Determination of the adhesion energy of MEMS structures by applying Weibull-type distribution function

A novel test method to determine the adhesion energy of various MEMS surfaces in contact is presented. The method is based on an energy equilibrium state consideration between mechanical deformation energy and adhesion energy. The adhesion energy of the measurement structures is determined by means of pull-off tests and the results are modelled using a Weibull-type distribution function for stiction. In contrast to previous test methods, based on the same physical principle, our new method not only allows to characterize various materials but also various surface geometries. For a contact pair of a circular silicon disc of 200mm in diameter and of a silicon substrate both covered with native oxide we measured under atmospheric conditions the average adhesion energy as to be 0.13mJ/m2. The low value of adhesion energy is due to the curvature of one contact face.