Test structure and test method for intermetallic coupling heat
By designing a metal interlayer coupling thermal test structure and using the temperature coefficient of resistance (TCR) of the temperature-sensitive metal wire and the heat source metal wire to quickly evaluate the interlayer coupling thermal effect, the problem of long test cycle and lack of measured data in the existing technology is solved, and rapid evaluation and support for the selection of dielectric materials are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI HUALI INTEGRATED CIRCUIT CORP
- Filing Date
- 2026-03-25
- Publication Date
- 2026-06-09
AI Technical Summary
Existing reliability testing methods for metal interconnect layers require testing cycles of hundreds of hours, which cannot meet the needs of rapid online monitoring, and lack simulation schemes for verifying the thermal coupling effects between metal layers with actual measurement data.
A test structure for intermetallic coupled heat is designed, including a temperature-sensitive metal wire and a heat source metal wire. By applying constant current and current stress at different temperatures, the temperature coefficient of resistance (TCR) is calculated, and the resistance value is measured in real time to evaluate the coupled heat effect between metal layers.
It enables rapid qualitative analysis of interlayer coupling heat in metals, evaluates the thermal diffusion capability of the medium, supports the selection of interlayer dielectric materials and the development of new manufacturing processes, and provides data verification for simulation technology.
Smart Images
Figure CN122171616A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to semiconductor manufacturing technology, and in particular to a test structure and test method for interlayer coupling heat in metals. Background Technology
[0002] As large-scale integrated circuits advance towards the deep submicron era, the controllable range of the manufacturing process becomes increasingly narrow, and the requirements for integrated circuit reliability continue to rise. Integrated circuit manufacturers need more online, real-time monitoring methods to ensure yield and product reliability on the production line. Because the capacity requirements for integrated circuit components are increasing while the chip size requirements are decreasing, metal interconnect layers play an increasingly important role in product reliability. Chip-level stress migration testing, isothermal electromigration testing, and package-level testing are the main methods for monitoring the reliability of metal interconnect layers. However, their common problem is that they require test cycles of hundreds or even thousands of hours, which is unacceptable for rapid online monitoring requirements. In semiconductors, the temperature coefficient of resistance (TCR) is used to characterize the relationship between the resistance of a metal and its temperature. The temperature coefficient of resistance represents the relative change in resistance (resistivity) per unit temperature change. As a parameter reflecting the change in resistance with temperature, the temperature coefficient of resistance is widely used in the reliability testing of metal interconnects. The temperature coefficient of resistance is related to the microstructure of the metal interconnect layer and has a strong correlation with the results of electromigration tests. The temperature coefficient of resistance can serve as an early parameter for monitoring the reliability of metal interconnect layers, enabling early predictions of process development and product verification.
[0003] The primary task of back-end of the line (BEOL) semiconductor manufacturing is to construct metal interconnect structures, connecting transistors manufactured in the front-end processes into complete circuits. As integrated circuit manufacturing technology continues to evolve, the linewidth of metal interconnects is shrinking, and the layers of back-end metal wiring are becoming increasingly complex. The increased line density leads to significant thermal effects in the metal interconnect layers, and the accumulation of heat degrades the reliability of the interconnects. How to assess the coupling thermal effects between metal interconnect layers is a pressing issue for current process technologies, but existing simulation schemes lack empirical data for verification. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to provide a test structure and test method for interlayer coupling heat of metals, which can quickly and qualitatively analyze the interlayer coupling heat of metals.
[0005] To solve the above-mentioned technical problems, the present invention provides a test structure for interlayer coupling heat of metal, which includes a temperature-sensitive metal wire 11 and N heat source metal wires 12, where N is a positive integer; The temperature-sensitive metal wire 11 and the N heat source metal wires 12 are located in different metal layers and distributed in N+1 metal layers; The transverse wiring direction of one temperature-sensitive metal wire 11 and N heat source metal wires 12 is consistent; A temperature-sensitive metal wire 11 and N heat source metal wires 12 have a common overlapping area in their vertical projections; One end of each of the N heat source metal wires 12 is shorted to the same heat source contact pad, and the other end is shorted to different heat source contact pads respectively. One end of a temperature-sensitive metal wire 11 is shorted to the second temperature-sensitive contact pad, and the other end is shorted to the fourth temperature-sensitive contact pad.
[0006] Preferably, the test structure for evaluating inter-metal coupling heat is fabricated in the back-end process of semiconductor device manufacturing.
[0007] Preferably, when N is greater than 1, the metal layer containing a temperature-sensitive metal wire 11 is located between the metal layers containing two adjacent heat source metal wires 12.
[0008] Ideally, N should be 2.
[0009] Preferably, the heat source metal wire 12 is made of aluminum, copper, tungsten, tantalum or manganese.
[0010] Preferably, the temperature-sensitive metal wire 11 is made of aluminum or copper.
[0011] To solve the above-mentioned technical problems, the present invention provides a metal interlayer coupling thermal testing method using the aforementioned test structure, comprising the following steps: S1. Apply a constant current to the temperature-sensitive metal wire 11 at different test temperatures, and calculate the temperature coefficient of resistance (TCR) of the temperature-sensitive metal wire 11 based on the relative change in resistance of the temperature-sensitive metal wire 11 at different temperatures. At a set ambient temperature, current is applied to each heat source metal wire 12 for a set duration, and the resistance value of the temperature-sensitive metal wire 11 is measured in real time; the current applied to each heat source metal wire 12 is changed, and the resistance values of m temperature-sensitive metal wires 11 corresponding to m sets of currents are measured in real time. Each set of currents consists of N currents applied to N heat source metal wires 12, where m is a positive integer. S2. Based on the temperature coefficient of resistance (TCR) of the temperature-sensitive metal wire 11 obtained in step S1 and the m resistance values of the temperature-sensitive metal wire 11 corresponding to the m sets of currents, calculate the m temperature changes in the metal layer where the temperature-sensitive metal wire is located due to the coupled thermal effect corresponding to the m sets of currents. , This is the real-time measured resistance value of the temperature-sensitive metal wire when no current is applied to the heat source metal wire 12 at the set ambient temperature; i is a positive integer less than or equal to m. The resistance value of the i-th temperature-sensitive metal wire corresponding to the i-th group of currents obtained by real-time measurement of the i-th group of currents applied to N heat source metal wires 12 is... This represents the temperature change of the metal layer containing the temperature-sensitive metal wire 11 caused by the coupled thermal effect corresponding to the i-th group of currents; the m groups of currents are not the same. S3. Evaluate the interlayer coupling thermal effect of the metal layer containing the temperature-sensitive metal wire by taking the m temperature changes caused by the coupling thermal effect corresponding to the m sets of currents.
[0012] Ideally, all N currents in each current group should be identical.
[0013] Ideally, at least two of the N currents in each group should be different.
[0014] Preferably, the set ambient temperature is 0℃~50℃.
[0015] Preferably, the set duration is between 1 second and 600 seconds.
[0016] Preferably, in step S1, the test temperature is within the range of 25°C to 200°C.
[0017] Preferably, in step S1, a constant current is applied to the temperature-sensitive metal wire 11, in the range of 0.001mA to 0.1mA.
[0018] Preferably, in step S1, the resistance value of the temperature-sensitive metal wire is measured using the four-terminal method.
[0019] Preferably, in step S1, a constant current of 0.01mA is applied to the temperature-sensitive metal wire 11 at three test temperatures of 25℃, 75℃, and 125℃ respectively, and the temperature coefficient of resistance (TCR) of the temperature-sensitive metal wire 11 is calculated based on the relative change in resistance of the temperature-sensitive metal wire 11 at different test temperatures.
[0020] Preferably, in each group of currents, at least one of the heat source metal wires 12 applies a current that is not zero. The test structure for inter-metal coupling heat of the present invention includes a temperature-sensitive metal wire 11 and N heat source metal wires 12 formed in different metal layers. During the inter-metal coupling heat test, a constant current stress is first applied to the temperature-sensitive metal wire 11 under different temperature stresses, and the temperature coefficient of resistance (TCR) of the temperature-sensitive metal wire 11 is calculated. Different sets of current stresses are applied to the heat source metal wires 12, and the resistance value of the temperature-sensitive metal wire 11 is measured in real time. Then, based on the temperature coefficient of resistance (TCR) of the temperature-sensitive metal wire 11 and the resistance value of the temperature-sensitive metal wire measured in real time under different sets of current stresses applied to the heat source metal wires 12, the temperature change value (ΔT) of the metal layer where the temperature-sensitive metal wire is located due to the coupling heat effect generated by the heat source metal wires corresponding to each set of currents is calculated. This allows for rapid qualitative analysis of inter-metal coupling heat, determination of the thermal diffusion capability of the inter-metal medium, and simultaneous correction of the impact of coupling heat on interconnect reliability. It provides data support for the selection of inter-metal medium materials and provides technical support for data verification of subsequent simulation technology and the development of new manufacturing processes. Attached Figure Description
[0021] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0022] Figure 1 This is a schematic diagram of an embodiment of the test structure for interlayer coupling heat of the metal according to the present invention.
[0023] Explanation of the reference numerals in the figure: 11. Temperature-sensitive metal wire; 12. Heat source metal wire. Detailed Implementation
[0024] The technical solutions of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0025] Example 1: A test structure for interlayer coupling heat in metals, as shown below. Figure 1 As shown, the test structure is manufactured in the back end of the line (BEOL) process of semiconductor device manufacturing. It includes a temperature-sensitive metal line 11 and N heat source metal lines 12, where N is a positive integer. The temperature-sensitive metal wire 11 and the N heat source metal wires 12 are located in different metal layers and distributed in N+1 metal layers; The transverse wiring direction of one temperature-sensitive metal wire 11 and N heat source metal wires 12 is consistent; A temperature-sensitive metal wire 11 and N heat source metal wires 12 have a common overlapping area in their vertical projections; One end of each of the N heat source metal wires 12 is shorted to the same heat source contact pad (PAD1), and the other end is shorted to different heat source contact pads (PAD3, PAD5); One end of a temperature-sensitive metal wire 11 is shorted to the second temperature-sensitive contact pad PAD2, and the other end is shorted to the fourth temperature-sensitive contact pad PAD4.
[0026] Preferably, when N is greater than 1, the metal layer containing a temperature-sensitive metal wire 11 is located between the metal layers containing two adjacent heat source metal wires 12. Figure 1 In this case, N is 2.
[0027] Preferably, the heat source metal wire 12 is made of aluminum, copper, tungsten, tantalum, or manganese.
[0028] Preferably, the temperature-sensitive metal wire 11 is made of aluminum or copper, etc.
[0029] Example 2: A method for testing interlayer coupling heat using the test structure of Example 1, comprising the following steps: The interlayer coupling thermal testing method for the test structure described in claim 1 is characterized by comprising the following steps: S1. Apply a constant current to the temperature-sensitive metal wire 11 at different test temperatures, and calculate the temperature coefficient of resistance (TCR) of the temperature-sensitive metal wire 11 based on the relative change in resistance of the temperature-sensitive metal wire 11 at different temperatures. At a set ambient temperature, current is applied to each heat source metal wire 12 for a set duration, and the resistance value of the temperature-sensitive metal wire 11 is measured in real time; the current applied to each heat source metal wire 12 is changed, and the resistance values of m temperature-sensitive metal wires 11 corresponding to m sets of currents are measured in real time. Each set of currents consists of N currents applied to N heat source metal wires 12, where m is a positive integer. S2. Based on the temperature coefficient of resistance (TCR) of the temperature-sensitive metal wire 11 obtained in step S1 and the m resistance values of the temperature-sensitive metal wire 11 corresponding to the m sets of currents, calculate the m temperature changes in the metal layer where the temperature-sensitive metal wire is located due to the coupled thermal effect corresponding to the m sets of currents. , This is the real-time measured resistance value of the temperature-sensitive metal wire when no current is applied to the heat source metal wire 12 at the set ambient temperature; i is a positive integer less than or equal to m. The resistance value of the i-th temperature-sensitive metal wire corresponding to the i-th group of currents obtained by real-time measurement of the i-th group of currents applied to N heat source metal wires 12 is... This represents the temperature change of the metal layer containing the temperature-sensitive metal wire 11 caused by the coupled thermal effect corresponding to the i-th group of currents; the m groups of currents are not the same. S3. Evaluate the interlayer coupling thermal effect of the metal layer containing the temperature-sensitive metal wire by taking the m temperature changes caused by the coupling thermal effect corresponding to the m sets of currents.
[0030] Ideally, all N currents in each current group should be identical.
[0031] Ideally, at least two of the N currents in each group should be different.
[0032] Preferably, the set ambient temperature is 0℃~50℃.
[0033] Preferably, the set duration is between 1 second and 600 seconds.
[0034] Preferably, in step S1, the test temperature is within the range of 25°C to 200°C.
[0035] Preferably, in step S1, a constant current is applied to the temperature-sensitive metal wire 11, in the range of 0.001mA to 0.1mA.
[0036] Preferably, in step S1, the resistance value of the temperature-sensitive metal wire is measured using the four-terminal method.
[0037] Preferably, in step S1, a constant current of 0.01mA is applied to the temperature-sensitive metal wire 11 at three test temperatures of 25℃, 75℃, and 125℃ respectively, and the temperature coefficient of resistance (TCR) of the temperature-sensitive metal wire 11 is calculated based on the relative change in resistance of the temperature-sensitive metal wire 11 at different test temperatures.
[0038] Preferably, in each group of currents, at least one of the heat source metal wires 12 applies a current that is not zero.
[0039] The test method for interlayer coupling heat in Example 2 includes a test structure comprising a temperature-sensitive metal wire 11 and N heat source metal wires 12 formed in different metal layers. During the test, a constant current stress is first applied to the temperature-sensitive metal wire 11 under different temperature stresses, and the temperature coefficient of resistance (TCR) of the temperature-sensitive metal wire 11 is calculated. Different sets of current stresses are applied to the heat source metal wires 12, and the resistance value of the temperature-sensitive metal wire 11 is measured in real time. Then, based on the temperature coefficient of resistance (TCR) of the temperature-sensitive metal wire 11 and the resistance value of the temperature-sensitive metal wire measured in real time when different sets of current stresses are applied to the heat source metal wires 12, the temperature change value (ΔT) of the metal layer where the temperature-sensitive metal wire is located due to the coupling heat effect generated by the heat source metal wires corresponding to each set of currents is calculated.
[0040] The test method for intermetallic coupling heat in Example 2 can quickly and qualitatively analyze the intermetallic coupling heat, determine the thermal diffusion capability of the intermetallic medium, and simultaneously correct the degree of influence of coupling heat on interconnect reliability. It provides data support for the selection of intermetallic medium materials and provides technical support for data verification of downstream simulation technology and the development of new process technologies.
[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A test structure for interlayer coupling heat in metals, characterized in that, It includes a temperature-sensitive metal wire (11) and N heat source metal wires (12), where N is a positive integer; The temperature-sensitive metal wire (11) and the N heat source metal wires (12) are located in different metal layers and distributed in N+1 metal layers; The transverse wiring direction of one temperature-sensitive metal wire (11) and N heat source metal wires (12) is consistent; A temperature-sensitive metal wire (11) and N heat source metal wires (12) have a common overlapping area in the vertical projection; One end of each of the N heat source metal wires (12) is shorted to the same heat source contact pad, and the other end is shorted to different heat source contact pads respectively; One end of a temperature-sensitive metal wire (11) is shorted to the second temperature-sensitive contact pad, and the other end is shorted to the fourth temperature-sensitive contact pad.
2. The test structure for interlayer coupling heat of metals according to claim 1, characterized in that, The test structure for evaluating inter-metal coupling heat is fabricated in the back-end process of semiconductor device manufacturing.
3. The test structure for interlayer coupling heat of metals according to claim 1, characterized in that, When N is greater than 1, the metal layer containing a temperature-sensitive metal wire (11) is located between the metal layers containing two adjacent heat source metal wires (12).
4. The test structure for interlayer coupling heat of metals according to claim 1, characterized in that, N is 2.
5. The test structure for interlayer coupling heat of metals according to claim 1, characterized in that, The heat source metal wire (12) is made of aluminum, copper, tungsten, tantalum or manganese.
6. The test structure for interlayer coupling heat of metals according to claim 1, characterized in that, The temperature-sensitive metal wire (11) is made of aluminum or copper.
7. A method for testing interlayer coupling thermal properties of metals using the test structure described in claim 1, characterized in that, Includes the following steps: S1. Apply a constant current to the temperature-sensitive metal wire (11) at different test temperatures, and calculate the temperature coefficient of resistance (TCR) of the temperature-sensitive metal wire (11) based on the relative change of resistance of the temperature-sensitive metal wire (11) at different temperatures. At a set ambient temperature, current is applied to each heat source metal wire (12) for a set duration, and the resistance value of the temperature-sensitive metal wire (11) is measured in real time; the current applied to each heat source metal wire (12) is changed, and the resistance values of m temperature-sensitive metal wires (11) corresponding to m sets of currents are measured in real time. Each set of currents consists of N currents applied to N heat source metal wires (12), where m is a positive integer. S2. Based on the temperature coefficient of resistance (TCR) of the temperature-sensitive metal wire (11) obtained in step S1 and the resistance values of the m temperature-sensitive metal wire (11) corresponding to the m sets of currents, calculate the m temperature changes in the metal layer where the temperature-sensitive metal wire is located caused by the coupling thermal effect corresponding to the m sets of currents. , The resistance value of the temperature-sensitive metal wire (12) is measured in real time when no current is applied to the heat source metal wire (12) at the set ambient temperature; i is a positive integer less than or equal to m. The resistance value of the i-th temperature-sensitive metal wire corresponding to the i-th group of currents obtained by real-time measurement of the i-th group of currents applied to N heat source metal wires (12) is given. The temperature change of the metal layer where the temperature-sensitive metal wire (11) is located is caused by the coupling thermal effect corresponding to the i-th group of currents; the m groups of currents are different; S3. Evaluate the interlayer coupling thermal effect of the metal layer containing the temperature-sensitive metal wire by taking the m temperature changes caused by the coupling thermal effect corresponding to the m sets of currents.
8. The interlayer coupling thermal testing method for metals according to claim 7, characterized in that, All N currents in each current group are identical.
9. The interlayer coupling thermal testing method for metals according to claim 7, characterized in that, In each group of currents, at least two of the N currents are different.
10. The interlayer coupling thermal testing method for metals according to claim 7, characterized in that, The set ambient temperature is 0℃~50℃.
11. The interlayer coupling thermal testing method for metals according to claim 7, characterized in that, The set duration is from 1 second to 600 seconds.
12. The interlayer coupling thermal testing method for metals according to claim 7, characterized in that, In step S1, the test temperature is within the range of 25°C to 200°C.
13. The interlayer coupling thermal testing method for metals according to claim 7, characterized in that, In step S1, a constant current is applied to the temperature-sensitive metal wire (11) in the range of 0.001mA to 0.1mA.
14. The interlayer coupling thermal testing method for metals according to claim 7, characterized in that, In step S1, the resistance value of the temperature-sensitive metal wire is measured using the four-terminal method.
15. The interlayer coupling thermal testing method for metals according to claim 7, characterized in that, In step S1, a constant current of 0.01mA is applied to the temperature-sensitive metal wire (11) at three test temperatures of 25℃, 75℃ and 125℃ respectively. Based on the relative change of the resistance of the temperature-sensitive metal wire (11) at different test temperatures, the temperature coefficient of resistance (TCR) of the temperature-sensitive metal wire (11) is calculated.
16. The interlayer coupling thermal testing method for metals according to claim 7, characterized in that, In each group of currents, at least one heat source metal wire (12) applies a current that is not zero.