AlGaAs/InGaAs/GaAs quantum-well power MISFET at millimeter-wave frequencies

We report on the fabrication and characterization of quantum-doped graded-like channel heterojunction field-effect transistors (HFETs) by molecular beam epitaxy (MBE) using a multiple pulse doping technique. The extended equations describing the piecewise doping profiles have been developed to derive the transconductance and second-harmonic to fundamental ratio. It is found that the thickness of depletion width dominates the maximum transconductance and the high doping gradient offers the device linearity. Two HFETs with different doping gradients have been fabricated to elucidate this concept. We obtain the maximum extrinsic transconductance of 165 mS mm −1 . Both have broad plateaus on their transconductance versus gate-to-source voltage profiles. Further, the devices exhibit a gate-to-drain and a drain-to-source breakdown voltage larger than 25 V. The very small output conductance and good pinch-off characteristics indicate good confinement of the electrons in a quantum-doped channel.

Section: Introductionmentioning

confidence: 99%

Low-distortion AlGaAs/InGaAs power HFETs with quantum-doped graded-like channels

Lour

Chen

Hung

1997

“…Doped-channel field-effect transistors (DCFETs) have demonstrated great performance in device linearity, current drive and breakdown voltage [1][2][3][4][5].…”

Section: Introductionmentioning

confidence: 99%

“…Generally, the DCFET could match many key figures of merit of the PHEMT while avoiding several of its inherent drawbacks [1][2][3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Direct current and alternating current performance in InGaP/GaAs FETs using airbridge gate with multiple piers

Chen¹,

Wu²,

Lour³

et al. 1999

This paper reports dc and ac performance in airbridge-gate InGaP/In x Ga 1−x As doped channel field-effect transistors (DCFETs). The key features are (1) very high doping density in a V-shape-like quantum channel and (2) an airbridge gate with multiple piers. The measured peak carrier concentration and sheet carrier density are 1.0 × 10 19 cm −3 and 7.2 × 10 12 cm −2 with an electron mobility of 3660 cm 2 V −1 s −1 at room temperature. Both airbridge-gate and mesa-gate DCFETs were fabricated on the same wafer. The former has its gate-feeder directly lie on multiple piers while the latter has part of the gate feeder come to rest upon the mesa ramps. In the case of dc performance investigation, we find that the gate feeder upon the mesa ramp strongly affects behaviours of the Schottky contact. Additional leakage current, induced barrier lowering, reduced breakdown voltage and temperature-dependent characteristics were observed for mesa-gate DCFETs. For a 1 × 100 µm 2 airbridge-gate (mesa-type) DCFET, the measured output current at V GS = 0.0 V and the maximum transconductance are 660 (520) mA mm −1 , and 260 (220) mS mm −1 , respectively. In case of ac performance measurement, the airbridge-gate and mesa-type FETs exhibit f t of 17 and 14 GHz and f max of 32 and 28 GHz, respectively.

“…Heterostructure field-effect transistors (HFETs) are of great interest for high-power and ultra-high-frequency microwave circuit applications. Both high electron mobility transistors (HEMTs) [1][2][3] and metal-insulator-semiconductor fieldeffect transistors (MISFETs) [4][5][6] have shown excellent device performances. Unfortunately, the fabrication of these HFETs by conventional mesa isolation results in mesasidewall effect.…”

Section: Introductionmentioning

confidence: 99%

Influences of the mesa-sidewall effect on Ga_0.51In_0.49P/In_0.15Ga_0.85As pseudomorphic transistors

Chang

Pan

Wang

et al. 1999

The influences of the mesa-sidewall effect on dc and RF performances of Ga 0.51 In 0.49 P/In 0.15 Ga 0.85 As pseudomorphic high electron mobility transistors are studied and demonstrated. The leakage current path and parasitic capacitance induced from mesa-sidewalls seriously affect the device characteristics, including the excessive gate leakage current, the reduced breakdown voltage, the degraded RF current gain frequency and the increased sidegating effect.