Density measurement of thin-films for micro-electromechanical systems using micro-cantilever structures

The use of micro-cantilever test structures for determining the density of thin film materials is reported. A range of micro-cantilever test structures has been fabricated using silicon, silicon nitride and silicon carbide which are materials that are commonly used in the fabrication of micro-electromechanical systems. The density of each material was determined by combining load–deflection and resonant frequency measurements, and using the Euler–Bernoulli equation for single clamped beams. The density values obtained were 2.35, 3.16 and 3.18 g/cm3 for silicon, silicon carbide and silicon nitride respectively. These values of density for these thin films agree very well with the values quoted in the literature.