Total Ionizing Dose Radiation Effects in Al2O3-Gated Ultra-Thin Body In0.7Ga0.3As MOSFETs

We have investigated total ionizing dose (TID) radiation effects in Al2O3-gated ultra-thin body In0.7Ga0.3As MOSFETs. A non-monotonic dependence of the threshold voltage (Vth) on the X-ray radiation dose was observed and analyzed; the accompanying degradation in subthreshold swing (SS) likely is caused by non-uniform trapped charge in the near-interfacial Al2O3 rather than interface-trap generation. The off-current and gate breakdown voltage were independent of dose up to 6 Mrad(SiO2). Compared to the InP-free device, the device with an InP barrier is more vulnerable to TID effects in terms of Vth shift, SS, and mobility degradation.