Total Ionizing Dose Effects Research Articles

Total Ionizing Dose Effects on Physical Unclonable Function From NAND Flash Memory

This article demonstrates the total ionizing dose (TID) impact on a NAND flash memory-based physical unclonable function (PUF). We used commercial-off-the-shelf flash memory chips to generate PUF. The flash chip is irradiated with Co-60 gamma rays up to 10 krad(Si). The irradiated chip shows significant accuracy degradation (bit error ~ 12%) of the flash-PUF. We show that TID-induced trapped charges in the oxide alter the intrinsic cell properties causing accuracy degradation of flash-PUF. We propose two independent techniques to improve the PUF accuracy under radiation environment. The first technique relies on electrical annealing which compensates the trapped charges by program stressing. The second technique uses radiation compensation method by adaptive PUF generation process. Our experimental results show that the accuracy degradation can be as low as 1.5% for TID up to 10 krad(Si) with these radiation mitigation techniques.

Analysis of Bipolar Integrated Circuit Degradation Mechanisms Against Combined TID–DD Effects

Integrated circuits sensitive to both total ionizing dose (TID) and displacement damage (DD) effects can exhibit degradation profiles resulting from a combination of degradation mechanisms induced by both effects. This work presents circuit simulations based on experimental data to explain degradation mechanisms induced by combined TID and DD effects on a bipolar IC current source. First, the effect of the degradation of each internal transistor on the circuit's response is evaluated by applying electrical parametric changes. Then simulations are performed from different degradation scenarios based on observed circuit behaviors to reproduce the different TID, DD, and combined TID-DD responses. These simulations show that a synergistic interaction between a current leakage induced by DD on a transistor located in the bandgap reference part with the gain degradation of a current mirror induced by both TID and DD appears to be responsible for the combined TID-DD response. It is also shown that the circuit degradation rate depends on the DDD/TID rate ratios encountered during the exposition.

Total ionizing dose effects on nanosheet and nanowire field effect transistors

Total ionizing dose (TID) effects are investigated in a nanosheet gate-all-around field effect transistor using three-dimensional technology computer aided design simulation. TID is a reliability concern in terms of building up trap charges in any dielectric surrounding the transistor body. In this work, the impact of trap charges on different dielectrics including gate oxide, gate spacer and shallow trench isolation is discussed. The TID vulnerabilities for various channel characteristics are compared. Methods for suppressing the manifestation of trap charges are suggested.

Total Ionizing Dose Effects on Multistate HfOₓ-Based RRAM Synaptic Array

Emerging nonvolatile memories (eNVMs) have demonstrated satisfactory accuracy on various applications in deep learning. Characterized by high density and low leakage power consumption, resistive random access memory (RRAM) becomes very attractive in synaptic devices for deep neural networks (DNNs). RRAM-based synaptic devices include both analog and discrete versions. Unlike analog RRAM synapses which suffer from nonlinearity, discrete but multistate RRAM synapses are better suited for neural network hardware implementation. In this article, the multistate operation in RRAM arrays has been proposed as a synaptic device for DNN inference. Four-state conductance has been achieved in HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> -based RRAM synaptic arrays. The impact of total ionizing dose (TID) on the multistate behavior of HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> -based RRAM is investigated by irradiating a one-transistor-one-resistor (1T1R) 64-kb array with CMOS peripheral decoding circuitry fabricated at the 90-nm technology node with Co-60 gamma rays ( <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">60</sup> Co γ-ray irradiation).

TID Effects Induced by ARACOR, 60Co, and ORIATRON Photon Sources in MOS Devices: Impact of Geometry and Materials

Total ionizing dose (TID) effects induced by different photon sources are studied in MOS devices. The dose factor (DF), defined as the ratio between dose deposition in dosimeter and actual dose deposition in MOS-sensitive oxides (SOs), is estimated using Monte-Carlo simulations of energetic photons striking simple device structures. An effective TID approach is proposed to account for both the real ionizing dose depositions in small volumes and the charge yield. This method is applied to a silicon-on-insulator (SOI) technology using three photon sources: the usual ARACOR and <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">60</sup> Co sources, which deliver several tens of kiloelectron volt photons and ~1.25-MeV photons, respectively, and a third facility named ORIATRON, a 6-MeV electron linear accelerator that produces photons on a wide energy spectrum. This topic, investigated intensively in the literature a few decades ago, is revisited in the context of several evolutions including: new radiation sources, novel simulation tools, and device scaling, which all impact ionizing dose deposition in microsensitive volumes of current electronic technologies. Dedicated numerical simulations demonstrate the importance of taking into account the entire stack of materials in order to get the most accurate estimations of TID in the SO. Descriptions of the back-end-of-line (BEOL) layers (especially when the technology uses copper), the polysilicon gate, the Buried OXide (BOX) (for SOI devices), but also of the substrate and package are mandatory in these simulations, since dose enhancement and/or backscattered photons can be a significant source of TID variation in the gate oxide. Also the package lid composition and its thickness can be major TID contributors. The results show that the use of a prefilter with lead and aluminum can optimize ionizing dose deposition

Radiation hardened H-diamond MOSFET (RADDFET) operating after 1 MGy irradiation

Although the surface conductivity of a hydrogen-terminated diamond (H-diamond) enables production of high-performance field effect transistors (FETs), the total ionizing dose effect is yet to be clarified for H-diamond FETs. We fabricated a RADiation hardened H-terminated Diamond metal–oxide–semiconductor FET (RADDFET) using an oxide gate dielectric deposited at high temperatures. This paper describes its stable operation after 1 MGy irradiation. H-diamond films were prepared using microwave plasma assisted chemical vapor deposition with a p+ layer for reduction of contact resistance. The Al2O3 passivation layer was deposited by atomic layer deposition at 450 °C to achieve operation in high-temperature environment; then a RADDFET was fabricated on them using a Ru electrode. Several current–voltage characteristics were compared before irradiation and after certain dose levels up to 1 MGy. Before they were irradiated in air, the dose rate was measured using a cellulose triacetate film dosimeter. Even after an irradiation level of 1 MGy, the off-current at gate bias voltage (VG) of 3 V was more than six orders of magnitude lower than the on-current at VG of −6 V. Variation of the drain current density (JDS) in the measurements was less than 2%. The threshold voltage shifted approximately 1.7 V with 3 kGy of x ray irradiation, but no marked degradation was confirmed at higher levels. The subthreshold swings were 238, 215, and 264 mV/decade, respectively, after irradiation of 100 kGy, 300 kGy, and 1 MGy. These results indicate that the RADDFET was very stable at higher doses after initial stabilization.

TID Circuit Simulation in Nanowire FETs and Nanosheet FETs

In this study, the effects of the total ionizing dose (TID) on a nanowire (NW) field-effect transistor (FET) and a nanosheet (NS) FET were analyzed. The devices have Gate-all-around (GAA) structure that are less affected by TID effects because GAA structures have better gate controllability than previously proposed structures, such as planar MOSFETs and FinFETs. However, even for GAA devices with the same channel cross-sectional area and equivalent oxide thickness, structural differences can exist, which can result in different tolerances of TID effects. To observe the device and circuit operation characteristics of these GAA devices with structural differences, n-type and p-type devices were designed and simulated. The circuit simulation according to TID effects was conducted using Berkeley short-channel insulated-gate FET model (BSIM) common multi-gate (CMG) parameters. The NS-FET generated more VT shift than the NW-FET because the NS-FET had a wider gate oxide area and channel circumference, resulting in more interface hole traps. The abnormal VT shift leads to causing unstable circuit operation and delays. Therefore, it was confirmed that the ability of the NW-FET to tolerate TID effects was better than that of the NS-FET.

Investigating Heavy-Ion Effects on 14-nm Process FinFETs: Displacement Damage Versus Total Ionizing Dose

Bulk 14-nm FinFET technology was irradiated in a heavy-ion environment (42-MeV Si ions) to study the possibility of displacement damage (DD) in scaled technology devices, resulting in drive current degradation with increased cumulative fluence. These devices were also exposed to an electron beam, proton beam, and cobalt-60 source (gamma radiation) to further elucidate the physics of the device response. Annealing measurements show minimal to no “rebound” in the ON-state current back to its initial high value; however, the OFF-state current “rebound” was significant for gamma radiation environments. Low-temperature experiments of the heavy-ion-irradiated devices reveal increased defect concentration as the result for mobility degradation with increased fluence. Furthermore, the subthreshold slope (SS) temperature dependence uncovers a possible mechanism of increased defect bulk traps contributing to tunneling at low temperatures. Simulation work in Silvaco technology computer-aided design (TCAD) suggests that the increased OFF-state current is a total ionizing dose (TID) effect due to oxide traps in the shallow trench isolation (STI). The significant SS elongation and ON-state current degradation could only be produced when bulk traps in the channel were added. Heavy-ion irradiation on bulk 14-nm FinFETs was found to be a combination of TID and DD effects.

Improving TID Radiation Robustness of a CMOS OxRAM-Based Neuron Circuit by Using Enclosed Layout Transistors

Aerospace applications are attractive candidates to embed artificial neural networks despite their excellent parallel processing capability and reduced energy consumption. Nonetheless, the long-term exposure to incidence levels of ionizing radiation may degrade their physical components reducing, therefore, their reliability and expected lifetime. Thus, it is mandatory to face the challenge of enhancing the radiation hardening characteristics of a neural circuit before operating in harsh environments. A possible solution to substantially reduce long-term spurious effects caused by ionizing radiation [referred to as total ionizing dose (TID)] is to change the conventional rectangular MOS gate geometry to a nonstandard topology referred to as an enclosed layout transistor (ELT). In the context of hardening a complete neuron circuit against TID effects, together with the well-established ELT paradigm, it is possible to exploit the inclusion of other hardened devices, for instance, the memory element. In this sense, the Oxide-based Resistive Random Access Memory (OxRAM) can be used as the memory element, which is inherently tolerant against ionizing radiation and, hence, better suited for a fully hardened circuit. In this work, we propose to harden the design of an existing OxRAM-based neuron circuit through the inclusion of ELTs, i.e., to improve the radiation hardening characteristics of a preexistent convenient neuron circuit topology by using the enclosed gate geometry for the nMOS and pMOS devices. Electrical simulations, considering a standard commercial bulk CMOS fabrication process, in a 180-nm technology, have been carried out to validate our proposed design. In addition, we exploit two simulation setups: first, the OxRAM's behavior in a simple circuit configuration, to provide a better understanding of the OxRAM device; second, the OxRAM-based neuron circuit, to evaluate the behavior of the proposed neuron circuit hardened with ELTs. The simulation results, supported by the analysis of former works regarding the incidence of ionizing radiation in OxRAM and ELTs, indicate that the proposed hardened neuron circuit is a feasible solution to embed neuromorphic computing in aerospace applications.

Radiation-Hardened Cortex-R4F System-on-Chip Prototype With Total Ionizing Dose Dynamic Compensation in 28-nm FD-SOI

This article presents a radiation-hardened Cortex-R4F system-on-chip prototype with integrated total ionizing dose (TID) dynamic compensation capabilities, designed and fabricated in 28-nm fully depleted silicon-on-insulator (FD-SOI) technology. The processor was made robust to single-event effects, thanks to several design techniques: error correcting code (ECC) protected and bit-interleaved memories, optimized radiation-hardened sequential cells, and sensitive logic cells filtering. To counter the TID effects on the processor functionality and performances, the system embeds an integrated digital dosimeter. The dosimeter is capable of computing the TID in real time and providing the information to the system. Using a software lookup table (LUT), coupled with 28-nm FD-SOI technology support of asymmetric and wide-body-biasing, the reported TID can be converted to a request made to an external body-bias generator and be fully compensated. The system, operating at 0.9 V and 500 MHz, was tested under space grade radiations and has shown no failure in the 0 krad(Si) to 50 krad(Si) TID range.

Total ionizing dose effects in junctionless accumulation mode MOSFET

In this paper, an extensive investigation of low-frequency (1/f) noise and total ionizing dose–response of junctionless accumulation mode double-gate (JAM DG) MOSFET is presented. Current–voltage (Id–Vg) characteristics and low-frequency noise of JAM DG MOSFET are simulated at different ionized doses and compared to different gate oxide thickness and different channel doping concentrations. A significant amount of irradiation-induced threshold voltage shift and increase in low-frequency noise is observed for different gate oxide thickness and channel doping concentration. Moreover, the irradiation-induced border trap densities are also obtained at different doses. The gamma radiation model of Sentaurus TCAD is used to get the required results.

Total ionizing dose effects of 60Co-γ ray radiation on the resistive switching and its bending performance of Al-in-O/InOx-based flexible RRAM device

Flexible resistive switching random access memory (RRAM) device is one of the promising candidates for non-volatile memory used in space because of its features such as simple structure, high speed, low power consumption, durability and lightweight with reduction in thickness. Al-In-O/InOx self-mixing layer can be applied for flexible RRAM due to its low annealing temperature (i.e. temperatures<180 °C), forming-free resistive switching characteristics and low SET and RESET voltage. Herein, effects of the total ionizing dose of 60Co-γ ray radiation on the resistive switching, the bending performance of the prepared flexible RRAM devices based on the Al-In-O/InOx films were studied. The results indicated that the resistance decreases with the bias in high resistance state (HRS) and the SET voltages of the device decrease very slightly after irradiation, while the low resistance state (LRS), RESET voltage, and retention parameters are almost immune to radiation. Moreover, after irradiation, the decrease of resistance with the bias in HRS becomes more exacerbated when bended. Mechanism of bending on the RS is studied by the first-principles calculation, and the mechanism underlying the irradiation effect is studied from the viewpoint of the origin of RS.

Analysis of Circuit Simulation Considering Total Ionizing Dose Effects on FinFET and Nanowire FET

In this study, we analyzed the total ionizing dose (TID) effect characteristics of p-type FinFET and Nanowire FET (NW-FET) according to the structural aspect through comparison of the two devices. Similar to n-type devices, p-type NW-FETs are less affected than FinFETs by the TID effect. For the inverter TID circuit simulation, both n- and p-types of FinFET and NW-FET were analyzed regarding the TID effect. The inverter operation considering the TID effect was verified using the Berkeley short-channel insulated-gate FET model (BSIM) common multi-gate (CMG) parameters. In addition, an inverter circuit composed of the NW-FET exhibited a smaller change by the TID than that of an inverter circuit composed of the FinFET. Therefore, the gate controllability of the gate-all-around (GAA) device had an excellent tolerance to not only short-channel effects (SCE) but also TID effects.

Influence of Buried Oxide Si+ Implantation on TID and NBTI Effects for PDSOI MOSFETs

The total ionization dose (TID) effect and negative bias temperature instability (NBTI) effect of 130-nm partially-depleted silicon-on-insulator (PDSOI) MOSFETs fabricated on hardened wafers with silicon ion implantation and unhardened wafers are investigated. A TID-hardened PDSOI MOSFET up to 1 Mrad(Si) is obtained by Si+ implantation in buried oxide (BOX). The hardening benefits from the electron traps in the BOX introduced by Si+ implantation. Although the radiation hardening process has a rare impact on nominal electrical characteristics of the device before irradiation, it will affect the NBTI reliability, which is manifested as the decrease in the NBTI lifetime for the radiation-hardened devices. The energy distribution of positive charges built up during NBTI stress is obtained. It proves that more damage-related traps exist near the gate oxide/silicon interface for the radiation-hardened device, which accelerates the threshold voltage shift during the NBTI stress. This conclusion is also verified by the low-frequency noise characteristics.

Single event effect and total dose effect of GaN high electron mobility transistor using heavy ions and gamma rays

The single event effect (SEE) and the total ionizing dose (TID) effect of a commercial enhancement mode gallium nitride (GaN) high electron nobility transistor (HEMT) with p-type gate structure and cascode structure are studied by using the radiation of heavy ions and &lt;sup&gt;60&lt;/sup&gt;Co gamma in this paper. The safe operating areas ofSEE, the sensitive parameters degradation of TID effect and the SEE and TID characteristics of GaN HEMT device are respectively presented. The experimental results show that the SEE and TID effect have less influence on the p-type gate GaN device. The linear energy transfer (LET) threshold of the single event Burnout effect (SEB) is higher than 37 MeV·cm&lt;sup&gt;2&lt;/sup&gt;/mg and the failure threshold of TID effect is above 1M rad (Si) for p-type gate GaN device. However, the GaN HEMT device with cascode structure is much more sensitive to SEE and TID effect than p-type gate GaN device. Under heavy ions at LET of 22 MeV·cm&lt;sup&gt;2&lt;/sup&gt;/mg and a cumulative dose of 200 krad (Si), the SEB phenomenon and parameters-degradation of cascode-type GaN HEMT are respectively observed. Besides, the circuit structure of the cascode-type GaN HEMT device is analyzed by using metallographic microscope imaging and focused ions beam technology. It reveals the possible reason why it is sensitive to SEB and TID for cascode-type GaN HEMT. These results show that the extra carriers caused by heavy ion radiation can tunnel the Schottky barrier formed by gate metal and AlGaN layer, leading to a large source-drain current in GaN HEMT device. Meanwhile, it is shown that the metal oxide semiconductor field-effect transistor in cascode circuit for TP90H180PS GaN HEMT may be the main reason why the cascode-type GaN HEMT is sensitive to TID.

Radiation-Induced Degradation Analysis and Reliability Modeling of COTS ADCs for Space-Borne Miniature Fiber-Optic Gyroscopes

Respecting the requirements of lightweight, small size, low power consumption and especially low cost, commercial off-the-shelf (COTS) analog-to-digital converters (ADCs) are gradually being used to replace specifically designed aerospace -grade ones in space-borne miniature interferometric fiber-optic gyroscopes (IFOGs). However, the total ionizing dose (TID) effect of $\gamma $ -ray radiation in the space environment may cause the damage of COTS ADCs, and lead to performance degradation and even the failure. In order to measure the safety of COTS ADCs in IFOGs under the TID effect, the radiation-induced degradation model and the corresponding reliability model are proposed in this work. First of all, the relationship between the degradation of COTS ADCs and the IFOG’s angular random walk (ARW) is deduced. Then, a radiation accelerated test is designed and performed, with a real-time, dynamic data acquisition method based on the first-input-first-output (FIFO) memories to determine the degradation of COTS ADCs. Finally, a degradation path model is established based on the degradation data, and the reliability of COTS ADCs used for space-borne IFOGs is further obtained by using the Monte Carlo method. An engineering application is introduced to show the effectiveness of the proposed model, and the results show that the reliability of the experimental COTS ADCs makes them usable for the space-borne miniature IFOGs in low-earth orbit (LEO) and geostationary earth orbit (GEO) space missions.

Statistical characteristics of total ionizing dose effects of bipolar transistors

The base current (&lt;i&gt;I&lt;/i&gt;&lt;sub&gt;B&lt;/sub&gt;) of silicon bipolar transistor degrades when it is subjected to total ionizing dose (TID) irradiation, which is due to the generation of oxide trapped charges (&lt;i&gt;N&lt;/i&gt;&lt;sub&gt;ot&lt;/sub&gt;) in the oxide layer and interface traps (&lt;i&gt;N&lt;/i&gt;&lt;sub&gt;it&lt;/sub&gt;) at the silica/silicon interface. In this work, we investigate the statistical characteristic of &lt;i&gt;I&lt;/i&gt;&lt;sub&gt;B&lt;/sub&gt; of bipolar transistors and its possible microscopic origin. Especially, we carry out TID irradiation experiments on a large sample size of gated lateral PNP (GLPNP) transistors. Forty GLPNP transistors are sequentially irradiated to the total doses of 0.6 krad (Si), 2.6 krad (Si), 4.0 krad (Si), 7.4 krad (Si), and 10.8 krad (Si). The statistical characteristics of their &lt;i&gt;I&lt;/i&gt;&lt;sub&gt;B&lt;/sub&gt;&lt;italic/&gt;, &lt;i&gt;N&lt;/i&gt;&lt;sub&gt;ot&lt;/sub&gt;, and &lt;i&gt;N&lt;/i&gt;&lt;sub&gt;it&lt;/sub&gt; are obtained from the Gummel, gate sweep (GS), and sub-threshold sweep (DS) curves, respectively. It is found that no matter what the dose is, &lt;i&gt;I&lt;/i&gt;&lt;sub&gt;B&lt;/sub&gt;&lt;italic/&gt;, &lt;i&gt;N&lt;/i&gt;&lt;sub&gt;ot&lt;/sub&gt;, and &lt;i&gt;N&lt;/i&gt;&lt;sub&gt;it&lt;/sub&gt; all follow a lognormal distribution. However, the distribution parameters change as the irradiation dose increases. Remarkably, the statistical median and standard deviation of &lt;i&gt;I&lt;/i&gt;&lt;sub&gt;B&lt;/sub&gt; as a function of dose show a strong correlation with those of &lt;i&gt;N&lt;/i&gt;&lt;sub&gt;ot&lt;/sub&gt;&lt;italic/&gt;, but essentially differ from those of &lt;i&gt;N&lt;/i&gt;&lt;sub&gt;it&lt;/sub&gt;. This fact uncovers that for our research objects and dose rate, the sample-to-sample variability of &lt;i&gt;I&lt;/i&gt;&lt;sub&gt;B&lt;/sub&gt; mainly stems from the variation of &lt;i&gt;N&lt;/i&gt;&lt;sub&gt;ot&lt;/sub&gt;&lt;italic/&gt;. These interesting results should have potential applications in exploring the mechanism and evaluating the irradiation reliability of bipolar microcircuits.

Mitigating MOSFET Radiation Effects by Using the Wave Layout in Analog ICs Applications

This paper presents an experimental comparative study of the Total Ionizing Dose (TID) effects between the Metal-Oxide-Semiconductor (MOS) Field Effect Transistors (MOSFET) manufactured with the Wave (S gate geometry) and the standard layout (CnM). Because of the special geometric characteristic of the gate, drain and source regions of the Wave MOSFET (WnM), this innovative layout proposal for transistors is able to mitigate the TID effects in order to implement in analog integrated circuits (IC) for space and medical applications without causing any additional cost to the Complementary MOS (CMOS) manufacturing process.

Experimental investigation on total-ionizing-dose radiation effects on the electrical properties of SOI-LIGBT

In this paper, the experimental investigation on the electrical properties of silicon-on-insulator lateral insulated-gate bipolar transistor (SOI-LIGBT) after total-ionizing-dose (TID) irradiation is presented. We find that the TID irradiation reduces the threshold voltage (Vth), and increases the collector current (ICE) at the same gate voltage (Vg). The raising ICE is mainly attributed to the negative shift of the Vth. However, at the same overdrive voltage (Vov = Vg − Vth), the ICE at small VCE increases and the ICE at high VCE decreases after irradiation. The distinctive response of the out-put characteristics after irradiation is ascribed to the positive trapped charges in the field oxide (FOX) layer and the buried oxide (BOX) layer. The inimitable out-put behavior occurs at whatever the sign of the gate bias voltage during irradiation. The degradation mechanisms of the TID effects on the SOI-LIGBT are further analyzed and confirmed by simulation.

Total ionizing dose effects on digital micromirror devices

There is interest in deploying digital micromirror devices (DMDs) in space for use in multi-object spectrometers, but the devices must first be qualified for space deployment. An environmental test campaign has been carried out on eXtended Graphics Array (XGA) DMDs to qualify the devices for space deployment. The campaign has included mechanical shock and vibration, low temperature, proton radiation, and heavy ion radiation testing. XGA DMDs have passed each test at a level suitable for space deployment. Our paper reports on gamma radiation testing of XGA DMDs, the final portion of the environmental test campaign. Gamma radiation causes total ionizing dose (TID). A total of 19 DMDs were irradiated to TIDs between 16 and 45 krad(Si) while biased and 24 and 76 krad(Si) while unbiased. The effects of TID on DMDs are similar to other electrostatically operated micro-electrical mechanical systems, and all irradiated DMDs were fully recovered by annealing. In addition to testing, radiation modeling of the space environment was performed to determine the expected TID for various space mission scenarios. DMDs have minimal susceptibility to TID effects, and the effects do not significantly compromise the use of the devices for space missions in orbit at L2 or low Earth orbit.