Development of Low Resistance Al/Ti Stacked Metal Contacts to p-Type 4H-SiC

Abstract

In this work, we have investigated triple and innovative multiple stacked contacts onto ptype SiC in order to evaluate whether or not there is any improvement in morphology or specific contact resistivity. The stacked metal contacts are based on Al, Ti and Ni with the specific contact resistivity measured at a low value of 5.02×10-6'cm2 for an Al(100 nm)/Ti(100 nm)/Al(10 nm) (where a “/” indicates the deposition sequence) triple stacked metal contact. XRD microstructural analysis and SEM measurements have been carried out and it has been discovered that the contacts, which formed the compound Ti3SiC2 at the metal/SiC interface, more readily display low-resistance ohmic characteristics after a post deposition anneal. Although the same amount of Ti (100 nm in total) has been deposited closer to the metal/SiC interface, none of the multiple stacked structures displayed ohmic behaviour after a post deposition anneal.