In situ resistance measurement during FCVA deposition of ZnO thin films

Abstract

In situ resistance measurement of zinc oxide (ZnO) thin films deposited by filtered cathodic vacuum arc (FCVA) technique was performed using a four/two-point probe method. Large oscillations were observed during ZnO thin films resistance measurements. The resistance dramatically increased during the arc plasma was on, and decreased when the arc plasma was off. During the arc plasma was on, a space charge region of positive and negative plasma ions is gathered on the substrate surface, which acted as a potential energy barrier preventing electrons to move across, hence increasing the resistance measured by the voltmeter. The initial chamber pressure strongly affects the deposition rate of ZnO. A capacitive effect is also observed when four-point probe configuration is adopted. In situ resistance measurements will be useful to monitor deposition processing and also may help to optimize and understand the properties of thin films.