An integrated circuit device wafer includes a silicon wafer substrate and a back side metallization structure. The back side metallization structure includes a first adhesion layer on the back side of the substrate, a first metal later over the first adhesion layer, a second metal layer over the first metal layer, and a second adhesion layer over the second metal layer. The first includes at least one of: silicon nitride and silicon dioxide. The first metal layer includes titanium. The second metal layer includes nickel. The second adhesion layer includes at least one of: silver, gold, and tin. An indium preform is placed between the second adhesion layer and the lid and the indium preform is reflowed.

An integrated circuit device wafer includes a silicon wafer substrate and a back side metallization structure. The back side metallization structure includes a first adhesion layer on the back side of the substrate, a first metal later over the first adhesion layer, a second metal layer over the first metal layer, and a second adhesion layer over the second metal layer. The first includes at least one of: silicon nitride and silicon dioxide. The first metal layer includes titanium. The second metal layer includes nickel. The second adhesion layer includes at least one of: silver, gold, and tin. An indium preform is placed between the second adhesion layer and the lid and the indium preform is reflowed.

An integrated circuit device wafer includes a silicon wafer substrate and a back side metallization structure. The back side metallization structure includes a first adhesion layer on the back side of the substrate, a first metal later over the first adhesion layer, a second metal layer over the first metal layer, and a second adhesion layer over the second metal layer. The first includes at least one of: silicon nitride and silicon dioxide. The first metal layer includes titanium. The second metal layer includes nickel. The second adhesion layer includes at least one of: silver, gold, and tin. An indium preform is placed between the second adhesion layer and the lid and the indium preform is reflowed.

An integrated circuit device wafer includes a silicon wafer substrate and a back side metallization structure. The back side metallization structure includes a first adhesion layer on the back side of the substrate, a first metal later over the first adhesion layer, a second metal layer over the first metal layer, and a second adhesion layer over the second metal layer. The first includes at least one of: silicon nitride and silicon dioxide. The first metal layer includes titanium. The second metal layer includes nickel. The second adhesion layer includes at least one of: silver, gold, and tin. An indium preform is placed between the second adhesion layer and the lid and the indium preform is reflowed.

An integrated circuit device wafer includes a silicon wafer substrate and a back side metallization structure. The back side metallization structure includes a first adhesion layer on the back side of the substrate, a first metal later over the first adhesion layer, a second metal layer over the first metal layer, and a second adhesion layer over the second metal layer. The first includes at least one of: silicon nitride and silicon dioxide. The first metal layer includes titanium. The second metal layer includes nickel. The second adhesion layer includes at least one of: silver, gold, and tin.

An integrated circuit device wafer includes a silicon wafer substrate and a back side metallization structure. The back side metallization structure includes a first adhesion layer on the back side of the substrate, a first metal later over the first adhesion layer, a second metal layer over the first metal layer, and a second adhesion layer over the second metal layer. The first includes at least one of: silicon nitride and silicon dioxide. The first metal layer includes titanium. The second metal layer includes nickel. The second adhesion layer includes at least one of: silver, gold, and tin.

A package structure includes a substrate, a chip disposed on the substrate and having a backside surface away from the substrate, a heat sink disposed above the substrate and having a surface facing the back side surface, and a thermal interface material disposed between the chip and the heat sink. There is no organic adhesive between the chip and the heat sink. A method for forming the package structure is also provided.