Low Temperature Growth of HgTe by a UV Photosensitisation Method

Abstract

The binary semi-metal HgTe is an end member of the important infrared detector alloy Cd_xHg_1-xTe. As the requirement for low temperature epitaxial growth of this alloy is due to the instability of Hg in the lattice, the compound, HgTe, is an important material to investigate with new, low temperature growth techniques. Previous publications have considered the limitation on low temperature growth of Cd_xHg_1-xTe by Metal-Organic Vapour Phase Epitaxy (MOVPE) to be related to the thermal stability of the Te metal-organic; the preferred source being diethyltelluride (Et₂Te) [1–5]. Significant growth rates are not achieved by pyrolysis below 400°C but control during growth of the electrically active Hg vacancy requires growth temperatures below 300°C. A further attraction of low temperature growth is the potential ability to grow abrupt HgTe/CdTe interfaces and hence superlattice structures [6].