摘要 |
A method of taper-etching a layer to be etched that is made of SiO2 or SiON and has a top surface. The method includes the step of forming an etching mask with an opening on the top surface of the layer to be etched, and the step of taper-etching a portion of the layer to be etched, the portion being exposed from the opening, by reactive ion etching so that a groove having two wall faces that intersect at a predetermined angle is formed in the layer to be etched. The etching mask is formed of a material containing elemental Al. The step of taper-etching employs an etching gas that contains a main component gas, which contributes to the etching of the layer to be etched, and N2.
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