A SiC metallization scheme using an ALD protective layer for harsh environment devices

This paper reports on the development of a silicon carbide (SiC) metallization scheme, capable of surviving high temperatures (450°C) in air for an extended time (>;100h). The interfacial reactions between the SiC and the metal contact are mitigated via a carbon diffusion barrier and the whole metallization is protected with a thin alumina layer deposited by atomic layer deposition (ALD) to prevent oxygen penetration and degradation of the carbon barrier layer. A demonstrated lifetime in excess of 100h at 450°C in air is presented and the contact interface is carefully characterized.