Base-collector leakage currents in InP/InGaAs double heterojunctionbipolar transistors

For InP/InGaAs HBT's, base-collector leakage current can restrict their operation to a narrow emitter-collector voltage range. We studied several factors that can degrade the leakage current: the base-collector junction design, the base mesa etching technique, and the base metallization process. A step-graded base-collector heterojunction offered the best results. A leakage free multiple step etching process, combining wet and dry etching, has been developed. Ti/Pt/Au is a suitable base metallization, provided that the platinum layer is not too thick, and that the contact annealing temperature is not too high. Finally, very low leakage current HBT's were fabricated     

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     

High-speed, high-current-gain p-n-p InP/InGaAs heterojunctionbipolar transistors

p-n-p InP/InGaAs heterojunction bipolar transistors (HBTs) are reported for the first time. The transistors, grown by metal organic molecular beam epitaxy (MOMBE), exhibited maximum DC current gain values up to 420 for a base doping level of 4×10¹⁸ cm^-3 . Small-signal measurements on self-aligned transistors with 3-μm×8-μm emitter area indicated the unity gain cutoff frequency value of 10.5 GHz and the inferred maximum frequency of oscillation of 25 GHz. The results clearly demonstrate the feasibility of complementary integrated circuits in the InP material system     

InGaAs/InP composite collector heterostructure bipolar transistors

A high speed bipolar transistor with high breakdown voltage BV/sub CEO/ is described. The structure uses a composite collector of InGaAs and InP. A common emitter gain of 65 is obtained with a base doping of 7*10/sup 19/ cm/sup -3/ and a breakdown voltage in excess of 10 V. The f/sub T/=64 GHz was reached at a collector-emitter voltage of 2 V and a current density of 52 kA/cm/sup 2/. The potential of this structure for very high speed applications is demonstrated by the extracted intrinsic transit time of 0.4 ps.<>     

Co-integration of resonant tunneling and double heterojunctionbipolar transistors on InP

The authors report the first co-integration of resonant tunneling and heterojunction bipolar transistors. Both transistors are produced from a single epitaxial growth by metalorganic molecular beam epitaxy, on InP substrates. The fabrication process yields 9-μm²-emitter resonant tunneling bipolar transistors (RTBTs) operating at room temperature with peak-to-valley current ratios (PVRs) in the common-emitter transistor configuration, exceeding 70, at a resonant peak current density of 10 kA/cm², and a differential current gain at resonance of 19. The breakdown voltage of the In_0.53Ga_0.47As-InP base/collector junction, V_CBO, is 4.2 V, which is sufficient for logic function demonstrations. Co-integrated 9-μm²-emitter double heterojunction bipolar transistors (DHBTs) with low collector/emitter offset voltage, 200 mV, and DC current gain as high as 32 are also obtained. On-wafer S-parameter measurements of the current gain cutoff frequency (f_T) and the maximum frequency of oscillation (f_max) yielded f _T and f_max values of 11 and 21 GHz for the RTBT and 59 and 43 GHz for the HBT, respectively     

Avalanche InP/InGaAs heterojunction phototransistor

We report on the characteristics of an avalanche InP/InGaAs heterojunction phototransistor. Below the turnover voltage, the gain is bias dependent and avalanching can be used to achieve significant (sim5times) improvement in the gain-bandwidth product. The noise current in this bias region has been measured and is shown to be predominantly shot noise of the photocurrent and the leakage current. Above the turnover voltage, negative resistance is observed and extremely high gains (>10⁴) are achieved. In this mode, the pulse response is a narrow spike (rise time ≃ 20 ns) whose width is independent of the width of the incident optical pulse.     

InP/InGaAs double heterostructure bipolar transistors grown by MBE

Double heterostructure bipolar transistors have been fabricated on InP/InGaAs MBE material. Current gains of up to 80 have been observed in the emitter-up configuration. The devices were fabricated using two diffusion techniques and selective etching to contact the base.     

InGaAs/InP红外雪崩光电探测器的研究现状与进展

近年来,量子卫星通信、主动成像等先进技术的应用取得了较大的进展,InGaAs/InP雪崩光电探测器作为信息接收端的核心器件起到了至关重要的作用.本文系统介绍了InGaAs/InP雪崩光电探测器的工作原理,分析了器件结构设计对暗电流特性的影响,对盖格模式下多种单光子探测电路进行了综述,同时对新型金属-绝缘体-金属结构设计的研究进展进行了介绍和展望.     

10Gbit/s InGaAs/InP雪崩光电二极管

基于InGaAs/InP吸收区、渐变区、电荷区和倍增区分离雪崩光电二极管(SAGCMAPD)器件结构,利用数值计算方法,模拟了各层参数对器件频率响应特性的影响.模拟结果表明,吸收层、倍增层厚度及电荷层面电荷密度可影响器件的-3 dB带宽;随增益的增加,器件带宽会逐渐降低;电荷层面电荷密度对器件击穿电压有明显影响.结合此模拟结果,制作出了高速InGaAs/InP雪崩光电二极管,并对器件进行了封装测试.测试结果表明,该结果与模拟结果相吻合.器件击穿电压为30 V;在倍增因子为1时,器件响应度大于0.8 A/W;在倍增因子为9时,器件暗电流小于10 nA,-3 dB带宽大于10 GHz,其性能满足10 Gbit/s光纤通信应用要求.     

High-speed InP/InGaAs heterojunction bipolar transistors

Very-high-performance common-emitter InP/InGaAs single heterojunction bipolar transistors (HBTs) grown by metalorganic molecular beam epitaxy (MOMBE) are reported. They exhibit a maximum oscillation frequency (f_T) of 180 GHz at a current density of 1×10⁵ A/cm². this corresponds to an (R_BC_BC)_eff=f _T/(8πf²_max) delay time of 0.12 ps, which is the smallest value every reported for common-emitter InP/InGaAs HBTs. The devices have 11 μm² total emitter area and exhibit current gain values up to 100 at zero base-collector bias voltage. The breakdown voltage of these devices is high with measured BV_CEO and BV_CEO of 8 and 17 V, respectively     

Ultra-high-speed InP/InGaAs heterojunction bipolar transistors

We report on the microwave performance of InP/In_0.53Ga _0.47As heterojunction bipolar transistors (HBT's) utilizing a carbon-doped base grown by chemical beam epitaxy (CBE). The f_T and f_max of the HBT having two 1.5×10 μm² emitter fingers were 175 GHz and 70 GHz, respectively, at I_C=40 mA and V_CE=1.5 V. To our knowledge, the f _T of this device is the highest of any type of bipolar transistors yet reported. These results indicate the great potential of carbon-doped base InP/InGaAs HBT's for high-speed applications     

Subpicosecond InP/InGaAs heterostructure bipolar transistors

Bipolar transistors with subpicosecond extrinsic delay are discussed. These InP/InGaAs heterostructure transistors show a unity-current-gain cutoff frequency f_$T=165 GHz and maximum oscillation frequency f_MAX=100 GHz at room temperature. The authors model shows that an f_$T beyond 386 GHz is obtainable by further vertical scaling. Ring oscillators implemented with nonthreshold logic (NTL) and transistors having f_MAX=71 GHz show a propagation delay of 14.7 ps and 5.4 mW average power consumption per stage     

Selfaligned InGaAs/InP heterostructure bipolar transistors

InGaAs/InP heterostructure bipolar transistors have been realised using a new selfaligned process. Transistor wafers were grown by chemical beam epitaxy. Ideality factors close to unity were measured for emitter-base and collector-base diodes. The resulting devices exhibit nearly constant gain over four orders of magnitude of collector current densities, from j=1.5*10/sup -4/ A/cm/sup 2/ to 1.5 A/cm/sup 2/.<>     

平面型InP/InGaAs雪崩光电二极管多级台阶结构研究

平面型雪崩光电二极管(APD)在结弯曲处具有更高的电场,易导致结边缘的提前击穿.运用FEMLAB软件对多级台阶结构的平面型InP/lnGaAs APD的电场分布进行了二维有限元模拟,在表面电荷密度为5×10~(11)cm~(-2)时分析了台阶级数、台阶高度等因素对边缘提前击穿特性的抑制程度.通过理论研究对平面InP/InGaAS APD进行了优化.

Abstract：

For planar-type avalanche photodiode (APD), it is hard to suppress edge pre-breakdown with double-stepped p-region profile. In order to suppress the edge pre-breakdown, amulti-stepped p-region is proposed and studied. A finite element two-dimensional (2-D) simulation is performed to study the electric field of planar-type APD with multi-stepped p-region. The effects of the step number and deep in suppressing the edge pre-breakdown are analyzed and the planar-type APD structure is optimized theoretically.     

Avalanche buildup time of InP/InGaAsP/InGaAs avalanche photodiodes with separate absorption, grading, and multiplication regions

The avalanche buildup time of an avalanche photodiode can be determined from the frequency response of the noise power as a function of the dc multiplication M0. In this paper we report on the first measurements of the avalanche buildup time of InP/InGaAsP/ InGaAs avalanche photodiodes with separate absorption, grading, and multiplication regions (SAGM-APD's). Measurements on several different device structures reveal that the avalanche buildup time (gain-bandwidth product) decreases (increases) with increasing carrier concentration in the multiplication region. The shortest buildup time that we have observed wasM_{0} times 4.2ps which corresponds to a gain-bandwidth Product of 38 GHz.     

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.     

Be diffusion in InGaAs/InP heterojunction bipolar transistors

Classic signatures of Be diffusion were observed in InAlAs/InGaAs HBT's after elevated temperature bias stress, i.e., a positive shift in the Gummel plot, higher collector ideality, and higher offset voltage. An activation energy of 1.57 eV was calculated. Lifetimes of 3.3×106 h and 37000 h were extrapolated for low and high power operation, respectively. In contrast, an InP/InGaAs HBT with a C doped base showed no signatures of C diffusion. The results show that Be diffusion is manageable at lower power. They also support the idea that C is more stable than Be in this material system     

Comparative study of InP/InGaAs double heterojunction bipolar transistors with InGaAsP spacer at base-collector junction

In this article, the influence of InGaAsP spacers inserted at base-collector (B-C) junction in the InP/In_0.53Ga_0.47As double heterojunction bipolar transistors is demonstrated by two-dimensional semiconductor simulation. Due to the addition of an InGaAsP spacer layer, two small potential spikes are formed at B-C junction and the current blocking effect is reduced. The results exhibit that the maximum current gain increases from 30 to 374 (375) as the thickness of InGaAsP spacer layer varies from 0 to 100 Å (300 Å). On the other hand, the device with a thicker spacer layer (300 Å) could effectively improve the knee effect of the current-voltage curves as compared the other devices. In addition, the collector-emitter offset voltages less than 10 mV are observed in the three devices.     

InGaAs/InP盖革模式雪崩焦平面阵列的研制

设计制作了一种由InGaAs/InP雪崩光电二极管阵列与时间计数型CMOS读出电路组成的8×8阵列规格盖革模式雪崩焦平面阵列(GM APD FPA).雪崩光电二极管采用SAGCM结构,在盖革模式下工作具有单光子探测灵敏度;时间计数型CMOS读出电路在每个单元获取光子飞行时间,实现纳秒级的时间分辨率,并完成雪崩淬灭功能.测试结果表明,倒装混合集成的GM APD FPA器件暗计数率(DCR)均值为32.5 kHz,单光子探测效率(PDE)均值为19.5％,单元时间抖动为465 ps,实现了光脉冲时间信息的探测,验证了盖革模式雪崩焦平面阵列技术及其在三维成像中应用的可行性.     

InGaAs/InP heterobipolar transistors for integration on semi-insulating InP substrates

InGaAs/InP npn heterojunction bipolar transistors (HBTs) have been fabricated from LPE layers grown on semi-insulating InP substrates for application to integrated circuits. The inverted emitter configuration is used, which allows the growth of the active layers without any additional steps. The HBTs show stable characteristics without any hysteresis and with current gains up to 25 for 0.7 ?m base width. To our knowledge this is the first report of InGaAs/InP HBTs on a semi-insulating substrate.