Evolution of tensile residual stress in thin metal films during energetic particle deposition

摘要

Physical-vapor-deposited thin metal films oftenexhibit tensile residual stresses. We studied the stress evolution inthin Cr films and found that increasing bombardment withenergetic particles (atoms or ions) at low energies leads to anincrease of tensile stress to a maximum followed by a rapiddecrease. Microstructural characterization by transmission electronmicroscopy revealed that two different microstructures areobserved for the same level of tensile stress: films processed atlow bombardment had columnar porosity while no porosity wasobserved in films processed at higher bombardment. The observedstress evolution is interpreted by energetic particle bombardment.