Molecular beam epitaxy growth of antimony-based mid-infrared interband cascade photodetectors

Abstract

The molecular beam epitaxial growth and optimization of antimony-based interband cascade photodetectors, on both GaSb and GaAs substrates, are presented. Material characterization techniques, including X-ray diffraction, atomic force microscopy, and crosssectional transmission electron microscopy, are used to evaluate the epitaxial material quality. This work has led to the demonstration of mid-infrared photodetectors operational up to a record-high 450 K, and a dark current density as low as 1.10×10 -7 A/cm 2 at 150 K. The results also suggest that further improved material quality and device performance can be expected via optimization of growth parameters.

Progress on the development of interband cascade photodetectors

“…Further details about the epitaxial growth can be found in Ref. 8. Three 5-stage MWIR IC detector samples are grown, and these samples are identical other than the absorber thicknesses.…”

“…The root mean square (RMS) roughness obtained from a 5×5 µm 2 AFM topography is around 3.5 Å [8]. The samples were then processed into deep-etched mesa-type photodiodes using standard contact UV lithography and wet-chemical etching.…”

Monolithic fabrication of InSb-based photo-pixel for Mid-IR imaging

“…4. The integration method used in this work can be easily migrated to other III-V materials with SI GaAs substrate growth capabilities such as InAsSb and type-II InAs/GaSb superlattices [6] [7], therefore alternative semiconductor layer structures could also be investigated. This heterogeneous technology creates great potential to realize a new type of monolithic focal plane array for imaging in the MWIR range without the need for flip-chip bonding to a ROIC.…”