| Title |
Time Dependent Dielectric Breakdown Characteristics of Cu(Mg) Films |
| Authors |
안정욱(Jeong Uk An); 황상수(Sang Su Hwang); 박영배(Young Bae Park); 주영창(Young Chang Joo) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Cu(Mg); Reliability; Time dependence dielectric breakdown; Time to failure; Cu drift |
| 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) |