| 摘要 |
PURPOSE:To shorten the process by cleaning the inner surface of a groove formed in a silicon substrate using a cleaning liquid which is faster in the etch rate of the etching mask of the silicon substrate than in the etch rate of the substrate, thereby beveling the opening part of the groove. CONSTITUTION:With a silicon dioxide film 22 on a silicon substrate 21 as a mask, the silicon substrate 21 is etched to form a groove 25 in the substrate 21, and thereafter the inner surface of the groove 25 is cleaned using a cleaning liquid which is faster in the etch rate of the etching mask 22 than in the etch rate of the silicon substrate 21, e.g., a mixed liquid of hydrofluoric acid, acetic acid and pure water. As a result, in a groove opening part 24, the silicon substrate 21 surface surrounding the opening part 24 is exposed. And, when the substrate 21 surface surrounding the groove opening part 24 is exposed in this way, the substrate silicon of the corner section of the groove opening part 24 is etched from the lateral and vertical directions, so the corner section becomes a taper 28, whereby a groove with a taper 28 in the opening part 24 is formed. With this, the etching of the substrate can be shortened. |
