TY - JOUR
T1 - In situ scanning tunneling microscopy studies of the evolution of surface morphology and microstructure in epitaxial TiN(001) grown by ultra-high-vacuum reactive magnetron sputtering
AU - Karr, Brian W.
AU - Petrov, I.
AU - Desjardins, P.
AU - Cahill, David G.
AU - Greene, J. E.
N1 - Funding Information:
This work was supported by the U.S. Department of Energy Grant DEFG02-96-ER35439 through the University of Illinois Materials ResearchL aboratory, the NSF/‘DARPA VIP Program, and the Joint Services Electronics Program. TEM and X-x studiesu sed the facilitiesof-the Center for Microanalysis of Materials.
PY - 1997/10
Y1 - 1997/10
N2 - The group IV-B transition metal nitride TiN is widely employed as a wear-resistant coating on mechanical components and as a diffusion barrier in microelectronic devices. We use the epitaxial growth of TiN as a model system for insight on the evolution of surface morphology and microstructure in more complex polycrystalline films. Atomically-flat MgO(001) substrates, prepared by air annealing at 950°C for 12 h, are verified by atomic force microscopy (AFM). Epitaxial TiN layers are grown by reactive magnetron sputter deposition in pure N2 at 650 ≤ Ts ≤ 750°C. Scanning tunneling microscopy (STM) results show that the development of surface morphology is dominated by growth mounds with an aspect-ratio of ≈ 0.006; both the roughness amplitude and average separation between mounds follow an approximate power law dependence on film thickness, tγ, with γ = 0.25 ± 0.07. The films grow in a two-dimensional multilayer mode in which island edges exhibit dendritic geometries characteristic of limited step-edge mobility. Transmission electron microscopy (TEM) shows that the films are epitaxial with dislocation loops on {111} planes and 〈001〉 misfit dislocations at the interface. Low-energy N+2 ion irradiation during film growth leads to surface smoothing with the smoothest layers, having a surface width of ≅ 0.22 nm, obtained with Vs = 43 V. Increasing Vs ≥ 43 V leads to surface roughening with decreased in-plane length scales.
AB - The group IV-B transition metal nitride TiN is widely employed as a wear-resistant coating on mechanical components and as a diffusion barrier in microelectronic devices. We use the epitaxial growth of TiN as a model system for insight on the evolution of surface morphology and microstructure in more complex polycrystalline films. Atomically-flat MgO(001) substrates, prepared by air annealing at 950°C for 12 h, are verified by atomic force microscopy (AFM). Epitaxial TiN layers are grown by reactive magnetron sputter deposition in pure N2 at 650 ≤ Ts ≤ 750°C. Scanning tunneling microscopy (STM) results show that the development of surface morphology is dominated by growth mounds with an aspect-ratio of ≈ 0.006; both the roughness amplitude and average separation between mounds follow an approximate power law dependence on film thickness, tγ, with γ = 0.25 ± 0.07. The films grow in a two-dimensional multilayer mode in which island edges exhibit dendritic geometries characteristic of limited step-edge mobility. Transmission electron microscopy (TEM) shows that the films are epitaxial with dislocation loops on {111} planes and 〈001〉 misfit dislocations at the interface. Low-energy N+2 ion irradiation during film growth leads to surface smoothing with the smoothest layers, having a surface width of ≅ 0.22 nm, obtained with Vs = 43 V. Increasing Vs ≥ 43 V leads to surface roughening with decreased in-plane length scales.
KW - Epitaxial titanium nitride
KW - Reactive magnetron sputtering
KW - Scanning tunneling microscopy
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U2 - 10.1016/S0257-8972(97)00444-1
DO - 10.1016/S0257-8972(97)00444-1
M3 - Article
AN - SCOPUS:0031248199
SN - 0257-8972
VL - 94-95
SP - 403
EP - 408
JO - Surface and Coatings Technology
JF - Surface and Coatings Technology
ER -