Substrate removal for high quantum efficiency back side illuminated type-II InAs∕GaSb photodetectors

Pierre-Yves Delaunay, Bình Minh Nguyên, Darin Hofman, Manijeh Razeghi

Applied Physics Letters · 2007 · 31 citations · 9 references

Concepts

Abstract

A substrate removal technique using an InAsSb etch stop layer improves by a factor of 2 the quantum efficiency of back side illuminated type-II InAs∕GaSb superlattice photodetectors. After etching of the GaSb substrate with a CrO3 based solution, the quantum efficiency of the diodes presents Fabry-Pérot oscillations averaging at 56%. Due to the confinement of the infrared light inside the devices, the quantum efficiency for certain devices reaches 75% at 8.5μm. The implementation of this new technique to a focal plane array resulted in a decrease of the integration time from 0.23to0.08ms.

References

9