Abstract:
A method of forming buried cavities in a wafer of monocrystalline semiconductor material with at least one cavity formed in a substrate of monocrystalline semiconductor material by timed TMAH etching silicon; covering the cavity with a material inhibiting epitaxial growth; and growing a monocrystalline epitaxial layer above the substrate and the cavities. Thereby, the cavity is completely surrounded by monocrystalline material. Starting from this wafer, it is possible to form a thin membrane. The original wafer must have a plurality of elongate cavities or channels, parallel and adjacent to one another. Trenches are then excavated in the epitaxial layer as far as the channels, and the dividers between the channels are removed by timed TMAH etching.
Abstract:
For manufacturing an SOI substrate, the following steps are carried out: providing a wafer of semiconductor material; forming, inside the wafer, a plurality of passages forming a labyrinthine cavity and laterally delimiting a plurality of pillars of semiconductor material; and oxidizing the pillars of semiconductor material to form a buried insulating layer. For forming the labyrinthine cavity, a trench is first formed in a substrate; an epitaxial layer is grown, which closes the trench at the top; the wafer is annealed so as to deform the pillars and cause them to assume a minimum-energy handlebar-like shape, and a peripheral portion of the wafer is removed to reach the labyrinthine cavity, and side inlet openings are formed in the labyrinthine cavity. Oxidation is performed by feeding an oxidizing fluid through the side inlet openings.
Abstract:
An integrated device based upon semiconductor technology, in particular a chemical microreactor, including a semiconductor body having a high-temperature operating portion and a low-temperature operating portion. The semiconductor body is provided with a thermal-insulation device including a dissipator element arranged between the high-temperature operating portion and the low-temperature operating portion. The dissipator includes a membrane connecting the high-temperature operating portion and the low-temperature operating portion, and a plurality of diaphragms that extend substantially orthogonal to the membrane and are parallel to one another.
Abstract:
Integrated microreactor, formed in a monolithic body and including a semiconductor material region and an insulating layer; a buried channel extending in the semiconductor material region; a first and a second access trench extending in the semiconductor material region and in the insulating layer, and in communication with the buried channel; a first and a second reservoir formed on top of the insulating layer and in communication with the first and the second access trench; a suspended diaphragm formed by the insulating layer, laterally to the buried channel; and a detection electrode, supported by the suspended diaphragm, above the insulating layer, and inside the second reservoir.
Abstract:
The process comprises the steps of forming, on top of a semiconductor material wafer, a holed mask having a lattice structure and comprising a plurality of openings each having a substantially square shape and a side with an inclination of 45null with respect to the flat of the wafer; carrying out an anisotropic etch in TMAH of the wafer, using said holed mask, thus forming a cavity, the cross section of which has the shape of an upside-down isosceles trapezium; and carrying out a chemical vapor deposition using TEOS, thus forming a TEOS layer which completely closes the openings of the holed mask and defines a diaphragm overlying the cavity and on which a suspended integrated structure can subsequently be manufactured.