Mechanisms for Fatigue of Micron-Scale Silicon Structural Films
Abstract
Although bulk silicon is not susceptible to fatigue, micron-scale silicon is. Several mechanisms have been proposed to explain this surprising behavior although the issue remains contentious. Here we re- view published fatigue results for micron-scale thin silicon films and find that in general they display similar trends, in that lower cyclic stresses result in larger number of cycles to failure in stress-lifetime data. We further show that one of two classes of mechanisms is invariably proposed to explain the phe- nomenon. The first class attributes fatigue to a surface effect caused by subcritical (stable) cracking in the silicon-oxide layer, e.g., reaction-layer fatigue; the second class proposes that subcritical cracking in the silicon itself is the cause of fatigue in Si films. It is our contention that results to date from single and polycrystalline silicon fatigue studies provide no convincing experimental evidence to sup- port subcritical cracking in the silicon. Conversely, the reaction-layer mechanism is consistent with existing experimental results, and moreover provides a rational explanation for the marked difference between the fatigue behavior of bulk and micron-scale silicon.
Date of this Version
2-1-2007
Recommended Citation
Alsem, Daan Hein; Pierron, Olivier N.; Stach, Eric A.; Muhlstein, Christopher L.; and Ritchie, Robert O., "Mechanisms for Fatigue of Micron-Scale Silicon Structural Films" (2007). Birck and NCN Publications. Paper 48.
https://docs.lib.purdue.edu/nanopub/48
Comments
DOI: 10.1002/adem.200600269