CN110596157A - Method and device for measuring nitrogen content in semiconductor structure - Google Patents
Method and device for measuring nitrogen content in semiconductor structure Download PDFInfo
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- CN110596157A CN110596157A CN201910891813.7A CN201910891813A CN110596157A CN 110596157 A CN110596157 A CN 110596157A CN 201910891813 A CN201910891813 A CN 201910891813A CN 110596157 A CN110596157 A CN 110596157A
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Abstract
The invention relates to a method for measuring nitrogen content in a semiconductor structure, which comprises the following steps: providing a semiconductor structure, wherein the semiconductor structure comprises a charge trapping layer and a tunneling layer formed on the charge trapping layer; scanning the semiconductor structure to obtain a nitrogen content electron energy loss map of the semiconductor structure; wherein the incident electron beam forms a first extended region at the bottom of the charge trapping layer in a first acquisition region and a second extended region at the bottom of the charge trapping layer in a second acquisition region adjacent to the first acquisition region, the first extended region and the second extended region being at least non-overlapping; and determining the nitrogen content in the charge trapping layer and the tunneling layer according to the nitrogen content electron energy loss map.
Description
Technical Field
The invention mainly relates to the field of semiconductor testing, in particular to a method for measuring nitrogen content in a semiconductor structure.
Background
Semiconductor integrated circuits have since their birth, undergone a phase of development from small-scale, medium-scale to large-scale and very large-scale integration, and are increasingly becoming one of the most active technical fields in modern scientific technology.
To overcome the limitations of conventional two-dimensional memories in terms of storage capacity, etc., three-dimensional (3D) stacking techniques are often employed to achieve higher performance and integration of the memory. The three-dimensional stacking technology can form three-dimensional structures with three-dimensional integration and signal communication in the vertical direction by micro-machining technologies such as stacking, hole interconnection and the like for chips or structures with different functions. The three-dimensional arrangement of memory cells over a substrate using this technique can greatly increase the memory density of a memory chip.
Semiconductor stack (stack) structures have been widely used in the fabrication of 3D memory chips. For example, the multi-layer structure of SiOx-SiOxNx-SiOxNy stack (ONO stack) is often the core structure of non-volatile three-dimensional memory chips such as 3D NAND, and the variation of the composition and thickness thereof greatly affects the programming, storing and reading capabilities of the chip. In an ONO stack structure, the nitrogen (N) content distribution is a very critical composition indicator. Since the content of nitrogen can significantly affect the electrical properties of the multilayer structure, it is important to accurately measure the nitrogen content in the semiconductor structure.
The instruments and methods for analyzing the elemental content are mainly Secondary Ion Mass Spectrometry (SIMS), X-ray Photoelectron Spectroscopy (XPS), Energy Spectrometer (EDS), and Electron Energy Loss Spectroscopy (EELS).
The thickness of the ONO stack structure is typically less than 20 nanometers (nm), and the diameter of the channel aperture surrounded by the ONO stack structure is less than 150 nm. The detection area of secondary ion mass spectrometry and X-ray photoelectron spectroscopy is in a micrometer scale, and cannot be applied to element analysis in devices such as 3D NAND memory chips. The quantitative analysis of the energy spectrometer is influenced by small signal quantity, signal absorption (especially obvious light element signal absorption) of a sample, secondary fluorescence interference and the like, and the accuracy and precision of a measurement result cannot meet the requirements. The electronic energy loss map has the characteristics of large signal quantity and small signal interference, and has wide application prospects in qualitative and quantitative analysis of elements.
The difficulty of quantitative characterization of electron energy loss maps of nitrogen elements in an ONO stack structure is that the precision of measurement results is greatly influenced by irradiation damage of the structure caused by high-energy incident electron beams. This radiation damage results primarily from ionization damage of the silicon nitride in the ONO stack structure. The prior literature (Igor Levin et al applied Physics Letters 83,1548(2003)) mentions that radiation damage causes diffusion of nitrogen elements towards the interface of the ONO stack thin film (film), and also suggests that reducing the sampling time and increasing the collection efficiency may reduce radiation damage without giving a high accuracy result of the nitrogen content distribution in the ONO stack structure.
Disclosure of Invention
The invention aims to provide a method for measuring the nitrogen content in a semiconductor structure, which can effectively improve the measurement precision of the nitrogen content in the semiconductor structure.
In order to solve the above technical problem, the present invention provides a method for measuring nitrogen content in a semiconductor structure, comprising: providing a semiconductor structure comprising a charge trapping layer and a tunneling layer formed over the charge trapping layer; scanning the semiconductor structure to obtain a nitrogen content electron energy loss map of the semiconductor structure; wherein the incident electron beam forms a first extended region at the bottom of the charge trapping layer in a first acquisition region and a second extended region at the bottom of the charge trapping layer in a second acquisition region adjacent to the first acquisition region, the first extended region and the second extended region having at least no overlap; and determining the nitrogen content in the charge trapping layer and the tunneling layer according to the nitrogen content electron energy loss map.
In an embodiment of the present invention, all acquisition regions of the semiconductor structure are scanned in fixed steps.
In one embodiment of the present invention, the semiconductor structures are scanned row-by-row or column-by-column from the same end.
In one embodiment of the present invention, the semiconductor structure is scanned row-by-row or column-by-column in a zigzag fashion.
In an embodiment of the present invention, the acquisition regions in the same row or column of the semiconductor structure are scanned in a fixed step.
In an embodiment of the present invention, the acquisition region in the nth row or nth column is scanned with a first fixed step size, and the acquisition region in the (N + 1) th row or (N + 1) th column is scanned with a second fixed step size, where the second fixed step size is not smaller than the second fixed step size, where N is a positive integer.
In an embodiment of the present invention, a peak value of the nitrogen content in the nitrogen content electron energy loss map is read as the nitrogen content in the charge trapping layer and the tunneling layer.
In an embodiment of the present invention, an average of the nitrogen contents in the nitrogen content electron energy loss map is read as the nitrogen content in the charge trapping layer and the tunneling layer.
In an embodiment of the invention, the step size is 1.22-1.83 nm.
Another aspect of the present invention provides a device for measuring nitrogen content in a semiconductor structure, the semiconductor structure including a charge trapping layer and a tunneling layer formed over the charge trapping layer, the device comprising: a transmission electron microscope adapted to scan the semiconductor structure to obtain a nitrogen content electron energy loss map of the semiconductor structure; wherein the incident electron beam forms a first extended region at the bottom of the charge trapping layer in a first acquisition region and a second extended region at the bottom of the charge trapping layer in a second acquisition region adjacent to the first acquisition region, the first extended region and the second extended region having at least no overlap; a platform adapted to determine nitrogen content in the charge trapping layer and the tunneling layer from the nitrogen content electron energy loss map.
Compared with the prior art, the invention has the following advantages: according to the method for measuring the nitrogen content in the semiconductor structure, the incident electron beams form at least non-overlapping first extension regions and second extension regions at the bottoms of the charge trapping layers in the adjacent first collection regions and second collection regions respectively, so that the influence of the incident electron beams on the semiconductor structure is remarkably reduced, and the measurement precision of the nitrogen content in the semiconductor structure can be effectively improved.
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In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below, wherein:
FIG. 1 is a flow chart of a method for measuring nitrogen content in a semiconductor structure in accordance with one embodiment of the present invention;
FIG. 2A is a schematic cross-sectional view of a semiconductor structure illustrating a method for measuring nitrogen content in the semiconductor structure in accordance with one embodiment of the present invention;
FIG. 2B is a cross-sectional TEM image of the semiconductor structure according to the method for measuring the nitrogen content in the semiconductor structure of the present invention;
FIG. 3 is a schematic diagram of a scanning semiconductor structure for a method of measuring nitrogen content in a semiconductor structure in accordance with one embodiment of the present invention;
FIG. 4 is a schematic illustration of a first extension region and a second extension region of a method of measuring nitrogen content in a semiconductor structure in accordance with one embodiment of the present invention;
FIG. 5 is a scanning diagram of a method for measuring nitrogen content in a semiconductor structure according to an embodiment of the present invention, wherein the step size is 0.7 nm;
FIG. 6 is a schematic scanning diagram of a method for measuring nitrogen content in a semiconductor structure with a step size of 1.22nm according to an embodiment of the present invention;
FIG. 7A is a pre-scan imaging plot at a step size of 0.7nm for a method of measuring nitrogen content in a semiconductor structure in accordance with one embodiment of the present invention;
FIG. 7B is a graph of an image of a semiconductor structure after scanning with a step size of 0.7 nm;
FIG. 8A is a graph of pre-scan imaging at a step size of 1.22nm for a method of measuring nitrogen content in a semiconductor structure in accordance with one embodiment of the present invention;
FIG. 8B is a graph of an image of a semiconductor structure after scanning with a step size of 1.22 nm;
FIG. 9 is a nitrogen content electron energy loss map of a semiconductor structure for a method of measuring nitrogen content in a semiconductor structure in accordance with one embodiment of the present invention;
FIG. 10 is a nitrogen content electron energy loss map of a semiconductor structure at different durations of a method of measuring nitrogen content in the semiconductor structure, in accordance with an embodiment of the present invention.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described herein, and thus the present invention is not limited to the specific embodiments disclosed below.
As used in this application and the appended claims, the terms "a," "an," "the," and/or "the" are not intended to be inclusive in the singular, but rather are intended to be inclusive in the plural unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that steps and elements are included which are explicitly identified, that the steps and elements do not form an exclusive list, and that a method or apparatus may include other steps or elements.
In describing the embodiments of the present invention in detail, the cross-sectional views illustrating the structure of the device are not enlarged partially in a general scale for convenience of illustration, and the schematic drawings are only examples, which should not limit the scope of the present invention. In addition, the three-dimensional dimensions of length, width and depth should be included in the actual fabrication.
For convenience in description, spatial relational terms such as "below," "beneath," "below," "under," "over," "upper," and the like may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that these terms of spatial relationship are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary words "below" and "beneath" can encompass both an orientation of up and down. The device may have other orientations (rotated 90 degrees or at other orientations) and the spatial relationship descriptors used herein should be interpreted accordingly. Further, it will also be understood that when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.
In the context of this application, a structure described as having a first feature "on" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed in between the first and second features, such that the first and second features may not be in direct contact.
It will be understood that when an element is referred to as being "on," "connected to," "coupled to" or "contacting" another element, it can be directly on, connected or coupled to, or contacting the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly on," "directly connected to," "directly coupled to" or "directly contacting" another element, there are no intervening elements present. Similarly, when a first component is said to be "in electrical contact with" or "electrically coupled to" a second component, there is an electrical path between the first component and the second component that allows current to flow. The electrical path may include capacitors, coupled inductors, and/or other components that allow current to flow even without direct contact between the conductive components.
The invention provides a method for measuring nitrogen content in a semiconductor structure, which can effectively improve the measurement precision of the nitrogen content in the semiconductor structure.
The method for measuring the nitrogen content in the semiconductor structure comprises the following steps: providing a semiconductor structure comprising a charge trapping layer and a tunneling layer formed over the charge trapping layer; scanning the semiconductor structure to obtain a nitrogen content electron energy loss map of the semiconductor structure, wherein the incident electron beam forms a first extended region at the bottom of the charge trapping layer in a first acquisition region and a second extended region at the bottom of the charge trapping layer in a second acquisition region adjacent to the first acquisition region, the first extended region and the second extended region being at least non-overlapping; and determining the nitrogen content in the charge trapping layer and the tunneling layer according to the nitrogen content electron energy loss map.
Fig. 1 is a flow chart of a method for measuring nitrogen content in a semiconductor structure according to an embodiment of the invention. The method for measuring the nitrogen content in the semiconductor structure is described in detail below with reference to fig. 1. It is to be understood that the following description is merely exemplary, and that various changes may be made by those skilled in the art without departing from the spirit of the invention.
Step 110 provides a semiconductor structure. The semiconductor structure includes a charge trapping layer and a tunneling layer formed over the charge trapping layer.
Fig. 2A is a cross-sectional view of a semiconductor structure illustrating a method for measuring nitrogen content in the semiconductor structure according to an embodiment of the invention. FIG. 2B is a transmission electron microscope image of a cross-section of a semiconductor structure illustrating a method for measuring nitrogen content in the semiconductor structure, in accordance with one embodiment of the present invention.
Referring to fig. 2A and 2B, in an embodiment of the invention, the semiconductor structure 200 may include a charge trapping layer (Trap layer)202 and a tunneling layer (Tunnel layer)203 formed on the charge trapping layer 202.
In an embodiment of the present invention, the charge trapping Layer 202 and the tunneling Layer 203 may be grown on a single crystal silicon (Si) Substrate (Substrate)201, respectively, using an Atomic Layer Deposition (ALD) growth process. In some examples, the semiconductor structure 200 further includes a polysilicon layer (Poly Si layer)204 over the tunneling layer 203 and a protection layer (protection layer)205 over the polysilicon layer 201. Illustratively, the polysilicon layer 204 may be formed over the tunneling layer 203 using an atomic layer deposition growth process. The protection layer 205 may be an amorphous carbon layer, but the embodiment is not limited thereto.
In an embodiment of the present invention, the semiconductor structure 200 may be fabricated using a Focused Ion Beam (FIB). Illustratively, the thickness of the semiconductor structure 200 may be 50-80 nm.
Step 120, scanning the semiconductor structure to obtain a nitrogen content electron energy loss map of the semiconductor structure. Wherein the incident electron beam forms a first extended region at the bottom of the charge trapping layer in a first acquisition region and a second extended region at the bottom of the charge trapping layer in a second acquisition region adjacent to the first acquisition region, the first extended region and the second extended region being at least non-overlapping.
FIG. 3 is a schematic diagram of a scanning semiconductor structure for a method of measuring nitrogen content in a semiconductor structure according to an embodiment of the present invention. Referring to fig. 3, the diameter of each acquisition region (shown as a square grid) in the semiconductor structure 300 is a step size. In an embodiment of the present invention, all acquisition regions of the semiconductor structure 300 may be scanned in fixed steps. The nitrogen content electron energy loss spectra of all the collection regions are integrated to form the nitrogen content electron energy loss spectrum of the semiconductor structure 300.
In an embodiment of the present invention, the semiconductor structure 300 may be scanned row-by-row or column-by-column from the same end. In one example shown in fig. 3, the semiconductor structure 300 is scanned line by line with the acquisition region 301 as an end point. In some examples, the acquisition regions of the same row or column in the semiconductor structure 300 may be scanned in fixed steps. In other examples, the acquisition region of row N or column N may also be scanned at a first fixed step size and the acquisition region of row N +1 or column N +1 may also be scanned at a second fixed step size. And the second fixed step length is not less than the second fixed step length, and N is a positive integer.
In another embodiment of the present invention, the semiconductor structure 300 may be scanned row-by-row or column-by-column in a zigzag fashion. Illustratively, the acquisition regions of the same row or column in the semiconductor structure 300 may be scanned in fixed steps.
In an embodiment of the present invention, the step size may be in a range of 1.22-1.83 nm. Preferably, the step size may be 1.22 nm.
Fig. 4 is a schematic diagram of a first extension region and a second extension region of a method for measuring nitrogen content in a semiconductor structure in accordance with an embodiment of the present invention. Referring to FIG. 4, as the semiconductor structure 400 is scanned, an incident electron beam forms a first extension area 411 at the bottom of the charge trapping layer 401 in a first collection area 410 of the semiconductor structure 400, and a second extension area 421 at the bottom of the charge trapping layer 401 in a second collection area 420 adjacent to the first collection area 410. Wherein the first extension area 411 and the second extension area 421 do not overlap at least. In one example shown in fig. 4, the first expanded area 411 is connected to but does not overlap the second expanded area 421. It is understood that the first expansion area 411 and the second expansion area 421 can also be unconnected areas (not shown), but the embodiment is not limited thereto.
Fig. 5 is a scanning diagram of a method for measuring nitrogen content in a semiconductor structure according to an embodiment of the present invention, wherein the step size is 0.7 nm. Fig. 6 is a scanning diagram of a method for measuring nitrogen content in a semiconductor structure according to an embodiment of the present invention, wherein the step size is 1.22 nm.
Referring to fig. 4 to 6, an incident electron beam having a certain diameter (d) may have a certain degree of diffusion in the semiconductor structure 400, and the diffusion may cause the active area of the incident electron beam in the collecting region to be larger than the incident cross-sectional area of the incident electron beam itself.
In one example shown in fig. 5, the incident diameter of the incident electron beam is 0.3nm and the step size is 0.7 nm. The incident electron beam is diffused within the semiconductor structure 500 and the active areas of the incident electron beam overlap for adjacent collection areas, resulting in atoms within the (N + 1) th collection area having been acted upon by the incident electron beam of the nth collection area. Since the radiation damage caused by the incident electron beam to the silicon nitride in the semiconductor structure 500 is permanent, the overlapping of the action areas of the incident electron beam in adjacent collection areas affects the measurement result of the nitrogen content in the semiconductor structure 500.
In one example shown in fig. 6, the incident diameter of the incident electron beam is 0.3nm and the step size is 1.22 nm. The incident electron beam is spread within the semiconductor structure 600 without overlapping the active areas of the incident electron beam in adjacent collection areas. Atoms in the (N + 1) th collection region are not affected by the incident electron beam of the (N) th collection region. This step setting without overlapping the active areas of the incident electron beams of adjacent acquisition areas significantly reduces the influence of the incident electron beams on the measurement of the nitrogen content in the semiconductor structure 600.
FIG. 7A is a pre-scan imaging plot of a semiconductor structure with a step size of 0.7nm for a method of measuring nitrogen content in the semiconductor structure in accordance with one embodiment of the present invention. FIG. 7B is a graph of an image of a semiconductor structure after scanning with a step size of 0.7 nm.
Referring to fig. 7A and 7B, when the step size is 0.7nm, the tunneling layer 703 of the semiconductor structure 700 undergoes a significant structural change after the semiconductor structure 700 is scanned. During scanning, the incident electron beam causes severe radiation damage to the tunneling layer 703.
FIG. 8A is a pre-scan imaging plot of a semiconductor structure with a step size of 1.22nm for a method of measuring nitrogen content in a semiconductor structure in accordance with one embodiment of the present invention. FIG. 8B is a graph of an image of a semiconductor structure after scanning with a step size of 1.22 nm.
Referring to fig. 8A and 8B, when the step size is 1.22nm, no significant structural change occurs in the tunneling layer 803 of the semiconductor structure 800 after the semiconductor structure 800 is scanned. The incident electron beam causes little radiation damage to the tunneling layer 803 during scanning.
It should be noted that the semiconductor structures (semiconductor structure 300, semiconductor structure 400, semiconductor structure 500, semiconductor structure 600, semiconductor structure 700, and semiconductor structure 800) described in fig. 3-8B are all the semiconductor structure 200 provided in step 110 or are the same semiconductor structure as the semiconductor structure 200.
FIG. 9 is an electron energy loss map of nitrogen content of a semiconductor structure at a step size of 0.7nm and at a step size of 1.22nm for a method of measuring nitrogen content in a semiconductor structure in accordance with an embodiment of the present invention.
After scanning the semiconductor structure 700 and the semiconductor structure 800, the electron energy loss maps of nitrogen content at two step lengths shown in fig. 9 can be obtained by using the depth as the abscissa and the nitrogen content percentage as the ordinate, respectively.
And step 130, determining the nitrogen content in the charge trapping layer and the tunneling layer according to the nitrogen content electron energy loss map.
From the electron energy loss maps of nitrogen content for the scanned semiconductor structure 700 and the scanned semiconductor structure 800 shown in fig. 9, the nitrogen content in the charge trapping layer and the tunneling layer in the scanned semiconductor structure 700 and the semiconductor structure 800, respectively, can be determined.
In the nitrogen-content electron energy loss profile shown in FIG. 9, the tunneling layer (e.g., tunneling layer 703 and tunneling layer 803) and the charge trapping layer (e.g., charge trapping layer 702 and charge trapping layer 802)
Referring to FIG. 9, the nitrogen content of the tunneling layer 703 of the semiconductor structure 700 at a step size of 0.7nm is significantly less than the nitrogen content of the tunneling layer 803 of the semiconductor structure 800 at a step size of 1.22 nm.
FIG. 10 is a nitrogen content electron energy loss map of a semiconductor structure at different durations of a method of measuring nitrogen content in the semiconductor structure, in accordance with an embodiment of the present invention.
The semiconductor structure is scanned at different step sizes to obtain a nitrogen content electron energy loss map of the semiconductor structure. In the nitrogen content electron energy loss map shown in fig. 10, the abscissa is depth, and the ordinate is nitrogen content percentage.
Referring to fig. 10, as the step size increases from 0.5nm to 1.22nm, the nitrogen content of the tunneling layer (e.g., tunneling layer 203) of the semiconductor structure (e.g., semiconductor structure 200) increases. When the step size is increased from 1.22nm to 1.83nm, the nitrogen content of the tunneling layer of the semiconductor structure does not change significantly.
On the other hand, as the step size is increased from 0.5nm to 1.83nm, the profile and peak of the charge trapping layer (e.g., charge trapping layer 202) portion of the electron energy loss map of the nitrogen content of the semiconductor structure does not change significantly. However, when the step size is increased to 2.04nm, the nitrogen content electron energy loss map is distorted due to too low resolution.
In one embodiment of the present invention, the peak of the nitrogen content in the electron energy loss map of the nitrogen content can be read as the nitrogen content in the charge trapping layer and the tunneling layer. Illustratively, a step size of 1.22nm is set and a semiconductor structure (e.g., semiconductor structure 200) is scanned to obtain electron energy loss maps of nitrogen content for 30 different collection regions. The peak of the nitrogen content in the electron energy loss profile of the nitrogen content was read as the nitrogen content in the charge trapping layer and the tunneling layer. The Average (Average) and Standard Deviation (STD) of the nitrogen content in the tunneling layer (e.g., tunneling layer 203) and the charge-trapping layer (e.g., charge-trapping layer 202) of the semiconductor structure were calculated, respectively, and the statistical results are shown in table 1.
TABLE 1
Referring to table 1, the absolute value of the measurement accuracy (3 σ) of the nitrogen content in the tunneling layer and the charge trapping layer of the semiconductor structure can reach 3%.
In other embodiments of the present invention, the average value of the nitrogen content in the electron energy loss spectrum of the nitrogen content can be read as the nitrogen content in the charge trapping layer and the tunneling layer, but the embodiment is not limited thereto.
The method for measuring the nitrogen content in the semiconductor structure can effectively reduce the irradiation damage of the incident electron beam to the semiconductor structure on the premise of ensuring the Signal-to-Background Ratio (SBR), thereby improving the measurement precision of the nitrogen content. When the step size is set to a large value (e.g., 1.22nm), the effect of the incident electron beam on the semiconductor structure, especially the irradiation damage to silicon nitride in the semiconductor structure, can be significantly reduced.
It should be noted that the flowchart shown in fig. 1, for example, is used above to illustrate the operations performed by the method according to an embodiment of the present application. It will be appreciated that the preceding operations are not necessarily performed in the exact order in which they are performed. Rather, various steps may be processed in reverse order or simultaneously. Meanwhile, other operations are added to or removed from these processes.
The above embodiments of the present invention provide a method for measuring nitrogen content in a semiconductor structure, which can effectively improve the measurement accuracy of nitrogen content in a semiconductor structure.
Another aspect of the present invention provides an apparatus for measuring nitrogen content in a semiconductor structure, which can effectively improve the measurement accuracy of nitrogen content in the semiconductor structure.
The semiconductor structure in the device for measuring the nitrogen content in the semiconductor structure comprises a charge trapping layer and a tunneling layer formed on the charge trapping layer. The device for measuring the nitrogen content in the semiconductor structure comprises a transmission electron microscope and a platform.
Transmission electron microscopy was used to scan the semiconductor structure to obtain a nitrogen content electron energy loss map of the semiconductor structure. Wherein the incident electron beam forms a first extended region at the bottom of the charge trapping layer in a first acquisition region and a second extended region at the bottom of the charge trapping layer in a second acquisition region adjacent to the first acquisition region, the first extended region and the second extended region being at least non-overlapping.
In some examples of the invention, the transmission Electron microscope further comprises an Electron Energy Loss Spectroscopy (EELS). The electron energy loss spectrometer can utilize incident electron beams to generate inelastic scattering in a semiconductor structure, and the energy lost by electrons directly reflects information such as a scattering mechanism, chemical composition and thickness of the semiconductor structure, so that the element composition, chemical bonds, electronic structure and the like of a micro-region of the thin semiconductor structure are analyzed.
The platform is used to determine the nitrogen content in the charge trapping layer and the tunneling layer based on the nitrogen content electron energy loss map. In some examples of the invention, a platform includes a computer device and computer software running on the computer device.
Illustratively, a computer device may include a memory and a processor. The memory is used to store instructions that are executable by the processor. The processor is configured to execute instructions to enable determination of nitrogen content in the charge-trapping layer and the tunneling layer from the nitrogen content electron energy loss map.
In some embodiments, the computer device further comprises a communication port, an input/output device, and an internal communication bus. The communication port may be responsible for data communication between the computer device and external devices. The input/output devices may support input/output data flow between the computer device and other components. By way of example, the input/output device may include one or more of the following components: input devices such as a keyboard, mouse, camera, display, scanner, touch screen, handwriting input pad, and microphone, or any combination thereof. The input/output device may input various numerical data or various non-numerical data, such as graphics, video, audio, and the like, to the computer device. The internal communication bus may enable data communication between components in the computer device.
It is understood that the method for measuring the nitrogen content in the semiconductor structure of the present application can be implemented in the above-mentioned device for measuring the nitrogen content in the semiconductor structure, but the present invention is not limited thereto.
The method for measuring the nitrogen content in the semiconductor structure is not limited to be implemented by a measuring device for the nitrogen content in one semiconductor structure, but can be cooperatively implemented by a plurality of measuring devices for the nitrogen content in the semiconductor structures connected in series. The means for measuring the nitrogen content of the in-line semiconductor structure may be connected and communicated via a local area network or a wide area network.
Other implementation details of the apparatus for measuring nitrogen content in a semiconductor structure of the present embodiment can refer to the embodiments described in fig. 1 to 10, and will not be further described herein.
The above embodiments of the present invention provide a device for measuring nitrogen content in a semiconductor structure, which can effectively improve the measurement accuracy of nitrogen content in a semiconductor structure.
Having thus described the basic concept, it will be apparent to those skilled in the art that the foregoing disclosure is by way of example only, and is not intended to limit the present application. Various modifications, improvements and adaptations to the present application may occur to those skilled in the art, although not explicitly described herein. Such modifications, improvements and adaptations are proposed in the present application and thus fall within the spirit and scope of the exemplary embodiments of the present application.
Also, this application uses specific language to describe embodiments of the application. Reference throughout this specification to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the present application is included in at least one embodiment of the present application. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the present application may be combined as appropriate.
Computer program code required for the operation of various portions of the present application may be written in any one or more programming languages, including an object oriented programming language such as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C + +, C #, VB.NET, Python, and the like, a conventional programming language such as C, Visual Basic, Fortran 2003, Perl, COBOL 2002, PHP, ABAP, a dynamic programming language such as Python, Ruby, and Groovy, or other programming languages, and the like. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any network format, such as a Local Area Network (LAN) or a Wide Area Network (WAN), or the connection may be made to an external computer (for example, through the Internet), or in a cloud computing environment, or as a service, such as a software as a service (SaaS).
Additionally, the order in which elements and sequences of the processes described herein are processed, the use of alphanumeric characters, or the use of other designations, is not intended to limit the order of the processes and methods described herein, unless explicitly claimed. While various presently contemplated embodiments of the invention have been discussed in the foregoing disclosure by way of example, it is to be understood that such detail is solely for that purpose and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements that are within the spirit and scope of the embodiments herein. For example, although the system components described above may be implemented by hardware devices, they may also be implemented by software-only solutions, such as installing the described system on an existing server or mobile device.
Similarly, it should be noted that in the preceding description of embodiments of the application, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to require more features than are expressly recited in the claims. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.
Although the present invention has been described with reference to the present specific embodiments, it will be appreciated by those skilled in the art that the above embodiments are merely illustrative of the present invention, and various equivalent changes and substitutions may be made without departing from the spirit of the invention, and therefore, it is intended that all changes and modifications to the above embodiments within the spirit and scope of the present invention be covered by the appended claims.
Claims (10)
1. A method of measuring nitrogen content in a semiconductor structure, comprising:
providing a semiconductor structure comprising a charge trapping layer and a tunneling layer formed over the charge trapping layer;
scanning the semiconductor structure to obtain a nitrogen content electron energy loss map of the semiconductor structure; wherein the incident electron beam forms a first extended region at the bottom of the charge trapping layer in a first acquisition region and a second extended region at the bottom of the charge trapping layer in a second acquisition region adjacent to the first acquisition region, the first extended region and the second extended region having at least no overlap;
and determining the nitrogen content in the charge trapping layer and the tunneling layer according to the nitrogen content electron energy loss map.
2. The measurement method of claim 1, wherein all acquisition regions of the semiconductor structure are scanned in fixed steps.
3. The measurement method of claim 1, wherein the semiconductor structure is scanned row-by-row or column-by-column from the same end.
4. The measurement method of claim 1, wherein the semiconductor structure is scanned row-by-row or column-by-column in a zigzag pattern.
5. The measurement method according to claim 3 or 4, characterized in that the acquisition regions of the same row or column in the semiconductor structure are scanned in fixed steps.
6. The measurement method according to claim 3, wherein the acquisition area of the nth row or column is scanned with a first fixed step size, and the acquisition area of the (N + 1) th row or column is scanned with a second fixed step size, which is not smaller than the second fixed step size, wherein N is a positive integer.
7. The method of measurement according to claim 1, wherein a peak value of a nitrogen content in the nitrogen content electron energy loss map is read as the nitrogen content in the charge trapping layer and the tunneling layer.
8. The method of measurement according to claim 1, wherein an average value of nitrogen contents in the nitrogen content electron energy loss map is read as the nitrogen content in the charge trapping layer and the tunneling layer.
9. The measurement method according to any one of claims 2 or 6, wherein the step size is 1.22-1.83 nm.
10. A device for measuring nitrogen content in a semiconductor structure, the semiconductor structure including a charge trapping layer and a tunneling layer formed over the charge trapping layer, the device comprising:
a transmission electron microscope adapted to scan the semiconductor structure to obtain a nitrogen content electron energy loss map of the semiconductor structure; wherein the incident electron beam forms a first extended region at the bottom of the charge trapping layer in a first acquisition region and a second extended region at the bottom of the charge trapping layer in a second acquisition region adjacent to the first acquisition region, the first extended region and the second extended region having at least no overlap;
a platform adapted to determine nitrogen content in the charge trapping layer and the tunneling layer from the nitrogen content electron energy loss map.
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