Variability in damage equivalence metrics between heavy ions and neutrons

There is an ongoing effort to use heavy ion damage to simulate displacement damage from neutrons. The concept of "equivalent'" damage between two types of irradiation is a topic of much interest. This paper examines the variation/consistency between several measured damage metrics from neutrons and ions from particle accelerators. Metrics considered include measured early- and late-time gain degradation in transistors, the type and number of defects as measured in deep level transient spectroscopy (DLTS), and calculated metrics such as the ratio of freely migrating defects to cluster defect or the size of a defect cluster. Careful selection of ion energies and fluences can achieve good agreement with the time dependent degradation occurring from neutron irradiations.