| Abstract |
| Electrical properties and time dependent dielectric breakdown (TDDB) characteristics of Cu (0.7 at.% Mg) alloy films are investigated to improve the reliability of Cu interconnects used in microelectronic devices. After Cu(Mg) films are annealed in vacuum at 400℃ for 30 min, resistivity decreases from 3.4 to 2.0 μΩcm and, thin and continuous MgO layers form both on Cu(Mg) film surface and on Cu(Mg)/SiO₂ interface. Metal-Oxide-Silicon (MOS) capacitors composed of Cu(Mg) film deposited on thermal oxide grown on Si wafer are subjected to bias temperature stressing at 180 through 220℃ under electric fields of 1.5 through 2.6 MV/cm. Median time to failure (MTTF) and activation energy of Cu(Mg)/SiO₂ are much larger than those of pure Cu/SiO₂. Cu drifts into dielectric are inhibited by the continuous Mg oxide formed at Cu(Mg)/SiO₂ interface which improve interfacial adhesion and finally lead to better interconnect reliabilities. (Received October 29, 2004) |
|
|
| Key Words |
| Cu(Mg), Reliability, Time dependence dielectric breakdown, Time to failure, Cu drift |
|
|
 |
|
