Measurement method of semiconductor structure

Abstract

The invention relates to a method for measuring a semiconductor structure. The semiconductor structure comprises a substrate, a first contact plug and a second contact plug; an active region and a first isolation structure at least located in the substrate are arranged in the substrate, and the top surface of the first isolation structure is higher than the top surface of the substrate; the first contact plug is located right above the first isolation structure, the second contact plug is located right above the active region, and the top surface of the first contact plug is flush with the top surface of the second contact plug; the square semiconductor structure measurement method comprises the steps of obtaining a first resistance value of a first contact plug; acquiring a second resistance value of the second contact plug; and determining the height difference between the top surface of the first isolation structure and the top surface of the active region according to the first resistance value and the second resistance value. The device can directly measure the height difference, enlarges the representation range, is convenient and rapid, can reduce the manual error of slice measurement by different operators, can selectively measure the height difference of different positions, and facilitates the process debugging and selection.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor manufacturing, and in particular to a method for measuring a semiconductor structure. Background Art

[0002] In the field of semiconductor manufacturing technology, the height difference between different structures in the semiconductor structure usually affects the performance of the semiconductor device. In process characterization, appropriate measurement technology is needed to ensure that the height difference between the structures is kept within a controlled range, thereby ensuring the high quality of the product.

[0003] In particular, the height difference between the active area and the isolation structure in the semiconductor structure. A large height difference between the two may lead to stress concentration and increase the risk of failure of the semiconductor device during use. In traditional processes, a transmission electron microscope (TEM) is usually used to slice the semiconductor structure and then measure the height difference between the two. However, the microscope has limited slicing points, and the error when different operators perform measurements is also large.

[0004] Therefore, how to conveniently and accurately measure the height difference between structures has become an urgent problem to be solved. Summary of the invention

[0005] Based on this, an embodiment of the present application provides a method for measuring a semiconductor structure.

[0006] According to some embodiments, the present application provides a method for measuring a semiconductor structure, the semiconductor structure comprising a substrate, a first contact plug and a second contact plug; the substrate has an active region and at least a first isolation structure located in the substrate, the top surface of the first isolation structure is higher than the top surface of the substrate; the first contact plug is located directly above the first isolation structure, the second contact plug is located directly above the active region, and the top surfaces of the first contact plug and the second contact plug are flush; the method comprises:

[0007] obtaining a first resistance value of a first contact plug;

[0008] obtaining a second resistance value of the second contact plug;

[0009] A height difference between a top surface of the first isolation structure and a top surface of the active region is determined according to the first resistance value and the second resistance value.

[0010] In the semiconductor structure measurement method of the above embodiment, the first contact plug is located directly above the first isolation structure, the second contact plug is located directly above the active area, and the top surfaces of the first contact plug and the second contact plug are flush. By obtaining the first resistance value of the first contact plug and the second resistance value of the second contact plug, the height difference between the top surface of the first isolation structure and the top surface of the active area can be determined based on the first resistance value and the second resistance value. Compared with the method of slicing the semiconductor structure to measure the height difference using a microscope, slicing is not required, and the height difference between all related structures in the semiconductor device can be directly measured, thereby increasing the characterization range, being convenient and quick, and being able to reduce the manual errors of slicing measurements by different operators. At the same time, the height difference at different positions can be selectively measured according to the requirements of different devices, facilitating process debugging and selection.

[0011] In some embodiments, determining a height difference between a top surface of the first isolation structure and a top surface of the active region according to the first resistance value and the second resistance value includes:

[0012] Determining a height difference between the first contact plug and the second contact plug according to the first resistance value and the second resistance value;

[0013] The height difference between the top surface of the first isolation structure and the top surface of the active region is determined according to the height difference between the first contact plug and the second contact plug.

[0014] In some embodiments, the height difference between the top surface of the first isolation structure and the top surface of the active region is determined according to the height difference between the first contact plug and the second contact plug, including: the height difference between the first contact plug and the second contact plug is equal to the height difference between the top surface of the first isolation structure and the top surface of the active region.

[0015] In some embodiments, the first contact plug and the second contact plug are made of the same material; the height difference between the first contact plug and the second contact plug is determined according to the first resistance value and the second resistance value, including: according to the first resistance value R1 and the second resistance value R2, the height difference H1 between the first contact plug and the second contact plug is determined to be 1 / k*(R1-R2); wherein k is the resistivity of the first contact plug and the second contact plug.

[0016] In some embodiments, the semiconductor structure also includes a dielectric layer located on the substrate, the dielectric layer has a boss structure, and the boss structure is located directly below the first isolation structure; the method also includes: determining the height of the boss structure based on the height difference between the top surface of the first isolation structure and the top surface of the active area.

[0017] In some embodiments, determining the height of the platform structure according to the height difference between the top surface of the first isolation structure and the top surface of the active region includes: determining the height of the platform structure according to the height difference between the top surface of the first isolation structure and the top surface of the active region.

[0018] In some embodiments, determining the height difference between the top surface of the first isolation structure and the top surface of the active area according to the first resistance value and the second resistance value includes: determining the height difference between the top surface of the first isolation structure and the top surface of the active area, and the height of the boss structure according to the first resistance value and the second resistance value.

[0019] In some embodiments, the substrate further includes a second isolation structure, the top surface of the second isolation structure is lower than the top surface of the substrate; the semiconductor structure further includes a third contact plug, the third contact plug is located directly above the second isolation structure, and the top surface of the third contact plug is flush with the top surface of the first contact plug; the method further includes:

[0020] obtaining a third resistance value of the third contact plug;

[0021] A height difference between a top surface of the second isolation structure and a top surface of the active region is determined according to the first resistance value and the third resistance value.

[0022] In some embodiments, determining a height difference between a top surface of the second isolation structure and a top surface of the first isolation structure according to the first resistance value and the third resistance value includes:

[0023] Determining a height difference between the first contact plug and the third contact plug according to the first resistance value and the third resistance value;

[0024] The height difference between the top surface of the second isolation structure and the top surface of the first isolation structure is determined according to the height difference between the first contact plug and the third contact plug.

[0025] In some embodiments, the semiconductor structure further includes a bit line structure extending along a first direction and a word line structure extending along a second direction; the first contact plug is located above the overlapping area of ​​the bit line structure and the word line structure, and the second contact plug is located above the bit line structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of a flow chart of a semiconductor structure measurement method provided in one embodiment of the present application;

[0027] Figure 2 A schematic diagram of a cross-sectional view of a semiconductor structure in a semiconductor structure measurement method provided in an embodiment of the present application;

[0028] Figure 3 A schematic top view of a semiconductor structure in a semiconductor structure measurement method provided in one embodiment of the present application.

[0029] Explanation of the reference numerals: 10, substrate; 11, active region; 12, first isolation structure; 13, second isolation structure; 21, first contact plug; 22, second contact plug; 23, third contact plug; 30, dielectric layer; 40, bit line structure; 50, word line structure. DETAILED DESCRIPTION

[0030] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Preferred embodiments of the present invention are provided in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0032] In the case of using “including”, “having”, and “comprising” described herein, another component may be added unless a clear limiting term such as “only”, “consisting of”, etc. is used. Unless mentioned otherwise, a term in the singular form may include a plural form and should not be understood as being one in number.

[0033] In addition, in order to clearly indicate the multiple layers and regions in the drawings, the thickness of each layer and each region in the drawings are enlarged to clearly illustrate the relative positions between the layers and the distribution of each region. When a layer, film, region, plate, etc. is expressed as being located on the "side" of another part, the expression includes not only the case where it is "directly" above the other part, but also the case where there are other layers in between. And, it is understood that when a layer, film, region, plate, etc. is expressed as being located on the "side" of another part, it generally refers to the side located directly above the other part.

[0034] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers, doping types and / or parts, these elements, components, regions, layers, doping types and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, doping type or part from another element, component, region, layer, doping type or part. Therefore, without departing from the teachings of the present disclosure, the first element, component, region, layer, doping type or part discussed below can be represented as a second element, component, region, layer or part.

[0035] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientations shown in the figures, spatially relative terms also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, an element or feature described as "under other elements" or "under it" or "under it" will be oriented as being "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include additional orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0036] Embodiments of the invention are described herein with reference to cross-sectional views that are schematic representations of idealized embodiments (and intermediate structures) of the present disclosure, such that variations in the shapes shown due to, for example, manufacturing techniques and / or tolerances are anticipated. Thus, embodiments of the present disclosure should not be limited to the specific shapes of the regions shown herein, but rather include deviations in shapes due to, for example, manufacturing techniques. Thus, the regions shown in the figures are schematic in nature, their shapes do not represent the actual shapes of the regions of the device, and do not limit the scope of the present disclosure.

[0037] Based on this, an embodiment of the present application provides a method for measuring a semiconductor structure.

[0038] See also Figure 1According to some embodiments, the present application provides a method for testing a semiconductor structure. The semiconductor structure includes a substrate, a first contact plug, and a second contact plug; the substrate has an active region and at least a first isolation structure located in the substrate, and the top surface of the first isolation structure is higher than the top surface of the substrate; the first contact plug is located directly above the first isolation structure, and the second contact plug is located directly above the active region, and the top surfaces of the first contact plug and the second contact plug are flush. The method for testing a semiconductor structure includes the following steps.

[0039] Step S10, obtaining a first resistance value of a first contact plug;

[0040] Step S20, obtaining a second resistance value of the second contact plug;

[0041] Step S30: determining a height difference between a top surface of the first isolation structure and a top surface of the active region according to the first resistance value and the second resistance value.

[0042] In the semiconductor structure measurement method of the above embodiment, the first contact plug is located directly above the first isolation structure, the second contact plug is located directly above the active area, and the top surfaces of the first contact plug and the second contact plug are flush. By obtaining the first resistance value of the first contact plug and the second resistance value of the second contact plug, the height difference between the top surface of the first isolation structure and the top surface of the active area can be determined based on the first resistance value and the second resistance value. Compared with the method of slicing the semiconductor structure to measure the height difference using a microscope, slicing is not required, and the height difference between all related structures in the semiconductor device can be directly measured, thereby increasing the characterization range, being convenient and quick, and being able to reduce the manual errors of slicing measurements by different operators. At the same time, the height difference at different positions can be selectively measured according to the requirements of different devices, facilitating process debugging and selection.

[0043] In some embodiments, step S30, determining a height difference between a top surface of the first isolation structure and a top surface of the active region according to the first resistance value and the second resistance value, includes:

[0044] Step S31, determining a height difference between the first contact plug and the second contact plug according to the first resistance value and the second resistance value;

[0045] Step S32 , determining a height difference between a top surface of the first isolation structure and a top surface of the active region according to a height difference between the first contact plug and the second contact plug.

[0046] In some embodiments, step S32, determining a height difference between a top surface of the first isolation structure and a top surface of the active region according to a height difference between the first contact plug and the second contact plug, includes:

[0047] Step S321 : A height difference between the first contact plug and the second contact plug is equal to a height difference between a top surface of the first isolation structure and a top surface of the active region.

[0048] In some embodiments, the first contact plug and the second contact plug are made of the same material.

[0049] In some embodiments, step S31, determining a height difference between the first contact plug and the second contact plug according to the first resistance value and the second resistance value, includes:

[0050] Step S311 , determining a height difference H1=1 / k*(R1-R2) between the first contact plug and the second contact plug according to the first resistance value R1 and the second resistance value R2 ; wherein k is the resistivity of the first contact plug and the second contact plug.

[0051] In some embodiments, the semiconductor structure further includes a dielectric layer located on the substrate, the dielectric layer has a boss structure, and the boss structure is located directly below the first isolation structure.

[0052] In some embodiments, the method further comprises:

[0053] Step S40 , determining the height of the boss structure according to the height difference between the top surface of the first isolation structure and the top surface of the active region.

[0054] In some embodiments, step S40, determining the height of the boss structure according to the height difference between the top surface of the first isolation structure and the top surface of the active region, includes:

[0055] Step S41 : The height difference between the top surface of the first isolation structure and the top surface of the active region is equal to the height of the boss structure.

[0056] In some embodiments, step S41, determining a height difference between a top surface of the first isolation structure and a top surface of the active region according to the first resistance value and the second resistance value, includes:

[0057] Step S411 , determining a height difference between a top surface of the first isolation structure and a top surface of the active region, and a height of the boss structure according to the first resistance value and the second resistance value.

[0058] In some embodiments, the substrate further includes a second isolation structure, the top surface of the second isolation structure is lower than the top surface of the substrate; the semiconductor structure also includes a third contact plug, the third contact plug is located directly above the second isolation structure, and the top surface of the third contact plug is flush with the top surface of the first contact plug.

[0059] In some embodiments, the method further comprises:

[0060] Step S50, obtaining a third resistance value of the third contact plug;

[0061] Step S51 : determining a height difference between a top surface of the second isolation structure and a top surface of the active region according to the first resistance value and the third resistance value.

[0062] In some embodiments, step S51, determining a height difference between a top surface of the second isolation structure and a top surface of the first isolation structure according to the first resistance value and the third resistance value, includes:

[0063] Step S511, determining a height difference between the first contact plug and the third contact plug according to the first resistance value and the third resistance value;

[0064] Step S512: determining a height difference between a top surface of the second isolation structure and a top surface of the first isolation structure according to a height difference between the first contact plug and the third contact plug.

[0065] In some embodiments, the semiconductor structure further includes a bit line structure extending along a first direction and a word line structure extending along a second direction; the first contact plug is located above the overlapping area of ​​the bit line structure and the word line structure, and the second contact plug is located above the bit line structure.

[0066] In the above embodiments of the present disclosure, unless otherwise specified herein, the execution of each step in the method is not strictly limited in order, and these steps may not necessarily be executed in the order described, and may be executed in other ways. Moreover, at least a part of any step may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but may be executed at different times, and the execution order of these sub-steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0067] In order to more clearly illustrate the method for preparing the semiconductor structure provided by the above embodiment, Figures 1 to 3 The method is described in detail.

[0068] like Figure 2 As shown, in some embodiments, the semiconductor structure includes a substrate 10, a first contact plug 21 and a second contact plug 22; the substrate 10 has an active area 11 and at least a first isolation structure 12 located in the substrate 10, and the top surface of the first isolation structure 12 is higher than the top surface of the substrate 10; the first contact plug 21 is located directly above the first isolation structure 12, and the second contact plug 22 is located directly above the active area 11, and the top surfaces of the first contact plug 21 and the second contact plug 22 are flush.

[0069] For example, the substrate 10 can be made of semiconductor material, insulating material, conductor material or any combination of their material types. The substrate 10 can be a single-layer structure or a multi-layer structure. For example, the substrate 10 can be a silicon (Si) substrate 10, a silicon germanium (SiGe) substrate 10, a silicon germanium carbon (SiGeC) substrate 10, a silicon carbide (SiC) substrate 10, a gallium arsenide (GaAs) substrate 10, an indium arsenide (InAs) substrate 10, an indium phosphide (InP) substrate 10 or other III / V semiconductor substrates 10 or II / VI semiconductor substrates 10. Alternatively, for example, the substrate 10 can be a layered substrate 10 including a stack of Si and SiGe, a stack of Si and SiC, a silicon on insulator (SOI) or a silicon germanium on insulator, etc.

[0070] For example, the first isolation structure 12 can adopt a shallow trench isolation structure (STI) to isolate two adjacent devices and prevent failure due to the flow of current between adjacent devices. The shallow trench isolation structure can reduce the area occupied by the wafer surface, increase the integration of the device, maintain the flatness of the wafer surface, and reduce the risk of channel width erosion.

[0071] Combination Figure 1 and Figure 2 It is understood that in step S10 , a first resistance value of the first contact plug 21 is obtained.

[0072] For example, a four-probe measurement method or a micro-current measurement method may be used to measure the first resistance value of the first contact plug 21 to obtain the first resistance value of the first contact plug 21. The basic principle of the four-probe measurement method is to contact the sample with four probes at the same time to improve measurement accuracy and eliminate the influence of contact resistance.

[0073] Combination Figure 1 and Figure 2 It is understood that in step S20 , the second resistance value of the second contact plug 22 is obtained.

[0074] Accordingly, the second resistance value of the second contact plug 22 may also be measured by a four-probe measurement method or a micro-current measurement method to obtain the second resistance value of the second contact plug 22.

[0075] Combination Figure 1 and Figure 2 It is understood that in step S30 , determining the height difference between the top surface of the first isolation structure 12 and the top surface of the active region 11 according to the first resistance value and the second resistance value may include the following steps S31 and S32 .

[0076] Step S31, determining a height difference H1 between the first contact plug 21 and the second contact plug 22 according to the first resistance value and the second resistance value;

[0077] Step S32 , determining a height difference H0 between a top surface of the first isolation structure 12 and a top surface of the active region 11 according to a height difference H1 between the first contact plug 21 and the second contact plug 22 .

[0078] In some embodiments, step S32, determining a height difference between a top surface of the first isolation structure 12 and a top surface of the active region 11 according to a height difference between the first contact plug 21 and the second contact plug 22, includes:

[0079] Step S321 : A height difference H1 between the first contact plug 21 and the second contact plug 22 is equal to a height difference H0 between a top surface of the first isolation structure 12 and a top surface of the active region 11 .

[0080] In some embodiments, the first contact plug and the second contact plug 22 are made of the same material.

[0081] In some embodiments, step S31, determining a height difference between the first contact plug 21 and the second contact plug 22 according to the first resistance value and the second resistance value, includes:

[0082] Step S311 , determining a height difference H1=1 / k*(R1−R2) between the first contact plug 21 and the second contact plug 22 according to the first resistance value R1 and the second resistance value R2 ; wherein k is the resistivity of the first contact plug and the second contact plug 22 .

[0083] like Figure 2 As shown, in some embodiments, the first contact plug 21 and the second contact plug 22 are both cylindrical or truncated cone-shaped, the height of the first contact plug 21 is L1, and the height of the second contact plug 22 is L2. It can be understood that the cylinder resistance can be derived by the following formula: R = ρ / (πr 2 )*L, where r is the radius of the cylindrical first contact plug 21 or the cylindrical second contact plug 22, and ρ is the resistivity of the first contact plug 21 or the second contact plug 22. The first resistance value R1 of the cylindrical first contact plug 21 can be represented by R1=ρ / (πr 2 )*L1, the second resistance value R2 of the cylindrical second contact plug 22 can be represented by R2=ρ / (πr 2)*L2; accordingly, the truncated cone resistance can be derived by the following formula: R=ρ / (πr1r2)*L, wherein r1 is the top surface radius of the cylindrical first contact plug 21 or the cylindrical second contact plug 22, r2 is the bottom surface radius of the cylindrical first contact plug 21 or the cylindrical second contact plug 22, and ρ is the resistivity of the first contact plug 21 or the second contact plug 22. Then, the first resistance value R1 of the truncated cone first contact plug 21 can be characterized as R1=ρ / (πr1r2)*L1, and the second resistance value R2 of the truncated cone second contact plug 22 can be characterized as R2=ρ / (πr1r2)*L2.

[0084] According to the above formula, the first resistance value R1 of the first contact plug 21 and the second resistance value R2 of the second contact plug 22 are both proportional to k*L. Therefore, when calculating the height difference H1 between the first contact plug 21 and the second contact plug 22, H1=L1-L2=1 / k*(R1-R2), thereby achieving the determination of the height difference H1 between the first contact plug 21 and the second contact plug 22 according to the first resistance value R1 and the second resistance value R2.

[0085] like Figure 2 As shown, in some embodiments, the semiconductor structure further includes a dielectric layer 30 located on the substrate 10 . The dielectric layer 30 has a boss structure 301 . The boss structure 301 is located directly below the first isolation structure 12 .

[0086] In some embodiments, the method further comprises:

[0087] Step S40 , determining a height H2 of the boss structure 301 according to a height difference H1 between a top surface of the first isolation structure 12 and a top surface of the active region 11 .

[0088] In some embodiments, step S40, determining the height of the boss structure 301 according to the height difference between the top surface of the first isolation structure 12 and the top surface of the active region 11, includes:

[0089] Step S41 : A height difference H1 between the top surface of the first isolation structure 12 and the top surface of the active region 11 is equal to a height H2 of the boss structure 301 .

[0090] In some embodiments, step S41, determining a height difference between a top surface of the first isolation structure 12 and a top surface of the active region 11 according to the first resistance value and the second resistance value, includes:

[0091] Step S411 , determining the height difference H1=1 / k*(R1-R2) between the top surface of the first isolation structure 12 and the top surface of the active region 11 and the height H2=H1=1 / k*(R1-R2) of the boss structure 301 according to the first resistance value R1 and the second resistance value R2.

[0092] like Figure 2 As shown, in some embodiments, the substrate 10 further has a second isolation structure 13, and the top surface of the second isolation structure 13 is lower than the top surface of the substrate 10; the semiconductor structure also includes a third contact plug 23, and the third contact plug 23 is located directly above the second isolation structure 13, and the top surface of the third contact plug 23 is flush with the top surface of the first contact plug 21.

[0093] By way of example, the third contact plugs 23 are all cylindrical or truncated cone shaped.

[0094] In some embodiments, the method further includes the following steps S50 and S51.

[0095] Step S50 , obtaining a third resistance value R3 of the third contact plug 23 .

[0096] Step S51 , determining a height difference H3 between a top surface of the second isolation structure 13 and a top surface of the active region 11 according to the first resistance value R1 and the third resistance value R3 .

[0097] In some embodiments, step S51, determining a height difference between a top surface of the second isolation structure 13 and a top surface of the first isolation structure 12 according to the first resistance value and the third resistance value, includes:

[0098] Step S511, determining a height difference between the first contact plug 21 and the third contact plug 23 according to the first resistance value R1 and the third resistance value R3;

[0099] Step S512 , determining a height difference H3=1 / k*(R3−R1) between the top surface of the second isolation structure 13 and the top surface of the first isolation structure 12 according to the height difference between the first contact plug 21 and the third contact plug 23 .

[0100] It should be noted that the principle and derivation process of determining the height difference between the first contact plug 21 and the third contact plug 23 according to the first resistance value R1 and the third resistance value R3 in step S51 are the same as those in step S31 and will not be repeated here.

[0101] like Figure 3 As shown, in some embodiments, the semiconductor structure also includes a bit line structure 40 extending along a first direction and a word line structure 50 extending along a second direction; the first contact plug 21 is located above the overlapping area of ​​the bit line structure 40 and the word line structure 50, and the second contact plug 22 is located above the bit line structure 40.

[0102] It should be noted that the first direction is perpendicular to the second direction, and the first direction can be Figure 3 The X direction shown, the second direction can be Figure 3 The Z direction is shown.

[0103] By way of example, the constituent materials of the word line structure 50 include, but are not limited to, one or more of conductive polysilicon, metal, conductive metal nitride, conductive metal oxide and metal silicide. By way of example, the metal may be tungsten (W), nickel (Ni), copper (Cu), aluminum (Al), molybdenum (Mo), ruthenium (Ru), tantalum (Ta) or titanium (Ti); the conductive metal nitride includes titanium nitride (TiN); the conductive metal oxide includes iridium oxide (IrO2); and the metal silicide includes tungsten silicon (WSi).

[0104] For example, the constituent material of the bit line structure 40 may include titanium, tungsten, tantalum, molybdenum, cobalt, platinum, titanium tungsten, tungsten nitride, titanium nitride, titanium nitride silicon or a combination thereof. For example, ruthenium, tungsten, gold or silver are all low-resistance metals, which can further reduce the resistance of the bit line material layer 113, which is beneficial to improving the test accuracy of the measurement method of the semiconductor structure.

[0105] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0106] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for measuring a semiconductor structure, characterized in that: The semiconductor structure includes a substrate, a first contact plug and a second contact plug; the substrate has an active region and at least a first isolation structure located in the substrate, and the top surface of the first isolation structure is higher than the top surface of the substrate; The first contact plug is located directly above the first isolation structure, the second contact plug is located directly above the active region, and the top surfaces of the first contact plug and the second contact plug are flush; the method comprises: obtaining a first resistance value of the first contact plug; obtaining a second resistance value of the second contact plug; A height difference between a top surface of the first isolation structure and a top surface of the active region is determined according to the first resistance value and the second resistance value.

2. The semiconductor structure measuring method according to claim 1, characterized in that: Determining a height difference between a top surface of the first isolation structure and a top surface of the active region according to the first resistance value and the second resistance value includes: determining a height difference between the first contact plug and the second contact plug according to the first resistance value and the second resistance value; A height difference between a top surface of the first isolation structure and a top surface of the active region is determined according to a height difference between the first contact plug and the second contact plug.

3. The semiconductor structure measuring method according to claim 2, characterized in that: Determining a height difference between a top surface of the first isolation structure and a top surface of the active region according to a height difference between the first contact plug and the second contact plug includes: A height difference between the first contact plug and the second contact plug is equal to a height difference between a top surface of the first isolation structure and a top surface of the active region.

4. The semiconductor structure measuring method according to claim 2, characterized in that: The first contact plug and the second contact plug are made of the same material; and according to the first resistance value and the second resistance value, determining a height difference between the first contact plug and the second contact plug comprises: According to the first resistance value R1 and the second resistance value R2, a height difference H1=1 / k*(R1-R2) between the first contact plug and the second contact plug is determined; wherein k is the resistivity of the first contact plug and the second contact plug.

5. The semiconductor structure measuring method according to any one of claims 1 to 4, characterized in that: The semiconductor structure further includes a dielectric layer located on the substrate, the dielectric layer having a boss structure, and the boss structure is located directly below the first isolation structure; the method further includes: The height of the boss structure is determined according to a height difference between a top surface of the first isolation structure and a top surface of the active region.

6. The semiconductor structure measuring method according to claim 5, characterized in that: Determining the height of the boss structure according to the height difference between the top surface of the first isolation structure and the top surface of the active region includes: A height difference between a top surface of the first isolation structure and a top surface of the active region is equal to a height of the boss structure.

7. The semiconductor structure measuring method according to claim 6, characterized in that: Determining a height difference between a top surface of the first isolation structure and a top surface of the active region according to the first resistance value and the second resistance value includes: The height difference between the top surface of the first isolation structure and the top surface of the active region, and the height of the boss structure are determined according to the first resistance value and the second resistance value.

8. The semiconductor structure measuring method according to claim 5, characterized in that: The substrate further includes a second isolation structure, the top surface of the second isolation structure is lower than the top surface of the substrate; the semiconductor structure further includes a third contact plug, the third contact plug is located directly above the second isolation structure, and the top surface of the third contact plug is flush with the top surface of the first contact plug; the method further includes: obtaining a third resistance value of the third contact plug; A height difference between a top surface of the second isolation structure and a top surface of the active region is determined according to the first resistance value and the third resistance value.

9. The semiconductor structure measuring method according to claim 8, characterized in that: Determining a height difference between a top surface of the second isolation structure and a top surface of the first isolation structure according to the first resistance value and the third resistance value includes: determining a height difference between the first contact plug and the third contact plug according to the first resistance value and the third resistance value; A height difference between a top surface of the second isolation structure and a top surface of the first isolation structure is determined according to a height difference between the first contact plug and the third contact plug.

10. The semiconductor structure measuring method according to any one of claims 1 to 3, characterized in that: The semiconductor structure further includes a bit line structure extending along a first direction and a word line structure extending along a second direction; The first contact plug is located above an overlapping region between the bit line structure and the word line structure, and the second contact plug is located above the bit line structure.

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