High MTF optical coating for hybrid UFPA's

Details High MTF optical coating for hybrid UFPA's High MTF optical coating for hybrid UFPA's

1997-01-24

2001-06-12

Graybill, David E. (Department: 2814)

Semiconductor device manufacturing: process

Making device or circuit responsive to nonelectrical signal

Thermally responsive

C438S065000, C438S069000, C438S072000, C438S073000

Reexamination Certificate

active

06245591

ABSTRACT:

FIELD OF THE INVENTION
This invention generally relates to infrared or thermal imaging systems, and more specifically to the optical coating of a thermal (infrared) detector array, or hybrid uncooled focal plane array (UFPA).
BACKGROUND OF THE INVENTION
Infrared or thermal imaging systems typically use thermal sensors to detect infrared radiation and produce an image capable of being visualized by the human eye. Some examples of such thermal imaging devices include night vision equipment and law enforcement surveillance equipment.
Several prior art references disclose infrared imaging arrays and methods for producing such arrays. U.S. Pat. No. 4,080,532 issued to Hopper; and U.S. Pat. Nos. 4,745,278 and 4,792,681 issued to Hanson utilize ferroelectric materials for infrared detection. Thermal imaging by means of uncooled sensors is described in a paper entitled
Low-cost Uncooled Focal Plane Array Technology
written by Hanson, Beratan, Owen and Sweetser presented Aug. 17, 1993 at the IRIS Detector Specialty Review.
SUMMARY OF THE INVENTION
The present invention is a method for fabricating a hybrid thermal detector structure, comprising the steps of reticulating at least three pixels in a thermally sensitive dielectric, depositing an electrically conductive layer on a first side of the pixels, depositing a precursor film on the electrically conductive layer, gelling the precursor film to form a porous film, attaching electrical contacts to a second side of the pixels, and coupling the electrical contacts to a sensing integrated circuit structure. Radiation may be absorbable by the porous film.
The present invention also entails a hybrid thermal detector structure, comprising an infrared sensing array comprising at least three thermally sensitive pixels, backside contacts abutting one side of the pixels, and an optical coating in contact with an opposite side of the pixels, the optical coating comprised of a porous film; and a sensing integrated circuit structure comprised of interconnect metal coupled at one end to an thermal isolation structure, and integrated circuitry coupled to the other end of the interconnect metal; where the electrical contacts of the infrared sensing array coupled to the interconnect metal of the sensing integrated circuit structure.
Advantages of the invention include improved MTF (Modulation Transfer Function) and improved image acuity of the hybrid thermal detector. A layer of the optical coating may be eliminated with the present invention. The need to reticulate the optical coating may be eliminated. The invention also allows thinner, more responsive devices due to reduced parasitic thermal mass of the porous optical coating.


REFERENCES:
patent: 4994672 (1991-02-01), Cross et al.
patent: 5093735 (1992-03-01), Doane et al.
patent: 5424544 (1995-06-01), Shelton et al.
patent: 5457318 (1995-10-01), Robinson et al.
patent: 5461003 (1995-10-01), Havemann et al.
patent: 5470802 (1995-11-01), Gnade et al.
patent: 5476817 (1995-12-01), Numata
Hrubesh, Lawrence W. et al., Processing and Characterization of High Porosity Aerogel Films, Advances in Porous Materials Materials Research Society Symposium Proceedings v 371. Materials Research Society, p. 195-204. (best date available), 1995.*
Hrubesh, Lawrence W. et al., Processing and Characterization of High Porosity Aerogel Films, (only abstract availabel) UCRL-JC-117554; CONF-941144-176, Nov. 1994.

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