Abstract: An electrostatic electroacoustical transducer contains an electrically conductive fixed electrode plate having an active surface with recesses. A conductive or semiconductive flexible diaphragm is disposed at a distance from the active surface of the electrode plate and within the recesses. An insulating device is disposed between the electrode plate and the diaphragm.

Abstract: An electrostatic electroacoustical transducer contains an electrically conductive fixed electrode plate having an active surface with recesses. A conductive or semiconductive flexible diaphragm is disposed at a distance from the active surface of the electrode plate and within the recesses. An insulating device is disposed between the electrode plate and the diaphragm.

Abstract: The invention concerns a microphone, in particular, for manufacturing based on silicon micromechanical technology. The microphone comprises a first plate and a second plate positioned to form a gap with said first plate at a small separation therefrom. An acoustical membrane is integrated into the first plate. The air gap between the first and second plates is substantially smaller than a characteristic width dimension of the device so that a narrow slot-like entrance between the two plates is thereby defined. An acoustical signal entering into the air gap is guided in a wave guide fashion between the first and second plates to be detected by the acoustical membrane. In this manner a microphone having small lateral dimensions but nevertheless good acoustical sensitivity can be manufactured, in particular, using micromechanical techniques based on silicon technology.

Abstract: An apparatus and method for selectively electrochemically etching a surface is described. The use of the apparatus and the related method allows the establishment of etched planar surface which may be inclined with respect to the original surface.The apparatus has a cathode and multiple connectors which attach to the workpiece whose surface is to be etched. When the apparatus is operated the potential of the connectors are set so that the cathode is at least as negative as the lowest potential of the connectors.

Abstract: A method is described for eliminating abnormalities in a polycrystalline silicon integrated circuit structure, such as a silicon gate field effect transistor structure. The layer of polysilicon is deposited on an insulator coating which may be the thickness of the gate dielectric. The polycrystalline silicon is delineated by lithographic techniques and a reactive ion etching process to form the desired conductor structure which would include gate electrodes for the field effect transistor structure. A thickness of the polycrystalline silicon of the order of hundreds of Angstroms is left upon the insulator coating where the masking layer has openings. This thin coating of polycrystalline silicon in the order of hundreds of Angstroms is then thermally oxidized together with the exposed sidewall of the polycrystalline silicon in the areas under the opaque parts of the masking layer to form silicon dioxide on the sidewall of the polycrystalline silicone structures.