Published online by Cambridge University Press: 01 February 2011
In this pioneering study, we have extended noble-gas implant-induced cavity generation in Si and other semiconductors to a dielectric, viz., SiO2 by implanting a variety of inert gas species. It has been seen that helium and neon do not induce bubbles/cavities in SiO2, regardless of implantation parameters and nature of the sample. Krypton and xenon implantation however result in bubbles/cavities formation in the oxide layer. In the case of Xe a minimum threshold dose of about 1016 cm-2 is needed for their formation. Characterization by cross-section transmission electron microscopy (XTEM) and Rutherford backscattering spectrometry (RBS) showed that bubbles/cavities remain even after a 1100°C anneal, while Xe strongly desorbs out at that temperature. C-V measurements reveal that the effective dielectric constant K is reduced from 3.9 SiO2 for bulk SiO2 to < 2.6, thus making this technique very attractive for low-k applications in Si technology.