Method, system, device and medium for monitoring side wall film thickness

Abstract

The present disclosure provides a method, system, device and medium for monitoring the thickness of a sidewall film layer, and relates to the field of semiconductor technology. The method includes forming a target film layer on the sidewall of an initial functional structure in a device area on a substrate surface, using an online measurement device to measure the initial functional structure and the target film layer respectively, obtaining an initial critical dimension and a target critical dimension to determine the measured thickness of the target film layer, determining the measurement deviation of the target film layer by the online measurement device according to the measured thickness and slice thickness of the target film layer, providing a substrate to be tested, wherein the device area of ​​the substrate to be tested includes multiple initial functional structures, establishing a statistical process control table, and combining the measurement deviation, monitoring the measured thickness of the target film layer formed on the sidewall of the initial functional structure of the substrate to be tested by an online measurement device, so as to realize online monitoring of the thickness of the sidewall film layer, accurately control the thickness of the target film layer, and improve the performance of semiconductor devices.

Description

Background Art

[0002] In the semiconductor circuit manufacturing process, thin film materials are deposited on the wafer substrate in sequence to meet actual needs. The thickness of the thin film material is a key factor affecting the performance of semiconductor devices. Commonly used film thickness detection methods include offline monitoring (offline monitor) and online monitoring (inline monitor).

[0003] In the related art, offline monitoring is performed on a control wafer (optical wafer), and the process parameters for preparing the control wafer are consistent with the process parameters used in the product. However, when using a control wafer for offline monitoring, the thickness of the thin film layer in the device structure is poor due to the difference between the control wafer and the actual device structure. Online monitoring is an indirect measurement, mainly measuring the thickness of the film layer in the direction perpendicular to the substrate. However, it is impossible to directly obtain the thickness of the thin film layer at the device structure position, nor is it possible to measure the thickness of the thin film layer in the sidewall direction.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0005] The present invention discloses a method, system, device and storage medium for monitoring the thickness of the sidewall film layer. The film thickness of each functional structure in the device area measured by the online measuring equipment is calibrated by the slice result, and a statistical process control table is established to realize the real-time monitoring of the sidewall film layer thickness. This overcomes the problem of low accuracy and inability to measure the film thickness in the sidewall direction of the existing thin film thickness monitoring method provided in the related art to a certain extent.

[0006] Other features and advantages of the present disclosure will become apparent from the following detailed description, or may be learned in part by the practice of the present disclosure.

[0007] According to one aspect of the present disclosure, a method for monitoring the thickness of a sidewall film layer is provided, comprising: providing a substrate, a device region is formed on the surface of the substrate, the device region includes a plurality of initial functional structures periodically arranged along a first direction; using an online measurement device to measure a preselected initial functional structure to obtain an initial critical dimension of the initial functional structure; forming a target film layer on the sidewall of the preselected initial functional structure to obtain a target functional structure; using an online measurement device to measure the target functional structure to obtain a target critical dimension of the target functional structure; obtaining a measured thickness of the target film layer according to the initial critical dimension and the target critical dimension; slicing the target functional structure to obtain a slice thickness of the target film layer, determining a measurement deviation of the target film layer by the online measurement device according to a difference between the measured thickness of the target film layer and the slice thickness, providing a substrate to be measured, the device region of the substrate to be measured including a plurality of the initial functional structures, establishing a statistical process control table, and combining the measurement deviation to monitor the measured thickness of the target film layer formed on the sidewall of the initial functional structure of the substrate to be measured by the online measurement device.

[0008] In one embodiment of the present disclosure, the initial critical dimension includes the width of a single initial functional structure in the first direction, and the target critical dimension includes the width of a single target functional structure in the first direction; or, the initial critical dimension includes the spacing between adjacent initial functional structures in the first direction, and the target critical dimension includes the spacing between adjacent target functional structures in the first direction.

[0009] In one embodiment of the present disclosure, the target film layer includes a plurality of sub-target film layers; the target critical dimension includes a plurality of sub-target critical dimensions, wherein one sub-target film layer corresponds to one sub-target critical dimension.

[0010] In one embodiment of the present disclosure, when an online measurement device is used to measure a preselected initial functional structure, the preselected initial functional structure is determined in the following manner: an image of a device area in which the initial functional structure meets preset requirements is selected as a field of view image; and according to a preset design period of the initial functional structure, an initial functional structure whose period meets a first preset value range is determined within the field of view image as the preselected initial functional structure.

[0011] In one embodiment of the present disclosure, the initial functional structure that meets the preset requirements includes at least one of the following: the line edge roughness of the initial functional structure satisfies less than 0.3nm; the line width roughness of the initial functional structure satisfies less than 0.3nm; the key dimension consistency of the initial functional structure satisfies less than 0.2.

[0012] In one embodiment of the present disclosure, determining, in the field of view image, an initial functional structure whose design period satisfies a first preset value range according to a preset design period of the initial functional structure, includes: using the online measurement device to measure the first initial functional structure and the second initial functional structure in the field of view image to obtain the period of the initial functional structure, wherein the period of the initial functional structure is a first distance between an edge of the first initial functional structure and an edge corresponding to the second initial functional structure, or a second distance between a center of the first initial functional structure and a center of the second initial functional structure, and the first initial functional structure and the second initial functional structure are two adjacent initial functional structures; if the first distance and the second distance are within the first preset value range, the first initial functional structure or the second initial functional structure is used as the pre-selected initial functional structure.

[0013] In one embodiment of the present disclosure, the method further includes: if the first distance and / or the second distance are not within the first preset value range, adjusting the measurement parameters of the online measurement device until the measured first distance and second distance are within the first preset value range.

[0014] In one embodiment of the present disclosure, the method further includes: if the measurement parameters of the online measurement device are adjusted and the measured first distance and / or second distance are not within the first preset value range, then screening field of view images that meet preset requirements in an adjacent device area.

[0015] In one embodiment of the present disclosure, the method of measuring a pre-selected initial functional structure using an online measuring device to obtain an initial critical dimension of the initial functional structure includes: measuring a plurality of measuring points of the pre-selected initial functional structure along a second direction using an online measuring device to obtain a plurality of process critical dimensions; and calculating an average value of the plurality of process critical dimensions to obtain the initial critical dimension of the initial functional structure.

[0016] In one embodiment of the present disclosure, before calculating the average value of the multiple process critical dimensions to obtain the initial critical dimension of the initial functional structure, the method further includes: determining whether there are multiple process critical dimensions that are not within a second preset value range; if so, redetermining the initial functional structure in the device area; if not, performing the operation of calculating the average value of the multiple process critical dimensions to obtain the initial critical dimension of the initial functional structure.

[0017] In one embodiment of the present disclosure, the slice thickness of the target film layer includes the total slice thickness of the target film layer and the actual slice thickness of the sub-target film layer, wherein the measurement deviation of the target film layer by the online measurement device is determined based on the difference between the measured thickness of the target film layer and the slice thickness, including: calculating the difference between the measured thickness of the target film layer and the total slice thickness; if the difference exceeds a preset deviation range, adjusting the measurement parameters of the online measurement device until the difference between the measured thickness of the retested target film layer and the total slice thickness is within the preset deviation range.

[0018] In one embodiment of the present disclosure, the method further includes: if the difference does not exceed a preset deviation range, determining the total measurement deviation of the online measurement equipment for the target film layer based on the difference; and determining the thickness measurement deviation of each sub-target film layer by the online measurement equipment in sequence according to a preset order.

[0019] According to another aspect of the present disclosure, a system for monitoring the thickness of a sidewall film layer is provided, comprising:

[0020] A film deposition device, used for forming a target film layer on the side wall of an initial functional structure provided on a substrate to obtain a target functional structure, wherein a device area is formed on the surface of the substrate, and the device area includes a plurality of initial functional structures periodically arranged along a first direction; forming a target film layer on the side wall of the initial functional structure provided on a substrate to be tested, wherein the device area of ​​the substrate to be tested includes a plurality of the initial functional structures periodically arranged along the first direction;

[0021] An online measuring device is used to measure the initial functional structure preselected on the substrate to obtain the initial critical size of the initial functional structure; measure the target functional structure on the substrate to obtain the target critical size of the target functional structure; and measure the slice of the target functional structure on the substrate to obtain the slice thickness of the target film layer;

[0022] A data processing device communicates with the online measurement device, and is used to obtain the measured thickness of the target film layer according to the initial critical dimension and the target critical dimension; determine the measurement deviation of the target film layer by the online measurement device according to the difference between the measured thickness of the target film layer and the slice thickness; and establish a statistical process control table to monitor the measured thickness of the target film layer formed on the side wall of the initial functional structure of the substrate to be measured through the online measurement device in combination with the measurement deviation.

[0023] In one embodiment of the present disclosure, the data processing device communicates with the film deposition device, wherein the data processing device is also used to send the measured thickness variation trend of the target film layer of the substrate to be measured to the film deposition device; the film deposition device is also used to adjust the process parameters according to the measured thickness variation trend so that the measured thickness of the target film layer meets the process requirements.

[0024] According to another aspect of the present disclosure, an electronic device is provided, comprising: a processor; and a memory for storing executable instructions of the processor; wherein the processor is configured to perform the above-mentioned method for monitoring the thickness of a sidewall film layer by executing the executable instructions.

[0025] According to another aspect of the present disclosure, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the method for monitoring the thickness of a sidewall film layer is implemented.

[0026] According to another aspect of the present disclosure, a computer program product is provided, including executable instructions, which are stored in a computer-readable storage medium. A processor of an electronic device reads the executable instructions from the computer-readable storage medium, and the processor executes the executable instructions, so that the electronic device executes the above-mentioned method for monitoring the thickness of the sidewall film layer.

[0027] The present disclosure provides a method, system, device and medium for monitoring the thickness of a sidewall film layer. An online measuring device (such as HVSEM) is used to directly measure the initial critical dimensions of an initial functional structure preselected in a device area, and to measure the target critical dimensions of a target functional structure, to obtain the thickness of a target film layer. The target film layer thickness is corrected based on the slice thickness to determine the thickness measurement deviation of the target film layer by the online measuring device. A target film layer is formed on the sidewall of the initial functional structure of a substrate to be measured, a statistical process control table is established, and in combination with the measurement deviation, the measured thickness of the target film layer formed on the sidewall of the initial functional structure of the substrate to be measured is monitored by the online measuring device to achieve online monitoring of the target film layer thickness, accurately control the film layer thickness, and improve the performance of semiconductor devices.

[0028] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0030] Figure 1 A schematic diagram showing a semiconductor device in the related art;

[0031] Figure 2 A flow chart showing a method for monitoring the thickness of a sidewall film layer provided by an embodiment of the present disclosure;

[0032] Figure 3 A schematic diagram showing the structure of a semiconductor device for preparing an initial functional structure provided by an embodiment of the present disclosure;

[0033] Figure 4 A schematic diagram showing the structure of a semiconductor device for preparing a target functional structure provided by an embodiment of the present disclosure;

[0034] Figure 5 Show Figure 4 Detailed view of semiconductor devices;

[0035] Figure 6 A flow chart showing another method for monitoring the thickness of a sidewall film layer provided by an embodiment of the present disclosure;

[0036] Figure 7 A flow chart showing another method for monitoring the thickness of a sidewall film layer provided by an embodiment of the present disclosure;

[0037] Figure 8 a to 8d show the bit line structure and NON film layer images measured by the online measurement equipment provided by the embodiment of the present disclosure;

[0038] Fig. 9 A schematic diagram showing an initial functional structure cycle of an embodiment of the present disclosure;

[0039] Fig.10 A flow chart showing another method for monitoring the thickness of a sidewall film layer provided by an embodiment of the present disclosure;

[0040] Fig.11 A flow chart of a sidewall film thickness calibration method provided by an embodiment of the present disclosure is shown;

[0041] Fig.12 A comparison diagram showing the sub-target critical size of a target functional structure measured by an online measurement device provided by an embodiment of the present disclosure and the sub-target critical size of the target functional structure obtained by slice measurement;

[0042] Fig.13A schematic diagram showing a system for monitoring the thickness of a sidewall film layer provided by an embodiment of the present disclosure;

[0043] Fig.14 A framework diagram of an electronic device provided by an embodiment of the present disclosure is shown;

[0044] Fig.15 A schematic diagram showing a computer program product provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0045] The preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0046] The terms "first" and "second" in this document are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly stated that it is a limitation.

[0047] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0048] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed.

[0049] Figure 1 FIG. 1 is a schematic diagram of a semiconductor device in the related art. Figure 1As shown, the semiconductor device in the related art includes a substrate 110, a plurality of device regions 120 are provided on the substrate 110, a cutting path is provided on the substrate 110 outside the device region 120, and a monitoring pad is provided at the cutting path. In the related art, the control of the thin film layer deposition process is achieved by measuring the thickness of the thin film layer at the monitoring pad. However, the monitoring method belongs to indirect measurement, and the thickness of the thin film layer at the monitoring pad is different from the device structure position in the device region 120, resulting in a large measurement error. Moreover, the monitoring method measures the thickness of the thin film layer in the vertical direction, and there is a difference between the thickness of the thin film layer in the direction parallel to the substrate (i.e., the sidewall direction) and the thickness of the thin film layer in the direction perpendicular to the substrate, resulting in the above method having poor effect on the thickness measurement of the thin film layer in the sidewall direction. Another method is to perform physical failure analysis (PFA) on semiconductor devices at the device structure location, that is, to perform fixed-point slicing and then perform a series of measurements on the cut surface. However, this method is destructive and will directly scrap the wafer, making subsequent process steps impossible. The cost is too high, and inaccurate slicing positions may require repeated slicing, which will also lead to higher measurement costs.

[0050] Therefore, how to accurately measure the thickness of the thin film layer in the side wall direction online has become one of the urgent problems to be solved.

[0051] In order to solve the above technical problems, the method for monitoring the thickness of the sidewall film layer provided in the embodiment of the present disclosure adopts an online measuring device (such as HVSEM) to directly measure the initial critical dimensions of the initial functional structure pre-selected in the device area, and measures the target critical dimensions of the target functional structure. According to the initial critical dimensions of the initial functional structure and the target critical dimensions of the target function, the thickness of the target film layer is determined, and the thickness of the target film layer is calibrated through the slicing results to determine the thickness measurement deviation of the target film layer by the online measuring device, and a statistical process control chart (SPC Chart) of the target film layer is established according to the thickness measurement deviation, thereby realizing online monitoring of the thickness of the sidewall film layer in the device area, accurately controlling the thickness of the target film layer, and improving the device accuracy.

[0052] It should be pointed out that the embodiments of the present invention and the technical features therein may be combined with each other without conflict.

[0053] The present exemplary implementation is described in detail below with reference to the accompanying drawings and embodiments.

[0054] Figure 2 A flow chart of a method for monitoring the thickness of a sidewall film layer provided by an embodiment of the present disclosure is shown. Figure 2 As shown, the method for monitoring the thickness of the sidewall film layer provided in this embodiment includes:

[0055] S202, providing a substrate, wherein a device region is formed on the surface of the substrate, and the device region includes a plurality of initial functional structures arranged in a periodic array along a first direction.

[0056] In one embodiment, the substrate may be a silicon-based substrate, etc., and a plurality of device regions are formed on the surface of the substrate, and a plurality of functional structures arranged in a periodic array along a first direction are formed in the device region. The first direction is parallel to the direction of the substrate surface, and the second direction is perpendicular to the direction of the substrate surface. In order to form a periodically arrayed functional structure on the substrate surface, a thin film layer may be prepared on the substrate by spin coating, deposition, and other techniques, and after etching, an initial functional structure arranged in a periodic array is formed according to the process design requirements.

[0057] In one embodiment, the initial functional structure may be a bit line structure arranged in a periodic array on a substrate; or it may be a structure requiring a composite film layer to be fabricated on the cylindrical sidewall, such as a deep hole structure, a groove structure, etc., which is not specifically limited in this application.

[0058] It should be noted that, depending on the different positions of the initial functional structures on the substrate, the period of the initial functional structures and the arrangement of the initial functional structures may be different, and may be determined according to actual needs.

[0059] S204, using online measuring equipment to measure the pre-selected initial functional structure to obtain the initial critical dimensions of the initial functional structure.

[0060] The online measuring equipment of this embodiment may include non-contact film thickness measuring equipment such as a high-voltage scanning electron microscope (HVSEM), a film thickness detector, and a laser film thickness measuring instrument. Preferably, the online measuring equipment may be an HVSEM.

[0061] In one embodiment, the initial functional structure serves as a reference for depositing a sidewall film layer. The accuracy and precision of the critical dimensions of the initial functional structure affect the monitoring accuracy of the sidewall film layer. Therefore, in the process of online monitoring of the thickness of the sidewall film layer, it is necessary to select an initial functional structure that meets the process requirements as the object of attention in the monitoring process. Before using an online measuring device for measurement, an initial functional structure that meets the process requirements is selected in the device area as a pre-selected initial functional structure, and the pre-selected initial functional structure is measured by the online measuring device to obtain an initial critical dimension of the initial functional structure.

[0062] The initial critical dimension may include a width of a single initial functional structure in the first direction, or the initial critical dimension may also include a distance between adjacent initial functional structures in the first direction.

[0063] The shapes of the initial functional structures are different, and the measurement methods and measurement positions of the key dimensions of the initial functional structures are also different. For example, for a bit line structure, its key dimension may be the width of a single bit line structure or the spacing between adjacent bit line structures in the first direction.

[0064] S206, forming a target film layer on the side wall of the pre-selected initial functional structure to obtain a target functional structure.

[0065] In one embodiment, after the initial critical dimensions of the initial functional structure are obtained, a target film layer is formed on the sidewall of the initial functional structure by thin film preparation processes such as spin coating, deposition, and etching.

[0066] It should be noted that the target film layer includes at least one sub-target film layer along the first direction. When the target film layer includes at least two film layers, the at least two film layers are sequentially formed on the sidewalls of the initial functional structure along the first direction (i.e., the direction parallel to the substrate surface).

[0067] In one embodiment, the target film layer may include a nitride-oxide-nitride composite film layer (Nitride-Oxide-Nitride, NON), or the target film layer may include a transformed structure of a NON composite film layer, for example, removing the oxide in the middle of the NON composite film layer to form an air gap to reduce the leakage of the semiconductor structure; or, doping nitrogen or oxygen elements in a certain thin film layer as needed to obtain a transformed structure of the NON composite film layer.

[0068] It should be noted that, in addition to the NON composite film layer or its transformed structure, the target film layer can also be obtained by adding or deleting thin film layers, replacing the material of the thin film layer, etc. according to actual needs, and this application does not make specific limitations.

[0069] By forming a target film layer on the side wall of a pre-selected initial functional structure to obtain a target functional structure, the measurement point positions of the target functional structure and the initial functional structure can be made consistent, thereby ensuring the accuracy of the measurement.

[0070] S208. Use online measuring equipment to measure the target functional structure to obtain a target critical dimension of the target functional structure.

[0071] In order to ensure the consistency and accuracy of the measurement process, the target film layer of the pre-selected initial functional structure side wall is selected as the measurement object.

[0072] It should be noted that the target critical dimension may include the width of a single target functional structure in the first direction; or the target critical dimension may include the spacing between adjacent target functional structures in the first direction. When the target film layer includes at least two sub-target film layers, the target critical dimension includes at least two sub-target critical dimensions, and one sub-target film layer corresponds to one sub-target critical dimension.

[0073] S210, obtaining a measured thickness of a target film layer according to the initial critical dimension and the target critical dimension.

[0074] In one embodiment, the thickness of the target film layer is obtained by: calculating the film thickness difference between the target critical dimension and the initial critical dimension; and calculating the measured thickness of the target film layer according to the film thickness difference.

[0075] Exemplarily, for the NON film layer, the thickness of the NON film layer is 1 / 2 of the film thickness difference between the target critical dimension of the NON film layer and the initial critical dimension of the bit line structure.

[0076] Exemplarily, the NON film layer includes three sub-target film layers, and the thickness of each sub-target film layer can be determined by using the critical dimensions of adjacent sub-target film layers or the critical dimensions of the sub-target film layers and the bit line structure.

[0077] S212, slicing the target functional structure to obtain the slice thickness of the target film layer, and determining the measurement deviation of the target film layer by the online measurement device according to the difference between the measured thickness of the target film layer and the slice thickness.

[0078] It should be noted that fixed-point slicing is a commonly used analysis method for physical failure analysis (PFA). Usually, the wafer is first cut, and then a series of measurements and analyses are performed on the cut surface. The size of the structure can be observed intuitively. The default accuracy is high, and the PFA slice thickness of the device structure can be used as real data.

[0079] In order to characterize the target film layer on the side wall of the initial functional structure, the slice includes at least a pre-selected initial functional structure and the target film layer on the side wall of the initial functional structure. The target critical size (or slice thickness) of the target film layer obtained by the slice thickness can be used as the true value of the thickness of the target functional structure measured by HVSEM; the total slice thickness of the target film layer obtained by fixed-point slicing is used as the true thickness of the target film layer measured by HVSEM, and the sub-target film layer thickness of the sub-target film layer obtained by fixed-point slicing is used as the true film layer thickness of the sub-target film layer measured by HVSEM.

[0080] It should be noted that, in addition to using the fixed-point slice thickness as the actual thickness of the calibration target film layer, optical critical dimension (OCD) and other means may also be used for auxiliary verification, which is not specifically limited in this application.

[0081] In some embodiments, the measurement deviation of the target film layer by the online measurement equipment can be characterized by the difference between the thickness of the target film layer measured by the online measurement equipment and the slice thickness of the target film layer, or it can be characterized by the ratio between the thickness of the target film layer measured by the online measurement equipment and the slice thickness of the target film layer.

[0082] S214, providing a substrate to be tested, wherein the device region of the substrate to be tested includes a plurality of initial functional structures, establishing a statistical process control table, and combining the measurement deviation to monitor the measured thickness of a target film layer formed on the side wall of the initial functional structure of the substrate to be tested by an online measuring device.

[0083] Based on the design requirements of the target film layer, a statistical process control table is established to perform online monitoring of the thickness of the target film layer formed on the side wall of the initial functional structure of the substrate to be tested in combination with the measurement deviation and the statistical process control table. When the monitored thickness of the target film layer is consistent with the target film layer thickness range set in the statistical process control table, it indicates that the target film layer prepared using the current process conditions meets the process design requirements, and the actual thickness of the target functional structure can be obtained based on the measurement deviation; when the monitored thickness of the target film layer cannot meet the target film layer thickness range set in the statistical process control table, it indicates that the target film layer prepared using the current process conditions cannot meet the process design requirements, and the process parameters need to be adjusted.

[0084] The method for monitoring the thickness of the sidewall film layer provided in the embodiment of the present disclosure directly measures the initial critical dimensions of the initial functional structure pre-selected in the device area and measures the target critical dimensions of the target functional structure by using an online measuring device (such as HVSEM) to obtain the measured thickness of the target film layer, obtains the actual thickness of the target film layer based on the slicing result, determines the measurement deviation of the target film layer by the online measuring device according to the slicing thickness and the measured thickness, establishes a statistical process control table, and based on the film thickness measurement deviation, performs online monitoring on the measured thickness of the target film layer formed on the sidewall of the initial functional structure of the substrate to be measured by the online measuring device, so as to accurately control the thickness of the target film layer and improve the performance of the semiconductor device.

[0085] Figure 3 to Figure 5 The schematic diagram of the structure of the semiconductor device provided by the embodiment of the present disclosure is shown. The following is an example of forming a NON composite film layer on the side wall of the bit line structure and online monitoring the thickness of each thin film layer in the NON composite film layer.

[0086] like Figure 3As shown, a plurality of bit line structures 210 are formed in a device region on a substrate 110 , and the plurality of bit line structures 210 are arranged in a periodic array in a first direction.

[0087] A bit line structure is selected, and the selected bit line structure is measured by an online monitoring device to obtain an initial critical dimension d0 of the bit line structure.

[0088] like Figure 4 As shown, a NON composite film layer 210 is formed on the sidewall of the bit line structure 210 by a thin film deposition process.

[0089] like Figure 5 As shown, the NON composite film layer 210 includes a first nitride film layer 2201 formed on the side wall of the bit line structure 210, an oxide film layer 2202 formed on the side wall of the first nitride film layer 2201, and a second nitride film layer 2203 formed on the side wall of the oxide film layer 2202, wherein the initial critical dimension of the bit line structure 210 is d0, the sub-target critical dimension of the first nitride film layer 2201 is d1, the sub-target critical dimension of the oxide film layer 2202 is d2, and the sub-target critical dimension of the second nitride film layer 2203 is d3.

[0090] The thickness Δd of the NON composite film layer is expressed as:

[0091] Δd=(d3-d0) / 2 (Formula 1)

[0092] The thickness Δd1 of the first nitride film layer 2201 is expressed as:

[0093] Δd1=(d1-d0) / 2 (Formula 2)

[0094] The thickness Δd2 of the oxide film layer 2202 is expressed as:

[0095] Δd2=(d2-d1) / 2 (Formula 3)

[0096] The thickness Δd3 of the second nitride film layer 2203 is expressed as:

[0097] Δd3=(d3-d2) / 2 (Formula 4)

[0098] Figure 6 FIG. 2 is a flow chart showing another method for monitoring the thickness of a sidewall film layer provided by an embodiment of the present disclosure. Figure 6 As shown, in one embodiment, the pre-selected initial functional structure is determined by:

[0099] S602, selecting an image of a device area whose initial functional structure meets preset requirements as a field of view image;

[0100] S604 , according to the preset design period of the initial functional structure, determine in the field of view image an initial functional structure whose period meets a first preset value range as the pre-selected initial functional structure.

[0101] In one embodiment, the initial functional structure that meets the preset requirements includes at least one of the following: the line edge roughness of the initial functional structure is less than 0.3nm; the line width roughness of the initial functional structure is less than 0.3nm; the key dimension consistency of the initial functional structure is less than 0.2.

[0102] Exemplarily, using the high-voltage mode of the HVSEM machine, periodic images of the initial functional structure are taken in the device area. Before measuring the initial critical dimensions of the initial functional structure, a field of view image whose line edge roughness, line width roughness and critical dimension consistency meet the preset requirements is selected as a calibration golden image. It should be noted that the preset requirement of meeting the process design specification is an actual requirement.

[0103] In some embodiments, two initial functional structures can be randomly selected directly in the image of the device area to determine whether the initial functional structures meet the preset requirements, and the initial functional structure that meets the preset requirements can be selected, and the period of the initial functional structure can be measured, and then the initial functional structure whose period meets the first preset value range can be selected as the pre-selected initial functional structure. It should be noted that the present disclosure does not specifically limit the selection method of the initial functional structure.

[0104] The disclosed embodiment selects an image with ideal line edge roughness, line width roughness, and key dimension consistency as a calibration golden image, that is, the size of the initial functional structure is within the specification line required by the process design specification, thereby providing a guarantee for the subsequent measurement of the thickness of the target film layer and improving the accuracy of film thickness monitoring.

[0105] Figure 7 A flow chart showing another method for monitoring the thickness of a sidewall film layer provided by an embodiment of the present disclosure is shown. Figure 6 Based on the embodiment, step S604 is further refined into S702-S712, and the specific selection method of the initial functional structure is disclosed. Figure 7 As shown, a method for monitoring the thickness of a sidewall film layer provided by an embodiment of the present disclosure specifically includes:

[0106] S702, measuring the first initial functional structure and the second initial functional structure in the field of view image by using an online measuring device to obtain a period of the initial functional structure, wherein the period of the initial functional structure is a first distance between an edge of the first initial functional structure and an edge corresponding to the second initial functional structure, or a second distance between a center of the first initial functional structure and a center of the second initial functional structure, and the first initial functional structure and the second initial functional structure are two adjacent initial functional structures;

[0107] S704, determining whether the first distance and the second distance are within a first preset value range, if satisfied, executing S706, if not satisfied, executing S708;

[0108] S706: Use the first initial functional structure or the second initial functional structure as a pre-selected initial functional structure.

[0109] Optionally, the method further includes:

[0110] S708, adjusting the measurement parameters of the online measurement device, using the online measurement device to measure the first initial functional structure and the second initial functional structure, and obtaining the period of the initial functional structure;

[0111] S710, determining whether the first distance and the second distance are within a first preset value range, if satisfied, executing S706; if not satisfied, executing S712;

[0112] S712, screening field of view images that meet preset requirements in adjacent device areas.

[0113] 8a to 8d show the bit line structure and NON film layer images measured by the online measurement equipment provided by the embodiment of the present disclosure. Figure 8 As shown in a, the image includes 7 bit line structures in total, among which the first, third, fifth and seventh bit line structures are periodic bit line structures located in the same row; the second, fourth and sixth bit line structures are periodic bit line structures located in another row. Taking the first bit line structure as the first initial functional structure as an example, the period of the initial functional structure is described in detail.

[0114] Fig. 9 A schematic diagram showing the initial functional structure cycle of an embodiment of the present disclosure is shown. Fig. 9 As shown, for the first bit line structure, Fig. 9 The third bit line structure in the embodiment is an adjacent bit line structure to the first bit line structure, that is, the third bit line structure serves as a second initial functional structure.

[0115] The period T of the initial functional structure is a first distance T1 from the left edge (or right edge) of the first bit line structure to the left edge (or right edge) of the third bit line structure; or the period T of the initial functional structure is a second distance T2 from the center of the first bit line structure to the center of the third bit line structure.

[0116] In addition to using adjacent initial functional structures to obtain the period of the initial functional structure, the distance from the edge to the corresponding edge and the center to center of any two initial functional structures in the same row can also be measured. Based on the above distances and the number of periods, the period of the initial functional structure can be obtained.

[0117] For example, Fig. 9 As shown, the period number of the first bit line structure and the fifth bit line structure is 2. The edge-to-edge distance and the center-to-center distance of the first bit line structure and the fifth bit line structure are measured, and the ratio between the above distance and the period number is calculated to obtain the period of the bit line structure. For the first bit line structure and the seventh bit line structure, the period number is 3. The same calculation method is used to obtain the period of the initial functional structure, which will not be repeated here.

[0118] It should be noted that the first preset value range can be set according to actual process requirements. For example, the first preset value range is 0.5nm to 1nm, wherein the smaller the endpoint value of the first preset value range, the smaller the interval length of the first preset value range, indicating that the process requirements are more stringent, and the larger the endpoint value of the first preset value range, the larger the interval length of the first preset value range, indicating that the process requirements are more relaxed. This application does not make specific restrictions on the specific values ​​of the first preset value range.

[0119] In some embodiments, the measurement parameters of the online measurement equipment include but are not limited to the measurement magnification, the measurement voltage, or the incident angle and intensity of the measurement light; the measurement is performed by adjusting the measurement parameters of the HVSEM machine, such as the magnification, so that the periods T1 and T2 of the measured functional structure are consistent with the process design requirements, thereby determining the position of the measurement point. During the measurement process, an image with a larger measurement magnification is selected as a reference figure, such as 5 times to 10 times.

[0120] It should be noted that the center of the initial functional structure may be a center plane, a center line or a center point, which may be selected based on the convenience of measurement.

[0121] The disclosed embodiment selects an image of an initial functional structure that meets preset requirements in a device area as a calibration golden image, and determines a pre-selected initial functional structure according to a preset design period of the initial functional structure. For the initial functional structure, an image with a larger measurement magnification is selected as a reference figure, thereby reducing the influence of the reference figure on the positioning of the measurement point, ensuring the consistency of the measurement position during the measurement process, and improving the measurement repeatability and accuracy.

[0122] In one embodiment, the method for monitoring the thickness of the sidewall film layer provided by the embodiment of the present disclosure further includes:

[0123] If the first distance and / or the second distance are not within the first preset value range, the measurement parameters of the online measurement device are adjusted until the measured first distance and second distance are within the first preset value range.

[0124] In some embodiments, Figure 7 As shown, the method also includes:

[0125] S708: If the first distance and the second distance are not within the first preset value range, adjusting the measurement parameters of the online measurement device, and using the online measurement device to measure the period of the first initial functional structure and the second initial functional structure;

[0126] S710, determining whether the first distance and the second distance are within a first preset value range, if satisfied, executing S706; if not satisfied, executing S712;

[0127] S712, screening the field of view images that meet the preset requirements in the adjacent device area, reselecting the first initial functional structure and the second initial functional structure in the field of view image, and re-determining the target functional structure, until the initial functional structure that meets the first preset value range is screened out.

[0128] It should be noted that if at least one of the first distance or the second distance is not within the first preset value range, it indicates that the selected first initial functional structure or the second initial functional structure does not meet the process design requirements. The measurement parameters of the online measurement equipment are adjusted to determine whether the measurement parameters of the online measurement equipment are suitable when measuring the initial functional structure. If the measurement parameters are adjusted so that the measured thickness meets the process requirements, the initial functional structure is used as the pre-selected initial functional structure. If after adjusting the measurement parameters, the first distance and the second distance are still not within the first preset value range, the field of view images that meet the preset requirements are re-screened in the adjacent device area, and the first initial functional structure and the second initial functional structure are re-selected to improve the measurement efficiency.

[0129] In one embodiment of the present disclosure, the method further includes:

[0130] If the first initial functional structure and the second initial functional structure are selected consecutively for a preset number of times in the field of view image, and the measured first distance and / or second distance is not within the first preset value range, the field of view image that meets the preset requirements is rescreened in the adjacent device area.

[0131] In some embodiments, in the field of view image, if the first initial functional structure and the second initial functional structure selected for multiple times are not within the first preset value range, it indicates that the initial functional structures selected in the field of view image cannot meet the process design requirements. Even if there are unselected initial functional structures in the field of view image, it also indicates that the remaining initial functional structures in the field of view image cannot meet the process design requirements, and the field of view image is reselected. The preset number of times can be determined according to the actual situation, for example, 5 times can be used, and this application does not make specific restrictions.

[0132] The present disclosure ensures the reliability of the target functional structure by monitoring the number of consecutive selections of the first initial functional structure and the second initial functional structure, thereby providing strong support for subsequent deposition of the target film layer and measurement of the thickness of the target film layer.

[0133] Fig.10 A flow chart showing another method for monitoring the thickness of a sidewall film layer provided by an embodiment of the present disclosure is shown. Fig.10 As shown, step S204 uses an online measuring device to measure the pre-selected initial functional structure to obtain the initial critical dimensions of the initial functional structure, including: S1002, using an online measuring device to measure multiple measuring points of the pre-selected initial functional structure along the second direction to obtain multiple process critical dimensions; S1004, calculating the average value of the multiple process critical dimensions to obtain the initial critical dimensions of the pre-selected initial functional structure.

[0134] It should be noted that when measuring the initial functional structure, multiple measurement points are selected at different positions of the pre-selected initial functional structure along the second direction. For example, multiple measurement points are selected for measurement along the initial functional structure perpendicular to the periodic arrangement direction (perpendicular to the substrate surface direction, or the height direction of the initial functional structure), and each measurement point is measured at least twice to improve the measurement accuracy of the initial critical dimension.

[0135] In one embodiment of the present disclosure, before calculating the average value of multiple process critical dimensions to obtain the initial critical dimension of a pre-selected initial functional structure, the method also includes: determining whether there are multiple process critical dimensions that are not within a second preset value range; if so, redetermining the initial functional structure in the device area; if not, executing the operation of calculating the average value of multiple process critical dimensions to obtain the initial critical dimension of the pre-selected functional structure.

[0136] It should be noted that for images of initial functional structures that are blurred, of low precision, and of low grayscale contrast, during repeatability testing, large differences in the multiple process measurement values ​​obtained may occur. The above situations affect the accuracy of the target film thickness measurement, and the above initial functional structures need to be eliminated.

[0137] The second preset value range is determined according to actual needs and is not specifically limited in this application.

[0138] The disclosed embodiment effectively avoids using an initial functional structure that is unclear, has low precision, and has low grayscale contrast as a pre-selected initial functional structure by judging whether the critical dimension of the process is within a second preset value range, thereby improving the measurement accuracy.

[0139] Fig.11 A flow chart of another method for monitoring the thickness of a sidewall film layer provided by an embodiment of the present disclosure is shown. In one embodiment, the slice thickness of the target film layer includes the total slice thickness of the target film layer and the actual slice thickness of the sub-target film layer, and the measurement deviation of the target film layer by the online measuring device is determined according to the difference between the measured thickness of the target film layer and the slice thickness, including:

[0140] S1102, calculating the difference between the measured thickness of the target film layer and the total thickness of the slice;

[0141] S1104, determine whether the difference exceeds a preset deviation range, if so, execute S1106;

[0142] S1106, adjusting the measurement parameters of the online measurement equipment, retesting the target functional structure, obtaining a new measured thickness, and returning to S1102 until the difference between the thickness of the retested target film layer and the total thickness of the slices of the target film layer is within a preset deviation range.

[0143] In some embodiments, the selected sliced ​​samples are obtained using the same process parameters as those used to prepare the initial functional structure and the target functional structure. The sliced ​​samples can be samples from different device areas on the same substrate, or samples prepared using the same process parameters on a measurement substrate. The sliced ​​samples can also be samples used for measurement by online measurement equipment, without specific limitation.

[0144] When the difference between the slice thickness of the target film layer obtained by slicing and the thickness of the target film layer obtained by HVSEM measurement is within the preset deviation range, the difference between the two is used as the measurement deviation of the target film layer by the online measurement equipment, and the target film layer prepared by the current process parameters meets the process requirements; when the difference between the slice thickness of the target film layer obtained by slicing and the thickness of the target film layer measured by HVSEM is not within the preset deviation range, it is necessary to adjust the measurement parameters of the HVSEM machine until the difference between the measurement results obtained by the two measurement methods is within the preset deviation range.

[0145] In one embodiment, when the difference exceeds a preset deviation range, the total thickness of the target film layer needs to be calibrated. When the difference is a positive value, a negative compensation value is assigned to the total thickness of the target film layer; when the difference is a positive value, a positive compensation value is assigned to the total thickness of the target film layer.

[0146] The size of the compensation value can be determined by the difference between the difference and the endpoint value of the preset deviation range or the middle value of the preset deviation range. For example, the difference between the total thickness of the target film layer and the total thickness of the slice is 1.5nm, and the preset deviation range is [-1nm, 1nm]. This indicates that the total thickness of the target film layer is larger than the actual thickness and needs to be calibrated to reduce the total thickness of the target film layer. The compensation value is a negative value, such as -1nm to -1.5nm.

[0147] It should be noted that the calibration method of each thin film layer is consistent with the calibration method of the target film total thickness, that is, adjusting the measurement parameters of the HVSEM machine so that the difference between the HVSEM measurement result and the slicing result is within the preset deviation range, which will not be repeated here.

[0148] The disclosed embodiment can determine the starting position and the end position of the target film layer by preferentially calibrating the total thickness of the target film layer, and then determine the thickness of each sub-target film layer in the target film layer, and successively establish a statistical process control (SPC) chart to continuously monitor the online process, accurately control the thickness of each sub-target film layer, and improve device performance.

[0149] Fig.11 FIG. 2 is a flow chart showing another method for monitoring the thickness of a sidewall film layer provided by an embodiment of the present disclosure. Fig.11 As shown, in another embodiment, the method further includes:

[0150] S1108, if the difference does not exceed the preset deviation range, determining the total measurement deviation of the online measurement device for the target film layer according to the difference;

[0151] S1110, determining the thickness measurement deviation of each sub-target film layer by the online measurement equipment in sequence according to a preset order.

[0152] In one embodiment, the difference between the total thickness of the target film layer and the total thickness of the slice is calculated, and based on the relationship between the difference and the preset deviation range, it can be determined whether the total thickness of the target film layer measured by HVSEM is consistent with the fixed-point slice result.

[0153] Exemplarily, the preset deviation range may be set to [-1 nm, 1 nm]. It should be noted that the preset deviation range may be determined according to actual needs, and this application does not make any specific limitation.

[0154] In one embodiment, the thickness of each sub-target film layer can be calibrated in sequence according to a preset order. The preset order can be calibrated from the inside to the outside, or from the outside to the inside. This application does not make any specific limitations.

[0155] In the present disclosure, when the total thickness of the target film layer is consistent with the thickness of the fixed-point slice, the thickness of the sub-target film layer is calibrated, thereby accurately defining the starting position and the ending position of the target film layer, thereby improving the accuracy of film layer monitoring.

[0156] Fig.12 A comparison diagram of the key dimensions measured online and obtained by the fixed-point slicing results provided by the embodiment of the present disclosure is shown. Fig.12 In the figure, the horizontal axis is the thickness of different sub-target film layers measured by the online test equipment, and the vertical axis represents the slice thickness range of different sub-target film layers. It can be found from the figure that after fitting, the thickness of different sub-target film layers measured by the online measurement equipment is linearly related to the slice thickness, and the slope is close to 1. Fig.12 As shown, the method for monitoring the thickness of the sidewall film layer provided by the present disclosure allows the measurement results obtained by the online measurement equipment to be consistent with those obtained by the slicing results.

[0157] Based on the same inventive concept, the present disclosure also provides a system for monitoring the thickness of the sidewall film layer, as described in the following embodiments. Since the principle of solving the problem in the system embodiment is similar to that in the above method embodiment, the implementation of the system embodiment can refer to the implementation of the above method embodiment, and the repeated parts will not be repeated.

[0158] Fig.13 FIG. 2 is a schematic diagram showing a system for monitoring the thickness of a sidewall film layer provided by an embodiment of the present disclosure. Fig.13 As shown, the system for monitoring the thickness of the sidewall film layer of this embodiment includes a film deposition device 1301, an online measurement device 1302 and a data processing device 1303, wherein:

[0159] The film deposition device 1301 is used to form a target film layer on the side wall of the initial functional structure of the substrate to obtain the target functional structure, wherein a device area is formed on the surface of the substrate, and the device area includes a plurality of initial functional structures periodically arranged along a first direction; the target film layer is formed on the side wall of the initial functional structure on the substrate to be tested, and the device area of ​​the substrate to be tested includes a plurality of initial functional structures periodically arranged along the first direction;

[0160] The online measuring device 1302 is used to measure the initial functional structure pre-selected on the substrate to obtain the initial critical dimension of the initial functional structure; measure the target functional structure on the substrate to obtain the target critical dimension of the target functional structure; measure the slice of the target functional structure on the substrate to obtain the slice thickness of the target film layer;

[0161] The data processing device 1303 communicates with the online measurement device to obtain the thickness of the target film layer based on the initial critical dimension and the target critical dimension; determine the measurement deviation of the target film layer by the online measurement device based on the difference between the measured thickness of the target film layer and the slice thickness; establish a statistical process control table to monitor the measured thickness of the target film layer formed on the side wall of the initial functional structure of the substrate to be measured through the online measurement device in combination with the measurement deviation.

[0162] In one embodiment, the data processing device 1303 communicates with the film deposition device 1301, wherein the data processing device 1303 is also used to send the measured thickness variation trend of the target film layer of the substrate to be tested to the film deposition device 1301; the film deposition device 1301 is also used to adjust the process parameters according to the measured thickness variation trend so that the measured thickness of the target film layer meets the process requirements.

[0163] By establishing a communication connection between the data processing device and the film deposition device, a feedback mechanism is used to adjust the process parameters of the film deposition device to adjust the thickness of the target film layer deposited subsequently. For example, an R2R adjustment system can be used. Specifically, during the deposition of the target film layer, if the change trend of the measured thickness of the target film layer is shown as the measured thickness is close to the maximum or minimum value of the SPC control range within a period of time, or the measured thickness of the target film layer shows a trend of continuous increase or continuous decrease within a period of time, the data processing device will feed back the corresponding change trend to the film deposition device to automatically or provide technicians with the ability to adjust the thickness of the film deposition device according to the change trend of the measured thickness.

[0164] In some embodiments, for example, when the measured thickness of the target film layer is not within the SPC control range, the data processing equipment sends a control instruction to the film deposition equipment, which can suspend the continued feeding of the film deposition equipment and issue an alarm message to remind relevant personnel to check and deal with the problem.

[0165] In one embodiment, the initial critical dimension comprises a width of a single initial functional structure in a first direction, and the target critical dimension comprises a width of a single target functional structure in the first direction;

[0166] Alternatively, the initial critical dimension includes the spacing between adjacent initial functional structures in the first direction, and the target critical dimension includes the spacing between adjacent target functional structures in the first direction.

[0167] It should be noted that the target film layer includes multiple sub-target film layers; the target critical dimension includes multiple sub-target critical dimensions, wherein one sub-target film layer corresponds to one sub-target critical dimension.

[0168] In one embodiment, the online measurement device 1302 is used to measure a pre-selected initial functional structure, wherein the pre-selected initial functional structure is determined in the following manner: an image of a device area in which the initial functional structure meets preset requirements is selected as a field of view image; and according to a preset design period of the initial functional structure, an initial functional structure whose period meets a first preset value range is determined in the field of view image as the pre-selected initial functional structure.

[0169] It should be noted that the initial functional structure that meets the preset requirements includes at least one of the following: the line edge roughness of the initial functional structure is less than 0.3nm; the line width roughness of the initial functional structure is less than 0.3nm; the key dimension consistency of the initial functional structure is less than 0.2.

[0170] In one embodiment, the online measuring device 1302 is used to measure the first initial functional structure and the second initial functional structure in the field of view image to obtain the period of the initial functional structure, wherein the period of the initial functional structure is a first distance between an edge of the first initial functional structure and an edge corresponding to the second initial functional structure, or a second distance between a center of the first initial functional structure and a center of the second initial functional structure, and the first initial functional structure and the second initial functional structure are two adjacent initial functional structures; if the first distance and the second distance are within a first preset value range, the first initial functional structure or the second initial functional structure is used as the pre-selected initial functional structure.

[0171] In some embodiments, the online measuring device 1302 is further used to adjust the measurement parameters of the online measuring device if the first distance and / or the second distance are not within the first preset value range until the measured first distance and second distance are within the first preset value range.

[0172] In some embodiments, the online measuring device 1302 is also used to adjust the measurement parameters of the online measuring device. If the measured first distance and / or the second distance is not within the first preset value range, a field of view image that meets the preset requirements is screened in an adjacent device area.

[0173] In some embodiments, the online measuring device 1302 is further used to measure a plurality of measuring points of the pre-selected initial functional structure along the second direction to obtain a plurality of process critical dimensions; the data processing device 1303 is further used to calculate an average value of the plurality of process critical dimensions to obtain an initial critical dimension of the pre-selected initial functional structure;

[0174] In one embodiment, the data processing device 1303 is also used to determine whether there are multiple process critical dimensions that are not within the second preset value range; if so, redetermine the initial functional structure in the device area; if not, perform the operation of calculating the average value of multiple process critical dimensions to obtain the initial critical dimension of the pre-selected initial functional structure.

[0175] In one embodiment, the slice thickness of the target film layer includes the total slice thickness of the target film layer and the actual slice thickness of the sub-target film layer, wherein the data processing device 1303 is also used to calculate the difference between the measured thickness of the target film layer and the total slice thickness; if the difference exceeds a preset deviation range, the measurement parameters of the online measurement device are adjusted until the difference between the measured thickness of the re-measured target film layer and the total slice thickness is within the preset deviation range.

[0176] In one embodiment, the data processing device 1303 is also used to determine the total measurement deviation of the online measurement device for the target film layer based on the difference if the difference does not exceed the preset deviation range; and determine the thickness measurement deviation of each sub-target film layer by the online measurement device in sequence according to a preset order.

[0177] A system for monitoring the thickness of a sidewall film layer provided by an embodiment of the present disclosure uses an online measuring device (such as HVSEM) to directly measure the initial critical dimensions of a pre-selected initial functional structure in a device area, and measures the target critical dimensions of a target functional structure, to obtain the measured thickness of the target film layer, and based on the difference between the slice thickness and the measured thickness, to determine the thickness measurement deviation of the target film layer by the online measuring device, to establish a statistical process control table, and to perform online monitoring of the measured thickness of the target film layer formed on the sidewall of the initial functional structure of the substrate to be measured through the online measuring device in combination with the measurement deviation, to accurately control the thickness of each sub-target film layer, and to improve the performance of the semiconductor device.

[0178] It will be appreciated by those skilled in the art that various aspects of the present invention may be implemented as a system, method or program product. Therefore, various aspects of the present invention may be specifically implemented in the following forms, namely: a complete hardware implementation, a complete software implementation (including firmware, microcode, etc.), or a combination of hardware and software, which may be collectively referred to herein as a "circuit", "module" or "system".

[0179] Refer to the following Fig.14 14 to 15. The electronic device 1400 according to this embodiment of the present invention is described. Fig.14 The electronic device 1400 shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present invention.

[0180] like Fig.14As shown, the electronic device 1400 is in the form of a general computing device. The components of the electronic device 1400 may include but are not limited to: at least one processing unit 1410, at least one storage unit 1420, and a bus 1430 connecting different system components (including the storage unit 1420 and the processing unit 1410).

[0181] The storage unit stores program codes, which can be executed by the processing unit 1410, so that the processing unit 1410 performs the steps according to various exemplary embodiments of the present invention described in the above “Exemplary Method” section of this specification. For example, the processing unit 1410 can perform the following steps: Figure 2 As shown in the method, a substrate is provided, a device area is formed on the surface of the substrate, and the device area includes a plurality of initial functional structures periodically arranged along a first direction; an online measuring device is used to measure a pre-selected initial functional structure to obtain an initial critical dimension of the initial functional structure; a target film layer is formed on the side wall of the pre-selected initial functional structure to obtain a target functional structure; an online measuring device is used to measure the target functional structure to obtain a target critical dimension of the target functional structure; a measured thickness of the target film layer is obtained based on the initial critical dimension and the target critical dimension; the target functional structure is sliced ​​to obtain a slice thickness of the target film layer, and a measurement deviation of the target film layer by the online measuring device is determined based on the difference between the measured thickness of the target film layer and the slice thickness; a substrate to be tested is provided, the device area of ​​the substrate to be tested includes a plurality of initial functional structures, and a statistical process control table is established to monitor the measured thickness of the target film layer formed on the side wall of the initial functional structure of the substrate to be tested by the online measuring device in combination with the measurement deviation.

[0182] The storage unit 1420 may include a readable medium in the form of a volatile storage unit, such as a random access storage unit (RAM) 14201 and / or a cache storage unit 14202 , and may further include a read-only storage unit (ROM) 14203 .

[0183] The storage unit 1420 may also include a program / utility 14204 having a set (at least one) of program modules 14205, such program modules 14205 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0184] Bus 1430 may represent one or more of several types of bus structures, including a memory unit bus or memory unit controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

[0185] The electronic device 1400 may also communicate with one or more external devices 1440 (e.g., keyboards, pointing devices, Bluetooth devices, etc.), one or more devices that enable a user to interact with the system 1400, and / or any device that enables the electronic device 1400 to communicate with one or more other computing devices (e.g., routers, modems, etc.). Such communication may be performed via an input / output (I / O) interface 1450. Furthermore, the system 1400 may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) via a network adapter 1460. Fig.14 As shown, the network adapter 1460 communicates with other modules of the electronic device 1400 via the bus 1430. It should be understood that, although not shown in the figure, other hardware and / or software modules can be used in conjunction with the electronic device 1400, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0186] Through the description of the above implementation, it is easy for those skilled in the art to understand that the example implementation described here can be implemented by software, or by software combined with necessary hardware. Therefore, the technical solution according to the implementation of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, including several instructions to enable a computing device (which can be a personal computer, a server, a terminal device, or a network device, etc.) to execute the method according to the implementation of the present disclosure.

[0187] In an exemplary embodiment of the present disclosure, a computer-readable storage medium is also provided, and the computer-readable storage medium may be a readable signal medium or a readable storage medium. Fig.15 A schematic diagram of a computer-readable storage medium provided in an embodiment of the present disclosure is shown. Fig.15 As shown, a program product capable of implementing the above method of the present disclosure is stored on the computer-readable storage medium 1500. In some possible implementations, various aspects of the present invention may also be implemented in the form of a program product, which includes a program code. When the program product is run on a user device, the program code is used to enable the user device to execute the steps according to various exemplary implementations of the present invention described in the above “Exemplary Method” section of this specification.

[0188] The program product for implementing the above method according to an embodiment of the present invention may adopt a portable compact disk read-only memory (CD-ROM) and include program code, and may be run on a user device, such as a personal computer. However, the program product of the present invention is not limited thereto, and in this document, a readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, apparatus, or device.

[0189] The program product may use any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0190] Computer readable signal media may include data signals propagated in baseband or as part of a carrier wave, in which readable program code is carried. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Readable signal media may also be any readable medium other than a readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0191] The program code embodied on the readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination of the foregoing.

[0192] Program code for performing the operations of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving a remote computing device, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., through the Internet using an Internet service provider).

[0193] It should be noted that, although several modules or units of the device for action execution are mentioned in the above detailed description, this division is not mandatory. In fact, according to the embodiments of the present disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. On the contrary, the features and functions of one module or unit described above can be further divided into multiple modules or units to be embodied.

[0194] In addition, although the steps of the method in the present disclosure are described in a specific order in the drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps, etc.

[0195] Through the description of the above implementation, it is easy for those skilled in the art to understand that the example implementation described here can be implemented by software, or by software combined with necessary hardware. Therefore, the technical solution according to the implementation of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, including several instructions to enable a computing device (which can be a personal computer, a server, a mobile terminal, or a network device, etc.) to execute the method according to the implementation of the present disclosure.

[0196] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A method for monitoring the thickness of the side wall film, It is characterized in that include: Providing a substrate, wherein a device region is formed on the surface of the substrate, and the device region includes a plurality of initial functional structures periodically arranged along a first direction; Using an online measuring device to measure the pre-selected initial functional structure to obtain an initial critical dimension of the initial functional structure; forming a target film layer on the sidewall of the preselected initial functional structure to obtain a target functional structure; Measuring the target functional structure using an online measuring device to obtain a target critical dimension of the target functional structure; Obtaining a measured thickness of the target film layer according to the initial critical dimension and the target critical dimension; Slicing the target functional structure to obtain the slice thickness of the target film layer, and determining the measurement deviation of the target film layer by the online measurement device according to the difference between the measured thickness of the target film layer and the slice thickness; A substrate to be tested is provided, wherein the device region of the substrate to be tested includes a plurality of the initial functional structures, and a statistical process control table is established to monitor the measured thickness of a target film layer formed on the side wall of the initial functional structure of the substrate to be tested by the online measuring device in combination with the measurement deviation.

2. The method according to claim 1, It is characterized in that The initial critical dimension includes a width of a single initial functional structure in a first direction, and the target critical dimension includes a width of a single target functional structure in the first direction; Alternatively, the initial critical dimension includes the spacing between adjacent initial functional structures in the first direction, and the target critical dimension includes the spacing between adjacent target functional structures in the first direction.

3. The method according to claim 1, It is characterized in that The target film layer includes a plurality of sub-target film layers; the target critical dimension includes a plurality of sub-target critical dimensions, wherein one sub-target film layer corresponds to one sub-target critical dimension.

4. The method according to claim 1, It is characterized in that When the pre-selected initial functional structure is measured using an online measuring device, the pre-selected initial functional structure is determined by: Selecting an image of a device region whose initial functional structure meets preset requirements as a field of view image; According to the preset design period of the initial functional structure, an initial functional structure whose period satisfies a first preset value range is determined in the field of view image as the pre-selected initial functional structure.

5. The method according to claim 4, It is characterized in that An initial functional structure that meets the preset requirements, including at least one of the following: The line edge roughness of the initial functional structure is less than 0.3 nm; The line width roughness of the initial functional structure is less than 0.3 nm; The critical dimension consistency of the initial functional structure is less than 0.

2.

6. The method according to claim 4, It is characterized in that The step of determining, in the field of view image, an initial functional structure whose period satisfies a first preset value range according to a preset design period of the initial functional structure comprises: The online measuring device is used to measure the first initial functional structure and the second initial functional structure in the field of view image to obtain the period of the initial functional structure, wherein the period of the initial functional structure is a first distance between an edge of the first initial functional structure and an edge corresponding to the second initial functional structure, or a second distance between a center of the first initial functional structure and a center corresponding to the second initial functional structure, and the first initial functional structure and the second initial functional structure are two adjacent initial functional structures; If the first distance and the second distance are within the first preset value range, the first initial functional structure or the second initial functional structure is used as the pre-selected initial functional structure.

7. The method according to claim 6, It is characterized in that The method further comprises: If the first distance and / or the second distance are not within the first preset value range, the measurement parameters of the online measurement device are adjusted until the measured first distance and second distance are within the first preset value range.

8. The method according to claim 7, It is characterized in that The method further comprises: If the first distance and / or the second distance measured by adjusting the measurement parameters of the online measurement device is not within the first preset value range, a field of view image that meets the preset requirements is screened in an adjacent device area.

9. The method according to claim 1, It is characterized in that The method of measuring the pre-selected initial functional structure using an online measuring device to obtain the initial critical dimensions of the initial functional structure includes: Using an online measuring device to measure a plurality of measuring points of the pre-selected initial functional structure along a second direction to obtain a plurality of process critical dimensions; An average value of the plurality of process critical dimensions is calculated to obtain an initial critical dimension of the initial functional structure.

10. The method according to claim 9, It is characterized in that Before calculating the average value of the plurality of process critical dimensions to obtain the initial critical dimension of the initial functional structure, the method further comprises: Determine whether there are multiple process critical dimensions that are not within the second preset value range; If so, redefining the initial functional structure within the device region; If not, the operation of calculating the average value of the plurality of process critical dimensions to obtain the initial critical dimension of the initial functional structure is performed.

11. The method according to claim 3, It is characterized in that The slice thickness of the target film layer includes the total slice thickness of the target film layer and the actual slice thickness of the sub-target film layer. Wherein, determining the measurement deviation of the target film layer by the online measurement device according to the difference between the measured thickness of the target film layer and the slice thickness includes: Calculating the difference between the measured thickness of the target film layer and the total thickness of the slice; If the difference exceeds a preset deviation range, the measurement parameters of the online measurement device are adjusted until the difference between the re-measured measured thickness of the target film layer and the total thickness of the slice is within the preset deviation range.

12. The method according to claim 11, It is characterized in that The method further comprises: If the difference does not exceed the preset deviation range, determining the total measurement deviation of the online measurement device on the target film layer according to the difference; The thickness measurement deviation of each sub-target film layer by the online measurement equipment is determined in sequence according to a preset order.

13. A system for monitoring the thickness of a sidewall film. It is characterized in that include: A film deposition device, used for forming a target film layer on the side wall of an initial functional structure of a substrate to obtain a target functional structure, wherein a device region is formed on the surface of the substrate, and the device region includes a plurality of initial functional structures periodically arranged along a first direction; forming a target film layer on the sidewall of an initial functional structure provided on a substrate to be tested, wherein a device region of the substrate to be tested includes a plurality of the initial functional structures periodically arranged along a first direction; An online measuring device is used to measure the initial functional structure preselected on the substrate to obtain the initial critical size of the initial functional structure; Measuring the target functional structure on the substrate to obtain the target critical size of the target functional structure; measuring the slice of the target functional structure on the substrate to obtain the slice thickness of the target film layer; A data processing device, communicating with the online measurement device, is used to obtain the measured thickness of the target film layer according to the initial critical dimension and the target critical dimension; and to determine the measurement deviation of the target film layer by the online measurement device according to the difference between the measured thickness of the target film layer and the slice thickness; A statistical process control table is established to monitor the measured thickness of a target film layer formed on the side wall of the initial functional structure of the substrate to be tested by the online measurement device in combination with the measurement deviation.

14. The system according to claim 13, It is characterized in that The data processing device communicates with the film deposition device, wherein: The data processing device is further used to send the measured thickness variation trend of the target film layer of the substrate to be tested to the film layer deposition device; The film deposition equipment is also used to adjust process parameters according to the variation trend of the measured thickness so that the measured thickness of the target film layer meets the process requirements.

15. An electronic device, It is characterized in that include: processor; and a memory for storing executable instructions of the processor; wherein the processor is configured to execute the method for monitoring the thickness of a sidewall film layer as described in any one of claims 1 to 12 by executing the executable instructions.

16. A computer-readable storage medium having a computer program stored thereon, It is characterized in that When the computer program is executed by a processor, the method for monitoring the thickness of a sidewall film layer as described in any one of claims 1 to 12 is implemented.

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