Radiation effects in silicon-on-insulator transistors with back-gate control method fabricated with OKI Semiconductor 0.20 μm FD-SOI technology

Bonded silicon-on-insulator (SOI) wafers have the capability of realizing monolithic pixel devices, where the silicon resistivity is optimized separately for the electronics and detector parts. Using UNIBOND wafers, we are developing monolithic pixel devices fabricated with OKI Semiconductor 0.20 μm FD-SOI technology. A set of PMOS and NMOS transistors were irradiated with protons in order to investigate the total ionization dose effect in transistor operation. We evaluated also the devices with a back-gate control electrode added underneath the buried oxide layer. Primary radiation effect appears in transistor threshold shifts, which can be explained by charge traps in the oxide layers and charge states created at the silicon–oxide boundaries. We discuss the possibility of TCAD simulation for evaluation of the charge densities.