Ultraviolet Light Irradiation Effects on Silicon Doping of GaAs Grown by the Triethylgallium-Arsine OMVPE Method

Publisher Website
Google Scholar
Abstract
The silicon doping of low-pressure OMVPE GaAs has been studied using disilane (Si2H6) as a doping source. Triethylgallium (TEG) and arsine (AsH3) are used as starting materials. A 240–300 nm ultraviolet (UV) light irradiation has been found to enhance silicon doping, though the UV light wavelengths are longer than the absorption edge (200 nm) of Si2H6. The doping enhancement increases with a decrease in the substrate temperature below 700°C. The temperature dependence of the doping enhancement strongly differs from that for the case using trimethylgallium (TMG). From quadrupole mass spectrometer (QMS) analysis of gases in the reactor, it has been found that the doping enhancement corresponds closely to the amount of reaction products, (C2H5) n SiH4-n (n=1–3). A doping enhancement mechanism, including radical generation, is discussed.