| 摘要 |
A plasma etching method is provided, which forms a penetrating hole with a size as small as approximately 0.3 mu m or less and a high aspect ratio in a doped or undoped silicon dioxide film covered with a patterned masking film. This method is comprised of a step of forming a masking film with a window on a silicon dioxide film to be etched, and a step of selectively etching the silicon dioxide film through the window of the masking film using a fluorocarbon-based etching gas and a plasma in a reaction chamber, thereby forming a penetrating hole in the silicon dioxide film. During the step of selectively etching the silicon dioxide film, an etching condition is adjusted in such a way that a fluorocarbon polymer film having a ratio of carbon to fluorine (i.e., a C/F ratio) ranging from 1.1 to 1.8 is deposited on the masking film. The masking film preferably has a thickness of approximately 1 mu m or less. It is preferred that this method is carried out using a surface-wave plasma etching apparatus.
|
