A process for making at least one porous area (ZP) of a microelectronic structure in at least one part of an conducting active layer (6), the active layer (6) forming a front face of a stack, the stack comprising a back face (2) of conducting material and an insulating layer (4) interposed between the active layer (6) and the back face (2), said process comprising the steps of: a) making at least one contact pad (14) between the back face (2) and the active layer (6) through the insulation layer (2), b) placing the stack into an electrochemical bath, c) applying an electrical current between the back face (2) and the active layer (6) through the contact pad (14) causing porosification of an area (ZP) of the active layer (6) in the vicinity of the contact pad (14), d) forming the microelectronic structure.

A method for manufacturing a micromechanical timepiece part starting from a silicon-based substrate, including, forming pores on the surface of at least one part of a surface of said silicon-based substrate of a determined depth, entirely filling the pores with a material chosen from diamond, diamond-like carbon, silicon oxide, silicon nitride, ceramics, polymers and mixtures thereof, in order to form, in the pores, a layer of the material of a thickness at least equal to the depth of the pores. A micromechanical timepiece part including a silicon-based substrate which has, on the surface of at least one part of a surface of the silicon-based substrate, pores of a determined depth, the pores being filled entirely with a layer of a material chosen from diamond, diamond-like carbon, silicon oxide, silicon nitride, ceramics, polymers and mixtures thereof, of a thickness at least equal to the depth of the pores.

A method of producing a semiconductor device includes providing a carrier structure having a semiconductor substrate; applying or introducing a precursor substance onto or into the carrier structure, treating the precursor substance for producing a porous matrix structure; introducing a functionalization substance into the porous matrix structure.

A micromechanical pressure sensor device including a semiconductor base substrate of a first doping type on which an intermediate layer of the first doping type is situated, a cavity sealed by a sealing layer of a second doping type and including a reference pressure, a first grating of the second doping type, suspended inside the cavity on a buried connection region of the second doping type, the buried connection region laterally extending away from the cavity into the semiconductor base material, a second grating of the second doping type, situated on a side of the diaphragm region pointing to the cavity and suspended on the diaphragm region, the first grating and the second grating being electrically insulated from each other and forming a capacitance, a first connection electrically connected to the first grating via the buried connection region, and a second connection electrically connected to the second grating.

An ultra-high charge density electret is disclosed. The ultra-high charge density electret includes a three-dimensional structure having a plurality of sidewalls. A porous silicon dioxide film is formed on the plurality of sidewalls, and the porous silicon dioxide film is charged with a plurality of positive or negative ions.

An ultra-high charge density electret is disclosed. The ultra-high charge density electret includes a three-dimensional structure having a plurality of sidewalls. A porous silicon dioxide film is formed on the plurality of sidewalls, and the porous silicon dioxide film is charged with a plurality of positive or negative ions.

Provided are monolithic structures comprising one or more suspended, nanoporous membranes that are in contact with one or more fluidic cavities, methods of making same, and exemplary uses of same. The monolithic structures can be formed using a transmembrane etch. The monolithic structures can be used, as examples, as filters and filtration modules in microfluidic devices, dialysis devices, and concentration devices in laboratory, industrial, and medical processes.

A method comprises forming etching islands on a substrate and exposing the substrate with etching islands to a solution that reacts with the etching islands to form a filter passage of interconnected pores in the substrate. The filter passage has an inlet into the substrate and an outlet from the substrate.

A method of processing a semiconductor substrate having a first conductivity type includes, in part, forming a first implant region of a second conductivity type in the semiconductor substrate where the first implant region is characterized by a first depth, forming a second implant region of the first conductivity type in the semiconductor substrate where the second implant region is characterized by a second depth smaller than the first depth, forming a porous layer within the semiconductor substrate where the porous layer is adjacent the first implant region, and growing an epitaxial layer on the semiconductor substrate thereby causing the porous layer to collapse and form a cavity.

A fabrication method includes: (1) forming a wire array on a fabrication substrate; (2) forming a porous layer within a portion of the fabrication substrate below the wire array; (3) separating the porous layer and the wire array from a remaining portion of the fabrication substrate; and (4) affixing top ends of the wire array to a target substrate.