Application And Improvement Of Silicon Nitride In Copper Interconnection Of Integrated Circuits

With the IC develop asMoore’s low described, the transistor critical dimension becomes smaller and smaller, level of integration higher and higher, the BEOL (Back End of Line) metal inter-connecter of IC becomes much more important for IC’s working speed and power dissipation. As IC manufacturing methodology scale down to 0.13um, because of copperhas muchmore advantages suchas the lowresistivity, theanti-electro-migration, etc., it replaces aluminum; meanwhile, the property of difficult to form volatile compound of copper was working out as dual damascene technical applied, it promotes the copper connection develops at full speed.But new technical methodology introduces new problems. Silicon nitride, which deposit with PECVD, is applied as copper barrier layer, and it is deposit on the surface of the wafer while copper CMP process completed. But, silicon nitride deposition process often induce metal line insulation issue, that is means wafer suffer VBD fail issue at WAT test.This thesis based on the theory of PECVD and combines with practical status, design experiments of copper oxide treatment and main deposition step of silicon nitride deposition recipe, digs out the root cause which induce VBD fail, then improve the step of copper oxide treat and SiH4 gas flow control of main deposition of the silicon nitride deposition recipe and reach to best.In addition, MIM capacitance replaces PIP or MIS widely applied to RF IC and mixed/analog IC since its properties of lower stray capacitance and lower contact resistance. As the requirement of integrated level improve, the capacitance density needs to improve, so silicon nitride replaces silicon oxide as MIM insulator since its properties of higher dielectric constant and high process compatibility. But it occur that MIM burn out at the practical application.As analyses the fail module of MIM burn out, design related experiments of silicon nitride deposition process and copper hillock improve procedure, find out the root cause, and optimize the silicon nitride deposition recipe which applied as MIM insulator. And introduce silicon nitride’s TDDB reliability test While verify the quality and for quality control. At the end, we applied the new recipe of silicon nitride deposition at MIM insulator to examine the quality.