| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a fluid separating apparatus which is small and lightweight and whose fluid separating performance is high, to obtain a silicon substrate in which a porous silicon part is formed selectively inside the silicon substrate and to obtain its formation method. SOLUTION: A silicon substrate 1 is covered with a mask layer 3 a part of which is opened. A part of the silicon substrate 1 is anodically converted from a removed part in the mark layer 3. Thereby, a porous silicon part 6 is formed to be a belt shape inside the silicon substrate 1. At this time, the porous silicon part 6 which is created by increasing a conversion current according to the growth degree of the porous silicon part 6 in such a way that a current density in the interface between the growth tip part of the porous silicon part 6 and the silicon substrate 1 becomes nearly constant during the anodic conversion process and whose porosity and thin hole diameter are uniform is used as a porous substance for fluid separation. In addition, the porous silicon part 6 is partially oxidized, an oxide film is etched, and the porosity and the thin hole diameter are controlled to a desired value.</p> |
