Thin film dielectric constant measuring structure and measuring method thereof

Abstract

The invention discloses a thin film dielectric constant measuring structure and a measuring method thereof. According to the invention, the first measuring unit and the second measuring unit which respectively comprise a plurality of metal strips connected in series and have different line widths are arranged, interlayer capacitance and fringe capacitance in parasitic capacitance are obtained through capacitance measurement and calculation, and a third measuring unit comprising a plurality of metal strips connected in parallel is further arranged. Obtaining the in-layer coupling capacitance in the stray capacitance through capacitance measurement and calculation; by adopting the thin film dielectric constant measurement structure provided by the embodiment of the invention, parasitic capacitance interference including interlayer capacitance, edge capacitance and in-layer coupling capacitance can be measured and eliminated, the thin film dielectric constant of the thin film dielectric layer under the corresponding line width is obtained by obtaining the actual capacitance, and the capacitance and dielectric constant measurement precision is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuits, and in particular to a thin film dielectric constant measurement structure and a measurement method thereof. Background Art

[0002] With the development of VLSI, high-speed, high-density, and multifunctional integrated circuits have higher and higher requirements for device feature size and chip wiring density. Therefore, the number of metal wire layers will be increased and the distance between metal wires will be reduced during chip design. However, problems such as signal RC delay and power consumption caused by resistance and capacitance coupling have become increasingly prominent. Using low-dielectric constant (Low-K) materials instead of silicon dioxide as intermetallic dielectrics can effectively reduce parasitic capacitance between metal layers and reduce RC delay. Low-dielectric constant materials will play an important role in the future VLSI manufacturing, so the measurement of the K value (i.e. dielectric constant, ε) of low-dielectric constant materials is also particularly important.

[0003] See also Figure 1 , which is a schematic diagram of the existing capacitance method for measuring the K value of low dielectric constant. Currently, the capacitance method is often used to measure the K value of low dielectric constant. This method uses a capacitance structure composed of metal / insulating layer / semiconductor (such as Figure 1 As shown), the CV curve of the low dielectric constant film is measured. Then according to the relationship ε=(C 测量 *d) / (ε0*A), the K value of low dielectric constant materials can be calculated. Where ε is the dielectric constant of the material, C 测量 is the capacitance measured in the accumulation region, d is the film thickness of the low dielectric constant material, ε0 = 8.854 × 10 -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 Very small, generally in the pf level. At this time, parasitic capacitances such as edge capacitance and interlayer coupling capacitance can no longer be ignored, that is, 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, improving measurement accuracy becomes 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 a measurement method thereof, which can measure and eliminate the interference of parasitic capacitance to obtain the actual capacitance, thereby improving the accuracy of capacitance and dielectric constant measurement.

[0005] To solve the above problem, 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 a first metal layer, a thin film dielectric layer and a patterned second metal layer stacked in sequence; the parameters of the first metal layer of the first measurement unit, the second measurement unit and the third measurement unit are the same, and the parameters of the thin film dielectric layer are the same; the patterned second metal layer of the first measurement unit comprises: a plurality of first metal strips connected in series, the first metal strips having a first line width; the patterned second metal layer of the second measurement unit comprises: a plurality of second metal strips connected in series, the second metal strips having a second line width, the second line width being different from the first line width; the patterned second metal layer of the third measurement unit comprises: a plurality of third metal strips connected in parallel, the third metal strips having a 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 parasitic capacitance including the interlayer capacitance per unit area, the edge capacitance per unit length and the intra-layer coupling capacitance is obtained, so as to obtain the thin film dielectric constant of the thin film dielectric layer under the third line width according to the actual capacitance after removing the parasitic capacitance.

[0006] In some embodiments, the first metal layer is divided into a first area, a second area and a third area; in the first area, 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 area constitute the first measurement unit; in the second area, 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 area constitute the second measurement unit; in the third area, 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 area 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 line lengths of the first metal strips, the second metal strips, and the third metal strips are all the same; the gap between two adjacent first metal strips, the gap between two adjacent second metal strips, and the gap between two adjacent third metal strips are all the same.

[0008] To solve the above problem, an embodiment of the present invention further provides a method for measuring a thin film dielectric constant, characterized in that it includes the following steps: providing a thin film dielectric constant measurement structure as described in the present invention; measuring and obtaining a first measurement capacitance of the first measurement unit, a second measurement capacitance of the second measurement unit, and a third measurement capacitance of the third measurement unit; obtaining an interlayer capacitance per unit area and an edge capacitance per unit length in parasitic capacitance according to the first measurement capacitance and the second measurement capacitance; obtaining an intralayer coupling capacitance in a parasitic capacitance under a third line width of the third measurement capacitance according to the third measurement capacitance and the interlayer capacitance per unit area and the edge capacitance per unit length, and further obtaining an actual capacitance after removing the parasitic capacitance under the third line width; obtaining the thin film dielectric constant of the thin film dielectric layer under the third line width according to the actual capacitance.

[0009] The above technical scheme, by setting the first and second measurement units with the same structure (both including multiple metal strips connected in series) and different line widths, obtain the interlayer capacitance and edge capacitance in the parasitic capacitance through capacitance measurement and calculation, and further set the third measurement unit with a different structure (including multiple metal strips connected in parallel), obtain the intralayer coupling capacitance in the parasitic capacitance through capacitance measurement and calculation; thus, by using the thin film dielectric constant measurement structure provided in this embodiment, the parasitic capacitance interference including the interlayer capacitance, edge capacitance, and intralayer coupling capacitance can be measured and eliminated, and the thin film dielectric constant of the thin film dielectric layer under the corresponding line width can be obtained by obtaining the actual capacitance, thereby effectively improving the accuracy of capacitance and dielectric constant measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0011] Figure 1 Schematic diagram of measuring the K value of low dielectric constant using the existing capacitance method.

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

[0013] Figure 3 For along Figure 2 Sectional view along line AA;

[0014] Figure 4 For along Figure 2 Sectional view of the middle BB line;

[0015] Figure 5A schematic diagram of the steps of a method for measuring a thin film dielectric constant provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0017] Please also read Figure 2 to Figure 4 ,in, Figure 2 A schematic diagram of a thin film dielectric constant measurement structure provided by an embodiment of the present invention, Figure 3 For along Figure 2 The cross-section diagram along the AA line. Figure 4 For along Figure 2 Cross-section along line BB. Figure 2 This is a top view, which only illustrates the positional relationship between the two metal layers, and the thin film dielectric layer between the two metal layers is not illustrated.

[0018] like Figure 2 to Figure 4 As shown, the thin film dielectric constant measurement structure described in this embodiment includes: a first measurement unit 21, a second measurement unit 22 and a third measurement unit 23 formed by a first metal layer 201, a thin film dielectric layer 202 and a patterned second metal layer 203 stacked in sequence. Among them, 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 of the first measurement unit 21, the second measurement unit 22, and the third measurement unit 23 are the same, and the parameters of the thin film dielectric layer 202 are the same. The same parameters specifically refer to the same film layer material and the same film layer thickness. For example, the first metal layer 201 and the thin film dielectric layer 202 are formed on the same substrate through semiconductor processes such as thin film, photolithography, and etching.

[0020] Specifically, the second patterned metal layer of the first measurement unit 21 includes: a plurality of first metal strips 211 connected in series, and the first metal strips 211 have a first line width W1. The second patterned metal layer of the second measurement unit 22 includes: a plurality of second metal strips 221 connected in series, and the second metal strips 221 have a second line width W2; wherein the second line width W2 is different from the first line width W1. The second patterned metal layer of the third measurement unit 23 includes: a plurality of third metal strips 231 connected in parallel, and the third metal strips 231 have a third line width W3. In this embodiment, the first metal strip 211, the second metal strip 221, and the third metal strip 231 are all illustrated as three strips; in other embodiments, the number of the first metal strips 211 and the second metal strips 221 may also be 2 or more than 3, and the number of the third metal strips 231 may also be more than 3.

[0021] By measuring the first measurement capacitance C of the first measurement unit 21 测量1 , the second measuring capacitance 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 , obtain the parasitic capacitance including the interlayer capacitance Ca per unit area, the edge capacitance Cf per unit length, and the intra-layer coupling capacitance Cp, so as to obtain the film dielectric constant ε of the thin film dielectric layer 202 under the third line width W3 according to the actual capacitance after removing the parasitic capacitance. The specific measurement method of the corresponding capacitance can refer to the known technology and will not be repeated here.

[0022] like Figure 3 As 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 only exists in the interlayer capacitance and the edge capacitance. 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, so the interlayer capacitance Ca per unit area and the edge capacitance Cf per unit length of the two are the same. Assume that the number of the first metal strips 211 is n1, and the line lengths of all the first metal strips 211 are the same, namely, L1; the number of the second metal strips 221 is n2, and the line lengths of all the second metal strips 221 are the same, namely, L2.

[0023] Then, for the first measurement capacitance C of the first measurement unit 21 having the first line width W1, 测量1 ,have:

[0024] C 测量1 / n1=Ca*L1*W1+Cf*2L1.

[0025] For the second measurement capacitance C of the second measurement unit 22 having the second line width W2 测量2 ,have:

[0026] C 测量2 / n2=Ca*L2*W2+Cf*2L2.

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

[0028] In order to simplify the manufacturing process of the measurement structure and the calculation process, the number of the first metal strips 211 and the number of the second metal strips 221 are set to be the same, for example, both are n strips; and the line lengths of the first metal strips 211 and the second metal strips 221 are 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 calculation formula of Ca and Cf can be simplified as follows:

[0032]

[0033] like Figure 4 As shown, since the multiple third metal strips 231 of the third measurement unit 23 are connected in parallel, the parasitic capacitance has not only the interlayer capacitance and the edge capacitance, but also the intralayer coupling capacitance Cp. Since 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 of the three are the same. It is assumed that the line lengths of all the third metal strips 231 are the same, which is L3.

[0034] Then, for the third measurement capacitance C of the third measurement unit 23 having the third line width W3, 测量3 ,have:

[0035] C 测量3 =Cp+Ca*L3*W3+Cf*2L3.

[0036] Due to Ca, Cf, L3, W3, C 测量3 is a known quantity, so Cp can be calculated.

[0037] In order to simplify the manufacturing process of the measurement structure and the calculation process, the line length of the third metal strip 231 is set to be the same as the line lengths of the first metal strip 211 and the second metal strip 221, for example, both are L. Then:

[0038] C 测量3 =Cp+Ca*L*W3+Cf*2L.

[0039] Therefore, the calculation formula of Cp can be simplified as:

[0040] Cp=C 测量3 -Ca*L*W3-Cf*2L.

[0041] The thin film dielectric constant ε of the thin film dielectric layer 202 at the third line width W3 can be calculated by the following formula:

[0042]

[0043] Wherein, d is the film thickness of the thin film dielectric layer, and ε0 is the vacuum dielectric constant.

[0044] In some embodiments, the line lengths of all the first metal strips 211 are the same, the line lengths of all the second metal strips 221 are the same, and the line lengths of all the third metal strips 231 are the same. The gaps between two adjacent first metal strips 211, the gaps between two adjacent second metal strips 221, and the gaps between two adjacent third metal strips 231 are all the same. In this way, the manufacturing process of the measurement structure can be simplified, and the interference of other variables on the measured capacitance can be eliminated.

[0045] In some embodiments, the number of the first metal strips 211 is the same as the number of the second metal strips 221. The line lengths of the first metal strips 211, the second metal strips 221, and the third metal strips 231 are all the same. The gap between two adjacent first metal strips 211, the gap between two adjacent second metal strips 221, and the gap between two adjacent third metal strips 231 are all the same. In this way, the manufacturing process of the measurement structure and the calculation process can be simplified, and the interference of other variables on the measured capacitance can also be eliminated.

[0046] 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.

[0047] In some embodiments, the first measurement unit 21, the second measurement unit 22, and the third measurement unit 23 can be simultaneously manufactured 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 by semiconductor processes such as thin film, 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.

[0048] 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 the plurality of first metal strips 211 connected in series, and 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 the plurality of second metal strips 221 connected in series, and 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 the plurality of third metal strips 231 connected in parallel, and 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 prepared on the same thin film dielectric layer 202, and the same first metal layer 201 is below the thin film dielectric layer 202. In other embodiments, the first measurement unit 21, the second measurement unit 22 and the third measurement unit 23 may also be respectively prepared on different thin film dielectric layers 202, and different or the same first metal layer 201 may be provided under the different thin film dielectric layers 202, but the parameters of the first metal layer 201 and the parameters of the thin film dielectric layer 202 are the same.

[0049] In some embodiments, all ends of the first metal strips 211 on the same side are connected in series (the left ends are connected in series as shown in the figure); all ends of the second metal strips 221 on the same side are connected in series (the left ends are connected in series as shown in the figure).

[0050] like Figure 2 As shown, in this embodiment, a plurality of first metal strips 211 connected in series extend along a first direction D1 and are evenly distributed with a first gap G1 along a second direction D2; the line widths of all the first metal strips 211 along the second direction D2 are the same, which is the first line width W1; the first measurement capacitor C of the first measurement unit 21 测量1is the measured capacitance of the plurality of first metal strips 211 connected in series.

[0051] like Figure 2 As shown, in this embodiment, the plurality of second metal strips 221 connected in series extend along the first direction D1 and are evenly distributed with a second gap G2 along the second direction D2; the line widths of all the second metal strips 221 along the second direction D2 are the same, which is the second line width W2; the second measurement capacitor C of the second measurement unit 22 测量2 is the measured capacitance of the plurality of second metal strips 221 connected in series.

[0052] like Figure 2 As shown, in this embodiment, the plurality of third metal strips 231 connected in parallel extend along the first direction D1 and are evenly distributed with a third gap W3 along the second direction D2; the line widths of all the third metal strips 231 along the second direction D2 are the same, which is the third line width W3; the third measurement capacitor C of the third measurement unit 23 测量3 The measured capacitance is a target third metal strip, where the target third metal strip is one of the plurality of third metal strips connected in parallel and has third metal strips on both sides.

[0053] In order to simplify the calculation and avoid the influence of variables on the measurement results, the parameters of most variables in this embodiment are the same. In this embodiment, the number of the first metal strips 211 is the same as the number of the second metal strips 221. In this embodiment, the line lengths of all the first metal strips 211, all the second metal strips 221, and all the third metal strips 231 in the first direction D1 are the same. In this embodiment, the first gap G1 is the same as the second gap G2 and the third gap G3.

[0054] Continuing with the above embodiment, after the parameters are optimized, the interlayer capacitance Ca per unit area, the edge capacitance Cf per unit length, the intralayer coupling capacitance Cp and the film dielectric constant ε are calculated by the following formula:

[0055]

[0056] Cp=C 测量3 -Ca*L*W3-Cf*2L;

[0057]

[0058] Among them, C 测量1 is the first measurement capacitance of the first measurement unit, C 测量2 is the second measurement capacitance of the second measurement unit, C 测量3is the third measurement capacitance of the third measurement unit, n is the number of the first metal strips, L is the line length of the first metal strip, W1 is the first line width, W2 is the second line width, W3 is the third line width, d is the film thickness of the thin film dielectric layer, and ε0 is the vacuum dielectric constant.

[0059] Based on the same inventive concept, the present invention further provides a method for measuring a thin film dielectric constant, and the measuring method adopts the thin film dielectric constant measuring structure described in the above embodiment of the present invention.

[0060] See also Figure 5 , which is a schematic diagram of the steps of a method for measuring the dielectric constant of a thin film provided by 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 obtaining 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; S3, obtaining the interlayer capacitance per unit area and the edge capacitance per unit length in the parasitic capacitance according to the first measurement capacitance and the second measurement capacitance; S4, obtaining the intra-layer coupling capacitance in the parasitic capacitance under the third line width of the third measurement capacitance according to the third measurement capacitance and the interlayer capacitance per unit area and the edge capacitance per unit length, and then obtaining the actual capacitance after removing the parasitic capacitance under the third line width; and S5, obtaining the thin film dielectric constant of the thin film dielectric layer under the third line width according to the actual capacitance. The thin film dielectric constant measurement structure and its working method can be referred to. Figure 2 to Figure 4 Shown and described.

[0061] Specifically, in this embodiment, the plurality of first metal strips 211 connected in series extend along the first direction D1 and are evenly distributed with a first gap G1 along the second direction D2; the line widths of all the first metal strips 211 along the second direction D2 are the same, which is the first line width W1; the first measurement capacitor C of the first measurement unit 21 is 测量1 is the measured capacitance of the plurality of first metal strips 211 connected in series.

[0062] In this embodiment, the plurality of second metal strips 221 connected in series extend along the first direction D1 and are evenly distributed with a second gap G2 along the second direction D2; the line widths of all the second metal strips 221 along the second direction D2 are the same, which is the second line width W2; the second measurement capacitor C of the second measurement unit 22 测量2 is the measured capacitance of the plurality of second metal strips 221 connected in series.

[0063] In this embodiment, the plurality of third metal strips 231 connected in parallel extend along the first direction D1 and are evenly distributed with a third gap W3 along the second direction D2; the line widths of all the third metal strips 231 along the second direction D2 are the same, which is the third line width W3; the third measurement capacitor C of the third measurement unit 23 测量3 The measured capacitance is a target third metal strip, where the target third metal strip is one of the plurality of third metal strips connected in parallel and has third metal strips on both sides.

[0064] In order to simplify the calculation and avoid the influence of variables on the measurement results, the parameters of most variables in this embodiment are the same. In this embodiment, the number of the first metal strips 211 is the same as the number of the second metal strips 221. In this embodiment, the line lengths of all the first metal strips 211, all the second metal strips 221, and all the third metal strips 231 in the first direction D1 are the same. In this embodiment, the first gap G1 is the same as the second gap G2 and the third gap G3.

[0065] Continuing with the above embodiment, after the parameters are optimized, the interlayer capacitance Ca per unit area, the edge capacitance Cf per unit length, the intralayer coupling capacitance Cp and the film dielectric constant ε are calculated by the following formula:

[0066]

[0067] Cp=C 测量3 -Ca*L*W3-Cf*2L;

[0068]

[0069] Among them, C 测量1 is the first measurement capacitance of the first measurement unit, C 测量2 is the second measurement capacitance of the second measurement unit, C 测量3 is the third measurement capacitance of the third measurement unit, n is the number of the first metal strips, L is the line length of the first metal strip, W1 is the first line width, W2 is the second line width, W3 is the third line width, d is the film thickness of the thin film dielectric layer, and ε0 is the vacuum dielectric constant.

[0070] From the above content, it can be seen that the thin film dielectric constant measurement structure and the measurement method thereof provided in the present embodiment, by setting the first and second measurement units with the same structure (both including multiple metal strips connected in series) and different line widths, obtain the interlayer capacitance and edge capacitance in the parasitic capacitance through capacitance measurement and calculation, and further set the third measurement unit with a different structure (including multiple metal strips connected in parallel), obtain the intra-layer coupling capacitance in the parasitic capacitance through capacitance measurement and calculation; thus, by using the thin film dielectric constant measurement structure provided in the present embodiment, parasitic capacitance interference including interlayer capacitance, edge capacitance, and intra-layer coupling capacitance can be measured and eliminated, and the thin film dielectric constant of the thin film dielectric layer under the corresponding line width can be obtained by obtaining the actual capacitance, thereby effectively improving the accuracy of capacitance and dielectric constant measurement.

[0071] It should be noted that the terms "including" and "having" and their variations involved in the document of the present invention are intended to cover non-exclusive inclusions. The terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence, unless the context clearly indicates, and it should be understood that the data used in this way can be interchanged under appropriate circumstances. 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 can be used to describe features, structures or combinations of features in a plural sense. The term "based on" can be understood as not necessarily intended to express a set of exclusive factors, but can alternatively, also at least in part depending on the context, allow the presence of other factors that are not necessarily explicitly described. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict. In addition, in the above description, the description of well-known components and technologies is omitted to avoid unnecessary confusion of the concept of the present invention. In the above embodiments, each embodiment focuses on the differences from other embodiments, and the same / similar parts between the embodiments can be referred to each other.

[0072] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should also be regarded as 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 formed by a first metal layer, a thin film dielectric layer and a patterned second metal layer stacked in sequence; The parameters of the first metal layer of the first measurement unit, the second measurement unit and the third measurement unit are the same, and the parameters of the thin film dielectric layer are the same; The patterned second metal layer of the first measurement unit includes: a plurality of first metal strips connected in series, the first metal strips having a first line width; The patterned second metal layer of the second measurement unit includes: a plurality of second metal strips connected in series, the second metal strips having a 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: a plurality of third metal strips connected in parallel, the third metal strips having a third line width; By measuring the first measured capacitance of the first measuring unit, the second measured capacitance of the second measuring unit, and the third measured capacitance of the third measuring unit, the parasitic capacitance including the interlayer capacitance per unit area, the edge capacitance per unit length, and the intra-layer coupling capacitance is obtained, so as to obtain the thin film dielectric constant of the thin film dielectric layer at the third line width according to the actual capacitance after removing the parasitic capacitance.

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

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

4. The thin film dielectric constant measurement structure according to claim 1, characterized in that: All the first metal strips are connected in series at one end on the same side; The ends of all the second metal strips on the same side are connected in series.

5. The thin film dielectric constant measurement structure according to claim 1, characterized in that: 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 gap between two adjacent first metal strips, the gap between two adjacent second metal strips, and the gap between two adjacent third metal strips are all the same.

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; The line lengths of the first metal strip, the second metal strip, and the third metal strip are all the same; The gap between two adjacent first metal strips, the gap between two adjacent second metal strips, and the gap between two adjacent third metal strips are all the same.

7. 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.

8. The thin film dielectric constant measurement structure according to claim 1, characterized in that: The plurality of first metal strips connected in series extend along a first direction and are evenly distributed with a first gap along a second direction, the line widths of all the first metal strips along the second direction are the same, which is the first line width, and the first measurement capacitance of the first measurement unit is the measurement capacitance of the plurality of first metal strips connected in series; The plurality of second metal strips connected in series extend along the first direction and are evenly distributed with second gaps along the second direction, the line widths of all the second metal strips along the second direction are the same, which is the second line width, and the second measurement capacitance of the second measurement unit is the measurement capacitance of the plurality of second metal strips connected in series; The plurality of third metal strips connected in parallel extend along the first direction and are evenly distributed with a third gap along the second direction; the line widths of all the third metal strips along the second direction are the same, which is the third line width; 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 plurality of third metal strips connected in parallel that has third metal strips on both sides; The number of the first metal strips is the same as the number of the second metal strips, the line lengths of all the first metal strips, all the second metal strips, and all the third metal strips in the first direction are the same, and the first gap is the same as the second gap and the third gap; 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.

9. The thin film dielectric constant measurement structure 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 film dielectric constant ε are calculated by the following formula: Cp=C 测量3 -Ca*L*W3-Cf*2L Among them, C 测量1 is the first measurement capacitance of the first measurement unit, C 测量2 is the second measurement capacitance of the second measurement unit, C 测量3 is the third measurement capacitance of the third measurement unit, n is the number of the first metal strips, L is the line length of the first metal strip, W1 is the first line width, W2 is the second line width, W3 is the third line width, d is the film thickness of the thin film dielectric layer, and ε0 is the vacuum dielectric constant.

10. A method for measuring a dielectric constant of a thin film, characterized in that: The steps include: Providing a thin film dielectric constant measurement structure as claimed in any one of claims 1 to 8; Measuring and acquiring a first measured capacitance of the first measuring unit, a second measured capacitance of the second measuring unit, and a third measured capacitance of the third measuring unit; According to the first measured capacitance and the second measured capacitance, obtaining the interlayer capacitance per unit area and the edge capacitance per unit length in the parasitic capacitance; According to 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 line width of the third measured capacitance is obtained, and then the actual capacitance after removing the parasitic capacitance under the third line width is obtained; The thin film dielectric constant of the thin film dielectric layer at the third line width is obtained according to the actual capacitance.

11. The method according to claim 10, characterized in that The interlayer capacitance Ca per unit area, the edge capacitance Cf per unit length, the intralayer coupling capacitance Cp, and the film dielectric constant ε are calculated by the following formula: Cp=C 测量3 -Ca*L*W3-Cf*2L Among them, C 测量1 is the first measurement capacitance of the first measurement unit, C 测量2 is the second measurement capacitance of the second measurement unit, C 测量3 is the third measurement capacitance of the third measurement unit, n is the number of the first metal strips, L is the line length of the first metal strip, W1 is the first line width, W2 is the second line width, W3 is the third line width, d is the film thickness of the thin film dielectric layer, and ε0 is the vacuum dielectric constant.

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