Low temperature ion beam sputter deposition of amorphous silicon carbide for wafer-level vacuum sealing

This paper presents a novel low temperature, wafer-level vacuum sealing method that uses line-of-sight deposition of amorphous SiC with ion beam sputter deposition. The ion beam sputter deposition system allows substrate tilting for off-normal deposition and operates with a pressure of approximately 3 times 10^-6 torr during deposition. The amorphous SiC films have demonstrated compressive intrinsic stresses for growth rates between 0.06 - 0.13 nm/min test scaffold structures were fabricated by etching holes and trenches into bare Si wafers. The topography of sealing films deposited on the test scaffold structures shows that the film growth is directional with no visible down-hole deposition. The termination of the seal and the chemical resistance of the sealing films have been confirmed with a hot KOH immersion experiment.