A testing method, a testing structure, and an application

Abstract

The present application discloses a test method, a test structure and an application, belonging to the field of quantum chip manufacturing. The test structure includes a first electrical component, a reference resonant component and a to-be-tested resonant component respectively coupled thereto, wherein the to-be-tested resonant component is configured with an interconnection structure. By detecting that a signal is transmitted through the first electrical component, the measured values of the resonant frequencies of the reference resonant component and the to-be-tested resonant component can be determined according to the corresponding feedback signals. Thus, by comparing the measured values of the resonant frequencies of the two, the connectivity of the interconnection structure provided in the to-be-tested resonant component can be determined.

Description

Technical Field

[0001] This application belongs to the field of quantum chip fabrication, and particularly relates to a testing method, a testing structure, and an application thereof. Background Art

[0002] Through-Silicon Via (TSV) interconnection technology refers to a technology that realizes interconnection between different chips or different sides of a chip by fabricating vias in the Z-axis direction on a silicon wafer and filling conductive materials inside the vias. TSV interconnection technology can achieve three-dimensional interconnection and integration between chips. It has shorter signal lines, smaller signal delay and crosstalk, and can exhibit higher packaging efficiency under the same planar size.

[0003] Therefore, as a very promising chip interconnection technology, the industry generally expects to introduce it into the manufacturing process of quantum chips - for example, superconducting quantum chips as concerned in this article.

[0004] Since the operation and measurement of superconducting quantum chips both involve radio frequency signals, when superconducting quantum chips apply TSV technology for interconnection, it is necessary to consider whether the TSV interconnection meets the requirements of radio frequency signal transmission. Therefore, there is an urgent need for a solution that can characterize the performance of TSV interconnection structures in superconducting quantum chips for transmitting radio frequency signals - such as continuity. Summary of the Invention

[0005] In view of this, this application discloses a testing method, a testing structure, and an application thereof, which can be used to determine the continuity of TSVs, thereby helping to verify the fabrication process parameters of TSVs, shorten the chip fabrication cycle, and improve the chip fabrication quality.

[0006] The solution of this application is implemented through the following content.

[0007] In a first aspect, this application proposes a testing structure for determining the connectivity of a TSV interconnection structure.

[0008] The testing structure includes:

[0009] A reference resonant element having a first designed resonant frequency;

[0010] A DUT (Device Under Test) resonant element having a first element and a second element configured to be connected through the interconnection structure and on different planes. The DUT resonant element is configured based on design parameters that are preset according to the first designed resonant frequency;

[0011] A first electrical component, independently coupled to a first element of a reference resonant element and a resonant element under test respectively, is configured to receive a detection signal to determine a measured value of the resonant frequency of the resonant element under test and a measured value of the resonant frequency of the reference resonant element.

[0012] In the above test structure, the reference resonant element and the resonant element under test respectively have corresponding resonant frequencies. And since the resonant element under test is configured with design parameters preset based on the resonant frequency of the reference resonant element, a high-quality manufactured resonant element under test will have a resonant frequency corresponding to and matching the design parameters. Therefore, the actual resonant frequency of the resonant element under test can be obtained by measuring through the first electrical component. Thus, when comparing the measured resonant frequency of the resonant element under test with its designed resonant frequency, the continuity of the interconnect structure can be determined through the comparison result. The designed resonant frequency is related to, or even equal to, the resonant frequency of the reference resonant element, that is, the designed resonant frequency of the resonant element under test (i.e., the second designed resonant frequency) can be inferred by measuring the resonant frequency of the reference resonant element.

[0013] Therefore, for example, when the measured value of the resonant frequency of the resonant element under test is the same as or close to a certain degree to the measured value of the resonant frequency of the reference resonant element, it can be considered that the interconnect structure is connected. When the measured value of the resonant frequency of the resonant element under test is different from or deviated to a certain degree from the measured value of the resonant frequency of the reference resonant element, it can be considered that the interconnect structure is disconnected.

[0014] In a second aspect, an example of the present application proposes a test structure for determining the connectivity of a through-silicon via interconnect structure, which includes:

[0015] A read bus extending along a first preset direction;

[0016] At least one interconnect unit, and each interconnect unit includes n interconnect structures;

[0017] At least one resonator fabricated according to design resonant frequency parameters and corresponding one-to-one with at least one interconnect unit, arranged side by side at intervals along the first preset direction, and each resonator extends from a first end to a second end along a second preset direction different from the first preset direction;

[0018] Each resonator is interrupted by the interconnect structures in the corresponding interconnect unit to form m sub-elements, and the m sub-elements are sequentially connected through the interconnect structures in the interconnect unit;

[0019] Where m = n + 1, n is an integer greater than or equal to 1, and the resonator is coupled to the read bus through the sub-element located at the first end.

[0020] In a third aspect, examples of the present application propose the use of the aforementioned test structure in implementing a test method to determine the connectivity of a through silicon via interconnect structure.

[0021] In a fourth aspect, an example of the present application proposes a test method for determining connectivity of a through silicon via interconnect structure, the test method comprising:

[0022] A test structure is obtained, wherein the test structure has a first electrical element, a reference electrical element and an electrical element to be tested, wherein the first electrical element is coupled to the reference electrical element and the electrical element to be tested respectively; wherein the electrical element to be tested is made based on the reference electrical element interrupted by an interconnection structure, and has a proximal element and a distal element connected by the interconnection structure and in different planes, and the electrical element to be tested is coupled to the first electrical element via the proximal element;

[0023] Transmitting a microwave detection signal to the reference electrical component and the electrical component to be tested through the first electrical component;

[0024] Calculating a reference resonant frequency of a reference electrical component and a measured resonant frequency of the electrical component to be measured from a feedback signal obtained from the first electrical component to form a resonant frequency result set;

[0025] The connectivity of the interconnect structure is confirmed according to a preset pattern based on the resonant frequency result set.

[0026] Beneficial effects:

[0027] Compared with the prior art, in order to measure the quality of the interconnection structure, such as continuity, the test structure in the example of the present application is configured with a reference resonant element and a resonant element to be tested, which is constructed by connecting its components through the interconnection structure. Moreover, a first electrical element is configured on this basis. Thus, when the test method is implemented, the resonant frequencies of the reference resonant element and the resonant element to be tested can be measured by the first electrical element, and the connectivity of the aforementioned interconnection structure can be inferred and confirmed based on the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0029] Figure 1 A schematic diagram of the structure of the test structure provided in an embodiment of the present application when viewed from above;

[0030] Figure 2 Public Figure 1 A schematic diagram of a partial cross-sectional structure of the test structure in the axonometric direction;

[0031] Figure 3Schematic diagram of another test structure provided by an embodiment of the present application in a top-down view;

[0032] Figure 4 Schematic diagrams of two other test structures in an embodiment of the present application in a top-down view are shown.

[0033] Figure 5 Schematic diagram of the steps of the test method in an embodiment of the present application is disclosed.

[0034] Icon: 101 - substrate; 102 - interconnect structure; 103 - first element; 104 - second element; 201 - reference resonant element; 202 - device-under-test resonant element; 202a - device-under-test resonant element; 203 - first circuit element; 204 - second circuit element. Detailed implementation manners

[0035] As mentioned above, radio frequency signals are often required in superconducting quantum chips for manipulation and reading. Therefore, the stable transmission of radio frequency signals is very important. On the other hand, in order to improve the integration level, etc., through-silicon via (TSV) interconnect technology can be used in superconducting quantum chips for three-dimensional layout and packaging of various circuits and components. Therefore, when these three-dimensionally laid out circuits or components need to be associated with radio frequency signals, it is necessary to ensure good connectivity of the TSV interconnect structure (such as on-off, quality in the connected state, etc.). However, how to confirm this is a difficult point.

[0036] As far as the inventors of the present application know, currently, the on-off state of the interconnect structure is mainly judged by detecting and characterizing the DC characteristics of the interconnect structure. For example, it is judged by measuring resistance - an open circuit indicates that the interconnect structure is connected, and a short circuit indicates that the connection is good. However, this does not or is not always effectively equivalent to the performance of the interconnect structure for radio frequency signals. In some other attempts, radio frequency performance is characterized by measuring insertion loss, reflection, etc. However, some current superconducting quantum chips need to be cooled to an extremely low temperature such as 10 mK to work properly. At such a temperature, various radio frequency devices are connected to the front-end and back-end of the chip, and the TiN attached to the TSV interconnect structure will enter the superconducting state, so its insertion loss and reflection are extremely small, making it difficult to characterize.

[0037] In view of this, different from the above attempts, in the examples of the present application, the inventors propose a test structure and a test method that can be implemented through this test structure. It can be used to judge the connectivity of the TSV interconnect structure, thereby improving the manufacturing quality of superconducting quantum chips, shortening their manufacturing cycle, and improving manufacturing efficiency. It can be understood that based on the solution of the examples of the present application, in some other fields or other types of quantum chips, the scenarios with requirements for the connectivity of the TSV interconnect structure associated with radio frequency signal performance are also applicable.

[0038] Generally speaking, the solution of the present application example mainly judges the connectivity of the through-silicon via (TSV) interconnect structure by measuring the resonance frequency and according to the measurement results. Therefore, a reference device and a device under test are selected and configured as a whole. Among them, the device under test is provided with an interconnect structure, and correspondingly, the reference device is not configured with an interconnect structure. And the reference device and the device under test have the same, or close or expected deviation in the designed resonance frequency, for example, the difference frequency is 50 MHz.

[0039] Therefore, the reference device and the device under test are fabricated based on these designed resonance frequencies. Then, in theory, when the manufacturing process is good (including good connectivity of the interconnect structure), the actual resonance frequencies of the reference device and the device under test will be related in the aforementioned design manner - for example, the same or close or with an expected deviation.

[0040] When there are problems in aspects such as the manufacturing process of the interconnect structure, the quality of the interconnect structure deteriorates, so its connectivity also deteriorates. At the same time, since the reference device is not configured with an interconnect structure, the aforementioned manufacturing process problems will not affect the reference device. Then, the resonance frequency of the device under test will be recognizably different from that of the reference device. By identifying this difference, it can be determined that there are quality problems in the interconnect structure, that is, its connectivity is poor.

[0041] Based on such an understanding, the inventor proposed such a test method that can be used to implement a test structure for determining the connectivity of the through-silicon via interconnect structure in the example.

[0042] Please refer to Figure 1 and Figure 2 . This test structure includes a first circuit element 203 (or the first electrical element), and a reference resonant element 201 and a device-under-test resonant element 202 that are respectively coupled to the first circuit element 203.

[0043] Among them, Figure 1 is a top-view structural schematic diagram of the test structure configured on the substrate 101 in the example of the present application; among them, for the convenience of description and display, the first element 103 and the second element 104 included in the device-under-test resonant element 202 are respectively expressed in a visible manner, but in combination with Figure 2 it can be seen that the first element 103 and the second element 104 are respectively located on two surfaces (front and back) of the substrate 101; that is, each element is selectively located on the front or back of a chip. Therefore, in Figure 1 the front top-view direction shown, in the actual element, the first element 103 is visible on the front, while the second element 104 is not visible on the back.

[0044] Among them, Figure 2 isFigure 1 Schematic diagram of a partial cross-sectional structure, which mainly discloses the distribution of the interconnect structure 102 in the substrate 101 and its mating relationship with the first element 103 and the second element 104 at both ends. In the field of superconducting quantum chips, the interconnect structure 102 is usually selected as a superconducting material and is fabricated by forming holes (such as etching) in the substrate and then plating a thin film of superconducting material on the inner wall. In Figure 2 the structure shown, the interconnect structure 102 is represented as a roughly hollow cylindrical structure. In some other examples, it can also be constructed as a solid cylinder under the condition that the process is feasible. According to Figure 1 and Figure 2 it can be known that the first circuit element 203 is coplanarly configured with the reference resonant element 201; while the first element 103 in the measured resonant element 202 is coplanar with the first electrical element, and the second element 104 is non-coplanar with it. Figure 2 in, the first element and the second element are respectively provided with holes corresponding to the interconnect structure 102; the sizes of the holes shown therein and the relative sizes of the two elements are only for illustrative purposes and do not constitute specific limitations.

[0045] The reference resonant element 201 therein has a first designed resonant frequency; the measured resonant element 202 has a second designed resonant frequency; the designed resonant frequency can be obtained by simulation calculation using electromagnetic simulation software, and thus the corresponding structural design parameters can also be obtained. Under ideal conditions, when these two resonant elements are fabricated as expected and with high quality, the measured value of the resonant frequency of the reference resonant element 201 is usually close to, or even equal to, the first designed resonant frequency; similarly, the measured value of the resonant frequency of the measured resonant element 202 is usually close to, or even equal to, the second designed resonant frequency. And, through appropriate design, the first designed resonant frequency and the second designed resonant frequency can be made equal, or the difference between the two is within a given range.

[0046] In the implementation process of the test method, the first circuit element 203 can receive the detection signal and determine the measured value of the resonant frequency of the reference resonant element 201 (the first measured value) and the measured value of the resonant frequency of the measured resonant element 202 (the second measured value) through the response results of the two resonant elements coupled thereto through existing methods such as signal processing and calculation. Such a measurement method can be realized, for example, based on the matching coupling structure between the readout bus and the readout resonator in the superconducting quantum chip. Therefore, the first circuit element 203 can be the readout bus, and the reference resonant element 201 and the measured resonant element 202 can be their corresponding readout resonators.

[0047] As a solution for verifying the through-silicon via interconnect structure 102, the measured resonant element 202 is configured with the interconnect structure 102. That is, if the reference resonant element 201 is a continuously configured resonant cavity structure, such as a coplanar waveguide; then, the measured resonant element 202 can correspondingly be a coplanar waveguide interrupted by the through-silicon via interconnect structure 102.

[0048] Therefore, the measured resonant element 202 can have a first element 103 and a second element 104; where the interconnect structure 102 is used as the demarcation point, the side adjacent to the first electrical element is the first element 103, and the side far from the first electrical element is the second element 104. Here, an example of a measured resonant element configured with one interconnect structure is used for illustration; it can be known that when a measured resonant element is configured with at least two interconnect structures, then this measured resonant element can have at least three elements; such as the first element, the second element, the third element, the fourth element, and so on, and so forth.

[0049] Considering the existence of the through-silicon via interconnect structure 102, the first element 103 and the second element 104 therein are distributed on different planes. Therefore, in some examples, the test structure is configured on the substrate 101, and exemplarily as described above, it can be that the first electrical element is on the front side of the substrate 101, the reference resonant element 201 is on the front side of the substrate 101, the first element 103 of the measured resonant element 202 is on the front side of the substrate 101, the second element 104 of the measured resonant element 202 is on the back side of the substrate 101, and the interconnect structure 102 located within the substrate 101 extends from the front side of the substrate 101 to the back side of the substrate 101 and is connected to the first element 103 and the second element 104 at both ends respectively.

[0050] Due to reasons such as manufacturing processes and materials, there may be differences between the designed resonant frequency of the resonant element and the measured value of the resonant frequency obtained after actual manufacturing. In the examples of this application, the measured resonant element 202 configured is designed and manufactured based on the reference resonant element 201. That is, the measured resonant element 202 is manufactured based on design parameters, and these design parameters are preset according to the first designed resonant frequency of the reference resonant element 201. The design parameters therein are, for example, the materials selected in the manufacturing process, the environment and process conditions, the structural parameters, and so on. Based on this, the measured values of the resonant frequencies of the well-manufactured measured resonant element 202 and the reference resonant element 201 are close or the same or meet the expected deviation.

[0051] In the examples of the present application, the number of the resonating elements 202 to be measured can be freely selected. When there are multiple resonating elements 202 to be measured, these resonating elements 202 to be measured can adopt the same structural design, so as to avoid the problems of low accuracy or non-repeatability of the results in some cases caused by the deviation of the measurement results when there is a single or a small number of resonating elements 202 to be measured. Further, the number of the interconnecting structures and the positions of the interconnecting structures (which can be measured by the distance from the first circuit element 203) in different resonating elements 202 to be measured can also be selected as needed, for example, all the same, all different, or partially the same and partially different, etc.

[0052] In order to study the influence caused by configuring the interconnecting structure 102 at different positions in the resonating element 202 to be measured, the resonating elements 202 to be measured can be classified into multiple groups according to the different positions of the interconnecting structure 102. Each group contains at least one resonating element 202 to be measured, and the positions of the interconnecting structures 102 of the resonating elements 202 to be measured in the same group are the same. In some such examples, the first element 103 of each resonating element 202 has a first parameter, and the second element 104 has a second parameter. Based on this, the resonance frequency of the resonating element 202 to be measured is jointly determined by the first parameter and the second parameter. The first parameter and the second parameter are, for example, their lengths, so the two together constitute the length of the resonating element 202 to be measured. For different groups or different types of resonating elements 202 to be measured, the first parameter can be configured to be different.

[0053] For example, in Figure 3 the shown test structure, there are two types (each type includes one, and a total of two for the two types) of resonating elements 202 to be measured. The interconnecting structure 102 of one resonating element 202 is close to the first circuit element 203, while the interconnecting structure 102 of the other resonating element 202a is far from the first circuit element 203. And the length of the first element 103 of the resonating element 202 is less than the length of the first element 103 of the resonating element 202a. Correspondingly, the length of the second element 104 of the resonating element 202 is greater than the length of the second element 104 of the resonating element 202a.

[0054] Further, based on some measurement requirements, a second circuit element 204 can also be configured in some examples. Similar to the first circuit element 203, it is also independently coupled to the reference resonating element 201 and the second element 104 of the resonating element 202 respectively. Therefore, both ends of the reference resonating element 201 are coupled to the first circuit element 203 and the second circuit element 204 respectively; and the resonating element 202 ( Figure 4The two ends (not marked in the figure) are also respectively coupled to the first and second circuit elements 204. The second circuit element 204 may have the same structure as the first electrical element, and functionally, it can also be used to measure the resonance frequencies of the reference resonator element 201 and the resonator element under test 202 to obtain corresponding measurement values. For example, Figure 4 as shown in Figure A in

[0055] Furthermore, based on Figure A, more than one interconnect structure 102 can be configured on the resonator element under test 202. For example, Figure 4 two interconnect structures 102 are configured for each resonator element under test 202 in Figure B in

[0056] According to Figure 4 the structure shown in Figure A in Figure 4 on the basis of considering the configuration of one interconnect structure 102 on the resonator element under test 202 and its position, as shown in Figure B in

[0057] the additional interconnect structure 102 is configured on the longer one of the first element 103 and the second element 104, so that the first segment element and the second segment element can be generated by the interruption of the original first element 103 by the additional interconnect structure 102. Then, at this time, the corresponding third segment element is the original second element 104. Similarly, the first segment element is the original first element 103, and the second segment element and the third segment element are generated by the interruption of the original second element 104 by the newly added interconnect structure 102. Figure 4 as shown in

[0058] Correspondingly, each read resonator is configured with an interconnection unit, and each interconnection unit has a positive integer number (n) of interconnection structures 102. In other words, in such an example, each read resonator is interrupted by the interconnection structures 102 in its corresponding interconnection unit to form a number of sub-elements (m, and m = n + 1) that is one more than the number of the corresponding interconnection structures 102. In this example, by the theoretical resonance frequency of the read resonator and the measured value of the actual resonance frequency, it is also possible to attempt to determine whether the configured interconnection structures are on or off.

[0059] Due to the stability of the manufacturing process and the deviation between the theoretical design and the actual process, it would be beneficial to configure a resonator without the interconnection structure 102 as a reference resonator / reference resonant element 201, as described above. This reference resonator can have substantially the same structure and arrangement as the resonator with the interconnection structure 102. In addition, two read buses can also be selected to be configured in this test structure. Correspondingly, these two read buses can be coupled to the sub-elements at the first end and the sub-elements at the second end of the resonator respectively. The two can independently measure the resonance frequency from both ends of the resonator.

[0060] In the above structure, for the measurement of the resonance frequency, those skilled in the art can use the technical means of microwave resonators in related fields for measurement. To avoid repetition, it can be briefly described as: λ = v / f; where v is the wave velocity, f is the frequency, μ is the magnetic permeability, and ε is the dielectric constant. Then the calculation formula for the frequency is Therefore, after the substrate is determined, μ and ε are constants, and it can be calculated that the frequency f of the resonator is related to the length of the resonator. Then for Figure 1 the test structure in, if the interconnection structure 102 is disconnected, only the resonance frequency of the reference resonant element 201 can be measured, while for the resonance frequency of the resonator under test 202, since the length of the resonant cavity (the first element 103) is too short, no effective value can be measured. The second element 104 is disconnected by the interconnection structure, so its resonance frequency cannot be measured either because it is not coupled to the first circuit element 203. That is, only one resonance frequency can be measured, which belongs to the reference resonant element. If the interconnection structure 102 is not disconnected / fully connected, the resonance frequencies of the reference resonant element 201 and the resonator under test 202 can be measured, that is, two resonance frequencies can be measured.

[0061] Similarly, in Figure 3In the test structure shown, if the interconnect structure 102 is completely disconnected, only the resonant frequencies of the reference resonant element 201 and the resonant element under test 202a can be measured (mainly contributed by its first element 103, while its second element 104 cannot be measured because the interconnect structure 102 is disconnected), that is, two resonant frequencies. However, for the resonant frequency of the resonant element under test 202, the effective value cannot be measured because the length of the resonant cavity (first element 103) is too short. If the interconnect structure 102 is not disconnected / fully connected, the resonant frequencies of the reference resonant element 201 and the two resonant elements under test 202 can be measured, that is, three resonant frequencies can be measured.

[0062] Combined with the above test structure, a test method for determining the connectivity of the through-silicon via interconnect structure 102 can be implemented. Moreover, this connectivity can be used to verify the design process and parameters of the through-silicon via interconnect structure 102 in chip manufacturing, so as to obtain better manufacturing processes and design parameters for the through-silicon via interconnect structure 102, and then obtain a high-quality through-silicon via interconnect structure 102.

[0063] Furthermore, according to the described test structure, the connectivity of the through-silicon via interconnect structure 102 determined by this test method can also well reflect its performance in transmitting radio frequency signals. Therefore, it has great potential and value in the manufacturing of superconducting quantum chips.

[0064] Generally speaking, as Figure 5 shown, the test method mainly includes the following steps:

[0065] S101. Obtain the test structure.

[0066] This test structure can be fabricated with reference to the content disclosed above. Generally, the test structure can include a first electrical component, a reference electrical component, and an electrical component to be measured. Among them, the electrical component to be measured is fabricated based on the reference electrical component interrupted by the interconnect structure 102. In other words, except for the interconnect structure 102, the electrical component to be measured can have the same or approximate design structure parameters, materials, and process fabrication conditions as the reference electrical component.

[0067] The electrical component to be measured can be fabricated in the following way:

[0068] On the upper and lower surfaces of the substrate 101, a corresponding material is fabricated respectively - which can be described as proximally distributed proximal elements and distally distributed distal elements - and. Among them, the proximal elements are close to the first electrical component, and the distal elements are far from the first electrical component. The substrate is drilled along the thickness, and the corresponding material (such as a conductor material, etc.) is filled in the hole, and its two ends are electrically contacted and connected to the aforementioned corresponding material. In the process related to integrated circuits, the fabrication of the through-silicon via interconnect structure 102 generally includes operations such as through-hole fabrication, through-hole insulation, and barrier layer, seed layer, and filling plating.

[0069] Thus, the first electrical component is coupled to the reference electrical component, and the electrical component under test is coupled to the first electrical component through the aforementioned proximal component.

[0070] S102. Measure the resonant frequency using a microwave detection signal.

[0071] According to the structure of the test structure, it can be selected to transmit the microwave detection signal from the first electrical component to the reference electrical component and the electrical component under test. Among them, the first electrical component can be selected as a transmission line such as a coplanar waveguide, which can be used to transmit microwave signals. In a superconducting quantum chip, it can be described as a readout line (such as a Readout Line). The reference electrical component and the electrical component under test can be resonator components (such as a ReadoutResonator) coupled to the first electrical component, and can also be made of a coplanar waveguide. Generally, the quality factor is calculated by the ratio of the resonant frequency to the bandwidth. By way of example, for the example of a superconducting quantum chip, measuring the resonant frequency of the resonant component using the first electrical component can be obtained by using a vector network analyzer to test and obtain corresponding data, and then obtaining the corresponding Q value through data fitting; details are not described herein to avoid redundancy.

[0072] S103. Obtain data from the feedback signal and confirm the connectivity of the interconnect structure 102 accordingly.

[0073] Due to the coupling relationship between the first electrical component and the reference electrical component and the electrical component under test respectively, the microwave signal input through the first electrical component can act on the two reference electrical components and the electrical component under test, and then the feedback signal can be sent to the first electrical component. By using microwave and electrical devices in the art for measurement, the reference resonant frequency of the reference electrical component and the measured resonant frequency of the electrical component under test, that is, the measured values of the resonant frequencies of the two components, can be calculated, and thus a set of resonant frequency results can be formed. Further, according to the set of resonant frequency results in a preset mode, the connectivity of the interconnect structure 102 can be confirmed.

[0074] Since the set of resonant frequency combinations includes the measured value of the resonant frequency of the reference electrical component and the measured value of the resonant frequency of the electrical component under test. Therefore, according to different utilization - preset mode - methods of these measured values, the connectivity of the interconnect structure 102 can be confirmed.

[0075] For example, since the reference electrical component is not fabricated through the through-silicon via interconnect structure 102, in theory, its resonant frequency can always be measured. However, for the electrical component under test, since it involves the fabrication of the through-silicon via interconnect structure 102, the quality of the interconnect structure 102 will affect whether its corresponding resonant frequency can be measured. When the connectivity of each interconnect structure 102 is good, the number of measured components and the number of measured resonant frequencies should be the same. Then, when using the number of measured resonant frequencies in the resonant frequency result set as a basis, when the number of measured resonant frequencies in the resonant frequency result set is the same as the number of electrical components to be tested, it is determined that the connectivity of the interconnect structure 102 is good. Conversely, if the numbers are different, it can be determined that there is a poor connectivity in one or more interconnect structures 102.

[0076] Furthermore, as described above, the magnitude of the resonant frequency is associated with the length of the resonator. And when the resonant element is fabricated through the through-silicon via interconnect structure 102 and coupled to the first electrical component, if the connectivity of the interconnect structure 102 is poor, in theory, the resonant frequency measured corresponds to that of the part adjacent to the first electrical component (such as the proximal element mentioned above, for example Figure 1 the first element 103 in ). Therefore, when the length of the proximal element is short, the measured resonant frequency will be very high, and thus it can be considered that the resonant frequency is not measured in actual applications.

[0077] Even further, when the length of the part of the resonant element 202 under test close to the first electrical component (proximal element) is relatively longer, while the length of the part far from the first electrical component (distal element, such as Figure 1 the second element 104 in ) is shorter, then when the connectivity of the interconnect structure 102 is poor, the resonant frequency of the proximal element can be measured - but there will be an obvious and recognizable difference between its measured value and the measured value of the resonant frequency of the electrical component under test when the connectivity of the interconnect structure 102 is good. Therefore, based on this, the aforementioned preset mode can also include: confirming the connectivity of the interconnect structure 102 by comparing the reference resonant frequency and the measured resonant frequency in the resonant frequency result set. The reference resonant frequency can reflect the measured value of the resonant frequency of the electrical component under test when the connectivity of the interconnect structure 102 is good; this is because the electrical component under test is fabricated according to the design parameters determined based on the reference electrical component. And it can be known that in this case, when the reference resonant frequency is equal to or the difference is within the preset range of the measured resonant frequency, it can be determined that the connectivity of the interconnect structure 102 is good.

[0078] In addition, for the interconnect structure 102, the resonant elements fabricated based thereon, and the coupling structure with the first electrical element, when applied to, for example, a superconducting quantum chip, an important performance index parameter of concern is, for example, the quality factor (Q-value, Q-factor, Quality Factor). The method for calculating the quality factor can adopt the existing technologies in the art, and the present application does not make specific limitations thereto. For example, by the frequency method, that is, calculating the Q-value in the frequency domain, such as the frequency conversion method, etc.

[0079] Therefore, the connectivity of the above-mentioned through-silicon via interconnect structure 102 can also include evaluating the quality factor of the components based thereon; and the higher the quality factor, that is, the Q-value, the better the connectivity of the interconnect structure 102. Accordingly, after confirming that the connectivity of the interconnect structure 102 meets the requirements through the resonant frequency result set, the quality factor can be further measured. That is, in some examples, the test method can further include: when the connectivity of the interconnect structure 102 is good, measuring the quality factors of the electrical element to be tested and the reference electrical element, and performing an optional comparison. Through the comparison, the element with the best quality factor can be selected from the comparison objects, so that the electrical element to be tested with a more ideal setting position, structural parameters, and corresponding manufacturing process of the interconnect structure 102 can be obtained. Furthermore, when actually fabricating the chip, the corresponding solution can be implemented.

[0080] As a further optimization option, in some examples, the interconnect structure 102 can also be selected for structural adjustment to obtain better manufacturing conditions for the interconnect structure 102 used in some cases. For example, taking the interconnect structure 102 as a cylinder, when it is determined that the interconnect structure 102 is connected by the number of resonant frequencies in the resonant frequency result set or the comparison result, the diameters of different cylindrical interconnect structures 102 and the related quality factors can be further investigated.

[0081] Therefore, the test method can further include: when it is determined that the connectivity of the interconnect structure 102 is good through the resonant frequency and there are at least two corresponding electrical elements to be tested, then the quality factors of the corresponding electrical elements to be tested and the reference electrical element can be measured. Then, the electrical element to be tested with the smallest absolute value of the difference between the quality factor and the quality factor of the reference electrical element is selected from these determined quality factors as the element with good radio frequency performance.

[0082] In the above examples, the quality factor of the electrical component under test that meets the requirements is compared with the quality factor of the reference electrical component. In other examples, a ratio can be made between the quality factors of the electrical components under test that meet the requirements. In other words, when the connectivity of the corresponding interconnect structure 102 is confirmed to be good and there are at least two corresponding electrical components to be tested, the corresponding electrical components to be tested can be measured, and the electrical component to be tested with the largest quality factor among them is determined to have good radio frequency performance.

[0083] In short, in some examples of the present application, the test of the connectivity of the through-silicon via interconnect structure 102 can include a judgment on whether it is connected, and further include a judgment on the connection quality in the case of connection. Whether it is connected can be judged by comparing the measured value of the resonance frequency to be measured with the measured value of the reference resonance frequency. The connection quality is mainly determined by comparing the numerical values of the quality factors, and the numerical comparison can also include the comparison of the quality factors of the components corresponding to the resonance frequency to be measured and the reference resonance frequency, or the comparison of the quality factors between the components corresponding to the resonance frequency to be measured.

[0084] The embodiments described above with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the foregoing content elaborates on the various embodiments of the present application in conjunction with the accompanying drawings. However, those of ordinary skill in the art can understand that in the various embodiments of the present application, many technical details are presented for the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the present application can still be implemented. The division of each example is for convenience of description and should not constitute any limitation on the specific implementation manner of the present application. The various embodiments can be combined and cross-referenced with each other on the premise of not being contradictory.

[0085] It should be noted that the terms "first", "second", etc. in the specification, claims, and above-mentioned drawings of the present application are used to distinguish similar objects and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here.

[0086] In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0087] The structure, features, and effects of the present application have been described in detail based on the embodiments shown in the drawings. The above is only the preferred embodiment of the present application. However, the present application is not limited to the scope of implementation shown in the drawings. Any changes made in accordance with the concept of the present application, or equivalent embodiments modified into equivalent changes, that still do not exceed the spirit covered by the specification and the drawings should be within the protection scope of the present application.

Claims

1. A test structure for determining the connectivity of a through-silicon via interconnect structure, characterized in that, The test structure includes: a reference resonant element having a first designed resonant frequency; A resonant element under test, comprising a first element and a second element configured to be connected by the interconnection structure and to be skewed, the resonant element under test being configured based on design parameters, and the design parameters being preset and generated according to the first design resonant frequency, and the interconnection structure being a superconducting material; a first electrical element, independently coupled to the reference resonant element and the first element of the measured resonant element; The first electrical element is configured to receive a detection signal to determine a measured value of the resonant frequency of the measured resonant element and a measured value of the resonant frequency of the reference resonant element; The measured value of the resonant frequency of the measured resonant element is compared with the measured value of the resonant frequency of the reference resonant element, and the continuity of the interconnection structure is determined by the comparison result.

2. The test structure according to claim 1, wherein The test structure includes at least two groups of resonant elements to be tested that are independently configured, and each group includes at least one resonant element to be tested; Each first element has a first parameter, each second element has a second parameter, and the first parameter and the second parameter jointly determine the resonant frequency of the measured resonant element; The first parameters of the measured resonant elements in the same group are the same, and the first parameters of the measured resonant elements in different groups are different.

3. The test structure according to claim 2, wherein The first parameter is the length of the first element, and the second parameter is the length of the second element.

4. The test structure according to any one of claims 1 to 3, wherein The test structure further includes a second circuit element, independently coupled to the reference resonant element and the second element of the resonant element under test; The second circuit element is configured to receive the detection signal to determine a measured value of the resonant frequency of the measured resonant element and a measured value of the resonant frequency of the reference resonant element.

5. The test structure according to claim 4, characterized in that, The measured resonant element comprises a first section element, a second section element and a third section element connected in sequence through two interconnection structures; Wherein, the first segment element is coupled to the first electrical element, and the third segment element is coupled to the second circuit element; The first section element and the second section element are provided by the first element, and the third section element is provided by the second element; or the first section element is provided by the first element, and the second section element and the third section element are provided by the second element.

6. The test structure according to claim 5, characterized in that The first section elements and the third section elements are arranged in the same plane.

7. The test structure according to claim 4, characterized in that, The reference resonant element is arranged coplanar with the first electrical element; And / or, the first element is arranged in the same plane as the first electrical element, and the second element is arranged in a different plane than the second circuit element; Alternatively, the measured resonant element has a second designed resonant frequency, and the first designed resonant frequency is equal to the second designed resonant frequency or the difference between the first designed resonant frequency and the second designed resonant frequency is within a given range.

8. A test structure for determining the connectivity of a through-silicon via interconnect structure, characterized in that, The test structure includes: A read bus extending along a first preset direction; at least one interconnection unit, each interconnection unit includes n interconnection structures, n is an integer greater than or equal to 1, and the interconnection unit is a column; and at least one resonator arranged side by side and at intervals along the first preset direction, the at least one resonator corresponding to the at least one interconnection unit one by one; Each resonator is manufactured according to the designed resonant frequency parameters, and each resonator extends from the first end to the second end along a second preset direction different from the first preset direction; Each resonator is interrupted by an interconnection structure in a corresponding interconnection unit to form m sub-elements, and m=n+1; wherein the m sub-elements are sequentially connected through the interconnection structure in the interconnection unit, and the resonator is coupled to the read bus through the sub-element located at the first end; The test structure is used to determine whether the interconnection structure configured by the resonator is on or off through the theoretical resonant frequency of the resonator and the actual resonant frequency measurement value.

9. The test structure according to claim 8, wherein, The readout bus and the resonator are respectively coplanar waveguides; and / or, in the at least one interconnection unit, there are at least two interconnection units in which the number of interconnection structures is different; And / or, the test structure includes a reference resonant element having a given resonant frequency, the reference resonant element is extended along the second preset direction, and the reference resonant element is coupled to the read bus.

10. The test structure according to claim 8, wherein, The test structure includes two read buses, and the two read buses are arranged in parallel and at intervals; The subelement at the first end and the subelement at the second end of each resonator are coupled to the two read buses respectively.

11. The test structure according to claim 10, characterized in that, The test structure includes a reference resonant element having a given resonant frequency, and two ends of the reference resonant element are respectively coupled to the two read buses.

12. Use of the test structure according to any one of claims 1 to 11 for implementing a test method to determine the connectivity of a through silicon via interconnect structure.

13. A testing method for determining the connectivity of a through-silicon via interconnect structure, characterized in that, The test method includes: A test structure is obtained, wherein the test structure has a first electrical element, a reference electrical element and an electrical element to be tested, wherein the first electrical element is coupled to the reference electrical element; wherein the electrical element to be tested is made based on the reference electrical element interrupted by an interconnection structure, and the electrical element to be tested has a proximal element and a distal element connected by the interconnection structure and in different planes, and the electrical element to be tested is coupled to the first electrical element via the proximal element; Transmitting a microwave detection signal to the reference electrical component and the electrical component to be tested through the first electrical component; Calculating a reference resonant frequency of the reference electrical component and a measured resonant frequency of the electrical component to be measured based on a feedback signal obtained from the first electrical component to form a resonant frequency result set; The connectivity of the interconnection structure is confirmed according to a preset mode based on the resonant frequency result set.

14. The test method according to claim 13, wherein The preset modes include: When the number of measured resonant frequencies in the resonant frequency result set is the same as the number of the electrical components to be tested, it is determined that the connectivity of the interconnection structure is good.

15. The test method according to claim 13, wherein The preset modes include: The connectivity of the interconnect structure is confirmed by comparing a reference resonant frequency in the resonant frequency result set with the measured resonant frequency.

16. The testing method according to claim 15, characterized in that Confirming the connectivity of the interconnection structure by comparing the reference resonant frequency in the resonant frequency result set with the measured resonant frequency comprises: When the reference resonance frequency is equal to the measured resonance frequency or the difference is within a preset range, it is determined that the connectivity of the interconnection structure is good.

17. The test method according to any one of claims 14 to 16, characterized in that, The test method also includes: When the connectivity of the interconnect structure is good, the quality factors of the electrical component under test and the reference electrical component are measured and optionally compared.

18. The test method according to claim 17, characterized in that, There are multiple electrical components under test, and the interconnect structure of each electrical component under test is a cylinder, and at least some of the interconnect structures of the electrical components under test have different diameters; The test method further includes: a first operation or a second operation; The first operation includes: when there are at least two electrical components under test with good connectivity of the corresponding interconnect structure, measuring the quality factors of the corresponding electrical components under test and the reference electrical component, and optionally determining that the electrical component under test with the smallest absolute value of the difference in quality factor from the reference electrical component has good radio frequency performance; The second operation includes: when there are at least two electrical components under test with good connectivity of the corresponding interconnect structure, measuring the corresponding electrical components under test, and optionally determining that the electrical component under test with the largest quality factor has good radio frequency performance.

Images