Scanning Magnetron Sputtered Tin Coatings as Diffusion Barrier for Silicon Devices

Scanning magnetron target (274mmx174mm) is used to deposit TiN film on to Si (less than100greater than p type 10 ohm cm resistivity) substrate for microelectronic application. To deposit best quality TiN films with low resistivity1, parameters. Such as deposition rate, scanning speed, target substrate distance (T. S. D. ) and ion current ma, Nitrogen partial pressure, were optimized. Total nitrogen and argon pressure was kept at 5x10-3 m bar. TiN films were sputter deposited on to Si with different substrate bias. Cu film is sputter deposited on to as deposited TiN films since it is found as best substitute for diffusion barrier. Thickness of the TiN film is determined keeping in consideration diffusion length2 of Cu in TiN at different temperature. Stylus Dektak is used to obtain desired thickness of TiN and copper films. Cu /TiN /Si Structure thus formed were annealed at different temperature to study microelectronic application for diffusion barrier. Resistivity fig7of the Cu/TiN /Si structure were obtained using four probe method, low resistivity Cu/TiN/Si structure were preferred. Inter diffusion of silicon and or top metal through the TiN film was investigated. XRD fig 8 SEM fig 9, 10, 11 EDAX fig 12 of Cu/TiN /Si is obtained to determine its feasibility for microelectronic application.