Abstract:
The present invention describes a process for realizing buried microchannels (10) in an integrated structure (1) comprising a monocrystalline silicon substrate (2). Advantageously, according to the invention, the process provides to form in the substrate (2) at least one trench (4) and to obtain microchannels (10) starting from a deep cavity characterised by a small surface port obtained through anisotropic etching of the at least one trench (4). Microchannels (10) are completely buried in the substrate (2) in a completely microcrystalline structure.
Abstract:
A miniscule fuel cell is realized on a doped monocrystalline silicon subtrate. The microporous catalytic electrodes permeable to a gaseous fuel or an oxygen containing gas are constituted by a plurality of coplanar and parallel strips (3,4) of a catalytic metallic material electroplated or sputtered over an heterogeneous columnar skeleton structure of monocrystalline silicon (1,2) purposely formed by etching the silicon substrate to realize the plurality of parallel trenches (7,8) for ducting reagent and products of the electrode reactions to and from the microporous catalytic electrode formed thereon. The spaced parallel strips (3,4) constituting the microporous catalytic electrode permeable to gases are electrically connected one to the other by parallel strips (5,6) of conducting material alternate to the microporous strips of catalytic electrode material. The whole composite electrode structure of the half-cell is in electrical contact with the conducting substrate of monocrystalline silicon in correspondence of said strips of conducting material deposited over the crests of separation between adjacent parallel trenches etched in the silicon substrate, and optionally also in correspondence of the heterogeneous columnar skeleton of conducting monocrystalline silicon in case it is not completely removed by an eventual chemical and/or electrochemical final etching step after having deposited thereon the catalytic metal to form a self-sustaining microporous structure. Two half-cells thus formed on distinct silicon substrates are thereafter placed one against the other sandwiching, at least over the cell area, a thin film of permionic membrane substantially impermeable to fluids.
Abstract:
The present invention refers to a process for the obtainment of a semiconductor comprising a suspended micro-system, to a device so obtained and its applications. In one embodiment the process for the obtainment of a semiconductor device comprising a suspended micro-system comprises the phases of: forming a silicon substrate (10); forming a silicon porous layer (11) above said substrate (10); oxidizing said porous layer (12); depositing on the whole device an oxide layer (13); depositing above said oxide layer (13) a first polysilicon layer (14); removing selectively said first polysilicon layer (14), said oxide layer (13) and said porous layer (12); depositing on the whole device a nitride layer (16); depositing on the whole device a second polysilicon layer (17); removing selectively said second polysilicon layer (17), said nitride layer (16), said first polysilicon layer (14), and said oxide layer (13); removing said porous layer (12) in the areas made accessible by the preceding phase.