| 摘要 |
PURPOSE:To prevent undercuts of polycrystalline Si, the damage of oxide films, and the damage of Al by a method wherein a wafer coated with reflection-preventing Si is plasma-etched with a mixed gas of fleon and carbon tetrachloride. CONSTITUTION:The Si substrate 11 is coated with an oxide film 12, a polycrystalline Si 13, Al or an Al compound 14. Thereafter, the reflection-preventing Si 15 is adhered, and a photo resist 16 is formed to a desired pattern. Next, the Si 15, Al 14, and Si 13 are selectively removed by using the resist 16 as a mask, and the resist 16 is removed. Then, the Si is removed by plasma etching in a parallel flat type plasma apparatus using a mixed gas of fleon and tetrachloride. This can remove the Si on the Al in a desired state. This gas plasma has a low rate of etching oxide films because of the content of tetrachloride, and cannot undercut polycrystalline Si. Besides, Al etching does not advance in the presence of Al fluorides on the Al surface. |
