Reliability of a semiconductor device is improved. A slope is provided on a side face of an interconnection trench in sectional view in an interconnection width direction of a redistribution layer. The maximum opening width of the interconnection trench in the interconnection width direction is larger than the maximum interconnection width of the redistribution layer in the interconnection width direction, and the interconnection trench is provided so as to encapsulate the redistribution layer in plan view.

A liquid encapsulation resin composition contains a silica (A), an epoxy resin (B), a curing agent (C), a curing accelerator (D), and a triblock copolymer (E) expressed by the formula (1): XYX, where X is a segment block including a polymer of methyl methacrylate and Y is a segment block including a polymer of monomer components containing 2-ethylhexyl acrylate. The percentage of the triblock copolymer (E) to the total of the epoxy resin (B), the curing agent (C), and the curing accelerator (D) is equal to or greater than 1.0% by mass and equal to or less than 9.5% by mass.

A semiconductor structure and a method of forming the same are disclosed. A method of forming a semiconductor structure includes the following operations. An insulating layer is formed over a substrate. A metal feature is formed in the insulating layer. An argon-containing plasma treatment is performed to the insulating layer and the metal feature.

An adhesion layer may be formed over portions of a redistribution layer (RDL) in a redistribution structure of a semiconductor device package. The portions of the RDL over which the adhesion layer is formed may be located in the shadow of (e.g., the areas under and/or over and within the perimeter of) one or more TIVs that are connected with the redistribution layer structure. The adhesion layer, along with a seed layer on which the portions of the RDL are formed, encapsulate the portions of the RDL in the shadow of the one or more TIVs, which promotes and/or increases adhesion between the portions of the RDL and the polymer layers of the redistribution structure.