RESUMO
Al2O3 (5 nm)/Si (bulk) sample was subjected to irradiation of 5 keV electrons at room temperature, in a vacuum chamber (pressure 1 × 10-9 mbar) and formation of amorphous SiO2 around the interface was observed. The oxygen for the silicon dioxide growth was provided by the electron bombardment induced bond breaking in Al2O3 and the subsequent production of neutral and/or charged oxygen. The amorphous SiO2 rich layer has grown into the Al2O3 layer showing that oxygen as well as silicon transport occurred during irradiation at room temperature. We propose that both transports are mediated by local electric field and charged and/or uncharged defects created by the electron irradiation. The direct modification of metal oxide/silicon interface by electron-beam irradiation is a promising method of accomplishing direct write electron-beam lithography at buried interfaces.
RESUMO
A Gires-Tournois interferometer has been applied for intracavity chirp compensation of an actively mode-locked GaAs laser. Fourier-transform-limited pulses as short as 4.6 psec have been obtained at 790 nm.
RESUMO
Reactive sputtering of silicon nitride was used to prepare single layer antireflection coating on one of the facets of a semiconductor laser. During the deposition the film thickness was controlled with two different methods. In the first case the laser was driven below its threshold current, and the light emitted from the facet being coated controlled the thickness. In the second case the lasing mode was used and the light from the rear facet of the laser was directed to the detector via an interference filter and used to monitor the decay of the lasing light. The residual reflectivity achieved was 10(-4).