Provided is a package structure including a die, an encapsulant, a through via, a first dielectric layer, a conductive line structure, an adhesion promotion layer, a second dielectric layer and a connector. The encapsulant is formed aside the die. The through via is formed aside the die and penetrates through the encapsulant. The first dielectric layer is formed overlying the die, the encapsulant and the through via. The conductive line structure includes a pad over the first dielectric layer. The adhesion promotion layer overlays a first portion of a top surface and a sidewall of the pad and overlying the first dielectric layer. The second dielectric layer overlays the adhesion promotion layer. The connector is in contact with a second portion of the top surface of the pad. The second portion of the top surface of the pad is exposed by the adhesion promotion layer.

A method of forming a semiconductor device includes forming an opening in a dielectric layer, and forming a barrier layer in the opening. A combined liner layer is formed over the barrier layer by first forming a first liner layer over the barrier layer, and forming a second liner layer over the first liner layer, such that the first liner layer and the second liner layer intermix. A conductive material layer is formed over the combined liner layer, and a thermal process is performed to reflow the conductive material layer.

A method of forming a semiconductor device includes forming an opening in a dielectric layer, and forming a barrier layer in the opening. A combined liner layer is formed over the barrier layer by first forming a first liner layer over the barrier layer, and forming a second liner layer over the first liner layer, such that the first liner layer and the second liner layer intermix. A conductive material layer is formed over the combined liner layer, and a thermal process is performed to reflow the conductive material layer.