Ta-O-N thin films deposited by low vacuum reactive sputtering

Ta-O-N films deposited by sputtering have stable electrical resistances. They have been used in microelectronics and thin-film resistors. It has been also reported that they exhibit high thermal stability, diffusion barrier function, wear resistance and oxidation resistance. In this study, we attempted to observe the composition change. The soda glass substrate or (100) silicon wafer was used as substrate. The 99.95% purity tantalum target was used. The base pressure was 2.5 Pa. Argon and nitrogen gas purity were six-nine grades. Nitrogen gas flow rate was varied for change the films composition. For the film deposited in 9% nitrogen gas ratio, the film had like fcc-TaN structure by XRD. Lattice constant along the film surface were larger than the value of the card date. At the film deposited in 9% nitrogen gas flow ratio, about 47% tantalum, 43% nitrogen and 10% oxygen element were included by the ZAF measurement of EPMA. For the film deposited in about 17% nitrogen gas flow ratio, 32% tantalum, 57% nitrogen and 11% oxygen element were detected. Ta-O and Ta-N binding energy were measured by XPS.