The effect of surface roughness on the resistivity increase of thin metal films during gas adsorption

1987 ◽  
Vol 42 (1) ◽  
pp. 87-90 ◽  
Author(s):  
H. -U. Finzel ◽  
E. Schmiedl ◽  
P. Wi�mann
1996 ◽  
Vol 441 ◽  
Author(s):  
G. S. Was ◽  
D. J. Srolovitz ◽  
Z. Ma ◽  
D. Liang

AbstractA strategy was developed for controlling hillock formation in thin metal films by controlling the fiber texture to be of a relatively “weak” orientation. Two-dimensional molecular dynamics (MD) simulations were performed to determine the parameter dependencies of texturing under ion beam assisted deposition. Simulations showed that even for film orientations that have a lower number of nearest neighbor surface bonds, the reduction in sputtering rate by ion channeling will favor the growth of the grains aligned with their channeling direction in the direction of the ion beam. Higher energies should result in greater sputtering and a higher surface roughness. Confirmatory experiments were performed by growing Al films using ion beam assisted deposition in which the Ne ion beam was normal to the substrate surface. For all energies above 0 eV/atom, the fiber texture contained a (220) component and, at high normalized energies, the fiber texture was heavily (220) dominated. Subsequent annealing at 450°C for 30 min. resulted in hillock formation in the PVD (physical vapor deposition) condition, a reduction in the hillock density by two orders of magnitude in the 120 eV/atom condition and complete elimination of hillocking above 800 eV/atom. Although the surface roughness increased with ion beam energy as modeled by MD, the surface became smoother during annealing. These results show that the fiber texture can be controlled in a thin metal film in such a way as to eliminate hillock formation, that molecular dynamics simulation is a valuable predictive tool for guiding experiments in the development of thin film microstructures and that ion beam assisted deposition is an effective, practical tool for controlling microstructures of thin metal films.


Author(s):  
L. M. Gignac ◽  
K. P. Rodbell

As advanced semiconductor device features shrink, grain boundaries and interfaces become increasingly more important to the properties of thin metal films. With film thicknesses decreasing to the range of 10 nm and the corresponding features also decreasing to sub-micrometer sizes, interface and grain boundary properties become dominant. In this regime the details of the surfaces and grain boundaries dictate the interactions between film layers and the subsequent electrical properties. Therefore it is necessary to accurately characterize these materials on the proper length scale in order to first understand and then to improve the device effectiveness. In this talk we will examine the importance of microstructural characterization of thin metal films used in semiconductor devices and show how microstructure can influence the electrical performance. Specifically, we will review Co and Ti silicides for silicon contact and gate conductor applications, Ti/TiN liner films used for adhesion and diffusion barriers in chemical vapor deposited (CVD) tungsten vertical wiring (vias) and Ti/AlCu/Ti-TiN films used as planar interconnect metal lines.


Sign in / Sign up

Export Citation Format

Share Document