Diamond AFM probe with piezoelectric sensor and actuator

Abstract

In order to develop a diamond AFM probe with a piezoelectric sensor and actuator, we fabricated lead zirconate titanate (PZT) thin film on a diamond thin film substrate and examined its piezoelectric properties. The PZT thin film was sputtered at room temperature and then annealed in a nitrogen (N/sub 2/) ambient to obtain a perovskite structure. On diamond thin film substrates, the value of piezoelectric constant, d/sub 31/, was as low as about -20 pC/N due to rough surface of the diamond film. After a poling treatment, however, its piezoelectric constant improved to about -65 pC/N. For realization of a PZT sensor and actuator on a diamond cantilever, the PZT thin film was also successfully patterned by reactive ion etching (RIE) in SF/sub 6/ plasma using a Pt upper electrode layer as an etching mask without any damage on a diamond layer. Based on the fabrication and patterning of PZT thin film together with microfabrication techniques of CVD diamond film, we demonstrate the diamond AFM probe of 150 /spl mu/m in length, 50 /spl mu/m in width and 5 /spl mu/m in thickness with a PZT sensor and actuator of 1 /spl mu/m in thickness. The resolution of image sensing and actuation force were estimated to be about 0.4 nm at a resolution of charge measurement of 1/spl times/10/sup -15/ C and 12 /spl mu/N at an applied voltage of 8 V, respectively.