Engineering topics

Barrett, J. R.

Publications and source records attributed to Barrett, J. R..

3 records

NASA NTRS1983

Lead sulfide - Silicon MOSFET infrared focal plane development

A process for directly integrating photoconductive lead sulfide (PbS) infrared detector material with silicon MOS integrated circuits has been developed primarily for application in long (greater than 10,000 detector elements) linear arrays for pushbroom scanning applications. The processing technology is based on the conventional PMOS and CMOS technologies with a variation in the metallization. Results and measurements on a fully integrated eight-element multiplexer are shown.

Barrett, J. R.↗

NASA NTRS1983

Monolithic lead salt-silicon focal plane development

This paper is a summary of work done in the development of monolithic lead salt-silicon infrared focal plane technology. The photoconductive detector materials, PbS and PbSe are chemically deposited onto premetallized silicon MOSFET integrated circuit wafers. A variety of structures based on an implanted PMOS process were fabricated and evaluated. Operational results of an eight-element PbS array multiplexed on-chip are presented along with radiometric measurements on other integrated PbS-silicon MOSFET structures. PbS imagery is shown using one element of a 20-element array integrated on-chip.

Barrett, J. R.↗

NASA NTRS1982

A monolithic lead sulfide-silicon MOS integrated-circuit structure

A technique is developed for directly integrating infrared photoconductive PbS detector material with MOS transistors. A layer of chromium, instead of aluminum, is deposited followed by a gold deposition in order to ensure device survival during the chemical deposition of the PbS. Among other devices, a structure was fabricated and evaluated in which the PbS was directly coupled to the gate of a PMOS. The external bias, load, and source resistors were connected and the circuit was operated as a source-follower amplifier. Radiometric evaluations were performed on a variety of different MOSFETs of different geometry. In addition, various detector elements were simultaneously fabricated to demonstrate small element capability, and it was shown that elements of 25 x 25 microns could easily be fabricated. Results of room temperature evaluations using a filtered 700 K black body source yielded a detectivity at peak wavelength of 10 to the 11th cm (root Hz)/W at 100 Hz chopping frequency.

Jhabvala, M. D.↗