| 摘要 |
PURPOSE:To perform an etching process and a plasma oxidation process by a continuous operation without stopping plasma in the midst and also, to contrive perform the formation of a groove in a short plasma oxidizing time by a method wherein chlorine gas is used as etching gas and chlorine is mixed in oxygen as gas for protective film formation. CONSTITUTION:In a reactive ion etching method, Cl2 gas is used as reaction gas and when an etching is performed, a vertical section-shaped groove 4 is obtained. The depth of the groove 4 at this time is about 1.2 mum to its groove width of about 0.8 mum. In the etching in a comparatively short time like this, a bulge in the groove is not seen. There, when a large quantity of O2 is added to the reaction gas for stopping the etching and a treatment is performed for 30 seconds in a plasma atmosphere, a thin oxide film 5 is formed on the internal surface of the groove 4 by its reaction with silicon. In this case, the flow rate of the Cl2 gas is decreased by the control of a mass flow controller and the mixing ratio of Cl2/O2 is optimized. Thereby, an oxidative reaction is more efficiently promoted. |
