Total Dose Radiation Effects Research Articles

Effects of Total Dose Radiation on Single Event Effect of the Uniaxial Strained Si Nano NMOSFET

The effect of total dose radiation on the single event effect of uniaxial strained Si Nano channel metal oxide semiconductor field effect transistor (NMOSFET) was studied by TCAD simulation. By comparing the experimental results, the TCAD simulation model of the 50 nm strained Si NMOS device is established. The model is used to simulate the off-state single event effect (V ds = 0.05) of NMOSFET under the total dose radiation. The results show that total dose radiation increases the body potential of NMOSFET devices and intensifies the single event transient process of NMOSFET devices. The transient current increases by 4.88% and the drain charge increases by 29.15% under the total dose of 2KGy, which indicates that the effect of total dose radiation on the single event effect is the main factor affecting the collection of drain charge. Therefore, the experimental results and the established model provide good reference for the study of irradiation reliability of the uniaxial strained Si Nano NMOSFET and the application of strained integrated circuits.

Study and Analysis of Enclosed Gate FET’s

The characteristic and parametric dimensioning of Enclosed Layout (ELT) MOSFET with various geometric sizes and shapes has been taken into consideration for the study of irradiations and leakage at room temperature, which has been confirmed on several technological platforms. Using the most advanced technologies, parametric changes with minimum W/L ratios, layout area and input capacitance to reduce leakage current can improve the performance. The technique of hardening of the MOSFETs in contrary to total-dose radiation effects in space environment built in enclosure to the enclosed transistor for the elimination of edges, responsible of conventional NMOS transistors leakage path creation. High yielding, high level of integration, radiation immune, high speed, low costing and high volume production are the profit advantages of the enclosed layout.

A Comparative Study of the γ‐Ray Radiation Effect on Zr‐Doped and Al‐Doped HfO2‐Based Ferroelectric Memory

The γ‐ray total dose radiation effects on Zr‐doped HfO2 (HfZrO) and Al‐doped HfO2 (HfAlO) ferroelectric thin films are comparatively studied. The J–E, P–E, C–V, εr–f curves and fatigue characteristics of both HfZrO and HfAlO thin films are measured and analyzed with the increasing total dose from 0 to 5 Mrad (Si). The remnant polarization (Pr) values of both HfZrO and HfAlO thin films first decrease and then increase with the increasing total dose. A competitive mechanism between the pinned domains and increasing polarization switching charges induced by radiation is proposed to explain this phenomenon. This work presents doped HfO2 film with great radiation tolerance for nuclear and aerospace applications.

Impact of the radiation effect on the energy storage density and wake-up behaviors of antiferroelectric-like Al-doped HfO2 thin films.

The effect of the γ-ray total dose radiation on the energy storage density (ESD) and the phase transition of antiferroelectric-like (AFE-like) Al-doped HfO2 (HfAlO) thin films was investigated. The ESD property and wake-up behavior of the phase transition during the field cycling of the AFE-like HfAlO thin films were quantified before and after the radiation. The efficiency of the AFE-like thin films for energy storage slightly decreases as the total dose increases from 200 krad (Si) to 5 Mrad (Si), which is attributed to the radiation-induced trapped defects at the interfaces of HfAlO/TiN. Both the J-E, C-V, and εr-f characteristics of the AFE-like HfAlO thin films were also measured before and after the radiation at the same electrodes. These results further confirm that the ferroelectricity of the thin films can be reduced due to the radiation oxide trapped defects. It is worth noting that an enhanced wake-up behavior of the AFE-like HfAlO thin films can be observed after the radiation, which indicates that the transition from the antiferroelectric phase to the ferroelectric phase could be accelerated by the increased radiation-induced defects.

Impact of Radiation Effect on Ferroelectric Al-Doped HfO2 Metal-Ferroelectric- Insulator-Semiconductor Structure

The $\gamma $ -ray total dose radiation effects on ferroelectric Al-doped HfO2 (HfAlO) thin films with an n-type Si substrate were studied. The $I$ - $V$ , $P$ - $V$ , $C$ - $V$ and fatigue characteristics of the HfAlO-based Metal-Ferroelectric-Insulator-Semiconductor (MFIS) structure were analyzed with the increasing total dose from 0 to 1 Mrad (Si). The remnant polarization ( $P_{\mathrm {r}}$ ) values, the capacitance ( $C$ ) values and the switching voltage ( $V_{\mathrm {c}}$ ) of this MFIS gate structure decreased with the increasing total dose. A TCAD model of Metal/HfAlO/SiO2/Si (MFIS) was proposed to explain the degradation mechanism of ferroelectric properties of the MFIS structure. We find that the new interface defects caused by radiation can reduce the electric field strength with the increasing total dose, which can significantly influence the irradiation properties of the HfAlO/SiO2/n-Si gate structure. These results provide the basis to applications for the HfO2-based devices in radiation working environment.

Threshold Voltage Model of Total Ionizing Irradiated Short-Channel FD-SOI MOSFETs With Gaussian Doping Profile

This paper investigates the effect of total dose radiation on the electrostatic potential distribution and the related short-channel effects (SCEs) of silicon-on-insulator (SOI) metal-oxide-semiconductor (MOS) devices with a vertical Gaussian doping profile. A new approximation of the 2-D potential function perpendicular to the channel for fully depleted SOI MOS field-effect transistors (FETs) is applied in the analytical threshold voltage model derivation. The impact of interface traps and oxide-trapped charge on the electrostatic potential profile, scaling, and SCEs are verified with TCAD simulations. The model agrees well with the experimental extractions of SCE in n-channel MOSFETs.

FAINTSTAR: an intelligent single-chip sensor head for star trackers—prototype results

Since 2003 the European Space Agency’s roadmap for star tracker CMOS APS (active pixel) image sensors has included developments to integrate significant logic functionality with the pixel array, aiming at an imaging system-on-chip. FaintStar (FS) will be the first commercially available product resulting from these activities. FaintStar is being developed by ams Sensors Belgium (formerly CMOSIS) in two phases. Phase 1 served to specify, design, manufacture, and characterise a prototype chip, informally named FaintStar1 (FS1), the subject of this paper. FaintStar is a one megapixel image sensor with 10 µm pixels and rolling shutter. All interactions with the user are over a single 80 Mb/s SpaceWire link. FaintStar offers various readout modes (full frame, windowed, windowed with dual rolling shutter, etc.). The chip has ‘pixels-to-centroids’ processing, including transfer curve linearisation, bad pixel replacement, background image estimation and suppression, spike filtering, bright object extraction, and photometric barycentre calculation. The algorithms used are generic, i.e., non-reliant on third-party IP, yet highly user-configurable. Data-compressed or raw image output is also supported. The device has been developed for star trackers mainly, although applications such as high-accuracy sun sensing, and navigation, rendezvous, or rover cameras are also served. The prototype chip exceeds its expectations. This article starts with an overview of the FS1 design and reports on the Phase 1 characterisation results, including electro-optical performance, proton displacement damage, total dose, and single event radiation effects. Started end of 2017, the project’s Phase 2 entails minor design refinements, creating FaintStar2 (FS2), its manufacturing, and then a formal evaluation campaign. After this, the sensor will be offered as a commercial off-the-shelf product.

不同偏置状态下4T-CMOS图像传感器的总剂量辐射效应

不同偏置状态下4T-CMOS图像传感器的总剂量辐射效应

Influence of γ-ray total dose radiation effect on the hot carrier gate current of the uniaxial strained Si nano-scale NMOSFET

The carrier microscopic transport process of uniaxial strained Si n-channel metal-oxide-semiconductor field-effect transistor (NMOSFET) has been analyzed under γ-ray radiation. The variation of oxide-trapped charge (Not) and interface-trap charge (Nit) with the total dose has also been investigated. An analytical model of hot carrier gate current of the uniaxial strained Si nanometer scale NMOSFET has been developed with the degradation due to the total dose irradiation taken into consideration. Based on the model, numerical simulation has been carried out by Matlab. The influence of the total dose, geometry and physics parameters on gate current was simulated. Furthermore, to evaluate the validity of the model, the simulation results were compared with experimental data, and good agreements were confirmed. Thus, the proposed model provides good reference for research on irradiation reliability and application of strained integrated circuit of uniaxial strained Si nanometer scale n-channel metal-oxide-semiconductor field-effect transistor.

Study on the influence of γ-ray total dose radiation effect on the electrical properties of the uniaxial strained Si nanometer NMOSFET

The carrier microscopic transport process of uniaxial strained Si n-channel metal-oxide semiconductor field-effect transistor (NMOSFET) has been analyzed under γ-ray radiation. The variation of electrical characteristics of the uniaxial strained Si nanometer NMOSFET has also been investigated under the total dose radiation. The Capacitor-Voltage (C-V) and Current-Voltage (I-V) characteristics are measured at room temperature before and after irradiation for each sample. The results indicate that the drift of threshold voltage, the degradation of carrier mobility and the increase in leakage current because of the total dose radiation effect. Moreover, a two-dimensional analytical model of threshold voltage (Vth) and carrier mobility model have been developed due to the total dose irradiation taken into consideration. Based on the model, numerical simulation has been carried out by MATLAB. The influence of the total dose, geometry and physics parameters on threshold voltage was simulated. Moreover, to evaluate the validity of the model, the simulation results were compared with experimental data, and good agreements were confirmed. Thus, the experiment results and proposed model provide good reference for research on irradiation reliability and application of strained integrated circuit of uniaxial strained Si nanometer n-channel metal-oxide semiconductor field-effect transistor.

Influence of -ray total dose radiation effect on the tunneling gate current of the uniaxial strained Si nanometer n-channel metal-oxide-semiconductor field-effect transistor

The carrier microscopic transport process of uniaxial strained Si n-channel metal-oxide-semiconductor field-effect transistor (NMOSFET) is analyzed under -ray radiation. The model of radiation-induced defect densities that are quantitative representations of trapped charges integrated across the thickness of the oxide (Not), and the number of interface traps at the semiconductor/oxide interface (Nit), is established. The variations of electrical characteristics of the uniaxial strained Si nanometer NMOSFET are also investigated under the total dose radiation. The device of uniaxial strained Si nanometer NMOSTET is irradiated by a 60Co -ray laboratory source at a constant dose rate of 0.5 Gy (Si)/s. The TID is deposited in several steps up to a maximum value of 2.5 kGy. Electrical measurements are performed at each TID step. All irradiated samples are measured using field test, and are required to finish measurement within 30 min, in order to reduce the annealing effect. Static drain-current ID vs. gate-voltage VGS electrical characteristics are measured with an HP4155B parametric analyzer. Some parameter extractions presented here come from these static measurements including the threshold voltage VTH, the trans-conductance gm, and the leakage current IOFF (ID at VGS=0 V and VDS=VDD). Irradiation bias:VG=+1 V, drain voltage VD is equal to source voltage VS (VD=VS=0). Measurement bias:VG=0-1 V, scanning voltage Vstep=0.05 V, VD=50 mV, and VS=0. The results indicate the drift of threshold voltage, the degradation of carrier mobility and the increase of leakage current because of the total dose radiation. Based on quantum mechanics, an analytical model of tunneling gate current of the uniaxial strained Si nanometer is developed due to the total dose irradiation effect. Based on this model, numerical simulation is carried out by Matlab. The influences of total dose, geometry and physics parameters on tunneling gate current are simulated. The simulation results show that when radiation dose and bias are constant, the tunneling gate current increases as the channel length decreases. When the structure parameters and the stress are fixed, the tunneling gate current increases with the increase of radiation dose. Whereas at a given the radiation dose, tunneling gate current will decrease due to the stress. When radiation dose and bias are kept unchanged, the tunneling gate current increases with the thickness of the gate oxide layer decresing. When the gate-source voltage, the thickness of oxide layer and stress are fixed, tunneling gate current is reduced with the increase of doping concentration in channel. When the structural parameters, the gate-source voltage and radiation dose are constant, the tunneling gate current decreases with increasing drain-source voltage. In addition, to evaluate the validity of the model, the simulation results are compared with experimental data, and good agreement is confirmed. Thus, the experimental results and proposed model provide good reference for research on irradiation reliability and application of strained integrated circuit of uniaxial strained Si nanometer n-channel metal-oxide-semiconductor field-effect transistor.

Total dose radiation and annealing responses of the back transistor of Silicon-On-Insulator pMOSFETs**Supported by National Natural Science Foundation of China (61404169)

The total dose radiation and annealing responses of the back transistor of Silicon-On-Insulator (SOI) pMOSFETs have been studied by comparing them with those of the back transistor of SOI nMOSFETs fabricated on the same wafer. The transistors were irradiated by 60Co γ-rays with various doses and the front transistors were biased in a Float-State and Off-State, respectively, during irradiation. The total dose radiation responses of the back transistors were characterized by their threshold voltage shifts. The results show that the total dose radiation response of the back transistor of SOI pMOSFETs, similar to that of SOI nMOSFETs, depends greatly on their bias conditions during irradiation. However, with the Float-State bias rather than the Off-State bias, the back transistors of SOI pMOSFETs reveal a much higher sensitivity to total dose radiation, which is contrary to the behavior of SOI nMOSFETs. In addition, it is also found that the total dose radiation effect of the back transistor of SOI pMOSFETs irradiated with Off-State bias, as well as that of the SOI nMOSFETs, increases as the channel length decreases. The annealing response of the back transistors after irradiation at room temperature without bias, as characterized by their threshold voltage shifts, indicates that there is a relatively complex annealing mechanism associated with channel length, type, and bias condition during irradiation. In particular, for all of the transistors irradiated with Off-State bias, their back transistors show an abnormal annealing effect during early annealing. All of these results have been discussed and analyzed in detail by the aid of simulation.

Application of Pelletron Accelerator to Study High Total Dose Radiation Effects on Semiconductor Devices

Silicon bipolar junction transistors (BJTs), Silicon-germanium heterojunction bipolar transistors (SiGe HBTs) and metal oxide semiconductor (MOS) devices are the key components of BiCMOS integrated circuits. The semiconductor devices need to withstand very high total doses (100’s of Mrad) for reliable operation of electronic circuits for 8-10 years of LHC operation. The study of radiation tolerance of semiconductor devices up to 100 Mrad of total dose takes longer time with conventional60Co gamma, proton and electron irradiation facilities and the effects due to these radiations are well understood. Hence it is important to study the effects of heavy ion irradiation on various semiconductor devices. The irradiation time decreases with increasing linear energy transfer (LET) of incident radiation and LET increases with atomic number of the impinging ions. But it is essential to understand the mechanism of energy transfer by different heavy ions in semiconductor devices. Therefore, here we give an overview of different heavy ion interactions with Si BJTs, MOSFETs and SiGe HBTs by primarily focusing on the electrical characteristics of these devices before and after ion irradiation. We show that the irradiation time needed to reach very high total dose can be reduced by using Pelletron accelerator facilities instead of conventional irradiation facilities.

Total dose radiation effects of hybrid bulk/SOI CMOS active pixel with buried channel SOI source follower

A CMOS active pixel with pinned photodiode which used in-pixel buried-channel (BC) transistor has been reported, and the characteristic of CMOS image sensor with in-pixel buried-channel transistor was carried out. In this paper, we have a research on a hybrid bulk/silicon-on-insulator (SOI) CMOS active pixel with pinned photodiode which use buried channel SOI NMOS Source Flower (SF) by simulation. We study the basic characteristics of buried-channel SOI NMOS and the characteristics of CMOS active pixel optimized by using in-pixel buried-channel SOI transistor under radiation. The results show that, compared to the conventional active pixel with the standard surface-channel (SC) SOI NMOS SF, the dark random noise of the pixel which uses in-pixel buried channel SOI NMOS SF can be reduced under the radiation and the output swing is improved.

Degradation of saturation output of the COTS array charge-coupled devices induced by total dose radiation damage

Experiments of total dose radiation effects on COTS array charge-coupled device (CCD) and annealing measurements are shown. Degradations of saturation output voltage at different bias conditions are analyzed, and their mechanisms induced by radiation are also demonstrated. Degradations of saturation output imaging at different total doses and the recovery after annealing are also compared. The phenomena of imaging degradation induced by total dose irradiation are analyzed. The camera imaging quality of resolution test card degraded by total dose irradiation is also analyzed. Finally, integration research from the irradiation-sensitive parameter degradation to the camera imaging degradation of the array CCD is achieved.

Study on the influence of γ -ray total dose radiation effect on the threshold voltage and transconductance of the strained Si p-channel metal-oxide-semiconductor field-effect transistor

In this work, the carrier microscopic transport process of biaxial strained Si p-channel metal-oxide-semiconductor field-effect transistor (PMOSFET) under γ -ray radiation has been studied. Effect of γ-ray on devices and the relationship between the variation of device electrical characteristics and the total dose are investigated. A model for considering the degradation of threshold voltage and transconductance due to the total dose radiation is established. Based on this model, numerical simulation has been carried out. Results show that the threshold voltage of PMOSFET decreases with increasing radiation dose. At a lower total dose, the threshold voltage decreases linearly. However, at a higher total dose, it becomes saturated. The degradation can be explained by the generation of trapped charges which increase the impact possibility of carriers in the channel and induce the reduction of mobility and transconductance accordingly. Finally, the simulation results are compared with the experimental data. A good agreement is observed, indicating the validation of our proposed model.

Online and offline test method of total dose radiation damage on static random access memory

In this paper, for the study of static random access memory (SRAM), the online-test and offline-test are carried out on the total dose radiation damages. The differences between the two kinds of test methods and physical mechanisms are investigated. The results show that SRAM present multiple failure mode, the online-test only includes one fixed failure mode and the offline-test includes multiple failure mode. Due to the restrictions on signal integrity at test frequency, the online dynamic current test value is significantly less than offline test value. Since the existence of imprinting effect, the online-test static current is significantly less than offline-test value when the device-stored data are opposite to irradiation data. The parameters that cannot be detected online, may lapse prior to the data that could be detected online. The results are significantly important for studying the total dose radiation effect and the experimental evaluation of SRAM under radiation environment.

Application of a Pelletron accelerator to study total dose radiation effects on 50 GHz SiGe HBTs

We have investigated the effects of 50 MeV lithium ion irradiation on the DC electrical characteristics of first-generation silicon–germanium heterojunction bipolar transistors (50 GHz SiGe HBTs) in the dose range of 600 krad to 100 Mrad. The results of 50 MeV Li 3+ ion irradiation on the SiGe HBTs are compared with 63 MeV proton and Co-60 gamma irradiation results in the same dose range in order to understand the damage induced by different LET species. The radiation response of emitter–base (EB) spacer oxide and shallow trench isolation (STI) oxide to different irradiation types are discussed in this paper. We have also focused on the efficacy in the application of a Pelletron accelerator to study total dose irradiation studies in SiGe HBTs.

A Comparison of Avalanche Injection of Holes and Total Dose Radiation Effects in RadFETs

Radiation sensitive Field Effected Transistors (RadFETs) have been widely used as dosimeters to detect the Total Dose Radiation Effects (TDRE). Because ionizing radiation for testing RadFET samples is costly and inconvenient, Avalanche Injection of Holes (AIH) was introduced to simulate or substitute the radiation methods to evaluate the quality of RadFETs in this paper. Several kinds of dielectric layers of RadFETs were fabricated and the comparison of AIH and TDRE was investigated. It was found that AIH can cause the similar △VTH and annealing change trends with TDRE to predict the radiation characteristics of RadFETs.

Total dose radiation effects on SOI NMOS transistors with different layouts

Partially-depleted Silicon-On-Insulator Negative Channel Metal Oxide Semiconductor (SOI NMOS) transistors with different layouts are fabricated on radiation hard Separation by IMplanted OXygen (SIMOX) substrate and tested using 10 keV X-ray radiation sources. The radiation performance is characterized by transistor threshold voltage shift and transistor leakage currents as a function of the total dose up to 2.0×106 rad(Si). The results show that the total dose radiation effects on NMOS devices are very sensitive to their layout structures.