A highly selective wet etch technique is used to etch a barrier layer under a metal layer from which the test pads of a semiconductor die are formed in a periphery region of the semiconductor die. The wet etch technique involves the use of a wet etchant that has a high etch rate for the barrier layer and a very low etch rate for a top dielectric layer on which the barrier layer is formed. Sidewall spacers may be formed on the sidewalls of the test pads to protect the test pads from being etched by the wet etchant. The low etch rate of the top dielectric layer reduces and/or minimizes over etching into the top dielectric layer, which reduces and/or minimizes the step height between the top dielectric layer and the test pads.

Methods of forming connector pad structures, interconnect structures, and structures thereof are disclosed. In some embodiments, a method of forming a connector pad structure includes forming an underball metallization (UBM) pad, and increasing a surface roughness of the UBM pad by exposing the UBM pad to a plasma treatment. A polymer material is formed over a first portion of the UBM pad, leaving a second portion of the UBM pad exposed.

Methods of forming connector pad structures, interconnect structures, and structures thereof are disclosed. In some embodiments, a method of forming a connector pad structure includes forming an underball metallization (UBM) pad, and increasing a surface roughness of the UBM pad by exposing the UBM pad to a plasma treatment. A polymer material is formed over a first portion of the UBM pad, leaving a second portion of the UBM pad exposed.

Methods of forming connector pad structures, interconnect structures, and structures thereof are disclosed. In some embodiments, a method of forming a connector pad structure includes forming an underball metallization (UBM) pad, and increasing a surface roughness of the UBM pad by exposing the UBM pad to a plasma treatment. A polymer material is formed over a first portion of the UBM pad, leaving a second portion of the UBM pad exposed.

Methods of forming connector pad structures, interconnect structures, and structures thereof are disclosed. In some embodiments, a method of forming a connector pad structure includes forming an underball metallization (UBM) pad, and increasing a surface roughness of the UBM pad by exposing the UBM pad to a plasma treatment. A polymer material is formed over a first portion of the UBM pad, leaving a second portion of the UBM pad exposed.

A semiconductor device includes two integrated circuit (IC) chips. The first IC chip includes substrate, a spacer connected to the substrate and including holes, wherein at least one of the holes has a first shape, and solder bumps positioned in the holes, respectively. The second IC chip includes a substrate, electrode pads extending from the substrate and connected to the solder bumps, respectively. At least one of the electrode pads that corresponds to the at least one of the solder bumps has a second shape, and the first shape and the second shape are non-coextensive such that there is at least one gap between the first shape and the second shape when projected on each other.

An integrated circuit has corner regions and non-corner regions between the corner regions and includes a semiconductor substrate, conductive pads, passivation layer, post-passivation layer, first conductive posts, and second conductive posts. The conductive pads are disposed over the semiconductor substrate. The passivation layer and the post-passivation layer are sequentially disposed over the conductive pads. The first conductive posts and the second conductive posts are disposed on the post-passivation layer and are electrically connected to the conductive pads. The first conductive posts are disposed in the corner regions and the second conductive posts are disposed in the non-corner regions. Each of the first conductive posts has a body portion and a protruding portion connected to the body portion. A central axis of the body portion of the first conductive post has an offset from a central axis of the protruding portion of the first conductive post.

An integrated circuit has corner regions and non-corner regions between the corner regions and includes a semiconductor substrate, conductive pads, passivation layer, post-passivation layer, first conductive posts, and second conductive posts. The conductive pads are disposed over the semiconductor substrate. The passivation layer and the post-passivation layer are sequentially disposed over the conductive pads. The first conductive posts and the second conductive posts are disposed on the post-passivation layer and are electrically connected to the conductive pads. The first conductive posts are disposed in the corner regions and the second conductive posts are disposed in the non-corner regions. Each of the first conductive posts has a body portion and a protruding portion connected to the body portion. A central axis of the body portion of the first conductive post has an offset from a central axis of the protruding portion of the first conductive post.

A semiconductor package includes a first semiconductor chip including a first substrate and a first bonding layer disposed on the first substrate, and having a flat first outer surface provided by the first bonding layer; and a second semiconductor chip disposed on the first outer surface of the first semiconductor chip, including a second substrate and a second bonding layer disposed on the second substrate, and having a flat second outer surface provided by the second bonding layer and contacting the first outer surface of the first semiconductor chip. The first bonding layer includes a first outermost insulating layer providing the first outer surface, a first internal insulating layer stacked between the first outermost insulating layer and the first substrate, first external marks disposed in the first outermost insulating layer and spaced apart from each other, and first internal marks interlaced with the first external marks within the first internal insulating layer.