A method of electromigration testing
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-09-28
- Publication Date
- 2026-08-11
AI Technical Summary
[0004]本申请要解决的技术问题是提供一种电迁移测试的方法，可以在线上及时且快速的评估EM失效风险，提高测试效率，同时还可以解决烧卡或烧衬垫的问题
[0020]通过实际应用条件外推在应力条件下，产品刚好通过待测样本在实际应用场景下满足特定失效率的最低寿命时对应的应力测试时间，通过应力测试时间tstress和待测样本的温度刚到应力温度时的时间tst之和作为电迁移测试时的最短时间tmin，且应力测试时间tstress短于在相同电迁移测试条件下，所述待测样本的电阻达到失效基准时的时间tshift，因此可以缩短测试时间，实现Iso-EM快速test-to-pass的功能。
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Figure CN115877157B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor testing, and more particularly to a method for electromigration testing. Background Technology
[0002] Electromigration (EM) is one of the major failure mechanisms in microelectronic devices. It causes open and short circuits in the metallization, increasing leakage current. As devices evolve towards submicron and deep submicron sizes, the width of the metallization decreases while the current density increases, making them more susceptible to failure due to electromigration. Therefore, with advancements in manufacturing processes, EM evaluation has become increasingly important.
[0003] Traditional methods for evaluating engineering changes mainly include package-level reliability (PLM) EM testing and wafer-level reliability (WLR) isothermal electromigration (Iso-EM) testing. Because WLR iso-EM's testing mechanism has a good and rapid response in defect detection, it is widely used in the evaluation of engineering changes. Summary of the Invention
[0004] The technical problem to be solved by this application is to provide a method for electromigration testing that can assess the risk of EM failure online in a timely and rapid manner, improve testing efficiency, and solve the problem of card burning or gasket burning.
[0005] To address the aforementioned technical problems, this application provides a method for electromigration testing, comprising: obtaining the actual application conditions of the sample under test, the stress temperature during the electromigration test, and the failure distribution variance, wherein the actual application conditions include the current density and temperature of the sample under test in the actual application scenario and the minimum lifetime required to meet a specific failure rate, and the stress temperature is the temperature at which the sample under test reaches isothermal status during the electromigration test; and based on the failure distribution variance, obtaining the stress test time t at the stress temperature that satisfies the actual application conditions. stress The stress test time t stress The time from when the temperature of the sample under test just reaches the stress temperature to the end of the electromigration test is obtained; the electromigration test time is then calculated, and t... stress +t st ≤t<t shift Where t is the electromigration test time, t st t is the time it takes for the temperature of the sample under test to just reach the stress temperature. shiftThe test is defined as the time it takes for the resistance of the sample under test to reach the failure threshold under the same electromigration test conditions; electromigration tests are performed at the stress temperature and the electromigration test time to obtain the electromigration test results.
[0006] In this embodiment of the application, the stress test time t is obtained when the actual application conditions are met at the stress temperature. stress The method includes: obtaining a universal relationship between lifetime and failure time when cumulative failure equals 50% based on the Black equation and electromigration failure distribution density function; and extrapolating the normal lifetime lt when the test sample is a normal sample based on the universal relationship. baseline，yr Failure time t when cumulative failure equals 50% baseline，yr，50 The first relationship between them, and the lifetime of the test sample under practical application conditions. spec，yr Failure time t when cumulative failure equals 50% spec，yr，50 The second relationship between them; processing the first relationship and the second relationship to obtain the t spec，yr，50 With the t baseline，yr，50 lt baseline，yr and lt spec，yr The third relationship between them; processing the universal relationship and the third relationship to obtain the stress test time t. stress .
[0007] In this embodiment of the application, the Black equation is: t 50 =A×J -n ×EXP(E a / kT), where t 50 Let A be the failure time when the cumulative failure rate equals 50%, A be the structure function related to the interconnect material properties, J be the current density under accelerated conditions, n be the acceleration factor of the current density, and E be the failure time. a It is the equivalent diffusion activation energy during the electromigration failure process of interconnect materials, where k is the Boltzmann constant and T is the temperature under acceleration conditions; the electromigration failure distribution density function is: Wherein, PDF(t) is the failure probability density function, t is the failure time; σ is the failure distribution variance, and t50 is the failure time corresponding to a cumulative failure rate of 50%; the universal relation is: lt = AFT × AFJ × t 50 ×EXP[σ×Φ -1 [(CDF)], where lt is the lifetime, AFT is the temperature stress acceleration factor, AFJ is the current stress density acceleration factor, and t 50 The failure time is defined as the time when the cumulative failure rate equals 50%, σ is the variance of the failure distribution of the sample under test, and Φ is the failure time. -1 (CDF) is the inverse function of the cumulative failure distribution function.
[0008] In this embodiment of the application, the first relationship is: lt baseline，yr =AFT×AFJ×t baseline，yr，50 ×EXP[σ×Φ -1 (CDF)]; The second relation is: lt spec，yr =AFT×AFJ×t spec，yr，50 ×EXP[σ×Φ -1 (CDF)
[0009] In this embodiment of the application, the third relationship is: t spec，yr，50 =t baseline，yr，50 Xlt spec，yr / lt baseline，yr .
[0010] In this embodiment of the application, the stress test time t stress For: t stress =lt spec，yr / [AFT×AFJ×EXP(σ*Φ -1 (CDF)
[0011] In this embodiment, the temperature stress acceleration factor AFT is obtained by the following method: AFT = EXP{E a / k[1 / (T op +273)-1 / (T stress +273)]};wherein, E a T is the equivalent diffusion activation energy during the electromigration failure process of interconnect materials, where k is the Boltzmann constant. op T represents the temperature of the actual application scenario of the sample to be tested. stress The stress temperature.
[0012] In this embodiment of the application, the current stress density acceleration factor AFJ is obtained by the following method: AFJ = (J op / J stress ) -n ; among which, J op J represents the current density in the actual application scenario of the sample under test. stress denoted as the current density for the electromigration test, and n is the acceleration factor for the current density.
[0013] In this embodiment of the application, the method for determining the failure distribution variance of the sample to be tested includes: confirming whether there is a failure distribution variance when the sample to be tested is a normal sample; if there is a failure distribution variance when the sample to be tested is a normal sample, then the failure distribution variance when the sample to be tested is a normal sample is used as the failure distribution variance of the sample to be tested.
[0014] In this embodiment of the application, the method for determining the failure distribution variance of the test sample further includes: if the test sample does not have the failure distribution variance when it is a normal sample, then the value of the failure distribution variance of the test sample is not greater than 1.2.
[0015] In this embodiment of the application, the t st The duration should not exceed 10 seconds.
[0016] In this embodiment of the application, the method for obtaining electromigration test results includes: after the electromigration test is completed, obtaining the electrical performance results of the sample under test; if the electrical performance results of the sample under test show normal, then the sample under test passes the test.
[0017] In this embodiment of the application, if the electrical performance of the sample under test is abnormal, the sample under test fails the test.
[0018] In this embodiment of the application, before performing the electromigration test, the method further includes: testing the electrical performance of the sample to be tested to ensure that the electrical performance of the sample to be tested for the electromigration test is normal.
[0019] Compared with the prior art, the technical solution of this application has the following beneficial effects:
[0020] Extrapolating from actual application conditions, under stress conditions, the stress test time corresponding to the minimum lifespan of the product when it just meets a specific failure rate under the test sample in the actual application scenario is obtained. This stress test time t is then used to determine the stress test time. stress The time t when the temperature of the sample just reaches the stress temperature st The sum of these values serves as the shortest time t during electromigration testing. min And the stress test time t stress Shorter than the time t when the resistance of the test sample reaches the failure threshold under the same electromigration test conditions. shift Therefore, testing time can be shortened, enabling Iso-EM to achieve fast test-to-pass functionality.
[0021] Meanwhile, since card and pad burnout generally occurs in the later stages of stress testing, the technical solution of this application can effectively avoid card and pad burnout by shortening the testing time while meeting the minimum lifespan of a specific failure rate, thereby reducing costs. Attached Figure Description
[0022] The following accompanying drawings describe in detail the exemplary embodiments disclosed in this application. The same reference numerals denote similar structures in several views of the drawings. Those skilled in the art will understand that these embodiments are non-limiting and exemplary, and the drawings are for illustrative purposes only and are not intended to limit the scope of this application. Other embodiments may similarly fulfill the inventive intent of this application. It should be understood that the drawings are not drawn to scale. Wherein:
[0023] Figure 1 This is a flowchart illustrating the electromigration testing method according to an embodiment of this application;
[0024] Figure 2 This is a curve showing the temperature change of the sample under test over time during the electromigration test, as described in an embodiment of this application. Detailed Implementation
[0025] The following description provides specific application scenarios and requirements for this application, intended to enable those skilled in the art to make and use the content of this application. Various partial modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of this application. Therefore, this application is not limited to the embodiments shown, but rather to the widest scope consistent with the claims.
[0026] Conventional Iso-EM uses a dead-test method. In Cu processes and low-k insulating layer processes, Iso-EM testing of narrow M1 metals on-line often results in burn-in of chips or pads, increasing testing costs and causing other contamination issues. For Iso-EM testing of wafers with on-line engineering changes or excursions, one current approach is to perform dead-test testing on the normal structure. This method has two drawbacks: firstly, testing time is uncontrollable; a single wafer may have 20 samples of the same structure, and testing time can exceed half a day. If the number of structures or wafers is large, the time increases exponentially. Secondly, there is a risk of burn-in of chips or pads, increasing testing costs or causing contamination. Another current approach is to ignore structures known to burn in this way. This testing method suffers from inadequate evaluation and the presence of unknown risks.
[0027] Therefore, the technical solution of this application extrapolates the stress test time corresponding to the minimum lifetime (OP Lifetime) of the product under stress conditions when the product just meets the specific failure rate in the actual application scenario based on the actual application conditions (OP Spec) of the sample under test, thereby obtaining the electromigration test time. The above method can shorten the electromigration test time to the greatest extent.
[0028] The electromigration testing method of the technical solution of this application will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0029] refer to Figure 1 This application provides a method for electromigration testing, which may include:
[0030] S1: Obtain the actual application conditions of the sample under test, the stress temperature during the electromigration test, and the variance of the failure distribution. The actual application conditions include the current density and temperature of the sample under test in the actual application scenario and the minimum lifetime to meet a specific failure rate. The stress temperature is the temperature at which the sample under test reaches a constant temperature during the electromigration test.
[0031] S2: Based on the failure distribution variance, obtain the stress test time t when the actual application conditions are met at the stress temperature. stress The stress test time t stress The time from when the temperature of the sample under test just reaches the stress temperature to the end of the electromigration test;
[0032] S3: Obtain the electromigration test time, and t stress +t st ≤t<t shift Where t is the electromigration test time, t st t is the time it takes for the temperature of the sample under test to just reach the stress temperature. shift Under the same electromigration test conditions, the time it takes for the resistance of the sample under test to reach the failure reference.
[0033] S4: Perform electromigration testing at the stress temperature and the electromigration test time to obtain electromigration test results.
[0034] In step S1, the actual application conditions of the sample under test refer to the conditions under which the sample is used as a product in actual application scenarios. These actual application conditions may include the current density and temperature of the sample under test in the actual application scenario, as well as the minimum lifetime required to meet a specific failure rate. For example, if the sample under test is a metal interconnect structure on a mobile phone chip, the actual application conditions may be the temperature of the mobile phone during operation, the current density of the mobile phone during operation, and the minimum lifetime required to meet a specific failure rate. In some embodiments, the specific failure rate is the product failure rate required by the customer.
[0035] refer to Figure 2 The electromigration test in this application uses the Iso-EM test method. The Iso-EM test method refers to applying a high-density current to reach a predetermined test temperature, i.e., the stress temperature T. stressThe electromigration test is performed at a constant temperature, maintaining a constant test temperature or stress temperature T. stress The temperature at which the sample reaches isothermal equilibrium during the electromigration test. Under a constant heating rate, the stress temperature T is... stress The stress temperature is determined by the time it takes for the temperature of the sample under test to just reach the stress temperature. For example, for aluminum, the stress temperature T is... stress It is around 300℃.
[0036] The method for determining the failure distribution variance of the test sample includes: confirming whether the test sample has the failure distribution variance when it is a normal sample; if it does, then the failure distribution variance when the test sample is a normal sample is used as the failure distribution variance of the test sample. If it does not have the failure distribution variance when the test sample is a normal sample, then the value of the failure distribution variance of the test sample is not greater than 1.2. For example, the failure distribution variance of the test sample is 1.2.
[0037] Based on the failure distribution variance, the stress temperature T is obtained. stress The stress test time t under the aforementioned practical application conditions. stress The stress test time t stress The temperature of the sample to be tested is just at the stress temperature T. stress The time until the end of the electromigration test. The stress test time t. stress The methods for determining this may include:
[0038] S21: Based on the Black equation and the electromigration failure distribution density function, a universal relationship is obtained between lifetime and failure time when cumulative failure equals 50%;
[0039] S22: Based on the universal relationship, extrapolate the normal lifespan lt when the test sample is a normal sample to obtain the normal lifespan lt. baseline，yr Failure time t when cumulative failure equals 50% baseline，yr，50 The first relationship between them, and the lifetime of the test sample under practical application conditions. spec，yr Failure time t when cumulative failure equals 50% spec，yr，50 The second relationship between them;
[0040] S23: Process the first relationship and the second relationship to obtain the t spec，yr，50 With the t baseline，yr，50 lt baseline，yr and lt spec，yr A third relationship between them;
[0041] S24: Process the universal relation and the third relation to obtain the stress test time t. stress .
[0042] In step S21, the Black equation is: t 50 =A×J -n ×EXP(E a / kT), where t 50 Let A be the failure time when the cumulative failure rate equals 50%, A be the structure function related to the interconnect material properties, J be the current density under accelerated conditions, n be the acceleration factor of the current density, Ea be the equivalent diffusion activation energy during the electromigration failure process of the interconnect material, k be the Boltzmann constant, and T be the temperature under accelerated conditions.
[0043] The electromigration failure distribution density function is:
[0044]
[0045] Wherein, PDF(t) is the failure probability density function, t is the failure time; σ is the variance of the failure distribution, t 50 This is the failure time when the cumulative failure rate equals 50%.
[0046] The universal relationship obtained from the Black equation and the electromigration failure distribution density function is: lt=AFT×AFJ×t 50 ×EXP[σ×Φ -1 [(CDF)], where 1t is the lifetime, AFT is the temperature stress acceleration factor, AFJ is the current stress density acceleration factor, and t 50 The failure time is defined as the time when the cumulative failure rate equals 50%, σ is the variance of the failure distribution of the sample under test, and Φ is the failure time. -1 (CDF) is the inverse function of the cumulative failure distribution function.
[0047] According to step S22, the normal lifetime lt when the test sample is a normal sample is obtained by extrapolation from the universal relation. baseline，yr Failure time t when cumulative failure equals 50% baseline，yr，50 The first relationship between them: lt baseline，yr =AFTxAFJ×t baseline，yr，50 ×EXP[σ×Φ -1 (CDF)]. The lifetime of the test sample under practical application conditions can also be obtained by extrapolation using universal relations. spec，yr Failure time t when cumulative failure equals 50% spec，yr，50 The second relationship between them: lt spec，yr =AFT×AFJ×t spec，yr，50 ×EXP[σ×Φ -1 (CDF)
[0048] Proceed to step S23, by processing the first and second relations, to obtain the t. spec，yr，50 With the t baseline，yr，50 lt baseline，yr and lt spec，yr The third relationship between them: t spec，yr，50 =t baseline，yr，50 ×lt spec，yr / lt baseline，yr .
[0049] Finally, step S24 is performed to process the universal relation and the third relation to obtain the stress test time t. stress :t stress =lt spec，yr / [AFT×AFJ×EXP(σ*Φ -1 (CDF)
[0050] In some embodiments, the temperature stress acceleration factor (AFT) is obtained by the following method:
[0051] AFT = EXP{E a / k[1 / (T op +273)-1 / (T stress +273)]};
[0052] Among them, E a T is the equivalent diffusion activation energy during the electromigration failure process of interconnect materials, where k is the Boltzmann constant. op T represents the temperature of the actual application scenario of the sample to be tested. stress The stress temperature.
[0053] In some embodiments, the current stress density acceleration factor AFJ is obtained by the following method:
[0054] AFJ=(J op / J stress ) -n ;
[0055] Among them, J op J represents the current density in the actual application scenario of the sample under test. stress denoted as the current density for the electromigration test, and n is the acceleration factor for the current density.
[0056] Based on the time t when the temperature of the sample under test just reaches the stress temperature st Stress test time t stress And under the same electromigration test conditions, the time t when the resistance of the test sample reaches the failure reference. shift The electromigration test time t can be obtained, and tstress+ t st ≤t<t shift In other words, the minimum value of the electromigration test time t is... min equal to t st With t stress The sum. Preferred t min Using the electromigration test time t as a guideline, the test time can be shortened to the maximum extent while meeting the OP specifications, and the phenomenon of card or pad burnout can also be effectively avoided. Of course, it is also possible to set t... min On the basis of this, the time period shall be appropriately extended, but not exceeding t shift In some embodiments, t shift The time when the resistance of the sample under test deviates by 3% from the initial resistance. In some embodiments, t... st The duration should not exceed 10 seconds.
[0057] After obtaining the electromigration test time, the stress temperature T is then... stress Electromigration testing is performed at the specified electromigration test time t to obtain the electromigration test results. The method for obtaining the electromigration test results may include: after the electromigration test, obtaining the electrical performance of the sample under test; if the electrical performance of the sample under test is normal, then the sample under test passes the test, i.e., the sample under test is qualified. If the electrical performance of the sample under test is abnormal, then the sample under test fails the test, i.e., the sample under test is unqualified.
[0058] It should be understood that the test sample for electromigration testing must be free of open circuits or short circuits from the outset. Therefore, before electromigration testing, the electrical performance of the test sample is usually tested to ensure that the electrical performance of the test sample for electromigration testing is normal.
[0059] In summary, after reading this application, those skilled in the art will understand that the foregoing application content is presented by way of example only and is not restrictive. Although not explicitly stated herein, those skilled in the art will understand that this application is intended to encompass various reasonable changes, improvements, and modifications to the embodiments. These changes, improvements, and modifications are all within the spirit and scope of the exemplary embodiments of this application.
[0060] It should be understood that the term "and / or" as used in this embodiment includes any or all combinations of one or more of the associated listed items. It should be understood that when an element is referred to as "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be an intermediate element.
[0061] Similarly, it should be understood that when an element such as a layer, region, or substrate is referred to as being "on" another element, it may be directly on that other element, or there may be intermediate elements present. Conversely, the term "directly" means without intermediate elements. It should also be understood that the terms "comprising," "including," "including," or "comprises," as used in this application, indicate the presence of the described features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof.
[0062] It should also be understood that although the terms first, second, third, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Therefore, without departing from the teachings of this application, a first element in some embodiments may be referred to as a second element in other embodiments. The same reference numerals or the same reference signs denote the same elements throughout the specification.
[0063] Furthermore, this application specification describes exemplary embodiments by referring to idealized exemplary cross-sectional views and / or plan views and / or perspective views. Therefore, differences from the illustrated shapes are foreseeable due to factors such as manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but should include deviations in shape caused, for example, by manufacturing processes. For instance, etched areas shown as rectangular typically have circular or curved features. Therefore, the regions shown in the figures are substantially schematic, and their shapes are not intended to illustrate the actual shape of the regions of the device, nor are they intended to limit the scope of the exemplary embodiments.
Claims
1. A method for electromigration testing, characterized in that, The electromigration test is an Iso-EM test method, which refers to applying a high-density current to reach a predetermined test temperature, maintaining the test temperature constant, and performing electromigration tests at a constant temperature, including: The actual application conditions of the sample under test, the stress temperature during electromigration testing, and the variance of the failure distribution are obtained. The actual application conditions include the current density and temperature of the sample under test in the actual application scenario and the minimum lifetime to meet a specific failure rate. The stress temperature is the temperature at which the sample under test reaches a constant temperature during the electromigration test. Based on the failure distribution variance, the stress test time t is obtained when the actual application conditions are met at the stress temperature. stress The stress test time t stress The time from when the temperature of the sample under test just reaches the stress temperature to the end of the electromigration test; Obtain the electromigration test time, and t stress +t st ≤t<t shift Where t is the electromigration test time, t st t is the time it takes for the temperature of the sample under test to just reach the stress temperature. shift Under the same electromigration test conditions, the time it takes for the resistance of the sample under test to reach the failure reference. Electromigration tests are performed at the specified stress temperature and electromigration test time to obtain electromigration test results.
2. The method for electromigration testing according to claim 1, characterized in that, Obtain the stress test time t under the stated stress temperature and the actual application conditions. stress The methods include: Based on the Black equation and the electromigration failure distribution density function, a universal relationship between lifetime and failure time when cumulative failure equals 50% is obtained. Based on the universal relationship, the normal lifespan lt when the test sample is a normal sample is obtained by extrapolation. baseline,yr Failure time t when cumulative failure equals 50% baseline,yr,50 The first relationship between them, and the lifetime of the test sample under practical application conditions. spec,yr Failure time t when cumulative failure equals 50% spec,yr,50 The second relationship between them; Process the first relation and the second relation to obtain the t spec,yr,50 With the t baseline,yr,50 lt baseline,yr and lt spec,yr A third relationship between them; By processing the universal relation and the third relation, the stress test time t is obtained. stress .
3. The method for electromigration testing according to claim 2, characterized in that, The Black equation is: t 50 =A×J -n ×EXP(E a / kT), where t 50 Let A be the failure time when the cumulative failure rate equals 50%, A be the structure function related to the interconnect material properties, J be the current density under accelerated conditions, n be the acceleration factor of the current density, and E be the failure time. a It is the equivalent diffusion activation energy during the electromigration failure process of interconnect materials, where k is the Boltzmann constant and T is the temperature under acceleration conditions; The electromigration failure distribution density function is: Wherein, PDF(t) is the failure probability density function, t is the failure time; σ is the failure distribution variance, and t50 is the failure time corresponding to when the cumulative failure is equal to 50%; The universal relation is: lt = AFT × AFJ × t 50 ×EXP[σ×Φ -1 [(CDF)], where lt is the lifetime, AFT is the temperature stress acceleration factor, AFJ is the current stress density acceleration factor, and t 50 The failure time is defined as the time when the cumulative failure rate equals 50%, σ is the variance of the failure distribution of the sample under test, and Φ is the failure time. -1 (CDF) is the inverse function of the cumulative failure distribution function.
4. The method for electromigration testing according to claim 3, characterized in that, The first relationship is: lt baseline,yr =AFT×AFJ×t baseline,yr,50 ×EXP[σ×Φ -1 (CDF)]; The second relationship is: lt spec,yr =AFT×AFJ×t spec,yr,50 ×EXP[σ×Φ -1 (CDF)]。 5. The method for electromigration testing according to claim 4, characterized in that, The third relationship is: t spec,yr,50 =t baseline,yr,50 ×lt spec,yr / lt baseline,yr 。 6. The method for electromigration testing according to claim 5, characterized in that, The stress test time t stress for: t stress =lt spec,yr / [AFT×AFJ×EXP(σ*Φ -1 (CDF))]。 7. The method for electromigration testing according to any one of claims 4 to 6, characterized in that, The temperature stress acceleration factor (AFT) is obtained by the following method: AFT=EXP{E a / k[1 / (T op +273)-1 / (T stress +273)]}; Among them, E a T is the equivalent diffusion activation energy during the electromigration failure process of interconnect materials, where k is the Boltzmann constant. op T represents the temperature of the actual application scenario of the sample to be tested. stress The stress temperature.
8. The method for electromigration testing according to any one of claims 4 to 6, characterized in that, The current stress density acceleration factor AFJ is obtained by the following method: AFJ=(J op / J stress ) -n ; Among them, J op J represents the current density in the actual application scenario of the sample under test. stress denoted as the current density for the electromigration test, and n is the acceleration factor for the current density.
9. The method for electromigration testing according to claim 1, characterized in that, The method for determining the variance of the failure distribution of the sample to be tested includes: Confirm whether the failure distribution variance exists when the sample to be tested is a normal sample; If the failure distribution variance is such that the test sample is a normal sample, then the failure distribution variance when the test sample is a normal sample is used as the failure distribution variance of the test sample.
10. The method for electromigration testing according to claim 9, characterized in that, The method for determining the failure distribution variance of the test sample further includes: if the test sample does not have the failure distribution variance when it is a normal sample, then the value of the failure distribution variance of the test sample is not greater than 1.
2.
11. The method for electromigration testing according to claim 1, characterized in that, The t st The duration should not exceed 10 seconds.
12. The method for electromigration testing according to claim 1, characterized in that, Methods for obtaining electromigration test results include: After the electromigration test is completed, the electrical performance results of the sample under test are obtained; If the electrical performance results of the sample under test are normal, then the sample under test passes the test.
13. The method for electromigration testing according to claim 12, characterized in that, If the electrical performance of the sample under test is abnormal, the sample under test fails the test.
14. The method for electromigration testing according to claim 1, characterized in that, Before conducting the electromigration test, the method further includes testing the electrical performance of the sample under test to ensure that the electrical performance of the sample under test for the electromigration test is normal.