Room temperature deposition of silicon by arrayed DC microplasmas

This paper reports room temperature deposition of silicon in spatially localized areas of a micro-chip through plasma-enhanced chemical vapor deposition (PECVD) using micro-plasmas. DC microplasmas are generated on a patterned Ti arrayed electrode structure employing multiple cathodes and a single anode. At the operating pressures used, the plasma glow is confined to the region directly over the powered cathodes only. Powering these microplasmas in a silane ambient allows selected deposition of silicon to only the energized cathodes. Silicon is deposited at 6.7-15.9 nm/min. corresponding to microplasma cathode power densities of 3.65-9.35 W/cm², with the substrate heated to 300°C. At room temperature deposition rates up to 7.5 nm/min. are realized. A new plasma coupling technique for creating controlled variations in a sub-array of unbiased electrodes is also described.