Effects of ion implantation on deep electron traps in Hg0.7Cd0.3Te

Abstract

Ion implantation is commonly used to create n+ on p junctions for photovoltaic detectors in HgCdTe. This process is known to create a high level of donors due to lattice damage. This work reports results of a deep level transient spectroscopy (DLTS) study of traps in n-type Hg0.7Cd0.3Te also associated with the implant induced lattice damage. A new trapping center is found at Ec−0.19 eV which is distinctly due to implant damage. The electron trapping characteristics of this level are unusual, showing a small capture cross section of σn=5×10−21 cm2 and a large barrier potential to electron capture. This indicates a weak electron trap and implies a strong hole trapping nature. As yet, these data do not account for shortened lifetimes seen in n+ on p diodes formed by ion implantation.