Temperature influence on the deposition of nitrogen-doped SiC polycrystalline films

Polycrystalline nitrogen doped cubic silicon carbide (3C-SiC) thin films, are grown on 2” Si wafers by low-pressure chemical vapor deposition (LPCVD) technique with the aim to be used as support and active material in microelectronic devices for neural interfaces. The effect of deposition temperature on the structural, mechanical and electrical properties is investigated. Growth rate is varying from 1 μm/h to 14 μm/h, along with the deposition temperature. We show that the structural and electrical properties of polycrystalline SiC are modified when changing the deposition temperature. Films with resistivity as low as (10.0 ± 0.5) mΩ·cm, low residual stress of (-397 ± 158) MPa and low root mean square surface roughness of (53 ± 19) nm are achieved. Accelerated aging tests in heated phosphate buffer solution (PBS) show an etching rate less than 1 nm/day and a steady low electrical resistivity for 77 days indicating that the nitrogen-doped polycrystalline SiC is a chemically stable material, capable of chronic stability in a saline electrolyte.