Generation and evolution of residual stresses in physical vapour-deposited thin films

Abstract

Residual stresses in films produced by physical vapour deposition (PVD) techniques result from the contribution of thermal, intrinsic and extrinsic stresses. Tensile intrinsic stresses are usually observed in not fully dense films deposited by thermal evaporation from non-energetic particles. Compressive intrinsic stresses develop in relatively dense films deposited at low temperatures under energetic particle bombardment. Various models proposed in the literature to explain the origin of intrinsic stresses in PVD films are presented. In addition to thermal and intrinsic stresses, extrinsic stresses may be found in porous films exposed to room air or polar molecule vapour. Stress data for films deposited by magnetron sputtering and thermal evaporation are presented and discussed.