This paper will discuss two different techniques to measure mechanical properties of thin
film, bulge test and nano-indentation test. In the bulge test, uniform pressure applies to one side of
thin film. Measurement of the membrane deflection as a function of the applied pressure allows one to
determine the mechanical properties such as the elastic modulus and the residual stress.
Nano-indentation measurements are accomplished by pushing the indenter tip into a sample and then
withdrawing it, recording the force required as a function of position. . In this study, modified King’s
model can be used to estimate the mechanical properties of the thin film in order to avoid the effect of
substrates. Both techniques can be used to determine Young’s modulus or Poisson’s ratio, but in both
cases knowledge of the other variables is needed. However, the mathematical relationship between
the modulus and Poisson's ratio is different for the two experimental techniques. Hence, achieving
agreement between the techniques means that the modulus and Poisson’s ratio and Young’s modulus
of thin films can be determined with no a priori knowledge of either.