OF SILICON DEVICES TO ALPHA PARTICLE RADIATION

SOFT ERRORS INDUCED BY IONIZING PARTICLES CONSTITUTE ONE OF THE MOST PRESSING PROBLEMS OF PRESENT SEMICONDUCTOR TECHNOLOGY. HARDENING MEASURES HAVE BEEN ATTEMPTED EMPIRICALLY AND THROUGH CIRCUIT SIMULATION, DESIGN MODIFICATION, AND DEVICE SIMULATION. A NECESSARY COMPONENT TO THESE STUDIES IS AN ACCURATE REPRESENTATION OF CIRCUIT RESPONSE, CHARGE COLLECTED, AND IN SOME CASES THE FUNNEL LENGTH. INSOFAR AS SIGNIFICANT TIME TRANSIENTS FOLLOWING AN ALPHA STRIKE OCCUR USUALLY WITHIN THE FIRST TWO NANOSECONDS, PREDICTABLE CAPABILITY FOR DIFFERENT DEVICE STRUCTURES WITHIN THIS TIME FRAME IS NEEDED. THIS CAN ONLY BE OBTAINED THROUGH NUMERICAL SIMULATION. NUMERICAL SIMULATION OF THE TRANSIENT RESPONSE HAS TENDED TO RELY HEAVILY ON TWO DIMENSIONAL ALGORITHMS. THESE TWO DIMENSIONAL ALGORITHMS, WHILE EXTREMELY VALUABLE FOR ASCERTAINING IMPORTANT PHENOMENOLOGY, WILL NOT ACCURATELY REPRESENT THE THREE DIMENSIONAL NATURE OF THE PROBLEM PARTICULARLY WHEN DEVICE GEOMETRIES ARE REDUCED IN SIZE. THE PRESENT PROPOSAL DEALS WITH EXTENDING RESEARCH ASSOCIATES' CAPABILITY FOR TREATING THREE DIMENSIONAL SEMICONDUCTOR TRANSPORT PROBLEMS TO THE IMPORTANT AREA OF THREE DIMENSIONAL TRANSIENTS ASSOCIATED WITH INCIDENT RADIATION EFFECTS. THE PROBLEM TO BE STUDIED IS THAT OF A NP JUNCTION DEVICE WITH EDGES NOT GREATER THAN FIVE MICRONS, AND ITS TRANSIENT RESPONSE TO AN ALPHA PARTICLE INCIDENT THROUGH THE N WELL.