Process for manufacturing an insulated interconnection through a body of semiconductor material and corresponding semiconductor device

The process for manufacturing a through insulated interconnection is performed by forming, in a body (1) of semiconductor material, a trench (2) extending from the front (7) of the body (1) for a thickness portion thereof; filling the trench with dielectric material (6); thinning the body starting from the rear (5) until the trench (2), so as to form an insulated region (3) surrounded by dielectric material; and forming a conductive region (30b) extending inside said insulated region (3) between the front and the rear of the body and having a higher conductivity than the first body (1). The conductive region (8, 25, 28, 30b) includes a heavily doped semiconductor region (30b), made prior to filling of the trench.