Annealing study of a bistable cluster defect

This work deals with the influence of neutron and proton induced cluster related defects on the properties of n-type silicon detectors. Defect concentrations were obtained by means of Deep Level Transient Spectroscopy (DLTS) and Thermally Stimulated Current (TSC) technique, while the full depletion voltage and the reverse current were extracted from capacitance–voltage (C–V) and current–voltage (I–V) characteristics.The annealing behaviour of the reverse current can be correlated with the annealing of the cluster related defect levels labeled E4aE4a and E4bE4b by making use of their bistability. This bistability was characterised by isochronal and isothermal annealing studies and it was found that the development with increasing annealing temperature is similar to that of divacancies. This supports the assumption that E4aE4a and E4bE4b are vacancy related defects. In addition we observe an influence of the disordered regions on the shape and height of the DLTS or TSC signals corresponding to point defects like the vacancy-oxygen complex.