Fabrication of a low resistivity tantalum nitride thin film

Novel bilayer TaN film has been developed using reactive ion DC sputtering. The film has a low resistivity of ∼80 μΩ-cm and is more stable compared with high resistivity films with high nitrogen flow rates. Low angle X-ray diffraction results show that the low resistivity TaN film is highly crystallized than that of each individual film deposited in the bilayer design. The crystalline structure and the film resistivity of the bilayer TaN film remain unchanged even when the thickness of each layer is changed, indicating large process window, that is critical for high volume manufacturing.