Growth stress evolution in HfO2/SiO2 multilayers

Growth stress in hafnium oxide/silicon dioxide (HfO2/SiO2) multilayers was measured in situ to understand the role of the sublayers and the influence of the underlayers' structural features. Experiments using three- and six-layer films were performed by electron-beam evaporation. During deposition, the developing trend of the force per unit width was controlled by changing the thickness ratio of the HfO2 and SiO2 layers. The substrate material affected the initial stress evolution of HfO2 film. The structural feature of the HfO2 layer onto which SiO2 was deposited and the whole film thickness have a combined effect on the stress evolution of the SiO2 layer.

► Film radius stress relates to thickness ratio of sublayers.
► The initial stress evolutions of HfO2 depended on the substrate material.
► The structural feature of H layer affects the stress evolution of L layer.