KR102324622B1 - Process monitoring - Google Patents

Abstract

A method for determining a defect material element, the method comprising: (a) acquiring an electromagnetic emission spectrum of a portion of a defect by a charged particle beam system and by applying a spectroscopy process; (b) acquiring, by a charged particle beam system, a backscattered electron (BSE) image of the region containing the defect; and (c) determining a defective material element. Determination of the defective material element includes: determining whether ambiguity exists in the electromagnetic emission spectrum and, if it is determined that ambiguity exists, resolving the ambiguity based on the BSE image.

Description

Process monitoring {PROCESS MONITORING}

This application claims the benefit of U.S. Application No. 62/778,746, filed December 12, 2018, and U.S. Application No. 16/405,920, filed May 7, 2019, the contents of which are hereby incorporated by reference. Its entirety is incorporated herein.

Particles of nanometer-sized foreign matter may form on wafer substrates, also referred to as bare wafers. These particles are unwanted by-products of the manufacturing process and are considered defects.

The composition of these defects can affect the criticality of these defects.

There is an increasing need to provide an efficient, fast and reliable method for determining the material elements of particles of foreign substances.

A method may be provided for determining a defect material element, the method comprising: acquiring an electromagnetic emission spectrum of a portion of a defect by a charged particle beam system and by applying a spectroscopy process; acquiring, with a charged particle beam system, a backscattered electron (BSE) image of an area that may contain a defect; and determining a defective material element; Determination of the defective material element may include: (a) determining whether ambiguity exists in the electromagnetic emission spectrum, and (b) resolving the ambiguity based on the BSE image if it can be determined that ambiguity exists. can

Resolving the ambiguity may include selecting a defective material element from among potential material elements that exhibit peaks that may be spaced apart from each other by an energy difference that may be lower than the resolution of the spectroscopy process.

Potential material elements may include organic material elements and heavier material elements.

Resolving the ambiguity may include selecting the defect material element based on the intensity of one or more BSE image pixels of the defect.

The region may include a defect and a background material surrounding the defect; The method may include determining a background material element of the background material.

The determination of the defective material element may be based at least in part on the background material element.

The background material element has an atomic weight that may belong to the background atomic weight class, and the determination of the defective material element comprises (a) an intensity parameter of one or more BSE image pixels of the background material and (b) an intensity parameter of one or more BSE image pixels of the defect. determining the atomic weight class of the defective material element based on the relationship between

The method comprises classifying an atomic weight class of the element of defective material into at least one of (a) a grade lighter than the background material grade, (b) a background atomic weight grade, and (d) a grade heavier than the background material grade can do.

The background material may be silicon, and the determination of the defective material element comprises: (a) a second period of the periodic table of the elements, (b) a third period of the periodic table of the elements, (c) a fourth period of the periodic table of the elements, and (d) classifying into classes in the sixth period of the Periodic Table of the Elements.

The method may include determining whether an ambiguity exists in the electromagnetic emission spectrum, and acquiring the BSE image only if the ambiguity exists in the electromagnetic emission spectrum.

Acquisition of the BSE image involves illuminating the area with electrons having incident energy; and substantially generating the BSE image only from BSE electrons having an energy that may be above an energy threshold.

Acquisition of the BSE image may include rejecting BSE electrons originating from locations that may be located below a certain depth from the surface of the region.

A computer readable medium may be provided that may be non-transitory and store instructions that, once executed by the computerized system, cause the computerized system to: by a charged particle beam system and to apply a spectroscopy process. obtaining an electromagnetic emission spectrum of a part of the defect; acquiring, with a charged particle beam system, a backscattered electron (BSE) image of an area that may contain a defect; and determining the defective material element, wherein the determination of the defective material element comprises: (a) determining whether ambiguity exists in the electromagnetic emission spectrum, and (b) the ambiguity exists. This may include resolving the ambiguity based on the BSE image if it can be determined to be present.

A charged particle beam system may be provided, which may include charged particle optics and a processor, the charged particle optics configured to: (i) acquire an electromagnetic emission spectrum of a portion of a defect by applying a spectroscopy process; (ii) acquire a backscattered electron (BSE) image of an area that may contain a defect; The processing circuitry determines the defective material element by (a) determining whether ambiguity exists in the electromagnetic emission spectrum, and (b) resolving the ambiguity based on the BSE image if it can be determined that ambiguity exists. can be configured to

The claimed subject matter considered as the present disclosure is set forth in detail and is expressly claimed in the concluding portion of this specification. BRIEF DESCRIPTION OF THE DRAWINGS The present invention, together with its objects, features, and advantages, both as to a method and arrangement of operation, may be best understood by reference to the following detailed description when read in conjunction with the accompanying drawings. and in the accompanying drawings:
1 illustrates an example of a method for determining a defective material element;
2 illustrates an example of a method for determining a defective material element;
3 illustrates examples of various images of defects comprising multiple elements of defective material;
4 illustrates examples of various BSE (backscattered electron) images;
5 illustrates an example of a charged particle beam system.

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be understood by one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail in order not to obscure the present invention.

The claimed subject matter considered as the present invention is set forth in detail and is expressly claimed in the concluding portion of the specification. BRIEF DESCRIPTION OF THE DRAWINGS The present invention, together with its objects, features, and advantages, both as to a method and arrangement of operation, may be best understood by reference to the following detailed description when read in conjunction with the accompanying drawings. have.

It will be understood that, for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Additionally, where deemed appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

The illustrated embodiments of the present invention may be implemented using mostly electronic components and circuits known to those skilled in the art, thus obscuring the teachings of the present invention and for the understanding and appreciation of the underlying concepts of the present invention. In order not to cause or obscure, details will not be set forth to any greater extent than is considered necessary as illustrated above.

Any reference herein to a method should be applied, mutatis mutandis, to a system capable of executing the method, with the necessary modifications being non-transitory to a computer-readable medium storing instructions for carrying out the method. should be applied

Any reference herein to a system, mutatis mutandis, applies to a method that can be executed by the system, mutatis mutandis, a computer-readable medium storing instructions that are non-transitory and executable by the system. should be applied to

Any reference in this specification to a non-transitory computer-readable medium shall, with the necessary modifications, apply to a method that can be applied when executing instructions stored on the computer-readable medium, with the necessary modifications, to the computer-readable medium. It should apply to systems configured to execute instructions stored in .

Resolving the ambiguity:

Systems, methods, and computer readable media for process monitoring may be provided.

A particle of foreign material (hereinafter, a defect) may be made of one or more defective material elements. A defect material element is a material element belonging to a defect.

The electromagnetic emission spectrum of a portion of the defect can be generated by applying a spectroscopy process.

The electromagnetic emission spectrum may provide an indication of one or more defective material elements.

Nevertheless, spectroscopy processes may have certain resolutions. Accordingly, ambiguities may exist in the electromagnetic emission spectrum. Such ambiguity exists when the energy difference between the peaks (associated with different material elements) is less than the resolution of the spectroscopy process.

For example, the resolution of the spectroscopy process can be about 80 to 90 electron volts, and the spectroscopy process can be performed on lighter material elements and heavier material elements, such as:

a. either the lighter material element silicon (Si) and the heavier elements tantalum (Ta) or tungsten (W);

b. the lighter material elemental nitrogen (N) and the heavier element titanium (Ti);

c. either the lighter material element oxygen (O) and the heavier elements vanadium (V) or chromium (Cr);

d. the lighter element element fluorine (F) and the heavier element iron (Fe);

e. the lighter element element sodium (Na) and the heavier element zinc (Zn);

f. The lighter material element phosphorus (P) and the heavier element zirconium (Zr)

cannot distinguish the members of the sets of

The lighter material elements may be non-metallic and the heavier material elements may be metallic, although this is not necessarily the case. For example, germanium is quite heavy but not metallic.

Examples of such ambiguities are illustrated in Table 1. In Table 1, each row contains a set of material elements that exhibit energy peaks that are spaced from each other by an energy difference smaller than the resolution of the spectroscopy process. It should be noted that different ambiguities may arise when applying different landing energies.

lighter material elements heavier material elements Si Ta, W N Ti O V, Cr F Fe Na Zn P Zr

It has been found that backscattered electron (BSE) images can help resolve ambiguities and determine which defective material elements appear in the electromagnetic emission spectrum. A crystal may accurately represent an exact material element, or it may provide a rough classification into one of a number of classes of material elements.

Referring to Table 1 for each of the above-mentioned sets, the intensity (eg, gradation) of the BSE image pixels of any one of the lighter material elements of the above-mentioned set is the substantially different from the intensity of the BSE image pixels of the heavier material elements of the set (eg, by at least 10%, 20%, 30%, etc.).

Referring to the first row of Table 1, the intensity of the BSE image pixels of Si is substantially different from the intensity of the BSE image pixels of Ta or W.

These intensity differences, alone or in combination with additional information that can be obtained from BSE images and electromagnetic emission spectra, can be used to resolve ambiguity.

Additional information may relate to background material that may surround the defect. Since at least some of the BSE electrons in the BSE image are expected to be extracted from the background material that may be located below the defect, the material element of the background material can be identified from the electromagnetic emission spectrum of the portion of the defect.

The background material is generally known in advance. However, even if the background material is not known in advance, the background material can be learned from the electromagnetic emission spectrum. And, the relationship between the BSE image pixels of the background material and the BSE image pixels of the defect may be used to determine the relationship between the atomic weight of the defective material element and the atomic weight of the background material element.

For example, if the electromagnetic emission spectrum illustrates that the background material is aluminum (Al) and the BSE image pixels of the defect are much brighter (stronger intensity) than the BSE image pixels of the background material, then the defect is an element heavier than aluminum. include those If the defect is brighter than the background Si and the defect contains a peak of Si or Ta or W in the electromagnetic spectrum, the defect contains Ta or W.

For example, if the electromagnetic emission spectrum illustrates that the background material is not Al and the background material is Si, and if the BSE image pixels of the defect are much brighter (stronger intensity) than the BSE image pixels of the background material, then the defect Silver contains elements heavier than aluminum. Thus, if the electromagnetic spectrum contains F or Fe, the defect contains Fe.

The text below illustrates various methods. For brevity of description, each method is illustrated with reference to a single defective material element and to a single ambiguity.

It should be noted that each method can be applied to each defective material element among a plurality of defective material elements and can resolve a number of ambiguities.

For example, an electromagnetic emission spectrum may contain multiple ambiguities, and each method may resolve each ambiguity.

1 illustrates an example of a method 100 for determining a defective material element. Method 100 includes one or more graphics processing units, one or more central processing units (CPUs), one or more image processors, and/or one or more other integrated circuits, such as application specific integrated circuits (ASICs), field programmable gate arrays ( FPGA), a fully custom integrated circuit, or the like, or processing logic, such as processing circuitry, which may include a combination of such integrated circuits.

The method 100 may begin, at step 110 , by acquiring an electromagnetic emission spectrum of a portion of the defect by a charged particle beam system and by applying a spectroscopic process. A charged particle beam system is a system that obtains information about an object by illuminating the object with one or more charged particle beams and collecting particles and/or photons emitted from the object. Analysis of the detected particles may be done by processing circuitry of the charged particle beam system, by one or more processing circuitry located external to the tool, or a combination of both.

Step 110 may include illuminating a portion of the defect with one or more electron beams and collecting charged particles, such as x-rays. X-rays may be collected during energy dispersive spectroscopy (EDX).

Step 110 may be followed by step 120 of acquiring a backscattered electron (BSE) image of the region containing the defect by a charged particle beam system.

Step 120 may be followed by step 130 of determining the defective material element by a spectroscopy process. Step 120 is based on the results of steps 110 and 120 (using EDX).

Step 130 may include steps 132 and 140 .

Step 132 determines whether ambiguity exists in the electromagnetic emission spectrum (if there are overlapping electromagnetic emission readings) if the energy difference between the peaks (associated with different material elements) is less than the resolution of the spectroscopy process. may include doing

If the answer is yes, skip to step 140 of resolving ambiguity based on the BSE image: the information provided by the BSE image is used to distinguish materials with overlapping electromagnetic emission readings. The result of step 140 is an electromagnetic emission spectrum without ambiguity.

If the answer is no, step 130 ends.

Step 140 may include selecting a defective material element from among potential material elements that exhibit peaks spaced apart from each other by an energy difference lower than the resolution of the spectroscopy process. A material with known overlapping electromagnetic emission readings can be observed. Each row of Table 1 is an example of such a potential material element.

For example, step 140 may include selecting a material element from (i) from F and Fe, or (ii) from P and Zr, or (iii) from N and Ti, or (iv) from O and V or Cr. may include

Step 140 may include selecting a defective material element based on an intensity of one or more BSE image pixels of the defect.

Step 140 may be based, at least in part, on the background material element. The region (imaged during step 120 ) may include defects and background material surrounding the defects. Step 140 may include determining a background material element of the background material.

Background material elements have atomic weights belonging to the background atomic weight classes (periods of the periodic table). Step 140 comprises determining an atomic weight class of the defective material element based on a relationship between (a) an intensity parameter of one or more BSE image pixels of the background material and (b) an intensity parameter of one or more BSE image pixels of the defect. may include

Brighter BSE image pixels exhibit a higher atomic weight while darker BSE pixels exhibit a lower atomic weight.

Step 140 includes classifying the atomic weight class of the defective material element into at least one of (a) a lighter than the background material grade, (b) a background atomic weight grade, and (d) a heavier than the background material grade. may include steps.

For example, the defective material element is:

● Second period of the Periodic Table of the Elements (eg N, O or F)

● Third Period of the Periodic Table of the Elements (eg Si, P or Na)

● Fourth Period of the Periodic Table of the Elements (eg Ti, V, Cr, Fe or Zn)

● 5th period of the periodic table (eg Zr)

● Period 6 of the Periodic Table of the Elements (eg Ta or W)

It can be classified (according to the intensity of the BSE image pixels) into a middle class.

As another example, the defective material element is:

q Lighter grade than the substrate - eg the second period of the periodic table of the elements (eg N, O or F)

● Same grade as substrate - eg 3rd period of the Periodic Table of the Elements (eg Si, P or Na)

● Grades heavier than the substrate - eg 4th, 5th or 6th period of the Periodic Table of the Elements (eg Ti, V, Cr, Fe, or Zn, Zr, Ta or W)

It can be classified (according to the intensity of the BSE image pixels) into a middle class.

The result of step 130 may be a determination of one or more defective material elements. The crystal can be presented as an apparent electromagnetic emission spectrum of a portion of the defect.

Step 130 may be followed by step 150 responding to the result of step 130 . For example, step 150 may include generating and/or transmitting an alert or indication relating to one or more material elements of the defect, storing the unambiguous electromagnetic emission spectrum, storing the alert or indication, different parameters performing other spectroscopy processes and/or acquiring other BSE images, etc. For example, another spectroscopy process may be run with higher landing voltages to see material elements that are difficult to see in previous spectroscopy process iterations. For example, step 120 may involve applying a relatively low kV EDX to keep the interaction volume small and sensitivity high. However, some elements, especially Ti, are difficult to see at low kV (overlapping peaks near 400 V). Therefore, if steps 120-140 find N or Ti at 3 kV, another EDX process is run at a higher kV (approximately 6 kV), in which case there is an additional Ti peak (4.5 kV). If there is a 4.5 kV peak, then Ti is present. If not visible, it is N.

Assume, for example, that the presence of defects with heavier material elements is more problematic than the presence of defects with lighter material elements. Under this assumption, the presence of a heavier defective material element can trigger a more influential response compared to the response triggered by a lighter defective material element.

The response may include disqualifying the wafer, determining that the wafer or die is eligible despite the defect, reassessing the manufacturing process, and the like.

2 illustrates a method 102 for determining a defective material element.

Method 102 may begin with step 112 of acquiring an electromagnetic emission spectrum of a portion of a defect by means of a charged particle beam system and by applying a spectroscopy process.

Step 112 may include illuminating a portion of the defect with one or more charged electron beams and collecting charged particles, such as x-rays. X-rays may be collected during energy dispersive spectroscopy (EDX).

For brevity of explanation, step 112 is assumed to involve applying an EDX process.

Step 112 may be followed by step 115 of determining whether an ambiguity exists in the electromagnetic emission spectrum.

If there is no ambiguity, step 115 may be followed by step 152 .

If there is an ambiguity (or more than one ambiguity), step 115 is followed by step 122 of acquiring, by a charged particle beam system, a BSE image of the region containing the defect.

Step 122 may be followed by step 142 of resolving the ambiguity based on the BSE image.

Step 142 may be followed by step 152 of responding to the result of at least one of steps 112 and 142 .

In method 102 , BSE images are only acquired (at 122 ) in response to determination of ambiguity present in the electromagnetic emission spectrum ( at 115 ). Method 110 differs from method 112 because BSE images are acquired (at step 120) before determining whether ambiguity exists in the electromagnetic emission spectrum (at step 132). In the method 112 , fewer BSE images may be acquired compared to the number of BSE images acquired in the method 110 , so that the overall duration of the method 112 is less than the duration of the method 110 . could be shorter.

3 illustrates examples of various BSE images 202-208 of defects, acquired by a charged particle beam, according to method 110 or 112 . The defects shown in the images contain multiple defective material elements.

BSE image 202 illustrates a defect 210 comprising multiple elements of defective material. BSE image 204 illustrates the edges of the defect. BSE image 206 illustrates a region containing defect 210 surrounded by silicon background material 216 . Defect 210 includes a heavier material element 214 and a lighter material element 212 . Composite image 208 colors different defective material elements with different colors.

It should be noted that any of the methods mentioned above may be modified and acquisition of one or more BSE images may be performed without checking for the presence of ambiguity.

It should be noted that any of the methods mentioned above may or may not include generating a modified EDX spectrum that takes into account the ambiguities resolved (if ambiguities exist).

Surface information:

Acquisition of the BSE image of the region containing the defect comprises illuminating the region with a beam of charged particles having a landing energy, thereby causing BSE electrons to be emitted from the sample, and detecting at least some of the BSE electrons by a BSE detector. include that

BSE electrons emitted from the sample can originate from the surface of the region as well as from different depths within the sample.

For example, at a landing energy of several kilovolts, most of the BSE electrons forming the BSE image are well emitted under unburied defects, eg, foreign particles.

BSE emitted from depths exceeding the depth threshold, collecting BSE electrons from the surface (and possibly up to the depth threshold), in cases where the defects are not buried defects or are at least located mostly above the surface of the sample. It may be advantageous to reject (not detect) electrons.

This can be done using low-loss BSE imaging. Low-loss BSE spectroscopy uses energy filtering and involves rejecting BSE electrons with energy below an energy threshold. The energy threshold may be set to be substantially equal to the incident energy. For example, the energy threshold may be equal to about 60-99% of the incident energy. Thus, for a landing energy of 2 kV, the energy threshold may be between 1.5 kV and 1.95 kV. Other energy thresholds may apply.

This will cause the BSE image to be formed mainly from BSE electrons with energy above the energy threshold.

Energy filtering reduces the amount of BSE electrons reaching the BSE filter, but better represents the material elements of the defect than the material of the substrate. This may be especially true for defects smaller than 100 nm.

Accordingly, step 120 of any of methods 100 and 102 may include acquiring low loss BSE images.

BSE images 300 , 302 , 304 , 306 , 308 and 310 of FIG. 4 illustrate BSE images of an area including defect 312 . BSE images 302 , 304 , 306 , 308 and 310 are acquired while applying different energy filters. BSE images 308 and 310 are acquired using a beam landing energy of 2 kV and energy filters between 1.5 kV and 1.8 kV. It can be seen that the BSE image 300 is formed primarily of BSE electrons emitted from the background material under the defect 312 , which means that the BSE image pixels of the defect 312 are the BSE image pixels of the background material 316 . because it has a very similar strength to

On the other hand, the BSE images 308 and 310 clearly show that the defect 312 contains a high impedance (high Z) defect material element 316 and a low Z defect material element 318, both of which are in the background. well distinguished from the substance.

5 illustrates an object 440 and a charged particle beam system 400 .

Charged particle beam system 400 may include charged particle optics and a processor. Charged particle beam system 400 may be configured to perform at least one of methods 100 and 102 .

In FIG. 5 , the charged particle optics are illustrated as including an EDS detector 414 for detecting x-ray particles 426 and a charged particle column 402 .

Charged particle column 402 includes beam source 404 for outputting charged particle beam 420 , BSE detector 408 for detecting BSE electrons 422 , and BSE electrons reaching BSE detector 408 . It includes an energy filter 410 to filter out BSE electrons before doing so. 5 also illustrates a secondary electron detector 406 for detecting secondary electrons 424 .

The charged particle optics (i) obtain an electromagnetic emission spectrum of a portion of the defect by applying a spectroscopy process (by illuminating the object with a charged particle beam 420 and detecting x-ray particles by an EDS detector 414) and ; and (ii) acquiring a backscattered electron (BSE) image of the region containing the defect.

The processing circuit 412 is configured to (a) determine whether an ambiguity exists in the electromagnetic emission spectrum, and (b) if it is determined that an ambiguity exists, resolve the ambiguity based on the BSE image. can be configured to determine

It should be noted that the charged particle beam system 400 may have other configurations. For example, the charged particle beam system 400 may include an AES detector in place of or in addition to an EDS detector, there may be multiple BSE detectors, there may be any spatial relationship between the column and the EDS detector, and , the BSE detector may be located elsewhere, the angle of illumination may not be perpendicular to the object, the charged particle beam system 400 may have no secondary electron detector, any of the beams shown in FIG. It may be deflected and/or manipulated in undesired ways, and there may be additional optical elements, such as condensing lenses or any other optical lens or element.

5 also illustrates defect 444 and region 442 below defect 444, from which BSE electrons may be emitted.

In the foregoing specification, the present invention has been described with reference to specific examples of embodiments of the present invention. However, it will be apparent that various modifications and changes may be made therein without departing from the broader spirit and scope of the invention as recited in the appended claims.

Moreover, the terms "front", "behind", "top", "bottom", "above", "below", etc. in the description and claims, where present, are used for descriptive purposes and necessarily have a permanent relative position It's not meant to explain them. It is understood that the terms so used are interchangeable under appropriate circumstances such that embodiments of the invention described herein may, for example, operate in other orientations than those illustrated or otherwise described herein. do.

Connections as discussed herein may be any type of connection suitable for passing signals to or from respective nodes, units or devices, eg, via intermediate devices. Accordingly, unless otherwise implied or stated, connections may be, for example, direct connections or indirect connections. Connections may be illustrated or described with respect to being a single connection, a plurality of connections, unidirectional connections, or bidirectional connections. However, different embodiments may change the implementation of the connections. For example, individual unidirectional connections may be used instead of bidirectional connections, and vice versa. Also, the plurality of connections may be replaced with a single connection that carries multiple signals continuously or in a time multiplexed manner. Similarly, single connections carrying multiple signals may be split into a variety of different connections carrying subsets of these signals. Therefore, there are many options for conveying signals.

Any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality is achieved. Thus, any two components herein combined to achieve a particular functionality, regardless of architectures or intermediate components, may be viewed as “associated with” each other such that the desired functionality is achieved. Similarly, any two components so associated can also be viewed as “operably connected” or “operably coupled” to each other to achieve desired functionality.

Moreover, those skilled in the art will recognize that the boundaries between the operations described above are exemplary only. Multiple operations may be combined into a single operation, the single operation may be distributed into additional operations, and the operations may be executed at least partially overlapping in time. Moreover, alternative embodiments may include multiple instances of a particular act, and in various other embodiments, the order of acts may be changed.

Also, for example, in one embodiment, the illustrated examples may be implemented as circuitry located in the same device or on a single integrated circuit. Alternatively, examples may be implemented as any number of separate integrated circuits, or individual devices interconnected to each other in a suitable manner.

However, other modifications, variations and alternatives are also possible. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word 'comprising' does not exclude the presence of elements or steps other than those recited in a claim. Moreover, the terms “a” or “an” as used herein are defined as one or more than one. Also, the use of introductory phrases such as "at least one" and "one or more" in the claims is singular, even when the same claim includes the introductory phrases "one or more" or "at least one" and the singular terms. The introduction of another claim element by terms should not be construed as implying that any particular claim incorporating such introduced claim element is limited to inventions incorporating only one such element. The same applies to the use of "above". Unless otherwise stated, terms such as "first" and "second" are used to arbitrarily distinguish between the elements they describe. Accordingly, these terms are not necessarily intended to indicate a temporal or other prioritization of such elements. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of such measures cannot be used to obtain advantage.

While specific features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and variations that fall within the true spirit of the present invention.

Claims (14)

A method for determining a defective material element of a defect, comprising:
acquiring an electromagnetic emission spectrum of a portion of the defect by means of a charged particle beam system and by applying a spectroscopy process;
acquiring, by the charged particle beam system, a backscattered electron (BSE) image of the region containing the defect; and
determining whether an ambiguity exists in the electromagnetic emission spectrum and in response to determining that an ambiguity exists, determining the defective material element by resolving the ambiguity based on the BSE image;
wherein acquiring the BSE image comprises illuminating the region with electrons having an incident energy and generating the BSE image only from BSE electrons having an energy above an energy threshold. method to determine. According to claim 1,
Resolving the ambiguity comprises selecting the defective material element from among potential material elements exhibiting peaks spaced apart from each other by an energy difference lower than the resolution of the spectroscopy process. Way. 3. The method of claim 2,
wherein the potential material elements include organic material elements and heavier material elements. According to claim 1,
and resolving the ambiguity comprises selecting the defective material element based on an intensity of one or more BSE image pixels of the defect. According to claim 1,
wherein the region comprises the defect and a background material surrounding the defect, the method comprising determining a background material element of the background material. 6. The method of claim 5,
wherein the determining the defective material element is based on the background material element. 7. The method of claim 6,
The background material element has an atomic weight belonging to the background atomic weight class, and determining the defective material element comprises: (a) an intensity parameter of one or more BSE image pixels of the background material; and (b) one or more BSE images of the defect. A method for determining a defective material element of a defect, comprising determining an atomic weight class of the defective material element based on a relationship between the intensity parameters of the pixel. 8. The method of claim 7,
classify the atomic weight grade of the defective material element into one of at least one of (a) a grade lighter than the background material grade, (b) the background atomic weight grade, and (d) a grade heavier than the background material grade A method for determining a defect material element of a defect comprising the step of: A method for determining a defective material element of a defect, comprising:
acquiring an electromagnetic emission spectrum of a portion of the defect by means of a charged particle beam system and by applying a spectroscopy process;
acquiring, by the charged particle beam system, a backscattered electron (BSE) image of the region containing the defect; and
determining whether an ambiguity exists in the electromagnetic emission spectrum and in response to determining that an ambiguity exists, determining the defective material element by resolving the ambiguity based on the BSE image;
the region includes the defect and a background material surrounding the defect, the method comprising determining a background material element of the background material;
The background material is silicon, and the determination of the defective material element comprises: (a) a second period of the periodic table of the elements, (b) a third period of the periodic table of the elements, (c) a fourth period of the periodic table of the elements; and (d) classifying into a class during a sixth period of the Periodic Table of the Elements. According to claim 1,
determining whether the ambiguity exists in the electromagnetic emission spectrum, and acquiring the BSE image in response to the ambiguity present in the electromagnetic emission spectrum. . delete A method for determining a defective material element of a defect, comprising:
acquiring an electromagnetic emission spectrum of a portion of the defect by means of a charged particle beam system and by applying a spectroscopy process;
acquiring, by the charged particle beam system, a backscattered electron (BSE) image of the region containing the defect; and
determining whether an ambiguity exists in the electromagnetic emission spectrum and in response to determining that an ambiguity exists, determining the defective material element by resolving the ambiguity based on the BSE image;
wherein acquiring the BSE image comprises rejecting BSE electrons originating from locations located below a specific depth from the surface of the region. A non-transitory computer-readable medium containing instructions, comprising:
The instructions, when executed by a processor, cause the processor to:
acquiring the electromagnetic emission spectrum of a portion of the defect;
acquiring a backscattered electron (BSE) image of the region containing the defect; and
determining whether an ambiguity exists in the electromagnetic emission spectrum and in response to determining that an ambiguity exists, determining a defective material element by resolving the ambiguity based on the BSE image;
Acquiring the BSE image comprises illuminating the region with electrons having an incident energy and generating the BSE image only from BSE electrons having an energy above an energy threshold. . A charged particle beam system comprising charged particle optics and a processor, the system comprising:
The processor is:
acquiring an electromagnetic emission spectrum of a part of the defect by applying a spectroscopy process;
acquiring a backscattered electron (BSE) image of the region containing the defect;
determine whether an ambiguity exists in the electromagnetic emission spectrum and, in response to determining that an ambiguity exists, determine a defective material element by resolving the ambiguity based on the BSE image,
and acquiring the BSE image comprises illuminating the region with electrons having an incident energy and generating the BSE image only from BSE electrons having an energy above an energy threshold.

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