MODELING OF 3-D DIFFRACTION AND SCATTERING FROM SUBMICRON OBJECTS ON SILICON FOR PARTICULATE MONITORING AND PHOTOLITHOGRAPHY

IN PHASE I, WE PROPOSES TO USE THREE-DIMENSIONAL NUMERICAL SOLUTIONS OF MAXWELL'S EQUATIONS TO SHOW THAT DIFFRACTION AND SCATTERING PROBLEMS IN PHOTOLITHOGRAPHY AND DEFECT INSPECTION CAN BE ADDRESSED BY ANALYSIS. THESE SOLUTIONS WILL DEVELOP DATA OF GREAT BENEFIT TO MANUFACTURERS OF INTEGRATED CIRCUITS. THE MODELING OF 3-D DIFFRACTION AND SCATTERING PATTERNS BEARS ON THE FOLLOWING TOPICS: 1. THE PRINTABILITY OF DEFECTS AS CAUSED BY PARTICLES FALLING ON THE WAFER DURING INTEGRATED CIRCUIT PROCESSING AND FABRICATION. 2. PARTICULATE MONITORING DURING ALL STAGES OF INTEGRATED CIRCUIT WAFER FABRICATION. ALTHOUGH NUMERICAL SOLUTIONS TO MAXWELL'S EQUATIONS HAVE BEEN AVAILABLE FOR SOME TIME, TO APPLY SUCH METHODS IN 3-D REQUIRES SUPERCOMPUTERS. THE PHASE I CALCULATIONS WILL BE PERFORMED USING WEIDLINGER ASSOCIATES' VECTORIZED SOFTWARE ON A CRAXY X-MP SUPERCOMPUTER. NUMERICAL RESULTS WILL BE COMPARED WITH EXPERIMENTAL DATA PERTAINING TO PARTICULATE MONITORING. THESE EXPERIMENTS, TO BE CONDUCTED BY TENCOR INSTRUMENTS, WILL MEASURE THE ANGULAR SCATTERING PATTERN FROM SPHERES ON A SUBSTRATE. THIS WORK APPLIES TO EVALUATING PRINTABILITY OF DEFECTS IN INTEGRATED CIRCUITS AND TO PARTICULATE MONITORING DURING ALL STAGES OF IC WAFER FABRICATION. THESE PROBLEMS ARE INHERENTLY THREE-DIMENSIONAL. A STUDY OF THESE EFFECTS WOULD BE OF GREAT BENEFIT TO THE IC INDUSTRY.