A method of forming apparatus including a force transducer on a silicon substrate having an upper surface, the silicon substrate including a dopant of one of the n-type or the p-type, the force transducer including a cavity having spaced end walls and a beam supported in the cavity, the beam extending between the end walls of the cavity, the method including the steps of: (a) implanting in the substrate a layer of a dopant of said one of the n-type or the p-type; (b) depositing an epitaxial layer on the upper surface of the substrate, the epitaxial layer including a dopant of the other of the n-type or the p-type; (c) implanting a pair of spaced sinkers through the epitaxial layer and into electrical connection with said layer, each of the sinkers including a dopant of the one of the n-type or the p-type; (d) anodizing the substrate to form porous silicon of the sinkers and the layer; (e) oxidizing the porous silicon to form silicon dioxide; and (f) etching the silicon dioxide to form the cavity and beam.
This is a continuation of application Ser. No. 08/488,146, filed Jun. 7, 1995, entitled "TRANSDUCER HAVING A RESONATING SILICON BEAM AND METHOD FOR FORMING SAME", now abandoned.
A method for manufacturing a minute silicon mechanical device, which includes the steps of forming a diffusion region by doping a predetermined portion of a silicon substrate with an impurity of high density; forming an epitaxial layer over the silicon substrate including the diffusion region and forming an oxide layer over the epitaxial layer; forming an ohmic contact layer at the lower surface of the silicon substrate; patterning the oxide layer to have a striped configuration at that portion of the oxide layer corresponding to the predetermined portion of the diffusion region, thus exposing a predetermined portion of the epitaxial layer; forming a plurality of beams having a striped configuration by etching the exposed portion of the epitaxial layer, using the oxide layer as a mask and then removing the oxide layer; and removing the diffusion region below the plurality of beams.
This invention comprises a process for fabricating a MEMS microstructure in a sealed cavity wherein the etchant entry holes are created as a by-product of the fabrication process without an additional step to etch holes in the cap layer. The process involves extending the layers of sacrificial material past the horizontal boundaries of the cap layer. The cap layer is supported by pillars formed by a deposition in holes etched through the sacrificial layers, and the etchant entry holes are formed when the excess sacrificial material is etched away, leaving voids between the pillars supporting the cap.
A micromechanical component having a substrate made from a substrate material having a first doping type, a micromechanical functional structure provided in the substrate and a cover layer to at least partially cover the micromechanical functional structure. The micromechanical functional structure has zones made from the substrate material having a second doping type, the zones being at least partially surrounded by a cavity, and the cover layer has a porous layer made from the substrate material.
A sensor element provided with a silicon substrate having a semiconductor circuit, a sensing-element portion formed on the silicon substrate and connected to the semiconductor circuit, and a cavity portion formed by removing a silicon substrate portion below the sensing-element portion, in which a removal resistance region having resistance against substrate removal is provided in the silicon substrate between the semiconductor circuit and the cavity portion.
A method is for producing a semiconductor component, e.g., a multilayer semiconductor element, e.g., a micromechanical component, e.g., a pressure sensor, having a semiconductor substrate, e.g., made of silicon, and a semiconductor component produced according to the method. To reduce the production cost of such a semiconductor component, in a first step a first porous layer is produced in the semiconductor component, and in a second step a hollow or cavity is produced under or from the first porous layer in the semiconductor component, with the hollow or cavity capable of being provided with an external access opening.
