Static and dynamic characterization of AlN and nanocrystalline diamond membranes



In this work, AlN and nanocrystalline diamond thin films as well as multi-layer structures on their basis are characterized towards their mechanical properties. In particular, the Young's modulus E and the residual stress σ are obtained by wafer bow measurements of thin films as well as by bulge experiments and vibration measurements of freestanding membranes. Depending on the growth conditions, the AlN thin films, deposited by reactive magnetron sputtering, revealed values of σ ∼ +300 up to +400 MPa and E ∼ 370 GPa, while the diamond films, grown by microwave plasma CVD, showed values of σ ∼ −60 to +60 MPa and E ∼ 870 up to 1000 GPa. The values and the accuracy of the characterization techniques used are discussed and their limits are demonstrated.