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The obtention of luminescent SiOxCy:H thin films deposited by the HW-CVD technique is reported here. We study the effect of different monomethyl-silane (MMS) flow rates on the films properties. An increase in the emission bandwidth and a red-shift was observed when the MMS flow increased. The luminescence was related to optical transitions in band tail states and with less contribution from quantum confinement effects. After, the films were annealed at 750 °C in nitrogen. The annealed film deposited at the highest MMS flow showed an emission spectrum like the as-deposited film, suggesting the same emission mechanisms. By contrast, the annealed film deposited at the lowest MMS flow showed two emission bands. These bands are due to the activation of radiative defects related to oxygen-deficient centers. MOS-like structures were fabricated as electroluminescent devices using the annealed films. Only the structure of the film with the highest carbon content showed light emission in a broad band in the visible spectrum region in forward bias, with a maximum centered close to 850 nm. The light emission mechanism was related to electron thermalization in the band tail states and a direct hole injection into deep states. The trap-assisted tunneling, Poole–Frenkel emissions and Fowler–Nordheim tunneling were proposed as the charge transport mechanism. [ABSTRACT FROM AUTHOR]

The obtention of luminescent SiOxCy:H thin films deposited by the HW-CVD technique is reported here. We study the effect of different monomethyl-silane (MMS) flow rates on the films properties. An increase in the emission bandwidth and a red-shift was observed when the MMS flow increased. The luminescence was related to optical transitions in band tail states and with less contribution from quantum confinement effects. After, the films were annealed at 750 °C in nitrogen. The annealed film deposited at the highest MMS flow showed an emission spectrum like the as-deposited film, suggesting the same emission mechanisms. By contrast, the annealed film deposited at the lowest MMS flow showed two emission bands. These bands are due to the activation of radiative defects related to oxygen-deficient centers. MOS-like structures were fabricated as electroluminescent devices using the annealed films. Only the structure of the film with the highest carbon content showed light emission in a broad band in the visible spectrum region in forward bias, with a maximum centered close to 850 nm. The light emission mechanism was related to electron thermalization in the band tail states and a direct hole injection into deep states. The trap-assisted tunneling, Poole–Frenkel emissions and Fowler–Nordheim tunneling were proposed as the charge transport mechanism.

Abstract: This paper is devoted to the optical emission studies of Octamethylcyclotetrasiloxane (OMCTS)/O2 derived, low pressure (0.1Torr), 13.56MHz RF plasmas. The emission is recorded with a resolution of 0.05nm to two RF power densities of 0.25 and 0.50W/cm2, at wavelengths of 180–1000nm. Emitting atomic and molecular species in plasma are identified, and spatial variation in emission intensity is recorded through the space between electrodes. The hardness, elastic modulus, infrared absorbance, refractive index, and residual stress of the resulting plasma polymer films are presented. Most of the atomic and molecular emissions have been identified, and spectra can be used as a reference for OMCTS/O2 plasmas. Optical emission spectra are dominated by molecular CO, CO+, OH, and CO2 + bands, and atomic H and O lines. The absence of emissions from the Si, SiO, SiO2, CH, CH2, and CH3, together with the infrared absorbance of films, suggests that SiOxCy:H film formation occurs by way of the dissociation of C–H and Si–C bonds, as well as the polymerization of silica rings or long chains. [ABSTRACT FROM AUTHOR]