Calibrated measurements of elastic limit, modulus, and the residual stress of thin films using micromachined suspended structures

Calibration of the suspended square membrane method using both finite-element methods (FEM) and comparison with conventional tensile tests is discussed. The use of suspended circular membranes to measure the elastic limit of thin films is reported. The techniques can be adapted to other thin films from which microfabricated specimens can be made. The Instron test results provided useful information about the material behavior, including Young´s modulus, whereas the membranes were used to determine quantitative values for residual stress and elastic modulus. The axisymmetric state of circular membranes under pressure were utilized effectively in determining the elastic limit of thin polymer films.<>