MOCVD of tungsten nitride films using W(CO)(6) and NH3 for Cu diffusion barrier

Abstract

Tungsten nitride (WNx) films were deposited by metalorganic chemical vapor deposition (MOCVD) using W(CO)(6) and NH3 in the growth temperature range from 250 to 500degreesC. The growth rate was 0.3similar to193 nm/min. The film resisitivity decreased from 950 to 590 muOmega cm, and the impurity concentration of C and O both decreased from 10 to below 5% upon the temperature rise. X-ray diffraction (XRD) analysis showed that the film structure changed from an amorphous-like structure to a W2N(200) phase dominant polycrystalline structure with the temperature rise. Sheet resistance measurements and XRD analysis showed that the WNx barrier of a 15 nm thickness blocked the Cu diffusion efficiently up to 600degreesC for 1 h annealing. (C) 2004 The Electrochemical Society.