Test circuit and test equipment

Abstract

The invention relates to a test circuit and test equipment, the test circuit is used for performing an electrical test on a semiconductor test structure, the semiconductor test structure comprises a plurality of transistors to be tested, the test circuit comprises a first voltage control module and a second voltage control module, the first voltage control module comprises a high-resistance end, and the second voltage control module comprises a high-resistance end. The high-resistance end is used for being connected with the first test pad corresponding to the first body end of each transistor to be tested so as to output test voltage to the first body end of each transistor to be tested, and the second voltage control module comprises a plurality of mutually independent voltage supply ends in one-to-one correspondence with the plurality of transistors to be tested; the voltage supply end is used for being connected with the second test pad corresponding to the gate end of the corresponding transistor to be tested so as to form detection current on the corresponding transistor to be tested. The test circuit disclosed by the invention can effectively shorten the evaluation period of the voltage acceleration factor of each transistor to be tested so as to improve the technological process efficiency of the semiconductor structure.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor testing, and in particular to a testing circuit and a testing device. Background Art

[0002] In the process of manufacturing semiconductor devices, it is usually necessary to integrate a test element group (TEG) including a semiconductor test structure with multiple transistors to be tested into the semiconductor device, and perform a time-dependent dielectric breakdown (TDDB) test on the transistors to be tested through multiple test circuits in a test machine to evaluate the voltage acceleration factor of the semiconductor test structure. However, the existing test process has low test efficiency, which affects the product development cycle. Summary of the invention

[0003] In order to overcome the problems existing in the related art, the present disclosure provides a test circuit and a test device.

[0004] According to a first aspect of an embodiment of the present disclosure, a test circuit is provided for performing an electrical test on a semiconductor test structure, wherein the semiconductor test structure includes a plurality of transistors to be tested, and the test circuit includes:

[0005] A first voltage control module, the first voltage control module comprising a high resistance end, the high resistance end being used to be connected to first test pads corresponding to the first body end of each of the transistors to be tested, so as to output a test voltage to the first body end of each of the transistors to be tested;

[0006] A second voltage control module, the second voltage control module includes a plurality of independent voltage supply terminals corresponding one by one to the plurality of transistors to be tested, the voltage supply terminals are used to be connected to second test pads corresponding to the gate terminals of the corresponding transistors to be tested to form a detection current on the corresponding transistors to be tested.

[0007] In some embodiments of the present disclosure, among the multiple voltage supply terminals, one of the voltage supply terminals is connected to a common ground terminal.

[0008] In some embodiments of the present disclosure, the second voltage control module also includes an operation unit connected to at least one of the voltage supply terminals, a first input terminal of the operation unit is coupled to the high-resistance terminal, a second input terminal of the operation unit is connected to a first voltage generating unit, and an output terminal of the operation unit constitutes one of the voltage supply terminals.

[0009] In some embodiments of the present disclosure, the operation unit includes an adder, a subtractor, a multiplier or a divider.

[0010] In some embodiments of the present disclosure, the second voltage control module includes a computing unit respectively connected to different voltage supply terminals;

[0011] Different computing units are connected to different first voltage generating units, or,

[0012] Different operation units are connected to the same first voltage generating unit, and the first voltage generating unit is used to provide different voltage signals to different operation units.

[0013] In some embodiments of the present disclosure, the first voltage control module includes a voltage control unit and a second voltage generating unit, one end of the voltage control unit constitutes the high-resistance end, and the other end of the voltage control unit is coupled to the output end of the second voltage generating unit.

[0014] In some embodiments of the present disclosure, the voltage control unit includes a voltage follower, an output end of the voltage follower is coupled to an output end of the second voltage generating unit, and an input end of the voltage follower constitutes the high-resistance end.

[0015] In some embodiments of the present disclosure, the voltage follower includes a first operational amplifier, a first input terminal of the first operational amplifier constitutes the high-impedance terminal, a second input terminal of the first operational amplifier is coupled to an output terminal of the first operational amplifier, and an output terminal of the first operational amplifier is coupled to an output terminal of the second voltage generating unit.

[0016] In some embodiments of the present disclosure, the test circuit also includes a second operational amplifier, a first input terminal of the second operational amplifier is coupled to the output terminal of the second voltage generating unit, and the output terminal of the second operational amplifier is used to connect to the third test pads corresponding to the second body terminal, source terminal, and drain terminal of each of the transistors to be tested.

[0017] According to a second aspect of an embodiment of the present disclosure, a testing device is provided, the testing device comprising the testing circuit as described in the first aspect, the testing device further comprising a first testing probe and a second testing probe corresponding one-to-one to each of the transistors to be tested, the first testing probe being used to contact the first testing pad, and the second testing probe being used to contact the second testing pad of the corresponding transistor to be tested.

[0018] The disclosed embodiment has at least the following beneficial effects: the test circuit ensures that the voltage input to the first body terminal of the transistor to be tested is always the test voltage by setting a first voltage control module including a high-resistance terminal, thereby preventing the ohmic potential drop caused by other resistance values ​​of the transistor to be tested other than the impedance from interfering with the set test voltage. Since the voltage value of the test voltage connected to the first body terminal and the voltage value of the output voltage of the relatively independent voltage supply terminal are both constant voltages, the voltage difference applied to the two ends of each transistor to be tested is always in a stable state, thereby preventing the voltage of the gate terminal of other transistors to be tested from being affected when a certain transistor to be tested has a breakdown phenomenon, so that multiple transistors to be tested can be tested simultaneously, effectively shortening the evaluation cycle of the voltage acceleration factor of each transistor to be tested, so as to improve the process efficiency of the semiconductor structure.

[0019] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0021] Figure 1 It is an equivalent circuit diagram of a test circuit and a transistor to be tested in the prior art.

[0022] Figure 2 An equivalent circuit diagram of a test circuit and a transistor to be tested according to an exemplary embodiment of the present disclosure is shown.

[0023] Figure 3 A schematic diagram of a structure of a transistor to be tested disposed on a substrate according to an exemplary embodiment of the present disclosure

[0024] Figure 4 The figure is an equivalent circuit diagram of a high-resistance terminal, a current control terminal and a transistor to be tested according to an exemplary embodiment of the present disclosure.

[0025] Figure 5 The figure is an equivalent circuit diagram of a high-resistance terminal, a first signal generator, a voltage supply terminal and a transistor to be tested according to an exemplary embodiment of the present disclosure.

[0026] Figure 6 This is a schematic diagram of a sinusoidal waveform with a constant slope and a constant offset according to an exemplary embodiment of the present disclosure.

[0027] Figure 7 It is a schematic diagram of a medium slope waveform in the prior art.

[0028] Figure 8 It is a schematic diagram of a sinusoidal waveform in the prior art.

[0029] Fig. 9 It is a schematic diagram of a constant offset waveform in the prior art.

[0030] Description of reference numerals:

[0031] This application:

[0032] 10-test circuit; 20-first voltage control module; 21-high resistance terminal; 30-voltage control unit; 31-voltage follower; 32-resistance inductor; 33-first operational amplifier; 40-second voltage generating unit; 41-second signal generator; 50-current control module; 51-current control terminal; 52-second operational amplifier; 61-first test pad; 62-second test pad; 70-transistor to be tested; 71-first body terminal; 72-second body terminal; 73-source terminal; 74-drain terminal; 75-gate terminal; 76-gate oxide layer; 77-liner Bottom; 81-capacitor structure; 82-first equivalent resistor; 83-second equivalent resistor; 84-third equivalent resistor; 91-first end; 92-second end; 100-second voltage control module; 110-voltage supply end; 111-first voltage supply end; 112-second voltage supply end; 113-third voltage supply end; 120-operation unit; 121-first operation unit; 122-second operation unit; 200-first voltage generating unit; 210-first signal generator; 211-first signal generating unit; 212-second signal generating unit.

[0033] Related technologies:

[0034] 81'-capacitor structure. DETAILED DESCRIPTION

[0035] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0036] In the related art, when manufacturing a semiconductor device, it is usually necessary to integrate a test element group (TEG) including a semiconductor test structure having multiple transistors to be tested into the semiconductor device, and perform a time dependent dielectric breakdown (TDDB) test on the transistors to be tested through multiple groups of test circuits in a test machine to evaluate the voltage acceleration factor of the semiconductor test structure.

[0037] When the semiconductor test structure is electrically tested through the existing test circuit, a test voltage is usually applied to the gate of the transistor to be tested for TDDB testing. This test method requires testing each transistor to be tested separately, and only one test can be performed on one transistor to be tested at a time. For different transistors to be tested, the test voltage needs to be applied to each transistor to be tested multiple times, resulting in a too long evaluation cycle of the voltage acceleration factor of the semiconductor test structure, causing low process efficiency of the semiconductor structure, thus affecting the product development cycle. If the test voltage is applied to multiple transistors to be tested at the same time during a test, the test circuit can be equivalent to Figure 1 The circuit shown in FIG. 8 is a circuit in which a capacitor structure 81' is an equivalent capacitor of a transistor to be tested, one end of the capacitor structure 81' is a test voltage application end, and the other end of the capacitor structure 81' is a common ground end. Since the other ends of the capacitor structures 81' of the transistors to be tested are connected to the common ground end, when one of the transistors to be tested breaks down, the voltage at the common ground end of the capacitor structure 81' will change. Therefore, the actual voltage applied to the other transistors to be tested will deviate from the test voltage, resulting in an inaccurate evaluation result of the final voltage acceleration factor and errors in the capacitor structure 81' test structure.

[0038] Based on this, the exemplary embodiment of the present disclosure provides a test circuit and a test device, wherein the test circuit ensures that the voltage input to the first body terminal of the transistor to be tested is always the test voltage by setting a voltage control module including a high-resistance terminal, so as to avoid the ohmic potential drop caused by other resistance values ​​of the transistor to be tested other than the impedance from interfering with the set test voltage. Since the voltage value of the test voltage connected to the first body terminal and the voltage value of the output voltage of the relatively independent voltage supply terminal are both constant voltages, the voltage difference applied to the two ends of each transistor to be tested is always in a stable state, so as to avoid the influence of the voltage of the gate terminal of other transistors to be tested when a certain transistor to be tested has a breakdown phenomenon, so that multiple transistors to be tested can be tested at the same time, effectively shortening the evaluation cycle of the voltage acceleration factor of each transistor to be tested, so as to improve the process efficiency of the semiconductor structure.

[0039] In an exemplary embodiment, Figures 2 to 5 As shown, a test circuit is provided for performing electrical testing on a semiconductor test structure. The semiconductor test structure includes a plurality of transistors 70 to be tested. The transistors 70 to be tested may be triodes, for example. The plurality of semiconductor test structures may form a test element group (TEG) in a semiconductor device.

[0040] The test circuit 10 includes a first voltage control module 20 and a second voltage control module 100. The first voltage control module 20 includes a high resistance terminal 21, and the high resistance terminal 21 is used to be connected to the first test pad 61 corresponding to the first body terminal 71 of each transistor under test 70, so as to output a test voltage to the first body terminal 71 of each transistor under test 70. The second voltage control module 100 includes a plurality of independent voltage supply terminals 110 corresponding to the plurality of transistors under test 70 one by one, and the voltage supply terminal 110 is used to be connected to the second test pad 62 corresponding to the gate terminal 75 of the corresponding transistor under test 70, so as to form a detection current on the corresponding transistor under test 70.

[0041] Among them, reference Figure 2 Since the high resistance end 21 of the first voltage control module 20 has a high resistance value, the circuit where the high resistance end 21 is located can be considered to be in an open circuit state and no current flows through it, so as to avoid the current flowing through the resistance at the first body end 71 causing the change of the ohmic potential drop and making the actual voltage at the first body end 71 less than the test voltage output by the first voltage control module 20, that is, the voltage of the first body end 71 is controlled by the first voltage control module 20, so that the actual voltage value at the first body end 71 is the set test voltage value. Since each voltage supply end 110 is independent of each other, each voltage supply end 110 will not affect each other. Therefore, even if the transistor 70 to be tested breaks down, the test voltage of other transistors 70 to be tested connected to the first body end 71 will not change, and the voltage of the gate end 75 of other transistors 70 to be tested will not change. Therefore, during the test process, the voltage difference between the two ends of each transistor 70 to be tested can always be in a stable state and will not be affected by other transistors 70 to be tested.

[0042] For example, reference Figure 3 The transistor 70 to be tested is arranged on a substrate 77, and includes a first body terminal 71, a second body terminal 72, a source terminal 73, a drain terminal 74, a gate terminal 75 and a gate oxide layer 76, wherein the doping type of the substrate 77, the first body terminal 71 and the second body terminal 72 is a first doping type, and the doping concentration of the first body terminal 71 and the second body terminal 72 is greater than the doping concentration of the substrate 77. The doping type of the source terminal 73 (i.e., the source region in the active region) and the drain terminal 74 (i.e., the drain region in the active region) is a second doping type. The first doping type is different from the second doping type. For example, when the first doping type is P-type doping, the second doping type is N-type doping, and when the first doping type is N-type doping, the second doping type is P-type doping. The source terminal 73 and the drain terminal 74, for example, can be a P+ type or N+ type doping region arranged on the substrate 77, and the first body terminal 71 and the second body terminal 72 can, for example, be arranged in different regions on the substrate 77.

[0043] For example, Figure 4As shown, the gate terminal 75 of the transistor to be tested 70 and the gate oxide layer 76 form a first capacitor, and the channel between the source terminal 73 and the drain terminal 74 and the gate oxide layer 76 form a second capacitor. The first capacitor and the second capacitor constitute Figure 4 The capacitor structure 81 shown in the figure has a certain impedance value. In addition to the capacitor structure 81, the high-resistance end 21 and the common ground terminal also pass through the interconnection line, the contact plug, the first body terminal 71 and other structures. Therefore, the high-resistance end 21 and the common ground terminal also have a first equivalent resistor 82 formed by the interconnection line, the contact plug, the first body terminal 71 and other structures. The first equivalent resistor 82 has a first resistance value. The first voltage control module 20 can output a test voltage to the first body terminal 71. Since the high-resistance end 21 is connected to the first body terminal 71, no current will flow through the first equivalent resistor 82, and the first equivalent resistor 82 will not have an ohmic drop problem. When the TDDB test is performed on the transistor 70 to be tested, for example, it can be determined whether the capacitor structure 81 of each transistor 70 to be tested is broken down by detecting the current flowing through the transistor 70 to be tested, and the breakdown life of each transistor 70 to be tested is collected, and the Weibull distribution of the life is made according to the voltage to obtain the voltage acceleration factor.

[0044] In this embodiment, by setting a first voltage control module 20 including a high resistance terminal 21, it is ensured that the voltage input to the first body terminal 71 of the transistor to be tested 70 is always the test voltage, and the ohmic potential drop caused by other resistance values ​​of the transistor to be tested 70 other than the impedance is prevented from interfering with the set test voltage. Since the test voltage value connected to the first body terminal 71 and the voltage value of the output voltage of the relatively independent voltage supply terminal 110 are both constant voltages, the voltage difference applied to both ends of each transistor to be tested 70 is always in a stable state, and the voltage of the gate terminal 75 of other transistors to be tested 70 is prevented from being affected when a certain transistor to be tested 70 breaks down. Therefore, multiple transistors to be tested 70 can be tested at the same time, effectively shortening the evaluation cycle of the voltage acceleration factor of each transistor to be tested 70, so as to improve the process efficiency of the semiconductor structure.

[0045] In an exemplary embodiment of the present disclosure, Figure 2 As shown, the test circuit 10 also includes a current control module 50, which is coupled to the first voltage control module 20. The current control module 50 includes a current control terminal 51, and the current control terminal 51 is used to connect to the second test pad 62 corresponding to the second body terminal 72, the source terminal 73, and the drain terminal 74 of the transistor 70 to be tested, so as to control the current flowing through the transistor 70 to be tested.

[0046] Among them, the current control module 50 is coupled to the first voltage control module 20, and the current control terminal 51 of the current control module 50 is connected to the second test pad 62 corresponding to the second body terminal 72, source terminal 73, and drain terminal 74 of the transistor under test 70 to control the current flowing through the transistor under test 70.

[0047] In addition to the capacitor structure 81, the current control terminal 51 and the common ground terminal also pass through interconnection lines, contact plugs, the second body terminal 72, the source terminal 73, the drain terminal 74 and other structures. Therefore, the current control terminal 51 and the common ground terminal also have a second equivalent resistor 83 formed by structures including interconnection lines, contact plugs, the source terminal 73, the drain terminal 74, the second body terminal 72 and other structures. The second equivalent resistor 83 has a second resistance value. The current control module 50 can control the current flowing through the transistor 70 to be tested from the current control terminal 51, that is, control the current flowing through the second equivalent resistor 83 to be the same as the current at the capacitor structure 81, so that the second equivalent resistor 83 of the transistor 70 to be tested and the current in the capacitor structure 81 as a response signal are the same. It should be noted that Figure 2 The first equivalent resistor 82, the second equivalent resistor 83 and the capacitor structure 81 in the embodiment have the same meaning as Figure 4 The first equivalent resistor 82, the second equivalent resistor 83 and the capacitor structure 81 have the same meaning.

[0048] In this embodiment, by setting up a current control module 50 including a current control terminal 51, the current flowing through the second body terminal 72, the source terminal 73 and the drain terminal 74 of the transistor to be tested 70 can be controlled. Through the joint action of the first voltage control module 20 and the current control module 50, the ohmic potential drop caused by other resistances of the transistor to be tested 70 except the impedance of the capacitor structure 81 can be avoided to interfere with the set test voltage, thereby eliminating test errors and improving test accuracy.

[0049] In some embodiments, continue to refer to Figure 2 Among the multiple voltage supply terminals 110, one of the voltage supply terminals 110 is connected to the common ground terminal.

[0050] Exemplarily, the test voltage output by the first voltage control module 20 may be e(t), which is connected to the common ground terminal through the voltage supply terminal 110. The voltage supply terminal 110 may provide a reference voltage to the gate terminal 75 of the transistor to be tested 70. The reference voltage may be 0, for example. That is, the voltage provided by the voltage supply terminal 110 to the transistor to be tested is 0. At this time, the voltage across the transistor to be tested 70 connected to the voltage supply terminal 110 is e(t).

[0051] In this embodiment, by connecting the gate terminal 75 of one of the transistors to be tested 70 to the common ground terminal, and providing a reference voltage for the gate terminal 75 of the transistor to be tested 70 through the common ground terminal, and outputting a stable test voltage to the first body terminal 71 of the transistor to be tested 70 through the first voltage control module 20, it can be ensured that the voltage difference applied across the transistor to be tested 70 in this embodiment is always in a stable state, thereby ensuring the accuracy of the evaluation result of the voltage acceleration factor. On the other hand, using the common ground terminal as the voltage supply terminal 110 of the transistor to be tested 70 can simplify the circuit arrangement and circuit layout of the test circuit 10, and save the overall construction cost of the test circuit 10.

[0052] In some embodiments, Figure 2 As shown, the second voltage control module 100 also includes an operation unit 120 connected to at least one voltage supply terminal 110, a first input terminal of the operation unit 120 is coupled to the high resistance terminal 21, a second input terminal of the operation unit 120 is connected to the first voltage generating unit 200, and an output terminal of the operation unit 120 constitutes a voltage supply terminal 110.

[0053] Exemplarily, the input voltages of the first input terminal and the second input terminal of the operation unit 120 may be the same or different, that is, the output voltage signal of the first voltage generating unit 200 and the test voltage signal output by the first voltage control module 20 may be the same or different, and the operation unit 120 may perform mathematical operations such as addition, subtraction, differentiation, integration, etc. according to the above-mentioned output voltage signal and the test voltage signal, and output the operation result in the form of a signal.

[0054] When the voltage value required to be applied to each transistor 70 under test is a value other than e(t), an operation unit 120 can be set on the voltage supply terminal 110, and the output voltage of the output terminal of the operation unit 120 can be adjusted. The difference between the output voltage and the test voltage is the voltage value applied to both ends of the transistor 70 under test.

[0055] In this embodiment, since the voltage output by the high-resistance terminal 21 is always a constant test voltage, by inputting the test voltage to the first input terminal of the operation unit 120 and inputting the preset input voltage to the second input terminal of the operation unit 120, the input voltage applied to the gate terminal 75 of the transistor to be tested 70 can be directly obtained through logical operation. Since the input voltage of the first body terminal 71 of the transistor to be tested 70 is the test voltage, the voltage applied to the transistor to be tested 70 is the voltage difference between the gate terminal 75 and the first body terminal 71. The voltage difference is convenient, controllable and easy to obtain, which improves the accuracy and convenience of evaluating the voltage acceleration factor of the semiconductor test structure.

[0056] In some embodiments, Figure 2As shown, the second voltage control module 100 includes a first voltage supply terminal 111, a second voltage supply terminal 112 and a third voltage supply terminal 113, the operation unit 120 includes a first operation unit 121 and a second operation unit 122, and the first signal generator 210 includes a first signal generating unit 211 coupled to the first operation unit 121 and a second signal generating unit 212 coupled to the second operation unit 122, wherein the output terminal of the first operation unit 121 constitutes the first voltage supply terminal 111, the output terminal of the second operation unit 122 constitutes the second voltage supply terminal 112, and the third voltage supply terminal 113 is coupled to the common ground terminal.

[0057] Exemplarily, both the first operation unit 121 and the second operation unit 122 can be adders, wherein the output voltage signal of the first signal generating unit 211 can be, for example, e1(t), that is, the input voltage of the second input terminal of the first operation unit 121 can be e1(t), and the input voltage of the first input terminal of the first operation unit 121 is a test voltage signal, for example, e(t) described above, therefore, the voltage difference finally applied to both ends of the transistor 70 to be tested is the output voltage signal of the first signal generating unit 211, for example, e1(t) described above. The output voltage signal of the second operation unit 122 can be, for example, e2(t), that is, the input voltage of the second input terminal of the second operation unit 122 can be e2(t), and the input voltage of the first input terminal of the second operation unit 122 is a test voltage signal, for example, e(t) described above, therefore, the voltage difference finally applied to both ends of the transistor 70 to be tested is the output voltage signal of the second signal generating unit 212, for example, e2(t) described above.

[0058] In this embodiment, by coupling the gate terminal 75 of the transistor 70 to be tested corresponding to the third voltage supply terminal 113 to the common ground terminal, and outputting a stable test voltage to the first body terminal 71 of the transistor 70 to be tested through the first voltage control module 20, it is possible to ensure that both ends of the transistor 70 to be tested are always in a stable state while simplifying the circuit layout of the test circuit 10, thereby improving the accuracy of the evaluation result of the voltage acceleration factor of the transistor 70 to be tested. Since the voltage value input to the first body terminal 71 of all the transistors 70 to be tested is always in a stable state, different voltage signals are output to the two groups of transistors 70 to be tested respectively by the first operation unit 121 and the second operation unit 122 which are independent of each other, so that different voltages can be applied to both ends of different transistors 70 to be tested, and targeted testing of the transistor 70 to be tested is achieved, so as to improve the accuracy of the voltage acceleration factor of the transistor 70 to be tested.

[0059] In some embodiments, the operation unit 120 includes an adder, a subtractor, a multiplier, or a divider.

[0060] Exemplarily, the adder may include a half adder or a full adder. When the adder is a half adder, the adder may be used to output the addition result and the carry result of the output voltage of the first voltage generating unit 200 and the test voltage output by the first voltage control module 20. When the adder is a full adder, the adder may be used to output the operation value of the addition result and the carry result of the output voltage of the first voltage generating unit 200 and the test voltage output by the first voltage control module 20.

[0061] The subtractor can perform a subtraction operation, and the subtractor can include a half subtractor and a full subtractor. When the subtractor is a half subtractor, the subtractor can be used to output the subtraction result and the borrow result of the output voltage of the first voltage generating unit 200 and the test voltage output by the first voltage control module 20. When the subtractor is a full subtractor, the subtractor can be used to output the subtraction result and the borrow result of the output voltage of the first voltage generating unit 200 and the test voltage output by the first voltage control module 20.

[0062] The multiplier can perform multiplication operations and can be used to output the multiplication results of the output voltage of the first voltage generating unit 200 and the test voltage output by the first voltage control module 20. When the operation unit 120 is a multiplier, the multiplier can include a parallel multiplier, a running multiplier, etc.

[0063] The divider may be used to perform a division operation. When the operation unit 120 is a divider, the divider may be used to output a quotient and a remainder of the output voltage of the first voltage generating unit 200 and the test voltage output by the first voltage control module 20 .

[0064] In this embodiment, the output voltage output by the first voltage generating unit 200 and the output voltage of the test voltage output by the first voltage control module 20 under the action of the operation unit 120 can be obtained through an adder or a subtractor or a multiplier or a divider. The output voltage can be directly obtained through a corresponding logical operation method. By coupling the output end of the operation unit 120 with the gate end 75 of the transistor 70 to be tested, and coupling the high-resistance end 21 of the first voltage control module 20 with the first body end 71, the voltage difference on both sides of the transistor 70 to be tested can be directly applied. The voltage difference is convenient, controllable and easy to obtain, which improves the accuracy and convenience of evaluating the voltage acceleration factor of the semiconductor test structure.

[0065] In some embodiments, Figure 2 As shown, the second voltage control module 100 includes operation units 120 respectively connected to different voltage supply terminals 110 , and different operation units 120 are correspondingly connected to different first voltage generating units 200 .

[0066] Exemplarily, the first voltage generating unit 200 may include a first signal generator 210 (function generator) capable of generating different types of waveform signals to output a test voltage having a preset waveform, such as a sine wave, a triangle wave, a square wave, etc.

[0067] One end of the first signal generator 210 is, for example, a ground end, and the ground end of the first signal generator 210 is coupled to the common ground end to provide an accurate reference signal. The other end of the first signal generator 210 is, for example, an output end, and the output end of the first signal generator 210 constitutes a second input end of the operation unit 120.

[0068] In this embodiment, a plurality of different first voltage generating units 200 are used to input voltages to each operation unit 120, respectively, and it is ensured that each output voltage does not affect each other, thereby ensuring the stability of the input voltage at the second input end of the operation unit 120, so as to eliminate test errors and improve test accuracy. The provision of a plurality of different first voltage generating units 200 facilitates the control of the output voltage value of each operation unit 120, thereby facilitating the loading of different voltages at both ends of different transistors to be tested 70, and realizing differentiated testing of different transistors to be tested 70.

[0069] In other embodiments, the second voltage control module 100 includes operation units 120 respectively connected to different voltage supply terminals 110 , and different operation units 120 are connected to the same first voltage generating unit 200 , and the first voltage generating unit 200 is used to provide different voltage signals to different operation units 120 .

[0070] In this embodiment, by connecting the operation unit 120 to the same first voltage generating unit 200, the voltage can be output to each operation unit 120 at the same time through the first voltage generating unit 200, so that the start time of each TDDB test is consistent, and when the capacitor structure 81 of the subsequent semiconductor test structure produces a breakdown phenomenon, the start time can be used as a reference value, thereby improving the accuracy of the cycle of evaluating the voltage acceleration factor of each transistor under test 70. By outputting voltage to each operation unit 120 through a single first voltage generating unit 200, the number of first voltage generating units 200 assembled can be reduced, the overall construction cost of the test circuit 10 can be saved, and the overall layout of the circuit can be optimized.

[0071] In some embodiments, the first voltage control module 20 includes a voltage control unit 30 and a second voltage generating unit 40 , one end of the voltage control unit 30 forms a high impedance end 21 , and the other end of the voltage control unit 30 is coupled to the output end of the second voltage generating unit 40 .

[0072] Among them, Figure 2As shown, the first voltage control module 20 includes a voltage control unit 30 and a second voltage generating unit 40, and the second voltage generating unit 40 can output a test voltage through the output terminal of the second voltage generating unit 40. The first terminal 91 of the voltage control unit 30 constitutes the high-resistance terminal 21 of the first voltage control module 20, and the second terminal 92 of the voltage control unit 30 is coupled to the output terminal of the second voltage generating unit 40, so that the voltage at the second terminal 92 of the voltage control unit 30 is the test voltage output by the output terminal of the second voltage generating unit 40, and the voltage at the first terminal 91 of the voltage control unit 30 is the same as the voltage at the second terminal 92 through the control action of the voltage control unit 30, that is, the voltage at the high-resistance terminal 21 is the test voltage output by the second voltage generating unit 40.

[0073] In this embodiment, by setting the second voltage generating unit 40, the test voltage can be output from the output end of the second voltage generating unit 40, and by setting the voltage control unit 30, the voltage at the first end 91 of the voltage control unit 30 can be controlled to be the same as the voltage at the second end 92, and the second end 92 of the voltage control unit 30 is coupled to the output end of the second voltage generating unit 40, thereby achieving the function of outputting the test voltage to the first body terminal 71 of the transistor to be tested 70 through the first voltage control module 20 composed of the voltage control unit 30 and the second voltage generating unit 40, so that the actual voltage of the first body terminal 71 is the set test voltage, thereby eliminating the error in the test result caused by the difference between the actual voltage and the set test voltage, and improving the test accuracy.

[0074] In some embodiments, Figure 2 As shown, the voltage control unit 30 includes a voltage follower 31 , the output end of the voltage follower 31 is coupled to the output end of the second voltage generating unit 40 , and the input end of the voltage follower 31 constitutes the high impedance end 21 .

[0075] Among them, the voltage follower 31 is also called a unity gain amplifier, a buffer amplifier or an isolation amplifier. The voltage at the input end of the voltage follower 31 is the same as the voltage at the output end. Exemplarily, when the voltage value at the output end of the voltage follower 31 is e(t), the voltage value at the input end of the voltage follower 31 is also e(t).

[0076] The voltage follower 31 has the characteristics of high impedance at the input end and low impedance at the output end, so it has the function of in-phase buffering voltage and maintaining signal amplitude. The output end of the voltage follower 31 is coupled to the output end of the voltage generating unit, so that the output end voltage of the voltage follower 31 can be the test voltage output by the voltage generating unit. Since the voltage at the input end of the voltage follower 31 is the same as the voltage at the output end, the input end voltage of the voltage follower 31 is also the test voltage. The input end of the voltage follower 31 has high impedance, forming the high impedance end 21 of the voltage control module.

[0077] In this embodiment, by setting the characteristic that the input terminal voltage of the voltage follower 31 is the same as the output terminal voltage, and coupling the output terminal of the voltage follower 31 with the output terminal of the second voltage generating unit 40, the input terminal voltage of the voltage follower 31 can be made to be the test voltage. By setting the high impedance characteristic of the input terminal of the voltage follower 31, the high impedance terminal 21 formed by the input terminal of the voltage follower 31 can be made to have a high impedance, that is, the second voltage control unit 30 controls the voltage value at the high impedance terminal 21 and the high impedance terminal 21 has no current passing through the function, and then the first voltage control module 20 outputs the test voltage to the first body terminal 71 of the transistor 70 to be tested, so that the actual voltage of the first body terminal 71 is the set test voltage, eliminating the error of the test result caused by the difference between the actual voltage and the set test voltage, and improving the test accuracy.

[0078] In some embodiments, Figure 2 As shown, the voltage follower 31 includes a first operational amplifier 33, a first input terminal of the first operational amplifier 33 constitutes a high-resistance terminal 21, a second input terminal of the first operational amplifier 33 is coupled to an output terminal of the first operational amplifier 33, and an output terminal of the first operational amplifier 33 is coupled to an output terminal of the voltage generating unit.

[0079] Among them, the operational amplifier is a circuit unit with voltage amplification function. The operational amplifier has two input terminals and one output terminal. Its output signal can be the result of mathematical operations such as addition, subtraction, differentiation, integration, etc. of the input signal. The operational amplifier has virtual short and virtual open characteristics. Virtual short means that when analyzing the linear state of the operational amplifier, the two input terminals of the operational amplifier can be regarded as equipotential, that is, the voltages at the two input terminals of the operational amplifier are the same. Virtual open means that the two input terminals of the operational amplifier are equivalent to open circuits, and almost no current flows, that is, the current value at the two input terminals of the operational amplifier is zero.

[0080] The first input terminal and the second input terminal of the first operational amplifier 33 are, for example, a non-inverting input terminal "+" and an inverting input terminal "-", respectively. The first input terminal of the first operational amplifier 33 has a high impedance, and the first input terminal of the first operational amplifier 33 can constitute the high impedance terminal 21 of the voltage control module. The second input terminal of the first operational amplifier 33 is coupled to the output terminal of the first operational amplifier 33, so that the voltage of the output terminal of the first operational amplifier 33 is the same as the voltage of the second input terminal of the first operational amplifier 33. Since the first operational amplifier 33 has the virtual short characteristic as described above, the voltage of the first input terminal of the first operational amplifier 33 is the same as the voltage of the output terminal. The output terminal of the first operational amplifier 33 is coupled to the output terminal of the voltage generating unit, so that the voltage at the output terminal of the first operational amplifier 33 is the test voltage output by the voltage generating unit. Since the voltage of the first input terminal of the first operational amplifier 33 is the same as the voltage of the output terminal, the voltage of the first input terminal of the first operational amplifier 33 is also the test voltage, that is, the voltage at the high impedance terminal 21 is the test voltage.

[0081] In this embodiment, the output terminal of the first operational amplifier 33 is set to have a high impedance characteristic, so that the first input terminal of the first operational amplifier 33 can constitute the high impedance terminal 21 of the voltage control module. By coupling the output terminal of the first operational amplifier 33 with the second input terminal of the first operational amplifier 33 and the output terminal of the voltage generating unit, and the characteristic that the voltages of the first input terminal and the second input terminal of the first operational amplifier 33 are the same, the voltage at the first input terminal of the first operational amplifier 33 is the same as the test voltage output by the voltage generating unit, and the test voltage is output to the first body terminal 71 of the transistor 70 to be tested through the high impedance terminal 21, so that the actual voltage value at the first body terminal 71 of the transistor 70 to be tested is the set test voltage value, eliminating the error of the test result caused by the difference between the actual voltage and the set test voltage, and improving the test accuracy.

[0082] In some embodiments, Figure 2 As shown, a blocking inductor 32 is further provided between the input end of the voltage follower 31 and the first test pad 61 , and the blocking inductor 32 is used to prevent the alternating current from flowing to the first test pad 61 .

[0083] The voltage control unit 30 is provided with a choking inductor 32 in addition to the voltage follower 31 . The choking inductor 32 is arranged between the input end of the voltage follower 31 and the first test pad 61 . The choking inductor 32 can prevent the alternating current from flowing to the first test pad 61 .

[0084] It should be noted that the impedance of the input end of the voltage follower 31 as above is relatively high, and the high-resistance end 21 it constitutes is equivalent to a short circuit and no current passes through. During the test process, if, for example, the resistance of the high-resistance end 21 decreases or the voltage control fails, there is still a possibility that a weak AC current flows through the high-resistance end 21. When the current exists and flows to the first body end 71, it will cause a change in the ohmic potential drop and make the actual voltage at the first body end 71 of the transistor 70 to be tested smaller than the test voltage output by the voltage control module, which will still interfere with the test results and lead to problems such as large test errors and low test accuracy.

[0085] In this embodiment, a blocking inductor 32 is provided between the output end of the voltage follower 31 and the first test pad 61, so that even if there is a weak current at the high resistance end 21 under special circumstances, the blocking inductor 32 can prevent the current from flowing to the first test pad 61, further ensuring that no current flows to the first body end 71 of the transistor to be tested 70, and avoiding the current flowing to the first body end 71 due to the change of the ohmic potential drop caused by the first equivalent resistor 82, so that the actual voltage at the first body end 71 is less than the test voltage output by the voltage control module, thereby eliminating interference with the test results and improving the test accuracy.

[0086] In some embodiments, Figure 2 As shown, the second voltage generating unit 40 includes a second signal generator 41, one end of the second signal generator 41 is coupled to the common ground end, and the other end of the second signal generator 41 constitutes the output end of the second voltage generating unit 40, and the signal generator is used to output a test voltage with a preset waveform.

[0087] The second signal generator 41 can generate different types of waveform signals to output a test voltage with a preset waveform, and the preset waveform can be, for example, a sine wave, a triangle wave, a square wave, etc. During the test process, the frequency and amplitude of the preset waveform can be gradually increased, so that the test circuit 10 performs an electrical test on the transistor 70 to be tested according to the preset waveform of the test voltage and the corresponding current change in the transistor 70 to be tested.

[0088] One end of the second signal generator 41 is, for example, a ground end, and the ground end of the second signal generator 41 is coupled to the common ground end to provide an accurate reference signal. The other end of the second signal generator 41 is, for example, an output end, and the output end of the second signal generator 41 constitutes the output end of the second voltage generating unit 40, that is, the output end of the second signal generator 41 is also coupled to the output end of the voltage follower 31 or the first operational amplifier 33 as above, for outputting a test voltage to the voltage control unit 30.

[0089] In this embodiment, the second signal generator 41 is configured to output a test voltage having a preset waveform, so that the test circuit 10 can perform an electrical test on the transistor 70 to be tested according to the preset waveform of the test voltage and the corresponding current change in the transistor 70 to be tested. One end of the signal generator is coupled to the common ground terminal, and a reference signal can be provided through the common ground terminal. The other end of the signal generator constitutes the output end of the second voltage generating unit 40, and the test voltage can be output to the voltage control unit 30 through the other end of the second signal generator 41, and then the test voltage is finally output to the first body terminal 71 of the transistor 70 to be tested, so that the actual voltage of the first body terminal 71 is the set test voltage, thereby eliminating the error of the test result caused by the difference between the actual voltage and the set test voltage, and improving the test accuracy.

[0090] In some embodiments, Figure 6 As shown, the preset waveform includes a sinusoidal waveform with a constant slope and a constant offset.

[0091] The preset waveform of the constant-slope sinusoidal waveform with a constant offset can be regarded as: Figures 7 to 9 The equal slope waveform, sinusoidal waveform and constant offset waveform shown are combined, and the preset waveform has the characteristics of the same slope, sinusoidal change and constant offset of the three, that is, the signal generator outputs a test voltage e(t) with a preset waveform and changes with time t.

[0092] In this embodiment, setting the preset waveform to a sinusoidal waveform with a constant slope and a constant offset can eliminate the interference of other components in the test circuit 10 on the preset waveform of the test voltage, and can enhance the response of the transistor 70 under test to the test voltage, thereby improving the test accuracy and test efficiency.

[0093] In some embodiments, Figure 2 As shown, the current control module 50 includes a second operational amplifier 52 , a first input terminal of the second operational amplifier 52 is coupled to the output terminal of the voltage generating unit, and an output terminal of the second operational amplifier 52 constitutes a current control terminal 51 .

[0094] The current control module 50 includes a second operational amplifier 52. The operational amplifier is a circuit unit with a voltage amplification function. The operational amplifier has two input terminals and one output terminal. Its output signal can be the result of mathematical operations such as addition, subtraction, differentiation, and integration of the input signal. The operational amplifier has virtual short and virtual open characteristics. The virtual short means that when analyzing the linear state of the operational amplifier, the two input terminals of the operational amplifier can be regarded as equipotential, that is, the voltages at the two input terminals of the operational amplifier are the same. The virtual open means that the two input terminals of the operational amplifier are equivalent to an open circuit, and almost no current flows, that is, the current value at the two input terminals of the operational amplifier is zero.

[0095] The second input terminal and the first input terminal of the second operational amplifier 52 are, for example, the in-phase input terminal "+" and the inverting input terminal "-", respectively. The first input terminal of the second operational amplifier 52 is coupled to the output terminal of the voltage generating unit, so that the voltage of the first input terminal of the second operational amplifier 52 is the test voltage output by the voltage generating unit. Since the second operational amplifier 52 has the virtual short characteristic as described above, the voltage of the second input terminal of the second operational amplifier 52 is the same as the voltage of the first input terminal. The second input terminal of the second operational amplifier 52 can be set to be suspended, for example, and the second input terminal of the second operational amplifier 52 can also be set to be connected to the common ground terminal after passing through a resistor. There is current at the output terminal of the second operational amplifier 52, and the output terminal of the second operational amplifier 52 constitutes the current control terminal 51, and the current is controlled by the second operational amplifier 52, and then the output terminal of the second operational amplifier 52 is connected to the second test pad 62 corresponding to the second body terminal 72, the source terminal 73, and the drain terminal 74 of the transistor to be tested, that is, the current control module 50 controls the current flowing through the transistor to be tested 70 through the second operational amplifier 52.

[0096] In this embodiment, by providing a second operational amplifier 52, and coupling the first input terminal of the second operational amplifier 52 to the output terminal of the voltage generating unit, the voltage at the first input terminal and the voltage at the second input terminal of the second operational amplifier 52 are both test voltages. The output terminal of the second operational amplifier 52 constitutes a current control terminal 51, and the current flowing through the transistor to be tested 70 can be controlled by the second operational amplifier 52, so that the second equivalent resistance 83 of the transistor to be tested 70 and the current in the capacitor structure 81 as a response signal are the same, so that the current flowing through the transistor to be tested 70 can be obtained by detecting the current control terminal 51.

[0097] In an exemplary embodiment, a test device is provided, which includes the test circuit 10 as described above, and also includes a first test probe and a second test probe corresponding to each transistor 70 to be tested, the first test probe is used to contact the first test pad 61, and the second test probe is used to contact the second test pad 62 of the corresponding transistor 70 to be tested.

[0098] Among them, the test equipment includes the above-mentioned test circuit 10 and a first test probe and a second test probe, the first test probe is connected to the high resistance end 21 in the test circuit 10, and the first test probe is used to contact the first test pad 61, that is, the high resistance end 21 in the test circuit 10 and the first test pad 61 corresponding to the first body end 71 of the transistor 70 to be tested are connected by the first test probe of the test equipment, so that the first voltage control module 20 outputs the test voltage to the first body end 71.

[0099] The second test probe is connected to the voltage supply terminal 110 of the second voltage control module 100 in the test circuit 10, and the second test probe is used to contact the second test pad 62, that is, the voltage supply terminal 110 in the test circuit 10 and the second test pad 62 corresponding to the gate terminal 75 of the transistor 70 to be tested are connected through the second test probe of the test equipment, so that the second voltage control module outputs voltage to the second body terminal 72.

[0100] In this embodiment, by setting a first voltage control module 20 including a high resistance terminal 21, it is ensured that the voltage input to the first body terminal 71 of the transistor to be tested 70 is always the test voltage, and the ohmic potential drop caused by other resistance values ​​of the transistor to be tested 70 other than the impedance is prevented from interfering with the set test voltage. Since the voltage value of the test voltage connected to the first body terminal 71 and the voltage value of the output voltage of the relatively independent voltage supply terminal are both constant voltages, the voltage difference applied to the two ends of the transistor to be tested 70 is always in a stable state, and the voltage of the gate terminal of other transistors to be tested is prevented from being affected when a certain transistor to be tested 70 breaks down. Therefore, multiple transistors to be tested can be tested simultaneously, effectively shortening the evaluation cycle of the voltage acceleration factor of each transistor to be tested 70, so as to improve the process efficiency of the semiconductor structure.

[0101] It should be noted that the reference Figure 2 As shown, when the semiconductor test structure is electrically tested by the test equipment, other resistances in the test circuit, such as wire resistance and contact resistance, also form a third equivalent resistance 84. However, the test circuit is different from the test circuit 10' of the prior art. Due to the setting of the voltage control module and the current control module in the test circuit, the third equivalent resistance 84 will not cause the change of the ohmic potential drop and cause the actual voltage of the first body terminal to deviate from the set test voltage, thereby affecting the test result.

[0102] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the present disclosure. This application is intended to cover any variations, uses or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the claims.

[0103] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A test circuit for performing electrical testing on a semiconductor test structure, wherein the semiconductor test structure comprises a plurality of transistors to be tested, characterized in that: The test circuit comprises: A first voltage control module, the first voltage control module comprising a high resistance end, the high resistance end being used to be connected to first test pads corresponding to the first body end of each of the transistors to be tested, so as to output a test voltage to the first body end of each of the transistors to be tested; A second voltage control module, the second voltage control module includes a plurality of independent voltage supply terminals corresponding one by one to the plurality of transistors to be tested, the voltage supply terminals are used to be connected to second test pads corresponding to the gate terminals of the corresponding transistors to be tested, so as to form a detection current on the corresponding transistors to be tested.

2. The test circuit according to claim 1, characterized in that: Among the plurality of voltage supply terminals, one of the voltage supply terminals is connected to a common ground terminal.

3. The test circuit according to claim 1, characterized in that: The second voltage control module also includes an operation unit connected to at least one of the voltage supply terminals, a first input terminal of the operation unit is coupled to the high resistance terminal, a second input terminal of the operation unit is connected to a first voltage generating unit, and an output terminal of the operation unit constitutes one of the voltage supply terminals.

4. The test circuit according to claim 3, characterized in that: The operation unit includes an adder, a subtractor, a multiplier or a divider.

5. The test circuit according to claim 3, characterized in that: The second voltage control module includes a computing unit connected to different voltage supply terminals respectively; Different computing units are connected to different first voltage generating units, or, Different operation units are connected to the same first voltage generating unit, and the first voltage generating unit is used to provide different voltage signals to different operation units.

6. The test circuit according to any one of claims 1 to 5, characterized in that: The first voltage control module includes a voltage control unit and a second voltage generating unit, one end of the voltage control unit constitutes the high impedance end, and the other end of the voltage control unit is coupled to the output end of the second voltage generating unit.

7. The test circuit according to claim 6, characterized in that: The voltage control unit includes a voltage follower, an output end of the voltage follower is coupled to an output end of the second voltage generating unit, and an input end of the voltage follower constitutes the high-resistance end.

8. The test circuit according to claim 7, characterized in that: The voltage follower includes a first operational amplifier, a first input terminal of the first operational amplifier constitutes the high impedance terminal, a second input terminal of the first operational amplifier is coupled to an output terminal of the first operational amplifier, and an output terminal of the first operational amplifier is coupled to an output terminal of the second voltage generating unit.

9. The test circuit according to claim 6, characterized in that: The test circuit also includes a second operational amplifier, a first input terminal of the second operational amplifier is coupled to the output terminal of the second voltage generating unit, and the output terminal of the second operational amplifier is used to connect to the third test pads corresponding to the second body terminal, source terminal, and drain terminal of each of the transistors to be tested.

10. A testing device, characterized in that: The testing device includes the testing circuit as described in any one of claims 1 to 9, and the testing device also includes a first testing probe and a second testing probe corresponding to each of the transistors to be tested, the first testing probe is used to contact the first testing pad, and the second testing probe is used to contact the second testing pad of the corresponding transistor to be tested.

Images