Influence of oxygen partial pressure on HfO2 residual stresses and its finite element analysis

HfO2 films were prepared by electron beam evaporation on K9 glass. Oxygen flux was varied in the range of 0 mL/min to 25 mL/min by step of 5 mL/min (under standard condition). The residual stress was measured by viewing the substrate deflection using ZYGO interferometer. The results show that, as the oxygen pressure increases, the residual stresses decrease gradually from tensile to compressive, and then increase. The changes may be due to the variation of the microstructure of the HfO2 films, which was inspected with X-ray diffraction(XRD). The finite element software ansys was used to calculate the substrate deflection which was then compared with the measured data. The comparison proves that our model is right and it helps to conduct analyses on HfO2/SiO2 stack stresses.