title: Analysis of long-term internal stress and film structure of SiO2 optical thin films.
abstract: Recently, the demand for durability of optical thin films, which have long been used, has been growing as the performance of optical components improves. The stress of a film is an important parameter that is related to its adhesion. The electron beam (EB) and ion-assisted deposition (IAD) methods are widely used to fabricate optical thin films. However, there are few reports on long-term internal stress, despite the importance of this issue. Here we discuss the time dependence of the stress of SiO2 optical thin films in terms of optical characteristics in the infrared region. It was found that SiO2 thin films prepared by the EB and IAD methods exhibited compression stress. The Si-OH molecular bond was observed at around 930 cm(-1) in the Fourier transform infrared spectroscopy spectrum of the sample prepared by the EB method, which exhibited a large change in internal stress after an elapsed time. It is considered that this change in bonding was related to the decrease in the stress of the films.
authors: Course of Electro Photo Optics, Graduate School of Tokai University, Hiratsuka, Kanagawa, Japan.
authors: Toshiyuki
authors: T
authors: Nishikawa
authors: Hiroi
authors: H
authors: Ono
authors: Hiroshi
authors: H
authors: Murotani
authors: Yoshitaka
authors: Y
authors: Iida
authors: Katsuhisa
authors: K
authors: Okada