REMOTE OXYGEN-CONTAINING HYDROGEN PLASMA TREATMENT OF POROUS SILICON

The effects of treatment with remote oxygen-containing hydrogen plasma on electrochemically etched porous silicon have been studied. X-ray p hotoelectron spectroscopy, infrared, and elastic recoil detection meas urements showed the nonuniform incorporation of oxygen in the porous s ilicon layer. The amount of nitrogen increased while the carbon concen tration dropped in the oxidized layer. The photoluminiscence (PL) inte nsity of plasma-treated films increased by up to a factor of approxima tely 70 compared to as-prepared samples, while the peak position was r ed shifted. The PL enhancement seems to be correlated with an O/Si rat io near 1.5. After treatment, bright PL was observed from a partially oxidized layer, covered by a SiO2 layer which could be several nm thic k.