| 摘要 |
PURPOSE:To avoid the irregularities in the shape of the first time anisotropical etching by the second time anisotropical etching step within a manufacturing method wherein a single crystal substrate is to be anisotropically etched away exceeding two times. CONSTITUTION:The first time anisotropical etching step is performed on a semiconductor substrate 1 using a first etching mask 2 so as to form a first recessed anisotropically etched away region. Next, the first etching mask 2 is left intact to form a second etching mask 7 for performing the second time anisotropical etching step. At this time, the first etching mask 2 is made of a material resistant to the patterning etchant for the second etching mask 7. Thus, the edge part of the first etched away region 4 can be protected to retain good shape. For example, out of respective etching masks 2, 7, one is made of a dielectric material such as silicon oxide film, etc., while the other is made of a metallic material such as Au, Ti, etc. On the other hand, potassium hydroxide water soulution is adopted as an anisotropical etchant. |
