Test Structure and Test Method for Active Region Resistance

Abstract

The present invention discloses a test structure for an active region resistance, which includes: an active region resistance, a first and a second contact hole provided at the first end of the active region resistance, and a third and a fourth contact hole provided at the second end of the active region resistance. The first to fourth contact holes are respectively connected to first to fourth pads. Test ports for first to sixth groups of resistors are respectively formed between the first and the second pads, between the third and the fourth pads, between the first and the third pads, between the second and the fourth pads, between the first and the fourth pads, and between the second and the third pads. The measured value of the active region resistance is half of the difference obtained by subtracting the sum of the first and second groups of resistors from the sum of the third and fourth groups of resistors or the sum of the fifth and sixth groups of resistors. The present invention also provides a method for testing an active region resistance. The present invention can improve the measurement accuracy of the active region resistance.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor integrated circuit manufacturing, and in particular to a test structure for an active region resistance. The present invention also relates to a test method for an active region resistance. Background Art

[0002] As Figure 1 shown, it is a structural diagram of a conventional test structure for an active region resistance; the conventional test structure for an active region resistance includes:

[0003] An active region resistance 101, which is composed of a doped region formed in an active region.

[0004] A contact hole 102a is provided at a first end of the active region resistance 101.

[0005] A contact hole 102b is provided at a second end of the active region resistance 101.

[0006] The contact hole 102a is connected to a pad 103a, and the contact hole 102b is connected to a pad 103b. Figure 1 In, the pad 103a is also denoted as pad1, and the pad 103b is also denoted as pad2.

[0007] Figure 1 In, a test port of the resistance is formed by the pad 103a and the pad 103b and is used to test and obtain the resistance value of the active region resistance 101.

[0008] The sheet resistance of the active region resistance 101 can be obtained by multiplying the resistance value of the active region resistance 101 by the ratio of the width and length of the active region resistance 101. According to Figure 1 shown, the formula for the sheet resistance of the active region resistance 101 is:

[0009] RS = (R1 + RC1 + R + RC2 + R2) * W / L Formula (101);

[0010] Wherein, RS represents the sheet resistance of the active region resistance 101, W represents the width of the active region resistance 101, and L represents the length of the active region resistance 101;

[0011] R1 represents the parasitic resistance of the pad 103a, and R2 represents the parasitic resistance of the pad 103b;

[0012] RC1 represents the parasitic resistance of the contact hole 102a, and RC2 represents the parasitic resistance of the contact hole 102b;

[0013] R represents the active region resistance.

[0014] Due to the existence of the resistance of the test circuit and the parasitic resistance RC of the contact hole (CT), using the existing test structure shown in Figure 1 for measurement will result in inaccurate measurement results. SUMMARY OF THE INVENTION

[0015] The technical problem to be solved by the present invention is to provide a test structure for the resistance of the active region, which can provide multiple sets of test ports and obtain the measured value of the resistance of the active region through the test of multiple sets of test ports, and can eliminate the influence of the parasitic resistance of the contact hole and the connection wire on the measured value of the resistance of the active region, so as to improve the measurement accuracy of the resistance of the active region. For this purpose, the present invention also provides a test method for the resistance of the active region.

[0016] To solve the above technical problem, the test structure for the resistance of the active region provided by the present invention includes:

[0017] The resistance of the active region, which is composed of a doped region formed in the active region.

[0018] A first contact hole and a second contact hole are provided at the first end of the resistance of the active region.

[0019] A third contact hole and a fourth contact hole are provided at the second end of the resistance of the active region.

[0020] The first contact hole is connected to the first pad, the second contact hole is connected to the second pad, the third contact hole is connected to the third pad, and the fourth contact hole is connected to the fourth pad.

[0021] A test port for the first group of resistors is formed between the first pad and the second pad and is used to test and obtain the first group of resistors.

[0022] A test port for the second group of resistors is formed between the third pad and the fourth pad and is used to test and obtain the second group of resistors.

[0023] A test port for the third group of resistors is formed between the first pad and the third pad and is used to test and obtain the third group of resistors.

[0024] A test port for the fourth group of resistors is formed between the second pad and the fourth pad and is used to test and obtain the fourth group of resistors.

[0025] A test port for the fifth group of resistors is formed between the first pad and the fourth pad and is used to test and obtain the fifth group of resistors.

[0026] A test port for the sixth group of resistors is formed between the second pad and the third pad and is used to test and obtain the sixth group of resistors.

[0027] The measured value of the active region resistance is half of the difference obtained by subtracting the sum of the first group of resistors and the second group of resistors from the sum of the third group of resistors and the fourth group of resistors; or, the measured value of the active region resistance is half of the difference obtained by subtracting the sum of the first group of resistors and the second group of resistors from the sum of the fifth group of resistors and the sixth group of resistors.

[0028] A further improvement is that the active region is surrounded by field oxide formed in a semiconductor substrate.

[0029] A further improvement is that the semiconductor substrate includes a silicon substrate.

[0030] A further improvement is that the field oxide is shallow trench isolation or local field oxide.

[0031] A further improvement is that the doped region of the active region resistance is an N-type doped region or a P-type doped region.

[0032] A further improvement is that the first contact hole, the second contact hole, the third contact hole, the fourth contact hole, the first pad, the second pad, the third pad, and the fourth pad all have parasitic resistances, and the parasitic resistances of the first contact hole, the second contact hole, the third contact hole, the fourth contact hole, the first pad, the second pad, the third pad, and the fourth pad are eliminated in the measured value of the active region resistance.

[0033] A further improvement is that an interlayer film is formed on the surface of the semiconductor substrate, and the first contact hole, the second contact hole, the third contact hole, and the fourth contact hole all pass through the interlayer film.

[0034] The first pad, the second pad, the third pad, and the fourth pad are all formed on the surface of the interlayer film.

[0035] To solve the above technical problems, the active region resistance testing method provided by the present invention includes the following steps:

[0036] Step 1, forming a test structure, the test structure includes:

[0037] An active region resistance, which is composed of a doped region formed in the active region.

[0038] A first contact hole and a second contact hole are provided at the first end of the active region resistance.

[0039] A third contact hole and a fourth contact hole are provided at the second end of the active region resistance.

[0040] The first contact hole is connected to the first pad, the second contact hole is connected to the second pad, the third contact hole is connected to the third pad, and the fourth contact hole is connected to the fourth pad.

[0041] Step 2: Conduct a resistance test.

[0042] The resistance test includes:

[0043] Using the first pad and the second pad as two test ports to conduct a test to obtain a first set of resistances;

[0044] Using the third pad and the fourth pad as two test ports to conduct a test to obtain a second set of resistances;

[0045] Using the first pad and the third pad as two test ports to conduct a test to obtain a third set of resistances;

[0046] Using the second pad and the fourth pad as two test ports to conduct a test to obtain a fourth set of resistances.

[0047] Alternatively, the resistance test includes:

[0048] Using the first pad and the second pad as two test ports to conduct a test to obtain a first set of resistances;

[0049] Using the third pad and the fourth pad as two test ports to conduct a test to obtain a second set of resistances;

[0050] Using the first pad and the fourth pad as two test ports to conduct a test to obtain a fifth set of resistances;

[0051] Using the second pad and the third pad as two test ports to conduct a test to obtain a sixth set of resistances.

[0052] Step 3: Calculate the measured value of the active region resistance.

[0053] The measured value of the active region resistance is half of the difference obtained by subtracting the sum of the first set of resistances and the second set of resistances from the sum of the third set of resistances and the fourth set of resistances;

[0054] Alternatively, the measured value of the active region resistance is half of the difference obtained by subtracting the sum of the first set of resistances and the second set of resistances from the sum of the fifth set of resistances and the sixth set of resistances.

[0055] A further improvement is that the active region is surrounded by field oxide formed in a semiconductor substrate.

[0056] A further improvement is that the semiconductor substrate includes a silicon substrate.

[0057] A further improvement is that the field oxide is shallow trench isolation or local field oxide.

[0058] A further improvement is that the doped region of the active region resistance is an N-type doped region or a P-type doped region.

[0059] A further improvement is that the first contact hole, the second contact hole, the third contact hole, the fourth contact hole, the first pad, the second pad, the third pad, and the fourth pad all have parasitic resistances, and the parasitic resistances of the first contact hole, the second contact hole, the third contact hole, the fourth contact hole, the first pad, the second pad, the third pad, and the fourth pad are eliminated from the measured value of the active region resistance.

[0060] A further improvement is that an interlayer film is formed on the surface of the semiconductor substrate, and the first contact hole, the second contact hole, the third contact hole, and the fourth contact hole all pass through the interlayer film.

[0061] The first pad, the second pad, the third pad, and the fourth pad are all formed on the surface of the interlayer film.

[0062] A further improvement is that it further includes: Step Four, calculating the sheet resistance of the active region resistance.

[0063] The sheet resistance of the active region resistance is the measured value of the active region resistance multiplied by the ratio of the width and length of the active region resistance.

[0064] In the present invention, two contact holes and two pads are provided at both ends of the active region resistance. Up to six groups of test ports can be formed among the four pads and six groups of resistances can be obtained. The measured value of the active region resistance without the parasitic resistances of the contact holes and pads can be obtained by using the first to fourth groups of resistances or the first, second, fifth, and sixth groups of resistances. Therefore, the present invention can provide multiple groups of test ports and obtain the measured value of the active region resistance through the test of multiple groups of test ports, and can eliminate the influence of the parasitic resistances of the contact holes and the connection wires on the measured value of the active region resistance, thereby improving the measurement accuracy of the active region resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The present invention will be further described in detail below with reference to the drawings and specific embodiments:

[0066] Figure 1 is a structural diagram of a conventional test structure for an active region resistance;

[0067] Figure 2 is a structural diagram of a test structure for an active region resistance according to an embodiment of the present invention;

[0068] Figure 3It is a formula derivation diagram of the measured value of the active region resistance in an embodiment of the present invention. Detailed implementation manners

[0069] As Figure 2 shown, it is a structural diagram of a test structure for the active region resistance in an embodiment of the present invention; the test structure for the active region resistance in an embodiment of the present invention includes:

[0070] An active region resistance 201, which is composed of a doped region formed in the active region.

[0071] A first contact hole 202a and a second contact hole 202b are provided at the first end of the active region resistance 201.

[0072] A third contact hole 202c and a fourth contact hole 202d are provided at the second end of the active region resistance 201.

[0073] The first contact hole 202a is connected to a first pad 203a, the second contact hole 202b is connected to a second pad 203b, the third contact hole 202c is connected to a third pad 203c, and the fourth contact hole 202d is connected to a fourth pad 203d. Figure 2 In [description], the first pad 203a is also denoted as pad1, the second pad 203b is also denoted as pad2, the third pad 203c is also denoted as pad3, and the fourth pad 203d is also denoted as pad4.

[0074] In an embodiment of the present invention, the active region is surrounded by field oxide formed in a semiconductor substrate.

[0075] The semiconductor substrate includes a silicon substrate.

[0076] The field oxide is shallow trench isolation or local field oxide.

[0077] The doped region of the active region resistance 201 is an N-type doped region or a P-type doped region.

[0078] An interlayer film is formed on the surface of the semiconductor substrate, and the first contact hole 202a, the second contact hole 202b, the third contact hole 202c, and the fourth contact hole 202d all pass through the interlayer film.

[0079] The first pad 203a, the second pad 203b, the third pad 203c, and the fourth pad 203d are all formed on the surface of the interlayer film.

[0080] A test port for a first group of resistances is formed between the first pad 203a and the second pad 203b and is used to test and obtain the first group of resistances.

[0081] A test port for a second set of resistors is formed between the third gasket 203c and the fourth gasket 203d and is used to test and obtain the second set of resistors.

[0082] A test port for a third set of resistors is formed between the first gasket 203a and the third gasket 203c and is used to test and obtain the third set of resistors.

[0083] A test port for a fourth set of resistors is formed between the second gasket 203b and the fourth gasket 203d and is used to test and obtain the fourth set of resistors.

[0084] A test port for a fifth set of resistors is formed between the first gasket 203a and the fourth gasket 203d and is used to test and obtain the fifth set of resistors.

[0085] A test port for a sixth set of resistors is formed between the second gasket 203b and the third gasket 203c and is used to test and obtain the sixth set of resistors.

[0086] In an embodiment of the present invention, the measured value of the active region resistance 201 is half of the difference obtained by subtracting the sum of the first set of resistors and the second set of resistors from the sum of the third set of resistors and the fourth set of resistors. In other embodiments, it can also be: the measured value of the active region resistance 201 is half of the difference obtained by subtracting the sum of the first set of resistors and the second set of resistors from the sum of the fifth set of resistors and the sixth set of resistors.

[0087] The first contact hole 202a, the second contact hole 202b, the third contact hole 202c, the fourth contact hole 202d, the first gasket 203a, the second gasket 203b, the third gasket 203c, and the fourth gasket 203d all have parasitic resistances, and the parasitic resistances of the first contact hole 202a, the second contact hole 202b, the third contact hole 202c, the fourth contact hole 202d, the first gasket 203a, the second gasket 203b, the third gasket 203c, and the fourth gasket 203d are eliminated in the measured value of the active region resistance 201. Figure 2Among them, the parasitic resistances of the first contact hole 202a, the second contact hole 202b, the third contact hole 202c, and the fourth contact hole 202d are represented by RC1, RC2, RC3, and RC4 respectively; the parasitic resistances of the first pad 203a, the second pad 203b, the third pad 203c, and the fourth pad 203d are the parasitic resistances of the connections between the first pad 203a, the second pad 203b, the third pad 203c, and the fourth pad 203d to the corresponding first contact hole 202a, second contact hole 202b, third contact hole 202c, and fourth contact hole 202d, and are represented by R1, R2, R3, and R4 respectively.

[0088] As Figure 3 shown, it is a formula derivation diagram of the measured value of the active region resistance in an embodiment of the present invention, including:

[0089] The formula for the first group of resistances is as shown in the dashed box 301 and is:

[0090] R 1-2 = R1 + RC1 + RC2 + R2 Formula (1);

[0091] The formula for the second group of resistances is as shown in the dashed box 303 and is:

[0092] R 3-4 = R3 + RC3 + RC4 + R4 Formula (2);

[0093] The formula for the third group of resistances is as shown in the dashed box 302 and is:

[0094] R 1-3 = R1 + RC1 + R + RC3 + R3 Formula (3);

[0095] The formula for the fourth group of resistances is as shown in the dashed box 304 and is:

[0096] R 2-4 = R2 + RC2 + R + RC4 + R4 Formula (4).

[0097] Among them, R 1-2 represents the first group of resistances, R 3-4 represents the second group of resistances, R 1-3 represents the third group of resistances, R 2-4 represents the fourth group of resistances;

[0098] R1 represents the parasitic resistance of the first pad 203a, R2 represents the parasitic resistance of the second pad 203b, R3 represents the parasitic resistance of the third pad 203c, and R4 represents the parasitic resistance of the fourth pad 203d;

[0099] RC1 represents the parasitic resistance of the first contact hole 202a, RC2 represents the parasitic resistance of the second contact hole 202b, RC3 represents the parasitic resistance of the third contact hole 202c, and RC4 represents the parasitic resistance of the fourth contact hole 202d;

[0100] R represents the active region resistance.

[0101] The above four groups of resistances can be obtained through measurement, and the active region resistance can be deduced from the measured four groups of resistances, that is, the measured value of the active region resistance can be obtained. It includes:

[0102] Figure 3 The dashed box 305 in the figure is the formula for the difference between the third group of resistances and the first group of resistances:

[0103] R 1-3 –R 1-2 = R + RC3 + R3 - RC2 - R2 Formula (5);

[0104] Figure 3 The dashed box 306 in the figure is the formula for the difference between the fourth group of resistances and the second group of resistances:

[0105] R 2-4 –R 3-4 = R + RC2 + R2 - RC3 - R3 Formula (6);

[0106] Figure 3 The dashed box 307 in the figure is the formula obtained by adding Formula (5) and Formula (6):

[0107] R 1-3 +R 2-4 -R 1-2 -R 3-4 = 2R Formula (7).

[0108] It can be seen from Formula (7) that the measured value of the active region resistance 201 is half of the difference obtained by subtracting the sum of the first group of resistances and the second group of resistances from the sum of the third group of resistances and the fourth group of resistances.

[0109] The sheet resistance of the active region resistance 201 can be obtained through the measured value of the active region resistance 201, and the formula is:

[0110] RS = (R 1-3 +R 2-4 -R 1-2 -R 3-4 ) / 2 * W / L Formula (8).

[0111] Wherein, W represents the width of the active region resistor 201, and L represents the length of the active region resistor 201. The final measurement result of the embodiment of the present invention is not affected by the test circuit resistance and the parasitic resistance RC of the contact hole (CT).

[0112] In the embodiment of the present invention, two contact holes and two pads are provided at both ends of the active region resistor 201. Up to six groups of test ports can be formed between the four pads and six groups of resistances can be obtained. The measured value of the active region resistor 201 without the parasitic resistance of the contact hole and the pad can be obtained by using the first to fourth groups of resistances or the first, second, fifth, and sixth groups of resistances. Therefore, the embodiment of the present invention can provide multiple groups of test ports and obtain the measured value of the active region resistor 201 through the test of multiple groups of test ports, and can eliminate the influence of the parasitic resistance of the contact hole and the connection line on the measured value of the active region resistor 201, thereby improving the measurement accuracy of the active region resistor.

[0113] The test method for the active region resistor in the embodiment of the present invention includes the following steps:

[0114] Step 1, forming a test structure, the test structure includes:

[0115] An active region resistor 201, which is composed of a doped region formed in the active region.

[0116] A first contact hole 202a and a second contact hole 202b are provided at the first end of the active region resistor 201.

[0117] A third contact hole 202c and a fourth contact hole 202d are provided at the second end of the active region resistor 201.

[0118] The first contact hole 202a is connected to the first pad 203a, the second contact hole 202b is connected to the second pad 203b, the third contact hole 202c is connected to the third pad 203c, and the fourth contact hole 202d is connected to the fourth pad 203d. Figure 2 In this case, the first pad 203a is also denoted as pad1, the second pad 203b is also denoted as pad2, the third pad 203c is also denoted as pad3, and the fourth pad 203d is also denoted as pad4.

[0119] In the method of the embodiment of the present invention, the active region is surrounded by field oxide formed in the semiconductor substrate.

[0120] The semiconductor substrate includes a silicon substrate.

[0121] The field oxide is shallow trench isolation or local field oxide.

[0122] The doped region of the active region resistor 201 is an N-type doped region or a P-type doped region.

[0123] An interlayer film is formed on the surface of the semiconductor substrate, and the first contact hole 202a, the second contact hole 202b, the third contact hole 202c, and the fourth contact hole 202d all penetrate through the interlayer film.

[0124] The first pad 203a, the second pad 203b, the third pad 203c, and the fourth pad 203d are all formed on the surface of the interlayer film.

[0125] The first contact hole 202a, the second contact hole 202b, the third contact hole 202c, the fourth contact hole 202d, the first pad 203a, the second pad 203b, the third pad 203c, and the fourth pad 203d all have parasitic resistances, and the parasitic resistances of the first contact hole 202a, the second contact hole 202b, the third contact hole 202c, the fourth contact hole 202d, the first pad 203a, the second pad 203b, the third pad 203c, and the fourth pad 203d are eliminated from the measured value of the active region resistance 201. Figure 2 Among them, the parasitic resistances of the first contact hole 202a, the second contact hole 202b, the third contact hole 202c, and the fourth contact hole 202d are represented by RC1, RC2, RC3, and RC4 respectively; the parasitic resistances of the first pad 203a, the second pad 203b, the third pad 203c, and the fourth pad 203d are the parasitic resistances of the connections between the first pad 203a, the second pad 203b, the third pad 203c, and the fourth pad 203d to the corresponding first contact hole 202a, the second contact hole 202b, the third contact hole 202c, and the fourth contact hole 202d, and are represented by R1, R2, R3, and R4 respectively.

[0126] Step 2: Perform a resistance test.

[0127] The resistance test includes:

[0128] Using the first pad 203a and the second pad 203b as two test ports to perform a test to obtain a first group of resistances;

[0129] Using the third pad 203c and the fourth pad 203d as two test ports to perform a test to obtain a second group of resistances;

[0130] Using the first pad 203a and the third pad 203c as two test ports to perform a test to obtain a third group of resistances;

[0131] Taking the second pad 203b and the fourth pad 203d as two test ports for testing to obtain the fourth group of resistances.

[0132] As Figure 3 shown, it is a formula derivation diagram of the measured values of the active region resistance in an embodiment of the present invention, including:

[0133] The formula for the first group of resistances is as shown in the dashed box 301 and is:

[0134] R 1-2 = R1 + RC1 + RC2 + R2 Formula (1);

[0135] The formula for the second group of resistances is as shown in the dashed box 303 and is:

[0136] R 3-4 = R3 + RC3 + RC4 + R4 Formula (2);

[0137] The formula for the third group of resistances is as shown in the dashed box 302 and is:

[0138] R 1-3 = R1 + RC1 + R + RC3 + R3 Formula (3);

[0139] The formula for the fourth group of resistances is as shown in the dashed box 304 and is:

[0140] R 2-4 = R2 + RC2 + R + RC4 + R4 Formula (4).

[0141] Among them, R 1-2 represents the first group of resistances, R 3-4 represents the second group of resistances, R 1-3 represents the third group of resistances, R 2-4 represents the fourth group of resistances;

[0142] R1 represents the parasitic resistance of the first pad 203a, R2 represents the parasitic resistance of the second pad 203b, R3 represents the parasitic resistance of the third pad 203c, and R4 represents the parasitic resistance of the fourth pad 203d;

[0143] RC1 represents the parasitic resistance of the first contact hole 202a, RC2 represents the parasitic resistance of the second contact hole 202b, RC3 represents the parasitic resistance of the third contact hole 202c, and RC4 represents the parasitic resistance of the fourth contact hole 202d;

[0144] R represents the active region resistance.

[0145] In other embodiment methods, it can also be: The resistance test includes:

[0146] Using the first gasket 203a and the second gasket 203b as two test ports to perform a test to obtain a first set of resistances;

[0147] Using the third gasket 203c and the fourth gasket 203d as two test ports to perform a test to obtain a second set of resistances;

[0148] Using the first gasket 203a and the fourth gasket 203d as two test ports to perform a test to obtain a fifth set of resistances;

[0149] Using the second gasket 203b and the third gasket 203c as two test ports to perform a test to obtain a sixth set of resistances.

[0150] Step Three: Calculate the measured value of the active region resistance 201.

[0151] The measured value of the active region resistance 201 is half of the difference obtained by subtracting the sum of the first set of resistances and the second set of resistances from the sum of the third set of resistances and the fourth set of resistances.

[0152] The measured value of the active region resistance can be derived from the four sets of measured resistances, that is, the measured value of the active region resistance is obtained. It includes:

[0153] Figure 3 The dashed box 305 in the figure is the formula for the difference between the third set of resistances and the first set of resistances:

[0154] R 1-3 –R 1-2 =R + RC3 + R3 - RC2 - R2 Formula (5);

[0155] Figure 3 The dashed box 306 in the figure is the formula for the difference between the fourth set of resistances and the second set of resistances:

[0156] R 2-4 –R 3-4 =R + RC2 + R2 - RC3 - R3 Formula (6);

[0157] Figure 3 The dashed box 307 in the figure is the formula obtained by adding Formula (5) and Formula (6):

[0158] R 1-3 +R 2-4 -R 1-2 -R 3-4 =2R Formula (7).

[0159] It can be seen from Formula (7) that the measured value of the active region resistance 201 is half of the difference obtained by subtracting the sum of the first set of resistances and the second set of resistances from the sum of the third set of resistances and the fourth set of resistances.

[0160] In other embodiment methods, it can also be: the measured value of the active region resistance 201 is half of the difference obtained by subtracting the sum of the first group of resistors and the second group of resistors from the sum of the fifth group of resistors and the sixth group of resistors.

[0161] It further includes: Step Four, calculating the sheet resistance of the active region resistance 201.

[0162] The sheet resistance of the active region resistance 201 is the measured value of the active region resistance 201 multiplied by the ratio of the width and length of the active region resistance 201. The calculation formula for the sheet resistance of the active region resistance 201 is:

[0163] RS = (R 1-3 + R 2-4 - R 1-2 - R 3-4 ) / 2 * W / L Formula (8).

[0164] Wherein, RS represents the sheet resistance of the active region resistance 201, W represents the width of the active region resistance 201, and L represents the length of the active region resistance 201. The final measurement result of the embodiment of the present invention is not affected by the resistance of the test circuit and the parasitic resistance RC of the contact hole (CT).

[0165] The present invention has been described in detail through specific embodiments above, but these do not constitute limitations on the present invention. Without departing from the principle of the present invention, those skilled in the art can also make many deformations and improvements, which should also be regarded as the protection scope of the present invention.

Claims

1. A test structure for an active region resistor, characterized in that, Comprising: An active region resistor, which is composed of a doped region formed in the active region; A first contact hole and a second contact hole are provided at the first end of the active region resistor; A third contact hole and a fourth contact hole are provided at the second end of the active region resistor; The first contact hole is connected to a first pad, the second contact hole is connected to a second pad, the third contact hole is connected to a third pad, and the fourth contact hole is connected to a fourth pad; A test port for a first group of resistors is formed between the first pad and the second pad and is used to test and obtain the first group of resistors; A test port for a second group of resistors is formed between the third pad and the fourth pad and is used to test and obtain the second group of resistors; A test port for a third group of resistors is formed between the first pad and the third pad and is used to test and obtain the third group of resistors; A test port for a fourth group of resistors is formed between the second pad and the fourth pad and is used to test and obtain the fourth group of resistors; A test port for a fifth group of resistors is formed between the first pad and the fourth pad and is used to test and obtain the fifth group of resistors; A test port for a sixth group of resistors is formed between the second pad and the third pad and is used to test and obtain the sixth group of resistors; The measured value of the active region resistor is half of the difference obtained by subtracting the sum of the first group of resistors and the second group of resistors from the sum of the third group of resistors and the fourth group of resistors; alternatively, the measured value of the active region resistor is half of the difference obtained by subtracting the sum of the first group of resistors and the second group of resistors from the sum of the fifth group of resistors and the sixth group of resistors.

2. The test structure of the active region resistance according to claim 1, wherein: The active region is surrounded by field oxide formed in the semiconductor substrate.

3. The test structure of the active region resistance according to claim 2, wherein: The semiconductor substrate includes a silicon substrate.

4. The test structure of the active region resistance according to claim 2, wherein: The field oxide is shallow trench isolation or local field oxide.

5. The test structure of the active region resistance according to claim 2, characterized in that: The doped region of the active region resistor is an N-type doped region or a P-type doped region.

6. The test structure of the active region resistance according to claim 1, wherein: The first contact hole, the second contact hole, the third contact hole, the fourth contact hole, the first pad, the second pad, the third pad, and the fourth pad all have parasitic resistances, and the parasitic resistances of the first contact hole, the second contact hole, the third contact hole, the fourth contact hole, the first pad, the second pad, the third pad, and the fourth pad are eliminated in the measured value of the active region resistor.

7. The test structure of the active region resistance according to claim 2, wherein: An interlayer film is formed on the surface of the semiconductor substrate, and the first contact hole, the second contact hole, the third contact hole, and the fourth contact hole all pass through the interlayer film; The first pad, the second pad, the third pad, and the fourth pad are all formed on the surface of the interlayer film.

8. A method for testing the resistance of an active region, characterized in that, Including the following steps: Step 1, forming a test structure, the test structure includes: An active region resistor, which is composed of a doped region formed in the active region; A first contact hole and a second contact hole are provided at the first end of the active region resistor; A third contact hole and a fourth contact hole are provided at the second end of the active region resistor; The first contact hole is connected to a first pad, the second contact hole is connected to a second pad, the third contact hole is connected to a third pad, and the fourth contact hole is connected to a fourth pad; Step 2: Conduct a resistance test; The resistance test includes: Using the first pad and the second pad as two test ports to conduct a test to obtain a first set of resistances; Using the third pad and the fourth pad as two test ports to conduct a test to obtain a second set of resistances; Using the first pad and the third pad as two test ports to conduct a test to obtain a third set of resistances; Using the second pad and the fourth pad as two test ports to conduct a test to obtain a fourth set of resistances; Alternatively, the resistance test includes: Using the first pad and the second pad as two test ports to conduct a test to obtain a first set of resistances; Using the third pad and the fourth pad as two test ports to conduct a test to obtain a second set of resistances; Using the first pad and the fourth pad as two test ports to conduct a test to obtain a fifth set of resistances; Using the second pad and the third pad as two test ports to conduct a test to obtain a sixth set of resistances; Step 3: Calculate the measured value of the active region resistance; The measured value of the active region resistance is half of the difference obtained by subtracting the sum of the first set of resistances and the second set of resistances from the sum of the third set of resistances and the fourth set of resistances; Alternatively, the measured value of the active region resistance is half of the difference obtained by subtracting the sum of the first set of resistances and the second set of resistances from the sum of the fifth set of resistances and the sixth set of resistances.

9. The method for testing the resistance of the active region according to claim 8, wherein: The active region is surrounded by field oxide formed in a semiconductor substrate.

10. The method for testing the resistance of the active region according to claim 9, wherein: The semiconductor substrate includes a silicon substrate.

11. The method for testing the resistance of the active region according to claim 9, wherein: The field oxide is shallow trench isolation or local field oxide.

12. The method for testing the resistance of the active region according to claim 9, wherein: The doped region of the active region resistance is an N-type doped region or a P-type doped region.

13. The method for testing the resistance of the active region according to claim 8, wherein: The first contact hole, the second contact hole, the third contact hole, the fourth contact hole, the first pad, the second pad, the third pad, and the fourth pad all have parasitic resistances, and the parasitic resistances of the first contact hole, the second contact hole, the third contact hole, the fourth contact hole, the first pad, the second pad, the third pad, and the fourth pad are eliminated in the measured value of the active region resistance.

14. The method for testing the resistance of the active region according to claim 9, wherein: An interlayer film is formed on the surface of the semiconductor substrate, and the first contact hole, the second contact hole, the third contact hole, and the fourth contact hole all pass through the interlayer film; The first pad, the second pad, the third pad, and the fourth pad are all formed on the surface of the interlayer film.

15. The method for testing the resistance of the active region according to claim 8, wherein: It further includes: Step 4: Calculate the sheet resistance of the active region resistance; The sheet resistance of the active region resistance is the measured value of the active region resistance multiplied by the ratio of the width and length of the active region resistance.

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