Effect of sputtering target power density on topography and residual stress during growth of nanocomposite nc-TiN/a-SiNx thin films

Zhang, Sam, Sun, Deen, Fu, Yong Qing, Du, Hejun and Zhang, Qing (2004) Effect of sputtering target power density on topography and residual stress during growth of nanocomposite nc-TiN/a-SiNx thin films. Diamond and Related Materials, 13 (10). pp. 1777-1784. ISSN 0925 9635

Full text not available from this repository. (Request a copy)

Abstract

Nanocrystalline TiN (nc-TiN) has been imbedded in amorphous silicon nitride (a-SiNx) matrix to form a nanocomposite thin film (nc-TiN/a-SiNx) via magnetron sputtering. Adjusting Ti and Si3N4 target power ratio alters film composition, morphology, microstructure and residual stresses. The effects of silicon nitride target power density on surface morphology and residual stress have been studied. Atomic force microscopy (AFM) shows that the film surface becomes increasingly smoother and the roughness (Ra) drops from about 6 nm down to less than 1 nm as the silicon nitride target power density increases from 1.1 to 5.5 W cm−2. The surface topography is quantitatively described by calculation of two parameters: the interface width (w) and the lateral correlation length (ξ). The interface width (w) describes the vertical growth, and the lateral correlation length (ξ) characterizes the lateral growth of the surface. The growth-induced residual stress during the sputtering deposition of nc-TiN/a-SiNx nanocomposite thin film increases with sputtering power density, but only reaches about −1 GPa even at the highest experimented Si3N4 target power density of 5.5 W cm−2. The growth-induced stress is opposite in sign and roughly equal in quantity to the thermal stress induced by the difference in the coefficient of thermal expansion (CTE) between the films and the silicon wafer substrate. As a result, the magnetron sputtered nc-TiN/a-SiNx nanocomposite films become almost stress-free (as low as 0 to −0.15 GPa residual stress).

Item Type:	Article
Uncontrolled Keywords:	Nanocrystalline; Nitrides; Sputtering; Surface microscopy
Subjects:	F200 Materials Science
Department:	Faculties > Engineering and Environment > Mathematics, Physics and Electrical Engineering
Depositing User:	Becky Skoyles
Date Deposited:	26 Mar 2015 15:11
Last Modified:	12 Oct 2019 19:06
URI:	http://nrl.northumbria.ac.uk/id/eprint/21830

Downloads