Specific Process Knowledge/Thin film deposition/Deposition of Tantalum Nitride

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Tantalum Nitride (TaN_x)

Tantalum nitride (TaNₓ, typically Ta₂N or cubic δ‑TaN) is a refractory ceramic that pairs very high melting temperature, extreme hardness, chemical inertness, and controllable electrical resistivity in a CMOS‑compatible matrix. Thin films are grown mainly by reactive magnetron sputtering; tuning nitrogen flow, substrate temperature, and energy lets engineers dial in stoichiometry, grain size, stress, and resistivity. Within semiconductor process flows, TaNₓ is the workhorse Cu diffusion barrier/liner, a stable gate or contact metal, a hard mask, and a precision thin‑film resistor in analog/RF circuits; its high absorption coefficient also makes it the standard absorber layer in EUV lithography photomasks. Optically, TaN‑based multilayers act as durable high‑temperature plasmonic and thermally emissive coatings, mid‑IR absorbers, and soft‑X‑ray mirrors for synchrotron beamlines and space telescopes, outperforming noble metals under extreme photon and thermal loads. Beyond electronics and photonics, TaN’s wear and oxidation resistance underpin MEMS springs, high‑temperature sensors, and corrosion‑resistant coatings, while many TaN phases become superconducting below ~4–8 K, enabling low‑loss microwave resonators, kinetic‑inductance detectors, and other cryogenic devices that benefit from its simultaneous mechanical robustness and diffusion‑barrier capability.

Deposition of Tantalum Nitride

Deposition of TaN_x can only be done by reactive sputtering using a Ta target.

The tool of choice for this application is the Cluster-based multi-chamber high vacuum sputtering deposition system, commonly referred to as the "Cluster Lesker." The operating process is described in detail.:

• Deposition of Tantalum Nitride (TaN) using reactive sputtering in Sputter-System Metal-Nitride(PC3) Source 2 (3-inch target)

At the moment (July 2025), we have a 3-inch Ta target (0.250" thick, nonbonded - mounted using the screw-through-target approach) for PC3 or PC1.

Comparison of sputter systems for reactive deposition

	Sputter-System Metal-Nitride(PC3)	Lesker sputter system
Generel description	reactive DC/Pulsed DC reactive HIPIMS (high-power impulse magnetron sputtering)	reactive DC sputtering (not tested)
Stoichiometry	Tunable	Tunable
Film thickness	Limited by process time. Deposition rate (0.2 nm/s) is likely faster than Sputter-System (Lesker)	Limited by process time. Deposition rate unknown
Process temperature	Up to 600 °C	Up to 400 °C (Room temperature from 2021)
Step coverage	Some step coverage possible	Some step coverage possible but amount unknown
Film quality	Deposition on one side of the substrate Properties including tunable stoichiometry (requires process development)	Deposition on one side of the substrate Unknown quality Likely O-contamination
Batch size	Many smaller samples Up to 10*100 mm or 150 mm wafers	Several smaller samples 1-several 50 mm wafers 1*100 mm wafers 1*150 mm wafer
Allowed materials	Almost any as long as they do not outgas and are not very toxic, see cross-contamination sheets	Almost any as long as they do not outgas and are not very toxic, see cross-contamination sheets