Effects on the Surface and Luminescence Properties of GaAs by SF6 Plasma Passivation

Abstract

The passivation effects of the SF6 plasma on a GaAs surface has been investigated by using the radio frequency (RF) plasma method. The RF’s power, chamber pressure, and plasma treatment time are optimized by photoluminescence (PL), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The PL intensity of passivated GaAs samples is about 1.8 times higher than those which are untreated. The oxide traps and As-As dimers can be removed effectively by using SF6 plasma treatment, and Ga-F can form on the surface of GaAs. It has also been found that the stability of the passivated GaAs surface can be enhanced by depositing SiO2 films onto the GaAs surface. These indicate that the passivation of GaAs surfaces can be achieved by using SF6 plasma treatment.

Widely Tunable Angular Non-Critical Phase-Matching Wavelengths from 0.72 to 1.42 μm Based on RE1xRE21−xCOB Mixed Crystals

“…Currently, the availability of laser frequencies in visible spectral ranges are mainly via three ways. One is semiconductor lasers which directly produce visible lights [4,5], another is Pr 3+ , Tb 3+ , Sm 3+ or Dy 3+ ions doped laser crystals pumped by semiconductor lasers [6][7][8], the last one is frequency doubling of near-infrared lasers by nonlinear optical (NLO) crystals [9][10][11]. Using frequency doubling of lasers operating in the near-infrared ranges was the most efficient means to obtain visible lights, which usually contained two ways of phase-matching (PM) methods, i.e., critical phase-matching (CPM) and angular non-critical phase-matching (A-NCPM).…”