Al wiring material

Abstract

Provided is an Al wiring material with which the joined reliability of a joint under high-temperature environments during the operation of a semiconductor device can be sufficiently obtained. An Al wiring material contains at least one among Pd and Pt, with the balance comprising Al, wherein: when the content of Pd is x1a [mass ppm] and the content of Pt is x1b [mass ppm], 3≤x1a≤90 or 10≤x1b≤250 is satisfied and 3≤(x1a＋x1b)≤300 is satisfied; and the average crystal grain diameter in a cross section perpendicular to the longitudinal direction of the Al wiring material is 3-35 μm.

Description

[Technical Field]

[0001] The present invention relates to an Al wiring material, and further to a semiconductor device including the Al wiring material. [Background technology]

[0002] As a wire-shaped material used for electrical and mechanical connections in industrial equipment and electronic components, the use of aluminum (Al) is increasing due to its lighter weight and lower cost than the conventional copper (Cu) in line with the demand for computerization in automobiles. The Al wire (round) and Al strip (flat and oval) used in industrial equipment such as transport equipment and robots require mechanical properties such as breaking strength and elongation, as well as electrical conductivity and thermal conductivity, depending on the intended use.

[0003] In semiconductor devices, electrodes formed on a semiconductor chip are connected to electrodes on a lead frame or a substrate by bonding wires or bonding ribbons. In power semiconductor devices, Al is mainly used as the material. For example, Patent Document 1 shows an example in which a 300 μmφ Al bonding wire is used in a power semiconductor module. In power semiconductor devices using Al bonding wires or Al bonding ribbons, wedge bonding is used as the bonding method for both the first connection with the electrodes on the semiconductor chip and the second connection with the electrodes on the lead frame or a substrate.

[0004] The above-mentioned Al wire, Al strip, Al bonding wire, Al bonding ribbon, etc. are hereinafter collectively referred to as Al wiring material.

[0005] Power semiconductor devices using Al wiring materials are often used in electronic devices such as automotive control devices, air conditioners, and solar power generation systems. In these semiconductor devices, the joints between the wiring materials and connected components are exposed to high temperatures during device operation. Rapid on / off switching of high voltage creates a harsh environment where temperatures repeatedly rise and fall. When materials made solely of high-purity Al are used as wiring materials, they tend to soften in the temperature environment during device operation, making them difficult to use in high-temperature environments.

[0006] Al wiring materials made of Al with specific elements added have been proposed. For example, Patent Document 2 discloses an Al bonding wire with improved mechanical strength achieved by adding 0.05 to 1 weight percent scandium (Sc) to Al to cause precipitation hardening. Patent Document 3 discloses that an Al wiring material containing 800 weight ppm or less of one or more of nickel (Ni), silicon (Si), and phosphorus (P) in total exhibits good bonding strength and weather resistance. Patent Document 4 discloses an Al bonding wire containing 0.01 to 0.2 weight percent iron (Fe) and 1 to 20 weight ppm Si, with a solid solution amount of Fe of 0.01 to 0.06 weight percent, a precipitation amount of Fe of 7 times or less the solid solution amount, and an average crystal grain size of 6 to 12 μm, and describes that the wire exhibits good bonding reliability. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-314038 [Patent Document 2] Special Publication No. 2016-511529 [Patent Document 3] Japanese Patent Application Laid-Open No. 2016-152316 [Patent Document 4] Japanese Patent Application Laid-Open No. 2014-129578 Summary of the Invention [Problem to be solved by the invention]

[0008] As industrial equipment and electronic components become more functional and their range of applications expands, the demands placed on aluminum wiring materials are becoming more stringent. Aluminum wiring materials used in electronic components such as semiconductor devices face stringent requirements, such as the ability to bond multiple thin-diameter aluminum wiring materials to the same electrode in order to simultaneously achieve miniaturization and high output. Meanwhile, thick aluminum wiring materials are used for high-output power devices or as a lightweight alternative to copper wiring materials. When bonding thick aluminum wiring materials, deformation and bonding variations often become problems. Furthermore, aluminum, nickel-palladium (Ni-Pd), copper, and other materials are commonly used for electrodes on semiconductor chips, and as the electrode film thickness increases, it is increasingly difficult to ensure the strength of the bonding interface. To accommodate these diverse aluminum wiring diameters, electrode materials, and film thicknesses, improvements in bonding performance are required.

[0009] Furthermore, due to the expanding use of power devices for automobiles, there is a demand for improved initial bondability and bond reliability of Al wiring materials in high-temperature environments. In semiconductor devices, Al wiring materials are bonded to electrodes on semiconductor chips, and it is important to increase the bond strength of the bond between the Al wiring material and the electrodes. Bond strength (hereinafter referred to as "shear strength") measured by a shear test in which the bond is shear-fractured is generally used to evaluate the bond strength of the bond between an Al wiring material and an electrode. Although high shear strength is desirable, it has been confirmed that even with high shear strength, peeling failure may occur in high-temperature environments, resulting in poor bond reliability. Shear strength measured by shear-fracturing the bond is effective as an index of apparent bond strength, but it is difficult to accurately assess the state of the bond interface using shear strength for Al wiring material joints with relatively large bond areas.

[0010] As described above, simply increasing the shear strength, which is the standard standard for the bondability of Al wiring materials, can result in poor peeling under high-temperature conditions, resulting in poor bonding reliability. For example, it is known that adding Ni to Al wiring materials can produce bonds with high shear strength (Patent Document 3), but even with this technology, poor peeling can occur under high-temperature conditions, resulting in poor bonding reliability.

[0011] The inventors investigated the relationship between bonding behavior and peel failure and found that one of the causes of peel failure is the presence of insufficient bonding at the bonded interface. Specifically, in cases where peel failure occurs, observation of the electrode-side fracture surface after a shear test revealed a high frequency of unbonded regions (hereinafter also referred to as "voids"), where metal bonding is not achieved at a portion of the bond. Increasing voids in the bond not only reduces productivity but also induces defects such as cracks originating from the unbonded regions due to temperature changes during semiconductor device operation, and further delamination of the bond. While increasing the load and ultrasonic output during bonding has been considered to reduce the occurrence of voids during bonding, this method has the problem of causing damage to the semiconductor chip, such as cracks (hereinafter referred to as "chip damage").

[0012] Furthermore, it is becoming increasingly difficult to achieve or improve the long-term reliability of joints in high-temperature environments, which is required for high-temperature power devices such as SiC. One method for evaluating the reliability of joints in high-temperature environments is a power cycle test. This test involves repeated rapid heating and cooling by repeatedly turning the voltage on and off. Repeated rapid heating and cooling can cause problems, such as a decrease in the joint strength of Al wiring materials and the occurrence of defects such as cracks and delamination near the joint interface. For example, with regard to durability in power cycle tests, under harsh conditions of more than 10,000 cycles, defects such as cracks and delamination can occur in the joints of Al wiring materials, hindering the practical application of power devices.

[0013] As described above, with regard to the bondability of Al wiring materials, in addition to increasing the shear strength, reducing the amount of hole formed during bonding and improving the bonding reliability of the joint in high-temperature environments is beneficial for improving the functionality, quality, reliability, etc. of automotive power devices.

[0014] An object of the present invention is to provide an Al wiring material that can provide sufficient bonding reliability at the bonding portion in the high-temperature environment during operation of a semiconductor device. [Means for solving the problem]

[0015] As a result of extensive research into the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by using an Al wiring material having the following composition. Based on this finding, further research has led to the completion of the present invention. That is, the present invention includes the following. [1] When one or more of Pd and Pt are contained, and the Pd and Pt contents are x1a [ppm by mass] and x1b [ppm by mass], respectively, 3≦x1a≦90 or 10≦x1b≦250 is satisfied, and 3≦(x1a+x1b)≦300 is satisfied, The balance is an Al wiring material containing Al, An Al wiring material having an average crystal grain size of 3 to 35 μm in a cross section perpendicular to the longitudinal direction of the Al wiring material. [2] In a cross section perpendicular to the longitudinal direction of the Al wiring material, the crystal orientation has an angle difference of 15° or less with respect to the longitudinal direction of the Al wiring material. <111> The Al wiring material according to [1], wherein the orientation ratio is 0.5% or more and 35% or less. [3] The Al wiring material according to [1] or [2], which has a tensile strength of 25 MPa or more and 95 MPa or less. [4] When one or more of Mg, Mn, and Cu are further contained and the total content is x2 [ppm by mass], The aluminum wiring material according to any one of [1] to [3], which satisfies 200≦x2≦6000. [5] When one or more of Fe, Si, and Ni are further contained and the total content is x3 [ppm by weight], The aluminum wiring material according to any one of [1] to [4], which satisfies 10≦x3≦2000. [6] The Al wiring material according to any one of [1] to [5], wherein the Al content is 98 mass % or more. [7] The Al wiring material according to any one of [1] to [6], wherein the remainder consists of Al and inevitable impurities. [8] A semiconductor device comprising the Al wiring material according to any one of [1] to [7]. [Effects of the Invention]

[0016] According to the present invention, there is provided an Al wiring material that can provide sufficient bonding reliability at the bonding portion even in the high temperature environment during operation of a semiconductor device. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described in detail below with reference to preferred embodiments thereof. However, the present invention is not limited to the following embodiments and examples, and can be implemented with any modifications within the scope of the claims of the present invention and their equivalents.

[0018] [Al wiring material] The Al wiring material of the present invention contains one or more of Pd and Pt, and when the contents of Pd and Pt are x1a [ppm by mass] and x1b [ppm by mass], respectively, they satisfy 3≦x1a≦90 or 10≦x1b≦250 and also satisfy 3≦(x1a+x1b)≦300, with the remainder being Al, and is characterized in that the average crystal grain size in a cross section perpendicular to the longitudinal direction of the Al wiring material is 3 to 35 μm.

[0019] As mentioned above, Al wiring materials are required to simultaneously achieve both improved bondability immediately after bonding (hereinafter referred to as "initial bonding") and reduced chip damage, and furthermore, after bonding, to improve the bonding reliability of the bond in the high-temperature environment during operation of the semiconductor device (hereinafter also referred to as "high-temperature reliability of the bond"). With regard to bondability, it is important to not only increase shear strength but also to reduce unbonded areas ("voids") in the bond.

[0020] The Al wiring material of the present invention contains a predetermined amount of one or more of Pd and Pt (hereinafter also referred to as "first group elements") and has an average crystal grain size within a specific range. When the Al wiring material is bonded to an electrode by applying load and ultrasonic waves, diffusion at the bonding interface is promoted, thereby suppressing the occurrence of unbonded areas at the bonding interface and achieving a good bond throughout the entire bonding interface. Reducing the unbonded areas increases the ratio of the area of ​​the bonding interface that has a metallurgical bond and directly contributes to the bonding (hereinafter referred to as the "effective bonding area ratio" or "EBR"). The effective bonding area used to estimate the effective bonding area ratio (EBR) can be easily calculated as the area of ​​the bonding interface excluding the unbonded areas. The inventors have discovered that increasing the EBR significantly improves the high-temperature reliability of the bond.

[0021] In other words, by setting the content and grain size of the first group elements in the Al wiring material within the ranges of the present invention, a significant effect of improving EBR can be obtained. Improving EBR improves the bondability at the initial bonding stage, which in turn increases the high-temperature reliability of the bonded portion.

[0022] The effect of containing a predetermined amount of a first group element is thought to be that it suppresses the growth of an Al oxide film on the surface of the Al wiring material, and even if an Al oxide film is formed, it is easier to destroy the Al oxide film by ultrasonic vibration during bonding, thereby promoting the diffusion of Al from the Al wiring material to the electrode side. Furthermore, the effect of setting the crystal grain size of the Al wiring material within a specific range is thought to be that it reduces the crystal grain boundaries that act as resistance to deformation during bonding, increasing the efficiency of ultrasonic transmission to the bonding interface, thereby promoting the destruction of the oxide films on the Al wiring material and the electrode. In the Al wiring material of the present invention, the effect of containing a predetermined amount of a first group element and the effect of setting the crystal grain size within a specific range work synergistically, thereby significantly improving the high-temperature reliability of the joint.

[0023] By combining the inclusion of a first group element with the control of the average crystal grain size in a cross section perpendicular to the longitudinal direction of the Al wiring material (hereinafter referred to as the "C cross section"), a high synergistic effect can be achieved, which facilitates increasing the EBR and improving the initial bondability. It has been confirmed that even with Al wiring materials containing a first group element, if the average crystal grain size in the C cross section is smaller than the range specified in this application, the oxide film is not sufficiently destroyed during bonding, and the effect of improving the EBR is small. Even with Al wiring materials with large crystal grain size and low tensile strength, if the material is high-purity Al or conventional Al wiring materials containing Ni, the area of ​​the bonding interface can be increased, but unbonded areas remain, and the effect of improving the EBR is small.

[0024] To maximize the effects of the first group elements, it is important to control the average crystal grain size in the C-section of the Al wiring material. When bonding Al wiring materials, the application of load and ultrasonic vibration to the Al wiring material using a capillary significantly deforms the circular C-section, changing its shape to an ellipse, trapezoid, triangle, or other shape after bonding. This shape change promotes bonding to the electrode. The inventors have found that the average crystal grain size in the C-section is related to the shape change in the C-section and EBR. In other words, controlling the average crystal grain size in the C-section in combination with the inclusion of the first group elements is more important for achieving the effects of the present invention than controlling the structure and crystal grain size in the cross section parallel to the longitudinal direction of the Al wiring material.

[0025] As described above, by simultaneously controlling the content of the first group elements and the crystal grain size in the C cross section of Al wiring materials, a significant effect of increasing EBR can be achieved. This allows the EBR to be increased even when bonding Al wiring materials at room temperature, making it possible to use resin substrates that are sensitive to heat. Furthermore, the EBR can be increased even when the load and ultrasonic output applied during bonding are reduced, resulting in advantages such as increased yield and productivity even when using semiconductor chips that are prone to chip damage, such as semiconductor chips with thin electrode films.

[0026] The EBR at the bonded portion with an electrode on a semiconductor chip is calculated as the ratio (M2 / M1) of the area where a metallic bond is achieved to the area M1 of the bonded interface. For example, the EBR at the bonded portion between an Al wiring material and an electrode on a semiconductor chip can be calculated using the following procedure. First, a shear test is conducted on the bonded portion, and the broken bonded electrode is observed using an optical microscope or SEM. Next, image analysis is used to determine the area M1 of the bonded interface and the area M3 of the unbonded region where the electrode is deformed during bonding but no metallic bond is achieved, and the area M2 (= M1 - M3) where a metallic bond is achieved is calculated. The EBR value can be calculated as the ratio (M2 / M1) of M2 to M1, specifically using the formula EBR = M2 / M1 = (M1 - M3) / M1.

[0027] The Al wiring material of the present invention contains one or more of Pd and Pt as first group elements, and when the contents of Pd and Pt are x1a [ppm by mass] and x1b [ppm by mass], respectively, they satisfy 3≦x1a≦90 or 10≦x1b≦250 and also satisfy 3≦(x1a+x1b)≦300. Preferred ranges for x1a and x1b are shown below, but as long as their total value, i.e., (x1a+x1b), is within the above-mentioned range, only the preferred range for x1a may be satisfied, only the preferred range for x1b may be satisfied, or both the preferred ranges for x1a and x1b may be satisfied.

[0028] From the viewpoint of increasing EBR and thus improving the high-temperature reliability of the joint, the Pd content in the Al wiring material, i.e., x1a, is 3 ppm by mass or more. If x1a is less than 3 ppm by mass, the effect of increasing EBR and thus the effect of improving the high-temperature reliability of the joint are insufficient. x1a is preferably 4 ppm by mass or more, 5 ppm by mass or more, or 6 ppm by mass or more, and more preferably more than 6 ppm by mass, 8 ppm by mass or more, 10 ppm by mass or more, 15 ppm by mass or more, or 20 ppm by mass or more. If x1a is more than 6 ppm by mass, the effect of further increasing EBR can be obtained, provided that the value of (x1a + x1b) in relation to x1b is within the range of the present invention.

[0029] From the viewpoint of uniformly deforming the Al wiring material during bonding to improve the high-temperature reliability of the bonded portion, x1a is 90 mass ppm or less. When x1a exceeds 90 mass ppm, the deformation of the Al wiring material becomes non-uniform during bonding, and the EBR tends to decrease. x1a is preferably 85 mass ppm or less, 80 mass ppm or less, 75 mass ppm or less, or 70 mass ppm or less, more preferably less than 70 mass ppm, 68 mass ppm or less, 66 mass ppm or less, or 65 mass ppm or less. When x1a is less than 70 mass ppm on the condition that the value of (x1a + x1b) is within the scope of the present invention in relation to x1b, the effect of further increasing the EBR can be obtained.

[0030] Therefore, in a preferred embodiment, the content of Pd in the Al wiring material, that is, x1a, satisfies 3 ≦ x1a ≦ 90, and more preferably satisfies 6 < x1a < 70.

[0031] From the viewpoint of increasing the EBR and thus improving the high-temperature reliability of the bonded portion, the content of Pt in the Al wiring material, that is, x1b, is 10 mass ppm or more. When x1b is less than 10 mass ppm, the effect of increasing the EBR and thus the effect of improving the high-temperature reliability of the bonded portion are not sufficient. x1b is preferably 12 mass ppm or more, 14 mass ppm or more, 16 mass ppm or more, 18 mass ppm or more, or 20 mass ppm or more, more preferably more than 20 mass ppm, 25 mass ppm or more, 30 mass ppm or more, 35 mass ppm or more, or 40 mass ppm or more. When x1b is more than 20 mass ppm on the condition that the value of (x1a + x1b) is within the scope of the present invention in relation to x1a, the effect of further increasing the EBR can be obtained.

[0032] From the perspective of uniformly deforming the Al wiring material during bonding to improve the high-temperature reliability of the bonding part, x1b is 250 mass ppm or less. When x1b exceeds 250 mass ppm, the deformation of the Al wiring material becomes non-uniform during bonding, and the EBR tends to decrease. x1b is preferably 240 mass ppm or less, 230 mass ppm or less, 220 mass ppm or less, 210 mass ppm or less, or 200 mass ppm or less, more preferably less than 200 mass ppm, 190 mass ppm or less, 180 mass ppm or less, 160 mass ppm or less, or 150 mass ppm or less. On the condition that the value of (x1a + x1b) is within the scope of the present invention in relation to x1a, when x1b is less than 200 mass ppm, the effect of further increasing the EBR can be obtained.

[0033] Therefore, in a preferred embodiment, the content of Pt in the Al wiring material, that is, x1b, satisfies 10 ≦ x1b ≦ 250, and more preferably satisfies 20 < x1b < 200.

[0034] [[ID=...]] From the perspective of increasing the EBR and thus improving the high-temperature reliability of the bonding part, the total content of Pd and Pt in the Al wiring material, that is, (x1a + x1b), is 3 mass ppm or more. When (x1a + x1b) is less than 3 mass ppm, the effect of increasing the EBR and thus the effect of improving the high-temperature reliability of the bonding part are not sufficient. (x1a + x1b) is preferably 5 mass ppm or more or 6 mass ppm or more, more preferably more than 6 mass ppm, 8 mass ppm or more, 10 mass ppm or more, 15 mass ppm or more, or 20 mass ppm or more. The upper limit of (x1a + x1b) is 300 mass ppm or less on the condition that x1a and x1b satisfy the above range, preferably 290 mass ppm or less, 280 mass ppm or less, or 270 mass ppm or less, more preferably less than 270 mass ppm, 260 mass ppm or less, or 250 mass ppm or less.

[0035] It has been confirmed that Pd is more effective than Pt in promoting the destruction and diffusion of oxide films at the bonding interface. As a result, it has been confirmed that the preferred range of the Pd content x1a for increasing EBR is lower than the preferred range of the Pt content x1b. Furthermore, it is presumed that if the Pd content x1a exceeds 90 ppm by mass, variations in the oxide film and structure on the surface of the Al wiring material occur, making it more likely that non-uniform deformation will occur, resulting in a decrease in EBR.

[0036] In the Al wiring material of the present invention, the average crystal grain size in the C cross section of the Al wiring material is 3 to 35 μm. If the average crystal grain size is less than 3 μm, the unbonded region tends to increase during bonding, and the effect of increasing EBR is small. The average crystal grain size in the C cross section is preferably 3.5 μm or more, 4 μm or more, 4.5 μm or more, 5 μm or more, 6 μm or more, or 7 μm or more, more preferably 8 μm or more, 8.5 μm or more, or 9 μm or more. On the other hand, it has been confirmed that if the average crystal grain size in the C cross section exceeds 35 μm, abnormal deformation of coarse crystal grains, etc., causes the bond shape and area to become unstable, thereby reducing EBR. The upper limit of the average crystal grain size is preferably 34 μm or less, 33 μm or less, 32 μm or less, or 31 μm or less, more preferably 30 μm or less, 28 μm or less, 26 μm or less, or 25 μm or less. When the average crystal grain size in the C cross section is in the range of 8 to 30 μm, it becomes easy to manufacture the Al wiring material stably during mass production.

[0037] Therefore, in a preferred embodiment, the average crystal grain size in the C cross section of the Al wiring material is 3 to 35 μm, and more preferably 8 to 30 μm.

[0038] In manufacturing Al wiring material, by performing thermal refining treatments during the wire drawing process and near the final wire diameter, the average crystal grain size in the C cross section of the Al wiring material tends to be more easily adjusted to the above-mentioned preferred range.

[0039] In the present invention, the average crystal grain size in the C cross section of the Al wiring material was obtained by determining the circle-equivalent diameter of each crystal grain using electron backscattered diffraction (EBSD) and arithmetically averaging the diameters. In the present invention, the average crystal grain size in the C cross section was determined as the arithmetic mean of the values ​​obtained by measuring C cross sections at five or more locations. When selecting the measurement surface (C cross section), it is preferable to ensure the objectivity of the measurement data by, for example, obtaining five or more measurement samples from the Al wiring material to be measured at intervals of 1 m or more in the longitudinal direction of the Al wiring material.

[0040] - <111> Crystal orientation ratio - In the Al wiring material of the present invention, in a cross section (C cross section) perpendicular to the longitudinal direction of the Al wiring material, <111> By setting the orientation ratio of the crystal orientation within a specific range, the EBR can be further increased.

[0041] Specifically, as a result of measuring the crystal orientation of the C-section of the Al wiring material, the crystal orientation in the longitudinal direction of the Al wiring material has an angle difference of 15° or less with respect to the longitudinal direction of the Al wiring material. <111> The orientation ratio of the crystal orientation is preferably 0.5 to 35%. <111> By controlling the structure to keep the orientation ratio of the crystal orientation low, the EBR can be further increased, and a particularly significant effect of improving the EBR can be obtained even with large-diameter Al wiring materials.

[0042] <111> The orientation ratio of crystal orientations can be measured using the EBSD method. The equipment used for the EBSD method consists of a scanning electron microscope and a detector attached to it. EBSD is a technique that determines the crystal orientation at each measurement point by projecting the diffraction pattern of the backscattered electrons generated when an electron beam is irradiated onto a sample onto a detector and analyzing this diffraction pattern. Dedicated software (such as OIM analysis by TSL Solutions, Inc.) can be used to analyze data obtained by the EBSD method. By using the C-section of the Al wiring material as the inspection surface and the analysis software provided with the equipment, the orientation ratio of a specific crystal orientation can be calculated.

[0043] In the present invention, <111> The orientation ratio of the crystal orientation is calculated by taking the measurement area as the population. <111> The orientation ratio is defined as the area ratio of the crystal orientation. In calculating the orientation ratio, the area of ​​only the crystal orientations that could be identified based on a certain reliability within the measurement area was calculated as the population. <111> The area ratio of the crystal orientation is <111> In the process of calculating the orientation ratio, areas where the crystal orientation could not be measured, or areas where the orientation analysis was unreliable even if it could be measured, were excluded from the calculation.

[0044] In the present invention, in the C section <111> The orientation ratio of the crystal orientation was the arithmetic mean value of the orientation ratios obtained by measuring five or more C-sections. When selecting the measurement surface (C-section), as mentioned above, it is preferable to ensure the objectivity of the measurement data by, for example, obtaining measurement samples from the Al wiring material to be measured at intervals of 1 m or more in the longitudinal direction of the Al wiring material.

[0045] As the wire diameter of the Al wiring material increases, the load and ultrasonic waves applied during bonding become less likely to be transmitted to the center of the bonding interface, and the area of ​​the unbonded region (hollow area) tends to increase. <111> By reducing the orientation ratio of the crystal orientation, the ultrasonic vibration transmission efficiency can be improved even for large-diameter Al wiring materials, and EBR can be increased. The effect of this crystal orientation can be enjoyed more when the wire diameter is 250 μm or more, and even more when the wire diameter is 300 μm or more or 350 μm or more.

[0046] In the C-section of the Al wiring material, the angle difference with respect to the longitudinal direction of the Al wiring material is 15° or less. <111> The orientation ratio of the crystal orientation is preferably 0.5% or more and 35% or less. <111> If the orientation ratio of the crystal orientation exceeds 35%, the effect of increasing EBR tends to decrease when the diameter of the Al wiring material is large. <111> The orientation ratio of the crystal orientation is preferably less than 35%, 34% or less, 32% or less, or 30% or less, and more preferably less than 30%, 28% or less, 26% or less, 24% or less, 22% or less, or 20% or less. <111> It is difficult to stably control the orientation ratio of the crystal orientation to less than 0.5%. <111> The lower limit of the orientation ratio of the crystal orientation is preferably 0.6% or more, 0.8% or more, 1% or more, 1.5% or more, 2% or more, or 2.5% or more, more preferably 3% or more, 3.5% or more, or 4% or more. <111> When the orientation ratio of the crystal orientation is 3% or more and less than 30%, the effect of increasing EBR can be further improved.

[0047] Therefore, in a preferred embodiment, the angle difference with respect to the longitudinal direction of the Al wiring material in the C cross section of the Al wiring material is 15° or less. <111> The orientation ratio of the crystal orientation is preferably 0.5% or more and 35% or less, and more preferably 3% or more and less than 30%.

[0048] -Tensile strength- The Al wiring material of the present invention preferably has a tensile strength in the range of 25 MPa to 95 MPa. In the Al wiring material of the present invention, which contains a predetermined amount of a first group element and has an average crystal grain size in a specific range in a C cross section, the high-temperature reliability of the joint can be further improved by further adjusting the tensile strength to the above-mentioned preferred range.

[0049] High-temperature reliability can be evaluated by examining changes in the bonding strength or electrical properties of the Al wiring material after a power cycle test. By using the Al wiring material of the present invention, which contains a predetermined amount of a first group element and has an average crystal grain size in a specific range in cross section C, the occurrence of unbonded regions (voids) during bonding can be reduced, thereby improving the EBR at the initial bonding stage. Furthermore, it is believed that a tensile strength within the above range can suppress the propagation of cracks near the bonded portion of the Al wiring material, thereby further improving the high-temperature reliability of the bonded portion. That is, by containing a predetermined amount of a first group element and having an average crystal grain size in a specific range in cross section C, the occurrence of unbonded regions during bonding can be reduced. Furthermore, a tensile strength within the above range promotes deformation of the Al wiring material or destruction of the oxide film, resulting in a good metal bond with the electrode at the bonding interface, which is thought to suppress crack propagation during a power cycle test.

[0050] In the Al wiring material of the present invention, the tensile strength is preferably in the range of 25 MPa or more and 95 MPa or less. If the tensile strength exceeds 95 MPa, the Al wiring material is hard, and the effect of suppressing crack propagation in a power cycle test is not sufficiently obtained. The tensile strength of the Al wiring material is preferably less than 95 MPa, 94 MPa or less, 92 MPa or less, 90 MPa or less, 88 MPa or less, or 86 MPa or less, more preferably 85 MPa or less, 84 MPa or less, 82 MPa or less, or 80 MPa or less. On the other hand, if the tensile strength is less than 25 MPa, the Al wiring material is soft, and the wire diameter tends to become thinner during production of the Al wiring material, which tends to reduce the production yield. The tensile strength of the Al wiring material is preferably 26 MPa or more or 28 MPa or more, more preferably 30 MPa or more, 32 MPa or more, 34 MPa or more, 36 MPa or more, 38 MPa or more, or 40 MPa or more. If the tensile strength of the Al wiring material is 30 MPa or more and 85 MPa or less, the effect of further increasing EBR is obtained, which is beneficial.

[0051] Therefore, in a preferred embodiment, the tensile strength of the Al wiring material is preferably 25 MPa or more and 95 MPa or less, and more preferably 30 MPa or more and 85 MPa or less.

[0052] -Mg, Mn, Cu (Group 2 elements)- The Al wiring material of the present invention may further contain one or more of Mg, Mn, and Cu.

[0053] The Al wiring material of the present invention, which contains a predetermined amount of a first group element and has an average crystal grain size in a specific range in cross section, can further improve the high-temperature reliability of the joint by further containing one or more of Mg, Mn, and Cu (also referred to as "second group elements"). For example, by further containing a second group element, the Al wiring material of the present invention can increase the number of cycles until failure occurs by 1.5 times or more in a power cycle test.

[0054] As the number of cycles in a power cycle test increases, the same effect as an increase in heating time occurs. This causes recovery and recrystallization to progress within the Al wiring material, resulting in changes in the structure and making cracks more likely to develop. In contrast, the inclusion of a predetermined amount of a second group element can slow the progression of recovery and recrystallization. This, combined with the EBR improvement effect achieved by the inclusion of a first group element and controlling the crystal grain size, is thought to increase the number of cycles required for failure in a power cycle test. In this regard, it has been confirmed that the addition of a second group element alone is not effective in improving the high-temperature reliability of the joint. In the Al wiring material of the present invention, which contains a predetermined amount of a first group element and has an average crystal grain size in a C-section within a specific range, the addition of a predetermined amount of a second group element achieves a synergistic effect of further improving the high-temperature reliability of the joint.

[0055] In the Al wiring material of the present invention, when the total content of the second group elements is x2 [ppm by mass], it is preferable that x2 satisfies the relationship 200≦x2≦6000. If the total content of the second group elements, i.e., x2, is less than 200 ppm by mass, the effect of further improving the high-temperature reliability of the joint cannot be sufficiently obtained. x2 is preferably 220 ppm by mass or more, 240 ppm by mass or more, 250 ppm by mass or more, 260 ppm by mass or more, or 280 ppm by mass or more, and more preferably 300 ppm by mass or more, 320 ppm by mass or more, 340 ppm by mass or more, 360 ppm by mass or more, 380 ppm by mass or more, or 400 ppm by mass or more. On the other hand, if x2 exceeds 6000 ppm by mass, chip damage tends to occur easily when the Al wiring material is joined. x2 is preferably 5800 ppm by mass or less, 5600 ppm by mass or less, 5400 ppm by mass or less, or 5200 ppm by mass or less, and more preferably 5000 ppm by mass or less, 4800 ppm by mass or less, 4600 ppm by mass or less, 4400 ppm by mass or less, 4200 ppm by mass or less, or 4000 ppm by mass or less. When x2 is 300 ppm by mass or more and 5000 ppm by mass or less, the high-temperature reliability of the joint can be significantly improved, which is advantageous.

[0056] Therefore, in a preferred embodiment, the total content x2 [ppm by mass] of the second group elements in the Al wiring material preferably satisfies 200≦x2≦6000, and more preferably 300≦x2≦5000.

[0057] -Fe, Si, Ni (group 3 elements)- The Al wiring material of the present invention may further contain one or more of Fe, Si, and Ni.

[0058] In the Al wiring material of the present invention, which contains a predetermined amount of a first group element and has an average crystal grain size in a specific range in a C-section, the addition of one or more of Fe, Si, and Ni (also referred to as a "third group element") can further improve the high-temperature reliability of the joint when the Al wiring material has a small diameter. Furthermore, the addition of a third group element can improve productivity in the high-speed wiredrawing process during the production of the Al wiring material, thereby increasing adaptability to mass production. The wire diameter of the Al wiring material that can best enjoy the above-mentioned effects of the addition of a third group element is preferably 200 μm or less, and even more so when it is 120 μm or less.

[0059] When an Al wiring material has a small diameter, the load applied during bonding tends to cause early deformation of the Al wiring material, resulting in stress concentration at the neck portion corresponding to the bonding end, which tends to promote cracking from the neck portion. In contrast, the inclusion of a third group element is thought to improve the high-temperature reliability of the joint by reducing deformation at the neck portion and reducing stress concentration, even when the Al wiring material has a small diameter. It has been confirmed that the addition of a third group element alone does not sufficiently improve the high-temperature reliability of the joint. In the Al wiring material of the present invention, which contains a predetermined amount of a first group element and has an average crystal grain size in a C-section within a specific range, the unbonded region at the bonding interface is reduced, thereby promoting bonding at the neck portion (which is inherently difficult to bond). Furthermore, the inclusion of a third group element provides a synergistic effect of further improving the high-temperature reliability of the joint.

[0060] In the Al wiring material of the present invention, when the total content of the third group elements is x3 [ppm by mass], it is preferable that the relationship 10≦x3≦2000 is satisfied. If the total content of the third group elements, i.e., x3, is less than 10 ppm by mass, the effect of further improving the high-temperature reliability of the joint when the Al wiring material has a small diameter is not sufficiently obtained. x3 is preferably 12 ppm by mass or more, 14 ppm by mass or more, 16 ppm by mass or more, or 18 ppm by mass or more, more preferably 20 ppm by mass or more, 22 ppm by mass or more, 24 ppm by mass or more, 26 ppm by mass or more, 28 ppm by mass or more, or 30 ppm by mass or more. On the other hand, if x3 exceeds 2000 ppm by mass, the effect of improving productivity in a high-speed wiredrawing process tends to be insufficient. x3 is preferably 1800 ppm by mass or less or 1600 ppm by mass or less, more preferably 1500 ppm by mass or less, 1400 ppm by mass or less, 1200 ppm by mass or less, or 1000 ppm by mass or less. When x3 is 20 ppm by mass or more and 1500 ppm by mass or less, particularly when it is 20 ppm by mass or more and 1000 ppm by mass or less, it is advantageous because the high-temperature reliability of the joint can be further improved when the Al wiring material has a small diameter.

[0061] Therefore, in a preferred embodiment, the total content x3 [ppm by mass] of the third group elements in the Al wiring material preferably satisfies 10≦x3≦2000, more preferably 20≦x3≦1500, and even more preferably 20≦x3≦1000.

[0062] <High-temperature reliability evaluation> In the present invention, the high-temperature reliability of the bonded portion is evaluated by a power cycle test. The power cycle test involves repeatedly rapid heating and cooling a semiconductor device to which an Al wiring material is bonded. The device is heated over two seconds until the temperature of the bonded portion of the Al wiring material in the semiconductor device reaches 140°C, and then cooled over 25 seconds until the temperature of the bonded portion reaches 30°C. This heating and cooling cycle is repeated 50,000 or 100,000 times.

[0063] After the power cycle test, the shear strength of the first connection portion with the electrode on the semiconductor chip is measured to evaluate its high-temperature reliability. In the Al wiring material of the present invention, which contains a predetermined amount of a first group element and has an average crystal grain size in a specific range at the C cross section, the connection portion exhibits good shear strength and achieves excellent high-temperature reliability even after the above cycle is repeated 50,000 or 100,000 times.

[0064] The balance of the Al wiring material of the present invention contains Al. Al with a purity of 4N (Al: 99.99% by mass or more) can be used as the aluminum raw material when producing the Al wiring material. It is more preferable to use Al with a purity of 5N (Al: 99.999% by mass or more), which has a lower impurity content. The balance of the Al wiring material of the present invention may contain elements other than Al, as long as the effects of the present invention are not impaired. The Al content of the Al wiring material of the present invention is not particularly limited as long as the effects of the present invention are not impaired, but is preferably 95% by mass or more, 96% by mass or more, or 97% by mass or more, more preferably 98% by mass or more, 98.5% by mass or more, 98.6% by mass or more, 98.8% by mass or more, or 99% by mass or more. In a preferred embodiment, the balance of the Al wiring material of the present invention consists of Al and inevitable impurities.

[0065] The Al wiring material of the present invention may or may not have a coating mainly composed of an element other than Al on its outer periphery. In a preferred embodiment, the Al wiring material of the present invention does not have a coating mainly composed of a metal other than Al on its outer periphery. Here, "a coating mainly composed of a metal other than Al" refers to a coating in which the content of a metal other than Al is 50 mass % or more.

[0066] The Al wiring material of the present invention can provide a joint with good high-temperature reliability. Therefore, the Al wiring material of the present invention can be used in a wide range of applications requiring high-temperature reliability when connecting to connected members, and can be suitably used for connecting to connected members in industrial equipment such as transport equipment and robots (Al wiring material for industrial equipment), and can also be suitably used for connecting to connected members in various semiconductor devices including power semiconductor devices (Al wiring material for semiconductor devices).

[0067] The Al wiring material of the present invention may have any dimensions depending on its specific usage. When the Al wiring material of the present invention is an Al wire used in industrial equipment such as conveying equipment and robots, its wire diameter is not particularly limited, and for example, w may be 500 μm to 10 mm. It may also be a stranded wire made up of multiple such Al wires. When it is an Al strip, the dimensions (w×t) of its rectangular or approximately rectangular cross section are not particularly limited, and for example, w may be 500 μm to 10 mm, and t may be 50 μm to 2 mm. When the Al wiring material of the present invention is an Al bonding wire used in various semiconductor devices, including power semiconductor devices, its wire diameter is not particularly limited, and for example, the diameter may be 50 to 600 μm. When it is an Al bonding ribbon, the dimensions (w×t) of its rectangular or approximately rectangular cross section are not particularly limited, and for example, w may be 100 to 3000 μm, and t may be 50 to 600 μm.

[0068] (Manufacturing method for Al wiring material) The method for manufacturing the Al wiring material of the present invention is not particularly limited, and may be manufactured using known processing methods such as extrusion, swaging, wire drawing, and rolling. When the wire diameter becomes thin to a certain extent, it is preferable to perform wire drawing using a diamond die. Cold processing, in which wire drawing is performed at room temperature, requires a relatively simple configuration, such as a manufacturing device, and is excellent in workability. Furthermore, hot processing, in which the wire is heated and drawn, may be used to reduce resistance during wire drawing and increase productivity.

[0069] Pure metals of Al and each additive element are weighed as starting materials so that the content of each additive element falls within a specific range, and then mixed, melted, and solidified to produce an ingot. Alternatively, a master alloy containing a high concentration of the additive element may be used as the raw material for each additive element. The melting process to produce this ingot can be performed using either a batch or continuous casting method. Continuous casting has excellent productivity, but the batch method makes it easy to change the cooling temperature conditions for solidification. This ingot is then processed to the final dimensions to form the Al wiring material.

[0070] To adjust the average crystal grain size of Al wiring material in the C-section to a range of 3 to 35 μm, intermediate heat treatment during wiredrawing is effective. When a thick wire with a diameter of 1 mm or more is heat-treated in a batch process, the intermediate heat treatment may be performed, for example, at a temperature range of 200 to 500°C for 0.2 minutes to 1 hour. Specific conditions include 250°C for 30 minutes and 350°C for 1 minute. Alternatively, when a relatively small diameter wire in the 500 to 2000 μm diameter is continuously heat-treated, the wire may be heated, for example, at a temperature range of 300 to 600°C for 0.5 to 3 seconds. When more detailed optimization of conditions is desired, the temperature, time, etc. can be easily optimized by referring to these heat treatment conditions. For example, by producing prototype wiring material subjected to isothermal heat treatment under several time conditions and measuring the average crystal grain size in the C-section, desired properties can be easily obtained.

[0071] To adjust the tensile strength of Al wiring material to the range of 25 MPa to 95 MPa, it is effective to perform a tempering heat treatment at a high temperature or for a long time at the final wire diameter or a wire diameter close to the final diameter in order to reduce the amount of strain introduced into the material by wire drawing. Conditions for tempering heat treatment include, for example, heating at a relatively high temperature range of 450 to 620°C for 0.1 seconds to 5 minutes. Specific conditions include heating at 580°C for 0.2 seconds or at 450°C for 5 seconds. The temperature conditions for tempering heat treatment can be determined by, for example, changing only the furnace temperature while keeping the wire feed speed constant, checking the tensile strength of the tempered Al wiring material, and determining the heat treatment temperature to obtain the desired tensile strength. Adjusting the conditions for tempering heat treatment in combination with intermediate heat treatment makes it easier to control the tensile strength.

[0072] In the C section of the Al wiring material, <111> To adjust the crystal orientation ratio to the range of 0.5 to 35%, it is effective to appropriately control the processing texture formed by wiredrawing, the recovery of dislocations during intermediate heat treatment, and the growth of recrystallized grains. For example, when the wire diameter is in the range of 500 μm to 3000 μm, it is effective to set the average area reduction rate of the wiredrawing die to the range of 5 to 15%, or to heat the wire diameter in the range of 500 μm to 2000 μm at a temperature of 300 to 600°C for 0.5 to 3 seconds. It is also effective to perform a tempering heat treatment at or near the final wire diameter by heating at a temperature of 400 to 600°C for 0.1 to 3 minutes. Specific examples of tempering heat treatment conditions include heating at 550°C for 0.4 seconds or heating at 400°C for 5 seconds.

[0073] [Semiconductor Devices] By using the Al wiring material of the present invention to connect electrodes on a semiconductor chip to external electrodes on a lead frame or substrate, a semiconductor device can be manufactured.

[0074] In one embodiment, the semiconductor device of the present invention includes a circuit board, a semiconductor chip, and an Al wiring material for electrically connecting the circuit board and the semiconductor chip, and is characterized in that the Al wiring material is the Al wiring material of the present invention.

[0075] In the semiconductor device of the present invention, the circuit board and semiconductor chip are not particularly limited, and any known circuit board and semiconductor chip that can be used to construct a semiconductor device may be used. Alternatively, a lead frame may be used instead of the circuit board. For example, a semiconductor device may be configured including a lead frame and a semiconductor chip mounted on the lead frame, as in the semiconductor device described in Japanese Patent Laid-Open No. 2002-246542.

[0076] Examples of semiconductor devices include various semiconductor devices used in electrical appliances (e.g., computers, mobile phones, digital cameras, televisions, air conditioners, solar power generation systems, etc.) and vehicles (e.g., motorcycles, automobiles, trains, ships, aircraft, etc.), and among these, power semiconductor devices are preferred. [Example]

[0077] The present invention will be specifically described below with reference to examples, although the present invention is not limited to the examples shown below.

[0078] (sample) First, the sample preparation method will be described. The raw material Al had a purity of 5N (99.9999% by mass or more), with the remainder consisting of inevitable impurities. The alloying elements Pd, Pt, Mg, Mn, Cu, Fe, Si, and Ni had a purity of 99.9% by mass or more, with the remainder consisting of inevitable impurities. These were melted as raw materials to produce Al ingots with the compositions shown in Table 1. The ingots were extruded and swaged, and then further wiredrawn. The average reduction in area of ​​the wiredrawing dies used for wire diameters ranging from 500 μm to 2000 μm was in the range of 5 to 15%. For wire diameters ranging from 1 mm to 2 mm, intermediate heat treatment was performed at a temperature range of 400 to 600°C for 1 to 3 seconds. Subsequently, die wiredrawing was performed to final wire diameters of 100, 300, and 500 μm. After the wire drawing process was completed, a thermal refining treatment was carried out at a temperature range of 450 to 600° C. for 0.2 to 3 seconds to obtain an Al wiring material.

[0079] [Measurement of element content] The content of added elements in the Al wiring material was measured using an ICP-OES (Hitachi High-Tech Science Corporation, "PS3520UVDDII") or an ICP-MS (Agilent Technologies, Inc., "Agilent 7700x ICP-MS") as an analytical device.

[0080] [Measurement of average grain size at C cross section] The C-section of the Al wiring material was used as the measurement surface, and the average crystal grain size was measured. The measurement was performed using the EBSD method. Specifically, the area of ​​each crystal grain was measured over the entire C-section, and the circle-equivalent diameter was calculated based on the area of ​​each crystal grain. The circle-equivalent diameters were then arithmetically averaged to obtain the average crystal grain size. Five measurement surfaces (C-sections) were selected at intervals of 1 m or more along the longitudinal direction of the Al wiring material, and the obtained average crystal grain size values ​​were arithmetically averaged to obtain the average crystal grain size on the C-section.

[0081] [C section <111> Measurement of crystal orientation ratio] The C cross section of the Al wiring material was used as the measurement surface. <111> The orientation ratio of the crystal orientation was measured. The measurement was performed using the EBSD method and the analysis software attached to the device, and the procedure described above was used. <111> The orientation ratio of the crystal orientation was calculated. Five measurement surfaces (C cross sections) were selected at intervals of 1 m or more along the longitudinal direction of the Al wiring material, and the obtained orientation ratio values ​​were arithmetically averaged to obtain the ratio of the crystal orientation ratio in the C cross section. <111> The orientation ratio of the crystal orientation was calculated.

[0082] [Measurement of tensile strength] The tensile strength of the Al wiring material was measured by conducting a tensile test on the Al wiring material and measuring the maximum stress in the tensile test. The tensile strength was measured using an Instron tensile tester under the conditions of a gauge length of 100 mm, a tensile speed of 10 mm / min, and a load cell rated load of 1 kN. The measurement was performed five times, and the arithmetic average of the obtained tensile strength values ​​was used as the tensile strength of the Al wiring material.

[0083] <Connection> In the semiconductor device, the electrodes of the semiconductor chip were Al-Cu pads (2 μm thick), and the external terminals were Ni-coated Cu lead frames. Both the first connection between the semiconductor chip electrodes and the Al wiring material and the second connection between the external terminals and the Al wiring material were wedge-bonded. After connection, an aging heat treatment was performed at 300°C for 30 minutes as an accelerated evaluation simulating sample heating in a normal reliability test.

[0084] <Evaluation of bonding> -Effective bonding area ratio (EBR)- The calculation of EBR at the joint of Al wiring material is described below. EBR was evaluated for Al wiring material with wire diameters of 300 μm and 500 μm, and was calculated as the ratio (M2 / M1) of the area where a metallic bond was achieved to the area (M1) of the joint interface at the first connection portion. Specifically, a shear test was conducted on the joint, and the fractured electrodes were observed using an optical microscope or SEM. Image analysis was then used to measure the area (M1) of the joint interface and the area (M3) of the unjoined region, where the electrodes were deformed but no metallic bond was achieved, and the area (M2) where a metallic bond was achieved was calculated (M1-M3). Using the obtained areas (M1 and M2), the EBR was calculated as the ratio (M2 / M1) of M2 to M1. Specifically, the calculation formula is EBR = M2 / M1 = (M1-M3) / M1. Twenty joints were observed, and the EBR values ​​obtained were arithmetically averaged to determine the effective joint area ratio (EBR). If the EBR value is 0.9 or more, excellent bonding is obtained and is marked with "◎", if it is 0.8 or more but less than 0.9, it is good and is marked with "○", if it is 0.7 or more but less than 0.8, it is not a problem for practical use and is marked with "□", if it is 0.6 or more but less than 0.7, it is not a problem for normal use but caution is required and is marked with "△", and if it is less than 0.6, it has poor bonding and is marked with "×", and these are recorded in the "EBR" column of Table 1.

[0085] -Evaluation of chip damage- Chip damage in semiconductor devices was evaluated by dissolving the metal on the pad surface with acid and observing under a microscope (number of evaluations: N = 50). A good case with no visible cracks or bonding traces was marked with "○", a case with no cracks but some visible bonding traces (3 or less out of 50 evaluations) was marked with "△", and all other cases were marked with "×", and these were recorded in the "Chip Damage" column in Table 1.

[0086] <Evaluation of high-temperature reliability of joints> The high-temperature reliability of the joints was evaluated by conducting power cycle tests on Al wiring materials with wire diameters of 300 μm and 100 μm. In the power cycle test, the semiconductor device connected to the Al wiring material was alternately heated and cooled. Heating was performed over 2 seconds until the maximum temperature reached approximately 140°C, and then the joint temperature was cooled over 25 seconds until the temperature reached 30°C. For the Al wiring material with a wire diameter of 300 μm, this heating and cooling cycle was repeated both 50,000 times and 100,000 times, and the performance was evaluated for the Al wiring material with a wire diameter of 100 μm after this heating and cooling cycle was repeated both 50,000 times and 100,000 times.

[0087] After the power cycle test, the shear strength of the first joint was measured to evaluate its high-temperature reliability. The ratio of the shear strength S2 after the power cycle test to the shear strength S1 of the initial joint was used for evaluation, which was expressed as S2 / S1. For S2 / S1 values, a value of 0.9 or greater indicates excellent reliability and is marked with a "◎." A value of 0.8 or greater but less than 0.9 indicates good reliability and is marked with a "○." A value of 0.7 or greater but less than 0.8 indicates acceptable practical use and is marked with a "□." A value of 0.6 or greater but less than 0.7 indicates acceptable normal use but requires caution and is marked with a "△." A value less than 0.6 indicates poor high-temperature reliability and is marked with an "×." These values ​​are listed in the "High-Temperature Reliability" column in Table 1.

[0088] The evaluation results of the examples and comparative examples are shown in Table 1.

[0089] [Table 1]

[0090] All of the Al wiring materials of Examples 1 to 30 had Pd and Pt contents and average crystal grain sizes in C cross section within the ranges of the present invention, and the EBR (300 μm) was evaluated as ○ or ◎, and the high-temperature reliability also showed good results. In Examples 1 to 26 and 28 to 30, the cross section is <111> The orientation ratio of the crystal orientation was within the preferred range, the EBR (500 μm) was evaluated as ○ or ⊚, and the high-temperature reliability also showed good results. In Examples 1 to 12, 14 to 20, and 22 to 30, the tensile strength was within the preferred range, and the high-temperature reliability at a wire diameter of 300 μm and 50,000 cycles was evaluated as ◯ or ⊚, indicating even better high-temperature reliability. In Comparative Examples 1 to 5, the Pd and Pt contents were outside the range of the present invention, and in Comparative Examples 6 and 7, the average crystal grain size was outside the range of the present invention, so the EBR evaluation was poor and the high-temperature reliability was also poor.

Claims

1. When one or more of Pd and Pt are contained, and the contents of Pd and Pt are x1a [ppm by mass] and x1b [ppm by mass], respectively, 3≦x1a≦90 or 10≦x1b≦250 is satisfied, and 3≦(x1a+x1b)≦300 is satisfied, The balance is an Al wiring material containing Al, The average crystal grain size in a cross section perpendicular to the longitudinal direction of the Al wiring material is 3 to 35 μm, An Al wiring material, wherein in a cross section perpendicular to the longitudinal direction of the Al wiring material, the orientation ratio of the crystal orientation <111>, which has an angle difference of 15° or less with respect to the longitudinal direction of the Al wiring material, is 0.5% or more and 35% or less.

2. The Al wiring material according to claim 1, having a tensile strength of 25 MPa or more and 95 MPa or less.

3. When one or more of Mg, Mn, and Cu are further contained and the total content thereof is x2 [ppm by mass], The Al wiring material according to claim 1 or 2, wherein 200≦x2≦6000 is satisfied.

4. When one or more of Fe, Si, and Ni are further contained and the total content thereof is x3 [ppm by weight], The Al wiring material according to any one of claims 1 to 3, which satisfies 10≦x3≦2000.

5. The Al wiring material according to any one of claims 1 to 4, wherein the Al content is 98 mass % or more.

6. The Al wiring material according to any one of claims 1 to 5, wherein the balance consists of Al and inevitable impurities.

7. A semiconductor device comprising the Al wiring material according to any one of claims 1 to 6.

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