| 초록 |
Ruthenium (Ru) and iridium (Ir) films were deposited by atomic layer deposition (ALD) as a metal electrode for dynamic random access memory (DRAM) capacitor. Bis(ethylcyclopentadienyl)ruthenium [Ru(EtCp)2] and (ethylcyclopentadienyl)(1,5-cyclooctadien)iridium [Ir(EtCp)(COD)] were used as metal precursors, and oxygen (O2) gas was used as a reactant gas in both films. To confirm thermal stability of the films, high temperature annealing was performed in argon (Ar) and O2 ambient using rapid thermal annealing (RTA) system. While both Ru and Ir films remained stable after annealing in Ar ambient, surface roughening of the films was occurred in O2 ambient due to surface oxidation as annealing temperature was increased. Surface of Ir was much smoother than that of Ru because oxidation resistance of Ir is stronger than that of Ru and this result means that Ir is more suitable material for DRAM capacitor electrode. |
