Characterization of single event effect simulation in InP-based High Electron Mobility Transistors

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 <sup>60</sup>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<sup>2</sup>/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<sup>2</sup>/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.

In this paper, we present simple digital-based pulse generators (PGs) that emit short pulses with a full width at half-maximum (FWHM) of only several picoseconds in order to realize millimeter-wave impulse radio (IR) systems that can transmit signals at 10 Gbps and above. There are distinctive advantages of using digital techniques. Scaling devices and reducing parasitic capacitances can enhance performance, which is examined by a transition analysis of the PGs. Secondly, retiming techniques enable the PGs to suppress jitter, which is essential for maintaining transmission quality. Two types of PGs are demonstrated: Type-I PG with advanced 75 nm InP-based high electron mobility transistors (HEMTs) having a cavity structure generated short pulses with a record FWHM of <4.9 ps at 20 Gbps, realizing sub-THz IR systems. Type-II PG with mature 100 nm InP-based HEMTs without the cavity retimed 6.5 ps pulses, resulting in very small jitter of 256 fs. Type-II PG was used to construct an IR transmitter of over 10 Gbps at millimeter-wave frequencies (75–110 GHz).

The performance damage mechanism of InP-based high electron mobility transistors (HEMTs) after proton irradiation has been investigated comprehensively through induced defects. The effects of the defect type, defect energy level with respect to conduction band ET, and defect concentration on the transfer and output characteristics of the device are discussed based on hydrodynamic model and Shockley–Read–Hall recombination model. The results indicate that only acceptor-like defects have a significant influence on device operation. Meanwhile, as defect energy level ET shifts away from conduction band, the drain current decreases gradually and finally reaches a saturation value with ET above 0.5 eV. This can be attributed to the fact that at sufficient deep level, acceptor-type defects could not be ionized any more. Additionally, the drain current and transconductance degrade more severely with larger acceptor concentration. These changes of the electrical characteristics with proton radiation could be accounted for by the electron density reduction in the channel region from induced acceptor-like defects.

The authors report on the state-of-the-art power performance of InP-based HEMTs (high electron mobility transistors) at 59 GHz. Using a 448- mu m-wide HEMT with a gate length of 0.15 mu m, an output power of 155 mW with a 4.9-dB gain and a power-added efficiency of 30.1% were obtained. By power-combining two of these HEMTs, an output power of 288 mW with 3.6-dB gain and a power-added efficiency of 20.4% were achieved. This is the highest output power reported with such a high efficiency for InP-based HEMTs, and is comparable to the best results reported for AlGaAs/InGaAs on GaAs pseudomorphic HEMTs at this frequency. >

This article presents novel radiation hardening design techniques to substantially reduce the single-event effects (SEEs) on high-frequency receivers subject to various radiations when operating in space. A <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$W$ </tex-math></inline-formula> -band (75–110 GHz) receiver front-end implemented in Global Foundry’s 90-nm silicon–germanium (SiGe) BiCMOS technology is used for studying SEE and investigating the effectiveness of the proposed techniques. Specifically, the mixer is modified to allow for different modes of operation in addition to introducing matching considerations between the mixer’s gain and switching stages. The receiver includes integrated high-frequency signal sources to provide the input radio frequency (RF) and local oscillator (LO) signals for full operation of the proposed millimeter-wave (mmW) receiver. Measurements are taken while the receiver is in normal operation (RF and LO are applied). The design techniques are carefully analyzed via extensive simulations using equivalent transient current pulses obtained from calibrated technology computer-aided design (TCAD) simulations. A two-photon absorption (TPA) pulsed laser experiment is used to induce transient currents in the silicon–germanium heterojunction bipolar transistor (SiGe HBT) circuit. Various devices within the mixer are hit from the back side through a hole in the designed printed circuit board (PCB). The propagated transients are then captured using a high-speed oscilloscope at the output of the receiver. The measurement results, supported by simulations and analysis, validate the robustness of the proposed radiation hardened receiver to SEE.

We propose a physics-based analytical model that accurately captures the effects of buffer traps on dc characteristics of gallium nitride (GaN)-based high-electron-mobility transistors (HEMTs). The model is then semi-analytically extended to additionally include the transient behavior. Analytical formulations for the shift in the threshold voltage <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${(}{V}_{\text {OFF}}{)}$ </tex-math></inline-formula> and two-dimensional electron gas (2-DEG) density due to the presence of buffer traps in the steady state are presented. In pulsed operation, technology computer-aided design (TCAD) simulations indicate that a time-dependent negative potential (NP) is developed under the gate, resulting in a modified <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {OFF}}$ </tex-math></inline-formula> and current collapse (CC). An expression for the modified <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {off}}$ </tex-math></inline-formula> helps capture the pulsed current–voltage characteristics. The model captures the dependence of bias, time, temperature, trap concentration, capture cross section area, and activation energy of traps on the steady-state and transient characteristics. The model is implemented in Verilog-A in an existing compact model framework using a diode and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RC</i> sub-circuit and validated using measured data and TCAD simulations. The modeling results are in excellent agreement with the experimental data and TCAD simulations. Since the model is physics-based, it requires fewer number of parameters compared to that in the existing models.

This work investigated the single-event effects (SEE) of NiO/β-Ga2O3 heterojunction diodes (HJDs) irradiated by 1.86 GeV tantalum ions with linear energy transfer over 80 MeV cm2/mg. The HJDs exhibited radiation responses with the early single-event leakage current (SELC) degradation until the fatal single-event burnout (SEB) failure, which was far below their breakdown voltages. Meanwhile, the surface morphology revealed the SELC damage expressed as burnout of topside NiO and metal stacks, while the SEB damage was observed as a burned hole in the β-Ga2O3 epitaxial layer. According to technology computer aided design simulations, the thicker p-type region in HJDs could further alleviate the electric field crowding effect exacerbated by the heavy-ion strike because of the extension of charge distribution in the p-type region. The SEB threshold was raised to 250 V by thickening the NiO layer to 300 nm. As for the SELC degradation process along with the burnout of topside stacks in HJDs, we supposed the probable reason was the intolerance of NiO to the high electric field under the SEE. This paper analyzed the SEE mechanism in β-Ga2O3 diodes and paved the way for heavy-ion irradiation hardening.

We report optical mixing with difference frequencies to 211 GHz in 50 nm gate pseudomorphic InP-based high electron mobility transistors (HEMTs). To our knowledge, this is the highest frequency optical mixing signal obtained in three terminal devices. To detect the signals at these frequencies, a novel three-wave-mixing configuration was employed. To demonstrate the wide tunability of this setup, a sweep of frequencies from 160 to 190 GHz was performed. The optically generated millimeter wave signals were downconverted to 97 GHz and radiated. For the radiation experiments, tunable baseband signals were also added by injection into the gate terminal of our HEMTs, thereby providing a method to transmit information.

An improved recessed-gate structure for high-performance short-gate InP-based InAlAs/InGaAs high electron mobility transistors (HEMTs) is presented. The effective gate length of the HEMTs is found to be related to the electron density in the side-etched region between the gate and the ohmic capped region. The higher electron density in the side-etched region is efficiently suppresses the effective gate length. A new gate recess process, which consists of a sequence of wet-chemical etching and Ar-plasma etching, enables us to reduce the effective gate length. The new recessed-gate structure successfully provides improved performance with high uniformity. A cutoff frequency of 300 GHz is achieved even with 0.07-µm-gate HEMTs.

The dependence of 0.13µm NMOS single event transient on linear energy transfer (LET) is studied and integrated into a single event transient (SET) pulses fault injection model. A modified double exponential function with four parameters that are related to LET is used to fit the single event transient pulsed current. By translating into the LET-dependent model, it can predict the charge collection without Technology Computer Aided Design (TCAD) simulation when LET is changed. The SRAM unit is built using the proposed single event transient pulses fault injection model into the sensitive node, proving the practicability and reasonableness of the proposed fault injection model for circuit-level single-event effect (SEE) simulation.

Fin field effect transistor (FinFET) is a most widely used structure when the field effect transistor is scaled down to 30 nm or less. And there are few studies on single-event transient of FinFET devices with gate length below 30 nm. The single-event-transient on FinFET with gate length below 30 nm is worth studying. The single-event-transient responses of bulk FinFETs with 30 nm, 40 nm, 60 nm and 100 nm gate length are examined by using the pulsed laser and technology computer-aided design (TCAD) simulation in this article. First, we use the pulsed laser to ionize the gate of the FinFET device and detect the transient drain current of the FinFET device. The experimental results show that there are obvious platforms for the transient drain current tails of FinFETs with different gate lengths, and the platform current increases as the gate length of FinFET becomes shorter. The charges collected in the platform of FinFET devices with gate lengths of 100, 60, 40, and 30 nm are 34%, 40%, 51%, and 65% of the total charge collected in transient drain current, respectively. Therefore, when the FinFET device with the gate length below 100 nm, the platform current will seriously affect the device performance. Second, we use TCAD to simulate the heavy ion single-event effect of FinFET device and study the generation mechanism of platform region in transient drain current. The TCAD simulation explains this mechanism. Laser or heavy ions ionize high concentration electron-hole pairs in the device. The holes are quickly collected and the high concentration electrons are left under the FinFET channel. High concentration electrons conduct source and drain, generating the source-to-drain current at the tail of the transient drain current. Moreover the source-drain conduction enhances the electrostatic potential below the FinFET channel and suppresses high-concentration electron diffusion, making source-to-drain current decrease slowly and form the platform. The transient drain current tail has a long duration and a large quantity of collected charges, which seriously affects FinFET performance. This is a problem that needs studying in the single-event effect of FinFET device. It is also a problem difficult to solve when the FinFET devices are applied to spacecraft. And the generation mechanism of the transient drain current plateau region of FinFET device can provide theoretical guidance for solving these problems.

A 70 nm gate-length In 0.7 Ga 0.3 As/In 0.52 Al 0.48 As InP-based high electron mobility transistor (HEMT) was successfully fabricated with a gate width of 2×20μm and source-drain space of 2 μm. The T-shaped gate with a stem height of 200nm is fabricated to minimize parasitic capacitance. The fabricated devices exhibited a maximum drain current density of 720 mA/mm (V GS =0.2V) and a maximum peak extrinsic-transconductance of 1600 mS/mm. The current gain extrinsic cutoff frequency f T and the maximum oscillation frequency f max were 310 and 540 GHz, respectively. The HEMTs are promising for use in THz-wave integrated circuits.

A key point in SEE (Single Event Effect) simulation experiment is how to calculate the equivalent LET (Linear Energy Transfer) for laser pulse. In this paper, the calculation method considering the influences of nonlinear absorption in semiconductor, reflection and refraction on device surface and other factors is presented. Simultaneously an instance of calculation is provided, with the result in good agreement with the SEU (Single Event Upset) threshold measured by heavy ions.

Toward the realization of ultra-fast wireless communications systems, the inherent broad bandwidth of the terahertz (THz) band is attracting attention, especially for short-range instant download applications. In this paper, we present our recent progress on InP-based THz MMICs and packaging techniques based on low-temperature co-fibered ceramic (LTCC) technology. The transmitter MMICs are based on 80-nm InP-based high electron mobility transistors (HEMTs). Using the transmitter packaged in an E-plane split-block waveguide and compact lens receiver packaged in LTCC multilayered substrates, we tested wireless data transmission up to 27 Gbps with the simple amplitude key shifting (ASK) modulation scheme. We also present several THz antenna-in-packaging solutions based on substrate integrated waveguide (SIW) technology. A vertical hollow (VH) SIW was applied to a compact medium-gain SIW antenna and low-loss interconnection integrated in LTCC multi-layer substrates. The size of the LTCC antennas with 15-dBi gain is less than 0.1 cm3. For feeding the antenna, we investigated an LTCC-integrated transition and polyimide transition to LTCC VH SIWs. These transitions exhibit around 1-dB estimated loss at 300 GHz and more than 35 GHz bandwidth with 10-dB return loss. The proposed package solutions make antennas and interconnections easy to integrate in a compact LTCC package with an MMIC chip for practical applications.

InP-based high electron mobility transistors (HEMTs) will be affected by protons from different directions in space radiation applications. The proton irradiation effects on InAlAs/InGaAs hetero-junction structures of InP-based HEMTs are studied at incident angles ranging from 0 to 89.9° by SRIM software. With the increase of proton incident angle, the change trend of induced vacancy defects in the InAlAs/InGaAs hetero-junction region is consistent with the vacancy energy loss trend of incident protons. Namely, they both have shown an initial increase, followed by a decrease after incident angle has reached 30°. Besides, the average range and ultimate stopping positions of incident protons shift gradually from buffer layer to hetero-junction region, and then go up to gate metal. Finally, the electrical characteristics of InP-based HEMTs are investigated after proton irradiation at different incident angles by Sentaurus-TCAD. The induced vacancy defects are considered self-consistently through solving Poisson’s and current continuity equations. Consequently, the extrinsic transconductance, pinch-off voltage and channel current demonstrate the most serious degradation at the incident angle of 30°, which can be accounted for the most severe carrier sheet density reduction under this condition.