Determination of residual stress in thin films: a comparative study of X-ray topography versus laser curvature method

Bending induced electrical response variations in ultra-thin flexible chips and device modeling

“…[72][73][74] A comparison of Young's modulus E and the Poisson's ratio 68 of several materials frequently used in flexible electronics [e.g., singlecrystal Si, hydrogenated amorphous (a-Si:H), hydrogenated nanocrystalline Si (nc-Si:H), polycrystalline Si, Kapton V R , and polyethylene naphthalate (PEN)] is given in Table I. [75][76][77][78][79][80][81][82] The experimental techniques that have been used to study mechanical aspects of UTCs include (i) direct methods 83,84 such as xray diffraction 85,86 and micro-Raman spectroscopy 87,88 and (ii) indirect methods based on measuring the curvature 89 (e.g., optical interferometry, 90 laser scanning, 91,92 and microscope image monitoring in real time 43 ). The subsection below presents the uniaxial and biaxial bending in UTCs.…”

Large-Area Chip Attachment by Sintering Nanosilver Paste: Process Improvement by Nondestructive Characterization

“…A more detailed description of the curvature measurement technique and apparatus can be found elsewhere. [11,12] Figure 7 to Fig. 12 showed the transmission mode X-ray images for samples sintered under conditions in Table 1, respectively.…”

Measurement of residual stress of PZT thin film on Si(100) by synchrotron X-ray rocking curve technique

“…the film is under compression. Assuming the film thickness is much thinner than that of the substrate, the residual stress of the films can be deduced from the curvature of the substrate by the well-known modified Stoney equation [20].…”

“…Another group of methods calculates film residual stresses indirectly from the curvature of the sample surface or substrate due to balance/equilibrium between the forces and moments in the films and the substrate. The latter includes laser scanning technique [17,18], profilometry [19], double crystal diffraction topography (DCDT) [20,21], and optical interferometry [22]. X-ray diffraction sin 2 ψ method is well established and widely used in the measurement of residual stress of the thin films.…”

“…However, its measurement may be affected by the surface roughness and reflectivity of the samples [20] while double crystal diffraction topography (DCDT), which measures curvature of the crystalline plane of single substrate, is not affected by the surface conditions of the samples and does not require the elastic constants of the film.…”