Atom-probe Study of Metal-SiC Interfaces

Good quality field ion images of sup 2 H-SiC and Beta-SiC whisker were obtained using a He imaging gas at 20K. The compositional depth profiles of annealed specimens of SiC showed that the surface region was enriched in C and that the top layer consisted of carbon atoms only. In contrary, the Si concentration at the surface was found to increase when annealed in the presence of 0z or H sub 2 O gas. In our present study on the Ti/SiC system, we conclude; (1) SiC was Ti did not mix with SiC at all below room temperature, in contrast to the case of the Ti/Si system. (2) Annealing at higher temperatures (equivalent 700 degrees C) resulted in intermixing of Ti, Si and C at the interface. The thickness of the interface was estimated to be approximately three atomic layers. In the Pd/SiC system, intermixing at the interface was noticed after annealing at lower temperature than the Ti/SiC system.