Enhanced resistance property between ALD-Ru and W by controlling oxygen behavior with post Ru deposition annealing

Abstract

A method to eliminate an oxide layer formed on landing pad during the atomic layer deposition (ALD) of Ruthenium (Ru) was investigated with post-deposition annealing (PDA). The study demonstrates that PDA at 600 °C in a H2/Ar forming gas atmosphere effectively removes the oxide layer at the Ru and tungsten (W) interface. The behavior of interfacial oxygen with increasing PDA temperature was confirmed by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The resulting improvement in contact resistance was confirmed by measuring the resistance of string pattern before and after PDA. This work offers a potential solution for integrating Ru in DRAM capacitors by addressing the challenge posed by Ru ALD.