Effects of B2H6 Pretreatment on ALD of W Film Using a Sequential Supply of WF6 and SiH4

The effects of diborane pretreatment on atomic layer deposition (ALD) of tungsten (W) thin film using a sequential supply of and on thermally grown and TiN films at 300°C were investigated. The results show that the pretreatment reduces the incubation time for film growth. X-ray photoelectron spectroscopy and scanning electron microscopy analysis suggest that elemental B on , released during pretreatment, induce rapid W nucleation. The drastically improved step coverage of ALD-W film is achieved at the ultrahigh aspect ratio contact (height: and top diameter: ) by the enhanced nucleation and growth via pretreatment. The effects of pretreatment on the properties of ALD-W films such as roughness, phase, microstructure, and resistivity are also investigated.