A method for forming a trench in a first semiconductor layer of a multi-layer system. The method includes: applying a mask layer onto the first semiconductor layer, a recess being formed in the mask layer so that the first semiconductor layer is exposed within the recess; applying a protective layer which completely covers or modifies the first semiconductor layer exposed within the recess; applying a second semiconductor layer; etching the second semiconductor layer to completely remove it in a subarea surrounding the recess of the mask layer; etching the protective layer so that the first semiconductor layer is exposed within the recess; and forming the trench in the first semiconductor layer, the recess of the mask layer serving as an etching mask, and the trench being formed by a cyclical alternation between etching and passivation steps, the first etching step being longer than the subsequent etching steps.

The invention includes a method of promoting interfacial mechanical bonding of two or more components through the use of suspended and/or freestanding structures fabricated using an atom-scale assembly process on at least a portion of the surfaces of such components.

There is provided a method for forming a composite cavity and a composite cavity formed using the method. The method comprises the following steps: providing a silicon substrate (101); forming an oxide layer on the front side thereof; patterning the oxide layer to form one or more grooves (103), the position of the groove (103) corresponding to the position of small cavity (109) to be formed; providing a bonding wafer (104), which is bonded to the patterned oxide layer to form one or more closed micro-cavity structures (105) between the silicon substrate (101) and the bonding wafer (104); forming a protective film (106) over the bonding wafer (104) and forming a masking layer (107) on the back side of the silicon substrate (101); patterning the masking layer (107), the pattern of the masking layer (107) corresponding to the position of a large cavity (108) to be formed; using the masking layer (107) as a mask, etching the silicon substrate (101) from the back side until the oxide layer at the front side thereof to form the large cavity (108) in the silicon substrate (101); and using the masking layer (107) and the oxide layer as a mask, etching the bonding wafer (104) from the back side through the silicon substrate (101) until the protective film (106) thereover to form one or more small cavities (109) in the bonding wafer (104). The uniformity of thickness of the semiconductor medium layer where the small cavity (109) in the composite cavity is located is well controlled by the present invention.

A micromechanical device that includes a first substrate, at least one first cavity, and a sealed inlet to the first cavity, the inlet extending through the first substrate. The inlet includes a laser-drilled first subsection and a plasma-etched second subsection, the plasma-etched second subsection having an opening to the first cavity, and the inlet in the first subsection being sealed by a molten seal made of molten mass of at least the first substrate. A combined laser drilling and plasma etching method for manufacturing micromechanical devices is also described.

A method for forming a micro-electro-mechanical system (MEMS) device structure is provided. The method includes forming a second substrate over a first substrate, and a cavity is formed between the first substrate and the second substrate. The method includes forming a hole through the second substrate using an etching process, and the hole is connected to the cavity. The etching process includes a plurality of etching cycles, and each of the etching cycles includes an etching step, and the etching step has a first stage and a second stage. The etching time of each of the etching steps during the second stage is gradually increased as the number of etching cycles is increased.

In described examples, a hermetic package of a microelectromechanical system (MEMS) structure includes a substrate having a surface with a MEMS structure of a first height. The substrate is hermetically sealed to a cap forming a cavity over the MEMS structure. The cap is attached to the substrate surface by a vertical stack of metal layers adhering to the substrate surface and to the cap. The stack has a continuous outline surrounding the MEMS structure while spaced from the MEMS structure by a distance. The stack has: a first bottom metal seed film adhering to the substrate and a second bottom metal seed film adhering to the first bottom metal seed film; and a first top metal seed film adhering to the cap and a second top metal seed film adhering to the first top metal seed film.

A method of manufacturing a plurality of through-holes in a layer of first material, for example for the manufacturing of a probe comprising a tip containing a channel. To manufacture the through-holes in a batch process, a layer of first material is deposited on a wafer comprising a plurality of pits a second layer is provided on the layer of first material, and the second layer is provided with a plurality of holes at central locations of the pits; using the second layer as a shadow mask when depositing a third layer at an angle, covering a part of the first material with said third material at the central locations, and etching the exposed parts of the first layer using the third layer as a protective layer.

Disclosed are methods and devices relating to microelectromechanical systems (MEMS). A method for fabricating a mechanical beam in a microelectromechanical (MEM) device may comprise depositing a masking layer on a first side of a substrate; etching a first notch on the first side of the substrate; forming a beam structure on the substrate, wherein a first portion of the beam structure is coupled to the first notch; etching a second notch at a second portion of the beam structure; depositing an oxide layer on the beam structure, the masking layer, and the substrate; etching a horizontal surface of the oxide layer at the masking layer and the substrate; and releasing the mechanical beam from the substrate, wherein the mechanical beam comprises the beam structure, the oxide layer, and the masking layer.

A microfluidic chip and a fabrication method of the microfluidic chip are provided. The microfluidic chip includes an array substrate, and a hydrophobic layer disposed on a side of the array substrate. The hydrophobic layer includes at least one through-hole, and a through-hole of the at least one through-hole penetrates through the hydrophobic layer along a direction perpendicular to a plane of the array substrate. The microfluidic chip also includes at least one hydrophilic structure. A hydrophilic structure of the at least one hydrophilic structure is disposed in the through-hole.

A roughened silicon surface is formed by a process including repetitively performed roughening cycles. Each roughening cycles including a step for depositing a non-planar polymeric layer over an area of a silicon body and a step for plasma etching the polymeric layer and the area of the silicon body etch in a non-unidirectional way. As a result, a surface portion of the silicon body is removed, in a non-uniform way, to a depth not greater than 10 nm.