Chemical Vapor Deposition of Silicon Carbonitride Films

Chemical vapour deposition (CVD) of silicon carbonitride (SiCN) films encompasses a range of techniques in which volatile organosilicon precursors are decomposed—thermally or via plasma—to deposit conformal, amorphous or nanostructured Si–C–N coatings on substrates. By adjusting deposition parameters such as substrate temperature, reactor pressure, gas flow ratios and plasma or filament conditions, it is possible to tailor the stoichiometry, bonding environment and microstructure of the resulting film. The incorporation of nitrogen into silicon carbide matrices enhances fracture resistance, high-temperature stability and resistance to oxidation, while tuning of carbon content and hydrogen incorporation can modify optical bandgap and refractive index. Plasma-enhanced CVD (PECVD) and inductively coupled plasma CVD (ICP-CVD) routes enable low-temperature growth of hydrogenated amorphous SiCxNy:H layers with controllable chemistry, whereas hot-wire CVD introduces reactive radical species via catalytic filament decomposition to yield dense, low-damage films. SiCN coatings find applications as diffusion barriers in microelectronics, protective hard coatings in harsh environments, optical layers with engineered bandgaps and direct-bonding dielectrics. Recent efforts emphasise in situ diagnostics, long-term stability under ambient conditions, and integration of low-temperature deposition for advanced heterogeneous device assembly.

Research from Nature Portfolio

Recent studies have demonstrated that nitrogen-doped amorphous silicon carbide films deposited by magnetron sputtering exhibit markedly improved tribo-mechanical performance when compared to pure SiC. By varying the nitrogen content up to 40 at.% and annealing in air or vacuum at temperatures up to 1100 °C, it was shown that C≡N bond formation and suppression of SiC cluster crystallisation lead to enhanced hardness, ductility and scratch resistance. The optimised Si0.32C0.32N0.36 composition achieved a balance of high hardness (>20 GPa) and fracture resistance, maintained after thermal exposure, highlighting the role of nitrogen in tuning mechanical durability for high-temperature applications.

Chemical Vapor Deposition of Silicon Carbonitride Films publication trend

The graph below shows the total number of articles in chemical vapor deposition of silicon carbonitride films across all publications each year (not limited to Nature Index journals).

Technical terms

Chemical vapour deposition (CVD): A process in which gaseous precursors react or decompose on a heated substrate to form a solid film.

Plasma-enhanced CVD (PECVD): A CVD variant using plasma to lower reaction temperatures and activate precursor species.

Hot-wire CVD (HWCVD): A technique where a heated filament catalyses precursor decomposition, generating radicals for film growth.

Amorphous silicon carbonitride (a-SiCxNy): A non-crystalline ternary ceramic combining silicon, carbon and nitrogen bonds for enhanced mechanical and optical properties.

Stoichiometry: The elemental composition ratios in a compound or film, key to defining its structure and properties.

References

1. Hot Wire Chemical Vapor Deposition Chemistry in the Gas Phase and on the Catalyst Surface with Organosilicon Compounds. Accounts of Chemical Research (2015).
2. Effect of Nitrogen Doping and Temperature on Mechanical Durability of Silicon Carbide Thin Films. Scientific Reports (2018).
3. Influence of Deposition Conditions on the Characteristics of Luminescent Silicon Carbonitride Thin Films. ECS Journal of Solid State Science and Technology (2018).
4. Synthesis, Properties and Aging of ICP-CVD SiCxNy:H Films Formed from Tetramethyldisilazane. Coatings (2022).