Overview of recent development of HEMTs in the mm-wave range

Takamiya, S.; Yoshida, N.; Hayafuji, N.; Sonoda, T.; Mitsui, S.

doi:10.1016/0038-1101(95)00066-3

Cited by 27 publications

(4 citation statements)

References 24 publications

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“…To grow pseudomorphic strained layers, the critical thickness at which the strain in a lattice mismatched layer relaxes through the generation of misfit dislocation must be known. 8,9 An improvement over the GaAs/InGaAs PHEMT is the AlGaAs/InGaAs PHEMT with a small AlAs mole fraction, [10][11][12] which has a larger conduction-band discontinuity than the GaAs/InGaAs PHEMT, supporting a greater carrier concentration without experiencing the effects related to a large mole fraction of AlGaAs. Although excellent performance has been achieved by growing pseudomorphic strained channel layers on GaAs substrates, the In mole fraction, x, used in such devices is limited to around 0.25.…”

mentioning

confidence: 99%

Effects of Selective and Nonselective Wet Gate Recess on InAlAs∕InGaAs Metamorphic Field-Effect Transistors with Double Delta Doping in InGaAs Channels

Lin

2011

J. Electrochem. Soc.

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This investigation reports on the first symmetrically double-delta-doped channel InAlAs/InGaAs/GaAs metamorphic field-effect transistor ͑MFET͒. Two types of devices are fabricated as follows. In the fabrication of the first, the gate recessing steps are carried out using nonselective etching solution ͑phosphoric acid/hydrogen peroxide mixtures͒. In the fabrication of the second, a pH 5.5 selective succinic acid:ammonia hydrogen peroxide:water wet chemical etching liquid is adopted to form the gate recess. A succinic acid-based solution is found to be a better selective etchant of an InGaAs/InAlAs system than the more commonly used phosphoric acid-based solutions, in terms of the etching selectivity and the smoothness of the etched surface. The etch-stop mechanism is inferred from Auger electron spectroscopy to involve the formation of nonvolatile aluminum oxide, in strong agreement with the X-ray photoelectron spectroscopy spectra. Nearly kink-free current-voltage characteristics are achieved. The assessment of these structures for application in power field-effect transistor devices reveals that high frequency, high transconductance devices are feasible. As far as the authors are aware, this study is the first to compare MFETs that use a nonselective wet gate recess with those that use a selective wet gate recess.The speedily widening market for wireless communication devices in the past has increased the need for GaAs-based epitaxial materials. 1-3 Field-effect transistors ͑FETs͒ are important in today's high frequency communication systems. 4 The development of high electron mobility transistors ͑HEMTs͒ in the late 1970s in the AlGaAs/GaAs materials system gave device designers the opportunity to exploit the high mobility of undoped GaAs to improve fieldeffect transistor performance. The primary motivation for the use of the AlGaAs/GaAs system is that AlGaAs is lattice-matched to GaAs over the entire compositional range. 5,6 The GaAs/InGaAs pseudomorphic high electron mobility transistor ͑PHEMT͒ has attracted interest as an alternative to the AlGaAs/GaAs HEMTs because it exhibits excellent carrier confinement and a depressed deep-level concentration in the material with the higher bandgap, which results in persistent photoconductivity at cryogenic temperatures. 7 Most importantly, InGaAs layers on GaAs substrates have been popular for use in PHEMTs because they have favorable transport over GaAs, substrates of which are relatively cost-effective. To grow pseudomorphic strained layers, the critical thickness at which the strain in a lattice mismatched layer relaxes through the generation of misfit dislocation must be known. 8,9 An improvement over the GaAs/InGaAs PHEMT is the AlGaAs/InGaAs PHEMT with a small AlAs mole fraction, 10-12 which has a larger conduction-band discontinuity than the GaAs/InGaAs PHEMT, supporting a greater carrier concentration without experiencing the effects related to a large mole fraction of AlGaAs. Although excellent performance has been achieved by growing pseudomorphic strained ch...

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mentioning

confidence: 99%

Effects of Selective and Nonselective Wet Gate Recess on InAlAs∕InGaAs Metamorphic Field-Effect Transistors with Double Delta Doping in InGaAs Channels

Lin

2011

J. Electrochem. Soc.

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“…AlGaAs/InGaAs/GaAs pseudomorphic high electron mobility transistors (P-HEMTs) have demonstrated tremendous potential in high power microwave and millimeter wave devices and for several RF front end applications including phased array radar, satellite communication, wireless LAN, cellular phone, etc [1,2]. They exhibit superior power gain and low noise characteristics at higher frequencies.…”

Section: Introductionmentioning

confidence: 99%

Observation of indium segregation effects in structural and optical properties of pseudomorphic HEMT structures

Mishra¹,

Ramesh²,

Srinivasan³

et al. 2005

Semicond. Sci. Technol.

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We present a detailed study on the influence of several growth related factors such as indium segregation, spacer layer thickness and Si δ doping on the structural, optical and electrical properties of molecular beam epitaxy grown pseudomorphic high electron mobility transistor (P-HEMT) structures. Simulation of a high resolution x-ray diffraction (HRXRD) rocking curve was performed and compared with the experimental data to determine the quantum well (QW) thickness and composition as well as the indium segregation related changes in the QW composition. It is shown that growth of a thin layer (6 Å) of GaAs on top of the pseudomorphic InGaAs layer followed by 'flash-off' at a higher temperature could minimize the indium segregation related degradation of the hetero interface. Photoluminescence (PL) and surface photo voltage (SPV) peaks corresponding to the sub-band transitions are analysed using a self-consistent solution of Schrödinger and Poisson equations. PL results showed the dependence of the transition energies on the spacer layer thickness and the effectiveness of the carrier transfer into the InGaAs well. SPV spectra showed characteristic peaks from all the layers in the HEMT structures and were correlated with the data obtained from PL and HRXRD.

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“…Recently there has been considerable interest in pseudomorphic high electron mobility transistor (pHEMT) owing to their performance in low-noise, high-power microwave and high-speed digital applications [1,2]. This kind of device usually consists of an undoped quantum well structure and one or more n-type doped barrier layers.…”

Section: Introductionmentioning

confidence: 99%

Room-temperature phototransmittance and photoluminescence characterization of the AlGaAs/InGaAs/GaAs pseudomorphic high electron mobility transistor structures with varied quantum well compositional profiles

Lin

Huang

Tiong

et al. 1999

Semicond. Sci. Technol.

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We have studied the effects of the two-dimensional electron gas (2DEG) and indium surface segregation in four pseudomorphic AlGaAs/InGaAs/GaAs high electron mobility transistor structures using room-temperature phototransmittance (PT) and photoluminescence (PL) measurements. The PT spectra from the InGaAs modulation-doped quantum well channel can be accounted for by a lineshape function which is the first-derivative of a step-like two-dimensional density of states and a Fermi level filling factor. A detailed lineshape fit makes it possible to evaluate the Fermi energy, and hence the concentration of 2DEG in addition to the energies of the intersubband transitions. The lowest-lying intersubband transition has been confirmed by a comparison of the PT and PL spectra. From the difference of intersubband transition energies, the surface segregation effects of indium atoms are demonstrated.

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Overview of recent development of HEMTs in the mm-wave range

Cited by 27 publications

References 24 publications

Effects of Selective and Nonselective Wet Gate Recess on InAlAs∕InGaAs Metamorphic Field-Effect Transistors with Double Delta Doping in InGaAs Channels

Effects of Selective and Nonselective Wet Gate Recess on InAlAs∕InGaAs Metamorphic Field-Effect Transistors with Double Delta Doping in InGaAs Channels

Observation of indium segregation effects in structural and optical properties of pseudomorphic HEMT structures

Room-temperature phototransmittance and photoluminescence characterization of the AlGaAs/InGaAs/GaAs pseudomorphic high electron mobility transistor structures with varied quantum well compositional profiles

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