Stresses in passivated lines from curvature measurements Original Research Article

An exact expression is presented which enables the determination of volume-averaged thermoelastic stresses in passivated lines based on information from curvature measurements. This method, which is valid for lines of arbitrary in-plane shape, requires knowledge of the material properties of the line and passivation. The sensitivity of the line stress estimates to uncertainties in curvature data for a typical line/passivation geometry is investigated in detail. It is concluded that the present approach is well suited for Al or Cu lines embedded in SiO2 passivation. In the particular case of coinciding shear moduli or Poisson ratios for the line and passivation, it is shown that the method breaks down and only certain linear combinations of the line stress components may be determined.