基于InP衬底的GaAsSb/InP异质结晶体管

采用金属有机化学气相沉积生长了InP/GaAs0.5Sb0.5/InP 双异质结晶体三极管(DHBT)材料,研究了材料质量对器件性能的影响.制备的器件不但具有非常好的直流特性,而且还表现出良好的微波特性,其结果与能带理论的预言一致,DHBT集电结和发射结的电流理想因子分别为1.00和1.06,击穿电压高达15V,电流放大增益截止频率超过100GHz.     

带有复合掺杂层集电区的InP/InGaAs/InP DHBT直流特性分析

设计了一种新结构InP/InGaAs/InP双异质结双极晶体管(DHBT),在集电区与基区之间插入n+-InP层,以降低集电结的导带势垒尖峰,克服电流阻挡效应.采用基于热场发射和连续性方程的发射透射模型,计算了n+-InP插入层掺杂浓度和厚度对InP/InGaAs/InP DHBT集电结导带有效势垒高度和I-V特性的影响.结果表明,当n+-InP插入层掺杂浓度为3×1019cm-3、厚度为3nm时,可以获得较好的器件特性.采用气态源分子束外延(GSMBE)技术成功地生长出InP/InGaAs/InP DHBT结构材料.器件研制结果表明,所设计的DHBT材料结构能有效降低集电结的导带势垒尖峰,显著改善器件的输出特性.     

带有复合掺杂层集电区的InP/InGaAs/InP DHBT直流特性分析

设计了一种新结构InP/InGaAs/InP双异质结双极晶体管(DHBT),在集电区与基区之间插入n -InP层,以降低集电结的导带势垒尖峰,克服电流阻挡效应.采用基于热场发射和连续性方程的发射透射模型,计算了n -InP插入层掺杂浓度和厚度对InP/InGaAs/InP DHBT集电结导带有效势垒高度和I-V特性的影响.结果表明,当n -InP插入层掺杂浓度为3×1019cm-3、厚度为3nm时,可以获得较好的器件特性.采用气态源分子束外延(GSMBE)技术成功地生长出InP/InGaAs/InP DHBT结构材料.器件研制结果表明,所设计的DHBT材料结构能有效降低集电结的导带势垒尖峰,显著改善器件的输出特性.     

InP/InGaAs/InP双异质结双极晶体管技术研究

介绍了InP/InGaAs/InP双异质结双极晶体管(DHBT)材料生长、器件结构与设计、制作工艺和性能测试以及在振荡器中的应用等方面的研究.采用发射极-基极自对准工艺制作了InP/InGaAs/InP DHBT器件,发射极尺寸为1.5μm×10μm的器件小电流直流增益β约25,集电极-发射极击穿电压BVCEO≥10V,截止频率,ft和最高振荡频率,fmax分别为50和55GHz;     

InP/InGaAs/InP双异质结双极晶体管技术研究

介绍了InP/InGaAs/InP双异质结双极晶体管(DHBT)材料生长、器件结构与设计、制作工艺和性能测试以及在振荡器中的应用等方面的研究.采用发射极-基极自对准工艺制作了InP/InGaAs/InP DHBT器件,发射极尺寸为1.5μm×10μm的器件小电流直流增益β约25,集电极-发射极击穿电压BVCEO≥10V,截止频率,ft和最高振荡频率,fmax分别为50和55GHz;     

InP/GaAsSb/InP双异质结双极晶体管技术发展现状(Ⅰ)

InP/GaAsSb/InP双异质结双极晶体管(DHBT)以其独特的交错Ⅱ型能带结构,在频率特性、击穿特性和热特性等方面较传统的InP/InGaAsSHBT与InP/InGaAs/InPDHBT等显示出极大的优越性。对InP/GaAsSb/InPⅡ型DHBT技术的提出、外延层结构设计与生长、器件结构设计、器件制造工艺与优化以及国内外发展情况研究水平、发展趋势和商业化情况进行了系统的回顾和展望。指出结合垂直方向材料结构优化缩小器件尺寸和采用微空气桥隔离基极电极结构是InP/GaAsSb/InPDHBT向THz截止频率发展的最重要的技术路线。     

InP DHBT技术的最新进展

阐述了目前InP DHBT器件技术的研究进展,介绍了I型InP/InGaAs DHBT技术的研究水平和Ⅱ型InP/GaAsSb DHBT技术的开发现状。综述了InP DHBT在功率放大器、分布放大器、静态分频器和压控振荡器领域的应用,指出了其在高速数据传输系统中的重要性。为了适应高速数据传输系统的飞速发展,满足10/40/100Gbit/s高速系统的技术需求,对我国研发InPDHBT技术提出初步建议。     

InP DHBT技术的最新进展

阐述了目前InP DHBT器件技术的研究进展,介绍了I型InP/InGaAs DHBT技术的研究水平和Ⅱ型InP/GaAsSb DHBT技术的开发现状。综述了InP DHBT在功率放大器、分布放大器、静态分频器和压控振荡器领域的应用,指出了其在高速数据传输系统中的重要性。为了适应高速数据传输系统的飞速发展,满足10/40/100Gbit/s高速系统的技术需求,对我国研发InPDHBT技术提出初步建议。     

fT=140GHz,fmax=200GHz的超高速InP DHBT

InP/InGaAs/InP DHBT具有频带宽、电流驱动能力强、线性好、相位噪声低和阈值电压一致性好等优点成为研究热点。通过优化外延材料结构设计和采用四元InGaAsP缓变层消除集电结电流阻塞效应;改进发射极-基极自对准工艺和集电区台面侧向腐蚀工艺,降低Rb和Cbc乘积;优化PI钝化工艺和空气桥互联等工艺,实现了发射极面积为2μm×10μm的自对准InP/InGaAs/InP DHBT器件,其直流增益β约为25,击穿电压BVCEO≥7 V@10μA,在VCE=4 V,Ic=10 mA下,截止频率fT=140 GHz,最高振荡频率fmax=200 GHz,优于同一外延片上的非自对准InP DHB器件,该器件将可应用于高速光通信和微波毫米波通信。     

带有阶梯缓变集电区的InP/InGaAs/InP DHBT材料研究

设计并生长了一种新的InP/InGaAs/InP DHBT结构材料,采用在基区和集电区之间插入两层不同禁带宽度的InGaAsP四元系材料的阶梯缓变集电结结构,以解决InP/InGaAs/InP 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,获得了高质量的InP、InGaAs以及与InP晶格相匹配的不同禁带宽度的InGaAsP外延材料。在此基础上,成功地生长出带有阶梯缓变集电区结构的InP基DHBT结构材料。     

InP/GaAsSb/InP double HBTs: a new alternative for InP-based DHBTs

We report on the physical operation and performance of MOCVD-grown abrupt heterojunction InP/GaAs_0.51Sb_0.49/InP double heterojunction bipolar transistors (DHBTs). In particular, the effect of the InP collector thickness on the breakdown voltage and on the current gain cutoff frequency is assessed and a f_T of 106 GHz is reported for a DHBT with a 400 Å base and a 2000 Å InP collector with a BV_CEO of 8 V. We show that InP/GaAsSb/InP DHBTs are characterized by a weak variation of f_T as a function of temperature. Finally, we also demonstrate that high maximum oscillation frequencies f_MAX>f_T can be achieved in scaled high-speed InP/GaAsSb/InP DHBTs, and provide estimates of the maximum cutoff frequencies achievable for this emergent but promising material system. Recent results on improved structures validate our performance predictions with cutoff frequencies well beyond 200 GHz     

Metamorphic Heterostructure InP/GaAsSb/InP HBTs on GaAs Substrates by MOCVD

Good-quality metamorphic InP buffer layers have been successfully grown on GaAs substrates by metal-organic chemical vapor deposition. Characterization by atomic force microscope, transmission electron microscopy, high-resolution X-ray diffraction, and Hall measurements indicated that the layers are of high crystalline quality, good mobility, and excellent surface morphology. On this buffer, we demonstrated the first metamorphic InP/GaAsSb/InP double heterojunction bipolar transistors (DHBTs) with good material quality and device performance. Metamorphic DHBTs showed direct-current and radio-frequency characteristics that are comparable to those grown on lattice-matched InP substrates.     

High-Current-Gain InP/GaInP/GaAsSb/InP DHBTs With fT = 436 GHz

Combining a pseudomorphically strained (Ga,In)P emitter with a GaAs_0.6Sb_0.4 base effectively eliminates the emitter heterojunction type-II conduction band offset in InP/GaAsSb double heterojunction bipolar transistors (DHBTs). A peak f_T of 436 GHz at J_C = 10 mA/mum², with BV_CEO = 3.8 V, is achieved with 0.6 times 5 mum² InP/GalnP/GaAsSb DHBTs with a 75-nm InP collector. Compared to a binary InP emitter, the (Ga,In)P emitter doubles the DC current gain from 166 to 338 for otherwise identical devices. These are the highest DC current gain and cutoff frequencies to date in uniform base GaAsSb DHBTs. The gain improvement reported here will greatly facilitate device design tradeoffs that are encountered while scaling InP/GaAsSb DHBTs toward higher frequencies by allowing higher base doping levels and smaller emitter geometries.     

10-GHz power performance of a type II InP/GaAsSb DHBT

Type-II InP/GaAsSb double heterojunction bipolar transistors (DHBTs) were fabricated and microwave power performance was measured. For an InP collector thickness of 150 nm, the DHBTs show a current gain of 24, low offset voltages, and a BV/sub CEO/>6V. The 1.2/spl times/16 /spl mu/m/sup 2/ devices show f/sub T/=205GHz and f/sub MAX/=106GHz at J/sub C/=304 kA/cm/sup 2/. These devices delivered 12.6 dBm to the load at P/sub AVS/=3.3 dBm operating at 10 GHz, yielding a power-added efficiency of 41% and G/sub T/=9.3 dB.     

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.     

300 GHz InP/GaAsSb/InP double HBTs with high current capability andBVCEO>6 V

We report MOCVD-grown NpN InP/GaAsSb/InP abrupt double heterojunction bipolar transistors (DHBTs) with simultaneous values of f _T and f_MAX as high as 300 GHz for J_C=410 kA/cm² at V_CE=1.8 V. The devices maintain outstanding dynamic performances over a wide range of biases including the saturation mode. In this material system the p+ GaAsSb base conduction band edge lies 0.10-0.15 eV above the InP collector conduction band, thus favoring the use of nongraded base-collector designs without the current blocking effect found in conventional InP/GaInAs-based DHBTs. The 2000 Å InP collector provides good breakdown voltages of BV_CEO=6 V and a small collector signal delay of ~0.23 ps. Thinner 1500 Å collectors allow operation at still higher currents with f_T>200 GHz at J_C=650 kA/cm²     

High breakdown voltage InGaAs/InP double heterojunction bipolar transistors with fmax=256 GHz and BVCEO= 8.3 V

正An InGaAs/InP DHBT with an InGaAsP composite collector is designed and fabricated using triple mesa structural and planarization technology.All processes are on 3-inch wafers.The DHBT with an emitter area of 1 x 15μm~2 exhibits a current cutoff frequency f_t = 170 GHz and a maximum oscillation frequency f_(max) = 256 GHz.The breakdown voltage is 8.3 V,which is to our knowledge the highest BV_(CEO) ever reported for InGaAs/InP DHBTs in China with comparable high frequency performances.The high speed InGaAs/InP DHBTs with high breakdown voltage are promising for voltage-controlled oscillator and mixer applications at W band or even higher frequencies.     

Ultra high-speed InP/InGaAs DHBTs with ft of 203 GHz

InP/InGaAs/InP double heterojunction bipolar transistors (DHBTs) were designed for wide band digital and analog circuits, and fabricated using a conventional mesa structure with benzocyclobutene (BCB) passivation and planarization process techniques. Our devices exhibit a maximum ft of 203 GHz, which is the highest ft for DHBTs in mainland China. The emitter size is 1.0×20 μm2. The DC current gain β is 166, and BVCEO=4.34 V. The devices reported here employ a 40 nm highly doped InGaAs base region and a 203 nm InGaAsP composite structure. They are suitable for high speed and intermediate power applications.