Device reliability evaluation method, device reliability evaluation apparatus, and computer readable storage medium
By setting a first parameter characterizing the ratio of gate voltage to drain voltage, multiple lifetime tests are conducted to obtain the time degradation factor and drain voltage acceleration factor, and a device reliability degradation model is established. This solves the problem of inaccurate evaluation caused by gate voltage variation and improves the evaluation accuracy.
Patent Information
- Application Number
- CN202411162179.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-22
- Publication Date
- 2026-03-03
AI Technical Summary
The inaccuracy of device reliability assessment in the prior art is mainly due to the inaccuracy of the device reliability degradation model caused by the change of gate voltage with drain voltage.
By setting a first parameter to characterize the ratio of gate voltage to drain voltage, multiple lifetime tests are conducted to obtain the time degradation factor and the acceleration factor of drain voltage, thereby establishing a device reliability degradation model and avoiding the influence of gate voltage changes.
This improves the accuracy of device reliability degradation models and enhances the accuracy of device reliability assessment methods.
Smart Images
Figure CN121598566A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductors, and in particular to a method for evaluating device reliability, a device for evaluating device reliability, and a computer-readable storage medium. Background Technology
[0002] Integrated circuit reliability refers to the ability of a chip to perform its intended function under specified conditions and within a specified time. Reliability cannot be directly measured; it is a time-dependent function. The failure rate function, also known as the instantaneous failure rate, refers to the probability that a product that has not failed at a certain point in its operation will fail within a unit of time after that point. Wear-off failure refers to the performance degradation caused by a chip after long-term operation and degradation, gradually approaching the end of its lifespan. Wear-off failure includes hot carrier injection (HCI), negative bias temperature instability (NBTI), electromigration (EM), and time-dependent dielectric breakdown (TDDB) degradation.
[0003] To expose failed chips as early as possible, accelerated life testing is typically used to predict the time it takes for a chip to fail under specified conditions. This prediction process is the process of establishing a device reliability degradation model. Therefore, it is necessary to establish a model that can accurately describe device reliability degradation, and to evaluate the reliability of the device using this model.
[0004] However, there are still many problems in the current assessment of device reliability. Summary of the Invention
[0005] The problem addressed by this invention is how to establish a model that accurately describes the reliability degradation of a device in order to accurately assess the reliability of the device under test.
[0006] To address the aforementioned problems, this invention provides a device reliability assessment method, comprising: providing a device under test (DUT); performing multiple first lifetime tests on the DUT for device performance parameters based on preset first parameters, obtaining a time degradation factor for the device performance parameters of the DUT in each first lifetime test, wherein the first parameter is suitable for characterizing the ratio of gate voltage to drain voltage; obtaining an acceleration factor for the drain voltage of the DUT based on the multiple first lifetime tests for device performance parameters; performing multiple second lifetime tests on the DUT for device performance parameters to obtain an acceleration factor for the first parameters; and obtaining a device reliability degradation model of the DUT based on the acceleration factor of the first parameters, the time degradation factor of the device performance parameters, and the acceleration factor of the drain voltage.
[0007] Optionally, in the step of performing multiple first lifetime tests on the device under test (DUT) based on preset first parameters, the first lifetime test includes: setting a first drain voltage; obtaining a first gate voltage based on the first drain voltage and the preset first parameters; applying the first drain voltage to the drain of the DUT and the first gate voltage to the gate of the DUT to obtain multiple first performance measurements of the DUT; obtaining the relationship between the device performance parameters of the DUT and time under the first drain voltage based on the multiple first performance measurements of the DUT; and obtaining the time degradation factor of the device performance parameters of the DUT based on the relationship between the device performance parameters and time.
[0008] Optionally, the step of performing multiple second lifetime tests on the device performance parameters of the device under test to obtain the acceleration factor of the first parameter includes: performing multiple second lifetime tests on the device performance parameters of the device under test, obtaining the relationship between the device performance parameters of the device under test and time in each second lifetime test; and obtaining the acceleration factor of the first parameter based on the relationship between the device performance parameters of multiple devices under test and time.
[0009] Optionally, in the step of performing multiple second lifetime tests on the device under test (DUT) for device performance parameters, the second lifetime test includes: setting a second drain voltage and a second gate voltage; applying the second drain voltage to the drain of the DUT and the second gate voltage to the gate of the DUT to obtain multiple second performance measurements of the DUT; and obtaining the relationship between the device performance parameters of the DUT and time under the second drain voltage and the second gate voltage based on the multiple second performance measurements of the DUT.
[0010] Optionally, it also includes: setting a first parameter according to the device under test.
[0011] Optionally, the step of setting the first parameter according to the device under test includes: obtaining the model type according to the device under test; and setting the first parameter according to the model type.
[0012] Optionally, the model type includes one of the 1 / Vd model and the Isub / Id model.
[0013] Optionally, the device performance parameters include: the drain current of the device under test when it is operating in the saturation region, the drain current of the device under test when it is operating in the linear region, the threshold voltage of the device under test, and the transconductance.
[0014] Optionally, the step of obtaining the device reliability degradation model of the device under test includes: obtaining a second parameter based on the acceleration factor of the first parameter, the time degradation factor of the device performance parameter, and the acceleration factor of the drain voltage; and obtaining the device reliability degradation model of the device under test based on the second parameter.
[0015] Optionally, in the step of obtaining the second parameter, the second parameter is expressed as: A = δP / exp(-Β / Vd)*(Vg / Vd) -N *t n Where: P represents the device performance parameter, δP represents the degradation rate of the device performance parameter P, A represents the second parameter, B represents the acceleration factor of the drain voltage, Vd represents the drain voltage, Vg represents the gate voltage, N represents the acceleration factor of the first parameter, t represents time, and n represents the time degradation factor.
[0016] Optionally, it also includes: evaluating the device under test according to the device reliability degradation model of the device under test.
[0017] Accordingly, the present invention also provides a device for evaluating device reliability, comprising:
[0018] The first test module is adapted to perform multiple first lifetime tests on the device performance parameters of the device under test according to a preset first parameter. Each first lifetime test obtains a time degradation factor of the device performance parameters of the device under test, wherein the first parameter is suitable for characterizing the ratio of gate voltage to drain voltage.
[0019] The first acquisition module is adapted to obtain the acceleration factor of the drain voltage of the device under test based on the first lifetime test of the multiple device performance parameters.
[0020] The second test module is adapted to perform multiple second lifetime tests on the device under test to obtain the acceleration factor of the first parameter.
[0021] The second acquisition module is adapted to obtain the device reliability degradation model of the device under test based on the acceleration factor of the first parameter, the time degradation factor of the device performance parameter, and the acceleration factor of the drain voltage.
[0022] Accordingly, the present invention also provides a computer-readable storage medium having a computer program stored thereon, characterized in that the computer program is executed by a processor to implement the steps of any of the above-described methods for evaluating the reliability of the device.
[0023] Compared with the prior art, the technical solution of the present invention has the following advantages:
[0024] In the device reliability evaluation method of the present invention, the device reliability degradation model includes a first parameter and an acceleration factor of the first parameter, but does not include the gate voltage and the acceleration factor of the gate voltage. The first parameter represents the ratio of the gate voltage to the drain voltage. The first parameter is a constant value, which avoids the problem of inaccuracy of the device reliability degradation model caused by the change of the gate voltage with the drain voltage, improves the accuracy of the device reliability degradation model, and improves the accuracy of the device reliability evaluation method. Attached Figure Description
[0025] Figure 1 This is a schematic diagram illustrating the application of a device reliability degradation model in one embodiment;
[0026] Figure 2 This is a flowchart of each step in the device reliability evaluation method according to an embodiment of the present invention;
[0027] Figure 3 This is a flowchart of each step of the first lifetime test according to an embodiment of the present invention;
[0028] Figure 4 This is a data graph of the time degradation factor obtained from the first lifetime test in an embodiment of the present invention;
[0029] Figure 5 This is a data graph of the acceleration factor of the drain voltage obtained in the first lifetime test of this invention embodiment;
[0030] Figure 6 This is a flowchart of the steps for obtaining the acceleration factor of the first parameter according to an embodiment of the present invention;
[0031] Figure 7 This is a flowchart of each step of the second lifetime test according to an embodiment of the present invention;
[0032] Figure 8 Figure 1 shows the data of the acceleration factor of the first parameter obtained in the second lifetime test of this embodiment of the invention.
[0033] Figure 9 Figure 2 shows the data of the acceleration factor of the first parameter obtained from the second lifetime test of this embodiment of the invention.
[0034] Figure 10 This is a flowchart of each step in obtaining a device reliability degradation model according to an embodiment of the present invention;
[0035] Figure 11 This is a device for evaluating the reliability of devices according to an embodiment of the present invention. Detailed Implementation
[0036] As is known from the background art, the reliability assessment of existing devices suffers from inaccurate assessments. The reasons for this inaccuracy are analyzed below with reference to an embodiment.
[0037] In one embodiment, the device reliability degradation model is δP = A * exp(-B / Vd) * Vg -N *t n ,
[0038] Wherein: P represents the device performance parameter, δP represents the degradation rate of the device performance parameter P, A represents the parameter factor, B represents the acceleration factor of the drain voltage, Vd represents the drain voltage, Vg represents the gate voltage, N represents the acceleration factor of the gate voltage, t represents time, and n represents the time degradation factor.
[0039] The model type includes one of the 1 / Vd model and the Isub / Id model. Specifically, in this embodiment, the model type is the 1 / Vd model.
[0040] In the device reliability degradation model δP=A*exp(-Β / Vd)*Vg -N *t n In the model, the gate voltage Vg changes with the drain voltage Vd. In the Isub / Id type model, when the drain voltage Vd is constant, the gate voltage Vg is taken at the position corresponding to the peak value of the substrate current; in the 1 / Vd type model, the gate voltage Vg is the same as the drain voltage Vd.
[0041] Please refer to Figure 1 , Figure 1 The x-coordinate is 1 / Vd. Figure 1 The vertical axis is Vg, where Vd represents the drain voltage and Vg represents the gate voltage.
[0042] Given δP=A*exp(-Β / Vd)*Vg -N *t nIn this context, the values of B, N, and n are given. When the device performance parameters at point C are known, the calculation path for the device performance parameters at point F based on the device reliability degradation model is as follows: using point C as the base point, keeping the gate voltage constant, calculate the device performance parameters at point D1 using the acceleration factor of the drain voltage; using point D1 as the base point, keeping the drain voltage constant, calculate the device performance parameters at point F using the acceleration factor of the gate voltage. However, the value of the gate voltage Vg changes with the value of the drain voltage Vd. When the device performance parameters at point C are known, the actual path for obtaining the device performance parameters at point F is as follows: using point C as the base point, obtain the device performance parameters at point D using the acceleration factor of the drain voltage; using point D as the base point, keeping the drain voltage constant, obtain the device performance parameters at point F using the acceleration factor of the gate voltage.
[0043] The gate voltage value VgD1 at point D1 is not equal to the gate voltage value VgD at point D. This causes the device performance parameters calculated by the reliability degradation model of the device to be inconsistent with the actual device performance parameters.
[0044] To address the aforementioned technical problem, the present invention provides a method for evaluating device reliability, comprising: providing a device under test (DUT); performing multiple first lifetime tests on the DUT for device performance parameters according to preset first parameters, obtaining a time degradation factor for the device performance parameters of the DUT in each first lifetime test, wherein the first parameter is suitable for characterizing the ratio of gate voltage to drain voltage; obtaining an acceleration factor for the drain voltage of the DUT based on the multiple first lifetime tests for device performance parameters; performing multiple second lifetime tests on the DUT for device performance parameters to obtain an acceleration factor for the first parameters; and obtaining a device reliability degradation model of the DUT based on the acceleration factor of the first parameters, the time degradation factor of the device performance parameters, and the acceleration factor of the drain voltage.
[0045] In the device reliability assessment method of this invention, a time degradation factor and a drain voltage acceleration factor are obtained based on a preset first parameter. Then, a device reliability degradation model of the device under test is obtained based on the acceleration factor of the first parameter, the time degradation factor, and the drain voltage acceleration factor. The device reliability degradation model includes the first parameter and its acceleration factor, but excludes the gate voltage and its acceleration factor. The first parameter represents the ratio of the gate voltage to the drain voltage and is a constant. This avoids the problem of inaccurate device reliability degradation models caused by changes in gate voltage with drain voltage, thus improving the accuracy of the device reliability degradation model and the overall accuracy of the device reliability assessment method.
[0046] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
[0047] Please refer to Figure 2 The steps of the device reliability evaluation method according to embodiments of the present invention include:
[0048] Step S10: Provide the device under test;
[0049] Step S11: According to the preset first parameter, perform multiple first lifetime tests on the device under test for device performance parameters. Each first lifetime test obtains a time degradation factor of the device performance parameters of the device under test, wherein the first parameter is suitable for characterizing the ratio of gate voltage to drain voltage.
[0050] Step S12: Based on the first lifetime test of the multiple device performance parameters, obtain the acceleration factor of the drain voltage of the device under test.
[0051] Step S13: Perform multiple second lifetime tests on the device performance parameters of the device under test to obtain the acceleration factor of the first parameter;
[0052] Step S14: Based on the acceleration factor of the first parameter, the time degradation factor of the device performance parameter, and the acceleration factor of the drain voltage, obtain the device reliability degradation model of the device under test.
[0053] The following section will provide a detailed explanation of each step in the method for evaluating device reliability.
[0054] In step S11, please refer to Figure 3 The steps of the first life test include:
[0055] Step S110: Set the first drain voltage;
[0056] Step S111: Based on the first drain voltage and combined with the preset first parameters, obtain the first gate voltage;
[0057] Step S112: Apply a first drain voltage to the drain of the device under test and apply a first gate voltage to the gate of the device under test to obtain multiple first performance measurement values of the device under test.
[0058] Step S113: Based on multiple first performance measurement values of the device under test, obtain the relationship between the device performance parameters of the device under test and time under the first drain voltage;
[0059] Step S114: Based on the relationship between the device performance parameters of the device under test and time, obtain the time degradation factor of the device performance parameters of the device under test.
[0060] The steps of the device reliability evaluation method include: setting a first parameter according to the device under test.
[0061] The steps for setting the first parameter based on the device under test include:
[0062] Based on the device under test, the model type is obtained;
[0063] Set the first parameter according to the model type.
[0064] In some embodiments of the present invention, the first parameter is a fixed constant, and the value range of the first parameter is 0 to 1; in other embodiments, the first parameter may also be a non-fixed value.
[0065] Based on the application scenario of the device under test, a model type is obtained. The model type includes one of a 1 / Vd model and an Isub / Id model. In the 1 / Vd model, the value of the first parameter is 1; in the Isub / Id model, the value of the first parameter is 0.5. Specifically, in some embodiments of the present invention, the device reliability degradation model is a 1 / Vd model, and in some embodiments of the present invention, the value of the first parameter is 1.
[0066] In step S110, a first drain voltage is set. For example, the first drain voltage is set to Vd1-1.
[0067] In step S111, based on the first drain voltage Vd1-1 and the preset value of the first parameter 1, a first gate voltage Vg1-1 corresponding to the first drain voltage is obtained. Vg1-1 = Vd1-1.
[0068] In step S112, multiple first performance measurements of the device under test are obtained. These first performance measurements include:
[0069] A first drain voltage is applied to the drain of the device under test (DUT), and a first gate voltage is applied to the gate of the DUT. The measured value of the drain current when the DUT is operating in the saturation region is obtained.
[0070] A first drain voltage is applied to the drain of the device under test (DUT), and a first gate voltage is applied to the gate of the DUT. The measured value of the drain current when the DUT is operating in the linear region is obtained.
[0071] A first drain voltage is applied to the drain of the device under test (DUT), and the measured value of the threshold voltage of the DUT under the first gate voltage is applied to the gate of the DUT.
[0072] A first drain voltage is applied to the drain of the device under test, and a first gate voltage is applied to the gate of the device under test to measure the transconductance of the device under test.
[0073] Specifically, in some embodiments of the present invention, the first performance measurement value is the measurement value of the threshold voltage of the device under test (DUT) when a first drain voltage is applied to the drain of the DUT and a first gate voltage is applied to the gate of the DUT. For example, when a first drain voltage Vd1-1 is applied to the drain of the DUT and a first gate voltage Vg1-1 is applied to the gate of the DUT, the first performance measurement values Vtlin1-1-1, Vtlin1-1-2, ... Vtlin1-1-n of the DUT are obtained.
[0074] In step S113, please refer to Figure 4 , Figure 4 This is a data graph of the time degradation factor of the device performance parameters obtained from multiple first-life tests of device performance parameters. Figure 4 The horizontal axis represents time, and the unit of the horizontal axis is seconds. Figure 4 The vertical axis represents the threshold voltage, and the unit of the vertical axis is volts.
[0075] Figure 4 The following are shown respectively:
[0076] When the first drain voltage Vd1-1 is 1.2V and the first gate voltage Vg1-1 is 1.2V, the relationship curve between the first performance measurement values Vtlin1-1-1, Vtlin1-1-2, ... Vtlin1-1-n of the device under test and time t is shown in Figure 1.
[0077] When the first drain voltage Vd1-2 is 1.3V and the first gate voltage Vg1-2 is 1.3V, the curve 2 shows the relationship between the first performance measurement values Vtlin1-2-1, Vtlin1-2-2, ... Vtlin1-2-n of the device under test and time t.
[0078] When the first drain voltage Vd1-3 is 1.4V and the first gate voltage Vg1-3 is 1.4V, the relationship curve 3 between the first performance measurement values Vtlin1-3-1, Vtlin1-3-2, ... Vtlin1-3-n of the device under test and time t is shown.
[0079] In step S114, please continue to refer to Figure 4 Based on the relationship between the threshold voltage Vtlin of the device under test (DUT) and time t, the time degradation factor n of the DUT's performance parameters is obtained. Example:
[0080] Based on the slope of curve 1, the time degradation factor n1 of the device under test is obtained when the first drain voltage Vd1-1 is 1.2V and the first gate voltage Vg1-1 is 1.2V.
[0081] Based on the slope of curve 2, the time degradation factor n2 of the device under test is obtained when the first drain voltage Vd1-2 is 1.3V and the first gate voltage Vg1-2 is 1.3V.
[0082] Based on the slope of curve 3, the time degradation factor n3 of the device under test is obtained when the first drain voltage Vd1-3 is 1.4V and the first gate voltage Vg1-3 is 1.4V.
[0083] In step S12, please refer to the reference. Figure 4 and Figure 5 , Figure 5 This is a data graph of the acceleration factor of the drain voltage of the device under test obtained from the first lifetime test of the multiple device performance parameters. Figure 5 The x-coordinate is 1 / Vd. Figure 5 The ordinate is Figure 4 The vertical axis represents the time corresponding to the threshold voltage.
[0084] Figure 4 The threshold voltage standard line is 4. Figure 5 The ordinates of the midpoints X1, X2, and X3 correspond to respectively Figure 4 The x-coordinates of the intersection points of the three curves and the standard line 4 are:
[0085] The vertical axis value of X1 is the horizontal axis value of the intersection point of curve 1 and the threshold voltage standard line 4 when Vd1-1 is 1.2V.
[0086] The vertical axis value of X2 is the horizontal axis value of the intersection point of curve 2 and the threshold voltage standard line 4 when Vd1-2 is 1.3V.
[0087] The vertical axis of X3 is the value of the horizontal axis of the intersection point of curve 3 and threshold voltage standard line 4 when Vd1-3 is 1.4V.
[0088] The x-coordinate of X1 is the value of 1 / Vd when Vd is 1.2V, the x-coordinate of X2 is the value of 1 / Vd when Vd is 1.3V, and the x-coordinate of X3 is the value of 1 / Vd when Vd is 1.4V.
[0089] Based on the first lifetime test of the multiple device performance parameters, the acceleration factor B of the drain voltage Vd of the device under test is obtained. That is:
[0090] Based on the first life test, the ordinate and abscissa values of point X1 were obtained;
[0091] Based on the second first life test, the ordinate and abscissa values of point X2 were obtained;
[0092] Based on the third first life test, the ordinate and abscissa values of point X3 were obtained;
[0093] The acceleration factor B of the drain voltage Vd of the device under test can be obtained by calculating the slope of the line connecting points X1, X2, and X3.
[0094] In step S13, please refer to Figure 6 The step of performing multiple second lifetime tests on the device under test to obtain the acceleration factor of the first parameter includes:
[0095] Step S130: Perform multiple second lifetime tests on the device under test to obtain the relationship between the device performance parameters and time for each second lifetime test.
[0096] Step S131: Obtain the acceleration factor of the first parameter based on the relationship between the device performance parameters of the multiple devices under test and time.
[0097] In step S130, please refer to Figure 7 In the step of performing multiple second lifetime tests on the device under test for device performance parameters, the second lifetime test includes:
[0098] Step S1301: Set the second drain voltage and the second gate voltage;
[0099] Step S1302: Apply a second drain voltage to the drain of the device under test and apply a second gate voltage to the gate of the device under test to obtain multiple second performance measurement values of the device under test;
[0100] Step S1303: Based on multiple second performance measurements of the device under test, obtain the relationship between the device performance parameters of the device under test and time under the second drain voltage and the second gate voltage.
[0101] In step S1301, please refer to Figure 8 , Figure 8 Figure 1 shows the acceleration factor data obtained from the second lifetime test for the first parameter. Figure 8 The horizontal axis represents time, and the unit of the horizontal axis is seconds. Figure 8 The vertical axis represents the threshold voltage, and the unit of the vertical axis is volts.
[0102] In step S1301, for example, the second drain voltage Vd2-1 is set to 1.3V and the second gate voltage Vg2-1 is set to 0.6V;
[0103] Set the second drain voltage Vd2-2 to 1.3V and the second gate voltage Vg2-2 to 0.99V;
[0104] Set the second drain voltage Vd2-3 to 1.3V and the second gate voltage Vg2-3 to 1.1V.
[0105] In step S1302, multiple second performance measurements of the device under test are obtained. These second performance measurements include:
[0106] A second drain voltage is applied to the drain of the device under test (DUT), and a second gate voltage is applied to the gate of the DUT. The measured value of the drain current when the DUT is operating in the saturation region is obtained.
[0107] A second drain voltage is applied to the drain of the device under test (DUT), and a second gate voltage is applied to the gate of the DUT. The measured value of the drain current when the DUT is operating in the linear region is obtained.
[0108] A second drain voltage is applied to the drain of the device under test (DUT), and the measured value of the threshold voltage of the DUT under the second gate voltage is applied to the gate of the DUT.
[0109] A second drain voltage is applied to the drain of the device under test, and a second gate voltage is applied to the gate of the device under test to measure the transconductance of the device under test.
[0110] Specifically, in some embodiments of the present invention, the second performance measurement value is the measurement value of the threshold voltage of the device under test when a second drain voltage is applied to the drain of the device under test and a second gate voltage is applied to the gate of the device under test.
[0111] Example:
[0112] When a second drain voltage Vd2-1 is applied to the drain of the device under test and a second gate voltage Vg2-1 is applied to the gate of the device under test, the second performance measurement values Vtlin2-1-1, Vtlin2-1-2, ... Vtlin2-1-n of the device under test are obtained.
[0113] When a second drain voltage Vd2-2 is applied to the drain of the device under test and a second gate voltage Vg2-2 is applied to the gate of the device under test, the second performance measurement values Vtlin2-2-1, Vtlin2-2-2, ... Vtlin2-2-n of the device under test are obtained.
[0114] When a second drain voltage Vd2-3 is applied to the drain of the device under test and a second gate voltage Vg2-3 is applied to the gate of the device under test, the second performance measurement values Vtlin2-3-1, Vtlin2-3-2, ... Vtlin2-3-n of the device under test are obtained.
[0115] Right now, Figure 8 The following are shown respectively:
[0116] When the second drain voltage Vd2-1 is 1.3V and the second gate voltage Vg2-1 is 0.6V, the relationship curve between the second performance measurement values Vtlin2-1-1, Vtlin2-1-2, ... Vtlin2-1-n of the device under test and time t is shown in Figure 5.
[0117] When the second drain voltage Vd2-2 is 1.3V and the second gate voltage Vg2-2 is 0.99V, the relationship curve between the second performance measurement values Vtlin2-2-1, Vtlin2-2-2, ... Vtlin2-2-n of the device under test and time t is shown in Figure 6.
[0118] When the second drain voltage Vd2-3 is 1.3V and the second gate voltage Vg2-3 is 1.1V, the relationship curve between the second performance measurement values Vtlin2-3-1, Vtlin2-3-2, ... Vtlin2-3-n of the device under test and time t is shown in Figure 7.
[0119] In step S1303, please refer to the reference. Figure 8 and Figure 9 , Figure 9 Figure 2 shows the acceleration factor data obtained from the second life test for the first parameter. Figure 9 The horizontal axis represents the logarithm of the ratio of the second gate voltage to the second drain voltage. Figure 9 The ordinate is Figure 8 The logarithm of the threshold voltage on the vertical axis.
[0120] Figure 9 The ordinate is: Figure 8 The logarithm of the second performance measurement value of the device under test at the same time.
[0121] In some embodiments of the present invention, taking Figure 8 The horizontal axis represents the logarithms of the second performance measurement values Vtlin2-1-x, Vtlin2-2-x, and Vtlin2-3-x of the device under test when the horizontal axis is 1000 seconds. In other embodiments, other time periods may be used.
[0122] Example:
[0123] The vertical coordinate of point X4 is the logarithm of the threshold voltage Vtlin2-1-x of the device under test when Vd2-1 is 1.3V and Vg2-1 is 0.6V, and the horizontal coordinate of point X4 is ln(Vg / Vd)=ln(0.6 / 1.3).
[0124] The vertical coordinate of point X5 is the logarithm of the threshold voltage Vtlin2-2-x of the device under test when Vd2-2 is 1.3V and Vg2-2 is 0.99V, and the horizontal coordinate of point X5 is ln(Vg / Vd)=ln(0.99 / 1.3).
[0125] When Vd2-3 is 1.3V and Vg2-3 is 1.1V, the logarithm of the threshold voltage Vtlin2-3-x of the device under test at 1000 seconds is given by the x-coordinate of point X6, which is ln(Vg / Vd)=ln(1.1 / 1.3).
[0126] Please continue to refer to this. Figure 9 The acceleration factor N of the first parameter of the device under test is obtained based on the slope of the line connecting points X4, X5, and X6. For example, in some embodiments of the present invention, the value of the acceleration factor N of the first parameter is 5.378.
[0127] In step S14, please refer to the reference. Figure 10 The steps for obtaining the device reliability degradation model of the device under test include:
[0128] Step S140: Obtain the second parameter based on the acceleration factor of the first parameter, the time degradation factor of the device performance parameter, and the acceleration factor of the drain voltage;
[0129] Step S141: Obtain the device reliability degradation model of the device under test based on the second parameter.
[0130] In step S140, the second parameter is represented as:
[0131] A = δP / exp(-Β / Vd)*(Vg / Vd) -N *t n Where: P represents the device performance parameter, δP represents the degradation rate of the device performance parameter P, A represents the second parameter, B represents the acceleration factor of the drain voltage, Vd represents the drain voltage, Vg represents the gate voltage, N represents the acceleration factor of the first parameter, t represents time, and n represents the time degradation factor.
[0132] The device performance parameters P include: the drain current Idsat when the device under test is operating in the saturation region, the drain current Idlin when the device under test is operating in the linear region, the threshold voltage Vtlin of the device under test, and the transconductance Gm.
[0133] In step S141, the device reliability degradation model of the device under test is obtained:
[0134] δP=A*exp(-Β / Vd)*(Vg / Vd) -N *t n Where: P represents the device performance parameter, δP represents the degradation rate of the device performance parameter P, A represents the second parameter, B represents the acceleration factor of the drain voltage, Vd represents the drain voltage, Vg represents the gate voltage, N represents the acceleration factor of the first parameter, t represents time, and n represents the time degradation factor.
[0135] Specifically, in some embodiments of the present invention, the device reliability degradation model of the device under test is applicable to devices under test that have experienced degradation due to the Hot Carrier Injection (HCI) effect.
[0136] The device under test (DUT) is evaluated based on its reliability degradation model. Specifically, given the time degradation factor n, the acceleration factor N of the first parameter, the acceleration factor B of the drain voltage, and the second parameter A, the degradation rate of the DUT's performance parameter P can be obtained using any set of parameters (Vd, Vg). The failure time of the DUT is then calculated based on this degradation rate, and the DUT is evaluated using this failure time.
[0137] Accordingly, embodiments of the present invention also provide a device for evaluating device reliability, please refer to... Figure 11 The device includes:
[0138] The first test module 20 is adapted to perform multiple first lifetime tests on the device performance parameters of the device under test according to a preset first parameter. Each first lifetime test obtains a time degradation factor of the device performance parameters of the device under test, wherein the first parameter is suitable for characterizing the ratio of gate voltage to drain voltage.
[0139] The first acquisition module 21 is adapted to obtain the acceleration factor of the drain voltage of the device under test based on the first lifetime test of the multiple device performance parameters.
[0140] The second test module 22 is adapted to perform multiple second lifetime tests on the device under test to obtain the acceleration factor of the first parameter.
[0141] The second acquisition module 23 is adapted to obtain the device reliability degradation model of the device under test based on the acceleration factor of the first parameter, the time degradation factor of the device performance parameter and the acceleration factor of the drain voltage.
[0142] The device reliability evaluation apparatus of the present invention is suitable for performing the steps of the device reliability evaluation method of the present invention. The specific technical solutions of the first test module 20, the first acquisition module 21, the second test module 22, and the second acquisition module 23 can be referred to in the embodiments of the above-described device reliability evaluation method, and will not be repeated here.
[0143] Accordingly, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, characterized in that the computer program is executed by a processor to implement the steps of any of the methods described in the device reliability assessment method.
[0144] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.
Claims
1. A method for evaluating the reliability of a device, characterized in that, include: Provide the device under test; According to a preset first parameter, the device under test is subjected to multiple first lifetime tests of device performance parameters. Each first lifetime test yields a time degradation factor of the device performance parameters of the device under test, wherein the first parameter is suitable for characterizing the ratio of gate voltage to drain voltage. Based on the first lifetime test of the multiple device performance parameters, the acceleration factor of the drain voltage of the device under test is obtained. The device under test is subjected to multiple second lifetime tests on its performance parameters to obtain the acceleration factor of the first parameter. Based on the acceleration factor of the first parameter, the time degradation factor of the device performance parameter, and the acceleration factor of the drain voltage, the device reliability degradation model of the device under test is obtained.
2. The device reliability evaluation method as described in claim 1, characterized in that, In the step of performing multiple first lifetime tests on the device under test based on preset first parameters, the first lifetime test includes: Set the first drain voltage; Based on the first drain voltage and combined with the preset first parameters, the first gate voltage is obtained; A first drain voltage is applied to the drain of the device under test (DUT), and a first gate voltage is applied to the gate of the DUT to obtain multiple first performance measurement values of the DUT. Based on multiple first performance measurements of the device under test, the relationship between the device performance parameters of the device under test and time is obtained under the first drain voltage; Based on the relationship between the device performance parameters of the device under test and time, the time degradation factor of the device performance parameters of the device under test is obtained.
3. The device reliability evaluation method as described in claim 1, characterized in that, The step of performing multiple second lifetime tests on the device under test to obtain the acceleration factor of the first parameter includes: Multiple second lifetime tests are performed on the device under test to obtain the relationship between the device performance parameters and time for each second lifetime test. The acceleration factor of the first parameter is obtained based on the relationship between the device performance parameters of the multiple devices under test and time.
4. The device reliability evaluation method as described in claim 3, characterized in that, In the step of performing multiple second lifetime tests on the device under test (DUT) performance parameters, the second lifetime test includes: Set the second drain voltage and the second gate voltage; A second drain voltage is applied to the drain of the device under test (DUT), and a second gate voltage is applied to the gate of the DUT to obtain multiple second performance measurement values of the DUT. Based on multiple second performance measurements of the device under test, the relationship between the device performance parameters of the device under test and time is obtained under the second drain voltage and the second gate voltage.
5. The device reliability evaluation method as described in claim 1, characterized in that, Also includes: Set the first parameter according to the device under test.
6. The device reliability evaluation method as described in claim 5, characterized in that, The steps for setting the first parameter based on the device under test include: Based on the device under test, the model type is obtained; Set the first parameter according to the model type.
7. The device reliability evaluation method as described in claim 6, wherein the model type includes: One of the 1 / Vd model and the Isub / Id model.
8. The device reliability evaluation method as described in claim 1, characterized in that, The device performance parameters include: the drain current of the device under test when it is operating in the saturation region, the drain current of the device under test when it is operating in the linear region, the threshold voltage of the device under test, and the transconductance.
9. The device reliability evaluation method as described in claim 1, characterized in that, The steps for obtaining the device reliability degradation model of the device under test include: The second parameter is obtained based on the acceleration factor of the first parameter, the time degradation factor of the device performance parameter, and the acceleration factor of the drain voltage. Based on the second parameter, the device reliability degradation model of the device under test is obtained.
10. The device reliability evaluation method as described in claim 9, characterized in that, In the step of obtaining the second parameter, the second parameter is represented as: A=δP / exp(-Β / Vd)*(Vg / Vd) -N *t n , Wherein: P represents the device performance parameter, δP represents the degradation rate of the device performance parameter P, A represents the second parameter, B represents the acceleration factor of the drain voltage, Vd represents the drain voltage, Vg represents the gate voltage, N represents the acceleration factor of the first parameter, t represents time, and n represents the time degradation factor.
11. The device reliability evaluation method as described in claim 1, characterized in that, Also includes: The device under test (DUT) is evaluated based on its device reliability degradation model.
12. A device for evaluating the reliability of a device, characterized in that, include: The first test module is adapted to perform multiple first lifetime tests on the device performance parameters of the device under test according to a preset first parameter. Each first lifetime test obtains a time degradation factor of the device performance parameters of the device under test, wherein the first parameter is suitable for characterizing the ratio of gate voltage to drain voltage. The first acquisition module is adapted to obtain the acceleration factor of the drain voltage of the device under test based on the first lifetime test of the multiple device performance parameters. The second test module is adapted to perform multiple second lifetime tests on the device under test to obtain the acceleration factor of the first parameter. The second acquisition module is adapted to obtain the device reliability degradation model of the device under test based on the acceleration factor of the first parameter, the time degradation factor of the device performance parameter, and the acceleration factor of the drain voltage.
13. A computer-readable storage medium having a computer program stored thereon, characterized in that, The computer program is executed by a processor to implement the steps of the method according to any one of claims 1 to 11.