Semiconductor measuring structure and semiconductor grinding amount measuring method

Abstract

The invention relates to the technical field of semiconductors, and discloses a semiconductor measuring structure and a semiconductor grinding amount measuring method. The semiconductor measurement structure is arranged on the wafer, and the semiconductor measurement structure at least comprises a groove area and a grinding area; wherein the top surface of the grinding area is higher than the top surface of the groove area, and the side wall of the grinding area and the top surface of the groove area are encircled to form a measuring groove; the grinding amount of the grinding area is determined by measuring the step difference between the grinding area and the top surface of the groove area before and after chemical mechanical polishing process treatment. The optical interference can be avoided, so that the measurement value of the grinding amount of the chemical mechanical polishing process is prevented from being influenced, the measurement deviation between the actual value and the measurement value is reduced, and the measurement precision is improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, for example, to a semiconductor measurement structure and a semiconductor polishing amount measurement method. Background Art

[0002] In recent years, MRAM (Magnetic Random Access Memory) has gradually become the development direction of new memory in the future due to its high speed, low power consumption, non-volatility and other characteristics. In the MRAM manufacturing process, the chemical mechanical polishing (CMP) process is often used. How to evaluate whether the process meets the process standards (for example, how to evaluate the grinding amount of the chemical mechanical polishing process) is a key technology in the chemical mechanical polishing process.

[0003] The related art discloses a method for measuring a chemical mechanical polishing process, in which the film thickness of a test key is measured by an optical measuring machine (such as an ellipsometer) commonly used in wafer manufacturing plants to represent the actual thickness of the corresponding film layer in the corresponding area, and then the grinding amount of the chemical mechanical polishing process is evaluated based on the thickness value monitored in real time.

[0004] In the process of implementing the embodiments of the present disclosure, it is found that there are at least the following problems in the related art: Optical measurement is easily affected by factors such as the undulation and unevenness of the underlying film layer and the thickness of the film layer deposition, which can easily affect the measured value of the grinding amount in the chemical mechanical polishing process, causing a measurement deviation between the measured value and the actual value, thereby affecting the measurement accuracy. Summary of the invention

[0005] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical elements or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0006] The disclosed embodiments provide a semiconductor measurement structure and a semiconductor polishing amount measurement method to avoid optical interference, thereby avoiding affecting the measured value of the polishing amount in the chemical mechanical polishing process, reducing the measurement deviation between the actual value and the measured value, and thus improving the measurement accuracy.

[0007] In some embodiments, the semiconductor measurement structure is arranged on a wafer, and the semiconductor measurement structure includes at least a groove area and a grinding area; wherein the top surface of the grinding area is higher than the top surface of the groove area, and the side wall of the grinding area and the top surface of the groove area are surrounded by a measurement groove; the grinding amount of the grinding area is determined by measuring the step difference between the grinding area and the top surface of the groove area before and after the chemical mechanical polishing process.

[0008] Optionally, the step difference measuring instrument includes at least: a step profiler or an atomic force microscope.

[0009] Optionally, the grinding area is configured as a film layer structure, and the film layer types of the grinding area include a single type or multiple types.

[0010] Optionally, the number of semiconductor measurement structures is set to one or more.

[0011] Optionally, the size of the measuring groove is determined by the size of the abrasive particles in the polishing liquid, so that the line width of the measuring groove is smaller than the diameter of the abrasive particles.

[0012] Optionally, the depth of the measuring groove is determined by the size of the abrasive in the polishing liquid and the line width of the measuring groove, so that the height difference between the lowest point where the abrasive penetrates into the measuring groove and the top surface of the polishing area before and after the chemical mechanical polishing process is less than the depth of the measuring groove.

[0013] The semiconductor measurement structure provided by the embodiments of the present disclosure can achieve the following technical effects: A semiconductor measurement structure is formed on the wafer. The semiconductor measurement structure is a measurement groove formed by the groove area and the grinding area. Since the top surface of the grinding area is higher than the top surface of the groove area, the grinding area and the groove area are stepped through the measurement groove, so that the step value here can be measured by a step meter or an atomic force microscope (AFM). Before the chemical mechanical polishing process, the step value between the top surface of the grinding area and the groove area is measured as the pre-step value. After the chemical mechanical polishing process, the step value between the top surface of the grinding area and the groove area is measured as the post-step value. The difference between the pre-step value and the post-step value can be used to determine the grinding amount of the grinding area, and the grinding amount can be used as the measurement value of the grinding amount of the chemical mechanical polishing process. When there is non-uniformity (e.g., micro-undulation) on the bottom surface of the wafer, conventional optical measurement will generate optical interference (e.g., diffuse reflection and other interference) due to the non-uniformity of the bottom surface of the wafer, thereby causing measurement deviation and affecting the measurement accuracy. However, the embodiment of the present disclosure adopts the step difference measurement method as shown above, not optical measurement, and only needs to measure the step difference before and after the chemical mechanical polishing process to obtain the measurement value, which is not affected by the uniformity of the bottom surface of the wafer, thereby making the measurement result more accurate. Furthermore, optical measurement is also limited by the difficulty in measuring metal materials and unknown optical film layer information, but the measurement method provided by the embodiment of the present disclosure is not limited by the film material of the semiconductor measurement structure, and when there is no optical film layer information of the corresponding film layer, the semiconductor measurement structure of the present application can still be used for measurement, so the semiconductor measurement structure of the present application has a wider range of applications. In addition, compared with the equipment cost of the optical measurement machine, the equipment cost of the equipment for measuring step differences (such as step meters, atomic force microscopes, etc.) is lower, so the present application can significantly reduce the measurement cost.

[0014] In some embodiments, the semiconductor grinding amount measurement method at least includes: forming a semiconductor measurement structure on a wafer; wherein the semiconductor measurement structure at least includes a groove area and a grinding area; the top surface of the grinding area is higher than the top surface of the groove area, and the side wall of the grinding area and the top surface of the groove area are surrounded by a measuring groove; and the grinding amount of the grinding area is determined by measuring the step difference between the grinding area and the top surface of the area before and after the chemical mechanical polishing process.

[0015] Optionally, before one or more chemical mechanical polishing processes in the wafer manufacturing process, one or more corresponding measuring grooves are formed, and each measuring groove is formed by enclosing the corresponding grinding area side wall and the top surface of the corresponding groove area; by measuring the step difference corresponding to the measuring groove before and after the corresponding chemical mechanical polishing process, the grinding amount of the corresponding grinding area is determined.

[0016] Optionally, forming a measuring groove includes at least: a first preceding process is further included before the chemical mechanical polishing process; before the first preceding process, a preset size of the initial groove is determined to be a first size, and the first size is the same as the preset size of the measuring groove; through the first preceding process, a preset change amount of the preset size of the initial groove is adjusted to a second size by the first preceding process, so that the vector sum of the second size and the preset change amount is equal to the first size; forming the initial groove according to the second size; executing the first preceding process to change the actual size of the initial groove from the second size to the first size, thereby forming the measuring groove.

[0017] Optionally, forming the measurement groove at least includes: a second pre-process before the chemical mechanical polishing process; and directly forming the measurement groove in the second pre-process according to a preset size of the measurement groove.

[0018] The semiconductor polishing amount measurement method provided by the embodiment of the present disclosure can achieve the following technical effects: A semiconductor measurement structure is formed on a wafer. The semiconductor measurement structure is a measurement groove formed by a groove area and a grinding area. Since the top surface of the grinding area is higher than the top surface of the groove area, the grinding area and the groove area are stepped through the measurement groove, so that the step value here can be measured by a step meter or an atomic force microscope. Before the chemical mechanical polishing process, the step value between the top surface of the grinding area and the groove area is measured as the pre-step value. After the chemical mechanical polishing process, the step value between the top surface of the grinding area and the groove area is measured as the post-step value. The grinding amount of the grinding area can be determined by the difference between the pre-step value and the post-step value, and the grinding amount can be used as the measurement value of the grinding amount of the chemical mechanical polishing process. When there is non-uniformity (e.g., micro-undulation) on the bottom surface of the wafer, conventional optical measurement will generate optical interference (e.g., diffuse reflection and other interference) due to the non-uniformity of the bottom surface of the wafer, thereby causing measurement deviation and affecting the measurement accuracy. However, the embodiment of the present disclosure adopts the step difference measurement method as shown above, not optical measurement, and only needs to measure the step difference before and after the chemical mechanical polishing process to obtain the measurement value, which is not affected by the uniformity of the bottom surface of the wafer, thereby making the measurement result more accurate. Furthermore, optical measurement is also limited by the difficulty in measuring metal materials and unknown optical film layer information, but the measurement method provided by the embodiment of the present disclosure is not limited by the film material of the semiconductor measurement structure, and when there is no optical film layer information of the corresponding film layer, the semiconductor measurement structure of the present application can still be used for measurement, so the semiconductor measurement structure of the present application has a wider range of applications. In addition, compared with the equipment cost of the optical measurement machine, the equipment cost of the equipment for measuring step differences (such as step meters, atomic force microscopes, etc.) is lower, so the present application can significantly reduce the measurement cost.

[0019] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] One or more embodiments are exemplarily described by corresponding drawings, which do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements, and the drawings do not constitute a scale limitation, and wherein: Figure 1 1 is a cross-sectional view of a semiconductor measurement structure provided by an embodiment of the present disclosure before and after being processed by a chemical mechanical polishing process.

[0021] Figure 2 is a cross-sectional view of another semiconductor measurement structure provided by an embodiment of the present disclosure before and after being processed by a chemical mechanical polishing process.

[0022] Figure 3 It is a cross-sectional view of a semiconductor measurement structure including only a single film layer provided by an embodiment of the present disclosure.

[0023] Figure 4 It is a cross-sectional view of a semiconductor measurement structure including multiple types of film layers provided by an embodiment of the present disclosure.

[0024] Figure 5 It is a cross-sectional view of the spacing between film layers of the same type in a semiconductor measurement structure provided by an embodiment of the present disclosure.

[0025] Figure 6 It is a cross-sectional view of continuous arrangement of film layers of the same type in a semiconductor measurement structure provided by an embodiment of the present disclosure.

[0026] Figure 7 1 is a top view of a semiconductor measurement structure including an annular measurement trench provided by an embodiment of the present disclosure.

[0027] Figure 8 1 is a top view of a semiconductor measurement structure including strip-shaped and cross-shaped measurement grooves provided by an embodiment of the present disclosure.

[0028] Fig. 9 It is a schematic diagram of abrasive grain size and measured groove line width in a chemical mechanical polishing process provided by an embodiment of the present disclosure.

[0029] Fig.10 It is a schematic diagram of abrasive grain size and measured groove depth in a chemical mechanical polishing process provided by an embodiment of the present disclosure.

[0030] Fig.11 It is a schematic diagram of a semiconductor polishing amount measurement method provided by an embodiment of the present disclosure.

[0031] Fig.12 It is a schematic diagram of a formation process of a measurement groove provided by an embodiment of the present disclosure.

[0032] Reference numerals: 1: Grinding area; 2: Groove area; 3: Measuring groove; 4: Abrasive particles. DETAILED DESCRIPTION

[0033] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0034] The terms "first", "second", etc. in the description of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so as to describe the embodiments of the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0035] In the embodiments of the present disclosure, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the embodiments of the present disclosure and their embodiments, and are not intended to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction. Moreover, in addition to being used to indicate directions or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0036] Unless otherwise stated, the term "plurality" means two or more.

[0037] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other.

[0038] In recent years, MRAM has gradually become the development direction of new memory in the future due to its high speed, low power consumption, non-volatility and other characteristics. In the MRAM manufacturing process, the chemical mechanical polishing process is often used. How to evaluate whether the process meets the process standards (for example, how to evaluate the grinding amount of the chemical mechanical polishing process) is a key technology in the chemical mechanical polishing process.

[0039] The related art discloses a method for measuring a chemical mechanical polishing process, in which the film thickness of a test unit is measured by an optical measuring machine (such as an ellipsometer) commonly used in wafer manufacturing plants to represent the actual thickness of the corresponding film layer in the corresponding area. The grinding amount of the chemical mechanical polishing process is then evaluated based on the thickness value monitored in real time.

[0040] In the process of implementing the embodiments of the present disclosure, it is found that there are at least the following problems in the related art: Optical measurement methods are easily affected by factors such as the undulation and unevenness of the underlying film layer and the thickness of the film layer deposition, which can easily affect the measured value of the grinding amount in the chemical mechanical polishing process, resulting in measurement deviation, thereby affecting the measurement accuracy.

[0041] The factors affecting the measured value of the grinding amount by the optical measurement method include, but are not limited to, the following situations: First, the underlying film layer of the wafer being measured is undulating, and there is an uneven problem on the surface of the film layer, which causes interference such as diffuse reflection during optical measurement, thereby affecting the measured value of the grinding amount. Second, the thickness of the film deposition on the wafer being measured affects light transmittance, thereby affecting the measured value of the grinding amount. Third, the film material of the wafer being measured includes metal materials that are difficult to transmit light, thereby affecting the measured value of the grinding amount. Fourth, there are multiple types of film layers on the wafer being measured, and the adjacent interfaces between different types of film layers will aggravate the degree of complex reflection, refraction, scattering and other phenomena, thereby affecting the measured value of the grinding amount. The influencing factors listed in the embodiments of the present disclosure are only exemplary statements. The influencing factors in the actual measurement process include, but are not limited to, the influencing factors listed in the embodiments of the present disclosure, which will not be repeated here.

[0042] It should be noted that the semiconductor measurement structure and semiconductor polishing amount measurement method used in the embodiments of the present disclosure are not limited to the manufacturing process of MRAM, but are also applicable to the manufacturing processes of other devices other than MRAM, such as the manufacturing process of CMOS (Complementary Metal-Oxide-Semiconductor) devices.

[0043] Combination Figure 1 and Figure 2As shown, an embodiment of the present disclosure provides a semiconductor measurement structure, which is arranged on a wafer, and the semiconductor measurement structure at least includes a groove area 2 and a grinding area 1; wherein the top surface of the grinding area 1 is higher than the top surface of the groove area 2, and the side wall of the grinding area 1 and the top surface of the groove area 2 are surrounded to form a measurement groove 3; the grinding amount of the grinding area 1 is determined by measuring the step difference between the top surfaces of the grinding area 1 and the groove area 2 before and after the chemical mechanical polishing process.

[0044] It should be noted that the top surface of the groove region 2 is the bottom of the measuring groove 3 , and the sidewall of the polishing region 1 is the sidewall of the measuring groove 3 .

[0045] A semiconductor measurement structure provided by an embodiment of the present disclosure is used to form a semiconductor measurement structure on a wafer. The semiconductor measurement structure is formed by a measurement groove 3 formed by a groove area 2 and a grinding area 1. Since the top surface of the grinding area 1 is higher than the top surface of the groove area 2, the grinding area 1 and the groove area 2 are stepped through the measurement groove 3, so that the step value here can be measured by a step meter or an atomic force microscope. Before the chemical mechanical polishing process, the step value between the top surfaces of the grinding area 1 and the groove area 2 is measured as the pre-step value. After the chemical mechanical polishing process, the step value between the top surfaces of the grinding area 1 and the groove area 2 is measured as the post-step value. The grinding amount of the grinding area 1 can be determined by the difference between the pre-step value and the post-step value, and the grinding amount can be used as the measurement value of the grinding amount of the chemical mechanical polishing process. When there is non-uniformity (e.g., micro-undulation) on the bottom surface of the wafer, conventional optical measurement will generate optical interference (e.g., diffuse reflection and other interference) due to the non-uniformity of the bottom surface of the wafer, thereby causing measurement deviation and affecting the measurement accuracy. However, the embodiment of the present disclosure adopts the step difference measurement method as shown above, not optical measurement, and only needs to measure the step difference before and after the chemical mechanical polishing process to obtain the measurement value, which is not affected by the uniformity of the bottom surface of the wafer, thereby making the measurement result more accurate. Furthermore, optical measurement is also limited by the difficulty in measuring metal materials and unknown optical film layer information, but the measurement method provided by the embodiment of the present disclosure is not limited by the film material of the semiconductor measurement structure, and when there is no optical film layer information of the corresponding film layer, the semiconductor measurement structure of the embodiment of the present disclosure can still be used for measurement, so the semiconductor measurement structure of the embodiment of the present disclosure has a wider range of applications. In addition, compared with the equipment cost of the optical measurement machine, the equipment cost of the equipment for measuring step differences (such as step gauges, atomic force microscopes, etc.) is lower, so the embodiment of the present disclosure can significantly reduce the measurement cost.

[0046] It should be noted that at least one semiconductor measurement structure and at least one core functional area are formed on the wafer based on the same manufacturing process. Among them, the core functional area is the area of ​​the actual chip production and manufacturing process and the final formed area, such as the integrated circuit area, the cutting road area, etc. In the actual preparation process of semiconductor devices, due to different manufacturing requirements, the positional relationship between the semiconductor measurement structure and the core functional area includes but is not limited to the semiconductor measurement structure being arranged around the core functional area, the semiconductor measurement structure being interspersed in the core functional area, etc. When the wafer is ground by a chemical mechanical polishing process, the grinding amount of the above-mentioned grinding area 1 can represent the grinding amount of the grinding area 1 of the semiconductor measurement structure. When the top surface height of part or all of the core functional area is the same as the top surface height of the semiconductor measurement structure, the grinding amount of the above-mentioned grinding area 1 can also represent the grinding amount of this part or all of the core functional area, that is, it can represent the grinding amount of the chemical mechanical polishing process.

[0047] Specific, combined Figure 1 and Figure 2 , measuring the step difference between the top surfaces of the grinding area 1 and the groove area 2 before and after the chemical mechanical polishing process, which is the difference between the pre-step value h1 between the top surfaces of the grinding area 1 and the groove area 2 before the chemical mechanical polishing process and the post-step value h2 between the top surfaces of the grinding area 1 and the groove area 2 after the chemical mechanical polishing process.

[0048] Specifically, the chemical mechanical polishing process at least includes: interlayer dielectric chemical mechanical polishing (ILD CMP).

[0049] Optionally, the step difference measuring instrument includes at least: a step meter or an atomic force microscope. It should be noted that the step meter in the embodiment of the present disclosure includes a mechanical probe step meter. In this way, the working principle of the step meter is to directly contact the surface of the film layer to be measured through the probe. When the probe moves on the surface of the film layer to be measured, due to the presence of steps or height changes on the surface of the film layer to be measured, the probe will move up and down accordingly, and the step value of the surface of the film layer to be measured is obtained by measuring the vertical displacement of the probe. The working principle of the atomic force microscope is based on the force between atoms. The probe is scanned on the surface of the film layer to be measured. When the distance between the probe and the atoms on the surface of the film layer to be measured changes, the atomic force will change accordingly. The step value of the surface of the film layer to be measured is obtained by detecting the change in atomic force. In this way, the measurement value of the step meter depends only on the vertical displacement of the probe, and the measurement value of the atomic force microscope depends only on the change of atomic force. Both do not involve optical measurement methods. Therefore, the measurement method provided by the embodiment of the present disclosure is not limited by the uniformity of the underlying film layer and the material of the film layer being measured. For example, when there is an opaque metal film layer in the grinding area 1, the grinding amount of the grinding area 1 can still be accurately measured, so it has a wider range of applications.

[0050] Optionally, the grinding area 1 involved in the embodiment of the present disclosure is set as a film structure. Considering that during the manufacturing process, due to different manufacturing requirements, the types of film layers formed on the wafer may also be different, therefore, the types of film layers in the grinding area 1 may include a single type or multiple types. Figure 3-Figure 6 Schematic diagram of film types shown, in which some Figure 3 In the embodiment shown, the film type of the grinding area 1 includes a single type, such as a first type of film layer (such as a first dielectric layer). Figure 4 In the embodiment shown, the types of film layers in the grinding area 1 include multiple types, such as a substrate layer, a first dielectric layer, a magnetic tunnel junction film layer, a second dielectric layer, and a third dielectric layer stacked in sequence from bottom to top. Figure 5 and Figure 6 In the illustrated embodiment, the types of film layers in the grinding area 1 include multiple types, such as a substrate layer, a first type of film layer, a second type of film layer, and a third type of film layer stacked in sequence from bottom to top. Considering that in the actual manufacturing process of semiconductor devices, different film layers may be deposited on the wafer based on different process requirements, it can be seen from the above embodiments that the measurement method provided by the embodiment of the present disclosure can be applied to different film layers formed by different preparation processes, and is not limited by the type of film layer. It can realize the grinding amount measurement of a single type of film layer, and can also realize the grinding amount measurement of multiple types of film layers, and has a wider range of applications.

[0051] Specifically, in the actual manufacturing process of semiconductor devices, based on different process requirements, the types of film layers may include multiple types. Due to the differences in optical properties (such as refractive index, extinction coefficient, etc.) between different types of film layers, when performing traditional optical measurements, complex reflection, refraction and scattering phenomena occur at the interfaces of different film layers, resulting in inaccurate measurement results. In addition, stacking multiple types of film layers will cause the film layer to become thicker, exacerbating the non-uniformity of the optical properties of the film layer (such as the change in refractive index with depth, etc.), which will also cause inaccurate measurement results. Since the embodiment of the present disclosure does not involve optical measurement, the instrument for measuring the step value in the embodiment of the present disclosure is a step meter or an atomic force microscope, and the measurement value depends only on the vertical displacement of the probe or the change in atomic force. The measurement method provided in the embodiment of the present disclosure can be applied to film layers of multiple types and thicknesses formed due to the preparation process, and is not limited by the number of film layer types and the thickness of the film layer. Therefore, the scope of application of the embodiment of the present disclosure is wider.

[0052] Specifically, in the actual manufacturing process of semiconductor devices, based on different process requirements, among the film layer types in the grinding area 1, at least one film layer can be set to be a metal film layer, a metal oxide film layer or a metal nitride film layer, and the film layer thickness is greater than or equal to 50nm.

[0053] In this way, due to the high electron density and strong absorption and scattering characteristics of metals, when light is transmitted through metal films by traditional optical measurement, it will interact strongly with the electrons in the metal, resulting in a large amount of light being absorbed and scattered, so that its light transmittance is regarded as tending to be opaque, and the transmission intensity will not be detected by traditional optical measurement instruments. However, since the instrument used to measure the step value in the embodiment of the present disclosure is a step meter or an atomic force microscope, the measurement value depends only on the vertical displacement of the probe or the change in atomic force. The measurement method provided by the embodiment of the present disclosure can be applied to a variety of film materials and film layers of various thicknesses formed by the preparation process, and is not limited by the film material and thickness. Therefore, the scope of application of the embodiment of the present disclosure is wider.

[0054] Optionally, the groove area 2 involved in the embodiment of the present disclosure is set as a film layer structure. Considering that the types of film layers formed on the wafer may be different due to different manufacturing requirements during the manufacturing process, the types of film layers in the groove area 2 may include a single type or multiple types. Among them, the type of film layer in the groove area 2 is exactly the same as the type of film layer in the grinding area 1, or partially the same, or completely different. It only needs to ensure that the top surface of the grinding area 1 is higher than the top surface of the groove area 2, and the grinding area 1 and the groove area 2 can be enclosed as a measuring groove 3. For example Figure 3-Figure 6 The schematic diagram of the film types shown in the figure is used in some Figure 3 In the embodiment shown, the film types of the trench region 2 are all of a single type, such as a first type of film layer (eg, a first dielectric layer). Figure 4In the embodiment shown, the film layer types of the trench region 2 include multiple types, such as a substrate layer, a first dielectric layer, and a third dielectric layer stacked in sequence from bottom to top. Figure 5 and Figure 6 In the embodiment shown, the types of film layers in the groove region 2 include multiple types, such as a substrate layer, a first type of film layer, and a third type of film layer stacked in sequence from bottom to top. In this way, considering that in the actual manufacturing process of semiconductor devices, different film layers may be deposited on the wafer based on different process requirements, it can be seen from the above embodiments that the measurement method provided by the embodiment of the present disclosure can be applied to different film layers formed by different preparation processes, and it is not limited by the type of film layer, and can realize the grinding amount measurement of a single type of film layer, and can also realize the grinding amount measurement of multiple types of film layers, and has a wider range of applications.

[0055] In some Figure 3 In the illustrated embodiment, when the measuring groove 3 is formed in the case of a single type of film layer, the type of the film layer in the groove region 2 is exactly the same as the type of the film layer in the grinding region 1, and photolithography and etching are used to make the film layer thickness in the groove region 2 smaller than the film layer thickness in the grinding region 1, thereby forming the measuring groove 3. At this time, the top surface height of the grinding region 1 is higher than the top surface height of the groove region 2, so as to be used for the subsequent measurement of the grinding amount.

[0056] In other Figure 4 In the embodiment shown, when the measurement groove 3 is formed in the case of multiple types of film layers, the initial film layers of the groove region 2 and the grinding region 1 are of the same type, which are the substrate layer, the first dielectric layer, and the magnetic tunnel junction film layer. The magnetic tunnel junction film layer of the groove region 2 is removed by photolithography and etching, so that the film thickness of the groove region 2 is less than the film thickness of the grinding region 1, and the initial groove is formed. At this time, the top surface height of the grinding region 1 is higher than the top surface height of the groove region 2. Then, the third dielectric layer is continuously deposited on the initial groove. At this time, the film thickness of the groove region 2 is still less than the film thickness of the grinding region 1. The initial groove is formed into the measurement groove 3. At this time, the top surface height of the grinding region 1 is higher than the top surface height of the groove region 2, so as to be used for the subsequent grinding amount measurement.

[0057] In other Figure 5In the illustrated embodiment, when forming the measurement groove 3 in the case of multiple types of film layers, a substrate layer is first deposited on the wafer, and then multiple layers of the first type of film layers are continuously deposited, and then multiple layers of the second type of film layers are continuously deposited as the initial film layers of the groove area 2 and the grinding area 1. The second type of film layer in the groove area 2 is removed by photolithography and etching to form an initial groove. At this time, the type of the film layer in the groove area 2 is partially the same as the type of the film layer in the grinding area 1, the thickness of the film layer in the groove area 2 is less than the thickness of the film layer in the grinding area 1, and the top surface height of the grinding area 1 is higher than the top surface height of the groove area 2. Then, multiple layers of the third type of film layer are continuously deposited on the initial groove. After deposition, the thickness of the film layer in the groove area 2 is still less than the thickness of the film layer in the grinding area 1. The initial groove is formed into a measurement groove 3. At this time, the top surface height of the grinding area 1 is higher than the top surface height of the groove area 2, which is used for subsequent grinding amount measurement.

[0058] In other Figure 6 In the illustrated embodiment, when a measuring groove 3 is formed in the case of multiple types of film layers, a substrate layer is first deposited on the wafer, and then a first type of film layer and a second type of film layer are deposited at intervals, so that the wafer is stacked from bottom to top with a substrate layer, a first type of film layer, a second type of film layer, a first type of film layer, and a second type of film layer as initial film layers of the groove area 2 and the grinding area 1. The two layers of the second type of film layers in the groove area 2 and the first type of film layer arranged between the measuring second type of film layers are removed by photolithography and etching to form an initial groove. At this time, the type of film layer in the groove area 2 is partially the same as the type of film layer in the grinding area 1, the film layer thickness in the groove area 2 is less than the film layer thickness in the grinding area 1, and the top surface height of the grinding area 1 is higher than the top surface height of the groove area 2. Then, a third type of film layer is deposited on the initial groove. After deposition, the film thickness of the groove area 2 is still smaller than the film thickness of the grinding area 1. The initial groove is formed into a measuring groove 3. At this time, the top surface height of the grinding area 1 is higher than the top surface height of the groove area 2 for subsequent grinding amount measurement.

[0059] Optional, reference Figure 6 As shown in the figure, in the actual preparation process of semiconductor devices, due to different manufacturing requirements, the types of film layers formed on the wafer may also exist in the following situations: (1) Figure 5 As shown, the same type of film layers are stacked continuously, and other types of film layers are not arranged between the same type of film layers; (2) as Figure 6 As shown, other types of film layers are arranged between the same type of film layers, as well as other situations not mentioned above.

[0060] Taking the above situation (1) as an example, when using traditional optical measurement, the multi-layer film stacking setting in the grinding area 1 may cause the film layer thickness to increase, affecting the light transmittance of the film layer, and causing inaccurate measurement results. The adjacent interfaces between different types of film layers will produce complex reflection, refraction, scattering and other phenomena, which will further cause inaccurate measurement results. However, the embodiment of the present disclosure does not have similar problems and can overcome the influence of the arrangement rules of the film layers in the grinding area 1 on the measurement accuracy. Using the measurement method of the embodiment of the present disclosure, the instrument for measuring the step value is a step meter or an atomic force microscope. The measurement value depends only on the vertical displacement of the probe or the change in atomic force, and is not limited by the number of adjacent interfaces between different film layers, and thus is not limited by the arrangement rules of the film layers. Therefore, the embodiment of the present disclosure further expands the scope of measurement application.

[0061] Taking the above situation (2) as an example, when the traditional optical measurement method is used to measure it, the number of adjacent interfaces between different film layers in the grinding area 1 will be further increased compared to situation (1), thereby aggravating the degree of complex reflection, refraction, scattering and other phenomena. If the traditional optical measurement is used, it will further cause the measurement result to be inaccurate. However, the embodiment of the present disclosure does not have similar problems and can overcome the influence of the arrangement rules of the film layers in the grinding area 1 on the measurement accuracy. Using the measurement method of the embodiment of the present disclosure, the instrument for measuring the step value is a step meter or an atomic force microscope. The measurement value depends only on the vertical displacement of the probe or the change of the atomic force, and is not limited by the number of adjacent interfaces between different film layers, and thus is not limited by the arrangement rules of the film layers, thereby further expanding the scope of measurement application.

[0062] It should be noted that for different manufacturing purposes, a single type of film layer or multiple types of film layers may be formed at different process stages. When the grinding amount needs to be measured at different process manufacturing stages, the measurement method used in the embodiment of the present disclosure is also applicable.

[0063] Optionally, the number of semiconductor measurement structures is set to one or more.

[0064] In this way, the number of measurement structures provided by the embodiment of the present disclosure is flexible. Based on different measurement purposes, those skilled in the art can set either a single one or multiple ones. When a single one is set, its position can be set around the core functional area, and the semiconductor measurement structure is interspersed in the core functional area. The semiconductor measurement structure can measure the grinding amount of the semiconductor measurement structure grinding area 1. When part or all of the top surface of the core functional area is at the same height as the top surface of the semiconductor measurement structure, it can also be used as the grinding amount of part or all of the core functional area. This avoids the problem of setting measurement structures at multiple locations on the wafer to achieve the whole wafer grinding amount measurement. It can simplify the measurement process to a certain extent and save the layout area. The area where the semiconductor measurement structure is not set can be fully designed as the core functional area, which is conducive to reducing the area of ​​the semiconductor measurement structure and improving the storage density of the wafer on the basis of ensuring the measurement accuracy.

[0065] Furthermore, when it is necessary to measure the polishing uniformity of the entire wafer, it is necessary to set up measurement structures in different regions of the wafer (i.e., set up multiple measurement structures). The measurement structure in each region can be used to measure the polishing amount of the region, thereby obtaining the polishing amount of different regions. Therefore, the polishing amount of multiple polishing regions 1 on the wafer can be detected, and the measurement of polishing uniformity analysis can be achieved.

[0066] Specifically, one or more exposure units (shots) are arranged on the wafer, and one or more semiconductor measurement structures are arranged on each exposure unit. Each exposure unit includes at least one core functional area. It should be noted that the exposure unit usually refers to the area covered by a photolithography machine for one exposure on the wafer, which usually needs to be smaller than the wafer size. When one exposure unit is arranged on the wafer, it means that the wafer is exposed once. When multiple exposure units are arranged on the wafer, it means that the wafer is exposed multiple times. More specifically, the semiconductor measurement structure can be arranged between adjacent exposure units, or it can be arranged on the cutting path area of ​​the exposure unit.

[0067] Thus, based on different manufacturing processes and manufacturing purposes, the number of exposure units provided by the embodiment of the present disclosure is flexible, and can be set to a single or multiple. The number of semiconductor measurement areas set on the exposure unit is also flexible.

[0068] When the number of exposure units is only one and the number of semiconductor measurement structures on the exposure unit is only one, it is beneficial to simplify the measurement process and improve the storage density of the exposure unit while ensuring the measurement accuracy.

[0069] When there is only one exposure unit and there are multiple semiconductor measurement structures on the exposure unit, it is beneficial to achieve the measurement of the polishing uniformity analysis of the exposure area.

[0070] When there are multiple exposure units and a single semiconductor measurement structure is provided on each exposure unit, the semiconductor measurement structure of each exposure unit can be used to measure the grinding amount of the corresponding exposure unit. Since the exposure units are usually evenly distributed in the manufacturing process, the grinding amounts of multiple evenly distributed grinding areas 1 on the wafer can be obtained, thereby improving the accuracy of the grinding uniformity analysis.

[0071] When there are multiple exposure units and multiple semiconductor measurement structures on each exposure unit, the semiconductor measurement structure of each exposure unit measures multiple measurement values ​​respectively, thereby further improving the accuracy of polishing uniformity analysis.

[0072] Optionally, for different manufacturing purposes, multiple chemical mechanical polishing processes may be used at different process stages, and the grinding amount measurement of each chemical mechanical polishing process corresponds to one or more semiconductor measurement structures, so that multiple semiconductor measurement structures are set on the wafer. In this way, the grinding amount of each chemical mechanical polishing process can be accurately measured.

[0073] Optional, reference Figure 7 and Figure 8 As shown, the shape of the top surface of the groove area 2 includes at least: annular, strip, and cross. It should be noted that "annular", "strip", and "cross" are only exemplary expressions, and the shape of the top surface of the actual groove area 2 includes but is not limited to the above three shapes, and its shape can be adjusted and set on the wafer according to actual needs, which will not be repeated here.

[0074] Optional, reference Fig. 9 As shown, the size of the measuring groove 3 is determined by the size of the abrasive grains 4 in the slurry, so that the line width CD of the measuring groove 3 is smaller than the diameter D of the abrasive grains 4 .

[0075] It should be noted that in actual production, due to the different manufacturing processes of the abrasive particles 4 in the grinding liquid, the shape of the abrasive particles 4 may be non-spherical. The abrasive particles 4 in the grinding liquid are equivalent to spheres, and their equivalent diameters can be used as the diameter D of the abrasive particles 4.

[0076] In this way, during the grinding process of the chemical mechanical polishing process, the chemical components in the grinding liquid are used to soften the film layer on the surface of the wafer. In addition, the abrasive particles 4 in the grinding liquid contact the film layer to be ground to produce a mechanical action to remove the film layer. If the line width of the measuring groove 3 is smaller than the diameter of the abrasive particles 4, the abrasive particles 4 cannot enter the measuring groove 3 and contact the bottom of the measuring groove 3 (i.e., the top surface of the groove area 2), thereby avoiding the chemical mechanical polishing process from grinding to the top surface of the groove area 2, reducing the damage to the top surface of the groove area 2, and making the top surface of the groove area 2 remain unchanged before and after the chemical mechanical polishing process, thereby improving the measurement accuracy of the step difference that needs to be measured before and after the chemical mechanical polishing process, thereby further improving the measurement accuracy of the grinding area 1 or the grinding amount of the chemical mechanical polishing process.

[0077] Optional, reference Fig.10 As shown, the depth of the measuring groove 3 is determined by the size of the abrasive 4 in the polishing liquid and the line width of the measuring groove 3, so that the height difference between the lowest point where the abrasive 4 penetrates into the measuring groove 3 and the top surface of the polishing area 1 before and after the chemical mechanical polishing process is less than the depth of the measuring groove 3.

[0078] Specifically, Wherein, h1 is the pre-step value between the top surface of the grinding area 1 and the groove area 2 before the chemical mechanical polishing process, h2 is the post-step value between the top surface of the grinding area 1 and the groove area 2 before the chemical mechanical polishing process, r is the radius of the abrasive 4 in the polishing liquid, and CD is the line width of the measured groove 3.

[0079] It should be noted that in actual production, due to the different manufacturing processes of the abrasive particles 4 in the grinding liquid, the shape of the abrasive particles 4 may be non-spherical. The abrasive particles 4 in the grinding liquid are equivalent to spheres, and their equivalent radius can be used as the radius r of the abrasive particles 4.

[0080] In this way, when the line width of the measuring groove 3 is smaller than the diameter of the abrasive 4 and the abrasive 4 cannot enter the measuring groove 3 and the bottom of the measuring groove 3, the depth of the measuring groove 3 is determined by the size of the abrasive 4 in the polishing liquid, so that the height difference between the lowest point where the abrasive 4 penetrates into the measuring groove 3 and the top surface of the grinding area 1 before and after the chemical mechanical polishing process is smaller than the depth of the measuring groove 3. In this way, the lowest point where the abrasive 4 penetrates into the measuring groove 3 cannot contact the bottom of the measuring groove 3 (i.e., the top surface of the groove area 2), thereby avoiding further grinding to the top surface of the groove area 2 by the chemical mechanical polishing process, further reducing the damage to the top surface of the groove area 2, and making the height of the top surface of the groove area 2 remain unchanged before and after the chemical mechanical polishing process, thereby further improving the measurement accuracy of the step difference that needs to be measured before and after the chemical mechanical polishing process, more accurately measuring the actual grinding amount of the grinding area 1, and further improving the measurement accuracy of the grinding amount of the grinding area 1 or the chemical mechanical polishing process.

[0081] Combination Fig.11 As shown, the embodiment of the present disclosure provides a method for measuring semiconductor polishing amount, which at least includes: S1101, forming a semiconductor measurement structure on a wafer; wherein the semiconductor measurement structure at least includes a groove region 2 and a grinding region 1; a top surface of the grinding region 1 is higher than a top surface of the groove region 2, and a side wall of the grinding region 1 and a top surface of the groove region 2 are combined to form a measurement groove 3; S1102, determining the grinding amount of the grinding area 1 by measuring the step difference between the grinding area 1 and the top surface of the area before and after the chemical mechanical polishing process.

[0082] By using the semiconductor grinding amount measurement method provided by the embodiment of the present disclosure, a semiconductor measurement structure is formed on a wafer. The semiconductor measurement structure is formed by a measurement groove 3 formed by the groove area 2 and the grinding area 1. Since the top surface of the grinding area 1 is higher than the top surface of the groove area 2, the grinding area 1 and the groove area 2 are stepped through the measurement groove 3, so that the step value here can be measured by a step meter or an atomic force microscope. Before and after the chemical mechanical polishing process, the step value before and after the step between the top surface of the grinding area 1 and the groove area 2 is measured. The grinding amount of the grinding area 1 can be determined by the difference between the step value before and after the step value, and the grinding amount can be used as the measurement value of the grinding amount of the chemical mechanical polishing process. When there are micro-undulations on the bottom surface of the wafer, since the measurement is non-optical measurement, the micro-undulations on the surface of the bottom film layer of the wafer during the measurement process will not cause optical interference (such as interference such as diffuse reflection caused by surface unevenness), so there is no measurement deviation caused by optical interference, so that the measurement result is more accurate. Compared with the limitation of optical measurement that is limited by the surface uniformity of the underlying film layer and the difficulty in measuring metal materials, the measurement process of the embodiment of the present disclosure is not limited by the uniformity of the underlying film layer of the wafer, and is not limited by the film material of the semiconductor measurement structure. When there is no optical film layer information of the corresponding film layer, the semiconductor measurement structure of the embodiment of the present disclosure can still be used for measurement, so the semiconductor measurement structure of the embodiment of the present disclosure is more widely applicable. In addition, compared with the equipment cost of the optical measurement machine, the equipment cost of the equipment for measuring step difference (such as step gauge, atomic force microscope, etc.) is lower, so the embodiment of the present disclosure can reduce costs.

[0083] It should be noted that, in some embodiments, the measurement groove 3 is formed by a photolithography process and an etching process. In other embodiments, after the photolithography process and the etching process, the measurement groove 3 needs to be formed by a process such as chemical vapor deposition (CVD) or physical vapor deposition (PVD).

[0084] Optionally, before one or more chemical mechanical polishing processes in the wafer manufacturing process, one or more corresponding measuring grooves 3 are formed, and each measuring groove 3 is formed by the side wall of the corresponding grinding area 1 and the top surface of the corresponding groove area 2; by measuring the step difference corresponding to the measuring groove 3 before and after the corresponding chemical mechanical polishing process, the grinding amount of the corresponding grinding area 1 is determined.

[0085] In this way, since the previous chemical mechanical polishing process may affect the morphology of the measuring groove 3 (such as affecting the depth of the measuring groove 3), before each chemical mechanical polishing process, it is necessary to ensure that the measuring groove 3 corresponding to the process is formed. The measuring groove 3 corresponding to the chemical mechanical polishing process only measures the grinding amount of the grinding area 1 before and after the corresponding chemical mechanical polishing process, which is conducive to improving the measurement accuracy of the grinding amount of the grinding area 1 in each chemical mechanical polishing process. In addition, one or more measuring grooves 3 can be set for each chemical mechanical polishing process, so the number of measuring grooves 3 can be flexibly set to improve design flexibility.

[0086] Specifically, the formation process parameters of the corresponding measuring groove 3 are controlled by the desired size of the abrasive grains 4 corresponding to each chemical mechanical polishing process. More specifically, the formation process parameters at least include: the line width corresponding to the line width of the measuring groove 3 in the mask of the photolithography process, the etching depth corresponding to the depth of the measuring groove 3 in the etching process, and the etching line width corresponding to the line width of the measuring groove 3 in the etching process.

[0087] It should be noted that “the line width corresponding to the line width of the measurement groove 3 in the mask of the photolithography process”, “the etching depth corresponding to the depth of the measurement groove 3 in the etching process”, and “the etching line width corresponding to the line width of the measurement groove 3 in the etching process” are only exemplary expressions. The actual process parameters for forming the measurement groove 3 include but are not limited to the above three types. The formation process parameters can be adjusted and set according to actual needs and will not be repeated here.

[0088] In this way, by controlling the desired size of the corresponding abrasive grains 4 in each chemical mechanical polishing process, the formation process parameters of the corresponding measuring groove 3 are controlled, so that the line width and depth of the measuring groove 3 meet the aforementioned conditions, and the corresponding abrasive grains 4 are prevented from entering the measuring groove 3, and the lowest point of the corresponding abrasive grains 4 is prevented from contacting the bottom of the measuring groove 3, so as to reduce the damage of the abrasive grains 4 to the top surface of the groove area 2 during each chemical mechanical polishing process, thereby further improving the measurement accuracy.

[0089] There are multiple pre-processes before the chemical mechanical polishing process, which are preliminarily divided into a first pre-process and a second pre-process according to the influence on the size and morphology of the measuring groove 3. The first pre-process refers to a process that will affect the morphology of the measuring groove 3 and make the size of the measuring groove 3 deviate from the expected process. The second pre-process refers to a pre-process that will not affect the morphology of the measuring groove 3, and the measuring groove 3 can be directly formed during this process.

[0090] In some embodiments, the first pre-process is, for example, a film deposition process to form a device after forming the measurement trench 3, which may reduce the line width and depth of the measurement trench 3. The second pre-process is, for example, a photolithography and etching process for directly forming the measurement trench 3.

[0091] Optionally, forming the measuring groove 3 at least includes: a first preceding process is further included before the chemical mechanical polishing process; before the first preceding process, determining that the preset size of the initial groove is a first size, and the first size is the same as the preset size of the measuring groove 3; adjusting the preset size of the initial groove to a second size by a preset change amount of the preset size of the initial groove through the first preceding process, so that the vector sum of the second size and the preset change amount is equal to the first size; forming the initial groove according to the second size; executing the first preceding process to change the actual size of the initial groove from the second size to the first size, thereby forming the measuring groove 3.

[0092] In this way, combined Fig.12 As shown, before the chemical mechanical polishing process, if the measuring groove 3 is formed first and then the first pre-process affecting the groove shape is performed, the size of the measuring groove 3 will be affected. For example, the film deposition makes the morphology of the measuring groove 3 narrower and shallower (refer to Fig.12 (a) Changed to Fig.12 (b), that is, h0 becomes h3, CD0 becomes CD3), resulting in the actual size of the measuring groove 3 not meeting the design expectations. Therefore, when designing the measuring groove 3, it is necessary to correct its depth or line width. For example, the correction of the line width of the measuring groove 3 can correct the size corresponding to the line width of the measuring groove on the mask, and the correction of the depth of the measuring groove 3 can correct the etching depth corresponding to the groove in the etching process. Before forming the measuring groove 3, when designing the preset size of the measuring groove 3, first design an initial groove size that is the same as the preset size of the measuring groove 3 (that is, the first size that meets the design expectations, reference Fig.12 (a) h0 and CD0), and then simulate and calculate the impact of the first pre-process on the initial trench morphology (for example, from Fig.12 (a) Changed to Fig.12(b) process, preset the change amount △h and △CD, △h = h3-h0, △CD = CD3-CD0, so that the initial groove morphology becomes narrower and shallower). At this time, the initial groove morphology needs to be designed to be wider and deeper (that is, it needs to be designed as the second size, refer to Fig.12 (c) h4 and CD4, it is obvious that the second size is not the first size that meets the design expectation of the measured groove 3) to offset the influence of the first pre-process on the initial groove morphology. The size of the changed initial groove is the second size, so that the initial groove of the second size is affected by the first pre-process on the morphology of the initial groove (for example, from Fig.12 (c) Changed to Fig.12 (d), i.e. h4+△h=h0, CD4+△CD=CD0), to restore the preset size of the measuring groove 3 (i.e. the first size that meets the design expectation, refer to Fig.12 After the design is completed, first form the second dimension as shown in Fig.12 (c) shows the initial groove, which is wider and deeper than the desired measurement groove 3. At this time, the first pre-process is performed again, so that the initial groove of the second size is restored to the desired size (i.e., the first size) of the measurement groove 3 after the first pre-process changes the morphology of the initial groove (i.e., the vector sum of the preset change amount). After the first pre-process is completed, the following is formed: Fig.12 (d) shows a measurement groove 3, the actual size of the measurement groove 3 formed is consistent with the preset size during design. In this way, the measurement groove 3 can be formed together with the core functional area, that is, it can be designed together on the mask of the core functional area first, and the initial groove is formed by etching in the core functional area, for example, before the mechanical polishing process is performed, the first pre-process that can change the initial groove morphology is performed for the purpose of forming the core functional area to form the measurement groove 3. Since the formation of the measurement groove 3 does not require a separate mask, the formation process of the measurement groove 3 can be simplified, the production efficiency can be improved, and the production cost can be reduced.

[0093] It should be noted that the “first size” and “second size” are merely exemplary expressions, and the preset sizes of the initial groove include but are not limited to the above two sizes. The preset sizes can be adjusted according to actual needs and will not be described in detail here.

[0094] Optionally, forming the measuring groove 3 at least includes: a second pre-process before the chemical mechanical polishing process; and directly forming the measuring groove 3 in the second pre-process according to a preset size of the measuring groove 3 .

[0095] In this way, the measuring groove 3 can be directly formed in the second preceding process before the chemical mechanical polishing process. Since the measuring groove 3 is directly processed by the chemical mechanical polishing process after being formed, the morphology and size of the measuring groove 3 will not change, thereby improving the measurement accuracy of the grinding amount of the grinding area 1 in the chemical mechanical polishing process. In addition, the measuring groove 3 can be designed separately without having to be designed together on the photomask for forming the device. If the process flow or process parameters are changed during the process of forming the device, the final shape of the measuring groove 3 will not be changed. This is conducive to improving the setting flexibility of the process of forming the measuring groove 3.

[0096] It should be noted that the “first preliminary process” and “second preliminary process” are merely exemplary expressions. The preliminary process of the chemical mechanical polishing process includes but is not limited to the above two processes. The preliminary process can be adjusted and set according to actual needs and will not be described in detail here.

[0097] By using the semiconductor measurement structure and the semiconductor grinding amount measurement method provided by the embodiment of the present disclosure, a semiconductor measurement structure is formed on a wafer. The semiconductor measurement structure is formed by a measurement groove 3 formed by the groove area 2 and the grinding area 1. Since the top surface of the grinding area 1 is higher than the top surface of the groove area 2, the grinding area 1 and the groove area 2 are stepped through the measurement groove 3, so that the step value here can be measured by a step meter or an atomic force microscope. Before and after the chemical mechanical polishing process, the step value before and after the step between the top surface of the grinding area 1 and the groove area 2 is measured. The grinding amount of the grinding area 1 can be determined by the difference between the step value before and after the step value, and the grinding amount can be used as the measurement value of the grinding amount of the chemical mechanical polishing process. When there are micro-undulations on the bottom surface of the wafer, since the measurement is non-optical measurement, the micro-undulations on the surface of the bottom film layer of the wafer during the measurement process will not cause optical interference (such as interference such as diffuse reflection caused by surface unevenness), so there is no measurement deviation caused by optical interference, so that the measurement result is more accurate. Compared with the limitation of optical measurement that is limited by the surface uniformity of the underlying film layer and the difficulty in measuring metal materials, the measurement process of the embodiment of the present disclosure is not limited by the uniformity of the underlying film layer of the wafer, and is not limited by the film material of the semiconductor measurement structure. When there is no optical film layer information of the corresponding film layer, the semiconductor measurement structure of the embodiment of the present disclosure can still be used for measurement, so the semiconductor measurement structure of the embodiment of the present disclosure is more widely applicable. In addition, compared with the equipment cost of the optical measurement machine, the equipment cost of the equipment for measuring step difference (such as step gauge, atomic force microscope, etc.) is lower, so the embodiment of the present disclosure can reduce costs.

[0098] The above description and the accompanying drawings fully illustrate the embodiments of the present disclosure so that those skilled in the art can practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The embodiments of the present disclosure are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof.

Claims

1. A semiconductor measurement structure, characterized in that: The semiconductor measurement structure is disposed on the wafer, and the semiconductor measurement structure at least includes a groove area and a grinding area; wherein the top surface of the grinding area is higher than the top surface of the groove area, and the sidewall of the grinding area and the top surface of the groove area are combined to form a measuring groove; The polishing amount of the polishing area is determined by measuring the step difference between the polishing area and the top surface of the groove area before and after the chemical mechanical polishing process.

2. The semiconductor measurement structure according to claim 1, characterized in that: The step difference measuring instrument at least includes: a step profiler or an atomic force microscope.

3. The semiconductor measurement structure according to claim 1, wherein: The grinding area is configured as a film layer structure, and the film layer types of the grinding area include a single type or multiple types.

4. The semiconductor measurement structure according to any one of claims 1 to 3, characterized in that: The number of the semiconductor measurement structures is set to be one or more.

5. The semiconductor measurement structure according to any one of claims 1 to 3, characterized in that: The size of the measuring groove is determined by the size of the abrasive particles in the polishing liquid, so that the line width of the measuring groove is smaller than the diameter of the abrasive particles.

6. The semiconductor measurement structure according to claim 5, characterized in that: The depth of the measuring groove is determined by the size of the abrasive particles in the polishing liquid and the line width of the measuring groove, so that the height difference between the lowest point where the abrasive particles penetrate into the measuring groove and the top surface of the polishing area before and after the chemical mechanical polishing process is less than the depth of the measuring groove.

7. A method for measuring semiconductor polishing amount, characterized in that: At least: Forming a semiconductor measurement structure on a wafer; wherein the semiconductor measurement structure at least includes a groove area and a grinding area; the top surface of the grinding area is higher than the top surface of the groove area, and the sidewall of the grinding area and the top surface of the groove area are surrounded by a measurement groove; The grinding amount of the grinding area is determined by measuring the step difference between the grinding area and the top surface of the area before and after the chemical mechanical polishing process.

8. The measuring method according to claim 7, characterized in that: At least: Before one or more chemical mechanical polishing processes in the wafer manufacturing process, one or more corresponding measurement grooves are formed, each of which is formed by enclosing the corresponding grinding area sidewall and the corresponding groove area top surface; The grinding amount of the corresponding grinding area is determined by measuring the step difference corresponding to the measuring groove before and after grinding in the corresponding chemical mechanical polishing process.

9. The measuring method according to claim 7, characterized in that: Forming a measurement groove includes at least: A first pre-process is also included before the chemical mechanical polishing process; Before the first pre-sequence process, determining a preset size of the initial groove as a first size, the first size being the same as a preset size of the measuring groove; By performing a preset change amount on the preset size of the initial groove by the first preceding process, the preset size of the initial groove is adjusted to a second size, so that a vector sum of the second size and the preset change amount is equal to the first size; forming an initial groove according to a second size; The first pre-process is performed to change the actual size of the initial trench from the second size to the first size, thereby forming a measurement trench.

10. The measuring method according to claim 7, characterized in that: Forming a measurement groove includes at least: A second pre-process is also included before the chemical mechanical polishing process; According to the preset size of the measurement trench, the measurement trench is directly formed in the second preceding process.

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