A semiconductor device includes a conductive component on a substrate, a passivation layer on the substrate and including an opening that exposes at least a portion of the conductive component, and a pad structure in the opening and located on the passivation layer, the pad structure being electrically connected to the conductive component. The pad structure includes a lower conductive layer conformally extending on an inner sidewall of the opening, the lower conductive layer including a conductive barrier layer, a first seed layer, an etch stop layer, and a second seed layer that are sequentially stacked, a first pad layer on the lower conductive layer and at least partially filling the opening, and a second pad layer on the first pad layer and being in contact with a peripheral portion of the lower conductive layer located on the top surface of the passivation layer.

Implementations of a semiconductor package may include a pin coupled to a substrate. The pin may include a titanium sublayer, a nickel sublayer, and one of a silver and tin intermetallic layer or a copper and tin intermetallic layer, the one of the silver and tin intermetallic layer or the copper and tin intermetallic layer having a melting temperature greater than 260 degrees Celsius. The one of the silver and tin intermetallic layer or the copper and tin intermetallic layer may be formed by reflowing a tin layer and one of a silver layer or copper layer with a silver layer of the substrate where the substrate may be directly coupled to the one of the silver and tin intermetallic layer or the copper and tin intermetallic layer. The substrate may include a copper layer that was directly coupled with the silver layer before the reflow.

A method of forming a semiconductor package. Implementations include forming on a die backside an intermediate metal layer having multiple sublayers, each including a metal selected from the group consisting of titanium, nickel, copper, silver, and combinations thereof. A tin layer is deposited onto the intermediate metal layer and is then reflowed with a silver layer of a substrate to form an intermetallic layer having a melting temperature above 260 degrees Celsius and including an intermetallic consisting of silver and tin and/or an intermetallic consisting of copper and tin. Another method of forming a semiconductor package includes forming a bump on each of a plurality of exposed pads of a top side of a die, each exposed pad surrounded by a passivation layer, each bump including an intermediate metal layer as described above and a tin layer coupled to the intermediate metal layer is reflowed to form an intermetallic layer.

A method of forming a semiconductor package. Implementations include forming on a die backside an intermediate metal layer having multiple sublayers, each including a metal selected from the group consisting of titanium, nickel, copper, silver, and combinations thereof. A tin layer is deposited onto the intermediate metal layer and is then reflowed with a silver layer of a substrate to form an intermetallic layer having a melting temperature above 260 degrees Celsius and including an intermetallic consisting of silver and tin and/or an intermetallic consisting of copper and tin. Another method of forming a semiconductor package includes forming a bump on each of a plurality of exposed pads of a top side of a die, each exposed pad surrounded by a passivation layer, each bump including an intermediate metal layer as described above and a tin layer coupled to the intermediate metal layer is reflowed to form an intermetallic layer.

A semiconductor device includes a conductive component on a substrate, a passivation layer on the substrate and including an opening that exposes at least a portion of the conductive component, and a pad structure in the opening and located on the passivation layer, the pad structure being electrically connected to the conductive component. The pad structure includes a lower conductive layer conformally extending on an inner sidewall of the opening, the lower conductive layer including a conductive barrier layer, a first seed layer, an etch stop layer, and a second seed layer that are sequentially stacked, a first pad layer on the lower conductive layer and at least partially filling the opening, and a second pad layer on the first pad layer and being in contact with a peripheral portion of the lower conductive layer located on the top surface of the passivation layer.

A method for sawing a semiconductor wafer is provided. The method includes sawing the semiconductor wafer with a first dicing blade to form a first opening. The semiconductor wafer includes a dicing tape and a substrate attached to the dicing tape. The first opening is formed in the upper portion of the substrate. The method also includes sawing the semiconductor wafer with a second dicing blade from the first opening to form a second opening under the first opening and in the middle portion of the substrate. The method further includes sawing the semiconductor wafer with a third dicing blade from the second opening to form a third opening under the second opening and penetrating the lower portion of the substrate, so that the semiconductor wafer is divided into two dies. The first dicing blade, the second dicing blade, and the third dicing blade have different widths.

A method for sawing a semiconductor wafer is provided. The method includes sawing the semiconductor wafer with a first dicing blade to form a first opening. The semiconductor wafer includes a dicing tape and a substrate attached to the dicing tape. The first opening is formed in the upper portion of the substrate. The method also includes sawing the semiconductor wafer with a second dicing blade from the first opening to form a second opening under the first opening and in the middle portion of the substrate. The method further includes sawing the semiconductor wafer with a third dicing blade from the second opening to form a third opening under the second opening and penetrating the lower portion of the substrate, so that the semiconductor wafer is divided into two dies. The first dicing blade, the second dicing blade, and the third dicing blade have different widths.

A method of forming a semiconductor package. Implementations include forming on a die backside an intermediate metal layer having multiple sublayers, each including a metal selected from the group consisting of titanium, nickel, copper, silver, and combinations thereof. A tin layer is deposited onto the intermediate metal layer and is then reflowed with a silver layer of a substrate to form an intermetallic layer having a melting temperature above 260 degrees Celsius and including an intermetallic consisting of silver and tin and/or an intermetallic consisting of copper and tin. Another method of forming a semiconductor package includes forming a bump on each of a plurality of exposed pads of a top side of a die, each exposed pad surrounded by a passivation layer, each bump including an intermediate metal layer as described above and a tin layer coupled to the intermediate metal layer is reflowed to form an intermetallic layer.

A method of forming a semiconductor package. Implementations include forming on a die backside an intermediate metal layer having multiple sublayers, each including a metal selected from the group consisting of titanium, nickel, copper, silver, and combinations thereof. A tin layer is deposited onto the intermediate metal layer and is then reflowed with a silver layer of a substrate to form an intermetallic layer having a melting temperature above 260 degrees Celsius and including an intermetallic consisting of silver and tin and/or an intermetallic consisting of copper and tin. Another method of forming a semiconductor package includes forming a bump on each of a plurality of exposed pads of a top side of a die, each exposed pad surrounded by a passivation layer, each bump including an intermediate metal layer as described above and a tin layer coupled to the intermediate metal layer is reflowed to form an intermetallic layer.

A 3D IC package includes a bottom die having a back interconnect side opposing a front device side, the back interconnect side having a plurality of bottom die interconnects extending thereto. A top die has a front device side opposing a back side, the front device side having a plurality of top die interconnects. An interposer includes a redistribution layer (RDL) between the bottom die and the top die, the RDL including a plurality of wiring layers extending from back side RDL interconnects thereof to front side RDL interconnects thereof. An under bump metallization (UBM) couples the back side RDL interconnects to the plurality of top die interconnects at a first location, and the front side RDL interconnects are coupled to the plurality of bottom die interconnects at a second location. The first location and second location may not overlap.