Contact characterizations of ZrN thin films obtained by reactive sputtering

The contact properties of ZrN on p-type Si obtained by magnetron reactive sputtering were investigated. Schottky diodes characteristics were evaluated by current-voltage (I-V) and capacitance voltage (C-V) measurements. The barrier heights obtained by I-V and C-V are in the range of 0.55-0.63V and 0.88-0.91V, respectively. Due to the possible presence of interfacial layer and interface states which are located at the ZrN-semiconductor interface the I-V curves are not ideal. It is likely that n, the ideality factor is controlled by the interface state density. For each diode investigated in the ZrN/Si system, the barrier heights measured by the C-V method are considerably higher than those evaluated by I-V technique. At this stage we cannot present a theoretical explanation for the difference between the values of φ_Bp beyond the speculations that the presence of interface states might be responsible for the difference. Since I-V measurements tend to emphasize the lower value of φ_Bp while C-V measurements would give a value of φ_Bp averaged over the entire interface the more probable magnitude of the barrier height can be assumed to be those measured by I-V technique.