Semiconductor test structure, test method, and test system

Abstract

The present invention provides a semiconductor test structure, test method and test system. The semiconductor test structure includes: a common pad for receiving a common voltage; a plurality of test circuits, all electrically connected to the common pad, each test circuit including: a branch pad, electrically connected to the first test end of the component to be tested, for receiving a test voltage, the test voltage being greater than the common voltage; a switch unit, a control end of which is electrically connected to the branch pad, a first end of which is electrically connected to the second test end of the component to be tested, and a second end of which is electrically connected to the common pad; a protection unit, a first end of which is electrically connected to the second test end of the component to be tested, and a second end of which is connected to the common pad. The above technical solution achieves the purpose of shortening the total test time by connecting multiple test circuits in parallel to the common pad and testing multiple components to be tested at the same time; and a switch unit and a protection unit are set in each test circuit to avoid affecting other test circuits when the component to be tested fails.

Description

Technical Field

[0001] The present invention relates to the field of semiconductors, and in particular to a semiconductor test structure, a test method, and a test system. Background Art

[0002] In the semiconductor industry, time-dependent dielectric breakdown (TDDB) testing and voltage ramp (V-ramp) testing are commonly used to verify dielectric layer reliability. Due to differences in dielectric layers, reliability test structures with varying lengths, types, and structures are often designed.

[0003] See also Figure 1 , which is a schematic diagram of the structure of the dielectric layer test structure in the prior art. Figure 1 As shown, the dielectric layer test structure includes a structure to be tested 10, a first pad 11 and a second pad 12. One end of the structure to be tested 10 receives a test voltage VT through the first pad 11, and the other end is grounded (i.e., a zero voltage V0 is applied) through the second pad 12. The failure of the structure to be tested 10 is determined by monitoring the current change on the grounded second pad 12. When the structure to be tested 10 is broken down, the first pad 11 and the second pad 12 at both ends are connected, and a large current flows from the first pad 11 through the broken-down structure to be tested 10 to the second pad 12. When multiple structures to be tested 10 need to be tested, testing them one by one takes a long time, which in turn affects the mass production plan of process products.

[0004] Therefore, how to shorten the total testing time of multiple structures to be tested and improve production efficiency without affecting the accuracy of the test results is a problem that needs to be solved at present. Summary of the Invention

[0005] The technical problem to be solved by the present invention is how to shorten the total testing time of multiple structures to be tested and improve production efficiency without affecting the accuracy of the test results, and to provide a semiconductor test structure, test method and test system.

[0006] To solve the above-mentioned problem, the present invention provides a semiconductor test structure, comprising: a common pad for receiving a common voltage; a plurality of test circuits, each electrically connected to the common pad, each test circuit being used to perform a dielectric layer reliability test on a component under test, each test circuit comprising: a branch pad electrically connected to a first test terminal of the component under test and being used to receive a test voltage, wherein the test voltage is greater than the common voltage; a switch unit, wherein a control terminal of the switch unit is electrically connected to the branch pad, a first terminal of the switch unit is electrically connected to a second test terminal of the component under test, and a second terminal of the switch unit is electrically connected to the common pad, the switch unit being turned on in response to a breakdown of the component under test to increase the current on the branch pad to a preset threshold current to determine that the component under test has failed; and a protection unit, wherein a first terminal of the protection unit is electrically connected to the second test terminal of the component under test and a second terminal of the protection unit is connected to the common pad, and being used to disconnect the current path between the component under test and the common pad when a breakdown occurs in the component under test; wherein, when the component under test is determined to have failed, application of the test voltage to the branch pad of the test circuit where the component under test is located is stopped.

[0007] In order to solve the above problems, the present invention provides a test system, comprising: multiple components to be tested, each of the components to be tested having a first test end and a second test end; a semiconductor test structure, the semiconductor test structure adopts the semiconductor test structure described in the present invention, and is used to simultaneously perform dielectric layer reliability tests on multiple components to be tested, and in response to the breakdown of the component to be tested electrically connected to the test circuit, a switch unit in a test circuit is turned on, and the current on the branch pad of the test circuit is raised to a preset threshold current, the component to be tested is determined to be failed, and the current path between the component to be tested and the common pad is disconnected through the protection unit of the test circuit, and the test voltage is stopped from being applied to the branch pad of the test circuit where the component to be tested is located.

[0008] In order to solve the above problems, the present invention provides a semiconductor testing method, comprising the following steps: providing a semiconductor test structure and multiple components to be tested, wherein the components to be tested have a first test end and a second test end, and the semiconductor test structure adopts the semiconductor test structure described in the present invention; applying a test voltage at each of the branch pads and applying a common voltage at the common pad to simultaneously perform dielectric layer reliability tests on the multiple components to be tested, and obtaining the current passing through each of the test circuits, wherein the test voltage is greater than the common voltage; when the current on the branch pad in a test circuit rises to a preset threshold current, it is determined that the component to be tested in the test circuit has failed, the current path between the component to be tested and the common pad is disconnected by the protection unit, and the application of the test voltage to the branch pads of the test circuit is stopped; when it is determined that the components to be tested in all test circuits have failed, the test is terminated.

[0009] The above technical solution connects multiple test circuits in parallel to a common pad and tests multiple components to be tested at the same time, so as to shorten the total test time and improve production efficiency; and sets a switching unit and a protection unit in each of the test circuits to avoid affecting other test circuits when the component to be tested fails.

[0010] It should be understood that the above general description and the following detailed description are exemplary and explanatory only and do not limit the present invention. Technologies, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be considered part of the specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the following briefly introduces the drawings required for describing the specific embodiments. Obviously, the drawings described below are only some specific embodiments of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0012] Figure 1 Shown is a structural schematic diagram of a dielectric layer test structure in the prior art.

[0013] Figure 2 FIG. 1 is a schematic structural diagram of an embodiment of a semiconductor test structure according to the present invention.

[0014] Figure 3 FIG. 1 is an equivalent circuit diagram of a semiconductor test structure according to an embodiment of the present invention in a test state.

[0015] Figure 4 FIG. 1 is an equivalent circuit diagram of a semiconductor test structure according to an embodiment of the present invention in a breakdown state.

[0016] Figure 5 FIG. 1 is a schematic structural diagram of another embodiment of the semiconductor test structure of the present invention.

[0017] Figure 6 FIG. 1 is a schematic structural diagram of another embodiment of the semiconductor test structure of the present invention.

[0018] Figure 7 FIG. 1 is a schematic diagram of the structure of a test system according to an embodiment of the present invention.

[0019] Figure 8 FIG. 1 is a flowchart of the steps of an embodiment of a semiconductor testing method according to the present invention. DETAILED DESCRIPTION

[0020] The specific implementation methods of the semiconductor test structure, test method, and test system provided by the present invention are described in detail below with reference to the accompanying drawings.

[0021] Please also refer to Figures 2 to 4 ,in, Figure 2 FIG2 is a schematic structural diagram of an embodiment of a semiconductor test structure according to the present invention; Figure 3 FIG2 is an equivalent circuit diagram of an embodiment of the semiconductor test structure of the present invention in a test state; Figure 4 FIG. 1 is an equivalent circuit diagram of a semiconductor test structure according to an embodiment of the present invention in a breakdown state.

[0022] like Figure 2 As shown, the semiconductor test structure includes a common pad 20 and multiple test circuits. The common pad 20 is used to receive a common voltage V0. The multiple test circuits are electrically connected to the common pad 20. Each test circuit is used to perform a dielectric layer reliability test on a component under test 21. Each test circuit includes a branch pad 22, a switch unit 23, and a protection unit 24.

[0023] The branch pad 22 is electrically connected to the first test terminal T1 of the component under test 21 and is used to receive a test voltage VT, where the test voltage VT is greater than the common voltage V0.

[0024] The control end K0 of the switch unit 23 is electrically connected to the branch pad 22, the first end K1 thereof is electrically connected to the second test end T2 of the component under test 21, and the second end K2 thereof is electrically connected to the common pad 20. The switch unit 23 is turned on in response to the breakdown of the component under test 21 to raise the current on the branch pad 22 to a preset threshold current to determine that the component under test 21 has failed.

[0025] The first terminal T3 of the protection unit 24 is electrically connected to the second test terminal T2 of the component under test, and the second terminal T4 thereof is connected to the common pad 20, so as to disconnect the current path between the component under test 21 and the common pad 20 when the component under test 21 breaks down.

[0026] In addition, the semiconductor test structure is further configured to stop applying the test voltage VT to the branch pad 22 of the test circuit where the component under test 21 is located when it is determined that the component under test 21 has failed.

[0027] The above technical solution connects multiple test circuits in parallel to a common pad 20 and tests multiple components under test 21 at the same time, so as to shorten the total test time and improve production efficiency; and sets a switch unit 23 and a protection unit 24 in each of the test circuits to avoid affecting other test circuits when the component under test 21 fails.

[0028] In some embodiments, the switch unit 23 includes a field effect transistor. The gate G of the field effect transistor serves as the control terminal K0 of the switch unit 23, the drain D of the field effect transistor serves as the first terminal K1 of the switch unit 23, and the source S and substrate B are short-circuited to serve as the second terminal K2 of the switch unit 23.

[0029] In some embodiments, the preset threshold current is a saturation current when the field effect transistor is turned on.

[0030] In some embodiments, the protection unit 24 includes a fuse. When the component under test 21 breaks down, a sudden large current blows the fuse, thereby disconnecting the current path between the component under test 21 and the common pad 20 .

[0031] like Figure 2 and Figure 3 As shown, in a normal test state, the branch pad 22, the component under test 21, the protection unit 24, and the common pad 20 form a first path. A first current I1 flows through the first path, and the first current I1 is less than the preset threshold current. At this time, the field effect transistor is not turned on and acts as a capacitor (indicated by reference numeral 30) in the circuit.

[0032] like Figure 4 As shown, when a component under test 21 breaks down, the first current I1 in the test circuit increases, causing the protection unit 24 in the test circuit to fuse and disconnect the first path. At the same time, due to the breakdown of the component under test 21, the voltage at the first terminal K1 of the switch unit 23 in the test circuit rises to the test voltage VT, the switch unit 23 turns on, and the branch pad 22, the switch unit 23, and the common pad 20 in the test circuit form a second path. A second current I2 flows through the second path, and the second current I2 is equal to the preset threshold current, meeting the machine identification requirement. The component under test 21 is determined to be failed, and the pressure on the branch pad 22 in the test circuit is stopped.

[0033] Due to the presence of the protection unit 24, when a component under test 21 is broken down and the switch unit 23 in the test circuit is turned on, the second current I2 is limited and does not affect the current of other test circuits. When the protection unit 24 is disconnected, the second end K2 of the switch unit 23 in the other test circuits maintains the same potential as the second end K2 of the switch unit 23 in the test circuit where the component under test 21 is broken down, and the common voltage V0, and the current of other test circuits is not affected. If the protection unit 24 is not provided, the second end K2 of the switch unit 23 in the other test circuits maintains the same potential as the second end K2 of the switch unit 23 in the test circuit where the component under test 21 is broken down, that is, the test voltage VT, causing the switch unit 23 in the other test circuit to be turned on, affecting the test of the test circuit in which it is located.

[0034] If only the protection unit 24 is provided without the switch unit 23 , when a component under test 21 breaks down, the protection unit 24 in the test circuit will fuse, and the current at the branch pad 22 will drop instantaneously, and the test machine will be unable to determine the failure.

[0035] The switch unit 23 is further used for filtering in the test circuit, which is equivalent to a capacitor, to prevent the instantaneous current change when a component under test 21 breaks down from affecting the current in other test circuits.

[0036] In addition, since different components under test 21 are located in independent test circuits, different test circuits can be designed according to different types of components under test 21 , and the scope of application is wide.

[0037] See also Figure 5 , which is a structural diagram of another embodiment of the semiconductor test structure of the present invention. Figure 2 The difference from the illustrated embodiment is that the test circuit of this embodiment further includes a voltage-dividing and current-limiting unit 25, which is connected in series between the branch pad 22 and the switch unit 23 and is used to divide the voltage of the switch unit 23 and limit the current of the switch unit 23 when the switch unit 23 is turned on. The voltage-dividing and current-limiting unit 25 is also used to prevent the switch unit 23 from failing during the pressurization process, thereby protecting the switch unit 23.

[0038] In some embodiments, the voltage-dividing and current-limiting unit 25 is a capacitor.

[0039] See also Figure 6 , which is a structural diagram of another embodiment of the semiconductor test structure of the present invention. Figure 2The difference from the embodiment shown is that the test circuit of this embodiment further includes a filtering unit 26 , which is connected in series between the branch pad 22 and the common pad 20 and in parallel with the switch unit 23 to achieve a better filtering effect.

[0040] In some embodiments, the filter unit 26 is a capacitor. In some embodiments, a voltage dividing and current limiting unit 25 (such as Figure 5 As shown), the voltage dividing and current limiting unit 25 is connected in series between the branch pad 22 and the switch unit 23.

[0041] Based on the same inventive concept, the present invention also provides a testing system.

[0042] See also Figure 7 , which is a schematic diagram of the architecture of an embodiment of the test system of the present invention. Figure 7 As shown, the test system of this embodiment includes: a plurality of components under test 101 and a semiconductor test structure 102. The plurality of components under test 101 are respectively located in a plurality of test circuits of the semiconductor test structure 102, and each component under test 101 has a first test terminal and a second test terminal. The semiconductor test structure 102 adopts the present invention. Figures 2 to 6 The semiconductor test structure is used to perform dielectric layer reliability tests on multiple components under test 101 at the same time, and in response to the breakdown of the component under test 101 electrically connected to the test circuit, the switch unit of a test circuit is turned on, the current on the branch pad of the test circuit is raised to a preset threshold current, the component under test 101 is determined to be failed, and the current path between the component under test 101 and the common pad is disconnected through the protection unit of the test circuit, and the test voltage is stopped from being applied to the branch pad of the test circuit where the component under test 101 is located.

[0043] The above technical solution connects multiple test circuits in parallel to a common pad and tests multiple components under test 101 at the same time, so as to shorten the total test time and improve production efficiency; and sets a switching unit and a protection unit in each of the test circuits to avoid affecting other test circuits when the component under test 101 fails.

[0044] Based on the same inventive concept, the present invention also provides a semiconductor testing method.

[0045] Figure 8The figure shows a step flow chart of an embodiment of the semiconductor testing method described in the present invention, which includes the following steps: step S81, providing a semiconductor test structure and multiple components to be tested, wherein the components to be tested have a first test end and a second test end, and the semiconductor test structure adopts the semiconductor test structure described in the present invention; step S82, applying a test voltage at each of the branch pads and applying a common voltage at the common pad to simultaneously perform dielectric layer reliability tests on multiple components to be tested, and obtaining the current passing through each of the test circuits, wherein the test voltage is greater than the common voltage; step S83, when the current on the branch pad in a test circuit rises to a preset threshold current, it is determined that the component to be tested in the test circuit has failed, the current path between the component to be tested and the common pad is disconnected by the protection unit, and the application of the test voltage to the branch pads of the test circuit is stopped; step S84, when it is determined that the components to be tested in all test circuits have failed, the test is ended.

[0046] Please refer to Figures 2 to 6 And step S81, providing a semiconductor test structure and a plurality of components under test 21, wherein the components under test 21 have a first test terminal T1 and a second test terminal T2, and the semiconductor test structure adopts the present invention Figures 2 to 6 The semiconductor test structure.

[0047] Please refer to Figure 3 And step S82, applying a test voltage VT to each of the branch pads 22 and a common voltage V0 to the common pad 20, so as to simultaneously perform dielectric layer reliability testing on multiple components under test 21, and obtain the current passing through each of the test circuits, wherein the test voltage VT is greater than the common voltage V0. In this embodiment, under normal test conditions, the branch pads 22, the components under test 21, the protection unit 24, and the common pad 20 form a first path, through which a first current I1 passes, and the first current I1 is less than the preset threshold current. At this time, the field effect transistor is not turned on and is equivalent to a capacitor in the circuit.

[0048] Please refer to Figure 4And step S83, when the current on the branch pad 22 in a test circuit rises to a preset threshold current, it is determined that the component under test 21 of the test circuit has failed, and the protection unit 24 disconnects the current path between the component under test 21 and the common pad 20, and stops applying the test voltage VT to the branch pad 22 of the test circuit. In this embodiment, when a component under test 21 is broken down, the first current I1 increases, causing the protection unit 24 to disconnect the first path. At the same time, due to the breakdown of the component under test 21, the voltage at the first end K1 of the switch unit 23 rises to the test voltage VT, the switch unit 23 is turned on, and the branch pad 22, the switch unit 23, and the common pad 20 form a second path. The second current I2 passes through the second path, and the second current I2 is equal to the preset threshold current, meeting the machine identification requirement, and the component under test 21 is determined to be failed, and the pressure on the branch pad 22 is stopped.

[0049] Please refer to step S84 , when it is determined that all the components under test 21 in the test circuits have failed, the test is terminated.

[0050] The above technical solution connects multiple test circuits in parallel to a common pad 20 and tests multiple components under test 21 at the same time, so as to shorten the total test time and improve production efficiency; and sets a switch unit 23 and a protection unit 24 in each of the test circuits to avoid affecting other test circuits when the component under test 21 fails.

[0051] It should be noted that references in the specification to "one embodiment," "an embodiment," "an exemplary embodiment," "some embodiments," etc. indicate that the described embodiment may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. In addition, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, it is within the knowledge of those skilled in the relevant art to implement such feature, structure, or characteristic in conjunction with other embodiments, whether or not explicitly described.

[0052] Typically, a term can be understood at least in part from its usage in the context. For example, the term "one or more" as used herein depends at least in part on the context and can be used to describe any feature, structure or characteristic in a singular sense, or can be used to describe a feature, structure or combination of features in a plural sense. Similarly, depending at least in part on the context, terms such as "one", "a" or "the" can also be understood to express singular usage or to express plural usage. In addition, the term "based on" can be understood as not necessarily intended to express an exclusive set of factors, but can alternatively, also depending at least in part on the context, allow for the presence of other factors that are not necessarily explicitly described. It should also be noted in this specification that "connected / coupled" refers not only to the direct coupling of one component to another component, but also to the indirect coupling of one component to another component through an intermediate component.

[0053] It should be noted that the terms "including" and "having" and their variations involved in the documents 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 otherwise, it should be understood that the data used in this way can be interchanged under appropriate circumstances. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other unless there is a conflict. In addition, in the above description, the description of well-known components and technologies has been omitted to avoid unnecessary confusion of the concepts 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.

[0054] The above description 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 principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A semiconductor test structure, characterized in that: include: a common pad for receiving a common voltage; A plurality of test circuits are electrically connected to the common pad, each of the test circuits is used to perform a dielectric layer reliability test on a component under test, and each of the test circuits includes: a branch pad, electrically connected to the first test terminal of the component to be tested, and configured to receive a test voltage, wherein the test voltage is greater than the common voltage; a switch unit, wherein a control end of the switch unit is electrically connected to the branch pad, a first end of the switch unit is electrically connected to the second test end of the component under test, and a second end of the switch unit is electrically connected to the common pad, and the switch unit is turned on in response to a breakdown of the component under test to increase the current on the branch pad to a preset threshold current to determine that the component under test has failed; a protection unit, wherein a first end of the protection unit is electrically connected to the second test end of the component under test, and a second end of the protection unit is connected to the common pad, and is configured to disconnect the current path between the component under test and the common pad when a breakdown occurs in the component under test; When it is determined that the component under test fails, application of the test voltage to the branch pad of the test circuit where the component under test is located is stopped.

2. The semiconductor test structure according to claim 1, wherein: The switch unit includes a field effect transistor, the gate of the field effect transistor serves as the control terminal of the switch unit, the drain of the field effect transistor serves as the first terminal of the switch unit, and the source and substrate of the field effect transistor are short-circuited to serve as the second terminal of the switch unit.

3. The semiconductor test structure according to claim 2, wherein: The preset threshold current is the saturation current when the field effect transistor is turned on.

4. The semiconductor test structure according to claim 1, wherein: The protection unit includes a fuse.

5. The semiconductor test structure according to claim 1, wherein: The test circuit further includes a voltage-dividing and current-limiting unit, which is connected in series between the branch pad and the switch unit and is used to divide the voltage of the switch unit and limit the current of the switch unit when the switch unit is turned on.

6. The semiconductor test structure according to claim 5, wherein: The voltage dividing and current limiting unit adopts a capacitor.

7. The semiconductor test structure according to claim 1, wherein: The test circuit further includes a filter unit, which is connected in series between the branch pad and the common pad and in parallel with the switch unit.

8. The semiconductor test structure according to claim 7, wherein: The filtering unit adopts a capacitor.

9. A testing system, characterized in that: include: A plurality of components under test, each of the components under test having a first test end and a second test end; A semiconductor test structure, wherein the semiconductor test structure adopts the semiconductor test structure according to any one of claims 1 to 8, and is used to simultaneously perform dielectric layer reliability tests on multiple components to be tested, and a switch unit in a test circuit is turned on in response to a breakdown of a component to be tested electrically connected to the test circuit, raising the current on the branch pad of the test circuit to a preset threshold current, determining that the component to be tested has failed, and disconnecting the current path between the component to be tested and the common pad through a protection unit of the test circuit, and stopping applying the test voltage to the branch pad of the test circuit where the component to be tested is located.

10. A semiconductor testing method, characterized in that: The steps include: A semiconductor test structure and a plurality of components to be tested are provided, wherein the components to be tested have a first test terminal and a second test terminal, and the semiconductor test structure adopts the semiconductor test structure according to any one of claims 1 to 8; Applying a test voltage to each of the branch pads and a common voltage to the common pad to simultaneously perform dielectric layer reliability testing on multiple components under test and obtain a current passing through each of the test circuits, wherein the test voltage is greater than the common voltage; When the current on the branch pad in a test circuit rises to a preset threshold current, it is determined that the component under test of the test circuit has failed, and the current path between the component under test and the common pad is disconnected by the protection unit, and the test voltage is stopped from being applied to the branch pad of the test circuit; When it is determined that all components under test in the test circuits have failed, the test is terminated.

Images