A semiconductor device includes an insulating film, a metal film, and an adhesion intermediate film arranged between the insulating film and the metal film, and the adhesion intermediate film includes a first adhesion layer, a stress control layer, a second adhesion layer, and a barrier metal layer, which are mutually different and are arranged sequentially in a direction from the insulating film toward the metal film. The insulating film may contain silicon oxide.

Techniques are provided for suppressing the accumulation of holes in floating region and improving the switching time of a semiconductor device such as an Insulated Gate Bipolar. The semiconductor device includes a trench gate and a trench emitter formed in a semiconductor substrate, and a floating region of a first conductivity type formed in the semiconductor substrate sandwiched between the trench gate and the trench emitter. The bottom of the floating region is located below the bottom of the trench gate and the trench emitter, and the floating region has a crystal defect region including crystal defects selectively formed at a position near an upper surface of the semiconductor substrate in the floating region.

Provided is a semiconductor device, comprising: a semiconductor substrate; an interlayer dielectric film provided on the semiconductor substrate, having contact holes provided thereon, wherein the contact holes include a contact hole with a stepped portion on a sidewall; and a contact portion provided in the contact hole, wherein the contact portion has a barrier layer provided on the sidewall and a bottom surface of the contact hole, wherein the barrier layer has: a first region in direct contact with the stepped portion; and a second region in direct contact with the sidewall of the contact hole in a region different from the first region, wherein when a film thickness of a thickest portion of the first region is T and a film thickness of a thinnest portion of the second region is t, 0.3Tt0.95T is satisfied.

Provided is a manufacturing method including: forming a contact trench in a mesa portion; forming a contact dielectric film on a side wall and a bottom surface of the contact trench; etching a part of the contact dielectric film to expose a first emitter portion on the side wall of the contact trench and to expose a region of a second conductivity type on the bottom surface of the contact trench; and filling an inside of the contact trench with a conductive material to bring the conductive material into contact with the first emitter portion and the region of the second conductivity type.