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.     

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.     

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。     

太赫兹InP DHBT 器件研究

InP DHBT 器件具有优异的高频特性、良好的散热、击穿和噪声性能,是实现超高频、低噪声功率放大 电路设计的最具性能优势的器件之一。文中简要介绍和分析了影响高频器件电性能参数的主要因素,优化了材料 结构和版图设计,最终采用三台面湿法化学腐蚀工艺、自终止工艺、自对准光刻工艺和空气桥工艺等加工工艺研制 得到发射极线宽0. 7 μm 的InP DHBT 器件,并配套集成了平行板电容和金属薄膜电阻,片内器件一致性良好。不断 缩小器件基区台面面积,器件电性能最终实现:最大直流增益β 为30,10 μA 下的集电极-发射极击穿电压BVCEO 为 3. 2 V,截止频率fT 为358 GHz,最大振荡频率fmax 为407 GHz。测试结果表明,该器件可应用于220 GHz 放大器、 100 GHz 以下压控振荡器等数模混合集成电路。     

共基极与共发射极结构的InP DHBT器件功率特性

制作了发射极面积为1μm×15μm×4指的InP DHBT器件,器件拓扑使用了共基极和共发射极两种结构,通过负载牵引测试系统对器件功率特性进行测试。在功率优化匹配条件下,所测得最大输出功率密度和相应的功率附加效率(PAE)在10GHz下为1.24W/mm和50%,在18GHz下的数据为0.82W/mm和26%。测试同时表明,共发射极结构相对稳定和易于匹配,共基极模式具有更大的输出功率潜力,但需要进一步解决难于匹配、容易振荡和寄生参量影响等问题。在功放电路设计中,可以根据不同需求选择合适的电路拓扑结构。     

InP异质结晶体管

提出了准平面构成的InP HBT新结构，用Si离子注入在半绝缘InP：Fe上形成隐埋n型区来代替通常采用的外延n型收集区，可有效降低器件的高度，减小寄生参数，提高器件的可靠性，测量结果表明，晶体管的hfe=100,VCE=3-4V,fT=10GHz。     

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.     

面向100GHz+数模混合电路的0.5μm InP DHBT工艺

本文报道了一种高性能的3英寸磷化铟双异质结双极型晶体管工艺。发射极尺寸为0.5×5μm2的磷化铟双异质结双极型晶体管,电流增益截止频率以及最高振荡频率分别达到350GHz以及532GHz,击穿电压4.8V。基于该工艺研制了114GHz静态分频器以及170GHz动态分频器两款工艺验证电路,这两款电路的工作频率处于国内领先水平。     

基于InP DHBT工艺的32.2GHz超高速全加器

介绍了一种基于0.7μm磷化铟(InP)双异质结双极型晶体管(DHBT)工艺的超高速全加器,将加法运算与数据同步锁存融合设计来提高计算速度,采用多数决定运算法则设计单层晶体管并联型进位电路来降低功耗。测试结果表明,全加器的最高时钟频率达32.2 GHz,包含锁存器的全加器整体电路功耗为350 mW。     

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.     

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.     

Optimization of the base electrode for InGaAs/InP DHBT structures with a buried emitter-base junction

We have optimized the base electrode for InGaAs/InP based double heterojunction bipolar transistors with a buried emitter-base junction. For the buried emitter-base structure, the base metal is diffused through a thin graded quaternary region, which is doped lightly n-type, to make ohmic contact to the p⁺InGaAs base region. The metal diffusion depth must be controlled, or contact will also be made to the collector region. Several metal schemes were evaluated. An alloy of Pd/Pt/Au was the best choice for the base metal, since it had the lowest contact resistance and a sufficient diffusion depth after annealing. The Pd diffusion depth was easily controlled by limiting the thickness to 50?, and using ample Pt, at least 350?, as a barrier metal to the top layer of Au. Devices with a 500? base region show no degradation in dc characteristics after operation at an emitter current density of 90 kA/cm² and a collector bias, V_CE, of 2V at room temperature for over 500 h. Typical common emitter current gain was 120. An f_t of 95 GHz and f_max, of 131 GHz were achieved for 2×4 μm² emitter size devices.     

Evaluation of encapsulation and passivation of InGaAs/InP DHBT devices for long-term reliability

Device encapsulation and passivation are critical for long-term reliability and stability. Several encapsulation techniques were evaluated in terms of degradation of electrical characteristics, gap filling under the mesa structures, and adhesion to the semiconductor and metal surfaces. These included plasma enhanced chemical vapor deposited (PECVD) SiO₂, electron cyclotron resonance CVD SiN_x, spin-on glass, benzocyclobutene, and polyimide. Damage from plasma exposure caused gain degradation in the devices. Spin-on coatings cause little to no gain degradation, provided that there is minimal stress in the cured film. SOG and BCB films have acceptable adhesion properties and were excellent for gap filling. Polyimide films have excellent adhesion properties, however, they were poor at gap filling and had a great deal of shrinkage during curing. Device passivation was evaluated using double heterojunction bipolar transistor structures with either an abrupt or graded emitter-base junction. Abrupt junction devices had the self-aligned base metal directly on the p⁺ InGaAs base. Graded junction devices had the base metal on top of graded InGaAsP layers, which the metal was diffused through, to make contact to the base region. Abrupt junction devices stressed at an initial J_E of 90 kA/cm² at a V_CE of 2V at 25°C degraded 20% within 70 h of operation, whereas, the graded junction devices show no degradation in dc characteristics after operation for over 500 h. Typical common emitter current gain was 50. An f_t of 80 and f_max of 155 GHz were achieved for 2×4 μm² emitter size devices.     

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.     

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.     

高击穿电压的InGaAs/InP双异质结双极型晶体管

利用台面工艺以及平坦化技术制作了带有复合式集电区的InGaAs/InP双异质结双极型晶体管。所有的工艺都是在3英寸圆片上进行的。发射极面积为1μm15μm的器件,电流增益截止频率为170GHz,最高振荡频率为256GHz,击穿电压为8.3V,这是国内报道的击穿电压最高的InP HBT器件。高的振荡频率以及击穿电压,使得此种类型的器件十分适用于W波段及以上频段压控振荡器（VCO）以及混频器（Mixer）的制作。