US 6,388,256 B1 · Thermal detector array

Abstract

A thermal detector device comprising an array of thermal detector elements, an array of microbridge structures comprising the array of thermal detector elements, readout silicon integrated circuitry (ROIC) and an interconnect layer on which the array of microbridge structures are arranged. The interconnect layer comprises a plurality of conducting interconnect channels providing an electrical connection between the microbridge structures and input contacts on the ROIC such that the microbridge structures are in electrical contact with, but are separated from, the readout silicon integrated circuitry. As the interconnect layer separates the microbridge structures from the ROIC, the detector material, typically a ferroelectric material, may be fabricated on the microbridge structures at a deposition or anneal temperature which is not limited by the avoidance of damage to the ROIC. Deposition temperatures of at least 500° C. or, preferably, at higher temperatures e.g. 700° C.-900° C., may therefore be used, enabling the fabrication of high performance ferroelectric or microbolometer thermal detector arrays. The invention also relates to a method of fabricating high performance thermal detector arrays comprising an interconnect layer.

Claims22

Dependent claims

A method of fabricating a thermal detector device characterised by the steps of;

(i) providing an interconnect layer having front and rear surfaces, wherein the interconnect layer is a wafer comprising a plurality of interconnect channels between said front and rear surfaces,
(ii) fabricating an array of thermal detector elements as an array of microbridge structures on the interconnect layer, wherein each microbridge structure includes a common contact and an output contact, each of the common contacts being in electrical contact with the each of the other common contacts and each interconnect channel being in contact with the output contact on one of the microbridge structures, and
(iii) subsequently bonding the interconnect channels at the rear surface of the interconnect layer to readout silicon integrated circuitry, such that the microbridge structures are in electrical contact with, but are physically separated from, the readout integrated circuitry.

Dependencies are inferred from the claim text.

Thermal detector array

Life of this patent

Thermal detector array

Life of this patent

Abstract

Claims22