Abstract: Manufacturing a semiconductor device involves forming (200) a sacrificial layer where a micro cavity is to be located, forming (210) a metal layer of thickness greater than 1 micron over the sacrificial layer, forming (220) a porous layer from the metal layer, the porous layer having pores of length greater than ten times their breadth, and having a breadth in the range 10 nm-500 nanometers. The pores can be created by anodising, electrodeposition or dealloying. Then the sacrificial layer can be removed (230) through the porous layer, to form the micro cavity, and pores can be sealed (240). Encapsulating MEMS devices with a porous layer can reduce costs by avoiding using photolithography for shaping the access holes since the sacrificial layer is removed through the porous membrane.

Abstract: The present invention provides a method for manufacturing micromachined devices on a substrate (10) comprising electrical circuitry, the micromachined devices comprising at least one micromachined structure, without affecting the underlying electrical circuitry. The method comprises providing a protection layer (15) on the substrate (10); providing on the protection layer (15) a plurality of patterned layers for forming the at least one micromachined structure, the plurality of patterned layers comprising at least one sacrificial layer (18); and thereafter removing at least a portion of the sacrificial layer (18) to release the at least one micromachined structure. The method furthermore comprises, before providing the protection layer (15), annealing the substrate (10) at a temperature higher than a highest temperature used during manufacturing of the micromachined device, annealing being for preventing gas formation underneath the protection layer (15) during subsequent manufacturing steps.

Abstract: A method is provided 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. The process parameters of the depositing and/or annealing steps 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. Structural silicon germanium layers for surface micromachined structures can be formed at temperatures substantially below 400° C., which offers the possibility of post-processing micromachined structures on top of a substrate comprising electronic circuitry such as CMOS circuitry.

Abstract: A method of depositing a structural SiGe layer is presented. The structural SiGe layer may be located on top of a sacrificial layer above a substrate. The substrate may contain a semiconductor device such as a CMOS electronic circuit. The presented method uses a silicon source and a germanium source in a reaction zone to grow the structural SiGe layer. Hydrogen is introduced into the reaction zone and it may be used to dilute the silicon source and the germanium source. The resultant reaction occurs at temperatures below 450 degrees C., thereby preventing degradation of electronic device and/or other devices/materials located in the substrate.

Abstract: Manufacturing a semiconductor device involves forming (200) a sacrificial layer where a micro cavity is to be located, forming (210) a metal layer of thickness greater than 1 micron over the sacrificial layer, forming (220) a porous layer from the metal layer, the porous layer having pores of length greater than ten times their breadth, and having a breadth in the range 10 nm-500 nanometers. The pores can be created by anodising, electrodeposition or dealloying. Then the sacrificial layer can be removed (230) through the porous layer, to form the micro cavity, and pores can be sealed (240). Encapsulating MEMS devices with a porous layer can reduce costs by avoiding using photolithography for shaping the access holes since the sacrificial layer is removed through the porous membrane.

Abstract: One inventive aspect relates to a method for forming hermetically sealed cavities, e.g. semiconductor cavities comprising fragile devices, MEMS or NEMS devices. The method allows forming hermetically sealed cavities at a controlled atmosphere and pressure and at low temperatures, for example, at temperatures not exceeding about 200° C. The method further allows forming sealed cavities with short release times, for example, release times of about a few minutes to 30 minutes. The method may, for example, be used for zero level packaging of MEMS or NEMS devices.

Abstract: A method is described for closing openings in a film, for example, in microelectronic process technology, whereby substantially no deposition material passes through the openings, which can be important if fragile micro devices are positioned under the openings. The closure of these openings can cause an underlying cavity to be hermetically sealed, in which an object can be located. In particular the method provides a way for hermetically sealing cavities under controlled atmosphere and pressure in the encapsulation and sealing processes of cavities comprising fragile content. The cavities may comprise for example Micro Electro Mechanical Systems (MEMS).

Abstract: Method and apparatus to obtain as-deposited polycrystalline and low-stress SiGe layers. These layers may be 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 may be used.

Abstract: A method of depositing a structural SiGe layer is presented. The structural SiGe layer may be located on top of a sacrificial layer above a substrate. The substrate may contain a semiconductor device such as a CMOS electronic circuit. The presented method uses a silicon source and a germanium source in a reaction zone to grow the structural SiGe layer. Hydrogen is introduced into the reaction zone and it may be used to dilute the silicon source and the germanium source. The resultant reaction occurs at temperatures below 450 degrees C, thereby preventing degradation of electronic device and/or other devices/materials located in the substrate.

Abstract: The invention relates to methods for preparing as-deposited, low-stress and low resistivity polycrystalline silicon-germanium layers and semiconductor devices utilizing the silicon-germanium layers. These layers can be used in Micro Electro-Mechanical Systems (MEMS) devices or micro-machined structures.

Abstract: A method is described for closing openings in a film, for example, in microelectronic process technology, whereby substantially no deposition material passes through the openings, which can be important if fragile micro devices are positioned under the openings. The closure of these openings can cause an underlying cavity to be hermetically sealed, in which an object can be located. In particular the method provides a way for hermetically sealing cavities under controlled atmosphere and pressure in the encapsulation and sealing processes of cavities comprising fragile content. The cavities may comprise for example Micro Electro Mechanical Systems (MEMS).

Abstract: The present invention is related to a method for producing micromachined devices for use in Microelectromechanical Systems (MEMS), comprising the steps of providing a crystalline wafer, and processing from said wafer at least one micromachined device comprising at least one elongated opening and/or cavity, having a longitudinal axis, so that said longitudinal axis is at an angle to a direction which lies along the intersection of the front plane of the wafer and a cleavage plane, said cleavage plane being defined as a plane along which cleavage of the wafer is most likely to occur.

Abstract: Method and apparatus to obtain as-deposited polycrystalline and low-stress SiGe layers. These layers may be 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 may be used.

Abstract: The present invention is related to a method for producing micromachined devices for use in Microelectromechanical Systems (MEMS), comprising the steps of providing a crystalline wafer, and processing from said wafer at least one micromachined device comprising at least one elongated opening and/or cavity, having a longitudinal axis, so that said longitudinal axis is at an angle to a direction which lies along the intersection of the front plane of the wafer and a cleavage plane, said cleavage plane being defined as a plane along which cleavage of the wafer is most likely to occur.