Effect of substrate roughness and material selection on the microstructure of sputtering deposited boron carbide thin films

Amorphous boron carbide (B4C) thin films are by far the most popular form for neutron converting layers in 10B-based detectors, which a rising trend detector technologies response to increasing scarcity and price of 3He, standard material detection. The microstructure B4C is closely related important properties, e.g. density adhesion, layers, eventually affect detection efficiency long-term stability detectors. To study influence from substrates different roughness materials, were deposited on polished Si with Al, Ti, Cu buffer unpolished Si, direct current magnetron sputtering at substrate temperature 623 K. tapered columnar grains nodular defects, generally observed SEM images, indicated strong shadowing effect where voids introduced around grains. change grain size did not show dependence roughness, acquired surface profile, nor mass films, obtained reflectivity patterns. However, non-uniform high skewness, leading drop ~95 % down ~70 tabulated bulk density. On other hand, similar microstructures good adhesion cross-cut tests, showing reliability common structural materials