Triple implant (In,Ga)As/InP n-p-n heterojunction bipolar transistors for integrated circuit applications

For the first time (In,Ga)As/InP n-p-n heterojunction bipolar transistors (HJBT's) applicable to integrated circuits have been fabricated by triple ion implantation. The base has been formed by beryllium ion implantation and the collector by silicon ion implantation. The implants were made into an LPE-grown n-n (In,Ga)As/InP heterostructure on an n+-InP substrate. This inverted mode emitter-down heterojunction transistor structure demonstrates to a maximum current gain of 7 with no hysteresis in the characteristics. The ideality factors of the IBversus VBE, and ICversus VBEcharacterisitics with VCB= 0, are 1.25 and 1.08, respectively, indicating that the defect level in the herterojunction is low and that minority-carrier injection and diffusion is the dominant current flow mechanism.     

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.     

High-gain In0.53Ga0.47As:Fe photoconductive detectors

Photoconductive detectors were fabricated on semi-insulating liquid phase epitaxial In0.53Ga0.47As/InP doped with Fe for the first time. Their performance characteristics have been compared with identical devices made from Zn-doped p-In0.53Ga0.47As/InP. Internal optical gains up to 10 were measured in the Fe-doped devices. The bias and intensity-dependent gain characteristics of these devices are discussed.     

HBT结构的新进展

介绍了以In0.03Ga0.97As0.99N0.01材料为基区的GaAs异质结双极型晶体管和以GaAs0.51Sb0.49材料为基区的InP HBT.讨论了GaAs和InP HBT结构的新进展及其对性能的改善,并对各结构的适用范围和优缺点进行了比较.     

Temperature dependence of breakdown and avalanche multiplication in In/sub 0.53/Ga/sub 0.47/As diodes and heterojunction bipolar transistors

The avalanche multiplication and impact ionization coefficients in In/sub 0.53/Ga/sub 0.47/As p-i-n and n-i-p diodes over a range of temperature from 20-400 K were measured and shown to have negative temperature dependence. This is contrary to the positive temperature dependence of the breakdown voltage measured on InP/In/sub 0.53/Ga/sub 0.47/As heterojunction bipolar transistors (HBTs) in this and previous works. It is shown that the collector-base dark current and current gain can be the overriding influence on the temperature dependence of breakdown in InP/In/sub 0.53/Ga/sub 0.47/As HBTs and could explain previous anomalous interpretations from the latter.     

Pseudomorphic AlInP/InP heterojunction bipolar transistors

Novel InP-based heterojunction bipolar transistors (HBTs) using an AlInP pseudomorphic emitter, together with an InP base and collector, have been fabricated. By using InP as both base and collector, the advantage of high electron velocity and high breakdown field of InP collectors are obtained without the problem associated with the energy barrier between the more standard InGaAs/InP base and collector heterojunction. Epitaxial layers were grown by gas-source molecular beam epitaxy (GSMBE). The 200 Å pseudomorphic emitter had an aluminium fraction of 15%, sufficiently suppressing hole injection from the base. The DC gain for 40×40 μm² devices reached 18. The breakdown voltage BV_CEO of 10 V is an improvement over devices with InGaAs base and collector layers     

0.5 mu m gate length InP/In/sub 0.75/Ga/sub 0.25/As/InP pseudomorphic HEMT with high DC and RF performance

High performance InP/In/sub 0.75/Ga/sub 0.25/As/InP pseudomorphic double heterojunction (DH) HEMTs with a gate length of 0.5 mu m are reported. Both DC and RF characteristics of this new type of Al-free HEMT demonstrate its suitability for microwave applications.<>     

High-performance InP/InGaAs heterojunction bipolar transistors with highly carbon-doped base grown by chemical beam epitaxy

InP/In/sub 0.53/Ga/sub 0.47/As heterojunction bipolar transistors (HBTs) using a highly carbon-doped base are reported. High carbon doping has been achieved by chemical beam epitaxy (CBE). The resulting hole concentration in the carbon-doped base is as high as 7*10/sup 19//cm/sup 3/. To the authors' knowledge, this is the highest doping level reported using carbon. HBTs with a 20 AA spacer layer exhibited nearly ideal I-V characteristics with collector and base current ideality factor of 1.018 and 1.037, respectively. Current gain and breakdown voltage BV/sub CEO/ were 7 and 6 V, respectively.<>     

22 nm In0.75Ga0.25As channel-based HEMTs on InP/GaAs substrates for future THz applications

In this work, the performance of L_g=22 nm In_0.75Ga_0.25As channel-based high electron mobility transistor (HEMT) on InP substrate is compared with metamorphic high electron mobility transistor (MHEMT) on GaAs substrate. The devices features heavily doped In_0.6Ga_0.4As source/drain (S/D) regions, Si double δ-doping planar sheets on either side of the In_0.75Ga_0.25As channel layer to enhance the transconductance, and buried Pt metal gate technology for reducing short channel effects. The TCAD simulation results show that the InP HEMT performance is superior to GaAs MHEMT in terms of f_T, f_max and transconductance (g_{m_max}). The 22 nm InP HEMT shows an f_T of 733 GHz and an f_max of 1340 GHz where as in GaAs MHEMT it is 644 GHz and 924 GHz, respectively. InGaAs channel-based HEMTs on InP/GaAs substrates are suitable for future sub-millimeter and millimeter wave applications.     

Collector-pedestal InGaAs/InP DHBTs fabricated in a single-growth, triple-implant process

This letter reports InP/In/sub 0.53/Ga/sub 0.47/As/InP double heterojunction bipolar transistors (DHBTs) employing an N/sup +/ subcollector and N/sup +/ collector pedestal-formed by blanket Fe and patterned Si ion implants, intended to reduce the extrinsic collector-base capacitance C/sub cb/ associated with the device footprint. The Fe implant is used to compensate Si within the upper 130 nm of the N/sup +/ subcollector that lies underneath the base ohmic contact, as well as compensate the /spl sim/1-7/spl times/10/sup -7/ C/cm/sup 2/ surface charge at the interface between the indium phosphide (InP) substrate and the N/sup $/collector drift layer. By implanting the subcollector, C/sub cb/ associated with the base interconnect pad is eliminated, and when combined with the Fe implant and selective Si pedestal implant, further reduces C/sub cb/ by creating a thick extrinsic collector region underneath the base contact. Unlike previous InP heterojunction bipolar transistor collector pedestal processes, multiple epitaxial growths are not required. The InP DHBTs here have simultaneous 352-GHz f/sub /spl tau// and 403-GHz f/sub max/. The dc current gain /spl beta//spl ap/38, BV/sub ceo/=6.0 V, BV/sub cbo/=5.4 V, and I/sub cbo/<50 pA at V/sub cb/=0.3 V.     

InGaAs/InP DHBTs with 120-nm collector having simultaneously high f/sub /spl tau//, f/sub max//spl ges/450 GHz

InP/In/sub 0.53/Ga/sub 0.47/As/InP double heterojunction bipolar transistors (DHBT) have been designed for increased bandwidth digital and analog circuits, and fabricated using a conventional mesa structure. These devices exhibit a maximum 450 GHz f/sub /spl tau// and 490 GHz f/sub max/, which is the highest simultaneous f/sub /spl tau// and f/sub max/ for any HBT. The devices have been scaled vertically for reduced electron collector transit time and aggressively scaled laterally to minimize the base-collector capacitance associated with thinner collectors. The dc current gain /spl beta/ is /spl ap/ 40 and V/sub BR,CEO/=3.9 V. The devices operate up to 25 mW//spl mu/m/sup 2/ dissipation (failing at J/sub e/=10 mA//spl mu/m/sup 2/, V/sub ce/=2.5 V, /spl Delta/T/sub failure/=301 K) and there is no evidence of current blocking up to J/sub e//spl ges/12 mA//spl mu/m/sup 2/ at V/sub ce/=2.0 V from the base-collector grade. The devices reported here employ a 30-nm highly doped InGaAs base, and a 120-nm collector containing an InGaAs/InAlAs superlattice grade at the base-collector junction.     

High-gain Al0.48In0.52As/Ga0.53As vertical n-p-n heterojunction bipolar transistors grown by molecular-beam epitaxy

We report the first vertical n-p-n heterojunction bipolar transistors formed in the (Al,In)As/(Ga,In)As alloy system. The structures grown by molecular-beam epitaxy (MBE) use a wide band-gap (Eg = 1.44 eV) Al0.48In0.52As emitter on a lower band gap (Eg = 0.73 eV) Ga0.47In0.53As base 2500 Å in width. Transistors with both abrupt and graded heterojunction emitters were demonstrated with dc current gains of 140 and 280, respectively, at a collector current of 15 mA. The (Al,In)As/(Ga,In)As heterojunction transistors offer the attractive possibility of optical integration with long wavelength lasers and photodetectors.     

High-performance In/sub 0.53/Ga/sub 0.47/As thermophotovoltaic devices grown by solid source molecular beam epitaxy

In/sub 0.53/Ga/sub 0.47/As-based monolithic interconnected modules (MIMs) of thermophotovoltaic (TPV) devices lattice-matched to InP were grown by solid source molecular beam epitaxy. The MIM device consisted of ten individual In/sub 0.53/Ga/sub 0.47/As TPV cells connected in series on an InP substrate. An open-circuit voltage (V/sub oc/) of 4.82 V, short-circuit current density (J/sub sc/) of 1.03 A/cm/sup 2/ and fill factor of /spl sim/73% were achieved for a ten-junction MIM with a bandgap of 0.74 eV under high intensity white light illumination. Device performance uniformity was better than 1.5% across a full 2-in InP wafer. The V/sub oc/ and J/sub sc/ values are the highest yet reported for 0.74-eV band gap n-p-n MIM devices.     

Effects of arsenic mole fraction x on the gain characteristics of type-II InP/GaAsxSb1−x DHBTs

The static gain characteristics of N–p–N InP/GaAs_xSb_1?x/InP double heterojunction bipolar transistors (DHBTs) were studied as a function of the base arsenic (As) mole fraction x. Compared to the devices with a lattice-matched base (x = 0.51), a current gain improvement largely arising from a base current reduction is observed in DHBTs with higher As base mole fractions (and consequently a reduced type-II conduction band discontinuity ΔE_C at the emitter-base heterojunction). Both the surface periphery and the intrinsic recombination currents decrease markedly as the base arsenic concentration increases. The present work therefore unambiguously demonstrates that the emitter type-II conduction band discontinuity between the InP emitter and the GaAs_xSb_1?x base enhances the undesirable emitter size effects (ESEs) and increases intrinsic recombination currents directly under the emitter contact.     

MESFET-like transferred-electron devices in In/sub 0.53/Ga/sub 0.47/As

In/sub 0.53/Ga/sub 0.47/As transferred-electron devices with Schottky-gate electrodes were fabricated. These devices can be used in optoelectronic circuits on InP or as millimetre wave oscillators. For the realisation of the gate electrode several enhancement layers were tested to increase the Schottky barrier height on In/sub 0.53/Ga/sub 0.47/As. The triggering of single dipole domains in the device was demonstrated.<>     

纳米电子器件-高峰值峰谷电流比InP基共振隧穿二极管的实现

利用分子束外延技术研制出InP基IhAs/In0.53Ga0.47As/AlAs共振隧穿二极管,其中势垒为10个单分子AlAs,势阱由8个单分子层In0.53Ga0.47As阱和4个单分子层InAs子阱组成.室温下峰值电流密度接近3kA/cm2,峰和谷的电流密度比率达到19.     

InP衬底上Ga_(0.47)In_(0.53)As/InP液相外延生长

用液相外廷获得了与InP晶格匹配的Ga_(0.47),In_(0.53)As单晶外延层.本文叙述在(100)和(111)InP衬底上Ga_(0.47)In_(0.53)As/InP液相外延生长方法.用常规滑动舟工艺生长的这种外延层,其表面光亮,Ga的组分x=0.46～0.48,晶格失配率小于2.77×10~(-4),禁带宽度E_g=0.74～0.75eV.使用这种Ga_(0.47)In_(0.53)As/InP/InP(衬底)材料研制的长波长光电探测器,在波长为0.9～1.7μm范围内测出了光谱响应曲线,在1.55μm处呈现峰值.     

(GaAl)As/GaAs heterojunction bipolar transistors with graded composition in the base

The first fabrication and high-speed operation of a three-terminal (AlGa)As/GaAs heterojunction bipolar transistor with graded bandgap base is reported. Cutoff frequencies up to 16 GHz have been achieved in devices fabricated from material made by molecular beam epitaxy. This work demonstrates the feasibility of using a graded (AlGa)As base to enhance the speed of heterojunction bipolar transistors.     

Avalanche noise characteristics of single Al/sub x/Ga/sub 1-x/As(0.3

Groves  C. Chia  C.K. Tozer  R.C. David  J.P.R. Rees  G.J. 《Quantum Electronics, IEEE Journal of》2005,41(1):70-75

Heterojunction bipolar transistor using a (Ga,In)P emitter on a GaAs base, grown by molecular beam epitaxy

We report the first N-p-n heterojunction bipolar transistor (HBT) using a (Ga,In)P/GaAs heterojunction emitter on a GaAs base. This combination is of interest as a potential alternate to (Al,Ga)As/GaAs, because of theoretical predictions of a larger valence band discontinuity and a smaller conduction band discontinuity, thus eliminating the need for grading of the emitter/base junction. The structure was grown by molecular beam epitaxy, with the base doping (∼10¹⁹cm^-3) far exceeding the n-type doping ∼5¹⁷cm^-3) of the (Ga,In)P wide gap emitter (Eg= 1.88 eV). Common-emitter current gains of 30 were attained at a current density of 3000 A/cm², the highest current density achieved without burnout.