Heavy Test Research Articles

Design and Testing of a Pulsed Laser System for Single Event Effects Analysis on Semiconductor Devices

Single event upsets (SEUs) are a critical concern for reliability in semiconductor devices, particularly as technology nodes shrink and devices become more susceptible to cosmic rays and other radiation sources. Understanding and mitigating these effects are crucial for ensuring the reliability of electronic systems. By leveraging pulsed laser charge injection, researchers can achieve results comparable to traditional methods like heavy ion testing but at a lower cost and with better control over spatial and temporal parameters. The photogeneration effect in semiconductor devices due to single photon absorption and two-photon absorption is introduced and the test system designed to make use of both type of charge photogeneration is implemented. The design and development of the pulsed laser system at the Saskatchewan Structural Sciences Centre is described. The system's capabilities, such as precise control over pulse parameters and spatial targeting, make it a valuable tool for Single Event Effect (SEE) analysis. The testing of a Static Random Access Memory (SRAM) using this newly developed system provides valuable insights into the device's behavior under radiation-induced faults. By quantifying overall error rates, including multiple-bit errors and faults in memory and control circuitry, researchers can assess the device's susceptibility to SEUs. Comparing the pulsed laser results of SRAM testing with those obtained from heavy ion testing demonstrates the effectiveness of the pulsed laser system. Overall, the new and unique Pulsed Laser System at the SSSC represents a significant advancement in SEE testing capability. Its ability to provide results comparable to traditional methods while offering greater accessibility and control has the potential to drive further innovation in the field of radiation effects analysis in semiconductor devices.

Cluster-Locating Algorithm Based on Deep Learning for Silicon Pixel Sensors.

The application of silicon pixel sensors provides an excellent signal-to-noise ratio, spatial resolution, and readout speed in particle physics experiments. Therefore, high-performance cluster-locating technology is highly required in CMOS-sensor-based systems to compress the data volume and improve the accuracy and speed of particle detection. Object detection techniques using deep learning technology demonstrate significant potential for achieving high-performance particle cluster location. In this study, we constructed and compared the performance of one-stage detection algorithms with the representative YOLO (You Only Look Once) framework and two-stage detection algorithms with an RCNN (region-based convolutional neural network). In addition, we also compared transformer-based backbones and CNN-based backbones. The dataset was obtained from a heavy-ion test on a Topmetal-M silicon pixel sensor at HIRFL. Heavy-ion tests were performed on the Topmetal-M silicon pixel sensor to establish the dataset for training and validation. In general, we achieved state-of-the-art results: 68.0% AP (average precision) at a speed of 10.04 FPS (Frames Per Second) on Tesla V100. In addition, the detection efficiency is on the same level as that of the traditional Selective Search approach, but the speed is higher.

Monte Carlo Tools for Assessing See Data Quality for Different Types of Analyses

After 43 years of Single-Event Effects (SEE) heavy-ion testing, there exists a large body of archival SEE results, almost all of which are intended for estimating on-orbit SEE rates. However, SEE data vary dramatically over a broad range of data-quality metrics. While variable SEE data quality may not be a major source of errors for SEE rates, other uses of the data—e.g., parametric estimation—are less forgiving of low-quality data. We apply a Monte Carlo (MC) tool using a simplified Generalized Linear Model (GLM) SEE data-fitting routine to assess how data quality affects SEE rate bounding, estimation and determination of fit parameters for SEE cross section (σ) vs. LET. The MC tool can generate 1000 MC events in about 1 minute on a standard laptop, making it suitable for on-the-fly testing decisions as well as evaluation of data quality.

Characterization of Single-Event Upsets Induced by High-LET Heavy Ions in 16-nm Bulk FinFET SRAMs

For advanced technology nodes, the static random-access memories (SRAMs) are highly vulnerable to the single-event upsets (SEUs), especially the multiple cell upsets (MCUs), by a high energy ion strike, which is due to the small transistor size and close proximity of the sensitive regions. However, the narrow connection between the fin and the bulk region for FinFET inhibits the charge collection compared to the planar transistor structure. In this work, heavy ion tests were conducted for 16 nm bulk FinFET dual-port SRAM at two high linear energy transfers (LETs) of 60 MeV∙cm2/mg and 85 MeV∙cm2/mg. The non-saturating behavior of the SEU cross-sections and event cross-sections for a bit cell is observed even over the LET of 60 MeV∙cm2/mg due to the expanding of the sensitive area surrounding the array and the cutting-off area in the FinFET SRAM cells. The distribution curves of the MCU event probabilities for different MCU cluster sizes show the Single-bit upset (SBU) occupies the largest probability of all the single-event cluster sizes, which exhibits the inhibition capability of the Fin structure against the upsets induced by high energy particles. The parasitic bipolar effect is also serious for 16nm FinFET SRAM as former planar SRAM, but the charge sharing effect is effectively inhibited due to the narrow connection between the fin and the bulk region for FinFET. Results presented in this paper will help designers estimate the Error Correcting Code (ECC) and interleaving design parameters for radiation hardened SRAM designs at the 16 nm FinFET process.

Pulsed-Laser Testing to Quantitatively Evaluate Latchup Sensitivity in Mixed-Signal ASICs

Pulsed-laser testing is used to accurately determine single-event latchup (SEL) thresholds for static random-access memories (SRAMs) with different body-tie-to-drain spacings on a mixed-signal application-specific integrated circuit (ASIC), a study that could not be completed using only broad-beam heavy-ion testing. Two distinct approaches were employed with the first approach, an empirical correlation method, exploiting the complementary nature of broad-beam heavy-ion and laser testing. Various single- and dual-port SRAMs exhibited SEL thresholds ranging from 1 MeV-cm²/mg to over 100 MeV-cm²/mg, with a dual-port device possessing the smallest body-tie-to-drain spacing being latchup immune at the highest available test conditions (>300 MeV-cm²/mg). These results have been used to inform a follow-on ASIC design resulting in a significant improvement in chip-level SEL sensitivity. The second approach, a calculational method, uses pulsed-laser measurements and charge-deposition modeling to predict linear energy transfer (LET) thresholds without heavy-ion data. This calculational approach agrees with the empirical approach and therefore shows promise as a predictive tool for SEL threshold estimation, but further validation is required. Overall, these approaches can be effective tools for evaluating SEL susceptibilities and mitigation strategies.

Heavy-Ion Testing Method and Results of Normally OFF GaN-Based High-Electron-Mobility Transistor

Gallium nitride (GaN) power switches are promising devices for power conversion applications because this new technology enables the design of power converters with higher efficiency and reduced size than those achievable with conventional silicon devices. For space applications, normally-OFF devices are mandatory to avoid potential current shoot through during startup or loss of power control. The use of these devices in space environment shall be carefully considered with respect to natural radiation and especially under heavy-ion impact that can induce the burnout of the device known as single-event effect (SEE) failure. Therefore, radiation hardness evaluation of GaN devices is of prime interest. Another important parameter affecting GaN power device reliability is the current collapse or dynamic <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$R_{\mathrm{\scriptscriptstyle ON}}$ </tex-math></inline-formula> since in particular functioning condition, the device can generate extra losses that may lead to failure. Five commercial off-the-shelf (COTS) GaN high-electron-mobility transistor (HEMT) references were selected and tested under heavy ions. This article presents first the testing methodology and device preparation used for heavy-ion test campaign. Then observations from the irradiation run are presented and discussed. At last, a potential dynamic <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$R_{\mathrm{\scriptscriptstyle ON}}$ </tex-math></inline-formula> issue with respect to heavy-ion safe operating area (SOA) of one reference is highlighted.

Simulation of Pulsed-Laser-Induced Testing in Microelectronic Devices

A method to carry out a priori simulations of pulsed-laser-induced single-event effects experiments is reported. Nonlinear optical simulations are conducted to model the 3-D distributions of charge from a laser pulse. These pulsed-laser-induced charge distributions are then incorporated into a charge transport solver to model the movement of charge as the device returns to a steady state. The output of the simulation infrastructure is a current transient from which collected charge and the temporal characteristics of the transient can be determined. This complete approach to modeling, which includes full device structure information, nonlinear optical energy deposition, and the subsequent movement of optically generated charge in a device and measurement circuit, allows for direct comparison between experimental and simulated current transients. A large-area silicon diode was used as the test vehicle, and good agreement was found between simulations and experiments in both total injected charge as well as temporal characteristics. Importantly, the a priori simulation approach does not require knowledge from prior heavy-ion testing, making it a predictive tool with broad versatility and minimal reliance on approximations.

The Study of the Single Event Effect in AlGaN/GaN HEMT Based on a Cascode Structure

An attractive candidate for space and aeronautic applications is the high-power and miniaturizing electric propulsion technology device, the gallium nitride high electron mobility transistor (GaN HEMT), which is representative of wide bandgap power electronic devices. The cascode AlGaN/GaN HEMT is a common structure typically composed of a high-voltage depletion-mode AlGaN/GaN HEMT and low-voltage enhancement-mode silicon (Si) MOSFET connected by a cascode structure to realize its enhancement mode. It is well known that low-voltage Si MOSFET is insensitive to single event burnout (SEB). Therefore, this paper mainly focuses on the single event effects of the cascode AlGaN/GaN HEMT using technical computer-aided design (TCAD) simulation and heavy-ion experiments. The influences of heavy-ion energy, track length, and track position on the single event effects for the depletion-mode AlGaN/GaN HEMT were studied using TCAD simulation. The results showed that a leakage channel between the gate electrode and drain electrode in depletion-mode AlGaN/GaN HEMT was formed after heavy-ion striking. The enhancement of the ionization mechanism at the edge of the gate might be an important factor for the leakage channel. To further study the SEB effect in AlGaN/GaN HEMT, the heavy-ion test of a cascode AlGaN/GaN HEMT was carried out. SEB was observed in the heavy-ion irradiation experiment and the leakage channel was found between the gate and drain region in the depletion-mode AlGaN/GaN HEMT. The heavy-ion irradiation experimental results proved reasonable for the SEB simulation for AlGaN/GaN HEMT with a cascode structure.

Simultaneous Single-Event Transient (SET) Observation on LM139A Wired-and Comparator Circuit

The sensitivity of the LM139A quad voltage comparator toward simultaneous single-event transient has been investigated through laser single photon absorption. The results have been supported and compared to heavy-ion tests. The analysis of sensitivity leads to the observation of two sensitive cases related to internal charge-sharing mechanism between comparator function and input line coupling effects.

Evaluation Method of Heavy-Ion-Induced Single-Event Upset in 3D-Stacked SRAMs

The interaction of radiation with three-dimensional (3D) electronic devices can be determined through the detection of single-event effects (SEU). In this study, we propose a method for the evaluation of SEUs in 3D static random-access memories (SRAMs) induced by heavy-ion irradiation. The cross-sections (CSs) of different tiers, as a function of the linear energy transfer (LET) under high, medium, and low energy heavy-ion irradiation, were obtained through Monte Carlo simulations. The simulation results revealed that the maximum value of the CS was obtained under the medium-energy heavy-ion penetration, and the effect of penetration range of heavy ions was observed in different tiers of 3D-stacked devices. The underlying physical mechanisms of charge collection under different heavy-ion energies were discussed. Thereafter, we proposed an equation of the critical heavy-ion range that can be used to obtain the worst CS curve was proposed. Considering both the LET spectra and flux of galactic cosmic ray (GCR) and the variation in the heavy-ion Bragg peak values with the atomic number, we proposed a heavy-ion irradiation test guidance for 3D-stacked devices. In addition, the effectiveness of this method was verified through simulations of the three-tier vertically stacked SRAM and the ultrahigh-energy heavy-ion irradiation experiment of the two-tier vertically stacked SRAM. this study provides a theoretical framework for the detection of SEUs induced by heavy-ion irradiation in 3D-integrated devices.

SE Response of Guard-Gate FF in 16- and 7-nm Bulk FinFET Technologies

Single-event (SE) performance of the guard-gate flip-flop (GG-FF) and conventional D-FF designs is evaluated at the 16- and 7-nm FinFET technology nodes. The heavy-ion test results show that at the 16-nm node, the GG-FF shows better SE performance for low-linear energy transfer (LET) particles and similar performance for high-LET particles compared with D-FF design. However, at the 7-nm node, the GG-FF shows better SE performance than the D-FF across a wide range of particle LET values. This behavior is due to the higher number of short SE transient (SET) pulses for high-LET particles at the 7-nm node. The heavy-ion test results are used to estimate the number of short SET pulses as a function of particle LET values.

Design of a High-Performance Low-Cost Radiation-Hardened Phase-Locked Loop for Space Application

In the harsh space environment, the phase-locked loop (PLL) circuit is vulnerable to radiation effects, which will lead to performance degradation or even function interrupts. In this article, a rad-hard low-noise PLL is designed with low power and area overhead and verified in a 130-nm silicon-on-insulator process. Heavy ion test demonstrates that the proposed PLL is immune to the single-event effect up to 83.7 MeV·cm2/mg. Furthermore, its single-event sensitivity is characterized and compared with an unhardened PLL by the pulsed laser test. Finally, the gamma-ray radiation experiment confirms that it can provide >300 krad(Si) total ionizing dose assurance.

A Methodology for Reconstructing DSET Pulses from Heavy-Ion Broad-Beam Measurements

A table-based method for the estimation of heavy-ion-induced Digital Single Event Transient (DSET) voltage pulse-width in a single logic cell has been developed. The estimation method is based on the actual heavy-ion-induced transient current data in a single metal-oxide-semiconductor field effect transistor (MOSFET) used in the logic cell. The DSET pulse waveform in an inverter is obtained from which the pulse-width was estimated to be 420 ps. This DSET pulse-width value (420 ps) falls within the reasonable range of the DSET pulse-width distribution measured by the self-triggering flip-flop latch chain under heavy-ion irradiation test conditions.

Investigation of Buried-Well Potential Perturbation Effects on SEU in SOI DICE-Based Flip-Flop Under Proton Irradiation

The effects of buried-well potential perturbation under the buried-oxide (BOX) layer are studied in both a heavy-ion single event upset (SEU) test and a high-energy proton-SEU test of a silicon-on-insulator (SOI) dual interlocked storage cell (DICE)-based flip-flop. Their dependence on incident angle and back bias is discussed. We fabricated both DICE-based flip-flop and conventional flip-flop, which are designed as 80 000-stage shift-register chains. In a heavy-ion test, a considerable number of SEUs were observed at back bias exceeding 2.4 V, and a ten-times larger SEU-cross section was finally recorded at back bias of 3.0 V compared with the total active area of a DICE-based flip-flop cell. This marks the first case where DICE topology was found to be broken by buried-well potential perturbation on an SOI DICE-based flip-flop. In a proton test, one error was observed at back bias of 2.0 V. The SEU rate in the Van Allen belt at an altitude of 2300 km and an inclination of 90° was estimated as being once every 5 years.

Prediction of proton single event upset sensitivity based on heavy ion test data in nanometer hardened static random access memory

In order to evaluate the radiation tolerance to proton single event effect(SEE) in nanometer dual interlocked cell (DICE) hardening device accurately, single event upset (SEU) linear energy transfer (LET) threshold at heavy ion normal and tilt incidence, and the worst case SEU orientational angle are acquired based on the analysis of heavy ion SEU testing data in 65 nm dual DICE static random access memory (SRAM). It is proved that dual DICE design is effective for improving the LET threshold against SEU. Howerer, heavy ion tilt incidence at the worst orientational angle will significantly reduce the SEU threshold and increase the SEU cross section. The worst orientational angle for SEU in DICE SRAM is the large tilting angle along the well. The maximum LET value and the emission angle distribution of secondary particle induced by the nuclear reaction between protons with different energy and layers with different multiple metallization are obtained by using Monte-Carlo simulation. The maximum LET value of secondary particle from proton-copper spallation reaction is higher than 15 MeV·cm&lt;sup&gt;2&lt;/sup&gt;/mg for 100 MeV and 200 MeV protons. Secondary particles with the maximum energy and longest range are emitted preferentially in the forward direction. Proton SEU sensitivity is further predicted through combining heavy ion test data with Monte-Carlo simulation. Proton SEU test data verify the effectiveness of the prediction method and the accuracy of the prediction results. The research results indicate that the tolerance of nanometer DICE hardening technique against proton SEU will be overestimated if SEE evaluation test is carried out with only 100 MeV proton accelerator or normal incidence. Proton single event upset in nanometer dual DICE SRAM has an evident dependence on tilt angle and orientational angle. By adopting the above prediction method, whether proton SEE test needs performing or not in nanometer radiation-hardening device can be judged and screened. The requirements for the maximum energy of proton accelerator can be ascertained. In order to ensure that the devices are applied to space with high reliability, SEE test should be carried out including tilt incidence at the worst orientational angle in nanometer DICE hardening device in the process of heavy ion and proton SEE test evaluation.

Outstanding Conference Paper Award: 2019 IEEE Nuclear and Space Radiation Effects Conference

In this work, experimental results are presented on single-bit-upsets (SBU) and multiple-bit-upsets (MBU) on a 45 nm SOI SRAM. The upset cross-sections were obtained with accelerated testing using both protons and heavy ions. The proton upset cross-sections were obtained using proton energies ranging from 1 to 500 MeV and the heavy ion data were obtained using ions with effective linear energy transfer (LET) values from 0.6 to 100 . Overall, the SBU data on the 45 nm SOI SRAM showed upset cross-sections-per-bit that were very similar to the cross-sections-per-bit on a 65 nm SOI SRAM for both heavy ion and proton testing. This result continues a trend that has been observed with advanced SOI CMOS SRAMs. In contrast to the SBU data, the MBU data on the 45 nm SRAM showed significantly higher upset cross-sections relative to the 65 nm SRAM. The higher MBU cross-sections were also expected based upon the closer spacing of the nodes in adjacent cells. While the overall trends were anticipated, the major focus of the paper was to understand a diverse range of single event effects that were contributing to the measured upsets. As a function of the incident proton energy, both scattering events and direct ionization upsets were observed. The data also highlighted the unique upset results that are produced at a 90 degree tilt angle. The MBU data showed a very large dependence on the data stored in the SRAM. The data dependence was understood based upon the layout of the SRAM cells and the MBU upsets produced by strikes in common diffusion regions. A detailed analysis of the MBU data showed that almost all of the MBU events occurred in adjacent cells along the bit-lines of the array. This result is very important since the MBU events along the same bit-line will be effectively corrected by error-correctingcode (ECC) circuits. Thus, the higher overall MBU cross-sections that were observed with technology scaling are not a critical issue in SOI SRAMs that use ECC circuits. David F. Heidel received his B.S. degree in physics from Miami University in 1974, and his M.S. and Ph.D. degrees in physics from The Ohio State University in 1976 and 1980 respectively. In 1980, he joined IBM’s Research Division, at the Thomas J. Watson Research Center in Yorktown Heights, NY, working on Josephson superconducting technology. Since

SEE Sensitivity Evaluation for Commercial 16 nm SRAM-FPGA

Radiation effects can induce severe and diverse soft errors in digital circuits and systems. A Xilinx commercial 16 nm FinFET static random-access memory (SRAM)-based field-programmable gate array (FPGA) was selected to evaluate the radiation sensitivity and promote the space application of FinFET ultra large-scale integrated circuits (ULSI). Picosecond pulsed laser and high energy heavy ions were employed for irradiation. Before the tests, SRAM-based configure RAMs (CRAMs) were initialized and configured. The 100% embedded block RAMs (BRAMs) were utilized based on the Vivado implementation of the compiled hardware description language. No hard error was observed in both the laser and heavy-ion test. The thresholds for laser-induced single event upset (SEU) were ~3.5 nJ, and the SEU cross-sections were correlated positively to the laser’s energy. Multi-bit upsets were measured in heavy-ion and high-energy laser irradiation. Moreover, latch-up and functional interrupt phenomena were common, especially in the heavy-ion tests. The single event effect results for the 16 nm FinFET process were significant, and some radiation tolerance strategies were required in a radiation environment.

Using Bessel beams and two-photon absorption to predict radiation effects in microelectronics.

Pulsed-laser testing is an attractive tool for studying space-based radiation effects in microelectronics because it provides a high degree of spatial resolution and is more cost-effective than conventional accelerator-based testing. However, quantitatively predicting the effects of radiation is challenging for this optical method. A new approach to pulsed-laser testing is presented, which addresses these challenges by using a Bessel beam and carrier generation via two-photon absorption. By producing a carrier distribution in the device under test that is similar to that of a heavy ion, this optical approach aims to quantitatively predict the response of the device under heavy ion tests that represent space radiation. Furthermore, the carrier distribution can be accurately described using a single analytic expression thereby enabling the laser to be tuned to emulate a specific heavy ion. Herein, we describe the modifications made to an existing pulsed-laser setup to generate this carrier distribution, characterize this distribution using a novel method that provides sub-micron spatial resolution, and provide the equations that describe the distribution. Finally, we use this method to study a silicon photodiode and find that the transient response of the device shows strong agreement with the response generated using heavy ions.

SEE Tests With Ultra Energetic Xe Ion Beam in the CHARM Facility at CERN

Taking advantage of the heavy ion acceleration program, tests on radiation effects with Ultrahigh Energy (UHE) xenon ion beams (with Energy > 5 GeV/nucleon) have been performed in several experimental areas of the CERN accelerator complex. Specifically, the outcomes of the first UHE heavy ion test campaign carried out at the CHARM facility are presented and discussed in this contribution. UHE ion beams have the advantage of not requiring a previous modification of the samples or testing in vacuum, owing to their large penetration range. The unique nature of the UHE ions motivated the study of their interaction with matter, with regard to the induction of SEE. To that end, great effort was paid on the calibration of the beam line instrumentation, typically prepared for the traditional proton runs. Electronic components sensitive to single event upset (SEU) and single-event latchup (SEL) were irradiated by an UHE xenon beam, with a particular interest in studying the sub-LET cross section region and benchmarking against the standard heavy ion test beams. Finally, the suitability of UHE ion testing for Radiation Hardness Assurance is also discussed in the contribution.

Radiation-Hardened Structure to Reduce Sensitive Range of a Stacked Structure for FDSOI

Flip-flops (FFs) with stacked transistors have high radiation tolerance in a fully depleted silicon on insulator (FDSOI) process. However, the FFs are weak against a radioactive particle hit with high linear energy transfer (LET) and from high incident angles. In this paper, we used heavy-ion irradiation tests to evaluate the soft-error tolerance of a stacked structure and a radiation-hardened structure in an attempt to reduce sensitive range (RSR). We propose a novel FF with the RSR structure. We fabricate a chip in a 65-nm FDSOI process with three latches, each with different distances between stacked transistors. Experimental results reveal that the stacked structures are weak against a heavy-ion hit that exceeds a LET of 60 MeV $\cdot $ cm2/mg even though the distance between stacked transistors was increased from 250 to 350 nm. We evaluated the RSR structure by TCAD simulations and measured the radiation hardness of the proposed FF by heavy-ion irradiation on the fabricated chips. Measurement by heavy ions with LET of 67.2 MeV $\cdot $ cm2/mg at all angles show no detectable errors in the proposed FF.