Stresses in passivated lines from curvature measurements

An exact expression is presented which enables the determination of volume- averaged thermoelastic stresses in passivated lines based on information fr om curvature measurements. This method, which is Valid for lines of arbitra ry in-plane shape, requires knowledge of the material properties of the lin e and passivation. The sensitivity of the line stress estimates to uncertai nties in curvature data for a typical line/passivation geometry is investig ated in detail. It is concluded that the present approach is well suited fo r Al or Cu lines embedded in SiO2 passivation. In the particular case of co inciding 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. (C) 2000 Acta Metallurgica In c. Published by Elsevier Science Ltd. All rights reserved.