The existence of buried oxide (BOX) layer and the strong coupling effect between the front and back channels can worsen the radiation-induced degradation on fully depleted silicon-on-insulator (FDSOI) device. To mitigate the radiation impact, a new structure named double SOI is introduced in this paper. This new structure exhibits potential benefits of reducing the radiation-induced degradation effectively and independently, thanks to the additional electrode, which can be used to control the internal electrical field of the BOX layer. With this structure, FDSOI device parameter degradation due to total dose is studied, and some abnormal phenomena, such as the transconductance hump and the mobility enhancement, are observed and discussed. Sentaurus TCAD simulations are used for further analysis. Moreover, the impact of negative back-gate bias to transistor parameter degradation is investigated, and an improved back-gate compensation strategy is proposed. Technology improvement such as thinning the BOX on total ionizing dose (TID) amelioration is also discussed with TCAD simulation.

A new characterization of control Lyapunov functions is presented for non-linear systems with structural uncertainty. Based on this characterization, we deal with the problem of globally asymptotical stabilization of two classes of non-linear systems with structural uncertainty. Sufficient conditions for the globally asymptotical stabilization of the closed-loop system are acquired respectively. In addition, state feedback control laws are designed respectively to globally asymptotically stabilize the equilibrium of the closed-loop system. Finally, the simulations show the effectiveness of the method.

This work proposes Total Ionizing Dose (TID) hardening techniques compatible with conventional 14-nm-node silicon-on-insulator (SOI) FinFETsf process flows through performing 3-dimensional (3-D) simulations based on technology computer-aided design (TCAD) tools. The simulation results reveal a significantly critical TID impact induced by trapped charges in the buried oxide (BOX) and the spacer with calibration against 14 nm SOI FinFETfs experimental data (error < 6%). Inspired by the physical interpretation, an optimization technique featuring an optimized gate structure, spacer length, and substrate bias is designed. The optimized gate structure is utilized to enhance the local gate-to-channel coupling at the bottom and reduce the generation and capture of electron-hole pairs. By reducing the spacer length, a lower sensitive volume in the spacer can effectively suppress the TID response. The setting of the negative substrate bias greatly improves the subthreshold characteristics, weakening the TID effect in the BOX. By adopting the combined optimization including these techniques, the threshold voltage shift (VTH) induced by a 5 Mrad(SiO2) irradiation can be reduced to 21 mV, whereas VTH is 45 mV with only gate structure optimized and 97 mV without hardening. Meanwhile, the ION/IOFF after radiation increases to 1 × 107, which is at least four orders of magnitude better than the original device. Meanwhile, subthreshold swing (SS) is reduced from 81 mV/dec to 71 mV/dec, and Drain Induced Barrier Lowering (DIBL) is reduced from 120 mV/V to 99 mV/V, respectively. The combined optimization design is demonstrated as an effective method to improve the tolerance against TID irradiation without compromising performance, promoting 14 nm SOI FinFET’s application in future harsh space environments.

This paper presents a 19 ps precision and 170 M samples/s time-to-digital converter (TDC) in FPGA. Through the direct count method and tapped delay line method, the coarse count and fine count can be extracted, respectively. The direct count is realized by the 350 M clock and the tapped delay line is constructed by the CARRY4 block. The ones-counter encoder is used to convert the thermometer code with bubble errors into binary code, which is applicable to all the FPGA chips. This work not only explains the schematic of the ones-counter encoder, but also shows how to configure it. Owing to the inconsistency of delay elements caused by process, bin-by-bin calibration is utilized to improve the differential nonlinearities (DNL) and integral nonlinearities (INL) of the TDC. A novel method was developed to compensate the influence of voltage and temperature. As the delay elements vary with voltage and temperature, a frequency counter is used to extrapolate and compensate its effect on the delay line. All of the above strategies use online calibration and improve the precision and sampling rate of TDC. The experimental results show the least significant bit (LSB) achieves 17.4 ps, the DNL is within [−0.90, 1.67] LSB, and the INL is in the range of [−1.90, 3.31] LSB.

The effects of proton irradiation on the electrical and optical properties of hybrid perovskite photodetectors have been investigated in this paper. Our results reveal that no significant changes in the photoelectric properties of the perovskite photodetectors are observed when the proton fluence accumulates to 1 × 10¹² p cm⁻². However, with further increase of proton fluence, the photoelectric conversion efficiency of the perovskite photodetectors begins to decrease notably. This can be attributed to the introduction of deep defect levels within the bandgaps of the CH₃NH₃PbI₃ active layer and the phenyl-C61-butyric acid methyl ester (PCBM) layer after proton irradiation. Based on time-resolved photoluminescence measurements, the deep defect levels in the active layer behave as nonradiative recombination centers, resulting in a reduction of carrier lifetime. According to our first-principles calculations, the deep defect levels in the PCBM layer act as electron trap centers, leading to an accumulation of photo-generated electrons. Most interestingly, when the proton fluence reaches 1 × 10¹⁴ p cm⁻², a transient inverse current in the perovskite photodetectors is observed after stopping illumination. This abnormal phenomenon is due to the accumulation and release of electrons trapped in the PCBM layer, which can diffuse to the perovskite active layer and form the inverse current.