Abstract
Nb x Ta (1-x) N y O m C n diffusion barriers deposited by chemical vapor deposition (CVD) for copper metallization have been investigated. The barriers were deposited at 375 °C with tetrakis-diethylamido-niobium and pentakis-diethylamido-tantalum as precursors. Amorphous thin films can be obtained by thermal deposition at temperatures from 500 to 600 °C. The activation energy of the metal-organic CVD (MOCVD) process was determined to be 79.1±4.8 kJ/mol. By the incorporation of NH 3 gas into reactants, both MOCVD deposition temperature and carbon concentration in the Nb x Ta (1-x) N y O m C n films were reduced. In addition, NH 3 -plasma post-treatment was implemented to prevent oxygen from being introduced into the barrier films. © 2002 Elsevier Science B.V. All rights reserved.