Neutron Produced Trapping Centers in Junction Field Effect Transistors

The junction field effect transistor has been employed to study trapping centers introduced in silicon by fast neutron irradiation. Extensive measurements have been made of both the static and dynamic characteristics of irradiated devices. The effects of neutron-produced traps have been explored in both n and p channel devices, as a function of neutron fluence and dopant concentration. The trapping center effects on small signal transconductance and large signal pulse response are characterized and the data are compared to appropriate theories to determine ionization energy values for the dominant traps. In n-type, trap energy levels of Ec - 0.38 ± 0.03 and Ec - 0.46 ± 0.03 eV are obtained, and in p-type an energy level of Ev + 0.29 ± 0.03 eV is observed.