| 摘要 |
PURPOSE:To fabricate a single crystal substrate structure with minimum necessary dimensions with no restriction of process by preventing side etching when a chip, having structure in the depth direction, is fabricated by multistage anisotropic etching process. CONSTITUTION:Three etching masks 202, 203, 204 being used in three following etchings are formed, while being superposed, on the opposite sides of a single crystal substrate 201. Anisotropic etching is conducted until a level difference, equal to at least one half of the beam thickness, is formed using the third etching mask, a bank structure 205 is formed at the beam edge part by anisotropic etching using the second etching mask 203, and then the peripheral part of beam is penetrated while thinning the beam by anisotropic etching using the first etching mask 202. Since the bank structure 205 at the beam edge part inhibits etching of the beam 206 in the breadthwise direction thereof, a target beam thickness can be obtained while keeping the original width of beam. |
