Modeling of agglomeration in polycrystalline thin films: Application to TiSi2 on a silicon substrate

Abstract

An equilibrium model for agglomeration in polycrystalline thin films which considers the energy balance between the grain boundary energy and both surface and substrate interface energies is presented. It predicts that small grain size, low grain boundary energy, and high film surface and interface energies should promote resistance to agglomeration, and shows that the substrate-film interface can play a significant role in the process. It also predicts a critical grain size limiting formation of a discontinuous island structure. This easily calculable value is significantly smaller than that found in previous modeling. The critical grain size, the importance of the substrate interface, and some of the assumptions are shown to be consistent with transmission microscope observations of TiSi2 thin films deposited on Si substrates.

Agglomeration of Copper Thin Film in Cu/Ta/Si Structure

“…[7][8][9] In the thin film device fabrication, the agglomeration of copper films should be a serious problem and an important factor for the fabrication of interconnecting wires with excellent resistance against electromigration. The agglomeration of copper thin films has been studied so far mainly about the influence of annealing temperature 10,11) but there was no consideration about the agglomeration progress with annealing time.…”

Texture in thin film silicides and germanides: A review

“…These NiSi (112) agglomeration of a silicide/germanide film is considered to be a reduction of the surface and interface energy. 122,124 However, from the TEM cross-section visible in the bottom left of Fig. 21, it seems that for an agglomerated NiSi film, only the silicide/silicon interface is severely roughened while the surface remains flat, suggesting that minimizing the interface energy is the main driving force for the agglomeration.…”

“…High energy interfaces are colored in red, while the medium (axiotaxy) and low (epitaxy) energy interfaces are indicated by dashed or full green lines, respectively. Typically, grain growth in a single phase is assumed to happen through a process called grain boundary grooving, 39,124 where mass transport occurs from the high energy grain boundaries towards the grain/substrate interface of the grain with the lowest interface energy, resulting in a grooving of the grain boundary. This would imply that randomly oriented grains will be consumed by epitaxial and axiotaxial grains which have a significantly lower interface energy (Fig.…”

Phase-field model for grain boundary grooving in multi-component thin films

“…The grain boundary grooving phenomenon has been known and studied theoretically for some time [2,3,4,5,6]. Grooving is a general phenomenon which occurs at the free surface of all polycrystalline materials.…”