HETEROSTRUCTURES

THE GOAL OF PHASE I IS TO DEMONSTRATE AN ADVANCED TECHNIQUE FOR THE GROWTH OF MULTILAYERS OF MERCURY CADMIUM TELLURIDE (MCT) AT LOW TEMPERATURE (<350 DEG C) FOR IR DETECTOR APPLICATIONS. THE OBJECTIVES ARE TO OBTAIN: 1) GROWTH OF UNIFORM LARGE AREA DEVICE QUALITY LAYERS AT LOW TEMPERATURE. 2) MULTILAYER STRUCTURES INCLUDING N/P JUNCTIONS. THE LAYERS ARE GROWN BY A NEW VAPOR-PHASE METHOD WHICH YIELDS COMPOSITIONS COVERING THE ENTIRE ALLOY RANGE BETWEEN HGTE AND CDTE. INDEPENDENT CONTROL OF THE FOUR PRINCIPAL PARAMETERS THAT DETERMINE THE COMPOSITION; THE SUBSTRATE TEMPERATURE AND THE PARTIAL PRESSURES OF HG, CD AND TE IS ACHIEVED IN AN OPEN-TUBE SYSTEM THAT UTILIZES SEPARATE ELEMENTAL SOURCES. THE GROWTH OF DEVICE QUALITY EPILAYERS INCLUDING LAYERS SUITABLE FOR RESONANT OPTICAL CAVITY (ROC) APPLICATIONS, HAS ALREADY BEEN DEMONSTRATED. ANTICIPATED BENEFITS ARE: 1) THE PROCESS CAN MEET THE REQUIREMENTS OF COST EFFECTIVE PRODUCTION AND SAFETY AND 2) THE REACTOR IS OF SIMPLE CONSTRUCTION AND UTILIZES THE ELEMENTS DIRECTLY. THE REACTOR IS PRESENTLY IN OPERATION AND INITIAL RESULTS INDICATE THAT THE OBJECTIVES CAN BE REALIZED.