Patent ID: 7786014

Claim:
A method for manufacturing an electronic device comprising a vertical interconnect through a semiconductor substrate having a first surface on a first side and a second surface on a second side, the vertical interconnect extending from the first surface to the second surface, the method comprising the successive steps of: providing the substrate with a sacrificial buried layer arranged in between the first and second surface; providing the substrate with a trench extending from the first surface to the sacrificial buried layer by removing material from the first side of the substrate, the sacrificial buried layer therewith being exposed over a first area, the sacrificial buried layer having a first cross section taken parallel to the plane of the first area which first cross section is larger than the first area and overlaps with the first area, and providing the substrate with a hole extending from the second surface to the sacrificial buried layer by removing material from the second side of the substrate selectively with respect to the sacrificial buried layer, the sacrificial buried layer therewith being exposed over a second area, the sacrificial buried layer having a second cross section taken parallel to the plane of the second area which second cross section is larger than and overlaps with the second area, and the second area being smaller than the first area; and wherein the step of providing the substrate with a sacrificial buried layer comprises the successive steps of: providing a substrate without the sacrificial buried layer, providing the trench before performing the step for providing the hole, the step of providing the trench including anisotropic removal of material from the first side of the substrate such that the trench is formed having a bottom with a bottom area located within the semiconductor substrate in between the first and second surface, and after providing of the trench and before providing the hole, performing the step of providing the sacrificial buried layer such that it is provided in between the first and second surfaces of the semiconductor substrate by forming a cavity at the bottom of the trench, the cavity having a cross section parallel to the plane of the bottom of the trench, which cross section is larger than the area of the bottom of the trench, and filling at least part of the cavity with a sacrificial material.