Mechanical properties of deposited carbon thin films on sapphire substrates using atomic force microscopy (AFM)

Abstract

In this study, the mechanical properties of nano-layered carbon thin films deposited on Al2O3 single crystal substrates with varying orientations in A (1120), M (1010), R (1102) and C (0001) planes were investigated using depth-sensing nanoindentation techniques. All of the nano-layered films were deposited by a thermionic vacuum arc (TVA). In this experiment, a high purity amorphous carbon rod was used. Single crystal Al2O3 plates were used as the substrate material. All of the substrates were a commercial product that is readily available. For the surface topography, the roughness and depth-sensing nano-hardness of the deposited films were analyzed using an Ambios Q-scope atomic force microscope. An F20 thin film measurement system was used for the determination of thickness and reflection properties of the deposited thin films. Indention depths were determined as 5nm, 10nm and 15nm. In these indentation depths, hardness values were calculated in the range of 8–25GPa.