| 摘要 |
PURPOSE:To bury the irregularities of a silicon nitride film with silicon, which is yielded by the decomposition of silane gas so as to flatten the surface and to improve protecting ability with acid resistance and waterproof property of silicon itself, by growing the silicon nitride film, stopping the flow of ammonia gas, and flowing only the silane gas for a short time. CONSTITUTION:The pressure of the inside of a reacting tube is reduced by a vacuum pump 8. Then, silane gas and ammonia gas are made to flow on a heated silicon wafer, and a silicon nitride film is grown by a conventional method. When the film having an intended thickness is obtained, a valve for the ammonia gas is closed. Only the silane gas is continuously made to flow on the silicon wafer for several minutes. The time is set so that the appearance of the wafer is hardly changed from that of a silicon nitride film, which has been obtained up to now, when the wafer is taken out. When the silicon nitride film is immersed in acid and wafer, it is found that liquid is strongly repelled and acid resistance and waterproof property are shown.
|
