text: During thin film growth, there can be a balance between surface energy and internal strain, with surface stress a coupling term combining the two. Instead of growing as a continuous thin film, a morphological instability can occur and the film can start to become very uneven, in many cases due to a breakdown of a balance between elastic and surface energies. The surface stress can lead to comparable wrinkling in nanowires, and also a morphological instability in a thin film.