Study of Ta-barrier and pore sealing dielectric layer interaction for enhanced barrier performance of Cu/ultralow /spl kappa/(/spl kappa/<2.2) interconnects

For Cu/ultralow /spl kappa/ application, understanding of interfacial interaction between Ta and pore-sealing layer over porous dielectric is very important in order to achieve a good barrier performance. However, characterizing the effect of pore-sealing layer on barrier performance poses a big challenge. Most studies monitored degradation of the electrical performance of the Ta barrier after integration process with little discussions on interfacial interaction. In this letter, the interaction at the interface between Ta and pore-sealing layer deposited over porous SiLK (/spl kappa//spl sim/2.2) film is investigated. The barrier performance is improved significantly by nitrogen incorporation during liner growth. This methodology is very effective for improving metal barrier and pore-sealing performance for Cu/ultralow /spl kappa/ interconnects.