| 摘要 |
<p>The present invention is provided with a first etching step and a second etching step. In the first etching step, an etchant is ejected from a first fluid nozzle (20) and sprayed onto the etching surface of an etching object (1), whereby the etching surface is etched. In the second etching step, the etchant and a gas are mixed and ejected from a second fluid nozzle (30), and the etchant is sprayed onto the etching surface etched in the first etching step, whereby the etching surface if further etched. In the second etching step, the etchant in the form of liquid droplets smaller than those in the first etching step is sprayed onto the etching surface with a greater impact force than in the first etching step.</p> |
