Electromigration evaluation method, device and electronic equipment

Abstract

The present invention provides an electromigration evaluation method, device and electronic device, and relates to the field of integrated circuit technology. The method includes: obtaining the operating temperature and operating time corresponding to the integrated circuit sample in multiple application scenarios, and obtaining the target life time according to the sum of multiple operating times. Determine the electromigration temperature function of the integrated circuit sample. Use the electromigration temperature function to normalize the corresponding operating time at each operating temperature to the reference temperature to obtain a first equivalent time. Determine the first equivalent temperature based on the electromigration temperature function, the target life time and multiple first equivalent times. Perform electromigration simulation analysis on the integrated circuit sample at the first equivalent temperature to obtain simulation results, and evaluate whether there is an electromigration risk for the interconnection line in the integrated circuit sample based on the simulation results. The first equivalent temperature in the present invention is closer to the actual application temperature of the integrated circuit sample, which greatly improves the accuracy of the electromigration analysis.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuits, and in particular to an electromigration evaluation method, device and electronic equipment. Background Art

[0002] As the size of integrated circuits continues to shrink, reliability issues are becoming more and more serious. Among them, the electromigration (EM) effect, as a conventional integrated circuit reliability failure mechanism, occupies an important position in the reliability analysis of integrated circuits.

[0003] Inside the integrated circuit, the interconnection lines are divided into many layers. The same layer is connected by metal wires, and different layers are connected by vias, thereby realizing the electrical connection between the internal devices and circuits of the integrated circuit. When the current density in the metal wire / via is very large, that is, a large number of electrons will collide with metal atoms within a certain period of time, and the metal atoms will flow along the direction of the electrons. This phenomenon is the electromigration effect. Electromigration is a long-term loss phenomenon that will cause the resistance of the metal interconnection line to increase, or even open circuit and short circuit, resulting in timing or functional errors in the integrated circuit. Therefore, before running the integrated circuit, it is necessary to perform electromigration simulation checks on the interconnection lines in the integrated circuit.

[0004] The current electromigration simulation inspection method is: at a certain temperature, the actual current value I flowing through the metal line / via on the integrated circuit layout is obtained by circuit simulation, and the current constraint value at that temperature is calculated based on the physical size and design rules of the metal line / via at different levels. If a metal line / via has an I> , it indicates that the metal line / via may have electromigration risk under the circuit simulation conditions (temperature / current). Since the temperature during electromigration simulation in the prior art is set by the designer based on his own experience, there is a large difference between the simulation temperature of the interconnect and the actual application temperature, resulting in inaccurate electromigration analysis results, which may be too low or too high, thus bringing about electromigration failure risks or over-design problems, affecting the reliability of integrated circuit products.

[0005] Therefore, how to improve the accuracy of electromigration analysis and ensure the reliability of integrated circuit products is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0006] The object of the present invention is to provide an electromigration evaluation method to improve the accuracy of electromigration analysis and ensure the reliability of integrated circuit products.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] The present invention provides an electromigration assessment method for assessing the electromigration risk of interconnects in an integrated circuit sample, the method comprising:

[0009] Obtaining the operating temperature and operating time corresponding to the integrated circuit sample in multiple application scenarios, and obtaining the target life time according to the sum of the multiple operating times;

[0010] determining an electromigration temperature function of the integrated circuit sample;

[0011] Normalizing the working time corresponding to each working temperature to a reference temperature by using the electromigration temperature function to obtain a first equivalent time;

[0012] determining a first equivalent temperature based on the electromigration temperature function, the target lifetime time and a plurality of the first equivalent times;

[0013] Performing electromigration simulation analysis on the integrated circuit sample at the first equivalent temperature to obtain simulation results, and evaluating whether there is an electromigration risk for interconnects in the integrated circuit sample based on the simulation results.

[0014] Optionally, the method for determining the electromigration temperature function of the integrated circuit sample comprises:

[0015] Obtaining an electromigration temperature coefficient table corresponding to the process adopted by the integrated circuit sample;

[0016] The electromigration temperature function is established by fitting a plurality of temperature values ​​in the electromigration temperature coefficient table and the electromigration temperature coefficient corresponding to each temperature value.

[0017] Optionally, the method of normalizing the working time corresponding to each working temperature to a reference temperature by using the electromigration temperature function to obtain a first equivalent time includes:

[0018] Using the electromigration temperature function, obtaining an electromigration temperature coefficient corresponding to the reference temperature and an electromigration temperature coefficient corresponding to each of the operating temperatures;

[0019] The first equivalent time satisfies the formula:

[0020] The first equivalent time = [electromigration temperature coefficient corresponding to the reference temperature / electromigration temperature coefficient corresponding to the operating temperature] * operating time corresponding to the operating temperature.

[0021] Optionally, the method for determining the first equivalent temperature based on the electromigration temperature function, the target life time and a plurality of the first equivalent times includes:

[0022] Obtaining a second equivalent time according to the sum of a plurality of said first equivalent times;

[0023] The first equivalent temperature satisfies the formula:

[0024]

[0025] in, is the first equivalent temperature, f(T) is the electromigration temperature function, t is the target life time, is the second equivalent time.

[0026] Optionally, the method of performing electromigration simulation analysis on the integrated circuit sample at the first equivalent temperature to obtain a simulation result, and evaluating whether there is an electromigration risk of an interconnection line in the integrated circuit sample based on the simulation result includes:

[0027] Acquiring process information of the integrated circuit sample;

[0028] When the integrated circuit sample is manufactured by a three-dimensional process, an electromigration simulation analysis is performed on the integrated circuit sample at the first equivalent temperature to obtain a first simulation result, and based on the first simulation result, it is evaluated whether there is an electromigration risk for the interconnection lines in the three-dimensional process integrated circuit sample;

[0029] When the integrated circuit sample is manufactured by a planar process, an electromigration simulation analysis is performed on the integrated circuit sample at the first equivalent temperature to obtain a first average current electromigration value and a root mean square current electromigration value of the interconnect line, and based on the first average current electromigration value and the root mean square current electromigration value, it is evaluated whether there is an electromigration risk for the interconnect line in the planar process integrated circuit sample.

[0030] Optionally, the method for evaluating whether there is an electromigration risk of an interconnection line in a planar process integrated circuit sample based on the first average current electromigration value and the root mean square current electromigration value includes:

[0031] The actual self-heating temperature rise of the interconnection line is obtained based on the root mean square current electromigration value and the preset self-heating temperature rise; wherein the preset self-heating temperature rise is the temperature rise value generated by the self-heating of the interconnection line corresponding to the root mean square current electromigration value being 100%;

[0032] Obtaining a second average current electromigration value based on the electromigration temperature function, the first equivalent temperature, the actual spontaneous temperature rise, and the first average current electromigration value;

[0033] Based on the second average current electromigration value, it is evaluated whether there is an electromigration risk for interconnect lines in the planar process integrated circuit sample.

[0034] Optionally, the actual self-heating temperature rise satisfies the formula:

[0035] Actual self-heating temperature rise = root mean square current electromigration value * root mean square current electromigration value * preset self-heating temperature rise.

[0036] Optionally, a method for obtaining a second average current electromigration value based on the electromigration temperature function, the first equivalent temperature, the actual spontaneous temperature rise and the first average current electromigration value includes:

[0037] Obtaining a second equivalent temperature according to the sum of the first equivalent temperature and the actual self-heating temperature rise;

[0038] Obtaining an electromigration temperature coefficient corresponding to the first equivalent temperature and an electromigration temperature coefficient corresponding to the second equivalent temperature by using the electromigration temperature function;

[0039] The second average current electromigration value satisfies the formula:

[0040] The second average current electromigration value=(the first average current electromigration value*the electromigration temperature coefficient corresponding to the first equivalent temperature) / the electromigration temperature coefficient corresponding to the second equivalent temperature.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] The present invention provides an electromigration evaluation method. By collecting application scenarios of integrated circuit samples, the operating temperature and working time corresponding to each application scenario are obtained. Under the determined target life time and reference temperature, the first equivalent temperature is calculated using the electromigration temperature function, and the first equivalent temperature is set as the temperature of the electromigration analysis of the integrated circuit sample and a simulation analysis is performed. Compared with the prior art, since the first equivalent temperature is obtained after normalization and other operations based on the operating temperature and working time of the integrated circuit sample in multiple application scenarios, the target life time, the reference temperature and the electromigration temperature function, the first equivalent temperature is closer to the actual application temperature of the integrated circuit sample, thereby improving the accuracy of the electromigration analysis results and ensuring the reliability of the integrated circuit sample.

[0043] In addition, the present invention also considers the influence of the heating of the interconnection line on the electromigration results during the actual application of the integrated circuit sample. In particular, for the planar process integrated circuit sample, the present invention performs a correlation calculation on the first average current electromigration value and the root mean square current electromigration value output by the simulation to obtain the second average current electromigration value, and finally evaluates whether the interconnection line in the planar process integrated circuit sample has the electromigration risk according to the second average current electromigration value, further improving the accuracy of the electromigration analysis results and effectively ensuring the reliability of the integrated circuit sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the present invention will be briefly introduced below. It should be understood that the following drawings only show certain technical solutions of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 A flow chart of an electromigration evaluation method provided by the present invention;

[0046] Figure 2 It is a schematic diagram of the steps of step 300 in the present invention;

[0047] Figure 3 It is a schematic diagram of the steps of step 400 in the present invention;

[0048] Figure 4 It is a schematic diagram of the steps of step 500 in the present invention;

[0049] Figure 5 It is a schematic diagram of the steps of step 530 in the present invention;

[0050] Figure 6 It is a schematic diagram of the steps of step 532 in the present invention;

[0051] Figure 7 A schematic structural diagram of an electromigration evaluation device provided by the present invention.

[0052] Reference numerals: 10 - electromigration evaluation device; 11 - acquisition module; 12 - first determination module; 13 - normalization module; 14 - second determination module; 15 - evaluation module. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described technical solutions are part of the technical solutions of the present invention, but not all of the technical solutions. Generally, the components of the technical solutions of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0054] Therefore, the following detailed description of the technical solutions of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents the selected technical solutions of the present invention. Based on the technical solutions in the present invention, all other technical solutions obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0055] In the description of the present invention, terms such as "first", "second" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance. It should be noted that the features of the present invention can be combined with each other without conflict.

[0056] As mentioned in the technical background, the existing electromigration simulation method is to simulate and check the integrated circuit products at a certain temperature. Since the temperature is set by the designer based on his own experience, there is a large difference from the actual application temperature of the integrated circuit product, resulting in the electromigration analysis result being too low or too high. If the electromigration analysis result is too low, there is a risk of electromigration failure. If the electromigration analysis result is too high, there is a problem of over-design and waste of design resources, which affects the reliability of the integrated circuit product.

[0057] Therefore, how to improve the accuracy of electromigration analysis and ensure the reliability of integrated circuit products is a technical problem that needs to be solved urgently by those skilled in the art.

[0058] To solve the above technical problems, please refer to Figure 1 The embodiment of the present invention provides an electromigration assessment method for assessing the electromigration risk of interconnects in an integrated circuit sample. The method comprises the following steps:

[0059] Step 100: Obtain the operating temperature and operating time corresponding to the integrated circuit sample in multiple application scenarios, and obtain the target life time according to the sum of multiple operating times.

[0060] In order to make the temperature of electromigration simulation closer to the actual application temperature of the integrated circuit sample, in an embodiment of the present invention, it is necessary to collect the application scenarios of the integrated circuit sample and obtain the operating temperature and operating time corresponding to the integrated circuit sample in each application scenario.

[0061] Among them, the operating temperature refers to the temperature of the integrated circuit sample when it works in a certain application scenario, and the working time refers to the continuous working time of the integrated circuit sample at the corresponding operating temperature. That is, each application scenario corresponds to an operating temperature and a working time.

[0062] The target life time is obtained according to the application requirements of the integrated circuit sample, that is, the target life time is the sum of the working time of the integrated circuit sample in multiple different application scenarios (that is, multiple different working temperatures).

[0063] Step 200: Determine the electromigration temperature function of the integrated circuit sample.

[0064] Based on the design documents provided by the foundry, a table of electromigration temperature coefficients corresponding to the process used by the integrated circuit sample can be obtained.

[0065] Among them, the electromigration temperature coefficient table shows the electromigration temperature coefficient corresponding to the integrated circuit sample at different temperature values. However, since the temperature values ​​in the electromigration temperature coefficient table and the corresponding electromigration temperature coefficient values ​​are discrete, in actual application, it is impossible to obtain the electromigration temperature coefficient corresponding to the integrated circuit sample at any temperature by looking up the table.

[0066] In order to solve the above problem, in an embodiment of the present invention, a continuous electromigration temperature function can be obtained by fitting multiple temperature values ​​in the electromigration temperature coefficient table and the electromigration temperature coefficient corresponding to each temperature value. The electromigration temperature coefficient corresponding to the integrated circuit sample at any temperature can be obtained through the electromigration temperature function.

[0067] It should be noted that the electromigration temperature function is used to characterize the relationship between the electromigration effect and temperature. That is, the higher the temperature, the smaller the corresponding electromigration temperature coefficient (the weaker the metal current carrying capacity), and the more obvious the electromigration effect of the metal interconnect in the integrated circuit sample.

[0068] Step 300: normalize the working time corresponding to each working temperature to a reference temperature using an electromigration temperature function to obtain a first equivalent time.

[0069] Step 400: Determine a first equivalent temperature based on an electromigration temperature function, a target lifetime, and a plurality of first equivalent times.

[0070] Step 500: Perform electromigration simulation analysis on an integrated circuit sample at a first equivalent temperature to obtain simulation results, and evaluate whether there is an electromigration risk for interconnects in the integrated circuit sample based on the simulation results.

[0071] Based on the above steps, the present invention collects the operating temperatures and operating times corresponding to integrated circuit samples in multiple application scenarios, and uses the electromigration temperature function to normalize the operating time under multiple different operating temperatures (i.e., multiple different application scenarios), thereby eliminating the errors caused by temperature fluctuations in different application scenarios, making the data in different application scenarios more comparable, and ensuring the subsequent formation of more comprehensive electromigration analysis results.

[0072] Compared with the prior art, since the first equivalent temperature obtained by the present invention based on the electromigration temperature function, the target life time and multiple first equivalent times is closer to the actual application temperature of the integrated circuit sample, the electromigration analysis result obtained by electromigration simulation of the integrated circuit sample at the first equivalent temperature is more accurate, and the reliability of the integrated circuit sample is effectively guaranteed.

[0073] To better understand the technical solution of the present invention, please refer to Figure 2The specific steps of normalization processing are described below. That is, the step 300 of normalizing the working time corresponding to each working temperature to the reference temperature using the electromigration temperature function to obtain the first equivalent time includes the following steps:

[0074] Step 310: Obtain an electromigration temperature coefficient corresponding to a reference temperature and an electromigration temperature coefficient corresponding to each operating temperature using an electromigration temperature function.

[0075] Step 320: The first equivalent time satisfies the following formula:

[0076] The first equivalent time = [electromigration temperature coefficient corresponding to the reference temperature / electromigration temperature coefficient corresponding to the operating temperature] * operating time corresponding to the operating temperature.

[0077] Exemplarily, it is assumed that the electromigration temperature coefficient table corresponding to the process adopted by the integrated circuit sample is shown in Table 1.

[0078] Table 1 Electromigration temperature coefficient table

[0079]

[0080] The temperature values ​​and the electromigration temperature coefficient values ​​in the electromigration temperature coefficient table are fitted to establish the electromigration temperature function f(T).

[0081] Assume that the integrated circuit sample has three application scenarios, and the corresponding operating temperatures and working times are as follows:

[0082] Application scenario 1: operating temperature is 125 , working hours are Hour;

[0083] Application scenario 2: Working temperature is 120 , working hours are Hour;

[0084] Application scenario three: operating temperature is 115 , working hours are Hour.

[0085] It should be noted that the reference temperature can take any value, and the present invention does not limit this. However, in order to facilitate the subsequent calculation of the first equivalent time, the reference temperature can take the temperature value when the electromigration temperature coefficient is 1, that is, the reference temperature is selected to be 110 .

[0086] Using the electromigration temperature function f(T) to obtain 110 The corresponding electromigration temperature coefficient is 1.125 The corresponding electromigration temperature coefficients are 0.36 and 120 The corresponding electromigration temperature coefficients are 0.5 and 115 The corresponding electromigration temperature coefficient is 0.7.

[0087] According to the above data and the calculation formula of the first equivalent time, the application scenario is normalized to 110 The first equivalent time under = [1 / 0.36]* =2.78 .

[0088] Similarly, normalize the application scenario 2 to 110 The first equivalent time under = [1 / 0.5]* =2 .

[0089] Normalize the application scenario three to 110 The first equivalent time under = [1 / 0.7]* =1.43 .

[0090] It can be seen that the electromigration temperature function can be used to normalize the corresponding working time in the three application scenarios to the reference temperature, thereby obtaining the three first equivalent times (i.e., 2.78 , 2 , 1.43 ).

[0091] After obtaining a plurality of first equivalent times, it is also necessary to determine the first equivalent temperature according to the electromigration temperature function and the target life time.

[0092] Specifically, see Figure 3 The step 400 of determining the first equivalent temperature based on the electromigration temperature function, the target life time and a plurality of first equivalent times comprises the following steps:

[0093] Step 410: Obtain a second equivalent time according to the sum of multiple first equivalent times.

[0094] Step 420: The first equivalent temperature satisfies the following formula:

[0095]

[0096] in, is the first equivalent temperature, f(T) is the electromigration temperature function, t is the target life time, is the second equivalent time.

[0097] That is, when the independent variable T in f(T)= When , the value of f(T) = .

[0098] Exemplarily, the target life time t of the integrated circuit sample is + + , the second equivalent time =2.78 +2 +1.43 Due to the expression of electromigration temperature function f(T), target life time t and second equivalent time are all known, so we establish the equation , the T value obtained after solving the equation is the first equivalent temperature .

[0099] Since the first equivalent temperature in the embodiment of the present invention is obtained based on the working temperature and working time of the integrated circuit sample in different application scenarios, the target life time, the reference temperature, and the electromigration temperature function after normalization and other operations, the first equivalent temperature is closer to the actual application temperature of the integrated circuit sample. The electromigration analysis result obtained by performing electromigration simulation on the integrated circuit sample at the first equivalent temperature is more accurate, ensuring the reliability of the integrated circuit sample.

[0100] In addition, when the semiconductor devices (such as transistors) in the integrated circuit have current passing through them during operation, heat is generated, which may cause temperature differences in different areas of the integrated circuit. As the semiconductor process has evolved from a planar process to a three-dimensional process, the heating of transistors has become more serious. Since transistors with a planar structure have better heat dissipation than transistors with a three-dimensional structure, the industry has heat-related electromigration analysis for integrated circuits with a three-dimensional process. However, for integrated circuits with a planar process, the prior art does not consider the effect of the self-heating of transistors (i.e., device heating) on ​​the electromigration effect of metal lines / vias, and correspondingly does not consider the effect of the self-heating (i.e., metal line heating) generated by the current flowing through the metal lines on the electromigration effect of metal lines / vias.

[0101] When the actual circuit is running, whether it is a planar process integrated circuit or a three-dimensional process integrated circuit, due to the heating of the device and the heating of the metal wire, the temperature of the metal interconnection wires in different areas of the integrated circuit may have a large temperature difference, and correspondingly, the current density constraint value is also different. Therefore, in order to further improve the accuracy of electromigration analysis, it is also necessary to consider the impact of device heating and metal wire heating in the integrated circuit on the electromigration effect.

[0102] Specifically, see Figure 4 The step 500 of performing electromigration simulation analysis on the integrated circuit sample at a first equivalent temperature to obtain simulation results, and evaluating whether there is an electromigration risk of the interconnection line in the integrated circuit sample based on the simulation results includes the following steps:

[0103] Step 510: Obtain process information of the integrated circuit sample.

[0104] Step 520: When the integrated circuit sample is manufactured by a three-dimensional process, an electromigration simulation analysis is performed on the integrated circuit sample at a first equivalent temperature to obtain a first simulation result, and based on the first simulation result, it is evaluated whether there is an electromigration risk for the interconnection lines in the three-dimensional process integrated circuit sample.

[0105] For three-dimensional process integrated circuits, when performing electromigration simulation analysis at the first equivalent temperature, calculations can be directly performed based on the thermal analysis method and model provided by the foundry to obtain the first simulation result, and based on the first simulation result, it can be evaluated whether there is an electromigration risk for the interconnect lines in the three-dimensional process integrated circuit sample.

[0106] Step 530: When the integrated circuit sample is manufactured by a planar process, an electromigration simulation analysis is performed on the integrated circuit sample at a first equivalent temperature to obtain a first average current electromigration value and a root mean square current electromigration value of the interconnection line, and based on the first average current electromigration value and the root mean square current electromigration value, it is evaluated whether there is an electromigration risk for the interconnection line in the planar process integrated circuit sample.

[0107] For planar process integrated circuit samples, although the heat dissipation of the bottom transistors has little effect, the self-heating generated by the current flowing through the metal wire itself will cause a certain temperature rise on the metal wire itself and the surrounding metal. Therefore, in order to further improve the accuracy of electromigration analysis results, it is necessary to focus on the impact of metal wire heating in planar process integrated circuit samples.

[0108] In the electromigration simulation analysis of integrated circuits, EDA tools can output average current electromigration values ​​(AVG EM) and root mean square current electromigration values ​​(RMS EM) based on different forms of current waveforms. Among them, the average current electromigration value is strongly correlated with temperature, representing the impact of the long-term average effect of current on life. The root mean square current electromigration value represents the self-heating effect of current flowing through the metal wire.

[0109] For planar process integrated circuits, after performing electromigration simulation analysis at the first equivalent temperature, the first average current electromigration value and the root mean square current electromigration value of the interconnection can be obtained. Since the metal interconnection heats up during the electromigration simulation analysis of the planar process integrated circuit, the interconnection generates a self-heating temperature rise. Therefore, it is also necessary to perform a correlation calculation based on the first average current electromigration value and the root mean square current electromigration value to evaluate whether there is an electromigration risk for the interconnection in the planar process integrated circuit sample.

[0110] Specifically, see Figure 5 The step 530 of evaluating whether there is an electromigration risk of an interconnection line in a planar process integrated circuit sample based on the first average current electromigration value and the root mean square current electromigration value includes the following steps:

[0111] Step 531 : obtaining the actual self-heating temperature rise of the interconnection line based on the RMS current electromigration value and the preset self-heating temperature rise.

[0112] The preset self-heating temperature rise is the temperature rise value caused by the self-heating of the interconnection line corresponding to the root mean square current electromigration value of 100%.

[0113] The actual self-heating temperature rise satisfies the following formula:

[0114] Actual self-heating temperature rise = root mean square current electromigration value * root mean square current electromigration value * preset self-heating temperature rise.

[0115] For example, assuming that the preset self-heating temperature rise is 5 (That is, when the RMS current electromigration value is 100%, the corresponding interconnection line self-heating temperature rise is 5 ), the RMS current electromigration value is 150%, then the actual self-heating temperature rise of the interconnect = 150%*150%*5=11.25 .

[0116] Step 532 : Obtain a second average current electromigration value based on the electromigration temperature function, the first equivalent temperature, the actual spontaneous temperature rise, and the first average current electromigration value.

[0117] Specifically, see Figure 6 The step 532 of obtaining the second average current electromigration value based on the electromigration temperature function, the first equivalent temperature, the actual self-heating temperature rise and the first average current electromigration value includes the following steps:

[0118] Step 5321: Obtain a second equivalent temperature based on the sum of the first equivalent temperature and the actual self-heating temperature rise.

[0119] That is to say, the second equivalent temperature = the first equivalent temperature + the actual self-heating temperature rise.

[0120] Step 5322: Obtain an electromigration temperature coefficient corresponding to the first equivalent temperature and an electromigration temperature coefficient corresponding to the second equivalent temperature using the electromigration temperature function.

[0121] Step 5323: The second average current electromigration value satisfies the following formula:

[0122] The second average current electromigration value=(the first average current electromigration value*the electromigration temperature coefficient corresponding to the first equivalent temperature) / the electromigration temperature coefficient corresponding to the second equivalent temperature.

[0123] In the embodiment of the present invention, the electromigration temperature coefficient corresponding to any temperature value can be obtained by using the electromigration temperature function obtained previously. Therefore, if the first average current electromigration value at the first equivalent temperature is known, to obtain the second average current electromigration value at the second equivalent temperature, it is only necessary to perform electromigration temperature coefficient conversion.

[0124] For example, assuming that the first equivalent temperature is 115 , the corresponding first average current electromigration value is 100%, and the second equivalent temperature is 120 .

[0125] Then, the electromigration temperature function is used to obtain 115 The corresponding electromigration temperature coefficient is 0.7, and the electromigration temperature function is used to obtain 120 The corresponding electromigration temperature coefficient is 0.5.

[0126] That is, a certain interconnection line in the integrated circuit sample is 115 The first average current electromigration value under 120 is 100%, then The second average current electromigration value under = (100%*0.7) / 0.5 = 140%.

[0127] Step 533: Evaluate whether there is an electromigration risk for interconnects in the planar process integrated circuit sample based on the second average current electromigration value.

[0128] The present invention performs correlation calculation on the first average current electromigration value and the root mean square current electromigration value, and after step 531 and step 532, a new average current electromigration value, ie, the second average current electromigration value, is obtained.

[0129] According to the second average current electromigration value, it is evaluated whether the interconnection line in the planar process integrated circuit sample has an electromigration risk. If there is an electromigration risk, the circuit or layout is modified and the simulation is iterated to improve the reliability of the integrated circuit.

[0130] It can be seen that the present invention performs electromigration simulation at the first equivalent temperature for both planar process integrated circuit samples and three-dimensional process integrated circuit samples. Since the first equivalent temperature is obtained after normalization and other operations based on the operating temperature and operating time, target life time, reference temperature, and electromigration temperature function of the integrated circuit sample in different application scenarios, the first equivalent temperature is closer to the actual application temperature of the integrated circuit sample, thereby improving the accuracy of the electromigration analysis results.

[0131] In addition, the present invention also considers the influence of the heating of the interconnection line on the electromigration results during the actual application of the integrated circuit sample. In particular, for the planar process integrated circuit sample, the present invention correlates the first average current electromigration value and the root mean square current electromigration value output by the simulation tool to obtain the second average current electromigration value, and finally evaluates whether the interconnection line in the planar process integrated circuit sample has the electromigration risk according to the second average current electromigration value, further improving the accuracy of the electromigration analysis results and effectively ensuring the reliability of the integrated circuit sample.

[0132] Based on the above implementation, please refer to Figure 7 The embodiment of the present invention further provides an electromigration evaluation device 10, the electromigration evaluation device 10 comprising:

[0133] The acquisition module 11 is used to obtain the operating temperature and operating time corresponding to the integrated circuit sample in multiple application scenarios, and obtain the target life time according to the sum of multiple operating times.

[0134] The first determination module 12 is used to determine the electromigration temperature function of the integrated circuit sample.

[0135] The normalization module 13 is used to normalize the corresponding working time at each working temperature to the reference temperature by using the electromigration temperature function to obtain a first equivalent time.

[0136] The second determination module 14 is configured to determine a first equivalent temperature based on the electromigration temperature function, the target life time and a plurality of first equivalent times.

[0137] The evaluation module 15 is used to perform electromigration simulation analysis on the integrated circuit sample at a first equivalent temperature to obtain simulation results, and evaluate whether there is an electromigration risk for interconnects in the integrated circuit sample based on the simulation results.

[0138] Optionally, an embodiment of the present invention further provides an electronic device, including a processor and a memory, wherein the memory stores a program executable by the processor, and the processor can execute the program to implement the above-mentioned electromigration evaluation method.

[0139] In summary, the present invention provides an electromigration evaluation method, device and electronic device. The method comprises: collecting application scenarios of integrated circuit samples, and obtaining the operating temperature and working time corresponding to each application scenario. Under the determined target life time and reference temperature, the first equivalent temperature is calculated using the electromigration temperature function, and the first equivalent temperature is set as the temperature of the electromigration analysis of the integrated circuit sample and a simulation analysis is performed.

[0140] Compared with the prior art, the present invention performs electromigration simulation at the first equivalent temperature for both planar process integrated circuit samples and three-dimensional process integrated circuit samples. Since the first equivalent temperature is obtained after normalization and other operations based on the operating temperature and operating time, target life time, reference temperature and electromigration temperature function of the integrated circuit sample in different application scenarios, the first equivalent temperature is closer to the actual application temperature of the integrated circuit sample, thereby improving the accuracy of the electromigration analysis results.

[0141] In addition, the present invention also considers the influence of the heating of the interconnection line on the electromigration result during the actual application of the integrated circuit sample. In particular, for the planar process integrated circuit sample, the present invention performs a correlation calculation on the first average current electromigration value and the root mean square current electromigration value of the simulation output. Specifically, the actual self-heating temperature rise of the interconnection line is obtained according to the root mean square current electromigration value, and a new average current electromigration value, that is, the second average current electromigration value, is obtained according to the actual self-heating temperature rise, the first average current electromigration value, the electromigration temperature function and the first equivalent temperature. Finally, the second average current electromigration value is used to evaluate whether there is an electromigration risk for the interconnection line in the planar process integrated circuit sample, which further improves the accuracy of the electromigration analysis results and effectively ensures the reliability of the integrated circuit sample.

[0142] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0143] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. An electromigration evaluation method, characterized in that: For evaluating the electromigration risk of interconnects in an integrated circuit sample, the method comprises: Obtaining the operating temperature and operating time corresponding to the integrated circuit sample in multiple application scenarios, and obtaining the target life time according to the sum of the multiple operating times; determining an electromigration temperature function of the integrated circuit sample; Normalizing the working time corresponding to each working temperature to a reference temperature by using the electromigration temperature function to obtain a first equivalent time; determining a first equivalent temperature based on the electromigration temperature function, the target lifetime time and a plurality of the first equivalent times; Acquiring process information of the integrated circuit sample; When the integrated circuit sample is manufactured by a three-dimensional process, an electromigration simulation analysis is performed on the integrated circuit sample at the first equivalent temperature to obtain a first simulation result, and based on the first simulation result, it is evaluated whether there is an electromigration risk for interconnects in the three-dimensional process integrated circuit sample; When the integrated circuit sample is made by planar process, the electromigration simulation analysis is performed on the integrated circuit sample at the first equivalent temperature to obtain a first average current electromigration value and a root mean square current electromigration value of the interconnection line; the actual spontaneous heating temperature rise of the interconnection line is obtained based on the root mean square current electromigration value and the preset spontaneous heating temperature rise, wherein the preset spontaneous heating temperature rise is the temperature rise value generated by the self-heating of the interconnection line corresponding to the root mean square current electromigration value of 100%; the second average current electromigration value is obtained based on the electromigration temperature function, the first equivalent temperature, the actual spontaneous heating temperature rise and the first average current electromigration value; based on the second average current electromigration value, it is evaluated whether there is an electromigration risk for the interconnection line in the planar process integrated circuit sample.

2. The electromigration evaluation method according to claim 1, characterized in that: The method for determining the electromigration temperature function of the integrated circuit sample comprises: Obtaining an electromigration temperature coefficient table corresponding to the process adopted by the integrated circuit sample; The electromigration temperature function is established by fitting a plurality of temperature values ​​in the electromigration temperature coefficient table and the electromigration temperature coefficient corresponding to each temperature value.

3. The electromigration evaluation method according to claim 2, characterized in that: The method of normalizing the working time corresponding to each working temperature to a reference temperature by using the electromigration temperature function to obtain a first equivalent time includes: Using the electromigration temperature function, obtaining an electromigration temperature coefficient corresponding to the reference temperature and an electromigration temperature coefficient corresponding to each of the operating temperatures; The first equivalent time satisfies the formula: The first equivalent time = [electromigration temperature coefficient corresponding to the reference temperature / electromigration temperature coefficient corresponding to the operating temperature] * operating time corresponding to the operating temperature.

4. The electromigration evaluation method according to claim 3, characterized in that: The method for determining the first equivalent temperature based on the electromigration temperature function, the target life time and a plurality of the first equivalent times comprises: Obtaining a second equivalent time according to the sum of a plurality of said first equivalent times; The first equivalent temperature satisfies the formula: in, is the first equivalent temperature, f(T) is the electromigration temperature function, t is the target life time, is the second equivalent time.

5. The electromigration evaluation method according to claim 1, characterized in that: The actual self-heating temperature rise satisfies the formula: Actual self-heating temperature rise = root mean square current electromigration value * root mean square current electromigration value * preset self-heating temperature rise.

6. The electromigration evaluation method according to claim 1, characterized in that: The method for obtaining a second average current electromigration value based on the electromigration temperature function, the first equivalent temperature, the actual self-heating temperature rise and the first average current electromigration value includes: Obtaining a second equivalent temperature according to the sum of the first equivalent temperature and the actual self-heating temperature rise; Obtaining an electromigration temperature coefficient corresponding to the first equivalent temperature and an electromigration temperature coefficient corresponding to the second equivalent temperature by using the electromigration temperature function; The second average current electromigration value satisfies the formula: The second average current electromigration value=(the first average current electromigration value*the electromigration temperature coefficient corresponding to the first equivalent temperature) / the electromigration temperature coefficient corresponding to the second equivalent temperature.

7. An electromigration evaluation device, characterized in that: Used to perform the electromigration evaluation method according to any one of claims 1 to 6, the device comprising: An acquisition module, used to acquire the operating temperature and operating time corresponding to the integrated circuit sample in multiple application scenarios, and obtain the target life time according to the sum of the multiple operating times; A first determination module, configured to determine an electromigration temperature function of the integrated circuit sample; A normalization module, used for normalizing the working time corresponding to each working temperature to a reference temperature by using the electromigration temperature function, so as to obtain a first equivalent time; A second determination module, configured to determine a first equivalent temperature based on the electromigration temperature function, the target life time and a plurality of the first equivalent times; An evaluation module is used to perform electromigration simulation analysis on the integrated circuit sample at the first equivalent temperature to obtain simulation results, and evaluate whether there is an electromigration risk for interconnects in the integrated circuit sample based on the simulation results.

8. An electronic device, characterized in that: The invention comprises a processor and a memory, wherein the memory stores a program executable by the processor, and the processor can execute the program to implement the electromigration evaluation method according to any one of claims 1 to 6.

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