Performance comparison of state-of-the-art heterojunction bipolar devices (HBT) based on AlGaAs/GaAs, Si/SiGe and InGaAs/InP

This paper presents a comprehensive comparison of three state-of-the-art heterojunction bipolar transistors (HBTs); the AlGaAs/GaAs HBT, the Si/SiGe HBT and the InGaAs/InP HBT. Our aim in this paper is to find the potentials and limitations of these devices and analyze them under common Figure of Merit (FOM) definitions as well as to make a meaningful comparison which is necessary for a technology choice especially in RF-circuit and system level applications such as power amplifier, low noise amplifier circuits and transceiver/receiver systems. Simulation of an HBT device with an HBT model instead of traditional BJT models is also presented for the AlGaAs/GaAs HBT. To the best of our knowledge, this work covers the most extensive FOM analysis for these devices such as I-V behavior, stability, power gain analysis, characteristic frequencies and minimum noise figure. DC and bias point simulations of the devices are performed using Agilent's ADS design tool and a comparison is given for a wide range of FOM specifications. Based on our literature survey and simulation results, we have concluded that GaAs based HBTs are suitable for high-power applications due to their high-breakdown voltages, SiGe based HBTs are promising for low noise applications due to their low noise figures and InP will be the choice if very high-data rates is of primary importance since InP based HBT transistors have superior material properties leading to Terahertz frequency operation.     

DC and microwave noise transient behavior of InP/InGaAs doubleheterojunction bipolar transistor (DHBT) with polyimide passivation

DC and microwave noise transient behavior of InP/InGaAs double heterojunction bipolar transistor (DHBT) with polyimide passivation is reported in this paper for the first time. The base transient current is believed to be due to the change of surface potential near the base-emitter junction perimeter at the polyimide/emitter interface resulting from a decrease in the amount of trapped electrons in the polyimide. We also find that the surface potential on the sidewall of collector-emitter affected by the charge trapping and detrapping in polyimide may induce a parasitic polyimide field effect transistor along the surface of the base-collector junction which results in an excess collector transient current. These base and collector current transients result in associated transient of broadband shot noise. The time dependence of microwave noise figures due to the excess transients is also investigated. The better understanding of the mechanisms of the noise transient behavior of the InP HBT device is very useful to improve the device and circuit reliability     

Hemt’s capability for millimeter wave applications

This paper presents a tutorial review on the High Electron Mobility Transistors (HEMTs)for low-noise and power applications at millimeter wave range frequencies. The major parameters to achieve high performance with such devices are discussed. Present status on power and noise performances is given for InAlAs/InGaAs HEMTs on InP and GaAs substrates.     

InGaAs avalanche photodiodes for 1 ?m wavelength region

A low-noise, low-dark-current and high-speed InGaAs avalanche photodiode (APD) has been designed and fabricated. The diode has a planar structure and is composed of InP/InGaAsP/InGaAs/InP layers grown on (111)A oriented InP. At a multiplication of 10, the diode exhibited excess noise factor of 5 and cutoff frequency of more than 1 GHz. Dark current was 10 nA near breakdown voltage. The diode has been tested in an experimental optical receiver in the gigabit range (time slot 0.63 ns) and 1.3 ?m. The receiver sensitivity of ?29.2 dBm was obtained at an error rate of 10?11.     

Ultralow-noise W-band pseudomorphic InGaAs HEMT's

Low-noise planar doped pseudomorphic (PM) InGaAs high-electron-mobility transistors (HEMTs) with a gate length of 0.1 μm for W-band operation are discussed. These devices feature a multiple-finger layout with air bridges interconnecting the sources to reduce gate resistance. The device exhibits a minimum noise figure of 2.5 dB with an associated gain of 4.7 dB at 92.5 GHz. This result demonstrates the feasibility of using PM InGaAs HEMTs for W-band low-noise receivers without the need for using lattice-matched InP HEMTs     

Temperature dependence of DC characteristics of NpN InP/GaAsSb/InP double heterojunction bipolar transistors: an analytical study

An analytic study of DC characteristics based on the drift-diffusion approach has been performed for the InP/GaAsSb DHBTs. The current transport of InP/GaAsSb/InP DHBTs has been investigated focusing the device temperature dependence. Our simulation results show that, at room temperature, the DC characteristics of the InP/GaAsSb/InP DHBTs similar to the conventional InP-based HBT using InGaAs as the base layer although a type-II energy band alignment is presented in the InP/GaAsSb HBT. However, due to different mechanisms for the electron injection from the emitter induced by the different conduction band alignments, the InP/GaAsSb HBTs may present a different temperature dependent behavior in term of device current gain as compared to the conventional InP/InGaAs HBTs. Higher current gain could be achieved by the InP/GaAsSb HBTs at elevated temperature.     

准平面型InAlAs/InGaAs异质结双极晶体管和单片集成激光器驱动电路

提出和制作了准平面型InAlAs/InGaAs异质结双极晶体管。该管主要采用硅离子注入法在半绝缘磷化铟衬底中形成隐埋型集电区以代替台面型集电区。晶体管的实测结果如下:h_(fe)=100,f_T=10GHz(V_(CE)=3V,I_c=10mA)。作为单片光电集成方面的实例,研制成功了由三个InGaAs/InAlAsHBT和一个电阻组成的激光器驱动电路,其电流调制速率高达4Gbit/s。     

Over 40 Gbit/s 16:1 multiplexer IC using InP/InGaAs HBT technology

A low-power 16:1 multiplexer (MUX) IC using undoped-emitter InP/InGaAs heterojunction bipolar transistors (HBTs) has been successfully designed and fabricated. To minimise power consumption, the collector current density of each HBT was optimised taking into account the required operating speed and the number of fan-outs. Up to 47 Gbit/s error-free operation was confirmed with low power consumption of about 3.2 W. These results demonstrate that InP/InGaAs HBT technology is attractive for fabricating over 40 Gbit/s, low-power medium-scale-integration (MSI) circuits.     

InP/InGaAs异质结双极晶体管研究

阐述了ＩｎＰ／ＩｎＧａＡｓ异质结双极晶体管的最新发展动态,重点讨论了ＨＢＴ的结构与性能以及ＨＢＴＩＣ的高速性能与可靠性问题     

A 1-17-GHz InGaP-GaAs HBT MMIC analog multiplier and mixer with broad-band input-matching networks

An InGaP-GaAs heterojunction bipolar transistor (HBT) analog multiplier/mixer monolithic microwave integrated circuit (MMIC) is developed that adopts a Gilbert-cell multiplier with broad-band input-matching networks to widen the bandwidth up to 17 GHz. This MMIC was fabricated using a commercially available 6-in InGaP-GaAs HBT MMIC process. It achieved a measured sensitivity of above 1100 V/W for an analog multiplier and a conversion gain of better than 9 dB for a mixer. It also demonstrated a lower corner frequency and noise than that of an InP HBT analog multiplier. The measured low-frequency noise was 10 nV/sqrt(Hz), which is about half of that of an InP HBT analog multiplier with a similar architecture. The corner frequency of the low-frequency noise was roughly estimated to be 15 kHz. The measured performance of this MMIC chip with gain-bandwidth-product (GBP) of 47 GHz rivals that of the reported GaAs-based analog multipliers and mixers. The high GBP result achieved by this chip is attributed to the HBT device performance and the broad-band input-matching network.     

Analysis of the transistor-related noise in integrated p-i-n-HBToptical receiver front-ends

The equivalent-input-noise-current spectral density for a monolithically integrated optical receiver front-end using InP/InGaAs heterojunction bipolar transistors and a p-i-n photodiode is computed from a small-signal model. Particular attention is paid to the contributions to the noise from the HBT in the first stage of the amplifier. It is shown that with transistors designed for 1-10-Gb/s receivers the base current shot noise dominates in the frequency range from 10 MHz to 1 GHz, and both the base resistance thermal noise and the collector current shot noise are important at higher frequencies. Device features which determine the extent of these noise sources are identified, and ways to improve the noise performance are discussed     

用于单片集成光接收机前端的GaAs基InP/InGaAs HBT

实现了一种可用于单片集成光接收机前端的GaAs基InP/InGaAs HBT。借助超薄低温InP缓冲层在GaAs衬底上生长出了高质量的InP外延层。在此基础上,只利用超薄低温InP缓冲层技术就在半绝缘GaAs衬底上成功制备出了InP/InGaAsHBT,器件的电流截止频率达到4.4GHz,开启电压0.4V,反向击穿电压大于4V,直流放大倍数约为20。该HBT器件和GaAs基长波长、可调谐InP光探测器单片集成为实现适用于WDM光纤通信系统的高性能、集成化光接收机前端提供了一种新的解决方法。     

InP/InGaAs heterojunction bipolar transistors with different g-bridge structures

Several μ-bridge structures for InP-based heterojunction bipolar transistors (HBTs) are reported. The radio frequency measurement results of these InP HBTs are compared with each other. The comparison shows that μ-bridge structures reduce the parasites and double μ-bridge structures have a better effect. Due to the utilization of the double μ-bridges, both the cutoff frequency f_T and also the maximum oscillation frequency f_(max) of the 2×12.5 μm~2 InP/InGaAs HBT reach nearly 160 GHz. The results also show that the μ-bridge has a better effect in increasing the high frequency performance of a narrow emitter InP HBT.     

Simulated study on the InP/InGaAs DHBT under proton irradiation

A 3D model simulation of InP/InGaAs/InP DHBT is reported in this paper. A comprehensive set of built-in physical models are described, including Stratton''s hydrodynamic model, high-fields mobility model and thermionic emission model. A mixed-mode environment is required for AC simulation instead of simulating an isolated HBT, in which the HBT is embedded in an external circuit, and the circuit voltage and current equations are solved along with the Poisson equation and transport equations. In AC simulation, simulator Sentaurus provides the computation of the small signal admittance Y matrix. From the results of Y matrix, the small signal equivalent circuit is constructed with the conductance and capacitance obtained from Y matrix, and the AC parameters, such as S-parameters, will be calculated. The small signal AC characteristics of InP/InGaAs DHBTs under proton irradiation are simulated with different fluences of proton irradiation. Simulation results show that the maximum oscillation frequency will be degraded when fluence of proton irradiation is increased.     

InGaAs/InP double-heterostructure bipolar transistors with near-ideal β versus ICcharacteristic

InGaAs/InP double-heterostructure bipolar transistors (DHBT's) with current gain β ∼ 630 have been realized using gas-source molecular beam epitaxy (GSMBE). These devices exhibit near-ideal β versus ICcharacteristic (i.e., β independent of IC) with a small-signal gainh_{fe} sim 180atI_{C} sim 2nA. In comparison, we findbeta sim I_{C}^{0.5}for a high-quality AlGaAs/GaAs HBT grown by OMCVD. The higher emitter injection efficiency at low collector current levels found in the InGaAs/InP DHBT is due to at least a factor 100 smaller surface recombination current.     

An analytic procedure for extraction of metallic collector-up InP/InGaAsP/InGaAs HBT small signal equivalent circuit parameters

A parameter extraction procedure for determining an improved T-topology small signal equivalent circuit of a metallic collector-up HBT with composite base is presented. The proposed T-small signal equivalent circuit includes base and collector impedances modelled by parallel RC circuits. The new technique employs analytically derived expressions for direct calculation of HBT T-Model equivalent circuit element values in terms of the measured S-parameters. This approach avoids errors due to uncertainty in fitting to large, over determined equivalent circuits and does not require the use of test structures and extra measurement steps to evaluate parasitics. Physically realistic results are demonstrated under various biasing conditions for the n–p–n InP/InGaAsP/InGaAs composed base HBT with metallic collector-up structure (C-up MHBT). The agreement between the measured and model-produced data is excellent over the large frequency range and for several polarizations conditions for devices.     

47.8 GHz InP HBT quadrature VCO with 22% tuning range

A 38-47.8 GHz quadrature voltage controlled oscillator (QVCO) in InP HBT technology is presented. The measured output power is -15 dBm. The simulated phase noise ranges from -84 to -86 dBc/Hz at 1 MHz offset. It is believed that this is the first millimetre-wave QVCO implemented in InP HBT technology as well as the highest measured oscillation frequency for any QVCO     

Preliminary results of storage accelerated aging test on InP/InGaAs DHBT

We report on the reliability of InP HBT technology which has applications in very high-speed ICs. This work presents the storage accelerated aging tests results performed on InP/InGaAs HBT at stress temperatures of 180, 210 and 240 °C up to 3000 h. We have performed aging tests for two generations of InP HBT which differ from the collector doping level and from material used for planarization. From the Gummel plots, we note that the major degradation mechanism is located at the base–emitter junction periphery. Investigations on the physical origin of the observed failure mechanism has been performed using TCAD simulations.     

Fabrication of Transimpedance Amplifier Module and Post‐Amplifier Module for 40 Gb/s Optical Communication Systems

The design and performance of an InGaAs/InP transimpedance amplifier and post amplifier for 40 Gb/s receiver applications are presented. We fabricated the 40 Gb/s transimpedance amplifier and post amplifier using InGaAs/InP heterojunction bipolar transistor (HBT) technology. The developed InGaAs/InP HBTs show a cut‐off frequency (f_T) of 129 GHz and a maximum oscillation frequency (f_max) of 175 GHz. The developed transimpedance amplifier provides a bandwidth of 33.5 GHz and a gain of 40.1 dBΩ. A 40 Gb/s data clean eye with 146 mV amplitude of the transimpedance amplifier module is achieved. The fabricated post amplifier demonstrates a very wide bandwidth of 36 GHz and a gain of 20.2 dB. The post‐amplifier module was fabricated using a Teflon PCB substrate and shows a good eye opening and an output voltage swing above 520 mV.     

MBE生长的InP DHBT的性能

报道了一种自对准InP/InGaAs 双异质结双极晶体管的器件性能.成功制作了U型发射极尺寸为2μm×12μm的器件,其峰值共射直流增益超过300,残余电压约为0.16V,膝点电压仅为0.6V,而击穿电压约为6V.器件的截至频率达到80GHz,最大震荡频率为40GHz.这些特性使此类器件更适合于低压、低功耗及高频方面的应用.