Cluster related hole traps with enhanced-field-emission—the source for long term annealing in hadron irradiated Si diodes

Cluster related defects were investigated by the thermally stimulated current (TSC) method in neutron irradiated $n$-type Si diodes during $80°C$ annealing. Three hole traps labeled $H$ $(116K)$⁠, $H$ $(140K)$⁠, and $H$ $(152K)$ proved to have an electric-field-enhanced emission characteristic of Coulombic wells. Their zero field emission rates were deduced describing the TSC peaks with the three-dimensional Poole-Frenkel formalism when accounting for the electric field distribution. As acceptors in the lower half of the gap, these centers have a direct impact on the effective doping of the $n$-type diodes. They are revealed as causing the long term annealing effects.