US 2017/0370779 A1 · UNRELEASED THERMOPILE INFRARED SENSOR USING MATERIAL TRANSFER METHOD

Abstract

An unreleased thermopile IR sensor and method of fabrication is provided which includes a new thermally isolating material and an ultra-thin material based sensor which, in combination, provide excellent sensitivity without requiring a released membrane structure. The sensor is fabricated using a wafer transfer technique in which a substrate assembly comprising the substrate and new thermally isolating material is bonded to a carrier substrate assembly comprising a carrier substrate and the ultra-thin material, followed by removal of the carrier substrate. As such, temperature restrictions of the various materials are overcome.

Claims21

Dependent claims

An unreleased thermopile infrared sensor comprising:

a substrate having a bottom surface and a top surface;
a thermally isolating material disposed on at least a portion of the top surface of the substrate, the thermally isolating material having a bottom surface and a top surface;
and
an ultra-thin material disposed on at least a portion of the top surface of the thermally isolating material;
wherein the thermally isolating material is stable at temperatures up to 450° C., and
wherein the ultra-thin material is selected from materials having a thickness of less than or equal to 200 nm, and are deposited by methods requiring a heightened temperature of greater than 450° C.

3 more elements

A method for fabricating an unreleased thermopile infrared sensor comprising:

(a) forming a substrate assembly by providing a substrate layer having a bottom surface and a top surface, and depositing a thermally isolating material layer on at least a portion of the top surface of the substrate layer;
(b) forming a carrier assembly by providing a carrier layer having a bottom surface and a top surface, optionally depositing a sacrificial layer on at least a portion of the top surface of the carrier layer, depositing an ultra-thin material layer on at least a portion of the sacrificial layer or on at least a portion of the top surface of the carrier layer, and optionally depositing a bonding layer on the ultra-thin material;
(c) stacking the carrier assembly on top of the substrate assembly by placing the ultra-thin material layer or bonding layer of the carrier assembly into contact with the thermally isolating material layer of the substrate assembly;
(d) bonding the carrier assembly to the substrate assembly to provide a bonded stack;
(e) removing the carrier layer and optional sacrificial layer from the bonded stack to provide a sensor wafer, the sensor wafer comprising the substrate layer, the thermally isolating material layer on the top surface of the substrate layer, the optional bonding layer on the thermally isolating material layer, and the ultra-thin material layer on the optional bonding layer or on the thermally isolating material layer;
and
(f) structuring the sensor wafer to provide the unreleased thermopile infrared sensor,
wherein the thermally isolating material layer is stable at temperatures up to 450° C., and the ultra-thin material layer is fabricated of one or more materials having a thickness of less than or equal to 200 nm and is deposited by methods requiring a heightened temperature of greater than 450° C.

5 more elements

Dependencies are inferred from the claim text.

Unreleased thermopile infrared sensor using material transfer method

Life of this patent

Unreleased thermopile infrared sensor using material transfer method

Life of this patent

Abstract

Claims21