PRODUCTION OF SILICON NITRIDE THIN FILM

摘要

PURPOSE:To form a silicon nitride thin film uniform in refractive index by carrying out film formation by sputtering with a target for sputtering in which the ratio between silicon nitride and silicon has been varied under specified conditions. CONSTITUTION:When a silicone nitride thin film is formed, film formation is carried out by sputtering with a target for sputtering in which the ratio between silicon nitride and silicon has been continuously or stepwise varied from a central part toward the outside. The refractive index of a film can be prevented from varying according to a slight change of the nitrogen content in sputtering gas at the time of film formation by sputtering and the objective silicon nitride thin film having a high refractive index and uniform in refractive index distribution can be produced by sputtering.