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The extraction of small‐signal parameters is of great importance for the modeling of InP heterojunction bipolar transistors (HBTs). This letter proposes an improved small‐signal parameter extraction method that considers both the emitter–collector capacitance effect and the current crowding effect. The corresponding parameter extraction procedure based on closed‐form equations is outlined. Furthermore, the model parameter extraction method is validated using two different‐sized InP HBT devices with multibias S‐parameters. The results demonstrate that the established small‐signal model exhibits greater than 90% accuracy across the frequency range of 1–110 GHz. In particular, in the high‐frequency band (above 50 GHz), the proposed model exhibits an improvement in accuracy of 7.4% after considering the emitter–collector capacitance and current crowding effects. This method can contribute to accurate modeling of the noise and large‐signal performance of InP HBT. [ABSTRACT FROM AUTHOR]

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A model of the position of the edge of emitter-base junction in the base and collector current pre-exponential ideality factor in HBT transistor with a SiGe base is presented. The model is valid for transistors with nonuniform profiles of doping and Ge content. The importance of taking into account the dependence of the effective density of states in SiGe on local Ge content and that of electron diffusion coefficient in SiGe on drift field for modeling accuracy is studied.

We investigate the angular dependence of proton-induced single event transient (SET) in silicon-germanium heterojunction bipolar transistors. Experimental results show that the overall SET cross section is almost independent of proton incident angle. However, the proportion of SET events with long duration and high integral charge collection grows significantly with the increasing angle. Monte Carlo simulations demonstrate that the integral cross section of proton incident events with high ionizing energy deposition in the sensitive volume tends to be higher at larger incident angles, which is associated with the angular distribution of proton-induced secondary particles and the geometry of sensitive volume. [ABSTRACT FROM AUTHOR]

Monolithic microwave integrated circuits hold a dominant position in telecom applications, especially in mobile devices with capabilities for wireless connectivity, due to high and repeatable performance, compact form factor, and low cost. With flexible electronic technologies forming the foundation for a rapidly growing wearable and implantable device segment, the need for flexible microwave electronics with levels of performance that match those of rigid counterparts has increased to unprecedented levels. Here, the fabrication processes for transforming a rigid form of foundry‐produced, multilayered monolithic microwave integrated circuit into a flexible format for amplification of radio frequency signals in the gigahertz level are described. The strategy involves a complete replacement of all rigid materials in the integrated circuit that do not provide any active electronic functionality with a soft, silicone elastomer to yield an overall structure that is mechanically compliant. Experimental studies indicate that the transformation process leads to a flexible silicon‐germanium‐based heterojunction bipolar transistor with a maximum oscillation frequency of 49 GHz and a 24 GHz amplifier with a small‐signal gain of 13.2 dB. This approach has potential uses across a diverse set of microwave devices and circuits, in a manner that could enable wireless connectivity using entirely flexible electronics. [ABSTRACT FROM AUTHOR]

In this paper, the dynamic response of the optical gain of optical integrated device composed of a heterojunction bipolar transistor (HBT) and a laser diode (LD) has been numerically analyzed. This type of optical integrated device is called transistor laser (TL). First, the rate equation of LD has been solved to obtain its transfer function. Second, the overall transfer function of the whole structure has been analyzed numerically. The effect of HBT cutoff frequency on the amplitude and phase frequency response has been studied. The obtained results show that HBT has a strong influence on the device performance. In particular, higher values of HBT cutoff frequency result in lower amplitudes and higher phase values in the low-frequency range. The device is stable and has a fast response and high optical gain at higher frequencies. Therefore, it can be used as an optical amplifier or optical switch in high-speed optical systems. [ABSTRACT FROM AUTHOR]

This paper presents an analytical model of an infrared thermal imaging device. This device is composed of a Quantum Well Infrared Photodetector (QWIP), a Heterojunction Bipolar transistor (HBT) and a Light Emitting Diode (LED). It is called as QWIP-HBT-LED Optoelectronic Integrated Device. The device is modeled based on its equivalent circuit by considering a nonlinear gain HBT, early effect. Analytical expressions describing the current time response, rise time, and output derivative as a measure of device speed have been derived. The numerical results show that the transient performance of this device version is enhanced by the injected current from QWIP to the base of HBT, also the output current is increased with the increase of the gain and early coefficient of HBT, on the other hand, it degrades when the base recombination factor of HBT or the load resistance is increased. Also, the rise time increases when the current gain or the early coefficient is increased. This type of models can be exploited as a pixel in thermal image processing applications. [ABSTRACT FROM AUTHOR]

We report the performances of a 0.7-μm InP/GaInAs DHBT developed in III-V Lab demonstrating both fT and f MAX of 400 GHz as well as a high fabrication yield and homogeneity on a 3-inch wafer. This technology is used for the fabrication of a very high speed 2:1 multiplexing selector operating up to 212-Gb/s, establishing a speed record. A 5.4-Vpp 100-Gb/s distributed differential selector-driver, as well as a 4.3-Vpp 64-GBd 8-pulse-amplitude-modulation (PAM) (192 Gb/s) high-speed power digital-to-analog converter (DAC) were also realized in this technology.

Accurate detection of quantum states is a vital step in the development of quantum computing. Image-charge detection of quantum states of electrons on liquid helium can potentially be used for the readout of a single-electron qubit; however, low sensitivity due to added noise hinders its usage in high-fidelity and high-bandwidth (BW) applications. One method to improve the readout accuracy and bandwidth is to use cryogenic amplifications near the signal source to minimize the effects of stray capacitance. We experimentally demonstrate a two-stage amplification scheme with a low power dissipation of 90 μ W at the first stage located at the still plate of the dilution refrigerator and a high gain of 40 dB at the second stage located at the 4 K plate. The good impedance matching between different stages and output devices ensures high BW and constant gain in a wide frequency range. The detected image-charge signals are compared for one-stage and two-stage amplification schemes. [ABSTRACT FROM AUTHOR]

This review paper reports the prerequisites of a monolithic integrated terahertz (THz) technology capable of meeting the network capacity requirements of beyond-5G wireless communications system (WCS). Keeping in mind that the terahertz signal generation for the beyond-5G networks relies on the technology power loss management, we propose a single computationally efficient software design tool featuring cutting-edge optical devices and high speed III–V electronics for the design of optoelectronic integrated circuits (OEICs) monolithically integrated on a single Indium-Phosphide (InP) die. Through the implementation of accurate and SPICE (Simulation Program with Integrated Circuit Emphasis)-compatible compact models of uni-traveling carrier photodiodes (UTC-PDs) and InP double heterojunction bipolar transistors (DHBTs), we demonstrated that the next generation of THz technologies for beyond-5G networks requires (i) a multi-physical understanding of their operation described through electrical, photonic and thermal equations, (ii) dedicated test structures for characterization in the frequency range higher than 110 GHz, (iii) a dedicated parameter extraction procedure, along with (iv) a circuit reliability assessment methodology. Developed on the research and development activities achieved in the past two decades, we detailed each part of the multiphysics design optimization approach while ensuring technology power loss management through a holistic procedure compatible with existing software tools and design flow for the timely and cost-effective achievement of THz OEICs. [ABSTRACT FROM AUTHOR]

Copyright of Electronic Components & Materials is the property of Electronic Components & Materials and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this article, an improved layout design and a base‐collector undercut etching process have been proposed and demonstrated for a high‐speed InP/InGaAs heterojunction bipolar transistor (HBT). The fabricated HBT using proposed methods has a smaller parasitic base‐collector (B‐C) area, resulting in reduced B‐C capacitance (CBC), a reduction of 36% compared to that in the conventional HBT. A current gain cutoff frequency (fT) and a maximum oscillation frequency (fmax) of the proposed HBT have been increased from 110 to 131 GHz and from 112 to 131 GHz due to the reduced CBC. These results clearly show the effectiveness of the proposed technique for the HBTs. [ABSTRACT FROM AUTHOR]

Analytical expressions for the short‐circuit current gain and unilateral power gain of common emitter heterojunction bipolar transistor (HBT) are presented in this paper. These expressions are derived from a simplified π‐type small signal equivalent circuit model, which takes into account the influence of the extrinsic resistances and base‐collector capacitance distributed nature. Good agreement is obtained between measured and calculated results for both two indium phosphide (InP) HBT devices and a gallium arsenide (GaAs) HBT device over a wide range of bias points. [ABSTRACT FROM AUTHOR]

The effects of gamma irradiation on the DC and AC characteristics of InGaP/GaAs single heterojunction bipolar transistors (SHBTs) are investigated comprehensively for the first time, which is based on experimental data before irradiation, after irradiation and after annealing. A simplified VBIC device model is developed to describe the DC and AC characteristics of the devices. The model parameters are extracted from experimental data before irradiation, after irradiation and after annealing. Finally, the degraded rates of model parameters are used to study the radiation-induced degradation of the device performance. [ABSTRACT FROM AUTHOR]

InP/InGaAs/InP double heterojunction bipolar transistors (DHBT) have been designed for increased bandwidth digital and analog circuits, and fabricated using a conventional mesa structure. These devices exhibit a maximum 450 GHz f,tau and 490 GHz f,max, which is highest simultaneous f,tau and f,max for any HBT. The devices have been scaled vertically for reduced electron collector transit time and aggressively scaled laterally to minimize the base-collector capacitance associated with thinner collectors. The DC current gain beta is ~ 40 and BVCEO = 3.9 V. The devices operate up to 25 mW/um^2 dissipation (failing at Je = 10 mA/um^2, Vce = 2.5 V, delta T,failure = 301 K) and the there is no evidence of current blocking up to Je = 12 mA/um^2 at V,ce = 2.0 V from the base-collector grade. The devices reported here employ a 30 nm highly doped InGaAs base, and a 120 nm collector containing an InGaAs/InAlAs superlattice grade at the base-collector junction.

Copyright of Electronic Components & Materials is the property of Electronic Components & Materials and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electronic Components & Materials is the property of Electronic Components & Materials and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We demonstrate simultaneous electrical and optical modulations of the first GaN/InGaN quantum-well light-emitting transistor (QW-LET) which contains an In0.15 Ga0.85N QW in the heavily p-doped In0.05 Ga0.95N base. Unlike GaAs/InGaAs counterparts, the GaN/InGaN QW- LET has a current gain (up to 5) and optical power which increases linearly with the base current. Its emission spectra are centered at a wavelength of 420 nm and barely shift with the current injection, in contrast to the behavior of typical nitride-based LEDs. The unusual features of this device may be related to the tilted band profile induced by the polarization field in the QW and issue of p-type doping. [ABSTRACT FROM AUTHOR]

This paper aims to evaluate the base–emitter forward characteristics of In0.52Al0.48As/In0.53Ga0.47As heterojunction bipolar transistors using numerical simulations in Silvaco while comparing results with fabricated devices. Analysis drawn from simulations reveals that in addition to doping, thickness of emitter and spacer region also plays an important role in determining the operational behaviour of device. The thickness of spacer region strongly influences the nature of heterojunction barrier formed that in turn controls the injection efficiency and dictates various recombination mechanisms. Even a few angstroms added to a spacer layer can cause considerable shift in DC characteristics. Methodology of device modelling is first validated by matching simulated results with the experimental measurements of two different structures. Spacer thickness and emitter doping is then varied in each of the structures to comprehensively study the effect of these variations onto important DC figures of merit. [ABSTRACT FROM AUTHOR]

Electrical transport across the poly/monocrystalline silicon (poly-Si/c-Si) interface has been investigated by introducing variations in the interface treatment process affecting the thickness of the native oxide layer formed on the silicon surface. The I-V relationship characterizing the resistance associated with this interface is extracted using an improved open-collector method, which eliminates the inherent nonlinearity arising from the reverse active characteristics of the bipolar transistor. The nonohmic behavior of the interface at low electric fields is demonstrated to be consistent with direct tunneling through a rectangular barrier presented by an ultrathin interfacial oxide layer. An approximate tunnel junction model is proposed that fits the tunneling current in the low bias regime, predicting the experimentally observed increase in the low-voltage leakage current associated with ultrathin oxides. The thickness of the interfacial oxide extracted by fitting the measured data to the proposed rectangular-barrier tunnel junction model is in good agreement with reported experimental values. Finally, a relation between experimentally introduced variations in the interface treatment process and the magnitude of the resistance associated with the interface is identified, which can be quantitatively explained based on the direct tunnel junction model in terms of differences in the native oxide thickness. [ABSTRACT FROM AUTHOR]

We propose the design and analysis of a group-IV material-based (Ge0.84Sn0.16/Si0.09Ge0.8Sn0.11) multiple quantum wells (MQW) transistor laser (TL) for mid-infrared applications. The base region incorporates Ge0.84Sn0.16/Si0.09Ge0.8Sn0.11 MQW structures pseudomorphically grown on silicon through GeSn virtual substrate, compatible with CMOS platforms for cost-effective integration of electronic and photonic circuits. With the introduction of a certain amount of tin (α-Sn) content (Sn > 6%) into germanium (Ge), GeSn alloy shows direct bandgap, thereby achieving the population inversion condition. In addition, the use of MQW structures such as the active region enhances gain due to quantum–confinement effects, and better carrier utilization over its bulk counterpart. A comparison is made between the theoretical finding for the proposed Ge0.84Sn0.16 MQW TL and the available experimental and theoretical data for currently employed InGaAs-based single quantum well (SQW) and MQW TLs. Estimated results show that a lower threshold base current of ∼ 2.65 mA and high modulation BW of ∼ 53 GHz can be achieved, which ensures the proposed GeSn-based MQW TL can be a good alternative for III–V-based TL. [ABSTRACT FROM AUTHOR]

Highlights • Heterojunction bipolar transistor solar cells with non-ideal effects are studied. • Simpler structure and fabrication compared with dual-junction solar cells. • High conversion efficiency can be achieved at low solar concentrations. • Low injection efficiency and working temperature provide better performance. • Paving a route towards the development of low-cost high-performance solar cells. Abstract Without fabricating intermediate tunnel junctions or wafer bonding schemes for interconnecting the subcells, heterojunction bipolar transistor solar cells offer a promising new route in solar energy conversion. In this work, an improved theory for the three-terminal heterojunction bipolar transistor solar cell is presented with inclusion of non-ideal effects missing from the previous treatment, namely the non-radiative recombination and the thermal conduction losses that are inevitably present in realistic devices. Following detailed balance theory, the revised analytical formula for the cell conversion efficiency is derived, and the maximum efficiencies under different conditions are further calculated. Under the condition of 100 sun irradiance and 50% injection efficiency, a Gallium arsenide/Gallium antimonide-based solar cell operating at 465 K yields a maximum efficiency of 46.4%. Moreover, the effects of solar concentration, injection efficiency, and other key parameters on the cell performance are analyzed, and, consequently, optimal operating conditions and limiting factors on the conversion efficiency are determined. Simulation results show that such a solar cell operating with low injection efficiency under moderate concentration factor and low cell temperature can significantly boost its conversion performance. This work provides new physical insights for optimal designs, thus paving a route towards the development of low-cost high-performance solar cells. [ABSTRACT FROM AUTHOR]

This review paper reports the prerequisites of a monolithic integrated terahertz (THz) technology capable of meeting the network capacity requirements of beyond-5G wireless communications system (WCS). Keeping in mind that the terahertz signal generation for the beyond-5G networks relies on the technology power loss management, we propose a single computationally efficient software design tool featuring cutting-edge optical devices and high speed III–V electronics for the design of optoelectronic integrated circuits (OEICs) monolithically integrated on a single Indium-Phosphide (InP) die. Through the implementation of accurate and SPICE (Simulation Program with Integrated Circuit Emphasis)-compatible compact models of uni-traveling carrier photodiodes (UTC-PDs) and InP double heterojunction bipolar transistors (DHBTs), we demonstrated that the next generation of THz technologies for beyond-5G networks requires (i) a multi-physical understanding of their operation described through electrical, photonic and thermal equations, (ii) dedicated test structures for characterization in the frequency range higher than 110 GHz, (iii) a dedicated parameter extraction procedure, along with (iv) a circuit reliability assessment methodology. Developed on the research and development activities achieved in the past two decades, we detailed each part of the multiphysics design optimization approach while ensuring technology power loss management through a holistic procedure compatible with existing software tools and design flow for the timely and cost-effective achievement of THz OEICs.

This paper presents a commercial or industrial view of III–V compact models for circuit design. We contrast the requirements of III–V modeling to those of silicon. The differences in requirements are strongly rooted in the applications that III–V devices are used in the end user of III–V models and the differences in the “ecosystems” of the technologies. These differences create both challenges and opportunity for the III–V modeling community. [ABSTRACT FROM AUTHOR]

Abstract In the last decade it has become increasingly popular to use germanium enriched silicon in modern field effect transistors (FET) due to the higher intrinsic mobility of both holes and electrons in SiGe as compared to Si. Whether used in the source/drain region (S/D) as compressive stressor, which is an efficient mobility booster on Si channel devices, or as channel material, the SiGe increases channel carrier mobility and thus enhancing device performance. Because the germanium content modifies the effective bandgap energy E G , this material characteristic is an important technology performance parameter. The bandgap energy can be determined in an LED-like operation of electronic devices, requiring forward biased p-n junctions. P-n junctions in FETs are source or drain to body diodes, usually grounded or reversely biased. This investigation applies a bias to the body that can trigger parasitic forward operation of the source/drain to body p-n junction in any FET. Spectral photon emission (SPE) is used here as a non-destructive method to characterize engineered bandgaps in operative transistor devices, while the device remains fully functional. Before applying the presented technique to a p-type FinFET device, it is put to the proof by verifying the nominal silicon bandgap on an (unstrained) 120 nm technology FET. Subsequently the characterization capability for bandgap engineering is then successfully demonstrated on a SiGe:C heterojunction bipolar transistor (HBT). In a final step, the bandgap energy E G of a 14/16 nm p-type FinFET was determined to be 0.84 eV, which corresponds to a Si 0.7 Ge 0.3 mixture. The presented characterization technique is a contactless fault isolation method that allows for quantitative local investigation of engineered bandgaps in p-type FinFETs. [ABSTRACT FROM AUTHOR]

The characterization of SiGe diode-connected heterojunction bipolar transistors (HBTs) through measurements of two-circuit configurations is presented. Characterization is done to understand the behavior of these diodes for near-infrared detecting applications at room temperature and 77 K. The two configurations that are considered differ; the first is a base-emitter shorted HBT and the second is a base-collector shorted HBT. The parameters measured are current density-voltage, capacitance–voltage, and noise. The two configurations are implemented using the austriamicrosystems AG 0.35-μm process. The base-emitter shorted configuration exhibits a flatter JC versus V curve when in reverse bias compared with the base-collector configuration. The C  −  V curves are the same for both configurations. The noise voltage of the base-emitter configuration is 36 and 14.48  μV  /  √Hz at 102.5 Hz for 293 and 77 K temperature points, respectively, to 14.48 and 12.42  μV  /  √Hz at 50 kHz for 293 and 77 K, respectively. The noise voltage for the base-collector configuration is 12.6 and 7.56  μV  /  √Hz at 102.5 Hz for 293 and 77 K, respectively, to 2.228 and 5.981  μV  /  √Hz at 50 kHz for 293 and 77 K, respectively. This work is done using a standard Si-based technology, where a detector array with readout circuitry can be prototyped as a single chip. The floating base transistor topology is analyzed and used as a foundation for this work. The characteristics of a floating base configuration result in a wide depletion region, large-series resistance, and small-series capacitance. When shorting the base with the emitter and collector, respectively, compared with a floating base configuration, a smaller depletion region, reduced series resistance, and larger series capacitance are observed. [ABSTRACT FROM AUTHOR]

A compact highly efficient high-power SiGe Ka-band balanced frequency doubler is presented. Using a compact single-footprint four-way transformer input balun, wideband matching, and high fundamental rejection were achieved simultaneously. A cascode topology with very low base impedance termination was utilized for stable operation and high-voltage swing at the output. Two cascode differential pairs form a common-centroid configuration, resulting strong enhancement in output power, power-added efficiency (PAE), fundamental rejection, and robustness to process and supply variation. The proposed Ka-band cascode balanced frequency doubler was implemented in a 0.13- $\mu \text{m}$ SiGe BiCMOS technology. Measured results show 13-dBm output power with 22% peak PAE at 34 GHz for a −1-dBm input power. The 3-dB conversion gain bandwidth is from 25 to 40 GHz, fully covering Ka-band. Peak fundamental suppression is 74.5 dB at 33 GHz, and it is higher than 35 dB over Ka-band. No performance degradation is observed after 24-h RF stress test. To the author’s best knowledge, this paper has the highest efficiency, the highest output power/power density, the highest conversion gain without output buffers, and the higher or comparable fundamental rejection among any Si-based frequency doublers. Therefore, this doubler will be a promising solution for efficient and high-power local oscillator generation in 5G wireless phased-array communication system. [ABSTRACT FROM AUTHOR]

The coherent photons generated at the base quantum wells in the transistor laser (TL) interact with the collector field and "assist" electron tunneling from the valence band of the base to the conduction band states of the collector. The cavity coherent photon intensity effect on photon-assisted tunneling in the TL has resulted in the realization of a novel photon-field enhanced optical absorption. This intra-cavity photon-assisted tunneling (ICPAT) in the TL or the light-emitting transistor is the unique property of voltage (field) modulation and the basis for ultrahigh speed direct tunneling photon modulation and switching. In addition, a new tunneling current modulation gain in a "new form" of transistor is discovered based on the collector tunneling holes feedback to the base and dielectric relaxation base transport. The TL, owing to its unique threeterminal configuration and the complementary nature of its optical and electrical collector output signals, enables fast base recombination, collector tunneling, and OEO feedback, which has resulted in the realization of compact electro-optical applications, such as non-linear signal-mixing, frequency multiplication, OE tunneling transistor, and electrical and optical bistability. [ABSTRACT FROM AUTHOR]