US 12,641,387 B2Granted

Foundry-compatible process for integrated micro-speaker and microphone

AssigneeVibrant Microsystems Inc.

InventorsJoseph Doll, Sanjay Bhandari

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Abstract

A MEMS audio device includes a first substrate having a first surface, a cavity, and a first vent hole formed through the first substrate, a device layer disposed upon the first substrate comprising a semiconductor material sandwiched between a first and second oxides, wherein a portion of the semiconductor material is substantially free of oxide, wherein the first oxide is disposed against the first surface, and wherein the device layer comprises first contacts, a substrate disposed upon the device layer, including a first vent hole formed through the second substrate, and second electrical contacts coupled to the first electrical contacts, wherein the portion of the semiconductor material forms a diaphragm for the MEMS audio device and wherein the diaphragm is configured to move within the first cavity.

Claims25

Dependent claims

A Micro-Electric Mechanical System (MEMS) audio device comprising:

receiving a first wafer comprising a first substrate characterized by a first surface, wherein a first cavity is formed within the first substrate;
disposing a device layer upon the first wafer, wherein the device layer comprises a semiconductor material having a first side and a second side, wherein the semiconductor material comprises a first semiconductor material portion, wherein a first material layer is formed upon the first side, wherein a second material layer is formed upon the second side, wherein a first portion of the first material layer is disposed above the first semiconductor material portion, wherein a first portion of the second material layer is disposed below the first semiconductor material portion, and wherein the first material layer is disposed against the first surface;
forming a first plurality of contacts through the second material layer to at least the semiconductor material;
receiving a second substrate wafer, wherein a plurality of metal layers are disposed within the second substrate wafer, wherein a first plurality of vent holes are formed through the second substrate wafer, and wherein a second plurality of contacts are formed on a first surface of the second substrate;
coupling the first plurality of contacts to the second plurality of contacts;
forming a second plurality of vent holes through the first substrate, wherein a first vent hole from the second plurality of vent holes is coupled to the first cavity;
etching at least the first portion of the first material layer and the first portion of the second material layer from around the first semiconductor material portion such that the first semiconductor material portion is substantially free from the first material layer and the second material layer;
and
wherein the first semiconductor material portion forms a diaphragm for the MEMS audio device configured to move within the first cavity.

6 more elements

A Micro-Electric Mechanical System (MEMS) audio device comprising:

a first wafer comprising a first substrate characterized by a first surface and comprising a first cavity within the first substrate, wherein the first substrate comprises at least a first vent hole formed through the first substrate and coupled to the first cavity;
a device layer disposed upon the first wafer, wherein the device layer comprises a semiconductor material having a first side and a second side, wherein a first material layer is formed upon a portion of the first side, wherein a second material layer is formed upon a portion the second side, wherein a portion of the first material layer and a portion of the second material layer are removed from the semiconductor material to provide a first portion of the semiconductor material substantially free of the first material layer and the second material layer, wherein the first material layer is disposed against the first surface of the first wafer, and wherein the device layer comprises a first plurality of electrical contacts;
a second substrate wafer disposed upon the device layer, wherein the second substrate wafer comprises at least a first vent hole formed through the second substrate wafer and coupled to the first cavity, and wherein the second substrate wafer comprises a second plurality of electrical contacts coupled to the first plurality of electrical contacts;
and
wherein the first portion of the semiconductor material forms a diaphragm for the MEMS audio device and wherein the first portion of the semiconductor material is configured to move within the first cavity.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/354,432Filed 18 Jul 2023
Published: US 2025/0030998 A123 Jan 2025
Granted: 26 May 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification24 codes

H04R 19/005
Electrostatic transducers: using semiconductor materials
H04R 31/006
Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor: interconnection of transducer parts
B81B 7/0006
Microstructural systems ; Auxiliary parts of microstructural devices or systems: interconnects
B81B 7/02
Microstructural systems ; Auxiliary parts of microstructural devices or systems: containing distinct electrical or optical devices of particular…