No abstract

No abstract

The reduction of surface "native" oxides from GaAs substrates following reactions with trimethylaluminum ͑TMA͒ precursor is studied using medium energy ion scattering spectroscopy ͑MEIS͒ and x-ray photoelectron spectroscopy ͑XPS͒. MEIS measurements after one single TMA pulse show that ϳ65% of the native oxide is reduced, confirmed by XPS measurement, and a 5 Å thick oxygen-rich aluminum oxide layer is formed. This reduction occurs upon TMA exposure to as-received GaAs wafers.

We report a systematic study of the bias stress effect at semiconductor-dielectric interfaces using singlecrystal organic field-effect transistors as a test bed. A combination of electrical transport and ultraviolet photoelectron spectroscopy suggests that this instability is due to a ground-state ͑i.e., occurring in the dark͒ charge transfer of holes from the accumulation channel of the semiconductor to localized states of a disordered insulator. The proposed model is not semiconductor specific and therefore provides a general analytical description of this instability in a variety of organic and inorganic band semiconductors interfaced with amorphous insulators.

We have developed and used for the first time a soft x-ray interferometer to probe a large laserproduced plasma with micron spatial resolutions.A neonlike yttrium x-ray laser operating at 155 A was combined with a multilayer coated Mach-Zehnder interferometer to obtain electron density profiles in a plasma produced by laser irradiation of a CH target. The measured electron density profile has been compared to hydrodynamic simulations and shows good agreement near the ablation surface but some discrepancy exists at lower densities.