Preparation of SiO2 on an InP substrate by a sol-gel technique for integrated optics

In this paper, we report our success in depositing sol-gel derived silica films on InP using multiple spin coating and rapid thermal processing. The effect of rapid thermal process temperature and time duration on the property of the film is studied. The dependence of the single layer thickness as well as its refractive index upon the film preparation parameters have been obtained and are compared with that on silicon substrates. As a result of the study, a crack-free SiO2 film with a thickness of 0.5 micrometers has been successfully deposited on InP at a processing temperature of 450 degrees C. We believe that our experimental result has indicated that it is possible to fabricate hybridized integrated optics devices on compound semiconductors through the sol-gel route.