UV-laser-assisted processing of thin silicon–germanium–carbon films

Abstract

The aim of enhancing the performance of solar cells and microelectronic devices through band-gap engineering as well as the demand of using cheap organic substrates or advanced materials like “high- k dielectrics” for nanoelectronic based technologies has caused an increasing attention in alternative processes for growing thin silicon–germanium–carbon alloys. Laser-induced chemical vapour deposition (LCVD), excimer laser-assisted crystallisation (ELC) and pulsed laser-induced epitaxy (PLIE) are such alternative techniques that are relatively cheap and capable to provide films in a wide range of composition and crystalline structure. This contribution shows some typical results achieved combining these laser-assisted techniques, thus demonstrating the potential of integrated laser-assisted “single-chamber” processes. The growth of amorphous hydrogenated SiGeC coatings at 250 °C with, on nanometer-scale, well-tailored thickness on large area as well as on small selected areas using LCVD is presented and discussed. The subsequent irradiation of these films in a single-chamber process for the dehydrogenation of the amorphous material, the modification of these coatings to polycrystalline or nanocrystalline films via ELC or to heteroepitaxial alloys on Si(100) wafers through PLIE, is also shown and evaluated. The selected samples that will be shown have been extensively studied through Fourier transform infrared and X-ray photoelectron spectroscopy, time of flight secondary ion mass spectrometry, Rutherford backscattering, X-ray diffraction, atomic force microscopy and scanning electron as well as conventional and high-resolution transmission electron microscopy.