Resistance test structure and resistance test method

Abstract

The invention relates to the technical field of semiconductors, and provides a resistance test structure and a resistance test method. The resistance test structure comprises a test resistor located on a semiconductor substrate, and the test resistor comprises a first end region, a second end region and a middle region located between the first end region and the second end region; the first end area is connected with the first end lead structure, the second end area is connected with the second end lead structure, the middle area is connected with at least one group of middle lead structures, and the middle lead structures, the first end lead structure and the second end lead structure divide the test resistor into a plurality of measurement sub-areas. In the measurement process, the measurement resistance value of each measurement sub-region and the overall measurement resistance value of the test resistor are measured independently, so that the redundant measurement resistance value is calculated, and the difference value between the overall measurement resistance value and the redundant measurement resistance value is used as the real measurement resistance value of the test resistor. And the accuracy of measuring the resistance value of the test resistor is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a resistance testing structure and a resistance testing method. Background Art

[0002] In the field of semiconductor manufacturing, with the development of technology, the size of semiconductor devices is getting smaller and smaller, while the complexity is getting higher and higher. In order to monitor the manufacturing process of semiconductor devices and ensure the reliability of semiconductor devices, it is common practice to form a test structure (test key) in the semiconductor device for testing and simulating some key parameters of the semiconductor device to ensure the quality of the semiconductor device before leaving the factory.

[0003] The test structure is usually manufactured in the same semiconductor process as the semiconductor devices in the wafer, and the test structure and the semiconductor devices have a mutual correspondence. Each layer of interconnection lines in the semiconductor device corresponds to the test lines located on the same layer in the test structure, and each plug in the semiconductor device corresponds to the test plug located on the same layer in the test structure. Since the test structure and the semiconductor device are prepared in the same process and have a mutual correspondence, the performance of the semiconductor device in the wafer can be obtained by detecting the performance of the test structure. The performance of the semiconductor device in the wafer is reflected by the test structure to avoid damage to the semiconductor device.

[0004] Resistors are an important part of circuit design. The accuracy of the resistors with resistance bar patterns commonly used in the current semiconductor industry seriously affects the performance of the circuit. The test structure includes a test resistor, and the resistance value is obtained by testing a special test resistor bar pattern. The resistance value obtained by the test is used to monitor whether each process step is normal and stable. When measuring the resistance value of the existing resistance test structure, due to the existence of contact resistance, the measured resistance value is not the actual resistance value of the test resistor, and the measurement result is inaccurate. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a resistance testing structure and a resistance testing method.

[0006] The present invention provides a resistance testing structure, comprising a test resistor located on a semiconductor substrate, wherein the test resistor comprises a first end region, a second end region and a middle region located between the first end region and the second end region; the first end region is connected to a first end lead structure, the second end region is connected to a second end lead structure, and the middle region is connected to at least one group of middle lead structures, and the at least one group of middle lead structures and the first end lead structure and the second end lead structure separate the test resistor into a plurality of measurement sub-regions.

[0007] In the embodiment of the present invention, the ohmic contact resistance value between the first end lead structure and the first end region, the ohmic contact resistance value between the second end lead structure and the second end region, and the ohmic contact resistance value between the middle lead structure and the middle region are all the same.

[0008] In an embodiment of the present invention, the middle region connects two groups of middle lead structures;

[0009] The measurement sub-region between the first end lead structure and the first group of middle lead structures is the first measurement sub-region;

[0010] The measurement sub-area between the first group of middle lead structures and the second group of middle lead structures is the second measurement area;

[0011] The measurement sub-region between the second group of middle lead structures and the second end lead structures is the third measurement region.

[0012] In an embodiment of the present invention, the first end lead structure includes a first contact plug and a first test key located on the first contact plug, and the first contact plug is in ohmic contact with the first end region;

[0013] The second end lead structure includes a second contact plug and a second test key located on the second contact plug, the second contact plug being in ohmic contact with the second end region;

[0014] Each group of middle lead structures includes a third contact plug and a third test key located on the third contact plug, and the third contact plug is in ohmic contact with the middle region.

[0015] In the embodiment of the present invention, the structure of the first contact plug, the structure of the second contact plug and the structure of the third contact plug are all the same;

[0016] The size of the first contact plug, the size of the second contact plug and the size of the third contact plug are all the same;

[0017] The structure of the first test key, the structure of the second test key and the structure of the third test key are all the same;

[0018] The size of the first test key, the size of the second test key, and the size of the third test key are all the same.

[0019] In the embodiment of the present invention, the first test key, the second test key and the third test key each include a plurality of metal layers, and adjacent metal layers are connected to each other;

[0020] The multiple metal layers are arranged in sequence along a direction perpendicular to the top surface of the test resistor, and the projection areas of the multiple metal layers toward the test resistor are the same.

[0021] In the embodiment of the present invention, each metal layer is provided with a plurality of anti-sag openings arranged in parallel.

[0022] In the embodiment of the present invention, the anti-sag openings of adjacent metal layers are perpendicular to each other.

[0023] The present invention also provides a resistance testing method, comprising:

[0024] Providing the above-mentioned resistance test structure, the resistance test structure is provided with a set of middle lead structures;

[0025] Performing resistance measurement based on a measurement sub-region between the first end lead structure and the middle lead structure to obtain a first measured resistance value;

[0026] Performing resistance measurement based on a measurement sub-region between the middle lead structure and the second end lead structure to obtain a second measured resistance value;

[0027] Performing resistance measurement based on the entire measurement area between the first end lead structure and the second end lead structure to obtain a third measured resistance value;

[0028] Calculating a redundant resistance value according to the first measured resistance value, the second measured resistance value, and the third measured resistance value;

[0029] The difference between the third measured resistance value and the redundant resistance value is calculated as the actual resistance value of the test resistor.

[0030] The present invention also provides another resistance testing method, comprising:

[0031] Providing the above-mentioned resistance test structure, the resistance test structure is provided with two sets of middle lead structures;

[0032] Performing resistance measurement based on a measurement sub-region between the first end lead structure and the first group of middle lead structures to obtain a first measured resistance value;

[0033] Performing resistance measurement based on the measurement sub-region between the first group of middle lead structures and the second group of middle lead structures to obtain a second measured resistance value;

[0034] Performing resistance measurement based on the measurement sub-region between the second group of middle lead structures and the second end lead structure to obtain a third measured resistance value;

[0035] Performing resistance measurement based on the entire measurement area between the first end lead structure and the second end lead structure to obtain a fourth measured resistance value;

[0036] Calculating a redundant resistance value according to the first measured resistance value, the second measured resistance value, the third measured resistance value, and the fourth measured resistance value;

[0037] The difference between the fourth measured resistance value and the redundant resistance value is calculated as the actual resistance value of the test resistor.

[0038] The present invention sets one or more sets of middle lead structures in the middle area of ​​the test resistor, and the test resistor can be divided into multiple measurement sub-areas through the first end lead structure, the second end lead structure and the middle lead structure. During the measurement process, the measured resistance value of each measurement sub-area and the overall measured resistance value of the test resistor are measured separately, so as to calculate the redundant measured resistance value, and finally the real measured resistance value of the test resistor can be obtained by calculating the difference between the overall measured resistance value and the redundant measured resistance value, thereby avoiding the problem of inaccurate measurement results caused by the contact resistance between the lead structure and the test resistor, and improving the accuracy of the resistance measurement of the test resistor.

[0039] Other features and advantages of the technical solution of the present invention will be described in detail in the specific implementation section below. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0041] Figure 1 is a schematic diagram of a resistance testing structure provided by an embodiment of the present invention;

[0042] Figure 2 is along Figure 1 Schematic diagram of the cross section along the AA line;

[0043] Figure 3 is a structural schematic diagram of a test key of a resistance test structure provided by an embodiment of the present invention;

[0044] Figure 4 is along Figure 3 Schematic diagram of the cross section of the middle BB line;

[0045] Figure 5 is a schematic structural diagram of adjacent metal layers in a test key provided by an embodiment of the present invention;

[0046] Figure 6 is a schematic diagram of a resistance testing structure provided by another embodiment of the present invention;

[0047] Figure 7 is a schematic diagram of a resistance testing structure provided by another embodiment of the present invention;

[0048] Figure 8 is a schematic diagram of a resistance testing structure provided by another embodiment of the present invention;

[0049] Fig. 9 It is a flow chart of a resistance testing method provided by an embodiment of the present invention.

[0050] Description of Reference Numerals

[0051] 100-semiconductor substrate, 101-test resistor,

[0052] I-first end region, II-second end region, III-middle region,

[0053] 102 - first end lead structure, 1021 - first contact plug, 1022 - first test key,

[0054] 103 - second end lead structure, 1031 - second contact plug, 1032 - second test key,

[0055] 104-middle lead structure, 1041-third contact plug, 1042-third test key,

[0056] 105 - metal layer, 1051 - anti-sag opening. DETAILED DESCRIPTION

[0057] In order to make the technical solutions and advantages of the embodiments of the present invention more clearly understood, the exemplary embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than an exhaustive list of all the embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0058] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0059] In the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", "connected" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] As described in the background art, when measuring the resistance value of the existing resistance test structure, due to the existence of contact resistance, the measured resistance value is not the actual resistance value of the test resistor, and the measurement result is inaccurate.

[0061] In view of the above problems, an embodiment of the present invention provides a resistance test structure, including a test resistor located on a semiconductor substrate, the test resistor including a first end region, a second end region and a middle region located between the first end region and the second end region, the first end region is connected to a first end lead structure, the second end region is connected to a second end lead structure, the middle region is connected to at least one group of middle lead structures, and the middle lead structure, the first end lead structure and the second end lead structure separate the test resistor into a plurality of measurement sub-regions. The present invention sets one or more groups of middle lead structures in the middle region of the test resistor, and the structures of the first end lead structure, the second end lead structure and the middle lead structure are the same, so the redundant measurement resistance values ​​caused by the first end lead structure, the second end lead structure and the middle lead structure are also the same during each measurement. During the measurement process, the test resistor can be divided into multiple measurement sub-areas through the first end lead structure, the second end lead structure and the middle lead structure. The redundant measurement resistance value is calculated by separately measuring the measurement resistance value of each measurement sub-area and the overall measurement resistance value of the test resistor. Finally, the true measurement resistance value of the test resistor can be obtained by calculating the difference between the overall measurement resistance value and the redundant measurement resistance value, thereby avoiding the problem of inaccurate measurement results due to the contact resistance between the lead structure and the test resistor, and improving the accuracy of the resistance measurement of the test resistor.

[0062] Figure 1 FIG. 1 is a schematic diagram of a resistance test structure provided by an embodiment of the present invention. Figure 1As shown, the resistance test structure of the present embodiment includes a semiconductor substrate 100 and a test resistor 101 located in or on the semiconductor substrate 100, the test resistor 101 includes a first end region I, a second end region II and a middle region III located between the first end region I and the second end region II, and also includes a first end lead structure 102 located on the first end region I and connected to the first end region I, a second end lead structure 103 located on the second end region II and connected to the second end region II, and a group of middle lead structures 104 located on the middle region III and connected to the middle region III.

[0063] The first end lead structure 102, the second end lead structure 103 and the middle lead structure 104 have the same structure, so that the ohmic contact resistance of each lead structure and each area of ​​the test resistor is the same, that is, the ohmic contact resistance value of the first end lead structure 102 and the first end area I, the ohmic contact resistance value of the second end lead structure 103 and the second end area II, and the ohmic contact resistance value of the middle lead structure 104 and the middle area III are all the same. The middle lead structure 104 and the first end lead structure 102 and the second end lead structure 103 separate the test resistor into two measurement sub-areas. Among them, the measurement sub-area between the first end lead structure 102 and the middle lead structure 104 is the first measurement area, and the measurement sub-area between the middle lead structure 104 and the second end lead structure 103 is the second measurement area.

[0064] In this embodiment, a group of middle lead structures 104 is set in the middle area III, and the first end lead structure 102, the second end lead structure 103 and the middle lead structure 104 have the same structure, so the redundant measured resistance values ​​caused by the first end lead structure 102, the second end lead structure 103 and the middle lead structure 104 are also the same during each measurement. During the measurement process, the test resistor 101 can be divided into two measurement sub-areas based on the first end lead structure 102, the second end lead structure 103 and the middle lead structure 104, and the measured resistance values ​​of the two measurement sub-areas and the overall measured resistance value of the test resistor 101 are measured separately, and then the redundant measured resistance value can be calculated through operation, and finally the real measured resistance value of the test resistor 101 can be obtained through the difference between the overall measured resistance value and the redundant measured resistance value, thereby improving the accuracy of the resistance measurement of the test resistor 101.

[0065] It should be noted that the resistance test structure is usually manufactured in the same semiconductor process as the semiconductor device in the wafer, and the resistance test structure and the semiconductor device have a mutual correspondence. Each layer of interconnection lines in the semiconductor device corresponds to the test line located in the same layer in the resistance test structure, and each plug in the semiconductor device corresponds to the test plug located in the same layer in the resistance test structure. Since the resistance test structure and the semiconductor device are prepared in the same process and have a mutual correspondence, the resistance value of the corresponding semiconductor device in the wafer can be obtained by detecting the resistance value of the resistance test structure. By reflecting some parameters of the semiconductor device in the wafer through the resistance test structure, damage to the semiconductor device in the wafer is avoided.

[0066] Since the resistance test structure is only used to test the parameters of semiconductor devices in the wafer and will not be eventually made into a product for actual use, in order to ensure that the resistance test structure does not occupy the area of ​​the semiconductor devices that are actually put into use in the wafer, the resistance test structure can be formed in the cutting area of ​​the wafer. After the test is completed, the resistance test structure will also be damaged during the process of cutting the wafer.

[0067] Figure 2 is along Figure 1 Schematic diagram of the cross section along line AA. Figure 2 The test keys for each lead structure are omitted. Figure 3 FIG. 1 is a schematic diagram of the structure of a test key provided by an embodiment of the present invention. Figure 2 and Figure 3 As shown, in this embodiment, the first end lead structure 102 includes a first contact plug 1021 and a first test key 1022 located on the first contact plug 1021, and the first contact plug 1021 is in ohmic contact with the first end region I. The second end lead structure 103 includes a second contact plug 1031 and a second test key 1032 located on the second contact plug 1031, and the second contact plug 1031 is in ohmic contact with the second end region II. The middle lead structure 104 includes a third contact plug 1041 and a third test key 1042 located on the third contact plug 1041, and the third contact plug 1041 is in ohmic contact with the middle region III.

[0068] It should be noted that, in the present embodiment, the redundant measurement resistance value generated during the measurement process mainly originates from the ohmic contact between the first contact plug 1021, the second contact plug 1031 or the third contact plug 1041 and the test resistor 101. The internal contacts of the first test key 1022, the second test key 1032 and the third test key 1042, and the contacts between the first test key 1022 and the first test key 1022, between the second test key 1032 and the second test key 1032, and between the third test key 1042 and the third test key 1042 are all metal contacts, and the redundant measurement resistance values ​​generated by these contacts are very small and can be ignored.

[0069] In this embodiment, the structure of the first contact plug 1021, the structure of the second contact plug 1031, and the structure of the third contact plug 1041 are all the same; the size of the first contact plug 1021, the size of the second contact plug 1031, and the size of the third contact plug 1041 are all the same; the number of the first contact plug 1021, the second contact plug 1031, and the third contact plug 1041 is also the same. The structure of the first test key 1022, the structure of the second test key 1032, and the structure of the third test key 1042 are all the same, and the size of the first test key 1022, the size of the second test key 1032, and the size of the third test key 1042 are all the same.

[0070] like Figure 3 and Figure 4 As shown, in one embodiment, the first test key 1022, the second test key 1032 and the third test key 1042 each include a plurality of metal layers 105, and adjacent metal layers 105 are connected to each other. The plurality of metal layers 105 are arranged in sequence along a direction perpendicular to the top surface of the test resistor 101, and the projection areas of the plurality of metal layers 105 toward the test resistor 101 are the same.

[0071] like Figure 5 As shown, in one embodiment, each metal layer 105 is provided with a plurality of anti-sag openings 1051 arranged in parallel. The anti-sag openings 1051 can prevent the problem of the middle area of ​​the metal layer 105 from being sunken during the process of flattening the metal layer 105, thereby improving the electrical contact of the metal layer 105. The anti-sag openings 1051 of adjacent metal layers 105 are perpendicular to each other. By vertically arranging the anti-sag openings of adjacent metal layers, the distribution of the overall structure of the test key is made more uniform, thereby improving the conductive performance of the test key.

[0072] In this embodiment, the material of the semiconductor substrate 100 may be silicon, or may be germanium, silicon germanium, silicon carbide, gallium arsenide, or indium gallium.

[0073] In this embodiment, the middle lead structure 104 may be located at any position in the middle region III.

[0074] In this embodiment, the test resistor 101 is an ion region implanted into the semiconductor substrate 100 , and the implanted ions may be N-type ions or P-type ions.

[0075] In this embodiment, the test resistor 101 is a straight line structure extending along a first direction X, and the first direction X is parallel to the top surface of the semiconductor substrate 100 .

[0076] Figure 6 FIG. 1 is a schematic diagram of a resistance test structure provided by another embodiment of the present invention. Figure 6 As shown, the resistance test structure provided in this embodiment includes a semiconductor substrate 100 and a test resistor 101 located in or on the semiconductor substrate 100, the test resistor 101 includes a first end region I, a second end region II and a middle region III located between the first end region I and the second end region II, and also includes a first end lead structure 102 located on the first end region I and connected to the first end region I, a second end lead structure 103 located on the second end region II and connected to the second end region II, and two groups of middle lead structures 104 located on the middle region III and connected to the middle region III. Each lead structure includes at least one contact plug and at least one test key, the test key includes a plurality of metal layers, and each metal layer is provided with a plurality of anti-recess openings arranged in parallel. For the specific conditions of each lead structure in this embodiment and the specific conditions of the contact plugs and test keys of each lead structure, please refer to Figure 2 , Figure 3 , Figure 4 , Figure 5 and the description of the above embodiments.

[0077] In this embodiment, there are two groups of middle lead structures, and the two groups of middle lead structures 104, the first end lead structure 102, and the second end lead structure 103 separate the test resistor into three measurement sub-areas. Among them, the measurement sub-area between the first end lead structure 102 and the first group of middle lead structures 104 is the first measurement area, the measurement sub-area between the first group of middle lead structures and the second group of middle lead structures is the second measurement area, and the measurement sub-area between the second group of middle lead structures 104 and the second end lead structure 103 is the third measurement area.

[0078] In this embodiment, two groups of middle lead structures 104 are arranged in the middle area III, and the first end lead structure 102, the second end lead structure 103 and the two groups of middle lead structures 104 have the same structure, so the redundant measured resistance values ​​caused by the first end lead structure 102, the second end lead structure 103 and the middle lead structure 104 are also the same in each measurement. During the measurement process, the test resistor can be divided into three measurement sub-areas by the first end lead structure, the second end lead structure and the middle lead structure, and the measured resistance values ​​of each measurement sub-area and the overall measured resistance value of the test resistor are measured separately, and the difference between the sum of the measured resistance values ​​of the three measurement sub-areas and the fourth measured resistance value is calculated, and the value obtained by dividing it by the number N of the middle lead structures is used as the redundant measured resistance value, and finally the real measured resistance value of the test resistor can be obtained by calculating the difference between the overall measured resistance value and the redundant measured resistance value.

[0079] Figure 7 FIG. 1 is a schematic diagram of a resistance test structure provided by another embodiment of the present invention. Figure 7 As shown, this embodiment continues to illustrate the resistance test structure based on the above embodiment, and is different from the above embodiment in that: the test resistor 101 can also be a reciprocating serpentine line structure.

[0080] Figure 8 FIG. 1 is a schematic diagram of a resistance test structure provided by another embodiment of the present invention. Figure 8 As shown, this embodiment continues to describe the resistance test structure based on the above embodiment, and is different from the above embodiment in that: the test resistor 101 is a polysilicon structure formed on the semiconductor substrate 100 .

[0081] Fig. 9 FIG. 1 is a flow chart of a resistance testing method provided by an embodiment of the present invention. Fig. 9 As shown, the resistance testing method of this embodiment includes the following steps:

[0082] S901, providing the resistance test structure of the above embodiment;

[0083] S902, performing resistance measurement based on a measurement sub-region between the first end lead structure and the middle lead structure to obtain a first measured resistance value;

[0084] S903, performing resistance measurement based on a measurement sub-region between the middle lead structure and the second end lead structure to obtain a second measured resistance value;

[0085] S904, performing resistance measurement based on the entire measurement area between the first end lead structure and the second end lead structure to obtain a third measured resistance value;

[0086] S905, calculating a redundant resistance value according to the first measured resistance value, the second measured resistance value, and the third measured resistance value;

[0087] S906, calculating a difference between the third measured resistance value and the redundant resistance value as a true resistance value of the test resistor.

[0088] In a specific embodiment, the resistance test structure provided has only one set of middle lead structures. One set of middle lead structures 104 and the first end lead structure 102 and the second end lead structure 103 separate the test resistor into two measurement sub-areas. Among them, the measurement sub-area between the first end lead structure 102 and the middle lead structure 104 is the first measurement area S1, and the measurement sub-area between the middle lead structure 104 and the second end lead structure 103 is the second measurement area S2. The overall measurement area of ​​the first end lead structure 102 and the second end lead structure 103 is the third measurement area S3.

[0089] The specific measurement process is as follows:

[0090] First, the resistance value of the resistance region between the first end lead structure 102 and the middle lead structure 104 is measured to obtain a first measured resistance value R S1 ';

[0091] Then, the resistance value of the resistance region between the middle lead structure 104 and the second end lead structure 103 is measured to obtain a second measured resistance value R S2 ';

[0092] Then, the resistance value of the entire resistance area between the first end lead structure 102 and the second end lead structure 103 is measured to obtain a third measured resistance value R S3 '.

[0093] Since there is contact resistance between the lead structure and the test resistor, redundant resistance is introduced, so the measured resistance value of each measurement area includes the redundant resistance R 冗余 ,Right now:

[0094] The actual resistance value R of the first measurement area S1 S1 =R S1 '-R 冗余 ;

[0095] The actual resistance value R of the second measurement area S2 S2 =R S2 '-R 冗余 ;

[0096] The actual resistance value R of the third measurement area S3 S3 =R S3 '-R 冗余 ;

[0097] Since the actual resistance value of the third measurement area S3 is equal to the sum of the actual resistance value of the first measurement area S1 and the actual resistance value of the second measurement area S2, that is: R S1 +R S2 =R S3 , R S1 =R S1 '-R 冗余 , R S2 =R S2 '-R 冗余 , R S3 =R S3 '-R 冗余 Substituting this into the equation, we get the following equation:

[0098] R S1 '-R 冗余 +R S2 '-R 冗余 =R S3 '-R 冗余 ;

[0099] R 冗余 =R S1 '+R S2 '-R S3 ';

[0100] According to the first measured resistance value R S1 ', the second measured resistance value R S2 ', the third measured resistance value R S3 ', we can calculate R 冗余 .

[0101] According to R S3 =R S3 '-R 冗余 , the actual resistance value R of the third measurement area S3 can be calculated S3 , the actual resistance value R of the third measurement area S3 S3 That is the true resistance value of the entire test resistor.

[0102] It should be noted that two lead structures are required in each measurement process, and the structure of each lead structure is the same, so each measurement generates a redundant measurement resistance value R 冗余 The same is true. By applying a preset voltage to the corresponding measurement area and then measuring the current value, the corresponding measurement resistance value is calculated.

[0103] In another specific embodiment, the resistor test structure provided has two groups of middle lead structures. The two groups of middle lead structures 104 and the first end lead structure 102 and the second end lead structure 103 separate the test resistor into three measurement sub-areas. Among them, the measurement sub-area between the first end lead structure 102 and the first group of middle lead structures 104 is the first measurement area S1, the measurement sub-area between the first group of middle lead structures and the second group of middle lead structures is the second measurement area S2, and the measurement sub-area between the second group of middle lead structures 104 and the second end lead structure 103 is the third measurement area S3. The overall measurement area of ​​the first end lead structure 102 and the second end lead structure 103 is the fourth measurement area S4.

[0104] The specific measurement process is as follows:

[0105] First, the resistance value of the resistance region between the first end lead structure 102 and the first group of middle lead structures 104 is measured to obtain a first measured resistance value R S1 ';

[0106] Then, the resistance value of the resistance region between the first group of middle lead structures 104 and the second group of middle lead structures 104 is measured to obtain a second measured resistance value R S2 ';

[0107] Then, the resistance value of the resistance region between the second group of middle lead structures 104 and the second end lead structures 103 is measured to obtain a second measured resistance value R S3 ';

[0108] Then, the resistance value of the entire resistance area between the first end lead structure 102 and the second end lead structure 103 is measured to obtain a fourth measured resistance value R S4 '.

[0109] Since there is contact resistance between the lead structure and the test resistor, redundant resistance is introduced, so the measured resistance value of each measurement area includes the redundant resistance R 冗余 ,Right now:

[0110] The actual resistance value R of the first measurement area S1 S1 =R S1 '-R 冗余 ;

[0111] The actual resistance value R of the second measurement area S2 S2 =R S2 '-R 冗余 ;

[0112] The actual resistance value R of the third measurement area S3 S3 =R S3 '-R 冗余 ;

[0113] The actual resistance value R of the fourth measurement area S4 S4 =R S4 '-R 冗余 ;

[0114] Since the actual resistance value of the fourth measurement area S4 is equal to the sum of the actual resistance value of the first measurement area S1, the actual resistance value of the second measurement area S2 and the actual resistance value of the third measurement area S3, that is: R S1 +R S2 +R S3 =R S4 ;

[0115] R S1 =R S1 '-R 冗余 , R S2 =R S2 '-R 冗余 , R S3 =R S3 '-R 冗余 , R S4 =R S4 '-R 冗余 Substituting into the above equation, we get the following equation:

[0116] R S1 '-R 冗余 +R S2 '-R 冗余 +R S3 '-R 冗余 =R S4 '-R 冗余 ;

[0117] R S1 '+R S2 '+R S3 '-R S4 '=2*R 冗余 ;

[0118] According to the first measured resistance value R S1 ', the second measured resistance value R S2 ', the third measured resistance value R S3 ', the fourth measured resistance value R S4 ', we can calculate R 冗余 .

[0119] According to R S4 =R S4 '-R 冗余 , the actual resistance value R of the fourth measurement area S4 can be calculated S4 , the actual resistance value R of the fourth measurement area S4 S4That is the true resistance value of the entire test resistor.

[0120] If the resistance test structure has three or more sets of middle lead structures, a similar method can be used to calculate the redundant resistance value, thereby calculating the true resistance value of the entire test resistor.

[0121] The optional embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the technical concept of the embodiments of the present invention, a variety of simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all belong to the protection scope of the embodiments of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction, and as long as the combination does not violate the concept of the embodiments of the present invention, it should also be regarded as the content disclosed in the embodiments of the present invention.

Claims

1. A resistance test structure, comprising a test resistor located on a semiconductor substrate, characterized in that: The test resistor includes a first end region, a second end region, and a middle region between the first end region and the second end region; The first end region is connected to a first end lead structure, the second end region is connected to a second end lead structure, and the middle region is connected to at least one group of middle lead structures. The at least one group of middle lead structures and the first end lead structure and the second end lead structure separate the test resistor into multiple measurement sub-regions.

2. The resistance test structure according to claim 1, characterized in that: The ohmic contact resistance between the first end lead structure and the first end region, the ohmic contact resistance between the second end lead structure and the second end region, and the ohmic contact resistance between the middle lead structure and the middle region are all the same.

3. The resistance testing structure according to claim 1, characterized in that: The middle region connects two sets of middle lead structures; The measurement sub-region between the first end lead structure and the first group of middle lead structures is the first measurement sub-region; The measurement sub-area between the first group of middle lead structures and the second group of middle lead structures is the second measurement area; The measurement sub-region between the second group of middle lead structures and the second end lead structures is the third measurement region.

4. The resistance testing structure according to claim 1, characterized in that: The first end lead structure includes a first contact plug and a first test key located on the first contact plug, the first contact plug being in ohmic contact with the first end region; The second end lead structure includes a second contact plug and a second test key located on the second contact plug, the second contact plug being in ohmic contact with the second end region; Each group of middle lead structures includes a third contact plug and a third test key located on the third contact plug, and the third contact plug is in ohmic contact with the middle region.

5. The resistance testing structure according to claim 4, characterized in that: The structure of the first contact plug, the structure of the second contact plug and the structure of the third contact plug are all the same; The size of the first contact plug, the size of the second contact plug and the size of the third contact plug are all the same; The structure of the first test key, the structure of the second test key and the structure of the third test key are all the same; The size of the first test key, the size of the second test key, and the size of the third test key are all the same.

6. The resistance testing structure according to claim 4, characterized in that: The first test key, the second test key and the third test key each include a plurality of metal layers, and adjacent metal layers are connected to each other; The multiple metal layers are arranged in sequence along a direction perpendicular to the top surface of the test resistor, and the projection areas of the multiple metal layers toward the test resistor are the same.

7. The resistance testing structure according to claim 6, characterized in that: Each metal layer is provided with a plurality of anti-sag openings arranged in parallel.

8. The resistance testing structure according to claim 7, characterized in that: The anti-sag openings of adjacent metal layers are perpendicular to each other.

9. A resistance testing method, characterized in that: include: Providing the resistance test structure of claim 1, wherein the resistance test structure is provided with a set of middle lead structures; Performing resistance measurement based on a measurement sub-region between the first end lead structure and the middle lead structure to obtain a first measured resistance value; Performing resistance measurement based on a measurement sub-region between the middle lead structure and the second end lead structure to obtain a second measured resistance value; Performing resistance measurement based on the entire measurement area between the first end lead structure and the second end lead structure to obtain a third measured resistance value; Calculating a redundant resistance value according to the first measured resistance value, the second measured resistance value, and the third measured resistance value; The difference between the third measured resistance value and the redundant resistance value is calculated as the actual resistance value of the test resistor.

10. A resistance testing method, characterized in that: include: Providing the resistance test structure of claim 1, wherein the resistance test structure is provided with two sets of middle lead structures; Performing resistance measurement based on a measurement sub-region between the first end lead structure and the first group of middle lead structures to obtain a first measured resistance value; Performing resistance measurement based on the measurement sub-region between the first group of middle lead structures and the second group of middle lead structures to obtain a second measured resistance value; Performing resistance measurement based on the measurement sub-region between the second group of middle lead structures and the second end lead structure to obtain a third measured resistance value; Performing resistance measurement based on the entire measurement area between the first end lead structure and the second end lead structure to obtain a fourth measured resistance value; Calculating a redundant resistance value according to the first measured resistance value, the second measured resistance value, the third measured resistance value, and the fourth measured resistance value; The difference between the fourth measured resistance value and the redundant resistance value is calculated as the actual resistance value of the test resistor.

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