OHMIC CONTACTS TO SEMICONDUCTING DIAMOND USING A TI PT/AU TRILAYER METALLIZATION SCHEME/

Ohmic contacts have been fabricated on a naturally occurring type IIb diamond crystal using an annealed Ti/Pt/Au trilayer metallization wher e the Pt served successfully as a barrier to Ti diffusion into the Au capping layer. However, a specific contact resistance could not be rel iably determined using transmission line model measurements. Auger mic roanalysis revealed the presence of Ti on the diamond surface near the ohmic contact pads. The most likely origin of the Ti on the diamond s urface was determined to be lateral diffusion from beneath the contact pads. This would have produced a nonuniform concentration of Ti acros s the diamond surface which, in turn, would have affected the diamond sheet resistance in a complicated way.