Abstract:
The invention relates to a micromechanical sensor and to a corresponding production method that includes the following steps: a) preparing a doped semiconductor wafer; b) applying an epitaxial layer that is doped in such a way that a jump in the charge carrier density in the interface between the semiconductor wafer and the epitaxial layer occurs; c) optionally etching ventilation holes traversing the epitaxial layer and optionally filling the ventilation holes with a sacrificial material; d) depositing at least one sacrificial layer, at least one spacing layer, a membrane and optionally a semiconductor circuit on the top side of the epitaxial layer using a technology known per se, wherein the semiconductor circuit may be applied after the membrane is formed or while depositing the layers required to form the membrane; e) etching a hole on the back part of the sensor, wherein the etching method is selected in such a way that etching advances in the direction of the top side and ceases in the interference between the wafer and the epitaxial layer by changing charge carrier concentration. The invention also relates to the utilization of the micromechanical sensor in pressure sensors or microphones.
Abstract:
Efficient methods for lithographically fabricating spring structures onto a substrate containing contact pads or metal vias by forming both the spring metal and release material layers using a single mask. Specifically, a pad of release material is self-aligned to the spring metal finger using a photoresist mask or a plated metal pattern, or using lift-off processing techniques. A release mask is then used to release the spring metal finger while retaining a portion of the release material that secures the anchor portion of the spring metal finger to the substrate. When the release material is electrically conductive (e.g., titanium), this release material portion is positioned directly over the contact pad or metal via, and acts as a conduit to the spring metal finger in the completed spring structure. When the release material is non-conductive, a metal strap is formed to connect the spring metal finger to the contact pad or metal via, and also to further anchor the spring metal finger to the substrate.
Abstract:
A dissolved wafer micromachining process is modified by providing an etch control seal around the perimeter of a heavily doped micromechanical structure formed on a substrate. The micromechanical structure is fabricated on a wafer using conventional methods including the formation of a trench that surrounds and defines the shape of the micromechanical structure in the substrate. The etch control seal comprises a portion of the substrate in the form of a raised ring extending around the perimeter of the micromechanical structure and its defining trench. Selected raised areas of the heavily doped micromechanical structure and the top of the raised etch control seal are bonded to a second substrate. A selective etch is then used to dissolve the first substrate so that the heavily doped micromechanical structure remains attached to the second substrate only at the bonded areas. The etch control seal reduces exposure of the micromechanical structure and bonded areas to the etch by preventing the etch from contacting the heavily doped structure until the etch leaks through the dissolving floor of the trench. This occurs only during the final stages of the substrate dissolution step, thus minimizing exposure of the micromechanical structure and bonded areas to the damaging effects of the etch. Use of an etch control seal increases design flexibility and improves micromechanical device yield and quality in a dissolved wafer fabrication process.
Abstract:
The invention relates to a micromechanical sensor and to a corresponding production method, comprising the following steps: a) preparing a doped semiconductor wafer (4); b) applying an epitaxial layer (1) that is doped in such a way that a jump in the charge carrier density in the interface (11) between the semiconductor wafer and the epitaxial layer occurs; c) optionally etching ventilation holes (2) traversing the epitaxial layer and optionally filling the ventilation holes with a sacrificial material; d) depositing at least one sacrificial layer (9), at least one spacing layer (10), a membrane (5) and optionally a semiconductor circuit (8) on the top side of the epitaxial layer using a technology known per se, wherein the semiconductor circuit may be applied after the membrane is formed or while depositing the layers required to form the membrane; e) etching a hole (6) on the back part of the sensor, wherein the etching method is selected in such a way that etching advances in the direction of the top side and ceases in the interface between the wafer (4) and the epitaxial layer (1) by changing charge carrier concentration. The invention also relates to the utilization of the micromechanical sensor in pressure sensors or microphones.
Abstract:
L'invention est relative à un procédé de fabrication d'un dispositif électromécanique sur au moins un substrat comprenant au moins un élément actif caractérisé en ce qu'il comporte : a) la réalisation d'un substrat hétérogène comprenant une première partie (1, 3, 6), une couche d'interface (8) et une seconde partie (9), la première partie (1, 3, 6) comportant une ou plusieurs zones enterrées (2 1 , 3 1 , 5 1 , 51) en sandwich entre une première (1), et une deuxième (6) région réalisées dans un premier matériau monocristallin, la première région (1) s'étendant jusqu'à la surface (1') de la première partie, et la deuxième région (6) s'étendant jusqu'à la couche d'interface (8, 8'), au moins une dite zone enterrée (2 1 , 3 1 , 5 1 , 51) étant au moins en partie dans un deuxième matériau monocristallin de manière à la rendre sélectivement attaquable par rapport à la première (1) et la deuxième (6) région ; b) la réalisation depuis la surface (1") de la première partie et à travers ladite première région (1) d'ouvertures (20) débouchant sur au moins une dite zone enterrée (2 1 , 3 1 , 5 1 , 51) ; c) la gravure au moins partielle d'au moins une zone enterrée (2 1 , 3 1 , 5 1 , 51) pour former au moins une cavité (14), de manière à définir au moins un élément actif qui est au moins une partie de la deuxième région (6) entre une dite cavité (14) et ladite couche d'interface (8, 8') ;
caractérisé en ce que les première (1, 3, 6) et seconde (9) parties du substrat sont constituées respectivement d'un premier et d'un deuxième substrats assemblés par collage dont l'un au moins porte au moins sur une partie de sa surface, une dite couche d'interface (8).
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:
Efficient methods for lithographically fabricating spring structures onto a substrate (301) containing contact pads or metal vias (305) by forming both the spring metal and release material layers using a single mask. Specifically, a pad of release material (310) is self-aligned to the spring metal finger (320) using a photoresist mask or a plated metal pattern, or using lift-off processing techniques. A release mask is then used to release the spring metal finger while retaining a portion of the release material that secures the anchor portion of the spring metal finger to the substrate. When the release material is electrically conductive (e.g., titanium), this release material portion is positioned directly over the contact pad or metal via, and acts as a conduit to the spring metal finger in the completed spring structure. When the release material is non-conductive, a metal strap is formed to connect the spring metal finger to the contact pad or metal via, and also to further anchor the spring metal finger to the substrate.
Abstract:
Die Erfindung betrifft ein Verfahren zum Herstellen von räumlich strukturierten Bauteilen 10 aus einem Körper 1, bei dem auf der Rückseite des Körpers 1 eine Verzögerungsschicht 8 mit Durchbrechungen 9 zum Verzögern eines Abtragvorgangs des Materials des Körpers vorgesehen wird, auf der Rückseite des Körpers 1 Gebiete 5 aus einem migrationsfähigen Material aufgebracht werden, der Körper 1 einem thermischen Migrationsverfahren unterzogen wird, so daß Migrationsbereiche 7 entstehen, und dann die Bauteile 10 in einem einzigen Abtragvorgang aus dem Körper 1 herausgetrennt und die Migrationsbereiche 7 freigelegt werden.