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:
The invention relates to the production of a micromechanical component, comprising a substrate (10), made from a substrate material with a first doping type (p), a micromechanical functional structure arranged in the substrate (10) and a cover layer for the at least partial covering of the micromechanical functional structure. The micromechanical functional structure comprises regions (15; 15a; 15b; 15c; 730; 740; 830) made from the substrate material with a second doping type (n), at least partially surrounded by a cavity (50; 50a-f) and the cover layer comprises a porous layer (30) made from the substrate material.
Abstract:
A semiconductor accelerometer is formed by attaching a semiconductor layer to a handle wafer by a thick oxide layer. Accelerometer geometry is patterned in the semiconductor layer, which is then used as a mask to etch out a cavity in the underlying thick oxide. The mask may include one or more apertures, so that a mass region will have corresponding apertures to the underlying oxide layer. The structure resulting from an oxide etch has the intended accelerometer geometry of a large volume mass region supported in cantilever fashion by a plurality of piezo-resistive arm regions to a surrounding, supporting portion of the semiconductor layer. Directly beneath this accelerometer geometry is a flex-accommodating cavity realized by the removal of the underlying oxide layer. The semiconductor layer remains attached to the handle wafer by means of the thick oxide layer that surrounds the accelerometer geometry, and which was adequately masked by the surrounding portion of the top semiconductor layer during the oxide etch step. In a second embodiment support arm regions are dimensioned separately from the mass region, using a plurality of buried oxide regions as semiconductor etch stops.
Abstract:
The invention relates, in particular, to a method for producing subsequent patterns in an underlying layer (120), the method comprising at least a step of producing previous patterns in a printable layer (110) overlying the underlying layer (120), the production of the previous patterns comprising the nanoimprinting of the printable layer (110) and leaving in place a continuous layer formed by the printable layer (110) and covering the underlying layer (120), characterised in that it comprises the following step: at least one step of modifying the underlying layer (120) by ion implantation (421) in the underlying layer (120), the implantation (421) being carried out through the printable layer (110) comprising the subsequent patterns, the implantation (421) parameters being chosen so as to form, in the underlying layer (120), implanted areas (122) and non-implanted areas, the non-implanted areas defining the subsequent patterns and having a geometry that is dependent on the previous patterns.
Abstract:
The invention proposes a particularly simple, cost-effective method for producing a micromechanical membrane structure with access from the rear of the substrate. Said method is based on a p-doped Si substrate (1) and comprises the following process steps: n-doping of at least one continuous lattice-type region (2) of the substrate surface; porous etching of a substrate region (5) below the n-doped lattice structure (2); creation of a cavity (7) in said substrate region (5) below the n-doped lattice structure (2); growing of a first monocrystalline silicon epitaxial layer (8) on the n-doped lattice structure (2). The invention is characterised in that at least one opening (6) in the n-doped lattice structure (2) is dimensioned in such a way that it is not closed by the growing first epitaxial layer (8) and instead forms an access opening (9) to the cavity (7); an oxide layer (10) is created on the cavity wall; A rear face access (13) to the cavity (7) is created, the oxide layer (10) acting as an etch stop layer; and the oxide layer (10) is removed in the region of the cavity (7) producing a rear face access (13) to the membrane structure (14) lying above the cavity (7).
Abstract:
Die Erfindung beschreibt ein Verfahren zur Herstellung eines Halbleiterbauelements, insbesondere eines mikromechanischen Membransensors, sowie ein Halbleiterbauelement nach einem der beanspruchten Herstellungsverfahren, mit einem Halbleiterträger, einer Membran und einer Kaverne.
Abstract:
Die Anmeldung beschreibt ein Herstellungsverfahren eines insbesondere mikromechanischen Halbleiterbauelements sowie ein mit diesem Verfahren hergestelltes Halbleiterbauelement. Zur Herstellung des Halbleiterbauelements ist vorgesehen, dass auf einem Halbleiterträger ein strukturiertes Stabilisierungselement mit wenigstens einer Öffnung erzeugt wird. Die Öffnung ist dabei so angebracht, dass sie den Zugang zu einem mit einer ersten Dotierung aufweisenden ersten Bereich im Halbleiterträger erlaubt. Weiterhin ist ein selektives Herauslösen wenigstens eines Teils des mit der ersten Dotierung versehenen Halbleitermaterials aus dem ersten Bereich des Halbleiterträger vorgesehen. Darüber hinaus wird mittels einer ersten Epitaxieschicht, die auf das Stabilisierungselement aufgebracht wird, eine Membran oberhalb des ersten Bereichs erzeugt. Wenigstens ein Teil des ersten Bereichs dient in einem weiteren Verfahrensschritt dazu, eine Kaverne unterhalb des Stabilisierungselement zu erzeugen. Der Kern der Anmeldung besteht nun darin, das strukturierte Stabilisierungselement mittels einer zweiten Epitaxieschicht, die auf dem Halbleiterträger aufgebracht wird, zu erzeugen.