Mechanical Properties of Membrane
thickness of multi-stack membrane is chosen to insure that the structure is mechanically stable
tensile nature of the silicon nitride + compressive nature of the silicon diode
- combination of these films --> weak tensile
- ratio of silicon dioxide to silicon nitride thickness is optimized to about 3 to 3.5 --> the residual stress of the composite membrane is 0.1 to 0.3 GPa
- ratio of 2: possibly cracking due to excessive tensile stress
- ratio of 5: possibly bucking due to excessive compressive stress
actual mechanical properties of films are strongly influenced by deposition methods and condition