Method for growing a HgCdTe epitaxial layer on a semiconductor substrate

A method for growing a Hg.sub.1-x Cd.sub.x Te epitaxial layer on a substrate, where x is the mole fraction of CdTe in said Hg.sub.1-x Cd.sub.x Te epitaxial layer, said method comprising:

• providing a substrate that is formed from a material which does not interdiffuse with a semiconductor layer deposited thereon;
• forming a CdTe layer on said substrate;
• providing a Te-rich Hg-Cd-Te source expressed by (Hg.sub.1-z Cd.sub.z).sub.1-y Te.sub.y, wherein y is the mole fraction of Te, z(1-y) is the mole fraction of Cd and (1-z) (1-y) is the mole fraction of Hg in said Te-rich Hg-Cd-Te source;
• placing said source and said substrate with the CdTe layer thereon in an enclosure;
• heating said source and said substrate with the CdTe layer thereon in said enclosure;
• independently controlling the temperature of the substrate and the temperature of the source so as to establish three-phase equilibrium conditions in said enclosure, the temperature of the source being controlled to provide a stoichiometric Hg.sub.1-x Cd.sub.x' Te solid phase and a Te-rich HgCdTe liquid phase in said source and the temperature of the substrate being controlled to cause isothermal growth forming a Hg.sub.1-x Cd.sub.x Te layer on said substrate by transportation of vapors from the source to said CdTe layer on the substrate, said x' being the mole fraction of CdTe in said stoichiometric solid phase;
• and
• maintaining said three-phase equilibrium conditions in said enclosure until the entirety of said CdTe layer is converted into said Hg.sub.1-x Cd.sub.x Te epitaxial layer.