R. N. Nottenburg

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/sub

Hot-electron InGaAs/InP heterostructure bipolar transistors with f/sub T/ of 110 GHz

/T=165 GHz and maximum oscillation frequency f/sub MAX/=100 GHz at room temperature. The authors model shows that an f/sub

Ultrahigh Be doping of Ga0.47In0.53As by low‐temperature molecular beam epitaxy

/T beyond 386 GHz is obtainable by further vertical scaling. Ring oscillators implemented with nonthreshold logic (NTL) and transistors having f/sub MAX/=71 GHz show a propagation delay of 14.7 ps and 5.4 mW average power consumption per stage.<<ETX>>

High-current-gain submicrometer InGaAs/InP heterostructure bipolar transistors

A hot-electron InGaAs/InP heterostructure bipolar transistor (HBT) is discussed. A unity-current-gain cutoff frequency of 110 GHz and a maximum frequency of oscillation of 58 GHz are realized in transistors with 3.2*3.2- mu m/sup 2/ emitter size. Nonequilibrium electron transport, with an average electron velocity approaching 4*10/sup 7/ cm/s through the thin (650 AA) heavily doped (p=5*10/sup 19/ cm/sup -3/) InGaAs base and 3000-AA-wide collector space-charge region, results in a transit delay of 0.5 ps corresponding to an intrinsic cutoff frequency of 318 GHz.<<ETX>>

Near‐ideal lateral scaling in abrupt Al0.48In0.52As/In0.53Ga0.47As heterostructure bipolar transistors prepared by molecular beam epitaxy

Layers of Ga0.47In0.53As grown on InP by a beam epitaxy method have been doped with Be to p=5×1020 cm−3 by growth at substrate temperatures as low as 365 °C. The maximum doping level is strongly growth temperature dependent. Heterostructure bipolar transistors with base doping p=1×1020 cm−3, current gain β=54, and unity current gain cutoff frequency fT=140 GHz are illustrated.

Microwave noise performance of InP/InGaAs heterostructure bipolar transistors

Common-emitter current gains of 115 and 170 are achieved in transistors with emitter dimensions as small as 0.3*3 and 0.8*3 mu m/sup 2/, respectively. These results are comparable with scaling experiments reported for Si bipolar devices and represent a significant improvement over AlGaAs/GaAs heterostructure bipolar transistors. Both the low surface recombination velocity and nonequilibrium carrier transport in the thin (800-AA) InGaAs base enhance the DC performance of these transistors.<<ETX>>

Dynamic and static response of multielectrode lasers

We demonstrate near‐ideal lateral scaling in abrupt junction Al0.48In0.52As /In0.53Ga0.47As heterostructure bipolar transistors. Current gain β=162 and 122 has been realized in transistors with emitter stripe width of 50 and 0.6 μm, respectively. The excellent lateral scaling occurs because the 0.5 eV emitter injection energy results in nonequilibrium vertical electron transport in the thin (700 A) InGaAs base.

Base doping limits in heterostructure bipolar transistors

The authors report the first low-noise InP/InGaAs heterostructure bipolar transistor (HBT). Minimum noise figures of 0.46, 2.0, and 3.33 dB were measured at 2, 10, and 18 GHz, respectively. The noise performance of this InP/InGaAs HBT with an emitter size of 3.5*3.5 mu m/sup 2/ is compared to that for FETs having a 1- mu m gate length. The measured minimum noise figures agree well with calculated data using a modified Hawkins model. Broadband low-noise operation is observed because of the short transit time for injected nonequilibrium electrons to transverse the base and collector depletion region.<<ETX>>

Influence of base thickness on collector breakdown in abrupt AlInAs/InGaAs heterostructure bipolar transistors

We compare the measured and calculated light output of a semiconductor laser modulated by a saturable intracavity absorber. An accurate description of the dynamic and static behavior requires inclusion of both a carrier concentration dependent recombination rate and a voltage‐dependent saturable absorption.

Multielectrode quantum well laser for digital switching

Heterostructure bipolar transistors are used to experimentally determine band offsets in lattice‐matched In0.53Ga0.47As devices. Valence‐band offsets of ΔEV=0.24 eV for Al0.48In0.52As/In0.53Ga0.47As and ΔEV=0.34 eV for InP/In0.53Ga0.47As are measured. Because of band filling in the base, these values place important constraints on p‐type doping levels and emitter injection efficiency in practical devices.