One of the great advantages of Type II InAs/GaSb superlattice over other competing technologies for
the third generation infrared imagers is the potential to have excellent uniformity across a large area as
the electronic structure of the material is controlled by the layer thicknesses, not by the composition of
the materials. This can economize the material growth, reduce the fabrication cost, and especially
allow the realization of large format imagers.
In this talk, we report the molecular beam epitaxial growth of Type II superlattices on a 3" GaSb
substrate for long wavelength infrared detection. The material exhibits excellent structural, optical and
electrical uniformity via AFM, Xray, quantum efficiency and I-V measurements. At 77K, 11μm cutoff
photodiodes exhibit more than 45% quantum efficiency, and a dark current density of 1.0x10-4A/cm2 at 50 mV, resulting in a specific detectivity of 6x1011 cm.Hz1/2/W.