Effect of substrate bias and hydrogen addition on the residual stress of BCN film with hexagonal structure prepared by sputtering of a B_4C target with Ar/N_2 reactive gas

摘要

The effect of substrate bias voltage and hydrogen addition on the residual stress of BCN film with hexagonal structure (hBCN) was investigated. The hBCN films were deposited on silicon (100) substrates by the sputtering of a B_4C target with a gas mixture of Ar (25 sccm) and N_2 (5 sccm) at a chamber pressure of 0.27 Pa. A compositional gradient B-C-N buffer layer was introduced before the deposition of the hBCN film. The compressive residual stress of the hBCN film was observed to decrease from 5.5 GPa to 4.5 GPa with the increase in the substrate bias voltage from -200 V to -300 V. By the addition of hydrogen (5 sccm), the compressive residual stress of the hBCN film deposited at a substrate bias voltage of - 300 V was observed to be reduced further to 3.0 GPa. The stress reduction occurred in the hBCN film by an increase in the substrate bias voltage, and hydrogen addition is due to a change in the alignment of hBCN (0002) planes, which is closely related to the penetration probabilities of argon ions into the film.