Abstract:
In one embodiment, a method of forming a MEMS device includes providing a substrate, forming a sacrificial layer above the substrate layer, forming a silicon based working portion on the sacrificial layer, releasing the silicon based working portion from the sacrificial layer such that the working portion includes at least one exposed outer surface, forming a first layer of silicide forming metal on the at least one exposed outer surface of the silicon based working portion, and forming a first silicide layer with the first layer of silicide forming metal.
Abstract:
The present invention provides a method for controlling the average stress and the strain gradient in structural silicon germanium layers as used in micromachined devices. The method comprises depositing a single silicon germanium layer on a substrate and annealing a predetermined part of the deposited silicon germanium layer, whereby the process parameters of the depositing step and/or the annealing step are selected such that a predetermined average stress and a predetermined strain gradient are obtained in the predetermined part of the silicon germanium layer. Preferably a plasma assisted deposition technique is used for depositing the silicon germanium layer, and a pulsed excimer laser is used for local annealing, with a limited thermal penetration depth. The present invention provides a method for forming structural silicon germanium layers for surface micromachined structures at temperatures substantially below 400°C, which offers for example the possibility of post-processing micromachined structures on top of a substrate comprising electronic circuitry such as CMOS circuitry, without affecting the functionality and reliability of the electronic circuitry. More in particular, the present invention provides a method for forming structural silicon germanium layers at temperatures not exceeding 210°C, which allows the integration of silicon germanium based micromachined structures on substrates such as polymer films.
Abstract:
A method of forming an electromechanical transducer device (200) comprises forming (500) on a fixed structure (210) a movable structure (203) and an actuating structure of the electromechanical transducer device, wherein the movable structure (203) is arranged in operation of the electromechanical transducer device (200) to be movable in relation to the fixed structure in response to actuation of the actuating structure. The method further comprises providing (504) a stress trimming layer (216) on at least part of the movable structure (203), after providing the stress trimming layer (216), releasing (506) the movable structure (203) from the fixed structure (210) to provide a released electromechanical transducer device (200), and after releasing the movable structure (203), changing (508) stress in the stress trimming layer of the released electromechanical transducer device such that the movable structure (203) is deflected a predetermined amount relative to the fixed structure (210) when the electromechanical transducer device (200) is in an off state.
Abstract:
A mechanism for reducing stiction in a MEMS device by decreasing an amount of carbon from TEOS-based silicon oxide films that can accumulate on polysilicon surfaces during fabrication is provided. A carbon barrier material film (510, 520) is deposited between one or more polysilicon layer (210, 230) in a MEMS device and the TEOS-based silicon oxide layer (220). This barrier material blocks diffusion of carbon into the polysilicon, thereby reducing accumulation of carbon on the polysilicon surfaces. By reducing the accumulation of carbon, the opportunity for stiction due to the presence of the carbon is similarly reduced.
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.