Total ionization damage effects in double silicon-on-Insulator devices

We are developing monolithic pixel sensors based on a 0.2 μm fully-depleted silicon-on-Insulator (SOI) technology. The major issue in applications them in high-radiation environments is the total ionization damage (TID) effects. The effects are rather substantial in the SOI devices since the transistors are enclosed in the oxide layers where generated holes are trapped and affect the operation of the near-by transistors. The double SOI sensors that provide an independent electrode underneath the buried oxide layer have been developed. We have irradiated transistor test elements and pixel sensors with γ-rays. By adjusting the potential of this electrode, the TID effects are shown to be compensated. The pixel sensor irradiated to 20 kGy recovered its functionality by applying a bias to the electrode. The radiation tolerance of the SOI devices has been substantially improved by the double SOI.