Structure with a moving portion and a buried electrode for movement detection included in a multi-substrate configuration
A device being a micro-system and/or a nano-system which includes a first substrate, having at least one lower electrode and at least one dielectric layer, and includes an intermediate substrate extending across a main plane of the device and including a moving portion. The intermediate substrate is attached, outside the moving portion, by molecular bonding to the first substrate. The moving portion faces at least a portion of the lower electrode. The device also includes an upper substrate, attached to the intermediate substrate. The moving portion is movable between the lower electrode and the upper substrate. The first, intermediate, and upper substrates extend in a plane parallel to the main plane of the device. The lower electrode detects a component of the movement of the moving portion perpendicular to the plane of the device.
1. A device being a micro-system and/or a nano-system, said device comprising:
a first substrate, including at least one lower electrode, and at least one dielectric layer;
an intermediate substrate, extending across a main plane of the device, including a moving portion, and attached, outside the moving portion, by molecular bonding to the first substrate, where the moving portion is facing at least a portion of the lower electrode;
an upper substrate, attached to the intermediate substrate;
said moving portion being movable between the lower electrode and the upper substrate;
each of said first substrate, said intermediate substrate, and said upper substrate extending in a plane parallel to the main plane of the device; and
said lower electrode detecting a component of the movement of said moving portion, said component of the movement being perpendicular to said plane of the device.
2. A device according to claim 1 , where the upper substrate includes at least one upper electrode, where the moving portion faces at least a portion of the upper electrode, and where said moving portion is movable between the lower electrode and the upper electrode.
3. A device according to claim 2 , further comprising an electrical contact between the lower electrode and the upper electrode.
4. A device according to claim 1 , further comprising an electrical contact between the lower electrode and the first substrate.
5. A device according to claim 1 , where the upper substrate is fixed securely to the intermediate substrate by a sealing bead.
6. A device according to claim 1 , where the intermediate substrate is made from monocrystalline silicon.
7. A device according to claim 1 , where the upper substrate is attached to the intermediate substrate hermetically.
8. A device according to claim 1 , where the upper substrate is a CMOS device.
9. A device according to claim 1 , where the lower substrate includes at least one alignment mark.
10. A device according to claim 1 , where the lower substrate includes at least one portion made from a monocrystalline or polycrystalline semiconducting material, or forming an SOI substrate, or composed of several stacked materials.
11. A device according to claim 1 , where the lower electrode includes lower electrode zones insulated from one another by at least a portion of dielectric material and/or at least one etched zone.
12. A device according to claim 1 , where the movement of the moving portion has a further component in a plane parallel to the main plane.
13. A device according to claim 1 , wherein the lower electrode is in a semiconductor material.