The measurement of the thickness of thin SiC layers on silicon

Different measurement techniques as ellipsometry (single wavelength and spectroscopic), AES depth profiling, atomic force microscopy (AFM), infrared absorption and spectroreflectometry were applied for the SiC/Si system and compared with regard to the determined thickness of the grown SiC layer. It was found that the obtained layer thickness including the rough interfaces can be described by an effective layer thickness which represents the volume of the deposited SiC. The surface roughnesses obtained by ellipsometry and AES depth profiling correspond to typical description parameters determined by AFM. It is shown that in contrary to some published opinions the ellipsometry is well suitable for a reliable thickness measurement of thin SiC layers on Si in spite of the surface and interface roughness.