Improvement of Adhesion Performances of CVD-W Films Deposited on B[sub 2]H[sub 6]-Based ALD-W Nucleation Layer

The resistivity of chemical-vapor-deposited (CVD)-W film was reported to be significantly reduced using a -based atomic layer deposited (ALD)-W nucleation layer for continuously shrinking memory devices. But, we found that the adhesion performances of CVD-W films growing on the -based ALD-W nucleation layer were poor compared to those on the -based W nucleation layer. Scanning electron microscopy and secondary ion mass spectrometry analysis clearly suggest that the boron penetration into the interface between underlying TiN and during the deposition of W nucleation layer is a possible reason to degrade the adhesion performances of CVD-W films with -based W nucleation layers. By rigorous selection of both the deposition conditions for W nucleation layer and diffusion barrier materials, we can demonstrate the successful deposition of CVD-W film with a very low resistivity of ( in thickness) without an adhesion failure. Noticeably, the application of thick sputter-deposited film as a glue layer was found to present an excellent adhesion performance, which was due to its excellent diffusion barrier performance with amorphous structure.