to which a pellicle is bonded. Processor; And
Includes a memory for storing at least one instruction executed through the processor,
The at least one command,
An instruction for obtaining a plurality of diffraction patterns by irradiating an inspection probe on an object;
Instructions to calculate phases for the plurality of diffraction patterns;
A command for inputting the calculated phase information as initial phase information for typographic repetitive imaging;
Instructions to perform typographic repetitive imaging; And
Including an instruction to obtain information on at least one of the test object and the inspection light source that are finally updated as a result of the typographic repetitive imaging,
The phase for the plurality of diffraction patterns is,
A typographic imaging apparatus having a characteristic in which the phase of the test object and the phase of the inspection light source are convolved. The method of claim 9,
The phases for the plurality of diffraction patterns are calculated using single shot coherence diffraction imaging (CDI). The method of claim 10,
The single shot coherence diffraction imaging (CDI),
An error reduction algorithm (Error Reduction Algorithm; ERA) or a hybrid input-output (HIO) algorithm performed using a typographic imaging apparatus. The method of claim 9,
The instruction to perform the typographic repetitive imaging,
A typographic imaging apparatus comprising instructions to apply constraints on diffracted light intensity and overlapping area information. delete The method of claim 9,
The calculated phases for the plurality of diffraction patterns are,
Among the initial phase information, the typographic imaging apparatus is input as initial phase information of the subject. The method of claim 9,
The at least one command,
Further comprising a command to reconstruct the surface image of the test subject by using the last updated information on the subject, typographic imaging apparatus. The method of claim 15,
Information on the last updated subject,
Typographic imaging apparatus used to inspect masks for extreme ultraviolet exposure processes or masks to which pellicles are bound. Obtaining a plurality of diffraction patterns by irradiating an inspection probe to the subject;
Calculating phases for the plurality of diffraction patterns;
Inputting the calculated phase information as initial phase information for typographic repetitive imaging;
Performing typographic repetitive imaging; And
Reconstructing a surface image of the subject by using the typographic repetitive imaging result,
The phase for the plurality of diffraction patterns is,
The test object inspection method having a characteristic in which the phase of the test object and the phase of the inspection light source are convolved. The method of claim 17,
The phase for the plurality of diffraction patterns is,
A method for inspecting a subject, calculated using single-shot coherence diffraction imaging (CDI). The method of claim 18,
The single shot coherence diffraction imaging (CDI),
A method of inspecting a subject, which is performed using an Error Reduction Algorithm (ERA) or a Hybrid Input-Output (HIO) algorithm.

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