Stress in liquid-phase deposited oxide films

Abstract

To To develop a low-stress dielectric thin film, a novel liquid-phase deposition (LPD) technique utilizing silica-saturated hydrofluosilicic (H2SiF6) solution with only H2O added is proposed. Due to fluorine incorporation, the stress in as deposited LPD oxide can be as low as 83.3 MPa (tensile). Addition of H2O greatly affects the stresses in as-deposited LPD oxide: the less H2O added, the lower the stress will be. The stress variations accompanying thermal cycling have also been larger quantity of H2O added exhibited larger stress variations (hysteresis). After ex situ annealing at around 600 degrees C, the total stress decreased to near 0 MPa.