Nucleation kinetics versus nitrogen partial pressure during homoepitaxial growth of stoichiometric TiN(0 0 1): A scanning tunneling microscopy study

• Published in: Surface science Vol. 581; no. 2; pp. L122 - 127
• Main Authors: Wall, Marcel A., Cahill, David G., Petrov, I., Gall, D., Greene, J.E.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.05.2005; Amsterdam Elsevier Science; New York, NY
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Physics; Scanning tunneling microscopy; Surface diffusion; TiN; Titanium nitride; TiN; Titanium nitride; Scanning tunneling microscopy; Surface diffusion; Homoepitaxy; Inorganic compounds; Nucleation; Partial pressure; Transition element compounds; Kinetics; Nitrogen; Titanium nitrides
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/j.susc.2005.03.007

We grow homoepitaxial stoichiometric TiN(0 0 1) layers by ultra-high vacuum reactive magnetron sputtering in Ar/N 2 mixtures and use scanning tunneling microscopy to study nucleation as a function of the N 2 gas fraction f N 2 and growth temperature T s. The characteristic island size R c necessary to nucleate a new layer decreases continuously with f N 2 , varying from 18.0 nm at T s = 740 °C with f N 2 = 0.10 to 11.2 nm with f N 2 = 1.00 . Over the temperature range 600 ⩽ T s ⩽ 860 °C, nucleation is diffusion limited with an activation energy E s of 1.1 ± 0.1 eV for TiN(0 0 1) growth with f N 2 = 0.10 and 1.4 ± 0.1 eV in pure N 2. We attribute the increase in E s to a higher steady-state N coverage resulting in an increase in the average x-value of the primary surface-diffusing species, TiN x admolecules.