Low Dielectric Constant Amorphous SiBN Ternary Films Prepared by Plasma-Enhanced Deposition

Abstract

A novel insulation films named amorphous SiBN ternary films are investigated. These films have been prepared by plasma-enhanced chemical vapor deposition using SiH 4 –B 2 H 6 –NH 3 –Ar mixture. The dependences of film properties on film composition are systematically investigated. It is found that these films show good insulation characteristics and conformal step coverage. These films can be easily etched by reactive ion etching using H 2 /CF 4 gas mixture. Very low dielectric constant lower than that of silicon dioxide is realized when the B atomic ratios are beyond 0.30. Boron nitride shows hygroscopic properties while stability to moisture is confirmed for SiBN films. Therefore SiBN films will be applicable as inter-layer insulation in a low parastic capacitance multi-level metallization.