Abstract:
s wird ein Verfahren zur Herstellung eines Halbleiterbauelements mit einem Halbleitertrager (1) vorgeschlagen, bei welchem fur die Ausbildung von frei tragenden Strukturen (3) fur ein Bauelementeine flächige poröse Membranschicht (3) und eine Kavität (2) unter der porösen Membranschicht (3) erzeugt wird. Die Erfindung hat die Aufgabe, eine Membranbeschädigung bei der Herstellung oder bei regelmässig auftrenden Anwendungsfällen zu vermeiden. Diese Aufgabe kann durch unterschiedliche Vorgehensweisen gelöst werden. Bei einer ersten Lösung erhält der Halbleiterträger (1) im Membranbereich im Vergleich zur Kavität eine unterschiedliche Dotierung, womit sich unterschiedliche Porengrössen und/oder Porositäten herstellen lassen, was bei der Kavitätserzeugung fur einen verbesserten Ätzgastransport genutzt werden kann. Die Aufgabe kann jedoch auch dadurch gelöst werden, dass im Membranbereich Mesoporen und im späteren Kavitätsbereich Nanporen als Hilfsstruktur erzeugt werden. Im Weiteren wird unter anderem ein Halbleiterbauelement vorgeschlagen, das auf einem oder mehreren dieser Verfahren basiert.
Abstract:
The invention relates to a micromechanical semiconductor array comprising a membrane (7) formed inside a hollow space (9). The membrane (7) is configured by a crystalline layer inside the substrate (1) or inside an epitaxial layer sequence of the semiconductor array placed inside a substrate (1). The membrane (1) is placed on the edge segment on a support (6) and covered by a covering layer (4) held on a counter-support (5). The support (6), the counter-support (5) and the membrane are all made of materials with different etching rates in relation to a predetermined wet-chemical etching agent and preferably consist of materials with different doping.
Abstract:
A method for providing a conductive ground plane beneath a suspended microstructure. A conductive region is diffused into a substrate. Two dielectric layers are added: first a thermal silicon dioxide layer and then a silicon nitride layer. A first mask is used to etch a ring partially through the silicon nitride layer. Then, a second mask is used to etch a hole through both dielectric layers in a region having a perimeter that extends between the inner and outer edges of the ring. This leaves the conductive region exposed in an area surrounded by a ring that has the silicon dioxide layer and a narrow silicon nitride layer. The ring is surrounded by an area in which the silicon dioxide and silicon nitride layers have not been reduced. A spacer silicon dioxide layer is deposited over the dielectric and then a polysilicon layer is deposited and formed into the shape of a suspended microstructure. When the spacer layer is etched away, the silicon dioxide under the narrow silicon nitride layer is removed, along with the narrow silicon nitride layer, leaving an exposed ground plane surrounded by a dielectric with minimal undercutting.
Abstract:
A process for manufacturing an interaction system of a microelectromechanical type for a storage medium, the interaction system provided with a supporting element and an interaction element carried by the supporting element, envisages the steps of: providing a wafer of semiconductor material having a substrate with a first type of conductivity and a top surface; forming a first interaction region having a second type of conductivity, opposite to the first type of conductivity, in a surface portion of the substrate in the proximity of the top surface; and carrying out an electrochemical etch of the substrate starting from the top surface, the etching being selective with respect to the second type of conductivity, so as to remove the surface portion of the substrate and separate the first interaction region from the substrate, thus forming the supporting element.
Abstract:
A method for manufacturing a micromechanical diaphragm structure having access from the rear of the substrate includes: n-doping at least one contiguous lattice-type area of a p-doped silicon substrate surface; porously etching a substrate area beneath the n-doped lattice structure; producing a cavity in this substrate area beneath the n-doped lattice structure; growing a first monocrystalline silicon epitaxial layer on the n-doped lattice structure; at least one opening in the n-doped lattice structure being dimensioned in such a way that it is not closed by the growing first epitaxial layer but instead forms an access opening to the cavity; an oxide layer being created on the cavity wall; a rear access to the cavity being created, the oxide layer on the cavity wall acting as an etch stop layer; and the oxide layer being removed in the area of the cavity.
Abstract:
Provided is a method for manufacturing a floating structure of a MEMS. The method for manufacturing a floating structure of a microelectromechanical system (MEMS), comprising the steps of: a) forming a sacrificial layer including a thin layer pattern doped with impurities on a substrate; b) forming a support layer on the sacrificial layer; c) forming a structure to be floated on the support layer by using a subsequent process; d) forming an etch hole exposing both side portions of the thin layer pattern; and e) removing the sacrificial layer through the etch hole to form an air gap between the support layer and the substrate.
Abstract:
The invention relates to a method of fabricating and electromechanical device on at least one substrate, the device including at least one active element and wherein the method comprises: a) making a heterogeneous substrate comprising a first portion, an interface layer, and a second portion, the first portion including one or more buried zones sandwiched between first and second regions formed in a first monocrystalline material, the first region extending to the surface of the first portion, and the second region extending to the interface layer, at least one said buried zone being made at least in part out of a second monocrystalline material so as to make it selectively attackable relative to the first and second regions; b) making openings from the surface of the first portion and through the first region, which openings open out to at least one said buried zone; and c) etching at least part of at least one buried zone to form at least one cavity so as to define at least one active element that is at least a portion of the second region between a said cavity and said interface layer; and wherein the first and second portions of the substrate are constituted respectively from first and second substrates that are assembled together by bonding, at least one of them including at least one said interface layer over at least a fraction of its surface.
Abstract:
A wafer for use in a MEMS device having two doped layers surrounding an undoped layer of silicon is described. By providing two doped layers around an undoped core, the stress in the lattice structure of the silicon is reduced as compared to a solidly doped layer. Thus, problems associated with warping and bowing are reduced. The wafer may have a pattered oxide layer to pattern the deep reactive ion etch. A first deep reactive ion etch creates trenches in the layers. The walls of the trenches are doped with boron atoms. A second deep reactive ion etch removes the bottom walls of the trenches. The wafer is separated from the silicon substrate and bonded to at least one glass wafer.
Abstract:
Methods for producing a MEMS device from a single silicon-on-insulator (SOI) wafer. An SOI wafer includes a silicon (Si) handle layer, a Si mechanism layer and an insulator layer located between the Si handle and Si mechanism layers. An example method includes etching active components from the Si mechanism layer. Then, the exposed surfaces of the Si mechanism layer is doped with boron. Next, portions of the insulator layer proximate to the etched active components of the Si mechanism layer are removed and the Si handle layer is etched proximate to the etched active components.
Abstract:
A microelectromechanical systems device having support structures formed of sacrificial material that is selectively diffused with a dopant material or formed of a selectively oxidized metal sacrificial material. The microelectromechanical systems device includes a substrate having an electrode formed thereon. Another electrode is separated from the first electrode by a cavity and forms a movable layer, which is supported by support structures formed of a diffused or oxidized sacrificial material.