Semiconductor device, imaging unit, and electronic apparatus

Provided is a semiconductor device having high planarity in an in-plane direction. This semiconductor device includes a semiconductor substrate, a first plating film pattern, a second plating film pattern, and an insulating layer. The semiconductor substrate has a first surface, and a second surface on a side opposite to the first surface. The first plating film pattern includes a first portion that covers a first regional portion of the first surface, and a second portion that is stacked to cover a portion of the first portion. The second plating film pattern includes a third portion that covers a second regional portion different from the first regional portion of the first surface, and also includes a fourth portion that is stacked to cover a portion of the third portion. A portion between the second portion and the fourth portion is filled with the insulating layer.