Abstract:
A method for fabricating a thermally isolated microelectromechanical system (MEMS) structure is provided. The method includes processing a first wafer of a first material with a glass wafer to form a composite substrate including at least one sacrificial structure of the first material and glass; forming a MEMS device in a second material; forming at least one temperature sensing element on at least one of: the composite substrate; and the MEMS device; and etching away the at least one sacrificial structure of the first material in the composite substrate to form at least one thermally isolating glass flexure. The MEMS device is thermally isolated on a thermal isolation stage by the at least one thermally isolating glass flexure. The at least one temperature sensing element in on a respective at least one of: the thermal isolation stage; and the MEMS device.
Abstract:
A device/method for sensing a physical parameter, including a sensor die and a stress-sensitive circuit. The sensor die includes a semiconductor substrate and a cavity that creates an elastic element that bends in response to the physical parameter exerted on the sensor die. The elastic element includes at least at least one rigid island formed within the cavity, a thin area surrounding the at least one rigid island and having smaller thickness than the rigid island, and at least one stress concentrator at least partially formed in the thin area of the elastic element on the side of the substrate opposite the cavity. The stress-sensitive circuit includes at least one stress-sensitive component formed in the thin area of the elastic element. The at least one stress concentrator increases stress in the locations of the at least one stress-sensitive component resulting in an increase of the device sensitivity to the physical parameter.
Abstract:
In one embodiment, the process flow for a capacitive pressures sensor is combined with the process flow for an inertial sensor. In this way, an inertial sensor is realized within the membrane layer of the pressure sensor. The device layer is simultaneously used as z-axis electrode for out-of-plane sensing in the inertial sensor, and/or as the wiring layer for the inertial sensor. The membrane layer (or cap layer) of the pressure sensor process flow is used to define the inertial sensor sensing structures. Insulating nitride plugs in the membrane layer are used to electrically decouple the various sensing structures for a multi-axis inertial sensor, allowing for fully differential sensing.
Abstract:
Capteur inertielle comportant une partie fixe (8) et au moins une masse suspendue (6) par rapport à la partie fixe (8) et des moyens d'amortissement (4) du déplacement de la partie suspendue (6) par rapport à la partie fixe (8), lesdits moyens d'amortissement (4) étant des moyens d'amortissement électromécaniques comportant une source d'alimentation continue (14), une résistance électrique (R) et un condensateur à capacité variable (C) en série, ledit condensateur à capacité variable (C) étant formé en partie par la partie suspendue (6) et en partie par la partie fixe (8) de sorte qu'un déplacement de la partie suspendue(6) provoque une variation de capacité du condensateur à capacité variable (C).
Abstract:
Systems and methods for mounting inertial sensors on a board 64. On a wafer containing one or more sensor packages having a substrate layer 32, 34, a sensor layer 24 and an insulator layer 26, 28 located between the sensor layer and the substrate layer, a V-groove is anisotropically etched into one of the substrate layer. The substrate layer is in the 100 crystal plane orientation. The sensor package is then separated from the wafer. Then, a surface of the substrate layer formed by the etching is attached to a board. In one example, three sensor packages are mounted to the board so that their sense axis are perpendicular to each other.
Abstract:
In order to provide a technology capable of suppressing degradation of measurement accuracy due to fluctuation of detection sensitivity of an MEMS by suppressing fluctuation in natural frequency of the MEMS caused by a stress, first, fixed portions 3a to 3d are displaced outward in a y-direction of a semiconductor substrate 2 by deformation of the semiconductor substrate 2. Since a movable body 5 is disposed in a state of floating above the semiconductor substrate 2, it is not affected and displaced by the deformation of the semiconductor substrate 2. Therefore, a tensile stress (+σ 1 ) occurs in the beam 4a and a compressive stress (-σ 2 ) occurs in the beam 4b. At this time, in terms of a spring system made by combining the beam 4a and the beam 4b, increase in spring constant due to the tensile stress acting on the beam 4a and decrease in spring constant due to the compressive stress acting on the beam 4b are offset against each other.
Abstract:
A method of manufacturing an external force detection sensor in which a sensor element is formed by through-hole (20) dry etching of an element substrate (3), and an electrically conductive material is used as an etching stop layer (18) during the dry etching.
Abstract:
A process for manufacturing a suspended structure (20) of semiconductor material envisages the steps of: providing a monolithic body (10) of semiconductor material having a front face (10a); forming a buried cavity (17) within the monolithic body (10), extending at a distance from the front face (10a) and delimiting, with the front face (10a), a surface region (18) of the monolithic body (10), said surface region (18) having a first thickness (w 1 ); carrying out a thickening thermal treatment such as to cause a migration of semiconductor material of the monolithic body (10) towards the surface region (18) and thus form a suspended structure (20) above the buried cavity (17), the suspended structure (20) having a second thickness (w 2 ) greater than the first thickness (w 1 ). The thickening thermal treatment is an annealing treatment.