Abstract:
The invention relates to a micromechanical device comprising a semiconductor element capable of deflecting or resonating and comprising at least two regions having different material properties and drive or sense means functionally coupled to said semiconductor element. According to the invention, at least one of said regions comprises one or more n-type doping agents, and the relative volumes, doping concentrations, doping agents and/or crystal orientations of the regions being configured so that the temperature sensitivities of the generalized stiffness are opposite in sign at least at one temperature for the regions, and the overall temperature drift of the generalized stiffness of the semiconductor element is 50 ppm or less on a temperature range of 100°C. The device can be a resonator. Also a method of designing the device is disclosed.
Abstract:
A method of adjusting the position of a micro-mechanical bi-material cantilever is provided. The bi-material includes a first and a second material and each material has a corresponding thermal expansion coefficient. The method includes implanting ions predominantly into one material of the bi-material to modify internal stress in one of the first and second materials relative to the other material. The deformation of the bi-material is then detected to modulate the implantation of ions thereto.
Abstract:
A micro-electro-mechanical (MEM) device and an electronic device are fabricated on a common substrate by fabricating the electronic device comprising a plurality of electronic components on the common substrate, depositing a thermally stable interconnect layer on the electronic device, encapsulating the interconnected electronic device with a protective layer, forming a sacrificial layer over the protective layer, opening holes in the sacrificial layer and the protective layer to allow the connection of the MEM device to the electronic device, fabricating the MEM device by depositing and patterning at least one layer of amorphous silicon, and removing at least a portion of the sacrificial layer. In this way, the MEM device can be fabricated after the electronic device on the same substrate.
Abstract:
Verfahren zur Erzeugung einer Siliziummembran mit vorbestimmten Spannungseigenschaften. Ein Siliziumsubstrat wird dotiert, um eine dotierte Schicht zu bilden, deren Dicke mit der Dicke der Membran genau übereinstimmt. Die Spannung in der dotierten Schicht wird durch Auswählen der Dotierungssubstanz unter Zugrundelegung ihres atomaren Durchmessers im Verhältnis zu Silizium sowie durch Steuern der Gesamtkonzentration und des Konzentrationsprofils der Dotierungssubstanz kontrolliert. Danach wird die Membran durch elektrochemisches Wegätzen des Substrats unterhalb der dotierten Schicht gebildet.
Abstract:
Method and apparatus of to obtain as-deposited polycrystalline and low-stress SiGe layers. These layers are used in Micro Electro-Mechanical Systems (MEMS) devices or micromachined structures. Different parameters are analysed which effect the stress in a polycrystalline layer. The parameters include, without limitation: deposition temperature; concentration of semiconductors (e.g., the concentration of Silicon and Germanium in a SixGe1-x layer, with x being the concentration parameter); concentration of dopants (e.g., the concentration of Boron or Phosphorous); amount of pressure; and use of plasma. Depending on the particular environment in which the polycrystalline SiGe is grown, different values of parameters are used.
Abstract:
A MEMS microphone includes a substrate having a cavity, a diaphragm disposed above the cavity and having a ventilation path, and a back plate disposed above the diaphragm and having a plurality of air holes. The ventilation path includes a plurality of slits extending in a circumferential direction.
Abstract:
A method of manufacturing a resonant transducer having a vibration beam includes: (a) providing an SOI substrate including: a first silicon layer; a silicon oxide layer on the first silicon layer; and a second silicon layer on the silicon oxide layer; (b) forming a first gap and second gap through the second silicon layer by etching the second silicon layer using the silicon oxide layer as an etching stop layer; (c) forming an impurity diffusion source layer on the second silicon layer; (d) forming an impurity diffused layer in a surface portion of the second silicon layer; (e) removing the impurity diffusion source layer through etching; and (f) removing at least a portion of the silicon oxide layer through etching such that an air gap is formed between the first silicon layer and a region of the second silicon layer surrounded by the first and second gaps.