Growth of thin SiC films on Si single crystal wafers with a microwave excited plasma of methane gas
Self-limiting SiC film growth on Si
Films of very high quality
We have studied the growth and properties of SiC films on Si wafers, under ultrahigh vacuum background conditions, using a remote-, microwave excited, methane plasma as a source of active carbon and hydrogen, while the Si substrates were held at a temperature of near 700 °C. The reaction is diffusional and should thus be self-limiting, but it actually reaches up to 20–25 nm thickness due to direct transport of Si from the substrate to the top surface through initially open defects in the growing film. These defects gradually fill up during the growth, and the resulting films have a relatively low density of these, and are otherwise very uniform and polycrystalline. They are characterized with scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and hardness measurements.