GaInP/GaAs double heterojunction bipolar transistor with highfT, fmax, and breakdown voltage

We report on the dc and microwave performance of an MOCVD-grown carbon-doped GaInP/GaAs double heterojunction bipolar transistor (DHBT) with a thin highly doped n-type GaInP layer in the collector. The DHBT showed improved current-voltage characteristics at low collector-emitter bias compared with those of a DHBT without the heavily doped GaInP layer, while maintaining a high breakdown voltage (BV_CEO~20 V). Small area, self-aligned emitter transistors with two 2×5 μm² emitter fingers were fabricated and exhibited f_T and f_max of 53 GHz and 75 GHz, respectively. These results indicate the promise of carbon-doped base GaInP/GaAs DHBT's for high-power microwave applications     

Analytical investigation of dead space effect under near-breakdown conditions in GaInP/GaAs composite double heterojunction bipolar transistors

The dead space effect under near-breakdown conditions in GaInP/GaAs composite collector double heterojunction bipolar transistor (DHBT) is investigated analytically. Using the dead space corrected model, the breakdown voltage is found to decrease with GaAs spacer thickness as reported from experiments. The common-mode emitter IV characteristics for the DHBT are simulated until the onset of multiplication with good agreement with reported experimental results [IEEE Elec. Dev. Lett. 15 (1994) 10]. A proposed optimised structure is simulated with comparably good turn-on I–V characteristics and improved breakdown performance.     

GaInP/AlGaAs/GaInP double heterojunction bipolar transistors withzero conduction band spike at the collector

Al_0.11Ga_0.89As was used in the base, next to the GaInP collector of a DHBT, to eliminate the conduction band spike. The DHBT's demonstrated high breakdown voltages, BV_CEO and BV _CBO of 44.5 V and 54.5 V (gain≈20), respectively, for a 1-μm-thick collector doped to 2×10¹⁶ cm^-3 with no voltage dependence of the current gain. Magneto-transport measurements were made on the AlGaAs bases and indicated limitations on the maximum practical base doping due to the inferior minority electron mobility and lifetime when compared with equivalently doped GaAs. Grading in the base from Al_0.11Ga_0.89As at the collector to Al_0.21Ga_0.79As at the emitter introduced a quasielectric field in the base, reduced the base transit time by a factor of ~2.5, and improved the gain over ungraded devices with the same average Al concentration     

基于MBE生长的一种Be掺杂InGaAs基区的新结构InGaP/InGaAs/GaAs DHBT

报道了一种以InGaAs为基区的新结构InGaP/InGaAs/GaAs双异质结晶体管,获得了直流性能良好的器件.其共射直流增益β达到100,残余电压Voffset约为0.4V,膝点电压Vknee约为1V,击穿电压BVceo超过10V,器件的基极和集电极电流理想因子分别为nb=1.16,nc=1.11,可应用于低功耗、高功率领域.     

新结构InGaP/GaAs/InGaP DHBT生长及特性研究

设计并生长了一种新的InGaP/GaAs/InGaP DHBT结构材料,采用在基区和集电区之间插入n+-InGaP插入层结构,以解决InGaP/GaAs/InGaP DHBT集电结导带尖峰的电子阻挡效应问题。采用气态源分子束外延(GSMBE)技术,通过优化生长条件,获得了高质量外延材料,成功地生长出带有n+-InGaP插入层结构的GaAs基InGaP/GaAs/InGaP DHBT结构材料。采用常规的湿法腐蚀工艺,研制出发射极面积为100μm×100μm的新型结构InGaP/GaAs/InGaP DHBT器件。直流特性测试的结果表明,所设计的集电结带有n+-InGaP插入层的InGaP/GaAs/InGaP DHBT器件开启电压约为0.15V,反向击穿电压达到16V,与传统的单异质结InGaP/GaAs HBT相比,反向击穿电压提高了一倍,能够满足低损耗、较高功率器件与电路制作的要求。     

Temperature-dependence investigation of a high-performance inverteddelta-doped V-shaped GaInP/InxGa1-xAs/GaAspseudomorphic high electron mobility transistor

A newly designed inverted delta-doped V-shaped GaInP/In_xGa_1-xAs/GaAs pseudomorphic high electron mobility transistor (PHEMT) has been successfully fabricated and studied. For a 1×100 μm² device, a high gate-to-drain breakdown voltage over 30 V at 300 K is found. In addition, a maximum transconductance of 201 mS/mm with a broad operation regime for 3 V of gate bias (565 mA/mm of drain current density), a very high output drain saturation current density of 826 mA/mm, and a high DC gain ratio of 575 are obtained. Furthermore, good temperature-dependent performances at the operating temperature ranging from 300 to 450 K are found. The unity current gain cutoff frequency f_T and maximum oscillation frequency f_max up to 16 and 34 GHz are obtained, respectively. Meanwhile, the studied device shows the significantly wide and flat gate bias operation regime (3 V) for microwave performances     

4.9-GHz low-phase-noise transformer-based superharmonic-coupled GaInP/GaAs HBT QVCO

The low-phase-noise GaInP/GaAs heterojunction bipolar transistor (HBT) quadrature voltage controlled oscillator (QVCO) using transformer-based superharmonic coupling topology is demonstrated for the first time. The fully integrated QVCO at 4.87GHz has phase noise of -131dBc/Hz at 1-MHz offset frequency, output power of -4dBm and the figure of merit (FOM) -198dBc/Hz. The state-of-the-art phase noise FOM is attributed to the superior GaInP/GaAs HBT low-frequency device noise and the high quality transformer formed on the GaAs semi-insulating substrate.     

Avalanche multiplication in GaInP/GaAs single heterojunctionbipolar transistors

The electron multiplication factors in GaInP/GaAs single heterojunction bipolar transistors (HBT's) have been measured as a function of base-collector bias for a range of GaAs collector doping densities. In the lowest doped (5×10¹⁴ cm^-3) thick collector the multiplication is determined by the local electric field. As the collector doping increases, the measured multiplication is found to be significantly reduced at low values of multiplication from that predicted by the electric field profile. However, good agreement is always found at high multiplication, close to breakdown. This reduction in multiplication at low electric fields is attributed to the dead space, the minimum distance over which carriers must travel before gaining the ionization threshold energy. A simple correction for the dead space is proposed, allowing the multiplication to be accurately predicted even in heavily doped structures     

Observation of resonant tunneling at room temperature inGaInP/GaAs/GaInP double-heterojunction bipolar transistor

Negative differential resistance (NDR) has been observed at room temperature in GaInP/GaAs double-heterojunction bipolar transistors (DHBTs). Both the common-emitter and common-base current-voltage characteristics and their magnetic field dependence have been studied to confirm that the observed NDR is due to resonant tunneling. The collector-base voltages at which the collector current resonances occur are calculated and are consistent with the measured values. The devices exhibit an offset voltage of 57 mV and saturation voltage of ⩽ 2-V, both of which are the lowest reported values for GaInP/GaAs DHBTs. The collector-base breakdown voltage in these DHBTs is 31 V, and its variation with junction temperature is measured and described     

GaInP/GaAs collector-up tunneling-collector heterojunction bipolar transistors (C-up TC-HBTs): optimization of fabrication process and epitaxial layer structure for high-efficiency high-power amplifiers

This paper describes a novel heterojunction bipolar transistor (HBT) structure, the collector-up tunneling-collector HBT (C-up TC-HBT), that minimizes the offset voltage V/sub CE,sat/ and the knee voltage V/sub k/. In this device, a thin GaInP layer is used as a tunnel barrier at the base-collector (BC) junction to suppress hole injection into the collector, which results in small V/sub CE,sat/. Collector-up configuration is used because of the observed asymmetry of the band discontinuity between GaInP and GaAs depending on growth direction. To minimize V/sub k/, we optimized the epitaxial layer structure as well as the conditions of ion implantation into the extrinsic emitter and post-implantation annealing. The best results were obtained when a 5-nm-thick 5/spl times/10/sup 17/-cm/sup -3/-doped GaInP tunnel barrier with a 20-nm-thick undoped GaAs spacer was used at the BC junction, and when 2/spl times/10/sup 12/-cm/sup -2/ 50-keV B implantation was employed followed by 10-min annealing at 390/spl deg/C. Fabricated 40/spl times/40-/spl mu/m/sup 2/ C-up TC-HBTs showed almost zero V/sub CE,sat/ (<10 mV) and a very small V/sub k/ of 0.29 V at a collector current density of 4 kA/cm/sub 2/, which are much lower than those of a typical GaInP/GaAs HBT. The results indicate that the C-up TC-HBT's are attractive candidates for high-efficiency high power amplifiers.     

A comparative study of GaInP/GaAs heterojunction bipolartransistors grown by CBE using TBA/TBP andAsH3/PH3 sources

GaInP/GaAs heterojunction bipolar transistors (HBT's) have been fabricated on epitaxial layers grown by chemical beam epitaxy (CBE) using an all metalorganic approach. Reduced toxicity tertiarybutylarsine (TBA) and tertiarybutylphosphine (TBP) were used for group V sources. DC results showed good base and collector current ideality factors of 1.23 and 1.05 respectively. The maximum DC current of 50 was obtained. A comparison of these results with HBT characteristics obtained using AsH ₃/PH₃ or TBA/PH₃ demonstrates the feasibility of replacing the toxic AsH₃ and PH₃ by less toxic TBA and TBP sources in the growth of GaInP/GaAs HBT's     

Characterization and modeling of bias dependent breakdown and self-heating in GaInP/GaAs power HBT to improve high power amplifier design

It is usual to say that power GaInP/GaAs heterojunction bipolar transistors (HBTs) have many advantages for power amplification at microwave frequencies, because of their high gain and high power density. Furthermore, the possibility of controling the base biasing conditions (voltage, current, self-bias control) compared to a field-effect transistor offers additive degrees of freedom to make a tradeoff between linearity and power-added efficiency. Nevertheless existing devices are limited because of the relatively low breakdown voltage whereas high collector voltage swings are required to achieve high power. This drawback makes them not appropriate for use in the next generation of mobile communication base station or radar systems. Silicon technologies such as LDMOS and III-V devices (MESFET and HFET) present competitive performances in term of high power level but for medium power added efficiency. Important improvements have been made in recent years which make possible large breakdown voltages for GaInP/GaAs HBTs. Breakdown value close to 67 V has been achieved. The aim of this work is to significantly improve the modeling of the breakdown voltage on this type of transistor. Furthermore, the in depth characterization and modeling of self-heating effects have been greatly improved in order to improve thermal management solutions which enable us to enhanced design solutions of HBT high power amplifiers.     

High-gain GaInP/GaAs heterojunction phototransistor utilising guard-ring structure

GaInP/GaAs heterojunction phototransistors with an emitter guard-ring contact are fabricated. The gain and speed of response of a device is significantly improved by the application of bias to the guard-ring, indicating that the recombination current is surface-dominated and that the quality of the GaInP/GaAs heterojunction interface is high.<>     

Application of GaInP/GaAs DHBTs to power amplifiers for wirelesscommunications

Next-generation power amplifiers must operate at lower supply voltages without sacrificing linearity or efficiency. GaInP/GaAs double-heterojunction bipolar transistors with GaInP collectors can improve over GaAs single-heterojunction bipolar transistors (HBTs) in power-amplifier applications, based on lower offset voltage, increased breakdown electric field, and absence of saturation charge storage. To best exploit these characteristics, amplifier architectures that employ HBTs in switching mode can be used     

GaInAsP过渡层在808 nm GaAsP/(Al)GaInP半导体激光器中降电压的应用

利用金属有机化学气相沉积的方法在GaAs衬底上生长了GaInAsP外延层及GaAsP/(Al)GaInP激光器外延层。生长的GaInAsP外延层与GaAs晶格匹配,并且带隙处于Ga_0.5In_0.5P与GaAs中间。在GaInP/GaAs异质结界面插入此结构的GaInAsP过渡层,可以有效的降低异质结的带阶,尤其是价带带阶。相比于突变GaInP/GaAs异质结的808 nm GaAsP/(Al)GaInP半导体激光器,含有GaInAsP过渡层的半导体激光器具有更低的工作电压。因此,在350 mW输出功率下,半导体激光器的功率转换效率由52%提高至60%。并且在大电流注入下,含有GaInAsP过渡层的半导体激光器由于产生的焦耳热减少,具有更高的输出功率。     

Collector/emitter offset voltage in double-heterojunction bipolar transistors

Double-heterojunction bipolar transistors (DHBT) can exhibit a large collector/emitter offset voltage at zero collector current which will adversely affect digital switching circuits. It is shown that this effect results from insufficient grading at the base/collector heterojunction. A GaAlAs/GaAs DHBT grown by MBE having a 130 ? compositional grading at the emitter/base and base/collector junction showed no sign of the collector/emitter offset voltage.     

GaInP/GaAs HBT Sub-Harmonic Gilbert Mixers Using Stacked-LO and Leveled-LO Topologies

This paper discusses and demonstrates the most popular sub-harmonic Gilbert mixers in 2-mum GaInP/GaAs HBT technology. High two local oscillators (2LO)-to-RF isolation is important to alleviate the self-mixing problem of the sub-harmonic mixer. The demonstrated GaInP/GaAs HBT stacked-local oscillator (LO) mixer topology has achieved the best 2LO-to-RF isolation when compared with the previous literature. On the other hand, the leveled-LO sub-harmonic mixers have advantages in terms of the high speed and low dc supply voltage at the cost of much larger LO pumping power. Among all the structures, the bottom-LO sub-harmonic mixer has the lowest current consumption and the simplest circuit structure at the expense of the 2LO-to-RF isolation     

Comparison of GaInP/GaAs heterostructure-emitter bipolartransistors and heterojunction bipolar transistors

Carbon-doped GaInP/GaAs heterojunction bipolar transistors (HBT's) and heterostructure-emitter bipolar transistors (HEBT's) grown by MOCVD were fabricated. Experimental comparison of HBT's and HEBT's has been made based on the dc and the RF performance. HBT's have higher current gains than those of HEBT's in the high current regime, while HEBT's offer a smaller offset voltage and better uniformity in dc characteristics across the wafer. The current gain and cutoff frequency of the DEBT with a 150 Å emitter set-back layer are comparable to those of HBT's. DC (differential) current gains of 600 (900) and 560 (900) were obtained at a collector current density of 2.5×10⁴ A/cm² for the HBT and HEBT, respectively. The cutoff frequencies are 37 and 31 GHz for the HBT and HEBT, respectively. It is shown that there is negligible contribution of the diffusion capacitance to the emitter capacitance in HEBT's with a thin emitter set-back layer but not with a thick emitter set-back layer. The behavior of HEBT's both in dc and RF characteristics is similar to that of HBT's     

高温AlGaInP/GaAs双异质结双极晶体管

利用Mo/W/Ti/Au难熔金属作为发射极欧姆接触设计并制作了一种用于功率放大器的新结构AlGaInP/GaAs双异质结双极晶体管（DHBT），分析了与传统AuGeNi作为接触电极的AlGaInP/GaAs DHBT的直流特性差异．研究结果表明，利用难熔金属作为欧姆接触电极的DHBT器件具有较好的高温特性，并进一步分析了其具有良好高温特性的机理．