SEMICONDUCTOR DEVICE WITH SILICON NITRIDE AND ITS PRODUCTION

摘要

PURPOSE: To keep the ultraviolet transmissivity and low strain inside film and improve the covering property by allowing the optical absorption edge wavelength of a silicon nitride film covering an element to which ultraviolet irradiation is required, to be shorter than a specific wavelength and enlarging an average area of an area surrounded with a crystal grain boundary on the surface of the silicon nitride than a specific size. CONSTITUTION: The optical absorption edge wavelength of a silicon nitride film 25 which is formed in a manner to cover an element needing ultraviolet irradiation is made shorter than 254nm and the average area of an area surrounded with crystal grain boundary appearing on the surface of the film 25 is made at least 4.5×10<4> nm<2> . The film 25 is formed by changing a mixed gas (the flow ratio of silane gas and ammonia gas to nitrogen gas is at least 0.050 and the flow ratio of silane gas to ammonia is less than 1.7) containing a silane gas, ammonia gas and nitrogen gas into plasma. Thus, the ultraviolet transmissivity and low strain inside film can be kept and the covering property be improved at the same time.