Growth and physical structure of amorphous boron carbide deposited by magnetron sputtering on a silicon substrate with a titanium interlayer

Multilayer amorphous boron carbide coatings were produced by radiofrequency magnetron
sputtering on silicon substrates. To improve the adhesion, titanium interlayers with different thickness
were interposed between the substrate and the coating. Above three hundreds nanometer, the enhanced
roughness of the titanium led to the growth of an amorphous boron carbide with a dense and continuing
columnar structure, and no delamination effect was observed. Correspondingly, the adhesion of the coating
became three time stronger than in the case of a bare silicon substrate. Physical structure and microstructural
proprieties of the coatings were investigated by means of a scan electron microscopy, atomic
force microscopy and X-ray diffraction. The adhesion of the films was measured by a scratch tester.