To enable precise application of back-gate biasing for radiation hardening in double silicon-on-insulator (DSOI) technology, it is essential to evaluate the variation in total ionizing dose (TID) response under different channel size conditions. This article investigates the influence of channel sizes on TID response in H-gate DSOI nMOSFETs. The experimental results indicate that shorter-channel devices exhibit higher TID sensitivity at low-to-medium doses but demonstrate a significant threshold voltage rebound at high doses. Furthermore, under short-channel conditions, increasing the channel width aggravates degradation, resulting in an anomalous radiation-induced wide channel effect (RIWCE). The 3-D TCAD simulation is carried out to further analyze the size-dependent phenomena. Simulation results highlight that channel sizes modulate the local electric field distribution within the buried oxide (BOX), thereby influencing the density and spatial evolution of radiation-induced trapped charges. Finally, charge extraction via the mid-gap and DCIV techniques confirms the differences in trapped charge density and provides a mechanistic explanation for the rebound effect.

This work proposes a modeling methodology for simulating total ionizing dose (TID) effects in bulk FinFETs. The primary objective is to achieve congruence between the simulated I-D-V-G curves and experimental results under multiple conditions. Based on a model capable of reproducing the electrical characteristics of the device before irradiation, further calibrating defect-related parameters and source/drain depth that affect the model's accuracy under multiple bias conditions enables a closer match between the simulation results and the postirradiation experimental data. The simulated preirradiation I-D-V-G curves were calibrated through systematic optimization of the channel length, doping profiles, work function, and source/drain series resistance. For postirradiation characteristics, the accuracy of the model was improved by adjusting the density of oxide-trapped charges and interface traps, along with the distribution of interface traps and the source/drain depth. The I-D-V-G curves measured at multiple drain biases were employed to calibrate the model, enabling the final simulation results to become as close as possible to the characteristics of the practical device.

This paper investigates the impact of heavy ion irradiation on the inverse piezoelectric effect in p-GaN HEMT devices. Heavy ion irradiation introduces donor-type defects in the p-GaN layer and acceptor-type defects in the AlGaN barrier and at the AlGaN/GaN interface, leading to a positive shift in threshold voltage (Vth), reduced transconductance (Gm), and increased on-resistance (RDS(on)). During subsequent inverse piezoelectric stress, the pre-existing donor-type defects locally modulate the electric field distribution, resulting in a lower electric field strength acting on the barrier layer in the irradiated devices compared to the unirradiated ones. This leads to a reduction in the generation of acceptor defects during the inverse piezoelectric process, and finally the parameters variations in irradiated devices after the inverse piezoelectric test is smaller than that subjected solely to the inverse piezoelectric effect.

The total ionizing dose (TID) response variability of SiC NMOSFETs in the same batch was studied in this paper through gamma-ray irradiation and annealing test. Experiments show that the devices exhibit significant radiation damage, and the parameters partially recover after room temperature annealing, and completely recover after high temperature annealing. The variability of threshold voltage and subthreshold swing increases after irradiation and decreases after annealing. However, the variability of saturation drain current decreases with irradiation and increases with annealing, while the variability of maximum transconductance is almost unchanged. The oxide trapped charges and interface traps are generated during irradiation and recover to near the initial value during high temperature annealing. The change of parameters variability after irradiation and annealing results from the variability of trapped charges induced by irradiation.

In this article, the interaction of total ionizing dose (TID) effect and hot carrier injection (HCI) degradation in bulk I/O-FIN field-effect transistors (FinFETs) is investigated. The results for stress post radiation (SPR) show that the HCI degradation of irradiated devices is greater than that of unirradiated, and the irradiated devices undergo rapid recovery by HCI stress for a very short time. With the increase of stress time, the influence of TID on HCI decreases and the OFF-state leakage current after irradiation does not recover to the initial value of the device. The electrons injection into the shallow trench isolation (STI) during HCI is suggested as the reason for parameters recovery after irradiation. While the experiment results of radiation post stress (RPS) show that there is no obvious influence of HCI on TID, since there is no electrons injection into STI region during HCI before TID. The irradiation experiment under HCI bias shows that the combination of these two effects causes the change of device characteristics. The mechanism of interaction between TID and HCI is revealed.

Position-sensitive photodetectors (PSDs) have been widely used for seamless, high-resolution light tracking, but applications such as aerospace and prolonged field operations require stable performance in extreme environments. Conventional PSDs, typically based on the lateral photovoltaic effect of silicon or other semiconductor junctions, are prone to radiation damage and material degradation, limiting their reliability under harsh conditions. Silicon carbide (SiC), with its wide bandgap, high mobility, low defect density, and strong resistance to radiation damage, offers a promising alternative for developing robust detectors. In this work, we present a PSD based on undoped 4H-SiC, designed with a simple vertical structure that eliminates the need for complex multi-interface architectures. The device demonstrates excellent performance, including a light on-off ratio exceeding 103 under sub-milliwatt illumination, spatial resolution of ∼0.1 μm, and fast response times of ∼10 μs (rise) and ∼6.3 μs (fall). It also exhibits remarkable stability under γ-ray irradiation (300 krad) with minimal photocurrent variation, making it suitable for accurate position tracking in radiation-prone environments. This work highlights the potential of 4H-SiC-based PSDs for advanced sensing applications that demand both high performance and resilience in extreme environments.

Carbon nanotube (CNT)-based devices and circuits exhibit inherent radiation tolerance, making them promising candidates for harsh environment applications. Examining device characteristics under bias conditions is essential for practical applications. This work investigates total ionizing dose (TID) effects on CNT field effect transistor (CNTFET) and static random access memory (SRAM) performance under various bias conditions. Both transistor I-DS - V-GS characteristics and SRAM static noise margin (SNM) are evaluated. Experimental results reveal that CNTFET threshold voltage ( V-th ) shifts strongly depend on irradiation bias conditions. SNM degradation is more severe under biased conditions than under floating conditions. The V(th )shifts result from the synergistic effects of bias stress and irradiation, with interface traps and oxide trapped charges in the passivation layer playing dominant roles. Different bias conditions cause varying degrees of transistor degradation within SRAM cells, resulting in SNM variations. Optimizing passivation processes is crucial for mitigating interface traps formation and enhancing device reliability under irradiation, thereby advancing carbon-based circuit applications.

This work investigates the total ionizing dose (TID) response of 16-nm bulk n -fin field-effect transistor (FinFET) under different substrate biases after irradiation. Experiments demonstrate that applying a negative substrate bias after irradiation significantly mitigates the TID-induced off-state current ( I (off) ) and results in a slight positive shift in the threshold voltage ( V-th ). Technology computer-aided design (TCAD) simulation reveals that the response of these two parameters is attributed to the reduction in electron density under negative substrate bias. We further elucidated the physical mechanism of the disparate response extents exhibited by V-th and I (off) under an identical substrate bias. At low gate voltage conditions, the application of negative substrate bias effectively reduces the electron density in the sub-fin region, resulting in a pronounced reduction of the off-state current. As the gate voltage increases, the peak of the electron density gradually shifts toward the channel. When the gate voltage approaches the threshold voltage, a new parasitic leakage path emerges. Within this path, the electron density remains almost unaffected by the substrate voltage, resulting in an insignificant threshold voltage shift.

The electrical behavior of 22-nm ultrathin body and buried oxide fully depleted silicon on insulator (UTBB FD-SOI) MOSFETs has been investigated up to a total ionizing dose (TID) radiation of 100 Mrad(Si). At high TID levels, the radiation-induced parameter degradation of test devices is obvious. By exploring the channel length and width dependence, we demonstrate that the high TID effect of UTBB FD-SOI devices is mainly governed by trapped charges in buried oxides (BOX) layer, and TID effects in shallow trench isolation (STI) and spacer oxide are negligible. Furthermore, the TID radiation-induced drain bias induce barrier lowering (DIBL) effect in UTBB FD-SOI nMOSFETs is also observed, which limits the radiation tolerance of devices in the saturation region. Finally, based on technology computer aided design (TCAD) simulations, the related mechanisms for subthreshold slope degradation and radiation-induced DIBL effect of UTBB FD-SOI technology are proposed, respectively.

In this paper, we investigated an experimental analysis of the degradation caused by low dose rate irradiation in GaN-based high-electron-mobility transistors (HEMTs) with a p-type gate. Combined with experimental frequency-dependent conductance ( G(p)/omega) analyses and TCAD simulations, it has been demonstrated that the negative shifts in both I-d - V-gs and V-th are primarily due to the formation of donor-like traps near the p-GaN/AlGaN interface, which is a result of the dehydrogenation of pre-existing defects during low dose rate irradiation. Additionally, the results of the TCAD simulations, indicate that the trap-assisted tunneling (TAT) process, which involves the recombination of trap-assisted holes with electrons in the p-GaN layer, may dominate the physical mechanisms responsible for the increase in gate leakage current ( I-g -V-gs ). These results may provide a basis for understanding the role of radiation-induced traps on electrical parameters degradations for p-GaN gate HEMTs.

Impact of total ionizing dose (TID) Irradiation on Static Noise Margin (SNM) of 22nm Ultra-Thin Body and Buried oxide Fully Depleted Silicon-On-Insulator (UTBB FD-SOI) 6-T static random access memory (SRAM) Cells is investigated in this paper. TID effect on SNM was measured by the single SRAM cell test structure allowing precise measurement of cell SNM under hold, read and write modes. Experimental results show that SNM of 22nm UTBB FD-SOI SRAM cell is significantly decreased by TID. And, read SNM is more vulnerable to irradiation, even to be lowered down 0mV at 500krad(Si), leading to the read functionality failure. The bias-dependent TID induced threshold voltage shift is responsible for the significant SNM decrease. Moreover, TID effect on SNM including transistor-to-transistor variation caused by within-die process and TID damage variability is explored by Monte Carlo simulation, illustrating that TID effect on SNM will be underestimated by measurement of limited number of SRAM cells.

Total ionizing dose (TID) response of 16-nm core and input-output (I/O) n-type fin field-effect transistors (n-FinFETs) with various gate lengths and fin numbers are investigated in this study. The TID sensitivity of I/O n-FinFETs is much higher than that of core devices. The reverse breakdown voltage measurement of drain-bulk junction indicates that I/O n-FinFETs have a lower doping concentration in the channel stop region compared with core devices. The low doping concentration is considered as the root cause of the high TID sensitivity of I/O n-FinFETs. Technology computer-aided design (TCAD) simulation is used to analyze the influence of ion implantation process on doping distribution of the channel stop region, as well as the TID response under different ion implantation process conditions. Known from the simulation, when increasing the doping concentration in upper area of channel stop by adjusting the ion implantation parameters, the TID damage can be effectively suppressed.

The total ionizing dose (TID) effect on MOSFETs, which use the Bipolar-CMOS-DMOS (BCD) technology, is investigated under different gate biases utilizing X-rays. The threshold voltage, maximum transconductance and subthreshold swing of the device before and after irradiation were obtained. The results indicate that the TID effect is significantly influenced by gate bias. For NMOSFET, the maximum threshold voltage shift occurs at a positive gate bias of 3 V. For PMOSFET, the minimum threshold voltage shift occurs at a negative gate bias of -3 V. The mechanism was revealed to be the result of the combined effects of initial recombination, hole capture, and electron tunneling processes. However, the case of PMOSFET differs from NMOSFET due to the disappearance of electron tunneling and the change in the direction of hole movement under negative gate bias.

In this letter, total ionizing dose (TID) response of bulk n-type Fin Field-Effect Transistor (n-FinFET) is investigated with the various number of fins. Experiments show that only the single fin n-FinFET exhibits significant radiation damage, while the degradation of multi-fin devices is observed to be minimal. 3D TCAD simulations indicate that relative positions between fins and STI play a critical role in the TID response of n-FinFET.

The excellent performance and radiation-hardness potential of carbon nanotube (CNT) field effect transistors (CNTFETs) have attracted wide attention. However, top-gate structure CNTFETs, which are often used to make high-performance devices, have not been studied enough. In this paper, the total ionizing dose (TID) effect of the top-gate structure CNTFETs and the influence of the substrate on top-gate during irradiation are studied. The parameter degradation caused by the irradiation- and radiation-damage mechanisms of the top-gate P-type CNTFET were obtained by performing a Co-60 γ-ray irradiation test. The results indicate that the transfer curves of the top-gate P-type CNTFETs shift negatively, the threshold voltage and the transconductance decrease when TID increases, and the subthreshold swing decreases first and then increases with the increase in TID. The back-gate transistor is constructed by using the substrate as a back-gate, and the influence of back-gate bias on the characteristics of the top-gate transistor is tested. We also test the influence of TID irradiation on the characteristics of back-gate transistors, and reveal the effect of trapped charge introduced by radiation on the characteristics of top-gate transistors. In addition, the CNTFETs that we used have obvious hysteresis characteristics. After irradiation, the radiation-induced trapped charges generated in oxide and the OH groups generated by ionization of the CNT adsorbates aggravate the hysteresis characteristics of CNTFET, and the hysteresis window increases with the increase in TID.

当前,汽车照明及投影除了有基础提示和警示作用之外,越来越成为汽车品牌差异化设计的重要元素和新显示语言.汽车投影灯在创造独特氛围的同时亦能增强车与车、车与人的交流互动性,是各大车企在智能汽车时代提升用户感知度、打造新颖互动驾乘体验的优选设计.本文主要基于在汽车上采用MLA技术的汽车投影灯,对小型化、范围大、亮度高和轮廓清晰等主要优点进行阐述,并对汽车MLA投影技术的应用进行介绍.相比传统投影,MLA投影技术将是车载投影的热门技术,未来与之相关的应用将更广泛.

Silicon-based vertical double-diffused MOSFET (VDMOS) devices are important components of the power system of spacecraft. However, VDMOS is sensitive to the total ionizing dose (TID) effect and may have TID response variability. The within-batch TID response variability on silicon-based VDMOS devices is studied by the 60Co gamma-ray irradiation experiment in this paper. The variations in device parameters after irradiation is obtained, and the damage mechanism is revealed. Experimental results show that the standard deviations of threshold voltage, subthreshold swing, output capacitance, and diode forward voltage increase, while the standard deviation of maximum transconductance decreases after irradiation. The standard deviation of on-state resistance is basically unchanged before and after irradiation. By separating the trapped charges generated by TID irradiation, it is found that the deviation of the oxide trapped charges and the interface traps increase with the increase in the total dose. The reasons for the variation in device parameters after irradiation are revealed by establishing the relationship between the trapped charges and the electrical parameters before and after irradiation.

针对纳米金属-氧化物-半导体(MOS)器件中采用的高介电常数HfO2栅介质,开展电离总剂量效应对栅介质经时击穿特性影响的研究.以HfO2栅介质MOS电容为研究对象,进行不同栅极偏置条件下60Co-γ射线的电离总剂量辐照试验,对比辐照前后MOS电容的电流-电压、电容-电压以及经时击穿特性的测试结果.结果显示,不同的辐照偏置条件下,MOS电容的损伤特性不同.正偏辐照下,低栅压下的栅电流显著增大,电容电压特性的斜率降低;零偏辐照下,正向高栅压时栅电流和电容均显著增大;负偏辐照下,栅电流均有增大,正向高栅压下电容增大,且电容斜率降低.3种偏置下,电容的经时击穿电压均显著减小.该研究为纳米MOS器件在辐射环境下的长期可靠性研究提供了参考.

The effects of 10 MeV proton irradiation on the threshold voltage and gate oxide reliability of SiC MOSFET are investigated. The negative shift of the threshold voltage was observed after irradiation, and the magnitude of the shift is exclusively related to the fluence and not the drain voltage. Moreover, proton irradiation leads up to the degeneration of oxide reliability. Experiment and simulation results indicate that the shift of the threshold voltage is caused by the total ionizing dose effect. Due to the superior blocking capabilities of the SiC MOSFET, the electric field of gate oxide is almost unaffected by the voltage applied to the drain, so the drift of threshold voltage is only related to particle fluence. The single event effect is responsible for the degradation of gate oxide reliability. The single event effect induces a transient high electric field in the gate oxide, which generates defects and affects the reliability of the gate oxide.

对总剂量辐射环境下不同偏置状态的碳化硅功率场效应管(SiC VDMOS)的动态特性进行了相关研究.在比较3种偏置状态下60 Coγ射线辐照对于SiC VDMOS器件阈值电压和开关特性影响的基础上,进行了室温退火试验.结果表明,随60 Coγ射线辐照剂量的增加,氧化层积累陷阱电荷,导致静态特性中阈值电压降低.同时器件动态特性中开启时间略微缩短,关断时间骤增,开关损耗增大.器件受辐照后耗尽层厚度和阈值电压发生的变化是其开启和关断响应差异性退化的主要原因.