| 摘要 |
PURPOSE:To make it possible to make the corner part of a projection gentle and also to make a surface smooth in a second etching process by making the ratio of flow rate of a second gas to that of a first gas in this process larger than in a first etching process. CONSTITUTION:In a first etching process wherein the ratio of flow rate of a second gas containing oxygen to that of a first gas containing a halogen element is made large in some degree, the angular part of a recession is made gentle efficiently by a little amount of etching. Thereafter, the ratio of flow rate of the second gas to that of the first gas is made larger than that in the first etching process and the corner part of a projection is made gentle efficiently in a second etching process. Since the ground is not exposed according to this method, no deterioration of the ground takes place and a smooth surface can be obtained. |
