The use of 3D simulations is essential in order to study the effects of fluctuations when devices are scaled to deep submicron dimensions. A 3D drift-diffusion device simulator has been developed to effectively simulate pseudomorphic high electron mobility transistors (pHEMTs) on a distributed memory multiprocessor computer. The drift-diffusion equations are discretized using a finite element m...

As an extension of our previous works in the optical-microwave interaction field, this paper shows the result of the research on large signal dynamic behavior (Pulsed I/V curves) of AlGaAs P-HEMT (pseudomorphic high electron mobility transistor) devices, in the overall I/V plane, when the incident optical input power is changed. A complete bias and optical power dependent of the large signal mo...

Scanning thermal microscopy has been implemented in a cross-sectional geometry, and its application for quantitative, nanoscale analysis of thermal conductivity is demonstrated in studies of an ErAs/GaAs nanocomposite superlattice. Spurious measurement effects, attributable to local thermal transport through air, were observed near large step edges, but could be eliminated by thermocompression ...

Terahertz radiation was generated with several designs of photoconductive antennas (three dipoles, a bow tie, and a coplanar strip line) fabricated on low-temperature-grown (LT) GaAs and semi-insulating (SI) GaAs, and the emission properties of the photoconductive antennas were compared with each other. The radiation spectrum of each antenna was characterized with the photoconductive sampling t...

The InAs/InGaAs dots-in-a-well (DWELL) structures were grown on both GaAs(311) B and (100) substrates by molecular beam epitaxy. Quantum dots (QDs) grown on GaAs(311) B substrate are of higher density and more uniform size distribution, yet QDs grown on GaAs(100) substrate demonstrate a bimodal size distribution. The growth mechanism of these surface morphologies was briefly discussed. We found...

The polarization of photoemitted electrons from thin GaAs layers grown by molecular beam epitaxy(MBE) h as 1 ,een measured. Pola,riza.tion as high as 49% was observed for a 0.2 pm thick GaAs sample at excitation photon wavelengths longer than 750 nm. The maximum polarization is dependent on the thickness of the GaAs layer, decreasing to about 41% for-a 0.9 pm thick GaAs sample. ‘*

A tribochemistry-assisted method has been developed for nondestructive surface nanofabrication on GaAs. Without any applied electric field and post etching, hollow nanostructures can be directly fabricated on GaAs surfaces by sliding a SiO2 microsphere under an ultralow contact pressure in humid air. TEM observation on the cross-section of the fabricated area shows that there is no appreciable ...

The current–voltage (I–V) and capacitance–voltage (C–V) characteristics of Au/n-GaAs Schottky diodes on n-Ge substrates are investigated and compared with characteristics of diodes on GaAs substrates. The diodes show the non-ideal behavior of I–V characteristics with an ideality factor of 1.13 and barrier height of 0.735 eV. The forward bias saturation current was found to be large (3×10 A vs. ...