NEW-TYPE OF SCHOTTKY BARRIERS USING NITI SHAPE-MEMORY ALLOY-FILMS

With the aim of studying the feasibility of sensors using NiTi shape m emory alloy films, we have realised NiTi/Si(n)/Si(n(+)) structures by sputter depositing NiTi contacts on Si substrates. The NiTi sputtering was performed at low substrate temperature (423 K) to avoid the forma tion of a silicide interfacial layer, Current-voltage (I(V)) measureme nts on these structures show a rectifying behaviour. The barrier heigh t and ideality factor were determined from these measurements. The inf luence of the martensitic phase transformation in the NiTi electrode o n the electrical properties of the diodes was investigated by recordin g the I(V) characteristics at various temperatures. This study shows a n unusual current decrease with increasing temperature above 353 K. Th e mechanisms responsible for this phenomenon are discussed.