ACHIEVEMENT OF HIGH QUALITY CDZNTE SUBSTRATES USING AN IMPROVED CRYSTAL GROWTH PROCESS

MONOCRYSTALLINE SUBSTRATE OF CDZNTE (4 AT% ZN), NOMINALLY LATTICE MATCHED TO HGCDTE (20 AT% CD), WILL BE PREPARED FROM CRYSTALS GROWN BY A NEW PROCESS. THE NEW CRYSTAL GROWTH SYSTEM IS FREE OF QUARTZ AND PROVIDES IMPROVED GROWTH CONDITIONS THROUGH 1) TEMPERATURE PROFILING AND PRESSURE CONTROL TECHNIQUES THAT CANNOT BE USED IN CONVENTIONAL GROWTH SYSTEMS BECAUSE OF TEMPERATURE AND PRESSURE LIMITATIONS ON QUARTZ AND 2) REMOVAL OF COMTAMINATION PROBLEMS RELATED TO QUARTZ. IT IS EXPECTED THAT SUBSTRATES OF HIGH PURITY, EXCELLENT CRYSTAL MORPHOLOGY AND AREAS GREATER THAN 25 CM WILL BE PRODUCED. CHARACTERIZATION WILL INCLUDE ELECTRON MOBILITY-LIFETIME PROFILING BY ALPHA-PARTICLE EXCITATION, IN ADDITION TO STANDARD MEASUREMENTS. RESULTS OF THE PROGRAM SHOULD DEMONSTRATE THE IMPORTANCE OF A NEW CRYSTAL GROWTH METHOD IN PREPARING HIGH QUALITY SUBSTRATES OF CDTE TYPE MATERIALS, PROVIDE SIGNIFICANT NEW INFORMATION RELATED TO LATTICE MATCHING, AND INCREASE UNDERSTANDING OF THE LATTICE STABILIZING EFFECTS OF ALLOYING.