Structure control of sputtered zinc oxide films by utilizing zinc oxide seed layers tailored by ion beam assisted sputtering

Reactively sputtered zinc oxide thin films typically exhibit a c-oriented (0 0 0 1) texture of low crystalline order when deposited on unheated substrates. The structural order can be significantly improved upon heating the substrates during deposition. Here it will be demonstrated that by utilizing c-textured seed layers, which are grown by an ion beam assisted sputtering (IBAS) process, films can be deposited at room temperature with significantly improved c-texture. These films are significantly less sensitive to detrimental oxygen ion bombardment. By tailoring the IBAS process, even seed layers with dominant a-texture can be produced. Subsequently thick ZnO films can be grown on appropriate seed layers which are pre-dominantly a-textured.