Abstract:
For the first time, idea of the influence of grain orientation and size on mechanical properties of thin-film membranes had been presented.Testing was carried out using the example of thin-film Al/Mo materials on a Si wafer using blowing method. It had been experimentally confirmed that the horizontal size of Mo grains varies in the range from 27 to 67 nm, the size of Al grains varies from 166 to 502 nm, and the grains are oriented in a mutually perpendicular direction. The vertical grain size coincides with the film thickness for Mo at thicknesses up to 1130 nm and for Al at thicknesses up to 1000 nm. By varying the deposition sequence of Al and Mo layers, an increase in the critical burst pressure and biaxial elastic modulus by more than 50% is achieved. In particular, for a membrane with a diameter of 0.5 mm, the critical burst pressure increased from 3.32 to 5.77 atm, the biaxial elastic modulus from 400 to 691 GPa. The critical pressure increases significantly when using films with large grains oriented perpendicular to the direction of loading.