Abstract:
Disclosed are one-port and two-port microelectromechanical structures including variable capacitors, switches, and filter devices. High aspect-ratio micromachining is used to implement low-voltage, large value tunable and fixed capacitors, and the like. Tunable capacitors can move in the plane of the substrate by the application of DC voltages and achieve greater than 240 percent of tuning. Exemplary microelectromechanical apparatus comprises a single crystalline silicon substrate, and a conductive structure laterally separated from the single crystalline silicon substrate by first and second high aspect ratio gaps of different size, wherein at least one of the high aspect ratio gaps has an aspect ratio of at least 30:1, and is vertically anchored to the single crystalline silicon substrate by way of silicon nitride.
Abstract:
An etching method and an etching system are adapted to produce a high etch selectivity for a mask, an excellent anisotropic profile and a large etching depth. An etching system according to the invention comprises a floating electrode arranged vis-à-vis a substrate electrode in a vacuum chamber and held in a floating state in terms of electric potential, a material arranged at the side of the floating electrode facing the substrate electrode to form an anti-etching film and a control unit for intermittently applying high frequency power to the floating electrode. An etching method according to the invention uses a material arranged at the side of the floating electrode opposite to the substrate electrode to form an anti-etching film as target and only rare gas as main gas and is adapted to repeat a step of forming a film on the substrate by sputtering by applying high frequency power to the floating electrode and a step of subsequently etching the substrate by suspending the application of high frequency power to the floating electrode and introducing etching gas into the vacuum chamber in a predetermined sequence (FIG. 1).
Abstract:
The invention relates to a method of making a component from a heterogeneous substrate comprising first and second portions in at least one monocrystalline material, and a sacrificial layer constituted by at least one stack of at least one layer of monocrystalline Si situated between two layers of monocrystalline SiGe, the stack being disposed between said first and second portions of monocrystalline material, wherein the method consists in etching said stack by making: e) at least one opening in the first and/or second portion and the first and/or second layer of SiGe so as to reach the layer of Si; and f) eliminating all or part of the layer of Si.
Abstract:
A method for fabricating a MEMS device having a fixing part fixed to a substrate, a connecting part, a driving part, a driving electrode, and contact parts, includes patterning the driving electrode on the substrate; forming an insulation layer on the substrate; patterning the insulation layer and etching a fixing region and a contact region of the insulation layer; forming a metal layer over the substrate; planarizing the metal layer until the insulation layer is exposed; forming a sacrificial layer on the substrate; patterning the sacrificial layer to form an opening exposing a portion of the insulation layer and the metal layer in the fixing region; forming a MEMS structure layer on the sacrificial layer to partially fill the opening, thereby forming sidewalls therein; and selectively removing a portion of the sacrificial layer by etching so that a portion of the sacrificial layer remains in the fixing region.
Abstract:
A released beam structure fabricated in trench and manufacturing method thereof are provided herein. One embodiment of a released beam structure according to the present invention comprises a semiconductor substrate, a trench, a first conducting layer, and a beam. The trench extends into the semiconductor substrate and has walls. The first conducting layer is positioned over the walls of the trench at selected locations. The beam is positioned with the trench and is connected at a first portion thereof to the semiconductor substrate and movable at a second portion thereof. The second portion of the beam is spaced from the walls of the trench by a selected distance. Therefore, the second portion of the beam is free to move in a plane that is perpendicular or parallel to the surface of the substrate, and could be deflected to electrically contact with the walls of the trench in response to a predetermined acceleration force or a predetermined temperature variation applied on the beam structure. Other beam structures such as a beam held at both ends, or a beam held in the middle are also possible. Several beam structures at different angles can be fabricated simultaneously and mechanical etching stops are automatically formed to prevent unwanted overstress conditions when manufacturing several beam structures at the same time. Beam structures can also be manufactured in three orthogonal directions, providing information on acceleration in any direction.
Abstract:
A microelectromechanical systems (MEMS) device utilizing an aluminum fluoride layer as an etch stop is disclosed. In one embodiment, a MEMS device includes a first electrode having a first surface; and a second electrode having a second surface facing the first surface and defining a gap therebetween. The second electrode is movable in the gap between a first position and a second position. At least one of the electrodes includes an aluminum fluoride layer facing the other of the electrodes. During fabrication of the MEMS device, a sacrificial layer is formed between the first and second electrodes and is released to define the gap. The aluminum fluoride layer serves as an etch stop to protect the first or second electrode during the release of the sacrificial layer.
Abstract:
The fabrication of a MEMS device such as an interferometric modulator is improved by employing an etch stop layer between a sacrificial layer and a an electrode. The etch stop may reduce undesirable over-etching of the sacrificial layer and the electrode. The etch stop layer may also serve as a barrier layer, buffer layer, and or template layer. The etch stop layer may include silicon-rich silicon nitride.
Abstract:
In a method for manufacturing a micromechanical semiconductor component, e.g., a pressure sensor, a locally limited, buried, and at least partially oxidized porous layer is produced in a semiconductor substrate. A cavity is subsequently produced in the semiconductor substrate from the back, directly underneath the porous first layer, using a trench etch process. The porous first layer is used as a stop layer for the trench. Thin diaphragms having a low thickness tolerance may thus be produced for differential pressure measurement.
Abstract:
Micro-electromechanical systems (MEMS) pre-fabrication products and methods for forming MEMS devices using silicon-on-metal (SOM) wafers. An embodiment of a method may include the steps of bonding a patterned SOM wafer to a cover wafer, thinning the handle layer of the SOM wafer, selectively removing the exposed metal layer, and either continuing with final metallization or cover bonding to the back of the active layer.
Abstract:
An etching method and an etching system are adapted to produce a high etch selectivity for a mask, an excellent anisotropic profile and a large etching depth. An etching system according to the invention comprises a floating electrode arranged vis-à-vis a substrate electrode in a vacuum chamber and held in a floating state in terms of electric potential, a material arranged at the side of the floating electrode facing the substrate electrode to form an anti-etching film and a control unit for intermittently applying high frequency power to the floating electrode. An etching method according to the invention uses a material arranged at the side of the floating electrode opposite to the substrate electrode to form an anti-etching film as target and only rare gas as main gas and is adapted to repeat a step of forming a film on the substrate by sputtering by applying high frequency power to the floating electrode and a step of subsequently etching the substrate by suspending the application of high frequency power to the floating electrode and introducing etching gas into the vacuum chamber in a predetermined sequence (FIG. 1).