Thin film dielectric constant measurement structure and method of measurement thereof

Abstract

The application discloses a thin film dielectric constant measurement structure and a measurement method thereof. The application sets the first and second measurement units each comprising a plurality of metal strips in series and having different line widths, measures capacitance and calculates to obtain the edge capacitance in the interlayer capacitance and the parasitic capacitance, further sets the third measurement unit comprising a plurality of metal strips in parallel, measures capacitance and calculates to obtain the in-layer coupling capacitance in the parasitic capacitance; thus, the thin film dielectric constant measurement structure provided by the embodiment can measure and exclude the parasitic capacitance interference including the edge capacitance and the in-layer coupling capacitance, obtain the thin film dielectric constant of the thin film dielectric layer under the corresponding line width by obtaining the actual capacitance, and effectively improve the precision of the capacitance and dielectric constant measurement.

Description

Technical Field

[0001] This invention relates to the field of integrated circuit technology, and in particular to a thin film dielectric constant measurement structure and method thereof. Background Technology

[0002] With the development of very large-scale integrated circuits (VLSI), the requirements for device feature size and chip wiring density are becoming increasingly stringent for high-speed, high-density, and multifunctional integrated circuits. Therefore, chip design involves increasing the number of metal layers and reducing the spacing between metal lines. However, problems such as signal RC delay and power consumption caused by resistive and capacitive coupling are becoming increasingly significant. Using low-k dielectric materials instead of silicon dioxide as the interlayer dielectric can effectively reduce interlayer parasitic capacitance and RC delay. Low-k dielectric materials will play a crucial role in future VLSI manufacturing; therefore, measuring the K-value (i.e., dielectric constant, ε) of low-k dielectric materials is particularly important.

[0003] Please see Figure 1 This is a schematic diagram illustrating the existing capacitance method for measuring the K value of low dielectric constants. Currently, the capacitance method is commonly used to measure the K value of low dielectric constants. This method utilizes a capacitor structure composed of a metal / insulator / semiconductor (such as...). Figure 1 As shown), the CV curves of low dielectric constant thin films were measured. Then, according to the relationship ε=(C 测量 The K-value of a low dielectric constant material can be calculated using the formula *d)(ε0*A). Here, ε is the dielectric constant of the material, and C... 测量 For measuring capacitance in the accumulation region, d is the film thickness of the low dielectric constant material, and ε0 = 8.854 * 10⁻⁶. -12 F / m is the vacuum dielectric constant, and A is the area of ​​the measuring electrode. However, the capacitance C measured by the capacitance method... 测量 It is very small, typically in the pf range. At this point, parasitic capacitances such as edge capacitance and in-layer coupling capacitance can no longer be ignored, i.e., C 测量 =C 实际 +C 寄生 The dielectric constant measured by the capacitance method is actually ε = ((C) 实际 +C 寄生 )*d) / (ε0*A). Therefore, the parasitic capacitance C is measured and eliminated. 寄生 Interference makes improving measurement accuracy particularly important. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a thin film dielectric constant measurement structure and method, which can measure and eliminate parasitic capacitance interference to obtain the actual capacitance, thereby improving the accuracy of capacitance and dielectric constant measurement.

[0005] To address the aforementioned problems, an embodiment of the present invention provides a thin-film dielectric constant measurement structure, comprising: a first measurement unit, a second measurement unit, and a third measurement unit formed by sequentially stacking a first metal layer, a thin-film dielectric layer, and a patterned second metal layer; the parameters of the first metal layer and the parameters of the thin-film dielectric layer are the same in the first, second, and third measurement units; the patterned second metal layer of the first measurement unit comprises: a plurality of first metal strips connected in series, all first metal strips being connected in series at one end on the same side, the plurality of first metal strips extending along a first direction and uniformly distributed along a second direction with a first gap, all first metal strips having the same line width along the second direction, which is a first line width, wherein the first direction and the second direction are both parallel to the surface of the first metal layer, and there is an angle between the first direction and the second direction; the patterned second metal layer of the second measurement unit comprises: a plurality of second metal strips connected in series, all second metal strips being connected in series at one end on the same side, the plurality of second metal strips extending along the first direction and uniformly distributed along the second direction with a second gap, all second metal strips extending along the second direction with a second gap, all second metal strips having the same line width along the second direction. The line widths are the same, which is the second line width, and the second line width is different from the first line width; the patterned second metal layer of the third measurement unit includes: multiple third metal strips connected in parallel, the multiple third metal strips connected in parallel extend along the first direction and are evenly distributed along the second direction with a third gap, and all the third metal strips have the same line width along the second direction, which is the third line width; by measuring the first measurement capacitance of the first measurement unit, the second measurement capacitance of the second measurement unit and the third measurement capacitance of the third measurement unit, the interlayer capacitance per unit area and the parasitic capacitance including the edge capacitance per unit length and the intralayer coupling capacitance are obtained, and the thin film dielectric constant of the thin film dielectric layer under the third line width is obtained according to the actual capacitance after removing the parasitic capacitance, wherein, the first measurement capacitance of the first measurement unit is the measurement capacitance of the multiple first metal strips connected in series, the second measurement capacitance of the second measurement unit is the measurement capacitance of the multiple second metal strips connected in series, and the third measurement capacitance of the third measurement unit is the measurement capacitance of the target third metal strip, and the target third metal strip is one of the multiple third metal strips connected in parallel that has third metal strips on both sides.

[0006] In some embodiments, the first metal layer is divided into a first region, a second region, and a third region; in the first region, the patterned second metal layer includes the multiple first metal strips connected in series, and the first metal layer, the thin film dielectric layer, and the patterned second metal layer in the first region constitute the first measurement unit; in the second region, the patterned second metal layer includes the multiple second metal strips connected in series, and the first metal layer, the thin film dielectric layer, and the patterned second metal layer in the second region constitute the second measurement unit; in the third region, the patterned second metal layer includes the multiple third metal strips connected in parallel, and the first metal layer, the thin film dielectric layer, and the patterned second metal layer in the third region constitute the third measurement unit.

[0007] In some embodiments, the number of the first metal strips is the same as the number of the second metal strips; the lengths of the first metal strips, the second metal strips, and the third metal strips are all the same; and the gaps between adjacent first metal strips, adjacent second metal strips, and adjacent third metal strips are all the same.

[0008] To address the aforementioned problems, an embodiment of the present invention also provides a method for measuring the dielectric constant of a thin film, characterized by comprising the following steps: providing a thin film dielectric constant measurement structure as described in the present invention; measuring and acquiring a first measuring capacitor of the first measuring unit, a second measuring capacitor of the second measuring unit, and a third measuring capacitor of the third measuring unit; based on the first measuring capacitor and the second measuring capacitor, acquiring the edge capacitance per unit length of the interlayer capacitance and parasitic capacitance per unit area; based on the third measuring capacitor and the interlayer capacitance and edge capacitance per unit area, acquiring the intralayer coupling capacitance of the parasitic capacitance under a third linewidth of the third measuring capacitor, and then acquiring the actual capacitance under the third linewidth after removing the parasitic capacitance; and acquiring the thin film dielectric constant of the thin film dielectric layer under the third linewidth based on the actual capacitance.

[0009] The above technical solution, by setting up first and second measurement units with identical structures (both including multiple metal strips connected in series) but different linewidths, obtains the edge capacitance among interlayer capacitance and parasitic capacitance through capacitance measurement and calculation. Furthermore, by setting up a third measurement unit with different structures (including multiple metal strips connected in parallel), the intralayer coupling capacitance among parasitic capacitances is obtained through capacitance measurement and calculation. Thus, using the thin film dielectric constant measurement structure provided in this embodiment, parasitic capacitance interference, including interlayer capacitance, edge capacitance, and intralayer coupling capacitance, can be measured and eliminated. By obtaining the actual capacitance, the thin film dielectric constant of the thin film dielectric layer under the corresponding linewidth is obtained, effectively improving the accuracy of capacitance and dielectric constant measurements. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of measuring the value of K for low dielectric constant using the existing capacitance method.

[0012] Figure 2 This is a schematic diagram of a thin film dielectric constant measurement structure provided in an embodiment of the present invention;

[0013] Figure 3 For along Figure 2 Cross-sectional view of line AA in the middle;

[0014] Figure 4 For along Figure 2 Cross-sectional view of the middle BB line;

[0015] Figure 5 This is a schematic diagram of the steps of a thin film dielectric constant measurement method provided in an embodiment of the present invention. Detailed Implementation

[0016] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please refer to the following: Figures 2-4 ,in, Figure 2 This is a schematic diagram of a thin film dielectric constant measurement structure provided in an embodiment of the present invention. Figure 3 For along Figure 2 Cross-sectional view of line AA in the middle. Figure 4 For along Figure 2 Cross-sectional view of the middle BB line. Figure 2 This is a top view, showing only the positional relationship between the two metal layers; the thin-film dielectric layer between the two metal layers is not shown.

[0018] like Figures 2-4As shown, the thin-film dielectric constant measurement structure of this embodiment includes: a first measurement unit 21, a second measurement unit 22, and a third measurement unit 23 formed by sequentially stacking a first metal layer 201, a thin-film dielectric layer 202, and a patterned second metal layer 203. The first direction D1 and the second direction D2 are both parallel to the surface of the first metal layer 201, and there is an angle between the first direction D1 and the second direction D2 (90 degrees in this embodiment); the third direction D3 is perpendicular to the surface of the first metal layer 201.

[0019] Specifically, the parameters of the first metal layer 201 and the thin film dielectric layer 202 of the first measurement unit 21, the second measurement unit 22, and the third measurement unit 23 are the same. The same parameters specifically refer to the same film material and the same film thickness. For example, the first metal layer 201 and the thin film dielectric layer 202 are formed on the same substrate using semiconductor processes such as thin film deposition, photolithography, and etching.

[0020] Specifically, the patterned second metal layer of the first measuring unit 21 includes multiple first metal strips 211 connected in series, each first metal strip 211 having a first linewidth W1. The patterned second metal layer of the second measuring unit 22 includes multiple second metal strips 221 connected in series, each second metal strip 221 having a second linewidth W2; wherein the second linewidth W2 is different from the first linewidth W1. The patterned second metal layer of the third measuring unit 23 includes multiple third metal strips 231 connected in parallel, each third metal strip 231 having a third linewidth W3. In this embodiment, the first metal strips 211, second metal strips 221, and third metal strips 231 are all illustrated as three strips; in other embodiments, the number of first metal strips 211 and second metal strips 221 may also be two or more, and the number of third metal strips 231 may also be three or more.

[0021] By measuring the first measuring capacitance C of the first measuring unit 21 测量1 The second measuring capacitor C of the second measuring unit 22 测量2 and the third measuring capacitor C of the third measuring unit 23 测量3 The interlayer capacitance Ca per unit area and the parasitic capacitance, including the edge capacitance Cf per unit length and the intralayer coupling capacitance Cp, are obtained. Based on the actual capacitance after removing the parasitic capacitance, the thin film dielectric constant ε of the thin film dielectric layer 202 under the third linewidth W3 is obtained. Specific measurement methods for the corresponding capacitance can be found in known techniques and will not be elaborated here.

[0022] like Figure 3As shown, since the multiple metal strips in the first measurement unit 21 and the second measurement unit 22 are connected in series, the parasitic capacitance exists only at the edge. The parameters of the first metal layer and the thin-film dielectric layer of the first measurement unit 21 and the second measurement unit 22 are the same, therefore the interlayer capacitance Ca per unit area and the edge capacitance Cf per unit length are the same for both. Assume that the number of first metal strips 211 is n1, and all first metal strips 211 have the same line length L1; the number of second metal strips 221 is n2, and all second metal strips 221 have the same line length L2.

[0023] Then for the first measuring capacitor C of the first measuring unit 21 with a first linewidth W1 测量1 ,have:

[0024] C 测量1 / n1=Ca*L1*W1+Cf*2L1.

[0025] For the second measuring capacitor C of the second measuring unit 22 having the second linewidth W2 测量2 ,have:

[0026] C 测量2 / n2=Ca*L2*W2+Cf*2L2.

[0027] Because n1, n2, L1, L2, W1, W2, C 测量1 C 测量2 Since these are known quantities, Ca and Cf can be calculated.

[0028] To simplify the manufacturing process of the measurement structure and the calculation process, the number of the first metal strip 211 and the number of the second metal strip 221 are set to be the same, for example, both are n; and the line length of the first metal strip 211 and the second metal strip 221 is set to be the same, for example, both are L. Then:

[0029] C 测量1 / n=Ca*L*W1+Cf*2L;

[0030] C 测量2 / n=Ca*L*W2+Cf*2L.

[0031] Therefore, the formulas for calculating Ca and Cf can be simplified to:

[0032] ;

[0033] .

[0034] like Figure 4As shown, since the multiple third metal strips 231 of the third measurement unit 23 are connected in parallel, the parasitic capacitance includes not only the edge capacitance but also the intralayer coupling capacitance Cp. Because the parameters of the first metal layer and the thin-film dielectric layer of the first measurement unit 21, the second measurement unit 22, and the third measurement unit 23 are the same, the interlayer capacitance Ca per unit area and the edge capacitance Cf per unit length are also the same for all three. Assume that all the third metal strips 231 have the same line length, L3.

[0035] Then for the third measuring capacitor C of the third measuring unit 23 having a third linewidth W3 测量3 ,have:

[0036] C 测量3 =Cp +Ca*L3*W3+Cf*2L3.

[0037] Because Ca, Cf, L3, W3, C 测量3 Since Cp is a known quantity, it can be calculated.

[0038] To simplify the manufacturing process of the measurement structure and the calculation process, the length of the third metal strip 231 is set to be the same as the lengths of the first metal strip 211 and the second metal strip 221, for example, both being L. Then:

[0039] C 测量3 =Cp +Ca*L*W3+Cf*2L.

[0040] Therefore, the formula for calculating Cp can be simplified to:

[0041] .

[0042] The dielectric constant ε of the thin film dielectric layer 202 under the third linewidth W3 can be calculated using the following formula:

[0043] .

[0044] Where d is the thickness of the thin film dielectric layer, and ε0 is the vacuum dielectric constant.

[0045] In some embodiments, all the first metal strips 211 have the same line length, all the second metal strips 221 have the same line length, and all the third metal strips 231 have the same line length. The gaps between adjacent first metal strips 211, adjacent second metal strips 221, and adjacent third metal strips 231 are all the same. This simplifies the manufacturing process of the measurement structure and eliminates interference from other variables on the measured capacitance.

[0046] In some embodiments, the number of first metal strips 211 is the same as the number of second metal strips 221. The lengths of the first metal strips 211, second metal strips 221, and third metal strips 231 are all the same. The gaps between adjacent first metal strips 211, adjacent second metal strips 221, and adjacent third metal strips 231 are all the same. This simplifies the manufacturing process of the measurement structure and the calculation process, and also eliminates interference from other variables on the measured capacitance.

[0047] In some embodiments, the third line width W3 is the same as the first line width W1, or the third line width W3 is the same as the second line width W2. The third line width W3 may also be a line width different from the first line width W1 and the second line width W2.

[0048] In some embodiments, the first measurement unit 21, the second measurement unit 22, and the third measurement unit 23 can be fabricated simultaneously using the same process. For example, the first metal layer 201, the thin-film dielectric layer 202, and the second metal layer 203 are formed on the same substrate using semiconductor processes such as thin film deposition, photolithography, and etching; the second metal layer 203 is patterned to form different metal strip patterns in different regions, thereby forming the first measurement unit 21, the second measurement unit 22, and the third measurement unit 23, respectively.

[0049] In some embodiments, the first metal layer 201 is divided into a first region, a second region, and a third region. In the first region, the patterned second metal layer 203 includes multiple first metal strips 211 connected in series. The first metal layer 201, the thin film dielectric layer 202, and the patterned second metal layer 203 in the first region constitute the first measurement unit 21. In the second region, the patterned second metal layer 203 includes multiple second metal strips 221 connected in series. The first metal layer 201, the thin film dielectric layer 202, and the patterned second metal layer 203 in the second region constitute the second measurement unit 22. In the third region, the patterned second metal layer 203 includes multiple third metal strips 231 connected in parallel. The first metal layer 201, the thin film dielectric layer 202, and the patterned second metal layer 203 in the third region constitute the third measurement unit 23. That is, the first measurement unit 21, the second measurement unit 22, and the third measurement unit 23 are fabricated on the same thin film dielectric layer 202, and the same first metal layer 201 lies beneath the thin film dielectric layer 202. In other embodiments, the first measuring unit 21, the second measuring unit 22, and the third measuring unit 23 may also be fabricated on different thin film dielectric layers 202, with different or the same first metal layer 201 under the different thin film dielectric layers 202, but the parameters of the first metal layer 201 are the same, and the parameters of the thin film dielectric layer 202 are the same.

[0050] In some embodiments, the ends of all the first metal strips 211 on the same side are connected in series (as shown in the figure, the left ends are connected in series); the ends of all the second metal strips 221 on the same side are connected in series (as shown in the figure, the left ends are connected in series).

[0051] like Figure 2 As shown, in this embodiment, multiple first metal strips 211 connected in series extend along a first direction D1 and are evenly distributed along a second direction D2 with a first gap G1; all the first metal strips 211 have the same line width along the second direction D2, which is the first line width W1; the first measuring capacitor C of the first measuring unit 21 测量1 The measurement capacitance of the multiple first metal bars 211 connected in series.

[0052] like Figure 2 As shown, in this embodiment, the multiple second metal strips 221 connected in series extend along the first direction D1 and are evenly distributed along the second direction D2 with a second gap G2; all the second metal strips 221 have the same line width along the second direction D2, which is the second line width W2; the second measuring capacitor C of the second measuring unit 22 测量2 The measurement capacitance of the multiple second metal bars 221 connected in series.

[0053] like Figure 2 As shown, in this embodiment, the multiple parallel third metal strips 231 extend along the first direction D1 and are evenly distributed along the second direction D2 with a third gap W3; all the third metal strips 231 have the same line width along the second direction D2, which is the third line width W3; the third measuring capacitor C of the third measuring unit 23 测量3 The measurement capacitance is for the target third metal strip, which is one of the multiple third metal strips connected in parallel, and has third metal strips on both sides.

[0054] To simplify calculations and avoid the influence of variables on measurement results, most variables in this embodiment have the same parameters. In this embodiment, the number of first metal strips 211 is the same as the number of second metal strips 221. In this embodiment, the line lengths of all first metal strips 211, all second metal strips 221, and all third metal strips 231 in the first direction D1 are the same. In this embodiment, the first gap G1, the second gap G2, and the third gap G3 are all the same.

[0055] Following the above embodiment, after parameter optimization, the interlayer capacitance Ca per unit area, the edge capacitance Cf per unit length, the intralayer coupling capacitance Cp, and the thin film dielectric constant ε are calculated using the following formulas:

[0056] ;

[0057] ;

[0058] ;

[0059] .

[0060] Among them, C 测量1 C is the first measuring capacitance of the first measuring unit. 测量2 C is the second measuring capacitor of the second measuring unit. 测量3 The third measuring capacitor of the third measuring unit is n, the number of the first metal strips is L, the line length of the first metal strips is W1, the first line width is W2, the second line width is W3, the third line width is d, the film thickness of the thin film dielectric layer is ε0, and the vacuum dielectric constant is ε0.

[0061] Based on the same inventive concept, the present invention also provides a method for measuring the dielectric constant of a thin film, wherein the method employs the thin film dielectric constant measurement structure described in the above embodiments of the present invention.

[0062] Please see Figure 5This is a schematic diagram illustrating the steps of a method for measuring the dielectric constant of a thin film according to an embodiment of the present invention. Figure 5 As shown, in this embodiment, the method includes the following steps: S1, providing a thin film dielectric constant measurement structure according to the present invention; S2, measuring and acquiring the first measurement capacitor of the first measurement unit, the second measurement capacitor of the second measurement unit, and the third measurement capacitor of the third measurement unit; S3, based on the first measurement capacitor and the second measurement capacitor, acquiring the edge capacitance per unit length of the interlayer capacitance and parasitic capacitance per unit area; S4, based on the third measurement capacitor and the interlayer capacitance and edge capacitance per unit area, acquiring the intralayer coupling capacitance of the parasitic capacitance under the third linewidth of the third measurement capacitor, and then acquiring the actual capacitance under the third linewidth after removing the parasitic capacitance; and S5, acquiring the thin film dielectric constant of the thin film dielectric layer under the third linewidth based on the actual capacitance. The thin film dielectric constant measurement structure and its operation can be found in [reference needed]. Figures 2-4 As shown and described.

[0063] Specifically, in this embodiment, the multiple first metal strips 211 connected in series extend along the first direction D1 and are evenly distributed along the second direction D2 with a first gap G1; all the first metal strips 211 have the same line width along the second direction D2, which is the first line width W1; the first measuring capacitor C of the first measuring unit 21 测量1 The measurement capacitance of the multiple first metal bars 211 connected in series.

[0064] In this embodiment, the multiple second metal strips 221 connected in series extend along the first direction D1 and are evenly distributed along the second direction D2 with a second gap G2; all the second metal strips 221 have the same line width along the second direction D2, which is the second line width W2; the second measuring capacitor C of the second measuring unit 22 测量2 The measurement capacitance of the multiple second metal bars 221 connected in series.

[0065] In this embodiment, the multiple parallel third metal strips 231 extend along the first direction D1 and are evenly distributed along the second direction D2 with a third gap W3; all the third metal strips 231 have the same line width along the second direction D2, which is the third line width W3; the third measuring capacitor C of the third measuring unit 23 测量3 The measurement capacitance is for the target third metal strip, which is one of the multiple third metal strips connected in parallel, and has third metal strips on both sides.

[0066] To simplify calculations and avoid the influence of variables on measurement results, most variables in this embodiment have the same parameters. In this embodiment, the number of first metal strips 211 is the same as the number of second metal strips 221. In this embodiment, the line lengths of all first metal strips 211, all second metal strips 221, and all third metal strips 231 in the first direction D1 are the same. In this embodiment, the first gap G1, the second gap G2, and the third gap G3 are all the same.

[0067] Following the above embodiment, after parameter optimization, the interlayer capacitance Ca per unit area, the edge capacitance Cf per unit length, the intralayer coupling capacitance Cp, and the thin film dielectric constant ε are calculated using the following formulas:

[0068] ;

[0069] ;

[0070] ;

[0071] .

[0072] Among them, C 测量1 C is the first measuring capacitance of the first measuring unit. 测量2 C is the second measuring capacitor of the second measuring unit. 测量3 The third measuring capacitor of the third measuring unit is n, the number of the first metal strips is L, the line length of the first metal strips is W1, the first line width is W2, the second line width is W3, the third line width is d, the film thickness of the thin film dielectric layer is ε0, and the vacuum dielectric constant is ε0.

[0073] As can be seen from the above, the thin film dielectric constant measurement structure and method provided in this embodiment, by setting up first and second measurement units with the same structure (both including multiple metal strips connected in series) but different linewidths, obtains the edge capacitance among interlayer capacitance and parasitic capacitance through capacitance measurement and calculation. Furthermore, by setting up a third measurement unit with a different structure (including multiple metal strips connected in parallel), obtains the intralayer coupling capacitance among parasitic capacitances through capacitance measurement and calculation. Therefore, using the thin film dielectric constant measurement structure provided in this embodiment, parasitic capacitance interference, including edge capacitance and intralayer coupling capacitance, can be measured and eliminated. By obtaining the actual capacitance, the thin film dielectric constant of the thin film dielectric layer under the corresponding linewidth can be obtained, effectively improving the accuracy of capacitance and dielectric constant measurements.

[0074] It should be noted that the terms "comprising" and "having," and their variations, used in this invention document are intended to cover non-exclusive inclusion. The terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence, unless explicitly indicated by the context; it should be understood that such use of data can be interchanged where appropriate. The term "one or more" depends at least in part on the context and can be used to describe features, structures, or characteristics in a singular sense, or in a plural sense to describe combinations of features, structures, or characteristics. The term "based on" can be understood as not necessarily intended to express an exclusive set of factors, but can instead, also at least in part on the context, allow for the presence of other factors that are not necessarily explicitly described. Furthermore, embodiments and features in embodiments of this invention can be combined with each other without conflict. In addition, descriptions of well-known components and technologies have been omitted in the above description to avoid unnecessarily obscuring the concepts of this invention. In the various embodiments described above, each embodiment focuses on its differences from other embodiments; similar / identical parts between embodiments can be referred to mutually.

[0075] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A thin film dielectric constant measurement structure, characterized in that, include: A first measurement unit, a second measurement unit, and a third measurement unit are formed by sequentially stacking a first metal layer, a thin film dielectric layer, and a patterned second metal layer; The parameters of the first metal layer of the first measurement unit, the second measurement unit, and the third measurement unit are the same, as are the parameters of the thin film dielectric layer; The patterned second metal layer of the first measuring unit includes: a plurality of first metal strips, the plurality of first metal strips extending along a first direction and evenly distributed along a second direction with a first gap, all the first metal strips being connected at one end on the same side in the second direction, all the first metal strips having the same line width along the second direction, which is a first line width, wherein the first direction and the second direction are both parallel to the surface of the first metal layer and there is an angle between the first direction and the second direction; The patterned second metal layer of the second measuring unit includes: multiple second metal strips, which extend along the first direction and are evenly distributed along the second direction with a second gap. In the second direction, all the second metal strips are connected at one end on the same side. All the second metal strips have the same line width along the second direction, which is a second line width. The second line width is different from the first line width. The patterned second metal layer of the third measuring unit includes: multiple third metal strips, which extend along the first direction and are evenly distributed along the second direction with a third gap, and all the third metal strips have the same line width along the second direction, which is a third line width; By measuring the first measuring capacitance of the first measuring unit, the second measuring capacitance of the second measuring unit, and the third measuring capacitance of the third measuring unit, the interlayer capacitance per unit area and the parasitic capacitance including the edge capacitance per unit length and the intralayer coupling capacitance are obtained. Based on the actual capacitance after removing the parasitic capacitance, the thin film dielectric constant of the thin film dielectric layer under the third linewidth is obtained. The first measuring capacitance of the first measuring unit is the measuring capacitance of the plurality of first metal strips, the second measuring capacitance of the second measuring unit is the measuring capacitance of the plurality of second metal strips, and the third measuring capacitance of the third measuring unit is the measuring capacitance of the target third metal strip, which is one of the plurality of third metal strips having third metal strips on both sides.

2. The thin film dielectric constant measurement structure according to claim 1, characterized in that, The first metal layer is divided into a first region, a second region, and a third region; In the first region, the patterned second metal layer includes the plurality of first metal strips, and the first metal layer, the thin film dielectric layer and the patterned second metal layer in the first region constitute the first measurement unit; In the second region, the patterned second metal layer includes the plurality of second metal strips, and the first metal layer, the thin film dielectric layer and the patterned second metal layer in the second region constitute the second measurement unit; In the third region, the patterned second metal layer includes the plurality of third metal strips, and the first metal layer, the thin film dielectric layer, and the patterned second metal layer in the third region constitute a third measurement unit.

3. The thin film dielectric constant measurement structure according to claim 1, characterized in that, The first measuring unit, the second measuring unit, and the third measuring unit are manufactured synchronously using the same process.

4. The thin film dielectric constant measurement structure according to claim 1, characterized in that, In the first direction, all the first metal strips have the same line length, all the second metal strips have the same line length, and all the third metal strips have the same line length; the first gap, the second gap, and the third gap are all the same.

5. The thin film dielectric constant measurement structure according to claim 1, characterized in that, The third line width is the same as the first line width, or the third line width is the same as the second line width.

6. The thin film dielectric constant measurement structure according to claim 1, characterized in that, The number of the first metal strips is the same as the number of the second metal strips. In the first direction, the line length of all the first metal strips, all the second metal strips, and all the third metal strips is the same. The first gap, the second gap, and the third gap are all the same.

7. The thin film dielectric constant measurement structure according to claim 6, characterized in that, The interlayer capacitance Ca per unit area, the edge capacitance Cf per unit length, the intralayer coupling capacitance Cp, and the thin film dielectric constant ε are calculated using the following formulas: ， ， ， ， Among them, C 测量1 C is the first measuring capacitance of the first measuring unit. 测量2 C is the second measuring capacitor of the second measuring unit. 测量3 The third measuring capacitor of the third measuring unit is n, the number of the first metal strips is L, the line length of the first metal strips is W1, the first line width is W2, the second line width is W3, the third line width is d, the film thickness of the thin film dielectric layer is ε0, and the vacuum dielectric constant is ε0.

8. A method for measuring the dielectric constant of a thin film, characterized in that, Includes the following steps: Provide a thin film dielectric constant measurement structure as described in any one of claims 1 to 6; The first measuring capacitance of the first measuring unit, the second measuring capacitance of the second measuring unit, and the third measuring capacitance of the third measuring unit are measured and obtained. Based on the first and second measuring capacitors, the interlayer capacitance per unit area and the edge capacitance per unit length in the parasitic capacitance are obtained. Based on the third measured capacitance, the interlayer capacitance per unit area, and the edge capacitance per unit length, the intralayer coupling capacitance in the parasitic capacitance under the third linewidth of the third measured capacitance is obtained, and then the actual capacitance after removing the parasitic capacitance under the third linewidth is obtained. The dielectric constant of the thin film dielectric layer at the third linewidth is obtained based on the actual capacitance.

9. The method according to claim 8, characterized in that, The interlayer capacitance Ca per unit area, the edge capacitance Cf per unit length, the intralayer coupling capacitance Cp, and the thin film dielectric constant ε are calculated using the following formulas: ， ， ， ， Among them, C 测量1 C is the first measuring capacitance of the first measuring unit. 测量2 C is the second measuring capacitor of the second measuring unit. 测量3 The third measuring capacitor of the third measuring unit is n, the number of the first metal strips is L, the line length of the first metal strips is W1, the first line width is W2, the second line width is W3, the third line width is d, the film thickness of the thin film dielectric layer is ε0, and the vacuum dielectric constant is ε0.

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