SILICON DOPED GALLIUM BY ION IMPLANTATION FOR IMPURITY BAND CONDUCTION DETECTORS

THIS GOAL OF THIS RESEARCH PROGRAM WILL BE THE PRODUCTION OF HEAVILY DOPED GALLIUM IN SILICON (GREATER THAN 4 X 10 ATOMS/CM ) BY ION IMPLANTATION. THE PRODUCT WILL BE ANALYZED TO DETERMINE THE CHARACTERISTICS OF IMPURITY BAND CONDUCTION AS IT APPLIES TO THE DE VELOPMENT OF A THIN (4 MICRONS) INFRARED DETECTOR. THE UES TANDETRON ION BEAM ACCELERATOR WILL BE EMPLOYED TO IMPLANT GALLIUM INTO SILICON USING SEVERAL BEAM ENERGY VALUES RANGING FROM 400 KEV TO 6 MEV, PRODUCING A UNIFORM DISTRIBUTION OF GALLIUM OVER THE FIRST 4 MICRONS. ANNEALING OF THE SILICON SURFACE TO A DEPTH SLIGHTLY GREATER THAN THE DAMAGE REGION WILL BE PREFORMED USING PULSED LASER AND INCOHERENT LIGHT OR RESISTIVE HEATING. THE RECRYSTALLIZING SOLID WILL PLACE THE GALLIUM ATOMS IN SUBSTITUTIONAL SITES AND WILL PROMOTE SINGLE CYRSTAL RECRYSTALLIZATION OF THE DAMAGED SILICON. RBS, SPREADING RESISTANCE, DLTS, HALL AND PHOTOCONDUCTIVITY EQUIPMENT WILL MEASURE DEPTH DISTRIBUTION, ANALYZE GALLIUM UNIFORMITY,DETECT IONIZED IMPURITIES AND DEFECTS, MEASURE ELECTRICAL CHARACTERISTICS OF IMPURITY BAND CON DUCTION, AND PROVIDE INFORMATION CONCERNING PHOTOCONDUCTIVITY. THE LONGER TERM GOAL OF UNDERSTANDING FTHE PHYSICAL LAWS GOVERNING THE NATURE OF IBC WILL COME FROM DATA OBTAINED FROM FUTURE STUDIES.