History of HgCdTe infrared detectors at BAE Systems

摘要

This paper describes the history and current status of HgCdTe infrared detector technology at BAE Systems in Lexington, Massachusetts, whose corporate legacy includes Honeywell (1962-991), Loral (1991-1996), and Lockheed Martin (1996-2000).The Honeywell Radiation Center was founded in 1962 in Boston, Massachusetts. Shortly thereafter, primitive HgCdTe samples began to arrive from the Honeywell Corporate Research Center in Hopkins, Minnesota for evaluation as possible IR detectors. In 1967, procedures for the growth of HgCdTe inhomogeneous large-grain-polycrystalline ingots by a modified Bridgman method were transferred from the Research Center to the Radiation Center. In 1968 the Radiation Center moved to new facilities in Lexington, Massachusetts. HgCdTe activities have expanded and evolved in the ensuing years, remaining in the Lexington, Massachusetts facilities up to the present.This paper reviews the role that the Honeywell/Loral/Lockheed Martin/BAE Systems facility in Lexington, Massachusetts has played in the success of HgCdTe as today's preeminent, highest performance, most versatile, and most widely applicable infrared detector material for the 1 -30 μm spectral range.We examine the evolution of both photoconductive and photovoltaic HgCdTe detectors from early unpassivated ill-understood single-element devices through production of linear arrays and to today's large-format two-dimensional IR Focal Plane Arrays for the most demanding spaceborne applications. We examine the progress made in HgCdTe materials science and technology, including improved highly-homogeneous bulk crystal growth, liquid phase epitaxy and metalorganic vapor phase epitaxy. Various devices are used to illustrate the evolution of HgCdTe technology, including the n-type photoconductor, the trapping-mode photoconductor, and the two-layer LPE P-on-n heterojunction.