Semiconductor device having copper interconnect for bonding
View Patent ↗An improved wire bond is provided with the bond pads of semiconductor devices and the lead fingers of lead frames or an improved conductive lead of a TAB tape bond with the bond pad of a semiconductor device. More specifically, an improved wire bond is described wherein the bond pad on a surface of the semiconductor device comprises a layer of copper and at least one layer of metal and/or at least a barrier layer of material between the copper layer and one layer of metal on the copper layer to form a bond pad.
1. A semiconductor device having a substrate, the semiconductor device comprising:
a copper layer formed over the substrate;
an intermediate layer formed over the copper layer, wherein the intermediate layer comprises one of TaN and TiN alloys;
a first metal layer formed over the intermediate layer to form a bond pad; and
a ball formed on a bond wire, wherein a direct bond is formed between the bond wire and the copper layer, a portion of the first metal layer being formed on the ball.
2. The semiconductor device of claim 1 , wherein the first metal layer comprises one of silver metal, gold metal, a silver alloy metal, a gold alloy metal, a silver and gold alloy metal, palladium metal, a noble metal, a noble metal alloy, nickel metal, and a nickel metal alloy.
3. The semiconductor device of claim 1 , further comprising:
a second metal layer formed between the first metal layer and the copper layer.
4. The semiconductor device of claim 1 , wherein the copper layer comprises a zincated copper layer.
5. The semiconductor device of claim 3 , wherein the second metal layer comprises a barrier layer and the first metal layer comprises an adhesion promoting layer.
6. The semiconductor device of claim 1 , further comprising:
an insulative coating formed over the substrate.
7. A semiconductor device assembly comprising:
a semiconductor device having an active surface with a bond pad formed thereon, the bond pad including:
a copper layer;
an intermediate layer formed over the copper layer, wherein the intermediate layer comprises one of TaN and TiN alloys; and
a first metal layer formed over the intermediate layer; and
a ball formed on a bond wire, wherein a direct bond is formed between the bond wire and the copper layer, a portion of the first metal layer being formed on the ball.
8. The semiconductor device assembly of claim 7 , wherein the bond pad comprises a second metal layer formed between the first metal layer and the copper layer.
9. The semiconductor device of claim 8 , wherein the second metal layer comprises a barrier layer and the first metal layer comprises an adhesion promoting layer.
10. The semiconductor device of claim 7 , further comprising:
an insulative coating formed over the active surface.