Abstract: A method for fabricating a semiconductor device is disclosed. A packaged semiconductor device is provided having copper ball bonds attached to aluminum pads. The packaged device is treated for at least one cycle at a temperature in the range from about 250° C. to 270° C. for a period of time in the range from about 20 s to 40 s.

Abstract: A method for fabricating a semiconductor device is disclosed. A packaged semiconductor device is provided having copper ball bonds attached to aluminum pads. The packaged device is treated for at least one cycle at a temperature in the range from about 250° C. to 270° C. for a period of time in the range from about 20 s to 40 s.

Abstract: A connection formed by a copper wire (112) alloyed with a noble metal in a first concentration bonded to a terminal pad (101) of a semiconductor chip; the end of the wire being covered with a zone (302) including an alloy of copper and the noble metal in a second concentration higher than the first concentration. When the noble metal is gold, the first concentration may range from about 0.5 to 2.0 weight %, and the second concentration from about 1.0 to 5.0 weight %. The zone of the alloy of the second concentration may have a thickness from about 20 to 50 nm.

Abstract: A metallic interconnect structure (200) for connecting a gold bump (205) and a contact pad (212), as used for example in semiconductor flip-chip assembly. A first region (207) of binary AuSn2 intermetallic is adjacent to the gold bump. A region (208) of binary AuSn4 intermetallic is adjacent to the first AuSn2 region. Then, a region (209) of binary gold-tin solid solution is adjacent to the AuSn4 region, and a second region (210) of binary AuSn2 intermetallic is adjacent to the solid solution region. The second AuSn2 region is adjacent to a nickel layer (213) (preferred thickness about 0.08 ?m), which covers the copper pad. The nickel layer insures that the gold/tin intermetallics and solutions remain substantially free of copper and thus avoid ternary compounds, providing stabilized gold bump/solder connections.

Abstract: A metallic interconnect structure (200) for connecting a gold bump (205) and a copper pad (212), as used for example in semiconductor flip-chip assembly. A first region (207) of binary AuSn2 intermetallic is adjacent to the gold bump. A region (208) of binary AuSn4 intermetallic is adjacent to the first AuSn2 region. Then, a region (209) of binary gold-tin solid solution is adjacent to the AuSn4 region, and a second region (210) of binary AuSn2 intermetallic is adjacent to the solid solution region. The second AuSn2 region is adjacent to a nickel layer (213) (preferred thickness about 0.08 ?m), which covers the copper pad. The nickel layer insures that the gold/tin intermetallics and solutions remain substantially free of copper and thus avoid ternary compounds, providing stabilized gold bump/solder connections.

Abstract: A metallic interconnect structure (200) for connecting a gold bump (205) and a copper pad (212), as used for example in semiconductor flip-chip assembly. A first region (207) of binary AuSn2 intermetallic is adjacent to the gold bump. A region (208) of binary AuSn4 intermetallic is adjacent to the first AuSn2 region. Then, a region (209) of binary gold-tin solid solution is adjacent to the AuSn4 region, and a second region (210) of binary AuSn2 intermetallic is adjacent to the solid solution region. The second AuSn2 region is adjacent to a nickel layer (213) (preferred thickness about 0.08 ?m), which covers the copper pad. The nickel layer insures that the gold/tin intermetallics and solutions remain substantially free of copper and thus avoid ternary compounds, providing stabilized gold bump/solder connections.

Abstract: A semiconductor device contact structure practically eliminating the copper diffusion into the solder as well as the current crowding at the contact with the subsequent electromigration in the solder. A column-like electroplated copper stud (108) is on each contact pad. The stud is sized to provide low, uniform electrical resistance in order to spread the current from the contact to an approximately uniform, low density. Preferably, the stud height (108a) is at least ten times the thickness of the copper interconnect layer (104). Stud (108) is capped by an electroplated nickel layer (109) thick enough (preferably about 2 ?m) to suppress copper diffusion from stud (108) into solder body (120), thus practically inhibiting intermetallic compound formation and Kirkendall voiding.

Abstract: A solder joint (200) has a first contact pad 114 and a second contact pad 124 of a first metal, preferably copper, facing each other across a gap. A coat and 125, respectively) of a second metal, preferably nickel, covers each pad. A layer 201 of crystals of first intermetallic compounds, such as Ni3Sn4 and (Ni, Cu)3Sn4, covers the surface of each coat. Isolated crystals 202 of second intermetallic compounds, such as Cu6Sn5 and (Cu, Ni)6Sn5, different from the first intermetallic compounds, are dispersed on top of the layer 201 of crystals of the first intermetallic compounds. A solder alloy 203 including a third metal, preferably tin, and the first metal fills the gap. The solder alloy 203 may further include a fourth metal, preferably selected from a group of metals including silver, zinc, and indium.

Abstract: A metallic interconnect structure (200) for connecting a gold bump (205) and a copper pad (212), as used for example in semiconductor flip-chip assembly. A first region (207) of binary AuSn2 intermetallic is adjacent to the gold bump. A region (208) of binary AuSn4 intermetallic is adjacent to the first AuSn2 region. Then, a region (209) of binary gold-tin solid solution is adjacent to the AuSn4 region, and a second region (210) of binary AuSn2 intermetallic is adjacent to the solid solution region. The second AuSn2 region is adjacent to a nickel layer (213) (preferred thickness about 0.08 ?m), which covers the copper pad. The nickel layer insures that the gold/tin intermetallics and solutions remain substantially free of copper and thus avoid ternary compounds, providing stabilized gold bump/solder connections.

Abstract: A semiconductor device contact structure practically eliminating the copper diffusion into the solder as well as the current crowding at the contact with the subsequent electromigration in the solder. A column-like electroplated copper stud (108) is on each contact pad. The stud is sized to provide low, uniform electrical resistance in order to spread the current from the contact to an approximately uniform, low density. Preferably, the stud height (108a) is at least ten times the thickness of the copper interconnect layer (104). Stud (108) is capped by an electroplated nickel layer (109) thick enough (preferably about 2 ?m) to suppress copper diffusion from stud (108) into solder body (120), thus practically inhibiting intermetallic compound formation and Kirkendall voiding.

Abstract: A metal interconnection for two workplaces such as a semiconductor chip and an insulating substrate. The first workpiece (101) has a first contact pad (201) with a gold stud (110); the second workplace (103) is covered with an insulating layer (213) and a window in the layer to a second contact pad (211). The interconnection between the second pad and the gold stud is a 278° C. eutectic structure (111) with about 80 weight percent gold and about 20 weight percent tin. The eutectic structure has a Young's modulus of 59.2 GPa and a lamellar micro-structure of the phases Au5Sn and AuSn. There is substantially no metallic tin at the second contact pad.

Abstract: A method for reducing gold embrittlement in solder joints, and a copper-bearing solder according to the method, are disclosed. Embodiments of the invention comprise adding copper to non-copper based solder, such as tin-lead solder. The embodiments may further comprise using the copper-bearing solder as a solder interconnect on a gold-nickel pad.

Abstract: A metal interconnect structure (100) comprising a bond pad (101), which has copper with at least 70 volume percent composed of crystal grains expanding more than 1 ?m in their main direction, and 30 or less volume percent composed of crystal grains, which expand less than 1 ?m in their main crystal direction. A body (102) of tin alloy is in contact with the bond pad.

Abstract: A metal interconnect structure (100) comprising a bond pad (101), which has copper with at least 70 volume percent composed of crystal grains expanding more than 1 ?m in their main direction, and 30 or less volume percent composed of crystal grains, which expand less than 1 ?m in their main crystal direction. A body (102) of tin alloy is in contact with the bond pad.

Abstract: Method for assembling a semiconductor device having fatigue-resistant interconnection fillet provides a semiconductor chip with at least one solder bump comprising an alloy of tin and lead with a melting temperature higher than the solder paste used. Further, a solder paste (preferably binary) is provided, which comprises tin and about 2.5 weight percent silver, and has a melting temperature of about 221° C. The solder bump is brought in contact with the solder paste, the bump is partially immersed in the paste, and thermal energy is supplied to reflow the solder paste at about 235° C. The amount of energy and time after the reflow of the paste is controlled so that the molten paste dissolves a pre-determined amount of the solder bump (lead and tin) to form a ternary alloy of about eutectic composition (about 1.62 weight % Ag, 36.95 weight % Pb, 61.43 weight % Sn) without melting the solder bump.

Abstract: A method for reducing gold embrittlement in solder joints, and a copper-bearing solder according to the method, are disclosed. Embodiments of the invention comprise adding copper to non-copper based solder, such as tin-lead solder. The embodiments may further comprise using the copper-bearing solder as a solder interconnect on a gold-nickel pad.

Abstract: A method for reducing gold embrittlement in solder joints, and a copper-bearing solder according to the method, are disclosed. Embodiments of the invention comprise adding copper to non-copper based solder, such as tin-lead solder. The embodiments may further comprise using the copper-bearing solder as a solder interconnect on a gold-nickel pad.

Abstract: A solder comprising a ternary alloy of tin, lead, and silver, providing approximately the eutectic melting temperature and about 0.7 to 1.5 weight percent silver. In one embodiment, the ternary solder alloy comprises the composition of about 61.0 weight percent tin, about 37.5 weight percent lead, and about 1.5 percent weight percent silver. In another embodiment, the ternary solder alloy comprises the composition of about 61.3 weight percent tin, about 37.7 weight percent lead, and about 1.0 percent weight percent silver. At these silver concentrations, precipitated Ag3Sn particles (210), embedded in the matrix of the eutectic alloy (201), can pin down (222) moving dislocations (220) and thus increase the fatigue resistance of the solder.

Abstract: A metal interconnect structure (100) comprising a bond pad (110) of copper; a body (103) of eutectic alloy in contact with the bond pad, this alloy including copper; and a contact pad (120) comprising copper in contact with the alloy body. When the eutectic alloy is tin/lead, the alloy includes copper in an amount greater than 0.08 weight percent and less than 2.0 weight percent. When the eutectic alloy is tin/silver, the alloy includes copper in an amount greater than 0.9 weight percent and less than 2.0 weight percent.

Abstract: Method for assembling a semiconductor device having fatigue-resistant interconnection fillet provides a semiconductor chip with at least one solder bump comprising an alloy of tin and lead with a melting temperature higher than the solder paste used. Further, a solder paste (preferably binary) is provided, which comprises tin and about 2.5 weight percent silver, and has a melting temperature of about 221° C. The solder bump is brought in contact with the solder paste, the bump is partially immersed in the paste, and thermal energy is supplied to reflow the solder paste at about 235° C. The amount of energy and time after the reflow of the paste is controlled so that the molten paste dissolves a pre-determined amount of the solder bump (lead and tin) to form a ternary alloy of about eutectic composition (about 1.62 weight % Ag, 36.95 weight % Pb, 61.43 weight % Sn) without melting the solder bump.