Influence of SiH4 on the WNx-PECVD process

Silane was added to an existing WNx PECVD process in different flow ratios to the WF6, to obtain higher thermal stability of the barrier in comparison to the WNx. The deposition rate rises drastically with increased SiH4/WF6 ratios. The ternary compositions were investigated with regard to the sheet resistance and thickness. The X-ray diffraction (XRD) measurements of selected layers with low electrical resistivities in the as-deposited state show a broad amorphous peak like the WNx barrier, indicating an amorphous structure. After characterising the as-deposited state of these samples, thermal treatments of the layers were performed at temperature of 600degreesC for 1 h in vacuum. (C) 2003 Published by Elsevier B.V.