Ion Polishing Of Polycrystalline Diamond Interceptor Windows

CHEMICAL VAPOR DEPOSITION (CVD) AND RELATED PROCESSES HAVE BEEN DEVELOPED FOR APPLYING SYNTHETIC DIAMOND FILMS FOR THIS APPLICATION. HOWEVER, IN SPITE OF RECENT PROGRESS, CVD DIAMOND IS STILL UNSATISFACTORY, BECAUSE THE DEPOSITS ARE POLYCRYSTALLINE IN FORM WITH GRAINS OF VARYING SIZES AND ORIENTATIONS, CAUSING OPTICAL SCATTER. POLISHING OF DIAMOND FILMS WITH DIAMOND PARTICLES CAN BE USED TO REDUCE THIS SCATTER, BUT THE POLISHING IS LONG AND EXPENSIVE, AND DOES NOT PRODUCE IDEAL RESULTS. FURTHERMORE, DURING MECHANICAL POLISHING, GRAINS IN THE FILM FREQUENTLY BECOME DISLODGED, EXTENDING THE NECESSARY POLISHING TIME. SPIRE PROPOSES AN ION BEAM PROCESS TO IMPROVE THE QUALITY OF POLISHING OF POLYCRYSTALLINE DIAMOND. THE PHASE I PROGRAM WILL USE AN ELECTRON CYCLOTRON RESONANCE (ECR) PLASMA TO GENERATE THE ION BEAM FOR POLISHING POLYCRYSTALLINE DIAMOND FILMS AND WILL COMPARE RESULTS WITH THOSE FROM ION POLISHING WITH A KAUFMAN SOURCE. PROCESS PARAMETERS, SUCH AS BEAM ENERGY, CURRENT DENSITY, ION SPECIES, BACKGROUND ATMOSPHERE, AND SUBSTRATE PREPARATION AND TEMPERATURE WILL BE VARIED TO FIND PROMISING CONDITIONS FOR PHASE II OPTIMIZATION.