US 12,704,666 B2Granted

Micro-electromechanical optical shutter with translating shielding structures and related manufacturing process

AssigneeSTMicroelectronics S.r.l.

InventorsFederico Vercesi, Nicolo′ Boni, Fabrizio Cerini, Luca Guerinoni

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Abstract

A MEMS shutter including: a semiconductor substrate traversed by an aperture; a first semiconductor layer and a second semiconductor layer, which form a supporting structure fixed to the substrate; a plurality of deformable structures, each of which is formed by a corresponding portion of at least one between the first and second semiconductor layers; a plurality of actuators; a plurality of shielding structures, each of which is formed by a corresponding portion of at least one between the first and second semiconductor layers, the shielding structures being arranged angularly around the underlying aperture so as to provide shielding of the aperture, each shielding structure being further coupled to the supporting structure via a deformable structure. Each actuator may be controlled so as to translate a corresponding shielding structure between a first position and a second position, thus varying shielding of the aperture; the first and second positions of the shielding structures are such that, in at least one operating condition, pairs of adjacent shielding structures at least partially overlap one another.

Claims22

Dependent claims

A MEMS shutter, comprising:

a substrate;
a main aperture through the substrate;
a first semiconductor layer on the substrate;
a second semiconductor layer on the first semiconductor layer;
a plurality of deformable structures, each being a portion of at least one of the first and second semiconductor layers;
a plurality of actuators;
and
a plurality of shielding structures, each including a portion of at least one of the first and second semiconductor layers, the shielding structures being around the main aperture, each shielding structure being coupled to a corresponding deformable structure, pairs of adjacent shielding structures are configured to at least partially overlap one another in at least one operating condition,
each of the plurality of deformable structures including:
a cantilever structure;
and
a deformable coupling structure, which has its ends fixed to the cantilever structure and to a corresponding shielding structure and is compliant in a direction parallel to an axis perpendicular to the substrate and in a direction parallel to a respective structure direction, which is perpendicular to the axis,
the deformable coupling structure including at least one elongated elastic structure, which, in a resting condition, extends in a transverse direction, which is perpendicular to the axis and to the respective structure direction, and has, in a plane parallel to the axis and to the respective structure direction, a first principal axis of inertia and a second principal axis of inertia, each of which is transverse with respect to the axis and to the respective structure direction, so that movements along the axis of the end the deformable coupling structure fixed to the corresponding cantilever structure cause corresponding movements along the respective structure direction of the end of the deformable coupling structure fixed to the corresponding shielding structure;
and
a constraint structure coupled to the shielding structure and is rigid along the axis and is compliant in a plane perpendicular to the axis.

12 more elements

A device, comprising:

a micro-electromechanical shutter that includes:
a substrate;
an aperture through the substrate;
a first semiconductor layer on the substrate;
a second semiconductor layer on the first semiconductor layer;
a plurality of cantilever structures coupled to the substrate around the aperture;
a plurality of first shielding regions coupled to first ones of the plurality of cantilever structures by a plurality of first elastic structures;
and
a plurality of second shielding regions coupled to second ones of the plurality of cantilever structures by a plurality of second elastic structures,
the plurality of second shielding regions being closer to the aperture than the plurality of first shielding regions,
each of the plurality of cantilever structures including a respective first portion of the first semiconductor layer and a respective first portion of the second semiconductor layer directly overlying the respective first portion of the first semiconductor layer;
each of the plurality of first elastic structures and the plurality of second elastic structures including a respective second portion of the first semiconductor layer and a respective second portion of the second semiconductor layer directly overlying the respective second portion of the first semiconductor layer, and
each of the plurality of first shielding regions and the plurality of second shielding regions including a respective third portion of the first semiconductor layer and a respective third portion of the second semiconductor layer directly overlying the respective third portion of the first semiconductor layer.

10 more elements

A device, comprising:

a substrate;
an aperture through the substrate;
a first semiconductor layer on the substrate;
a second semiconductor layer on the first semiconductor layer;
a plurality of cantilever structures on the substrate, each of the plurality of cantilever structures including a respective first portion of the first semiconductor layer and a respective first portion of the second semiconductor layer directly overlying the respective first portion of the first semiconductor layer;
a plurality of elastic structures coupled to the plurality of cantilever structures, respectively, each of the plurality of elastic structures including a respective second portion of the first semiconductor layer and a respective second portion of the second semiconductor layer directly overlying the respective second portion of the first semiconductor layer;
and
a plurality of shielding structures coupled to the plurality of elastic structures, respectively, each of the plurality of shielding structures including a respective third portion of the first semiconductor layer and a respective third portion of the second semiconductor layer directly overlying the respective third portion of the first semiconductor layer, the plurality of shielding structures overlapping the aperture.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/058,147Filed 22 Nov 2022
Priority: IT 10202100003027530 Nov 2021
Published: US 2023/0168415 A11 Jun 2023
Granted: 11 Aug 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

G02B 5/005
Optical elements other than lenses: diaphragms
G02B 26/02
Optical devices or arrangements for the control of light using movable or deformable optical elements: for controlling the intensity of light
H02N 1/006
Electrostatic motors: of the gap-closing type
H02N 2/028
Producing linear motion, e.g. actuators; Linear positioners ; Linear motors: along multiple or arbitrary translation directions, e.g. XYZ stages