Self-aligned TiN Formation by N₂ Plasma Bias Treatment of TiSi₂ Deposited by Selective Chemical Vapor Deposition

The titanium nitride (TiN) formation technology described here uses nitrogen plasma bias treatment to form self-aligned TiN only on the diffused layer from titanium silicide ( TiSi 2 ) prepared by selective chemical vapor deposition (CVD). The nitriding was performed using magnetron sputtering equipment with an rf plasma source. Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), and etching in 1% HF were used to characterize the samples. The contacts fabricated with the Al-2%Si/TiN/TiSi 2 /Si barrier technology exhibit low resistivities of about 10 -7 Ω·cm 2 . No excessive leakage of the 0.2-µm shallow junctions was observed even after thermally stressing the samples at 500°C for 30 min.