Diffusion-Time-Resolved Ion-Beam-Induced Charge Collection from Stripe-Like TestJunctions Induced by Heavy-Ion Microbeams

摘要

To design more radiation-tolerant Integrated Circuits (ICS), it is necessary todesign and test accurate models of ionizing radiation induced charge collection dynamics with microcircuits. A new technique, Diffusion Time Resolved Ion Beam Induced Charge Collection (DTNBICC), is used to measure the average arrival time of the diffused charge, which can be related to the first moment (or the average time) of the arrival carrier density at the junction. Specially designed stripe-like test junctions are experimentally studied using a 12 MeV carbon microbeam with a spot size of about 0.1 micrometer. The relative arrival time of ion-generated charge and the collected charge are measured using a multiple parameter data acquisition system. A 2-D device simulation code, MEDIC1, is used to calculate the charge collection dynamics on the stripe-like test junctions. The simulations compare very well with experimental microbeam measurements. The results show the importance of the diffused charge collection by junctions, which is especially significant for Single Event Upsets (SEUS) and Multiple Event Upset (MEUS) in digital devices. The charge sharing results also indicate that stripe-like junctions may be used as position sensitive detectors with a resolution of about 0.1 micrometer.