Bandgap-Engineering of HgCdTe for Two-Color Ir Detector Arrays BY Movpe

Abstract

Recent results on MOVPE growth of multilayer two-color HgCdTe detectors, for simultaneous and independent detection of medium wavelength (MW, 3–5 μm) and long wavelength (LW, 8–12 μm) bands, are reported. The structures are grown in situ on lattice matched (100) CdZnTe in the double-heterojunction p-n-N-P configuration. A barrier layer is placed between the LW and MW absorber layers to prevent diffusion of MW photocarriers into the LW junction and thereby eliminate spectral crosstalk. X-ray double crystal rocking curve widths are ∼ 45 arc-secs, indicating good epitaxial quality. SIMS depth profile measurements of these 28 μm thick structures show well-defined alloy compositions, and arsenic and iodine doping. SIMS data on a series of thirteen films show that good run-to-run repeatability is obtained on thicknesses, compositions, and dopant levels with values close to the device design targets. Depth profile of etch pits through the thickness of the films show etch pit densities in the range of 8×105-5×106 cm−2.

MOVPE growth of HgCdTe for high performance 3–5 µm photodiodes operating at 100–180K

“…1,2,4 During the course of this work, the reactor system was modified to incorporate segmented infrared lamp heating in place of the previous radio frequency (rf) induction heating, along with substrate rotation. This modification significantly improved the temperature uniformity over the growth susceptor, and consequently improved the composition and thickness uniformity of the HgCdTe films.…”

“…1 These advances have led to high performance HgCdTe two-dimensional detector arrays for single-band as well as simultaneous MW/ LW dual-band operation. [2][3][4] In this paper, we report MOVPE in situ growth of MWIR HgCdTe photodiodes for operation at 100-180K. The device consists of a three-layer MWIR P-n-N photodiode detector.…”

HgCdZnTe quaternary materials for lattice-matched two-color detectors

“…[1][2][3] Since that time two-color FPAs have primarily been developed using the more flexible vapor phase growth techniques of molecular beam epitaxy (MBE) for MWIR/MWIR, 4-9 MWIR/LWIR, 10,11 and LWIR/LWIR 12 FPAs and metalorganic vapor phase epitaxy (MOVPE) for MWIR/LWIR FPAs. [13][14][15][16] These vapor phase growth techniques enable the more complex device structures that are needed for realizing high-performance multicolor FPAs. A review of this two-color technology is given in these proceedings.…”