Homogeneous tungsten chemical vapor deposition on silane pretreated titanium nitride

Homogeneous nucleation of tungsten chemical vapor deposition (CVD) films on metallorganic (MO) CVD TiN substrates has been achieved by pretreating the substrate with SiH4 at a wafer susceptor temperature of 425 degrees C. Deposition of approximately a monolayer of silicon from the SiH4 pretreatment results in continuous, uniform tungsten films less than 200 Angstrom thick. Tungsten nucleation films grown on MOCVD TiN without a SiH4 pretreatment were heterogeneous, with tungsten islands not coalescing into a continuous film until the thickness reached 400 Angstrom. Experimental results are presented along with implications for use of tungsten CVD for vertical interconnects in high aspect ratio vias. (C) 1999 The Electrochemical Society. S1099-0062(99)02-089-1. All rights reserved.