Douglas C. Hall

High-power, near-diffraction-limited large-area traveling-wave semiconductor amplifiers

Operating characteristics of high-power large-active-area GaAlAs amplifiers configured in double-pass and single-pass traveling-wave arrangements are described. Single-pass broad-area amplifiers with a 600- mu m stripe width generated up to 21 W of near-diffraction-limited emission under pulsed operation when injected with 500 mW from a Ti:Al/sub 2/O/sub 3/ laser, and 11.6 W when injected with 100 mW from a laser diode master laser. In CW operation, a broad-area amplifier output of 3.3 W was demonstrated. Tapered-stripe large-area amplifiers emitted up to 4.5 W in a near-diffraction-limited beam when injected with 150 mW from a Ti:Al/sub 2/O/sub 3/ laser. The physical mechanisms causing degradation of the output beam phase front and intensity uniformity at high output power levels, including thermal lensing and filamentation, are presented. >

GaAs MOSFET using InAlP native oxide as gate dielectric

GaAs metal-oxide-semiconductor field-effect transistors (MOSFETs) using wet thermally oxidized InAlP as the gate insulator are reported for the first time. Leakage current measurements show that the 11-nm-thick native oxide grown from an In/sub 0.49/Al/sub 0.51/P layer lattice-matched to GaAs has good insulating properties, with a measured leakage current density of 1.39/spl times/10/sup -7/ mA//spl mu/m/sup 2/ at 1 V bias. GaAs MOSFETs with InAlP native gate oxide have been fabricated with gate lengths from 7 to 2 /spl mu/m. Devices with 2-/spl mu/m-long gates exhibit a peak extrinsic transconductance of 24.2 mS/mm, an intrinsic transconductance of 63.8 mS/mm, a threshold voltage of 0.15 V, and an off-state gate-drain breakdown voltage of 21.2 V. Numerical Poissons equation solutions provide close agreement with the measured sheet resistance and threshold voltage.

Nonselective Wet Oxidation of AlGaAs Heterostructure Waveguides Through Controlled Addition of Oxygen

We present data showing that the addition of trace amounts of O<tex>

Microwave performance of GaAs MOSFET with wet thermally oxidized InAlP gate dielectric

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Electrical properties of InAlP native oxides for metal–oxide–semiconductor device applications

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Effect of dislocation scattering on the transport properties of InN grown on GaN substrates by molecular beam epitaxy

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Room-temperature 1.5 μm photoluminescence of Er3+-doped AlxGa1−xAs native oxides

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Fabrication and Performance of 0.25-

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m Gate Length Depletion-Mode GaAs-Channel MOSFETs With Self-Aligned InAlP Native Oxide Gate Dielectric

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