HgCdTe photodiode mosaics on vapor phase epitaxial layers

The ever-increasing pace in the development of high performance infrared components for imaging application (MIS, photodiodes, photoconductors) and in the field of monolithic electronics (CCD, CID) has clearly demonstrated the importance of HgcdTe. the ability to fabricate devices with a large number of elements (about 10⁴in the case of focal plane) hinges essentially on the ability to fabricate metallurgically a base meterial of excellent electronic properties and very high uniformity. These requirements could hitherto not be satisfied by traditional growth methods, in particular because of phenomena affecting changes in composition and phase segregation related to a relatively broad phase diagram. This difficulty is resolved by the vapor phase epitaxial deposition process. The isothermal growth process (1) (EDRI method)** was selected because it was simple to implement and because the prepared layers yielded, in addition to their mirror-like surface, execellent crystalline and electronic properties (2) and remarkable uniformity of composition (3).