Test pattern and method for contact resistance

Abstract

The embodiment of the present disclosure provides a test layout of contact resistance and a test method; wherein the test layout comprises: an active layer, the active layer comprises a plurality of active region patterns; a first contact plug layer, the first contact plug layer comprises a plurality of repeatedly arranged first contact plug patterns; a second contact plug layer, the second contact plug layer comprises a plurality of repeatedly arranged second contact plug patterns; a first metal layer and a second metal layer; the active layer, the first contact plug layer and the first metal layer constitute a first layout, the first layout is used to form a first contact plug structure; the active layer, the first contact plug layer, the first metal layer, the second contact plug layer and the second metal layer constitute a second layout, the second layout is used to form a parallel first contact plug structure and a second contact plug structure.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor technology, and includes, but is not limited to, a test layout and test method for contact resistance. Background Technology

[0002] In related technologies, there are various ways to measure the contact resistance of contact holes in semiconductor devices, but these methods can only measure the contact resistance of a single type of contact hole. In this technology, multiple contact holes are set up during measurement, and the measured test results are averaged to obtain the contact resistance value of each contact hole.

[0003] However, the contact resistance value of the contact hole measured by the measurement method in the related technology is affected by many external factors, and there is a large error between the actual contact resistance value of the contact hole and the measured resistance value. Summary of the Invention

[0004] In view of this, embodiments of the present disclosure provide a test layout and test method for contact resistance.

[0005] In a first aspect, embodiments of this disclosure provide a test layout for contact resistance, the test layout comprising:

[0006] An active layer, wherein the active layer comprises a plurality of active region patterns;

[0007] A first contact embolization layer, the first contact embolization layer comprising a plurality of repeating first contact embolization patterns;

[0008] The second contact embolization layer includes a plurality of repeating second contact embolization patterns;

[0009] First metal layer and second metal layer;

[0010] The active layer, the first contact plug layer, and the first metal layer constitute a first layout, which is used to form the first contact plug structure.

[0011] The active layer, the first contact plug layer, the first metal layer, the second contact plug layer, and the second metal layer constitute a second layout, which is used to form a parallel first contact plug structure and a second contact plug structure.

[0012] In some embodiments, the first metal layer includes a plurality of first metal line patterns;

[0013] The active area pattern includes at least two first contact plug patterns, each of which is located in the overlapping area of ​​the active area pattern and the first metal wire pattern, forming the first layout.

[0014] In some embodiments, the second metal layer includes a plurality of second metal line patterns;

[0015] The active area pattern includes at least two first contact plug patterns and at least two second contact plug patterns. Each second contact plug pattern coincides with the first contact plug pattern and is located in the overlapping area of ​​the active area pattern and the first metal wire pattern. The second metal wire pattern covers at least two second contact plug patterns located on the same active area pattern, forming the second layout.

[0016] In some embodiments, the first layout and the second layout share a plurality of the active region patterns.

[0017] In some embodiments, the active region pattern is arranged in an S-shaped linear chain; or,

[0018] The active region pattern is arranged in an array along a first direction and / or a second direction; wherein the first direction and the second direction are perpendicular to each other.

[0019] In some embodiments, the first metal wire pattern includes at least one first U-shaped pattern and at least one second U-shaped pattern.

[0020] In some embodiments, the sum of the lengths of the first metal wire patterns in the first layout is equal to the sum of the lengths of the first metal wire patterns in the second layout.

[0021] In some embodiments, the first pattern further includes two first contact pad patterns; the second pattern further includes two second contact pad patterns.

[0022] In some embodiments, the test layout further includes a gate layer, the gate layer comprising a plurality of gate patterns;

[0023] The gate pattern is located on the active region pattern, and the first contact plug structure and the second contact plug structure are symmetrically distributed about the gate pattern.

[0024] Secondly, embodiments of this disclosure provide a method for testing contact resistance, the method comprising:

[0025] A test structure is provided, the test structure including an active layer, a first contact plug layer, a first metal layer, a second contact plug layer and a second metal layer;

[0026] Wherein, the active layer, the first contact plug layer, and the first metal layer constitute a first test structure, the first test structure including a first contact plug structure; the active layer, the first contact plug layer, the first metal layer, the second contact plug layer, and the second metal layer constitute a second test structure, the second test structure including a first contact plug structure and a second contact plug structure connected in parallel.

[0027] Test voltages are applied to the first test structure and the second test structure to obtain the first contact resistance of the first contact plug structure and the second contact resistance of the second contact plug structure.

[0028] In some embodiments, the first test structure includes at least two first contact embolization structures;

[0029] In the first test structure, the active layer is connected in series with the first metal layer through the first contact plug layer.

[0030] In some embodiments, the second test structure includes at least two first contact embolization structures and at least two second contact embolization structures;

[0031] In the second test structure, the active layer is connected in series with the first metal layer through the first contact plug layer; the first metal layer is connected in series with the second metal layer through the second contact plug layer.

[0032] The active layer and the second metal layer are connected in parallel through the first contact plug layer and the second contact plug layer.

[0033] In some embodiments, the first test structure and the second test structure share the active layer.

[0034] In some embodiments, applying a test voltage to the first test structure and the second test structure to obtain the first contact resistance of the first contact plug structure and the second contact plug structure includes:

[0035] The test voltage is applied to the first test structure to obtain the first contact resistance of the first contact plug structure.

[0036] The test voltage is applied to the second test structure to obtain the second contact resistance of the second contact plug structure.

[0037] In some embodiments, the structure to be tested further includes two first contact pads, which are connected to the first test structure through the first metal layer;

[0038] The step of applying the test voltage to the first test structure to obtain the first contact resistance of the first contact plug structure includes:

[0039] The first current device and the first voltage device are respectively connected through the two first contact pads;

[0040] After the test voltage is applied to the first test structure by the first voltage device, the first current of the first test structure is detected by the first current device.

[0041] The first total resistance of the first test structure is obtained based on the test voltage and the first current.

[0042] The first contact resistance of the first contact plug structure is obtained based on the first total resistance and the number of the first contact plug structures.

[0043] In some embodiments, the structure to be tested further includes two second contact pads, which are connected to the second test structure through the first metal layer;

[0044] The step of applying the test voltage to the second test structure to obtain the second contact resistance of the second contact plug structure includes:

[0045] The second current device and the second voltage device are respectively connected through the two second contact pads;

[0046] After the test voltage is applied to the second test structure by the second voltage device, the second current of the second test structure is detected by the second current device.

[0047] The second total resistance of the second test structure is obtained based on the test voltage and the second current.

[0048] The second contact resistance of the second contact plug structure is determined based on the second total resistance, the number of the first contact plug structures, the number of the second contact plug structures, and the first contact resistance.

[0049] According to the contact resistance test layout and test method provided in this disclosure, a first layout and a second layout are formed by an active layer, a first contact plug layer, a first metal layer, a second contact plug layer, and a second metal layer. Based on the first layout and the second layout, the contact resistance of the first contact plug structure in the first layout and the second contact plug structure in the second layout can be measured respectively. Moreover, the contact resistance of the first contact plug structure and the second contact plug structure are measured under the same environment in this disclosure, eliminating the interference of irrelevant factors. This makes the contact resistance measured by this disclosure closer to the contact resistance value of the transistor in the real working environment, thus improving the accuracy of the measurement results. Attached Figure Description

[0050] In the accompanying drawings (which are not necessarily drawn to scale), similar reference numerals may describe similar parts in different views. Similar reference numerals with different letter suffixes may indicate different examples of similar parts. The drawings illustrate, by way of example and not limitation, the various embodiments discussed herein.

[0051] Figures 1a to 1g This is a schematic diagram of the test layout structure of the contact resistance provided in an embodiment of this disclosure;

[0052] Figure 2 This is a schematic flowchart of the contact resistance testing method provided in the embodiments of this disclosure;

[0053] Figures 3a to 3g This is a partial structural schematic diagram corresponding to the contact resistance testing method provided in the embodiments of this disclosure;

[0054] Figure label:

[0055] 101-Active layer; 101-1-Active region pattern; 102-First contact plug layer; 103-First metal layer; 103-1-First metal wire pattern; 104-Second contact plug layer; 105-Second metal layer; 105-1-Second metal wire pattern; 106-First contact plug pattern; 107-Second contact plug pattern; 108-First U-shaped pattern; 109-Second U-shaped pattern; 110-First straight line pattern; 111 - Second straight line pattern; 112 - First contact pad pattern; 113 - Second contact pad pattern; 114 - Gate pattern; 10 - First layout; 20 - Second layout; 30 - First test structure; 40 - Second test structure; 301 - Active layer; 302 - First metal layer; 303 - Second metal layer; 304 - First contact plug structure; 305 - Second contact plug structure; 306 - First contact pad; 307 - Second contact pad. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the specific technical solutions of this disclosure will be further described in detail below with reference to the accompanying drawings of the embodiments of this disclosure. The following embodiments are used to illustrate this disclosure, but are not intended to limit the scope of this disclosure.

[0057] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of this disclosure. However, it will be apparent to those skilled in the art that this disclosure may be practiced without one or more of these details. In other instances, to avoid confusion with this disclosure, certain technical features well-known in the art have not been described; that is, not all features of actual embodiments are described herein, nor are well-known functions and structures described in detail.

[0058] In the accompanying drawings, for clarity, the dimensions of layers, areas, and elements, as well as their relative dimensions, may be exaggerated. The same reference numerals denote the same elements throughout.

[0059] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this disclosure, the first element, component, area, layer, or portion discussed below may be referred to as a second element, component, area, layer, or portion. And the discussion of a second element, component, area, layer, or portion does not imply that the first element, component, area, layer, or portion necessarily exists in this disclosure.

[0060] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below,” “under,” or “below” other elements or features will be oriented “above” other elements or features. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.

[0061] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprise” and / or “comprising,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0062] Based on the problems existing in related technologies, this disclosure embodiment distributes a first layout and a second layout on both sides of a complementary metal oxide semiconductor (CMOS). The metal resistance is negligible. The first layout includes a first contact plug structure (PC), and the second layout includes a first contact plug structure and a second contact plug structure (CT) connected in parallel. The resistance of the first contact plug structure (PC) is obtained based on the same structure and operating environment as the transistor. The resistance value of the second contact plug structure (CT) is obtained through the series and parallel operation rules of the resistance. The measurement environment of this disclosure embodiment is closer to the real working environment, so this disclosure embodiment can obtain a more accurate contact resistance value.

[0063] In this embodiment of the disclosure, Figures 1a to 1g This is a schematic diagram of the test layout structure of the contact resistance provided in an embodiment of this disclosure, as shown below. Figures 1a to 1cAs shown, the test layout structure for contact resistance includes: an active layer 101, a first contact plug layer 102, a first metal layer 103, a second contact plug layer 104, and a second metal layer 105; wherein, the active layer 101 includes several active region patterns 101-1; the first contact plug layer 102 includes multiple repeated first contact plug patterns 106; the second contact plug layer 104 includes multiple repeated second contact plug patterns 107; the first metal layer 103 and the second metal layer 105; the active layer 101, the first contact plug layer 102, and the first metal layer 103 constitute a first layout 10, which is used to form a first contact plug structure; the active layer 101, the first contact plug layer 102, the first metal layer 103, the second contact plug layer 104, and the second metal layer 105 constitute a second layout 20, which is used to form a parallel first contact plug structure and a second contact plug structure.

[0064] In some embodiments, the first metal layer 103 includes a plurality of first metal line patterns 103-1; the second metal layer 105 includes a plurality of second metal line patterns 105-1.

[0065] In this embodiment of the disclosure, the first direction is the X direction, the second direction is the Y direction, and the third direction is the Z direction. The first direction, the second direction, and the third direction are all perpendicular to each other. Figure 1b and Figure 1c They are Figure 1a A cross-sectional view of regions A and B along the Y direction.

[0066] It should be noted that, Figures 1a to 1c The areas not shown are all dielectric layers, for example Figure 1b In the first contact embolization layer 102, the area other than the first contact embolization pattern 106 is a dielectric layer. In order to make the layout structure in the accompanying drawings clear, some dielectric layers are not shown in the accompanying drawings of this embodiment.

[0067] In some embodiments, such as Figure 1a As shown, the active region pattern 101-1 can be arranged in an array along the first direction (i.e., the X direction) and / or the second direction (i.e., the Y direction).

[0068] In some embodiments, such as Figure 1d As shown, the active region pattern 101-1 can also be arranged in an S-shaped straight chain.

[0069] Please continue to refer to Figures 1a to 1dIn the test layout provided in this embodiment, each active area pattern 101-1 includes at least two first contact plug patterns 106. Each first contact plug pattern is located in the overlapping area of ​​the active area pattern 101-1 and the first metal wire pattern 103-1, forming a first layout 10 with a first S-shaped pattern.

[0070] In some embodiments, each active region pattern 101-1 further includes at least two first contact plug patterns 106 and at least two second contact plug patterns 107; in the Z direction, each second contact plug pattern 107 coincides with the first contact plug pattern 106 and is located in the overlapping area of ​​the active region pattern 101-1 and the first metal wire pattern 103-1, and the second metal wire pattern 105-1 covers at least two second contact plug patterns 107 located on the same active region pattern 101-1, forming a second layout 20.

[0071] In some embodiments, the first version 10 and the second version 20 share a plurality of active area patterns 101-1.

[0072] Based on the foregoing embodiments, please refer to Figure 1e ,like Figure 1e As shown, the first metal wire pattern 103-1 includes at least one first U-shaped pattern 108 and at least one second U-shaped pattern 109. The first pattern 10 includes at least one first U-shaped pattern 108 and a second U-shaped pattern 109, and the second pattern 20 includes at least one first U-shaped pattern 108 and a second U-shaped pattern 109. The length of the first U-shaped pattern 108 is a1, and the length of the second U-shaped pattern 109 is a2. The lengths of the first U-shaped patterns 108 and the second pattern 20 are the same. The lengths of the second U-shaped patterns 109 in the first pattern 10 and the second pattern 20 are the same.

[0073] In some embodiments, the first layout 10 and the second layout 20 further include a first straight line pattern 110 and a second straight line pattern 111, and the length of the first straight line pattern 110 in the first layout 10 is the same as the length of the first straight line pattern 110 in the second layout 20, and the length of the second straight line pattern 111 in the first layout 10 is the same as the length of the second straight line pattern 111 in the second layout 20, so that the lengths of each segment of the first metal wire pattern 103-1 in the first layout 10 and the second layout 20 are equal. Therefore, the total length of the first metal wire pattern 103-1 in the first layout 10 is equal to the total length of the first metal wire pattern 103-1 in the second layout 20. This ensures that when the layout structure provided in this embodiment of the present disclosure is used to measure contact resistance, the measurement results obtained by the first layout 10 and the second layout 20 will not have errors due to the different lengths of the first metal wire pattern 103-1 in the first layout 10 and the second layout 20, making the contact resistance value measured using the layout structure provided in this embodiment of the present disclosure more accurate.

[0074] In some embodiments, the first layout 10 further includes two first contact pad patterns 112, on which first contact pads are formed; the second layout 20 further includes two second contact pad patterns 113, on which second contact pads are formed.

[0075] The first pattern 10 has a first contact pad pattern 112 connected to each end, and the second pattern 20 has a second contact pad pattern 113 connected to each end. Figure 1f As shown.

[0076] In this embodiment, the first and second contact pads are used to connect measuring instruments or power sources, such as current measuring instruments or power supplies that apply voltage. The first and second contact pads are used to detect current and voltage data in the first pattern 10 and the second pattern 20, respectively. Two first contact pad patterns 112 are connected to each side of the first pattern 10, and two second contact pad patterns 113 are connected to each side of the second pattern 20, respectively, to measure the current and voltage data in the first and second patterns 10 and 20. This allows the two sets of measured data to be mutually calibrated, resulting in more accurate detection results.

[0077] In some embodiments, please refer to Figure 1g The test layout also includes a gate layer located on the active layer. The gate layer includes a plurality of gate patterns 114. The gate patterns 114 extend along a second direction (i.e., the Y direction), and two adjacent gate patterns 114 are arranged in parallel in a first direction (i.e., the X direction). The first contact plug pattern 106 and the second contact plug pattern 107 are located on both sides of the gate pattern 114, that is, the first layout 10 and the second layout 20 are located on both sides of the gate pattern 114.

[0078] In some embodiments, the gate pattern 114 is located on the active region pattern 101-1, and the first contact plug pattern 106 and the second contact plug pattern 107 are symmetrically distributed about the gate pattern 114.

[0079] The layout structure provided in this embodiment has a first layout and a second layout located on both sides of the gate pattern. When measuring contact resistance using the first layout and the second layout, the environment of a real transistor can be simulated, making the contact resistance measured in this embodiment closer to the contact resistance when the transistor is running, thus improving the accuracy of the measurement results.

[0080] The layout structure provided in this disclosure allows for the measurement of the contact resistance of the first contact plug structure in the first layout and the second contact plug structure in the second layout, based on the first layout and the second layout. Furthermore, this disclosure involves measuring the contact resistance of the first and second contact plug structures under the same environment, eliminating interference from irrelevant factors. This makes the contact resistance measured in this disclosure closer to the contact resistance value of the transistor in a real working environment, thereby improving the accuracy of the measurement results.

[0081] Based on the above test layout, this disclosure further provides a method for testing contact resistance, such as... Figure 2 As shown, Figure 2 This is a schematic flowchart of a contact resistance testing method provided in this embodiment of the present disclosure. The contact resistance testing method provided in this embodiment of the present disclosure is implemented through the following steps:

[0082] Step S201: Provide a structure to be tested, which includes an active layer, a first contact plug layer, a first metal layer, a second contact plug layer, and a second metal layer; wherein, the active layer, the first contact plug layer, and the first metal layer constitute a first test structure, which includes a first contact plug structure; the active layer, the first contact plug layer, the first metal layer, the second contact plug layer, and the second metal layer constitute a second test structure, which includes a first contact plug structure and a second contact plug structure connected in parallel.

[0083] Step S202: Apply a test voltage to the first test structure and the second test structure to obtain the first contact resistance of the first contact plug structure and the second contact resistance of the second contact plug structure.

[0084] Please refer to the following. Figures 3a to 3g The method for testing contact resistance provided in the embodiments of this disclosure will be described in detail.

[0085] like Figure 3a As shown, the structure to be tested includes an active layer 301, a first contact plug layer (not shown in the figure), a first metal layer 302, a second contact plug layer (not shown in the figure), and a second metal layer 303; wherein, the active layer 301, the first contact plug layer, and the first metal layer 302 are used to form a first test structure 30, the first test structure 30 including a first contact plug structure 304; the active layer 301, the first contact plug layer, the first metal layer 302, the second contact plug layer, and the second metal layer 303 are used to form a second test structure 40, the second test structure 40 including a first contact plug structure 304 and a second contact plug structure 305 connected in parallel.

[0086] Figure 3b and Figure 3d They are Figure 3a A cross-sectional view of regions C and D along the Y direction. Figure 3c yes Figure 3b Simplified circuit diagram, Figure 3e yes Figure 3d A simplified circuit diagram. (Example) Figure 3b As shown, the first test structure 30 includes at least two first contact plug structures 304, which are connected in series. The active layer 301 is connected in series with the first metal layer 302 through the first contact plug structures 304 in the first contact plug layer.

[0087] In some embodiments, the series relationship between the active layer 301, the first metal layer 302, and the first contact plug structure 304 is as follows: Figure 3c As shown, it should be noted that Figure 3c Only one example of a series structure on an active region pattern is given, which is also connected to other structures on both sides.

[0088] In some embodiments, such as Figure 3d As shown, the second test structure 40 includes at least two first contact plug structures 304 and at least two second contact plug structures 305. The two second contact plug structures 305 are connected in series, and the first contact plug structures 304 and the second contact plug structures 305 are connected in parallel. The active layer 301 is connected in series with the first metal layer 302 through the first contact plug structures 304 in the first contact plug layer. The first metal layer 302 is connected in series with the second metal layer 303 through the second contact plug structures 305 in the second contact plug layer. The active layer 301 and the second metal layer 303 are connected in parallel through the first contact plug structures 304 in the first contact plug layer and the second contact plug structures 305 in the second contact plug layer.

[0089] In some embodiments, the series-parallel connections between the active layer 301, the first metal layer 302, the first contact plug structure 304, the second metal layer 303, and the second contact plug structure 305 are as follows: Figure 3e As shown, it should be noted that Figure 3e The circuit structure on an active region pattern is given only as an example, and the circuit structure is connected to other structures on both sides.

[0090] In some embodiments, the first test structure 30 and the second test structure 40 share the active layer 301.

[0091] In some embodiments, step S202 can be implemented by the following steps:

[0092] Step S2021: Apply a test voltage to the first test structure to obtain the first contact resistance of the first contact plug structure.

[0093] In some embodiments, the structure to be tested further includes a first contact pad 306, which is connected to the first test structure 30 via a first metal layer 302, such as... Figure 3f As shown, applying a test voltage to the first test structure can mean connecting a power supply device capable of applying voltage to the first contact pad 306, and applying voltage to the first contact pad 306 through the power supply device, i.e., applying voltage to the first test structure 30. In this embodiment, a first contact pad 306 can be connected to both ends of the first test structure 30. One end of the first contact pad 306 is connected to the power supply device, and the other end of the first contact pad 306 is connected to a detection device such as a current detection instrument, for detecting data such as the current after applying voltage to the first test structure 30.

[0094] In some embodiments, the first test structure 30 includes at least two first contact plug structures 304.

[0095] The contact resistance of the first contact plug structure 304 connecting the active region 301 and the first metal layer 302 in this embodiment of the disclosure can be detected by the following steps:

[0096] Step S1: Connect the first current device and the first voltage device through two first contact pads respectively.

[0097] In this embodiment of the disclosure, a current detection device such as a current meter is connected to the first contact pad 306 at one end of the first test structure 30. In some embodiments, when detecting the contact resistance of the first contact plug structure 304, one end of the first test structure 30 is connected to a first voltage device to apply voltage, the other end is grounded, and current is detected at the grounded end through a first current device.

[0098] Step S2: After applying a test voltage to the first test structure through the first voltage device, the first current of the first test structure is detected by the first current device.

[0099] In some embodiments, a test voltage U is applied to the first test structure 30, and a first current I1 is detected by a first current device. In embodiments of this disclosure, the value of the test voltage U applied to the first test structure 30 can be 1 volt (V).

[0100] Step S3: Based on the test voltage and the first current, obtain the first total resistance of the first test structure.

[0101] In this embodiment, the resistance of the first metal layer 303 and the second metal layer 303 is negligible. The resistance of the active layer 301 is analogous to a sheet resistor, and is therefore negligible. The first total resistance R of the first test structure 30 is... 1总 Calculated using formula (1):

[0102]

[0103] Wherein, U is the test voltage applied by the first test structure 30; I1 is the current measured by the first test structure 30.

[0104] Step S4: Based on the first total resistance and the number of first contact plug structures, obtain the first contact resistance of the first contact plug structure.

[0105] In this embodiment of the disclosure, the first test structure 30 has a plurality of first contact plug structures 304 connected in series, and the contact resistance R1 of each first contact plug structure 304 is calculated by formula (2):

[0106]

[0107] Where x is the number of first contact plug structures 304 in the first test structure 30.

[0108] In this embodiment of the disclosure, the number of first contact plug structures 304 is sufficient to reduce the error caused by the failure of some first contact plug structures 304, so that the contact resistance value of the obtained first contact plug structure 304 is more accurate.

[0109] Step S2022: Apply a test voltage to the second test structure to obtain the second contact resistance of the second contact plug structure.

[0110] In some embodiments, the structure to be tested further includes a second contact pad 307, which is connected to the second test structure 40 via a first metal layer 302, such as... Figure 3g As shown, applying a test voltage to the second test structure 40 can mean connecting a power supply device capable of applying voltage to the second contact pad 307, and then applying voltage to the second contact pad 307 through the power supply device, i.e., applying voltage to the second test structure 40. In this embodiment, the second contact pad 307 can be connected to both ends of the second test structure 40. One end of the second contact pad 307 is connected to a power supply device, and the other end of the second contact pad 307 is connected to a detection device such as a current detection instrument, for detecting data such as the current after applying voltage to the second test structure 40.

[0111] In some embodiments, the second test structure 40 includes at least two second contact plug structures 305.

[0112] The contact resistance of the second contact plug structure 305 connecting the first metal layer 302 and the second metal layer 303 in this embodiment of the disclosure can be detected by the following steps:

[0113] Step S10: Connect the second current device and the second voltage device through the two second contact pads respectively.

[0114] In this embodiment of the disclosure, when detecting the contact resistance of the second contact plug structure 305, one end of the second test structure 40 is connected to a second voltage device to apply voltage, the other end is grounded, and current is detected through a second current device at the grounded end.

[0115] Step S20: After applying a test voltage to the second test structure through the second voltage device, the second current of the second test structure is detected by the second current device.

[0116] In the embodiments disclosed herein, such as Figure 3g As shown, the second test structure 40 includes multiple parallel lines as shown in D. In this embodiment of the present disclosure, the total resistance of each parallel line can be measured, and the contact resistance of the second contact plug structure 305 can be calculated based on the contact resistance of the first contact plug structure 304 measured in the previous embodiment.

[0117] In this embodiment of the disclosure, the test voltage U applied to the second test structure 40 can be the same as the test voltage U applied to the first test structure 30, both being 1V, and the second current of the second test structure 40 is detected by the second current device as I2.

[0118] Step S30: Obtain the second total resistance of the second test structure based on the test voltage and the second current.

[0119] In this embodiment of the disclosure, the second total resistance R of the second test structure 40 2总 The calculation can be performed using the following formula (3):

[0120]

[0121] Wherein, I2 is the second current of the second test structure 40 measured in this embodiment of the present disclosure.

[0122] Step S40: Determine the second contact resistance of the second contact plug structure based on the second total resistance, the number of first contact plug structures, the number of second contact plug structures, and the first contact resistance.

[0123] In this embodiment of the disclosure, each parallel line as shown in D is connected in series to form a second test structure 40. Therefore, the parallel resistance R of each parallel line is... 并 The calculation can be performed using the following formula (4):

[0124]

[0125] Where y is the number of parallel circuits as shown in D in the second test structure 40.

[0126] In this embodiment of the disclosure, each parallel line consists of two series lines, such as... Figure 3c As shown, one series circuit includes two first contact plug structures 304 and an active layer 301, and the other series circuit includes two second contact plug structures 305 and a second metal layer 303. The resistance of the active layer 301 and the second metal layer 303 is negligible. Therefore, the contact resistance R2 of each second contact plug structure 305 can be calculated by the following formula (5):

[0127]

[0128] The contact resistance testing method provided in this embodiment places the first test structure 30 and the second test structure 40 in the same transistor operating environment, reducing interference from the external environment and making the measured value closer to the true value. Furthermore, when calculating the contact resistance of the second contact plug structure, this embodiment is based on the contact resistance of the first contact plug structure in the same environment, making the contact resistance result of the second contact plug structure more realistic and accurate.

[0129] In the several embodiments provided in this disclosure, it should be understood that the disclosed devices and methods can be implemented in a non-target manner. The device embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components may be combined, or integrated into another system, or some features may be ignored or not executed. Furthermore, the various components shown or discussed may be coupled or directly coupled to each other.

[0130] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0131] The features disclosed in the several method or device embodiments provided in this disclosure can be arbitrarily combined without conflict to obtain new method or device embodiments.

[0132] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this invention should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A test layout for contact resistance, characterized in that, The test layout includes: An active layer, wherein the active layer comprises a plurality of active region patterns; A first contact embolization layer, the first contact embolization layer comprising a plurality of repeating first contact embolization patterns; The second contact embolization layer includes a plurality of repeating second contact embolization patterns; First metal layer and second metal layer; The active layer, the first contact plug layer, and the first metal layer constitute a first layout, which is used to form the first contact plug structure. The active layer, the first contact plug layer, the first metal layer, the second contact plug layer, and the second metal layer constitute a second layout, which is used to form a parallel first contact plug structure and a second contact plug structure. The first and second versions share several active region patterns.

2. The test layout according to claim 1, characterized in that, The first metal layer includes a plurality of first metal line patterns; The active area pattern includes at least two first contact plug patterns, each of which is located in the overlapping area of ​​the active area pattern and the first metal wire pattern, forming the first layout.

3. The test layout according to claim 2, characterized in that, The second metal layer includes a plurality of second metal line patterns; The active area pattern includes at least two first contact plug patterns and at least two second contact plug patterns. Each second contact plug pattern coincides with the first contact plug pattern and is located in the overlapping area of ​​the active area pattern and the first metal wire pattern. The second metal wire pattern covers at least two second contact plug patterns located on the same active area pattern, forming the second layout.

4. The test layout according to claim 3, characterized in that, The active area pattern is arranged in an S-shaped linear chain; or, The active region pattern is arranged in an array along a first direction and / or a second direction; wherein the first direction and the second direction are perpendicular to each other.

5. The test layout according to claim 4, characterized in that, The first metal wire pattern includes at least one first U-shaped pattern and at least one second U-shaped pattern.

6. The test layout according to claim 3, characterized in that, The sum of the lengths of the first metal wire patterns in the first version is equal to the sum of the lengths of the first metal wire patterns in the second version.

7. The test layout according to claim 1, characterized in that, The first pattern also includes two first contact pad patterns; the second pattern also includes two second contact pad patterns.

8. The test layout according to claim 1, characterized in that, The test layout also includes a gate layer, which comprises a plurality of gate patterns; The gate pattern is located on the active region pattern, and the first contact plug pattern and the second contact plug pattern are symmetrically distributed about the gate pattern.

9. A method for testing contact resistance, characterized in that, The method includes: A test structure is provided, the test structure including an active layer, a first contact plug layer, a first metal layer, a second contact plug layer and a second metal layer; Wherein, the active layer, the first contact plug layer, and the first metal layer constitute a first test structure, the first test structure including a first contact plug structure; the active layer, the first contact plug layer, the first metal layer, the second contact plug layer, and the second metal layer constitute a second test structure, the second test structure including a first contact plug structure and a second contact plug structure connected in parallel. Test voltages are applied to the first test structure and the second test structure to obtain the first contact resistance of the first contact plug structure and the second contact resistance of the second contact plug structure. The first test structure and the second test structure share the active layer.

10. The test method according to claim 9, characterized in that, The first test structure includes at least two first contact embolization structures; In the first test structure, the active layer is connected in series with the first metal layer through the first contact plug layer.

11. The test method according to claim 9, characterized in that, The second test structure includes at least two first contact embolization structures and at least two second contact embolization structures; In the second test structure, the active layer is connected in series with the first metal layer through the first contact plug layer; the first metal layer is connected in series with the second metal layer through the second contact plug layer. The active layer and the second metal layer are connected in parallel through the first contact plug layer and the second contact plug layer.

12. The test method according to claim 9, characterized in that, The step of applying a test voltage to the first test structure and the second test structure to obtain the first contact resistance of the first contact plug structure and the second contact plug structure includes: The test voltage is applied to the first test structure to obtain the first contact resistance of the first contact plug structure. The test voltage is applied to the second test structure to obtain the second contact resistance of the second contact plug structure.

13. The test method according to claim 12, characterized in that, The structure to be tested also includes two first contact pads, which are connected to the first test structure through the first metal layer. The step of applying the test voltage to the first test structure to obtain the first contact resistance of the first contact plug structure includes: The first current device and the first voltage device are respectively connected through the two first contact pads; After the test voltage is applied to the first test structure by the first voltage device, the first current of the first test structure is detected by the first current device. The first total resistance of the first test structure is obtained based on the test voltage and the first current. The first contact resistance of the first contact plug structure is obtained based on the first total resistance and the number of the first contact plug structures.

14. The test method according to claim 12, characterized in that, The structure to be tested also includes two second contact pads, which are connected to the second test structure through the first metal layer. The step of applying the test voltage to the second test structure to obtain the second contact resistance of the second contact plug structure includes: The second current device and the second voltage device are respectively connected through the two second contact pads; After the test voltage is applied to the second test structure by the second voltage device, the second current of the second test structure is detected by the second current device. The second total resistance of the second test structure is obtained based on the test voltage and the second current. The second contact resistance of the second contact plug structure is determined based on the second total resistance, the number of the first contact plug structures, the number of the second contact plug structures, and the first contact resistance.

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