Integrated circuit chip and fabrication method

An integrated circuit chip includes a substrate die and integrated circuits and a layer incorporating a front electrical interconnect network formed on a front face of the substrate die. A local electrical connection via made of an electrically conductive material is formed in a hole of the substrate die. The via is linked to a connection portion of the electrical interconnect network. An electrical connection pillar made of an electrically conductive material is formed on a rear part of the electrical connection via. A local external protection layer at least partly covers the electrical connection via and the electrical connection pillar.