Residual stresses in thin film systems: Effects of lattice mismatch, thermal mismatch and interface dislocations

Multilayered graphene films prepared at moderate temperatures using energetic physical vapour deposition

“…This sample is suggestive of thin film failure due to residual stress although the exact source of this is unclear. The layer of carbon deposited (equivalent to about 5 nm or 15 graphene layers) is very thin to be exhibiting thermal and lattice-mismatch stress [45], which should in any case be relieved by the defect density of the copper-graphene interface. However the 'annealing effect' of the incoming carbon atoms may also leave a residual stress in the graphene surface particularly as it becomes more remote from the copper.…”

Temperature-dependent residual stresses in a hetero-epitaxial thin film system

“…However, it is formidable to accurately quantify the density of misfit dislocation in the 0.3 and 5 μm thin films and to reveal their difference using TEM. Our previous investigation [24] has shown that a change of 5% in dislocation density can lead to a difference of at least 600 MPa in the residual stress. Such a small change in misfit dislocation is extremely hard to discern using the TEM.…”

“…This shows that the silicon film is in the equi-biaxial stress state at all temperatures, even though the lattice mismatch strains are very different along the two orthogonal directions. It shall be noted that the more significant lattice mismatch brings about the more misfit dislocations (or the effect of them) for minimizing the strain energy [10,24]. .…”

“…For both the films, the decreasing rates of the residual stresses are almost identical. The residual stresses due to the CTE mismatch can be calculated by using the finite element (FE) method [24]. Since the sapphire substrate is more than 100 times thicker than the thin film, the calculated residual stresses are thicknessindependent [25].…”

Residual stress measurement on TiN thin films by combing nanoindentation and average X-ray strain (AXS) method

“…Measurement of residual stress in thin films and coatings is crucial for understanding the evolution of growth stress [1][2][3][4][5][6][7][8] or thermal stress [5,9], and thereby improving the performance and reliability of microelectromechanical, electronic, magnetic and optical devices [4,[10][11][12][13][14]. For most mechanical applications, residual stress may affect elastic modulus [15], critical shear strength or adhesion [16,17], and fracture toughness [18], which usually leads to film delamination or spallation, especially for coatings on microelectromechanical systems (MEMS) and protective coatings [19][20][21].…”